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This is a knowledge network extract, and will likely be somewhat hard to understand


This appears to be quite a benefitial substance, unfortunately I appear to be very allergic to it.

Probably helpful in normalizing Ca+ given EMF

as pill

  • don’t take prior to driving disruption of parasympathetic motor functions
  • don’t take prior to fasting or large fat consumption: PPARγ agonist . Perhpas take along splurges.
  • don’t take before sleep (since want to do fat burning during the night)

other uses

  • use in skin lotion
  • use in mouth wash: may be capable of preventing chronic inflammatory diseases induced by oral bacteria.


  • disruption of parasympathetic motor functions
  • mTOR inhibited
  • anti biofilm
  • anti amyloid
  • ! Honokiol blocked the LPS-induced cytotoxicity
  • ! positive effects on skeletal structure
  • ! anti cancer (lots of different tyeps)
    • ! suppresses both gastric tumor growth and peritoneal dissemination
    • ! anti melanoma
    • anti skin cancer
    • ! anti leukemia
    • anti tuomor
    • Honokiol traverses the blood-brain barrier and induces apoptosis of neuroblastoma
    • many more
  • anti candida
  • chondrogenesis (cartilage creation) in stem cells
  • autophagy
  • protects skin cells against inflammation, collagenolysis, apoptosis, and senescence caused by cigarette smoke damage
  • protects against renal ischemia/reperfusion injury via the suppression of oxidative stress, iNOS, inflammation and STAT3 in rats. [26647858]
  • anti-inflammatory
  • Elimination of cancer stem-like cells
  • attenuates the lipid accumulation in hepatocytes
  • enhances immune response to infection
  • inhibits hepatic steatosis
  • ! agonists (binds to and activates) of PPARγ ( a receptor tell cells to store fat)
    • probably don’t want to take it with high fat diet
    • probably want to take it during splurges
  • may be capable of preventing chronic inflammatory diseases induced by oral bacteria.
  • honokiol was identified as an inhibitor of aromatase -> more free testosterone -> better skin
  • ! effective anxiolytics, sedatives, and anti-convulsants
  • inhibitor of high-glucose-induced upregulation of inflammatory cytokine production
  • anti atherosclerosis
  • ! Protective effects of honokiol against oxidized LDL-induced cytotoxicity
  • ! possible acne-mitigating agents


  • enhance the signalling of ligands (activators) of the GABAA receptor despite not inherently activating them
  • Magnolol appears to be able to increase the overall expression of GABAA receptors with alpha type subunits. This may be biologically relevant following oral ingestion
  • The standard neuroprotective effects of magnolol appear to extend to dopaminergic neurons
  • Magnolol appears to be able to inhibit the aldose reductase enzyme, which inhibits AGE formation and may reduce the side-effects typically associated with diabetes (retinopathy, neuropathy, nephropathy, etc.)
  • honokiol at 3-10µM is able to enhance glucose uptake to a similar degree as 3-10µM pioglitazone (without influencing fat cell differentiation)
  • Partial agonists of the PPARγ receptor appear to be able to preserve the antidiabetic effects of this receptor without activating the pro-obesogenic effects, and honokiol appears to be a partial agonist
  • Honokiol, in particular, appears to be effective in reducing or alleviating tumor growth and occurrence in vitro[86][94][95][96] and in vivo.[24]


! !

Honokiol blocks store operated calcium entry in CHO cells expressing the M3 muscarinic receptor: honokiol and muscarinic signaling. [23432810]
Honokiol, a cell-permeable phenolic compound derived from the bark of magnolia trees and present in Asian herbal teas, has a unique array of pharmacological actions, including the inhibition of multiple autonomic responses. We determined the effects of honokiol on calcium signaling underlying transmission mediated by human M3 muscarinic receptors expressed in Chinese hamster ovary (CHO) cells. Receptor binding was determined in radiolabelled ligand binding assays; changes in intracellular calcium concentrations were determined using a fura-2 ratiometric imaging protocol; cytotoxicity was determined using a dye reduction assay.
-   Honokiol had a potent (EC50 ≈ 5 μmol/l) inhibitory effect on store operated calcium entry (SOCE) that was induced by activation of the M3 receptors. This effect was specific, rapid and partially reversible, and was seen at concentrations not associated with cytotoxicity, inhibition of IP3 receptor-mediated calcium release, depletion of ER calcium stores, or disruption of M3 receptor binding.
-   It is likely that an inhibition of SOCE contributes to honokiol disruption of parasympathetic motor functions, as well as many of its beneficial pharmacological properties.
Mesh:Animals,Biphenyl Compounds,CHO Cells,Calcium,Calcium Signaling,Cricetinae,Cytoplasm,Gene Expression Regulation,Humans,Inositol 1,4,5-Trisphosphate,Ion Transport,Lignans,Receptor, Muscarinic M3
  • Honokiol had a potent inhibitory effect on store operated calcium entry (SOCE) that was induced by activation of the M3 receptors. This effect was specific, rapid and partially reversible, and was seen at concentrations not associated with cytotoxicity, inhibition of IP3 receptor-mediated calcium release, depletion of ER calcium stores, or disruption of M3 receptor binding.
  • It is likely that an inhibition of SOCE contributes to honokiol disruption of parasympathetic motor functions, as well as many of its beneficial pharmacological properties.

Antimicrobial activity of honokiol and magnolol isolated from Magnolia officinalis. [11268114]
The antimicrobial activity of honokiol and magnolol, the main constituents of Magnolia officinalis was investigated. The antimicrobial activity was assayed by the agar dilution method using brain heart infusion medium and the minimum inhibitory concentration (MIC) were determined for each compound using a twofold serial dilution assay. The results showed that honokiol and magnolol have a marked antimicrobial effect (MIC = 25 microg/mL) against Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Micrococcus luteus and Bacillus subtilis, but did not show antimicrobial activity (MIC > or = 100 microg/mL) for Shigella flexneii, Staphylococcus epidermidis, Enterobacter aerogenes, Proteus vulgaris, Escherichia coli and Pseudomonas aeruginosa. Our results indicate that honokiol and magnolol, although less potent than tetracycline, show a significant antimicrobial activity for periodontal pathogens. Hence we suggest that honokiol and magnolol might have the potential to be an adjunct in the treatment of periodontitis.
Mesh:Actinobacillus,Anti-Bacterial Agents,Bacillus,Bacteria,Biphenyl Compounds,Drugs, Chinese Herbal,Humans,Lignans,Magnoliopsida,Microbial Sensitivity Tests,Micrococcus,Periodontal Diseases,Plants, Medicinal,Porphyromonas,Prevotella
potential to be an adjunct in the treatment of periodontitis

Antifungal activity of magnolol and honokiol. [10728656]
Two neolignan compounds, magnolol (5,5′-diallyl-2,2′-dihydroxybiphenyl, 1) and honokiol (5,5′-diallyl-2,4′-dihydroxybiphenyl, 2), were isolated from the stem bark of Magnolia obovata and evaluated for antifungal activity against various human pathogenic fungi. Compound 1 and 2 showed significant inhibitory activities against Trichophyton mentagrophytes, Microsporium gypseum, Epidermophyton floccosum, Aspergillus niger, Cryptococcus neoformans, and Candida albicans with minimum inhibitory concentrations (MIC) in a range of 25-100 microg/ml. Therefore, compound 1 and 2 could be used as lead compounds for the development of novel antifungal agents.
Mesh:Antifungal Agents,Biphenyl Compounds,Humans,Lignans,Microbial Sensitivity Tests
novel antifungal agents

Antimicrobial activity of magnolol and honokiol against periodontopathic microorganisms. [9619121]
Magnolol (1) and honokiol (2), main compounds from the stem bark of Magnolia obovata Thunb., were evaluated for an antimicrobial activity against periodontopathic microorganisms, Porphyromonas gingivalis, Prevotella gingivalis, Actinobacillus actinomycetemcomitans, Capnocytophaga gingivalis, and Veillonella disper, and a cytotoxicity against human gingival fibroblasts and epithelial cells. Our results indicate that magnolol and honokiol, although less potent than chlorhexidine, show a significant antimicrobial activity against these microorganisms, and a relatively low cytotoxic effect on human gingival cells. Thus, it is suggested that magnolol and honokiol may have a potential therapeutic use as a safe oral antiseptic for the prevention and the treatment of periodontal disease.
Mesh:Aggregatibacter actinomycetemcomitans,Anti-Bacterial Agents,Biphenyl Compounds,Capnocytophaga,Cells, Cultured,Epithelial Cells,Fibroblasts,Gingiva,Humans,Lignans,Porphyromonas gingivalis,Prevotella,Veillonella
against periodontopathic microorganisms

Anti-inflammatory effects of magnolol and honokiol are mediated through inhibition of the downstream pathway of MEKK-1 in NF-kappaB activation signaling. [15856410]
Propionibacterium acnes, an anaerobic pathogen, plays an important role in the pathogenesis of acne and seems to initiate the inflammatory process by producing proinflammatory cytokines. In order to demonstrate the anti-inflammatory effects and action mechanisms of magnolol and honokiol, several methods were employed. Through DPPH and SOD activity assays, we found that although both magnolol and honokiol have antioxidant activities, honokiol has relatively stronger antioxidant activities than magnolol {[for DPPH assay, % of DPPH bleaching of magnolol and honokiol (500 microM magnolol: 19.8%; 500 microM honokiol: 67.3%)]; [for SOD assay, SOD activity (200 microM magnolol: 53.4%; 200 microM honokiol: 64.3%)]}. Moreover, the production of interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-alpha) induced by P. acnes in THP-1 cells, a human monocytic cell line, was reduced by magnolol and honokiol {[for IL-8 (10 microM magnolol: 42.7% inhibition; 10 microM honokiol: 51.4% inhibition)]; [for TNF-alpha (10 microM magnolol: 20.3% inhibition; 10 microM honokiol: 39.0% inhibition)]}. Cyclooxygenase-2 (Cox-2) activity was also suppressed by them [(15 microM magnolol: 45.8% inhibition), (15 microM honokiol: 66.3% inhibition)]. Using a nuclear factor-kappaB (NF-kappaB) luciferase reporter assay system and Western analysis, we identified that magnolol and honokiol exert their anti-inflammatory effects by inhibiting the NF-kappaB element, which exists in Cox-2, IL-8, and TNF-alpha promoters [(15 microM magnolol: 44.8% inhibition), (15 microM honokiol: 42.3% inhibition)]. Of particular note is that magnolol and honokiol operate downstream of the MEKK-1 molecule. Together with their previously known antibacterial activity against P. acnes and based on these results, we suggest that magnolol and honokiol may be introduced as possible acne-mitigating agents.
Mesh:Anti-Bacterial Agents,Anti-Inflammatory Agents, Non-Steroidal,Antioxidants,Biphenyl Compounds,Cytokines,Humans,Interleukin-8,Lignans,MAP Kinase Kinase Kinase 1,Magnolia,Microbial Sensitivity Tests,Monocytes,NF-kappa B,Phytotherapy,Picrates,Plant Extracts,Propionibacterium acnes,Superoxide Dismutase,Tumor Necrosis Factor-alpha
! possible acne-mitigating agents

Protective effects of honokiol against oxidized LDL-induced cytotoxicity and adhesion molecule expression in endothelial cells. [16580656]
Honokiol, a compound extracted from Chinese medicinal herb Magnolia officinalis, has several biological effects. However, its protective effects against endothelial injury remain unclarified. In this study, we examined whether honokiol prevented oxidized low-density lipoprotein (oxLDL)-induced vascular endothelial dysfunction. Incubation of oxLDL with honokiol (2.5-20 microM) inhibited copper-induced oxidative modification as demonstrated by diene formation, thiobarbituric acid reactive substances (TBARS) assay and electrophoretic mobility assay. Expression of adhesion molecules (ICAM, VCAM and E-selectin) and endothelial NO synthase (eNOS) affected by oxLDL was investigated by flow cytometry and Western blot. We also measured the production of reactive oxygen species (ROS) using the fluorescent probe 2′,7′-dichlorofluorescein acetoxymethyl ester (DCF-AM). Furthermore, several apoptotic phenomena including increased cytosolic calcium, alteration of mitochondrial membrane potential, cytochrome c release and activation of caspase-3 were also investigated. Apoptotic cell death was characterized by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) stain. The results showed that honokiol prevented the copper-induced oxidative modification of LDL. Honokiol also ameliorated the oxLDL-diminished eNOS protein expression and reduced the oxLDL-induced adhesion molecules and the adherence of THP-1 cells to HUVECs. Furthermore, honokiol attenuated the oxLDL-induced cytotoxicity, apoptotic features, ROS generation, intracellular calcium accumulation and the subsequent mitochondrial membrane potential collapse, cytochrome c release and activation of caspase-3. Our results suggest that honokiol may have clinical implications in the prevention of atherosclerotic vascular disease.
Mesh:Antioxidants,Apoptosis,Biphenyl Compounds,Calcium,Caspase 3,Caspases,Cell Adhesion,Cell Line,Cytochromes c,E-Selectin,Endothelial Cells,Humans,Intercellular Adhesion Molecule-1,Lignans,Lipoproteins, LDL,Membrane Potentials,Mitochondria,Nitric Oxide Synthase Type III,Reactive Oxygen Species,Vascular Cell Adhesion Molecule-1
! Protective effects of honokiol against oxidized LDL-induced cytotoxicity

Inhibitory effects of honokiol on LPS and PMA-induced cellular responses of macrophages and monocytes. [19788858]
The regulatory effects of honokiol on the cellular responses of macrophages and monocytes were evaluated. Specifically, we investigated the effects of honokiol with respect to lipopolysaccharide (LPS)-induced cytotoxicity, LPS- or phorbol-12-myristate-13-acetate (PMA)-mediated morphological changes, and relevant events (FITC-dextran-induced phagocytic uptake). Honokiol blocked the LPS-induced cytotoxicity of RAW264.7 cells in a dose-dependent manner. In addition, honokiol appeared to block the production of cytotoxic cytokines such as interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha, nitric oxide (NO), and reactive oxygen species (ROS). Moreover, honokiol strongly prevented the morphological changes in RAW 264.7 and U937 cells that were induced by LPS and PMA. The surface levels of marker proteins, which are up-regulated under the morphological changes of RAW264.7 and U937 cells, were also diminished. The data presented here strongly suggest that the honokiol modulates various cellular responses managed by macrophages and monocytes. [BMB reports 2009; 42(9): 574-579].
Mesh:Anti-Allergic Agents,Biphenyl Compounds,Carcinogens,Cells, Cultured,Humans,Interleukin-1beta,Lignans,Lipopolysaccharides,Macrophages,Monocytes,Nitric Oxide,Nitric Oxide Synthase,Reactive Oxygen Species,Tetradecanoylphorbol Acetate,Tumor Necrosis Factor-alpha,U937 Cells
! Honokiol blocked the LPS-induced cytotoxicity

Honokiol is a potent scavenger of superoxide and peroxyl radicals. [18640101]
Honokiol, a compound extracted from Magnolia officinalis, has antitumor and antiangiogenic properties in several tumor models in vivo. Among the downstream pathways inhibited by honokiol is nuclear factor kappa beta (NFkappabeta). A prime physiologic stimulus of NFkappabeta is reactive oxygen species. The chemical structure of honokiol suggests that it may be an effective scavenger of reactive oxygen species. In this work, we have studied the reactions of honokiol with superoxide and peroxyl radicals in cell-free and cellular systems using electron spin resonance (ESR) and high-performance liquid chromatography (HPLC) techniques. Honokiol efficiently scavenged superoxide radicals in xanthine oxidase and cytochrome P-450 cell-free systems with the rate constant 3.2×10(5)M(-1)s(-1), which is similar to reactivity of ascorbic acid but 20-times higher than reactivity of vitamin E analog trolox. Honokiol potently scavenged intracellular superoxide within melanoma cells. In addition, honokiol scavenged peroxyl radicals generated by 2,2′-azo-bis(2-amidinopropane hydrochloride) (AAPH). The rate constant of the reaction of honokiol with peroxyl radicals (1.4×10(6)M(-1)s(-1)) was calculated from the competition with spin trap 5-(ethoxycarbonyl)-5-methyl-1-pyrroline N-oxide (EMPO), and was found close to reactivity of trolox (2.5×10(6)M(-1)s(-1)). Therefore, honokiol is an effective scavenger of both superoxide and peroxyl radicals, which may be important for physiological activity of honokiol.
Mesh:Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Cell Line, Tumor,Chromatography, High Pressure Liquid,Electron Spin Resonance Spectroscopy,Free Radical Scavengers,Humans,Kinetics,Lignans,Peroxides,Spin Labels,Superoxides
potent scavenger of superoxide and peroxyl radicals

Honokiol: an effective inhibitor of high-glucose-induced upregulation of inflammatory cytokine production in human renal mesangial cells. [20582713]
To evaluate the regulatory effects of honokiol on high-glucose (HG)-induced inflammatory responses of human renal mesangial cells (HRMCs).
-   We performed MTS assays to determine the non-cytotoxic concentration of honokiol for HRMCs. Enzyme-linked immunosorbent assays were performed to analyze the expressions of the proteins interleukin (IL)-1β, IL-18, tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β1, monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1α, RANTES, and prostaglandin (PG) E2. The total nitric oxide (NO) concentration was determined using the Griess reaction.
-   Treatment with 50 mmol/L glucose markedly increased the level of IL-1β, IL-18, TNF-α, PGE2, NO, TGF-β1, MCP-1, MIP-1α, and RANTES. Honokiol (~20 μmol/L) treatment inhibited the HG-induced expression of inflammatory cytokines such as IL-1β, IL-18, TNF-α, PGE2, NO, and TGF-β1 in a dose-dependent manner. Moreover, it markedly inhibited the expression of chemokines such as MCP-1, MIP-1α, and RANTES, which are upregulated under HG conditions.
-   Honokiol inhibits the HG-induced expression of inflammatory factors in HRMCs. Honokiol may be considered a promising drug with potent anti-inflammatory activities in addition to its strong anti-cancer, anti-angiogenesis, and anti-neurodegenerative effects.
Mesh:Animals,Anti-Allergic Agents,Biphenyl Compounds,Cell Survival,Cells, Cultured,Cytokines,Glucose,Humans,Lignans,Mesangial Cells,Up-Regulation
  • inhibitor of high-glucose-induced upregulation of inflammatory cytokine production

Identification of a naturally occurring rexinoid, honokiol, that activates the retinoid X receptor. [20695472]
Screening of a total of 86 crude drugs for retinoid X receptor (RXR) ligands demonstrated that the methanol extract of the bark of Magnolia obovata markedly activated the transcriptional activity of RXRalpha in luciferase reporter assays. Thereafter, honokiol (1) was isolated as a constituent able to activate RXR selectively as a natural rexinoid, but not RARalpha. The activity of 1 was more potent than those of phytanic acid and docosahexaenoic acid, both of which are known to be natural RXR agonists. Honokiol (1) is capable of activating a RXR/LXR heterodimer, resulting in the induction of ATP-binding cassette transporter A1 mRNA and protein expression in RAW264.7 cells, as well as an increase in [(3)H]cholesterol efflux from peritoneal macrophages. These effects of 1 were enhanced synergistically in the presence of an LXR agonist, 22(R)-hydroxycholesterol. The results obtained demonstrate that 1, a newly identified natural rexinoid, regulates the functions of RXR/LXR heterodimer and abrogates foam cell formation by the induction of ABCA1 via activation of the RXR/LXR heterodimer.
Mesh:ATP Binding Cassette Transporter 1,ATP-Binding Cassette Transporters,Animals,Biphenyl Compounds,Cholesterol,Humans,Ligands,Lignans,Macrophages,Magnolia,Male,Mice,Mice, Inbred Strains,Molecular Structure,Plant Bark,Plants, Medicinal,Receptors, Retinoic Acid,Retinoic Acid Receptor alpha,Retinoid X Receptors,Tetrahydronaphthalenes

Honokiol isolated from Magnolia officinalis stimulates osteoblast function and inhibits the release of bone-resorbing mediators. [21621646]
There has been a strong interest in searching for natural therapies for osteoporosis. Honokiol is a phenolic compound isolated from the bark of Magnolia officinalis, a plant widely used in traditional medicine. In the present study, the effects of honokiol on the function of osteoblastic MC3T3-E1 cells were studied. Honokiol caused a significant elevation of cell growth, alkaline phosphatase activity, collagen synthesis, mineralization, glutathione content, and osteoprotegerin release in the cells (P<0.05). Moreover, honokiol significantly (P<0.05) decreased the production of osteoclast differentiation inducing factors such as TNF-α, IL-6, and receptor activator of nuclear factor-kB ligand (RANKL) in the presence of antimycin A, which inhibits mitochondrial electron transport and has been used as a ROS generator. These results demonstrate that honokiol may have positive effects on skeletal structure.
Mesh:Alkaline Phosphatase,Animals,Antimycin A,Biphenyl Compounds,Bone Resorption,Calcification, Physiologic,Cell Growth Processes,Cell Line,Collagen,Glutathione,Humans,Interleukin-6,Lignans,Magnolia,Mice,Osteoblasts,Osteoporosis,Osteoprotegerin,Phytotherapy,RANK Ligand,Tumor Necrosis Factor-alpha
positive effects on skeletal structure

Honokiol traverses the blood-brain barrier and induces apoptosis of neuroblastoma cells via an intrinsic bax-mitochondrion-cytochrome c-caspase protease pathway. [22259050]
Neuroblastomas, an embryonic cancer of the sympathetic nervous system, often occur in young children. Honokiol, a small-molecule polyphenol, has multiple therapeutic effects and pharmacological activities. This study was designed to evaluate whether honokiol could pass through the blood-brain barrier (BBB) and induce death of neuroblastoma cells and its possible mechanisms. Primary cerebral endothelial cells (CECs) prepared from mouse brain capillaries were cultured at a high density for 4 days, and these cells formed compact morphologies and expressed the ZO-1 tight-junction protein. A permeability assay showed that the CEC-constructed barrier obstructed the passing of FITC-dextran. Analyses by high-performance liquid chromatography and the UV spectrum revealed that honokiol could traverse the CEC-built junction barrier and the BBB of ICR mice. Exposure of neuroblastoma neuro-2a cells and NB41A3 cells to honokiolinduced cell shrinkage and decreased cell viability. In parallel, honokiol selectively induced DNA fragmentation and cell apoptosis rather than cell necrosis. Sequential treatment of neuro-2a cells with honokiol increased the expression of the proapoptotic Bax protein and its translocation from the cytoplasm to mitochondria. Honokiol successively decreased the mitochondrial membrane potential but increased the release of cytochrome c from mitochondria. Consequently, honokiol induced cascade activation of caspases-9, -3, and -6. In comparison, reducing caspase-6 activity by Z-VEID-FMK, an inhibitor of caspase-6, simultaneously attenuated honokiol-induced DNA fragmentation and cell apoptosis. Taken together, this study showed that honokiol can pass through the BBB and induce apoptotic insults to neuroblastoma cells through a Bax-mitochondrion-cytochrome c-caspase protease pathway. Therefore, honokiol may be a potential candidate drug for treating brain tumors.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Blood-Brain Barrier,Brain Neoplasms,Caspases,Cell Line, Tumor,Cell Survival,Cells, Cultured,Cytochromes c,DNA Fragmentation,Endothelial Cells,Humans,Lignans,Membrane Potential, Mitochondrial,Mice,Mice, Inbred ICR,Mitochondria,Neuroblastoma,Proto-Oncogene Proteins c-bcl-2,Tight Junctions,bcl-2-Associated X Protein
Honokiol traverses the blood-brain barrier and induces apoptosis of neuroblastoma

The natural products magnolol and honokiol are positive allosteric modulators of both synaptic and extra-synaptic GABA(A) receptors. [22445602]
The National Center for Complementary and Alternative Medicine (NCCAM) estimates that nearly 40% of adults in the United States use alternative medicines, often in the form of an herbal supplement. Extracts from the tree bark of magnolia species have been used for centuries in traditional Chinese and Japanese medicines to treat a variety of neurological diseases, including anxiety, depression, and seizures. The active ingredients in the extracts have been identified as the bi-phenolic isomers magnolol and honokiol. These compounds were shown to enhance the activity of GABA(A) receptors, consistent with their biological effects. The GABA(A) receptors exhibit substantial subunit heterogeneity, which influences both their functional and pharmacological properties. We examined the activity of magnolol and honokiol at different populations of both neuronal and recombinant GABA(A) receptors to characterize their mechanism of action and to determine whether sensitivity to modulation was dependent upon the receptor’s subunit composition. We found that magnolol and honokiol enhanced both phasic and tonic GABAergic neurotransmission in hippocampal dentate granule neurons. In addition, all recombinant receptors examined were sensitive to modulation, regardless of the identity of the α, β, or γ subunit subtype, although the compounds showed particularly high efficacy at δ-containing receptors. This direct positive modulation of both synaptic and extra-synaptic populations of GABA(A) receptors suggests that supplements containing magnolol and/or honokiol would be effective anxiolytics, sedatives, and anti-convulsants. However, significant side-effects and risk of drug interactions would also be expected.
Mesh:Animals,Biphenyl Compounds,Drugs, Chinese Herbal,GABA Agents,HEK293 Cells,Hippocampus,Humans,Inhibitory Postsynaptic Potentials,Lignans,Neurons,Rats,Receptors, GABA-A,Synaptic Transmission
effective anxiolytics, sedatives, and anti-convulsants

A naturally occurring rexinoid, honokiol, can serve as a regulator of various retinoid x receptor heterodimers. [22223330]
We investigated the properties of honokiol, a natural rexinoid, as a regulator of retinoid X receptor (RXR) heterodimers with various partner nuclear receptors (NRs), in comparison with those of the synthetic rexinoid bexarotene. Honokiol alone was hardly capable of activating peroxisome proliferator-activated receptor (PPAR) γ/RXR, RXR/liver X receptor (LXR), and RXR/vitamin D receptor (VDR) heterodimers, whereas it effectively potentiated their activation by agonists for the partner NRs of the RXR heterodimers. These findings were further supported by increased mRNA and protein levels for the respective NR target genes. Bexarotene alone activated PPARγ/RXR and RXR/LXR heterodimers, but not RXR/VDR heterodimers, and facilitated the activation of all three RXR heterodimers by the respective PPARγ, LXR, and VDR agonists. When the potencies of honokiol and bexarotene were compared, honokiol was able to serve as a subsidiary agonist in the activation of RXR heterodimers in a similar manner to bexarotene. However, it seemed to potentiate the activation of PPARγ/RXR heterodimers by the PPARγ agonist rosiglitazone more efficiently than bexarotene, and was a less potent RXR agonist than bexarotene. In conclusion, we have demonstrated that honokiol is a rexinoid that possesses distinct properties from bexarotene, and mainly has subsidiary roles in the activation of RXR heterodimers by potentiating the activation of RXR heterodimers by agonists for the partner NRs.
Mesh:3T3-L1 Cells,Animals,Anticarcinogenic Agents,Biphenyl Compounds,Caco-2 Cells,Dimerization,Humans,Lignans,Liver X Receptors,Magnolia,Mice,Orphan Nuclear Receptors,PPAR gamma,Plant Extracts,RNA, Messenger,Receptors, Calcitriol,Receptors, Cytoplasmic and Nuclear,Retinoid X Receptors,Signal Transduction,Tetrahydronaphthalenes,Thiazolidinediones

Modulating testosterone pathway: a new strategy to tackle male skin aging? [23049247]
In men, the level of testosterone decreases with age. At the skin level, the result is observed as a decrease in density and in a lower elasticity. Identifying compounds that are able to increase the level of testosterone appears to be an attractive strategy to develop new antiaging bioactive ingredients for men. Reverse pharmacognosy was successfully applied to identify new natural compounds able to modulate testosterone levels. Among several in silico hits, honokiol was retained as a candidate as it has the greatest potential to become an active ingredient. This result was then validated in vitro on aromatase and 5-alpha-reductase type 1 and 2, which are two types of enzymes implicated in the degradation of free testosterone. Indeed, honokiol was identified as an inhibitor of aromatase, with a half-maximal inhibitory concentration (IC(50)) of about 50 μM. In addition, honokiol was shown to be an inhibitor of 5-alpha-reductase type 1, with an IC(50) of about 75 μM. Taken together, these data indicate that honokiol modulates testosterone levels, and its structure has the potential to serve as a lead for future designs of highly selective inhibitors of 5-alpha-reductase type 1.
Mesh:3-Oxo-5-alpha-Steroid 4-Dehydrogenase,Animals,Aromatase,Biphenyl Compounds,Dose-Response Relationship, Drug,Drugs, Chinese Herbal,Enzyme Inhibitors,Humans,Lignans,Magnolia,Male,Middle Aged,Skin Aging,Structure-Activity Relationship,Testosterone
Keywords:dermopharmacy,honokiol,man cosmetics,reverse pharmacognosy,testosterone
honokiol was identified as an inhibitor of aromatase

Comparative inhibitory effects of magnolol, honokiol, eugenol and bis-eugenol on cyclooxygenase-2 expression and nuclear factor-kappa B activation in RAW264.7 macrophage-like cells stimulated with fimbriae of Porphyromonas gingivalis. [23160676]
The anti-inflammatory activity of magnolol and related compounds is currently a focus of interest. In the present study, the inhibitory effects of these compounds on cyclooxygenase (COX-2) expression and nuclear factor-kappa B (NF-κB) activation were investigated in RAW264.7 macrophage-like cells stimulated with the fimbriae of Porphyromonas gingivalis, an oral anaerobe.
-   The cytotoxicity of magnolol, honokiol, eugenol and bis-eugenol against RAW264.7 cells was determined using a cell counting kit (CCK-8). The regulatory effect of these compounds on the expression of COX-2 mRNA, stimulated by exposure to the fimbriae was investigated by real-time polymerase chain reaction (PCR). NF-κB activation was evaluated by enzyme-linked immunosorbent assay (ELISA)-like microwell colorimetric transcription factor activity assay (Trans-AM) and western blot analysis. The radical-scavenging activity was determined using the induction period method in the methyl methacrylate-azobisisobutyronitrile (AIBN) polymerization system under nearly anaerobic conditions. The phenolic bond dissociation enthalpy (BDE) and orbital energy were calculated at the density functional theory (DFT) B3LYP/6-31G* level.
-   The cytotoxicity against RAW264.7 cells declined in the order bis-eugenol>eugenol> honokiol>magnolol, whereas the radical-scavenging activity declined in the order honokiol, bis-eugenol>magnolol> eugenol. Magnolol and honokiol significantly inhibited the fimbria-induced expression of COX-2 at non-cytotoxic concentrations. Both the fimbria-stimulated binding of NF-κB to its consensus sequence and phosphorylation-dependent proteolysis of inhibitor κB-α were markedly inhibited by magnilol and honokiol, whereas eugenol and bis-eugenol did not inhibit COX-2 expression and NF-κB activation. Magnolol and honokiol possessed a high electronegativity (χ) value.
-   Magnolol and honokiol exhibit antioxidative activity, low cytotoxicity, and anti-inflammatory activity. These compounds may be capable of preventing chronic inflammatory diseases induced by oral bacteria.
Mesh:Animals,Anti-Inflammatory Agents,Biphenyl Compounds,Cell Count,Cell Line,Cyclooxygenase 2,Eugenol,Fimbriae Proteins,Gene Expression Regulation,Humans,Inflammation,Lignans,Macrophages,Mice,NF-kappa B,Porphyromonas gingivalis
  • may be capable of preventing chronic inflammatory diseases induced by oral bacteria.

Maximizing dermal targeting and minimizing transdermal penetration by magnolol/honokiol methoxylation. [23380623]
Magnolol and honokiol, predominant active compounds in the family Magnoliaceae, are known to exhibit strong anti-inflammatory activities against dermal disorders. We attempted to modify the structures of magnolol and honokiol by methoxylation to optimize the skin delivery ability. Absorption of these permeants into and through the skin was performed at both an infinite dose and saturated solubility. Superoxide anion and elastase released from human neutrophils were the biomarkers used to examine anti-inflammatory potencies of these permeants. The safety of the permeants was evaluated by keratinocyte viability and in vivo bioengineering techniques. Topical magnolol and honokiol at an infinite dose (7.5 mM) showed skin accumulations of 0.22 and 0.16 nmol/mg, respectively. Methoxylation significantly enhanced their skin absorption. Deposition amounts of dimethylmagnolol and dimethylhonokiol were respectively 15- and 7-fold greater than those of magnolol and honokiol. Contrary to the skin accumulation results, the transdermal penetration across skin decreased following methoxylation. No transdermal delivery occurred for dimethylhonokiol. Skin uptake of 4′-O-methylhonokiol was 2-fold higher than that of 2-O-methylhonokiol, although they are isomers. Methoxylated permeants demonstrated selective absorption into follicles, which showed 3-5-fold higher follicular amounts compared to magnolol and honokiol. The relative order of anti-inflammatory activities was honokiol>2-O-methylmagnolol>dimethylhonokiol>magnolol. The other compounds exhibited negligible or negative responses in activated neutrophils. Magnolol and honokiol induced slight but significant keratinocyte cytotoxicity and stratum corneum disruption. Daily administration of methoxylated permeants, especially dimethylhonokiol, produced no skin irritation for up to 7 days. Methoxylated magnolol and honokiol can be efficient and safe candidates for treating inflammatory skin disorders.
Mesh:Adult,Animals,Anti-Inflammatory Agents,Biphenyl Compounds,Cell Survival,Cells, Cultured,Female,Humans,In Vitro Techniques,Keratinocytes,Lignans,Mice,Mice, Nude,Neutrophils,Pancreatic Elastase,Skin,Skin Absorption,Skin Irritancy Tests,Superoxides,Swine,Young Adult
– treating inflammatory skin disorders

Effect of honokiol on erythrocytes. [23673313]
Honokiol ((3,5-di-(2-propenyl)-1,1-biphenyl-2,2-diol), a component of Magnolia officinalis, stimulates apoptosis and is thus considered for the treatment of malignancy. In analogy to apoptosis of nucleated cells, erythrocytes may enter eryptosis, a suicidal death characterized by cell shrinkage and by breakdown of cell membrane phosphatidylserine asymmetry with phosphatidylserine-exposure at the erythrocyte surface. Eryptosis may be triggered following increase of cytosolic Ca(2+)-activity ([Ca(2+)]i). The present study explored, whether honokiol elicits eryptosis. Cell volume has been estimated from forward scatter, phosphatidylserine-exposure from annexin V binding, hemolysis from hemoglobin release, [Ca(2+)]i from Fluo3-fluorescence, and ceramide from fluorescent antibodies. As a result, a 48 h exposure to honokiol was followed by a slight but significant increase of [Ca(2+)]i (15 μM), significant decrease of forward scatter (5 μM), significant increase of annexin-V-binding (5 μM) and significant increase of ceramide formation (15 μM). Honokiol further induced slight, but significant hemolysis. Honokiol (15 μM) induced annexin-V-binding was significantly blunted but not abrogated in the nominal absence of extracellular Ca(2+). In conclusion, honokiol triggers suicidal erythrocyte death or eryptosis, an effect at least in part due to stimulation of Ca(2+) entry and ceramide formation.
Mesh:Biphenyl Compounds,Calcium,Cell Death,Cell Size,Cells, Cultured,Erythrocytes,Hemolysis,Humans,Lignans,Phosphatidylserines
Keywords:Calcium,Cell volume,Eryptosis,Honokiol,Phosphatidylserine
– blood cell apoptosis

Honokiol: a non-adipogenic PPARγ agonist from nature. [23811337]
Peroxisome proliferator-activated receptor gamma (PPARγ) agonists are clinically used to counteract hyperglycemia. However, so far experienced unwanted side effects, such as weight gain, promote the search for new PPARγ activators.
– We used a combination of in silico, in vitro, cell-based and in vivo models to identify and validate natural products as promising leads for partial novel PPARγ agonists.
– The natural product honokiol from the traditional Chinese herbal drug Magnolia bark was in silico predicted to bind into the PPARγ ligand binding pocket as dimer. Honokiol indeed directly bound to purified PPARγ ligand-binding domain (LBD) and acted as partial agonist in a PPARγ-mediated luciferase reporter assay. Honokiol was then directly compared to the clinically used full agonist pioglitazone with regard to stimulation of glucose uptake in adipocytes as well as adipogenic differentiation in 3T3-L1 pre-adipocytes and mouse embryonic fibroblasts. While honokiol stimulated basal glucose uptake to a similar extent as pioglitazone, it did not induce adipogenesis in contrast to pioglitazone. In diabetic KKAy mice oral application of honokiol prevented hyperglycemia and suppressed weight gain.
– We identified honokiol as a partial non-adipogenic PPARγ agonist in vitro which prevented hyperglycemia and weight gain in vivo.
– This observed activity profile suggests honokiol as promising new pharmaceutical lead or dietary supplement to combat metabolic disease, and provides a molecular explanation for the use of Magnolia in traditional medicine.
Mesh:3T3-L1 Cells,Adipose Tissue,Animals,Biological Products,Biphenyl Compounds,Cell Differentiation,Diabetes Mellitus, Experimental,HEK293 Cells,Humans,Lignans,Mice,Molecular Docking Simulation,PPAR gamma
Keywords:3-isobutyl-1-methylxanthine,AMP-activated kinase,AMPK,ANOVA,ATCC,American type culture collection,BADGE,BMP,BSA,CMCNa,DMEM,DMSO,Dulbecco’s modified Eagle’s medium,EC(50),EGFP,FCS,GST,HPLC,IBMX,LBD,MEF,Metabolic disease,NADPH-dependent oxidase,NBS,NF-κB,NMR,NOX,Natural product,PBS,PPARγ,Peroxisome proliferator-activated receptor,RXR,SEM,SPF,SREBP,TCM,TLC,TR-FRET,analysis of variance,bisphenol A diglycidyl ether,bone morphogenic protein 4,bovine serum albumin,dimethyl sulfoxide,effective concentration 50%,enhanced green fluorescent protein,fetal calf serum,glutathione-S-transferase,high-performance liquid chromatography,ligand-binding domain,mTOR,mammalian target of rapamycin,mouse embryonic fibroblasts,newborn bovine serum,nuclear factor κB,nuclear magnetic resonance,peroxisome proliferator-activated receptor gamma,phosphate buffered saline,retinoic X receptor,sodium carboxymethyl cellulose,specific pathogen free,standard error of the mean,sterol regulatory element binding protein,thin layer chromatography,time-resolved fluorescence resonance energy transfer,traditional Chinese medicine

Honokiol causes the p21WAF1-mediated G(1)-phase arrest of the cell cycle through inducing p38 mitogen activated protein kinase in vascular smooth muscle cells. [16962592]
Honokiol, an active component in extracts of Magnolia officinalis, has been proposed to play a role in anti-inflammatory, antioxidant activity, anti-angiogenic and anti-tumor activity. Although honokiol has a variety of pharmacological effects on certain cell types, its effects on vascular smooth muscle cells (VSMC) are unclear. This issue was investigated in the present study, honokiol was found to inhibit cell viability and DNA synthesis in cultured VSMC. These inhibitory effects were associated with G1 cell cycle arrest. Treatment with honokiol blocks the cell cycle in the G1 phase, down-regulates the expression of cyclins and CDKs and up-regulates the expression of p21WAF1, a CDK inhibitor. While honokiol did not up-regulate p27, it caused an increase in the promoter activity of the p21WAF1 gene. Immunoblot and deletion analysis of the p21WAF1 promoter showed that honokiol induced the expression of p21WAF1 and that this expression was independent of the p53 pathway. Furthermore, the honokiol-mediated signaling pathway involved in VSMC growth inhibition was examined. Among the relevant pathways, honokiol induced a marked activation of p38 MAP kinase and JNK. The expression of dominant negative p38 MAP kinase and SB203580, a p38 MAP kinase specific inhibitor, blocked the expression of honokiol-dependent p38 MAP kinase and p21WAF1. Consistently, blockade of p38 MAPK kinase function reversed honokiol-induced VSMC proliferation and cell cycle proteins. These data demonstrate that the p38 MAP kinase pathway participates in p21WAF1 induction, subsequently leading to a decrease in the levels of cyclin D1/CDK4 and cyclin E/CDK2 complexes and honokiol-dependent VSMC growth inhibition. In conclusion, these findings concerning the molecular mechanisms of honokiol in VSMC provides a theoretical basis for clinical approaches to the use therapeutic agents in treating atherosclerosis.
Mesh:Antineoplastic Agents, Phytogenic,Atherosclerosis,Base Sequence,Biphenyl Compounds,Cell Survival,Cells, Cultured,Cyclin-Dependent Kinase Inhibitor p21,Cyclins,Down-Regulation,Enzyme Activation,Enzyme Inhibitors,G1 Phase,Humans,Imidazoles,Lignans,Myocytes, Smooth Muscle,Promoter Regions, Genetic,Protein Kinases,Pyridines,Sequence Deletion,p38 Mitogen-Activated Protein Kinases
– anti atherosclerosis

Natural product agonists of peroxisome proliferator-activated receptor gamma (PPARγ): a review. [25083916]
Agonists of the nuclear receptor PPARγ are therapeutically used to combat hyperglycaemia associated with the metabolic syndrome and type 2 diabetes. In spite of being effective in normalization of blood glucose levels, the currently used PPARγ agonists from the thiazolidinedione type have serious side effects, making the discovery of novel ligands highly relevant. Natural products have proven historically to be a promising pool of structures for drug discovery, and a significant research effort has recently been undertaken to explore the PPARγ-activating potential of a wide range of natural products originating from traditionally used medicinal plants or dietary sources. The majority of identified compounds are selective PPARγ modulators (SPPARMs), transactivating the expression of PPARγ-dependent reporter genes as partial agonists. Those natural PPARγ ligands have different binding modes to the receptor in comparison to the full thiazolidinedione agonists, and on some occasions activate in addition PPARα (e.g. genistein, biochanin A, sargaquinoic acid, sargahydroquinoic acid, resveratrol, amorphastilbol) or the PPARγ-dimer partner retinoid X receptor (RXR; e.g. the neolignans magnolol and honokiol). A number of in vivo studies suggest that some of the natural product activators of PPARγ (e.g. honokiol, amorfrutin 1, amorfrutin B, amorphastilbol) improve metabolic parameters in diabetic animal models, partly with reduced side effects in comparison to full thiazolidinedione agonists. The bioactivity pattern as well as the dietary use of several of the identified active compounds and plant extracts warrants future research regarding their therapeutic potential and the possibility to modulate PPARγ activation by dietary interventions or food supplements.
Mesh:Biological Products,Energy Metabolism,Humans,Models, Molecular,Molecular Structure,PPAR gamma,Protein Binding
Keywords:(−)-Catechin (PubChem CID: 73160),Amorfrutin 1 (PubChem CID: 10132170),Diabetes,Falcarindiol (PubChem CID: 5281148),Honokiol (PubChem CID: 72303),Linolenic acid (PubChem CID: 5280934),Magnolol (PubChem CID: 72300),Natural product,Nuclear receptor,Nutrition,PPAR gamma,Pioglitazone (PubChem CID: 4829),Quercetin (PubChem CID: 5280343),Resveratrol (PubChem CID: 445154),Rosiglitazone (PubChem CID: 77999)
– agonists (binds to and activates) of PPARγ ( a receptor tell cells to store fat)

Discovery and synthesis of novel magnolol derivatives with potent anticancer activity in non-small cell lung cancer. [30006164]
EGFR T790 M accounts for 50% to 60% of cases of non-small-cell lung carcinoma (NSCLC) resistance to the first-generation EGFR tyrosine kinase inhibitors (TKIs). Hence, identifying novel compounds with activity against TKIs resistant is of great value. In this study, twenty honokiol and magnolol derivatives were isolated from the EtOH extract of Magnolia officinalis and the antiproliferative activity was evaluated on HCC827 (19del EGFR mutation), H1975 (L858 R/T790 M EGFR mutation), and H460 (KRAS mutation) cell lines. Among the isolated compounds, piperitylmagnolol (a 3-substituted magnolol derivative) showed the best antiproliferative activity against those three cell lines with the IC values of 15.85, 15.60 and 18.60 μM, respectively, which provided a direction for the structural modification of magnolol. Further structural modification led to the synthesis of thirty-one magnolol derivatives, and compounds A13, C1, and C2 exhibited significant and broad-spectrum antiproliferative activity with the IC values ranging from 4.81 to 13.54 μM, which were approximately 4- and 8-fold more potent than those of honokiol and magnolol, respectively. Moreover, their aqueous solubility was remarkably improved with 12-, 400- and 10 fold greater than those of honokiol and magnolol. Anti-tumor mechanism research revealed that these three compounds were able to induce cell cycle arrest at G0/G1 phase, cause efficient apoptosis in H1975 cells, and also prevent the migration of HUVECs in a dose-dependent manner through Cdk2, Cdk4, Cyclin E, and Cyclin D1 inhibition as well as up-regulation of cleaved-PARP and cleaved-caspase 3 levels. In in vivo antitumor activity, C2 (10, 30 and 100 mg/kg, po) dose-dependently inhibited the tumor growth in H1975 xenograft model with the tumor inhibition rate of 46.3%, 59.3% and 61.2% respectively, suggesting that C2 is a potential oral anticancer agent deserving further investigation.
  • anti lung cancer
Synthesis of magnolol and honokiol derivatives and their effect against hepatocarcinoma cells. [29415009]
The hepatocellular carcinoma is one of the most common malignant tumour with high level of mortality rate due to its rapid progression and high resistance to conventional chemotherapies. Thus, the search for novel therapeutic leads is of global interest. Herein, a small set of derivatives of magnolol 1 and honokiol 2, the main components of Magnolia grandiflora and Magnolia obovata, were evaluated in in vitro assay using tumoral hepatocytes. The pro-drug approach was applied as versatile strategy to the improve bioactivity of the compounds by careful transformation of the hydroxyl groups of magnolol 1 and honokiol 2 in suitable ester derivatives. Compounds 10 and 11 resulted to be more potent than the parental honokiol 2 at concentration down to 1 μM with complete viability of treated fibroblast cells up to concentrations of 80 μM. The combination of a butyrate ester and a bare phenol-OH group in the honokiol structure seemed to play a significant role in the antiproliferative activity identifying an interesting pharmacological clue against hepatocellular carcinoma.
Mesh:Biphenyl Compounds,Carbon-13 Magnetic Resonance Spectroscopy,Carcinoma, Hepatocellular,Cell Line,Cell Line, Tumor,Drug Screening Assays, Antitumor,Humans,Lignans,Liver Neoplasms,Proton Magnetic Resonance Spectroscopy
  • anti liver cancer (hepato/hepto)

Honokiol suppresses proliferation and induces apoptosis via regulation of the miR‑21/PTEN/PI3K/AKT signaling pathway in human osteosarcoma cells. [29393336]
Honokiol (HNK) is a small biphenolic compound, which exerts antineoplastic effects in various types of cancer. However, the mechanism underlying the antitumor effects of HNK in osteosarcoma (OS) cells is not yet fully understood. Emerging evidence has indicated that microRNAs (miRNAs/miRs) serve key roles in numerous pathological processes, including cancer. It has previously been reported that Chinese medicinal herbs harbor anticancer properties via modulating miRNA expression. Therefore, the present study aimed to determine whether HNK could suppress OS cell growth by regulating miRNA expression. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometric analysis were used to evaluate the cell proliferation and apoptosis in human OS cells after treatment with HNK, respectively. The results demonstrated that HNK inhibits proliferation and induces apoptosis of human OS cells in a dose‑dependent manner. Furthermore, HNK‑induced apoptosis was characterized by upregulation of proapoptotic proteins, including cleaved‑caspase‑3, cleaved‑poly (ADP‑ribose) polymerase and B‑cell lymphoma 2 (Bcl‑2)‑associated X protein, and downregulation of the anti‑apoptotic protein Bcl‑2. Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) verified that HNK was able to induce aberrant expression of miRNAs in human OS cells, and miR‑21 was one of the miRNAs that was most significantly downregulated. To further investigate miR‑21 function, the present study validated that HNK reduces miR‑21 levels in a dose‑dependent manner. In addition, restoration of miR‑21 expression abrogated the suppressive effects of HNK on OS cells. Luciferase assay and western blot analysis identified that miR‑21 inhibits the expression of phosphatase and tensin homolog (PTEN) by directly targeting its 3′-UTR. Notably, HNK was able to suppress the phosphoinositide 3‑kinase (PI3K)/protein kinase B (AKT) signaling pathway; however, it was reactivated by miR‑21 overexpression. Taken together, these data indicated that HNK may inhibit proliferation and induce apoptosis of human OS cells by modulating the miR‑21/PTEN/PI3K/AKT signaling pathway. Therefore, miR‑21 may be considered a potential therapeutic target for the treatment of osteosarcoma with HNK.
Mesh:Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Bone Neoplasms,Cell Line, Tumor,Cell Proliferation,Gene Expression Regulation, Neoplastic,Humans,Lignans,MicroRNAs,Osteosarcoma,PTEN Phosphohydrolase,Phosphatidylinositol 3-Kinases,Proto-Oncogene Proteins c-akt,Signal Transduction
– anti bone cancer

SIRT3 activator Honokiol attenuates β-Amyloid by modulating amyloidogenic pathway. [29324783]
Honokiol (poly-phenolic lignan from Magnolia grandiflora) is a Sirtuin-3 (SIRT3) activator which exhibit antioxidant activity and augment mitochondrial functions in several experimental models. Modern evidence suggests the critical role of SIRT3 in the progression of several metabolic and neurodegenerative diseases. Amyloid beta (Aβ), the precursor to extracellular senile plaques, accumulates in the brains of patients with Alzheimer’s disease (AD) and is related to the development of cognitive impairment and neuronal cell death. Aβ is generated from amyloid-β precursor protein (APP) through sequential cleavages, first by β-secretase and then by γ-secretase. Drugs modulating this pathway are believed to be one of the most promising strategies for AD treatment. In the present study, we found that Honokiol significantly enhanced SIRT3 expression, reduced reactive oxygen species generation and lipid peroxidation, enhanced antioxidant activities, and mitochondrial function thereby reducing Aβ and sAPPβ levels in Chinese Hamster Ovarian (CHO) cells (carrying the amyloid precursor protein-APP and Presenilin PS1 mutation). Mechanistic studies revealed that Honokiol affects neither protein levels of APP nor α-secretase activity. In contrast, Honokiol increased the expression of AMPK, CREB, and PGC-1α, thereby inhibiting β-secretase activity leading to reduced Aβ levels. These results suggest that Honokiol is an activator of SIRT3 capable of improving antioxidant activity, mitochondrial energy regulation, while decreasing Aβ, thereby indicating it to be a lead compound for AD drug development.
Mesh:Adenylate Kinase,Amyloid beta-Peptides,Animals,Biphenyl Compounds,CHO Cells,Cricetulus,Cyclic AMP Response Element-Binding Protein,Humans,Lignans,Lipid Peroxidation,Mitochondria,Reactive Oxygen Species,Sirtuin 3
– anti amyloid

Derivatization of honokiol by integrated acetylation and methylation for improved cutaneous delivery and anti-inflammatory potency. [29241737]
A set of honokiol derivatives was synthesized to evaluate skin permeation and bioactivity. The reaction for derivatization included acetylation and methylation. The anti-inflammatory activity against neutrophils and macrophages was examined. The experimental setup for the assessment of cutaneous absorption was the in vitro Franz diffusion assembly. Honokiol and its derivatives significantly downregulated superoxide anion and elastase production in neutrophils, with honokiol showing the greatest inhibition. All derivatives could be completely hydrolyzed to the parent compounds after passing into the skin. The skin deposition of honokiol at an infinite dose (3mM) was 0.33nmol/mg 4′-O-acetylhonokiol (AH), and 2,4′-diacetylhonokiol (DAH) exhibited comparable or less absorption than honokiol. The integrated acetylation and methylation (2-O-acetyl-4′-O-methylhonokiol, AMH) led to a 10.5-fold improvement of absorption compared to honokiol. AMH was advantageous for the targeted cutaneous treatment due to the high skin deposition and minimal penetration across the skin (8.40nmol/cm compared to 93.49nmol/cm for honokiol). The predicted therapeutic index for superoxide and interleukin (IL)-6 inhibition was much higher for topically applied AMH than for the other penetrants tested. The total polarity surface and hydrogen bond acceptor number calculated by molecular modeling were the parameters used to anticipate the cutaneous absorption. Our data suggest that AMH is a potent and safe candidate for cutaneous inflammation therapy.
Mesh:Acetylation,Administration, Cutaneous,Animals,Anti-Inflammatory Agents,Biphenyl Compounds,Cell Survival,Drug Delivery Systems,Female,Humans,Lignans,Methylation,Mice,Mice, Nude,Neutrophils,Skin Absorption
Keywords:Acetylation,Anti-inflammatory activity,Cutaneous absorption,Honokiol,Methylation
– used as a skin applied anti inflammatory in the form of integrated acetylation and methylation (2-O-acetyl-4'-O-methylhonokiol, AMH)

Honokiol induces autophagy and apoptosis of osteosarcoma through PI3K/Akt/mTOR signaling pathway. [29207060]
Honokiol is the main active constituent of Magnolia officinalis. With effective and long‑term pharmacological functions of being antibacterial, anti‑oxidative, anti‑inflammatory, antitumor, anti‑spasmic, anti‑anxiety and anti‑viral, Honokiol is clinically used in the treatment of acute enteritis and chronic gastritis. The aim of the present study was to observe the possible anti‑effects of honokiol on autophagy and apoptosis of osteosarcoma, and to investigate the role of the PI3K/Akt/mTOR signaling pathway in its anticancer effects. MTT assay was used to evaluate cell proliferation and Annexin V‑fluorescein isothiocyanate/propidium iodide staining flow cytometry was used to analyze the apoptotic rate. The authors identified that honokiol could inhibit cell proliferation and induce the apoptotic rate of osteosarcoma cells. The expression level of Bcl‑2‑like protein 4, caspase‑3 and p53 protein expression were induced and cyclin D1 protein expression was suppressed in osteosarcoma cells by honokiol. Autophagy‑associated LC3II protein expression level was promoted, and PI3K, p‑Akt and p‑mTOR protein expression level was suppressed in osteosarcoma cells by honokiol. The present study demonstrated, to the best of the authors’ knowledge, for the first time that honokiol induces autophagy and apoptosis of osteosarcoma cells through the PI3K/Akt/mTOR signaling pathway.
Mesh:Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Bone Neoplasms,Caspase 3,Cell Line, Tumor,Cell Proliferation,Cyclin D1,Humans,Lignans,Osteosarcoma,Phosphatidylinositol 3-Kinases,Proto-Oncogene Proteins c-akt,Signal Transduction,TOR Serine-Threonine Kinases,Tumor Suppressor Protein p53,bcl-2-Associated X Protein
– anti bone cancer

Application of multifunctional targeting epirubicin liposomes in the treatment of non-small-cell lung cancer. [29066893]
Chemotherapy for aggressive non-small-cell lung cancer (NSCLC) usually results in a poor prognosis due to tumor metastasis, vasculogenic mimicry (VM) channels, limited killing of tumor cells, and severe systemic toxicity. Herein, we developed a kind of multifunctional targeting epirubicin liposomes to enhance antitumor efficacy for NSCLC. In the liposomes, octreotide was modified on liposomal surface for obtaining a receptor-mediated targeting effect, and honokiol was incorporated into the lipid bilayer for inhibiting tumor metastasis and eliminating VM channels. In vitro cellular assays showed that multifunctional targeting epirubicin liposomes not only exhibited the strongest cytotoxic effect on Lewis lung tumor cells but also showed the most efficient inhibition on VM channels. Action mechanism studies showed that multifunctional targeting epirubicin liposomes could downregulate PI3K, MMP-2, MMP-9, VE-Cadherin, and FAK and activate apoptotic enzyme caspase 3. In vivo results exhibited that multifunctional targeting epirubicin liposomes could accumulate selectively in tumor site and display an obvious antitumor efficacy. In addition, no significant toxicity of blood system and major organs was observed at a test dose. Therefore, multifunctional targeting epirubicin liposomes may provide a safe and efficient therapy strategy for NSCLC.
Mesh:Animals,Antibiotics, Antineoplastic,Antigens, CD,Cadherins,Carcinoma, Non-Small-Cell Lung,Caspase 3,Cell Line, Tumor,Epirubicin,Humans,Liposomes,Lung Neoplasms,Matrix Metalloproteinase 2,Matrix Metalloproteinase 9,Mice, Inbred BALB C,Phosphatidylinositol 3-Kinases,Xenograft Model Antitumor Assays
Keywords:chemotherapy,honokiol,octreotide,targeting drug delivery,tumor metastasis,vasculogenic mimicry
– anti lung cancer

Honokiol triggers receptor‑interacting protein kinase 3‑mediated cell death of neuroblastoma cells by upregulating reactive oxygen species. [28983589]
Neuroblastoma is the most common form of childhood extracranial tumor and almost half of neuroblastoma cases occur in infants under two years old. Neuroblastoma accounts for ~6‑10% of childhood cancers and 15% of cancer‑associated childhood mortality. However, an effective treatment remains to be developed. Honokiol exhibits long‑lasting central muscle relaxation, anti‑inflammatory, antibacterial, antimicrobial, antiulcer, antioxidation, antiaging and antitumor effects. Honokiol has been previously demonstrated to kill neuroblastoma cells, however, the underlying mechanism of action remains unclear. The present study reports that honokiol inhibits the growth of neuroblastoma cells via upregulation of reactive oxygen species (ROS). MTT assays demonstrated that treatment of Neuro‑2a neuroblastoma cells with honokiol resulted in time‑ and dose‑dependent inhibition of cell proliferation, which was associated with upregulation of the protein expression of receptor‑interacting protein kinase 3 (RIP3), as demonstrated by western blot analysis. Furthermore, knockdown of RIP3 by small interfering RNA, or pharmacological inhibition of RIP3 by the RIP3 specific inhibitor necrosulfonamide, reversed honokiol‑induced loss of cell viability in Neuro‑2a cells. Importantly, honokiol significantly increased the intracellular ROS levels as determined by a 2′,7’‑dichlorofluorescin diacetate assay, while ROS scavenger N‑acetyl cysteine significantly prevented the induction of ROS and RIP3 by honokiol. The results of the present study indicate that honokiol may suppress the growth of neuroblastoma Neuro‑2a cells, at least partially, through ROS‑mediated upregulation of RIP3.
Mesh:Acetylcysteine,Apoptosis,Biphenyl Compounds,Cell Line, Tumor,Cell Proliferation,Cell Survival,Gene Silencing,Humans,Lignans,Neuroblastoma,RNA, Small Interfering,Reactive Oxygen Species,Receptor-Interacting Protein Serine-Threonine Kinases,Time Factors,Up-Regulation
– anti nerve cancer

Honokiol induces superoxide production by targeting mitochondrial respiratory chain complex I in Candida albicans. [28854218]
Honokiol, a compound extracted from Magnolia officinalis, has antifungal activities by inducing mitochondrial dysfunction and triggering apoptosis in Candida albicans. However, the mechanism of honokiol-induced oxidative stress is poorly understood. The present investigation was designed to determine the specific mitochondrial reactive oxygen species (ROS)-generation component.
-   We found that honokiol induced mitochondrial ROS accumulation, mainly superoxide anions (O2•-) measured by fluorescent staining method. The mitochondrial respiratory chain complex I (C I) inhibitor rotenone completely blocked O2•- production and provided the protection from the killing action of honokiol. Moreover, respiratory activity and the C I enzyme activity was significantly reduced after honokiol treatment. The differential gene-expression profile also showed that genes involved in oxidoreductase activity, electron transport, and oxidative phosphorylation were upregulated.
-   The present work shows that honokiol may bind to mitochondrial respiratory chain C I, leading to mitochondrial dysfunction, accompanied by increased cellular superoxide anion and oxidative stress.
-   This work not only provides insights on the mechanism by which honokiol interferes with fungal cell, demonstrating previously unknown effects on mitochondrial physiology, but also raises a note of caution on the use of M. officinalis as a Chinese medicine due to the toxic for mitochondria and suggests the possibility of using honokiol as chemosensitizer.
Mesh:Antifungal Agents,Biphenyl Compounds,Candida albicans,Candidiasis,Electron Transport Complex I,Fungal Proteins,Gene Expression Regulation, Fungal,Humans,Lignans,Magnolia,Oxidative Stress,Superoxides
  • anti candida
Honokiol improved chondrogenesis and suppressed inflammation in human umbilical cord derived mesenchymal stem cells via blocking nuclear factor-κB pathway. [28851291]
Cartilage degradation is the significant pathological process in osteoarthritis (OA). Inflammatory cytokines, such as interleukin-1β (IL-1β), activate various downstream mediators contributing to OA pathology. Recently, stem cell-based cartilage repair emerges as a potential therapeutic strategy that being widely studied, whereas, the outcome is still far from clinical application. In this study, we focused on an anti-inflammatory agent, honokiol, which is isolated from an herb, investigated the potential effects on human umbilical cord derived mesenchymal stem cells (hUC-MSCs) in IL-1β stimulation.
-   Second passage hUC-MSCs were cultured for multi-differentiation. Flow cytometry, qRT-PCR, von Kossa stain, alcian blue stain and oil red O stain were used for characterization and multi-differentiation determination. Honokiol (5, 10, 25, 50 μM) and IL-1β (10 ng/ml) were applied in hUC-MSCs during chondrogenesis. Analysis was performed by MTT, cell apoptosis evaluation, ELISA assay, qRT-PCR and western blot.
-   hUC-MSC was positive for CD73, CD90 and CD105, but lack of CD34 and CD45. Remarkable osteogenesis, chondrogenesis and adipogenesis were detected in hUC-MSCs. IL-1β enhanced cell apoptosis and necrosis and activated the expression of caspase-3, cyclooxygenase-2 (COX-2), interleukin-6 (IL-6) and matrix metalloproteinase (MMP)-1, -9, 13 in hUC-MSCs. Moreover, the expression of SRY-related high-mobility group box 9 (SOX-9), aggrecan and col2α1 was suppressed. Honokiol relieved these negative impacts induced by IL-1β and suppressed Nuclear factor-κB (NF-κB) pathway by downregulating expression of p-IKKα/β, p-IκBα and p-p65 in dose-dependent and time-dependent manner.
-   Honokiol improved cell survival and chondrogenesis of hUC-MSCs and inhibited IL-1β-induced inflammatory response, which suggested that combination of anti-inflammation and stem cell can be a novel strategy for better cartilage repair.
Mesh:Anti-Inflammatory Agents,Apoptosis,Biphenyl Compounds,Caspase 3,Cell Differentiation,Cell Survival,Cells, Cultured,Chondrogenesis,Collagenases,Cyclooxygenase 2,Gene Expression Regulation,Humans,Inflammation,Interleukin-6,Lignans,Mesenchymal Stromal Cells,NF-kappa B,Signal Transduction
Keywords:Cartilage repair,Honokiol,Interleukin-1β,Mesenchymal stem cell,Osteoarthritis

  • chondrogenesis (cartilage creation) in stem cells

BMP7 mediates the anticancer effect of honokiol by upregulating p53 in HCT116 cells. [28731124]
Colorectal cancer (CRC) is the second leading cause of cancer death. Hence, there is a great need to explore new efficacious drugs for the treatment of CRC. Honokiol (HNK), a natural product extracted from magnolia bark, processes various biological activities, including anticancer. In this study, we introduced cell viability assay, western blotting, real-time PCR and immunofluorescent staining to determine the anticancer effect of HNK, and the possible mechanism underlying this biological process. We found that HNK can inhibit the proliferation and induce apoptosis in HCT116 cells in a concentration- and time-dependent manner. HNK activates p53 in HCT116 and other colon cancer cells. Exogenous p53 potentiates the anticancer of HNK, while p53 inhibitor decreases this effect of HNK. Moreover, HNK upregulates the expression of bone morphogenetic protein 7 (BMP7) in colon cancer cells; Exogenous BMP7 enhances the anticancer activity of HNK and BMP7 specific antibody reduces this effect of HNK. For mechanism, we found that HNK cannot increase the level of Smad1/5/8; Exogenous BMP7 potentiates the HNK-induced activation of p53. On the contrary, BMP7 specific antibody inhibits the HNK-induced activation of p53 in colon cancer cells and partly decreases the total level of p53. Our findings suggested that HNK may be a promising anticancer drug for CRC; activation of p53 plays an important role in the anticancer activity of HNK, which may be initialized partly by the HNK-induced upregulation of BMP7.
Mesh:Apoptosis,Biphenyl Compounds,Bone Morphogenetic Protein 7,Cell Proliferation,Cell Survival,Colonic Neoplasms,Gene Expression Regulation, Neoplastic,HCT116 Cells,Humans,Lignans,Signal Transduction,Smad Proteins,Tumor Suppressor Protein p53
– anti Colorectal cancer

Liposomal honokiol induced lysosomal degradation of Hsp90 client proteins and protective autophagy in both gefitinib-sensitive and gefitinib-resistant NSCLC cells. [28689115]
Honokiol (HK), a natural chemical isolated from Mangnolia officinalis, has shown antitumorigenic activities when used to treat a variety of tumor cell lines. The mechanism of honokiol activity when used to treat gefitinib-sensitive and gefitinib-resistant non-small cell lung cancer (NSCLC) requires elucidation. Here, the presence of liposomal honokiol (LHK) induced apoptotic and antitumor activities in four xenograft models generated using NSCLC cell lines such as HCC827 (gefitinib-sensitive) and H1975 (gefitinib-resistant). Mechanistic studies revealed that LHK inhibited the Akt and Erk1/2, both EGFR signaling cascades effectors, by promoting degradation of HSP90 client proteins (HCP), including wild-type or mutant EGFR, Akt and C-Raf. Molecular biology assays showed that LHK induced HCP degradation through a lysosomal pathway, rather than the canonical proteasome protein degradation pathway. As a result of misfolded protein accumulation, LHK induced endoplasmic reticulum (ER) stress and autophagy. Inhibition of ER stress (with 4-phenylbutyrate) or autophagy (with small interfering RNA) reduced LHK-induced HCP degradations. Additionally, LHK induced autophagy showed a protective role for cancer cell as inhibition of autophagy in vitro and in vivo by autophagosome degradation inhibitors could promote the anticancer activity of LHK. LHK has been approved by the China Food and Drug Administration for first-in-human clinical trials in NSCLC. The current study will guide the design of future LHK clinical trials.
Mesh:Animals,Antineoplastic Agents,Autophagy,Biphenyl Compounds,Carcinoma, Non-Small-Cell Lung,Cell Line, Tumor,Drug Resistance, Neoplasm,Female,HSP90 Heat-Shock Proteins,Humans,Lignans,Lung Neoplasms,Mice, Inbred BALB C,Mice, Nude,Quinazolines,Signal Transduction
– autophagy

Activation of tumor suppressor LKB1 by honokiol abrogates cancer stem-like phenotype in breast cancer via inhibition of oncogenic Stat3. [28581518]
Tumor suppressor and upstream master kinase Liver kinase B1 (LKB1) plays a significant role in suppressing cancer growth and metastatic progression. We show that low-LKB1 expression significantly correlates with poor survival outcome in breast cancer. In line with this observation, loss-of-LKB1 rendered breast cancer cells highly migratory and invasive, attaining cancer stem cell-like phenotype. Accordingly, LKB1-null breast cancer cells exhibited an increased ability to form mammospheres and elevated expression of pluripotency-factors (Oct4, Nanog and Sox2), properties also observed in spontaneous tumors in Lkb1 mice. Conversely, LKB1-overexpression in LKB1-null cells abrogated invasion, migration and mammosphere-formation. Honokiol (HNK), a bioactive molecule from Magnolia grandiflora increased LKB1 expression, inhibited individual cell-motility and abrogated the stem-like phenotype of breast cancer cells by reducing the formation of mammosphere, expression of pluripotency-factors and aldehyde dehydrogenase activity. LKB1, and its substrate, AMP-dependent protein kinase (AMPK) are important for HNK-mediated inhibition of pluripotency factors since LKB1-silencing and AMPK-inhibition abrogated, while LKB1-overexpression and AMPK-activation potentiated HNK’s effects. Mechanistic studies showed that HNK inhibited Stat3-phosphorylation/activation in an LKB1-dependent manner, preventing its recruitment to canonical binding-sites in the promoters of Nanog, Oct4 and Sox2. Thus, inhibition of the coactivation-function of Stat3 resulted in suppression of expression of pluripotency factors. Further, we showed that HNK inhibited breast tumorigenesis in mice in an LKB1-dependent manner. Molecular analyses of HNK-treated xenografts corroborated our in vitro mechanistic findings. Collectively, these results present the first in vitro and in vivo evidence to support crosstalk between LKB1, Stat3 and pluripotency factors in breast cancer and effective anticancer modulation of this axis with HNK treatment.
Mesh:Animals,Biphenyl Compounds,Breast Neoplasms,Cell Line, Tumor,Cell Movement,Cell Transformation, Neoplastic,Female,Humans,Lignans,Mice,Neoplastic Stem Cells,Protein-Serine-Threonine Kinases,STAT3 Transcription Factor,Xenograft Model Antitumor Assays
– breast cancer prevention

Honokiol-loaded polymeric nanoparticles: an active targeting drug delivery system for the treatment of nasopharyngeal carcinoma. [28368206]
The purpose of this study was to develop a novel drug delivery system for a sustained and targeted delivery of honokiol (HK) to the nasopharyngeal carcinoma (NPC) HNE-1 cell lines, since the folate receptor (FR) is over-expressed on their surface. Emulsion solvent evaporation was used to develop the active targeting nanoparticles-loaded HK (ATNH) using copolymerpoly (ɛ-caprolactone)-poly (ethyleneglycol)-poly (ɛ-caprolactone) (PCEC), which was modified with folate (FA) by introducing Polythylenimine (PEI). ATNH characterization, including particle size distribution, morphology, drug loading, encapsulation efficiency and drug release, was performed. Transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR) were employed to evaluate the shape and construction, respectively. MTT assay, cell uptake study and apoptosis test were assayed to detect the antitumor properties and targeting uptake by HNE-1 cells in vitro. Cell-cycle redistribution, F-FDG PET/CT and immunohistochemistry were performed in vivo. The ATNH we developed were successfully synthesized and showed a suitable size distribution, high encapsulation efficiency, gradual release, and targeting uptake by the cells in vitro. Moreover, ATNH significantly inhibited tumor growth, metabolism, proliferation, micro-vessel generation, and caused cell-cycle arrest at G phase. Thus, these nanoparticles we developed might represent a novel formulation for HK delivery and a promising potential therapy in the treatment of cancer.
Mesh:Biphenyl Compounds,Carcinoma,Cell Line, Tumor,Drug Delivery Systems,Humans,Lignans,Nanoparticles,Nasopharyngeal Neoplasms,Particle Size,Polyethylene Glycols,Positron Emission Tomography Computed Tomography
Keywords:Honokiol,NPC,active targeting,folate,nanoparticles
– anti nasopharyngeal carcinoma, topical application

Honokiol nanomicellar formulation produced increased oral bioavailability and anticancer effects in triple negative breast cancer (TNBC). [28249200]
Triple negative breast cancer (TNBC), owing to its aggressive behavior and toxicity associated with available chemotherapy; currently no suitable therapy is available. Honokiol (HNK) is a promising anticancer drug but has poor bioavailability. In the current study, we evaluated the anticancer effects of an oral Honokiol nanomicellar (NM) formulation (size range of 20-40nm) in vitro against various TNBC cells lines. Cytotoxicity, clonogenic and wound healing assays demonstrated the promising anticancer effects. In vitro Caco-2 permeability studies suggested increased absorption of Honokiol. Compared to HNK-FD, nanomicellar formulations resulted in significant increase in the oral bioavailability. C (4.06 and 3.60-fold) and AUC (6.26 and 5.83-fold) were significantly increased in comparison to oral 40 and 80mg/kg free drug respectively. Further, anticancer effects of these formulations were studied in BALB/c nude mice transplanted with orthotopic MDA-MB-231 cell induced xenografts. After 4 weeks of daily administration of HNK-NM formulation, significant reduction in the tumor volumes and weights compared to free drug (p<0.001) treated groups was observed. Surprisingly, in some of the animals (25%), the treatment resulted in complete eradication of tumors. Increased apoptosis and antiangiogenic effect was observed in HNK-NM groups compared to free drug and untreated control animals. This is the first report demonstrating that HNK-FD possesses anticancer effects against TNBC.
Mesh:Administration, Oral,Animals,Antineoplastic Agents,Apoptosis,Biological Availability,Biphenyl Compounds,Caco-2 Cells,Cell Line, Tumor,Cell Proliferation,Dose-Response Relationship, Drug,Female,Humans,Lignans,Male,Mammary Neoplasms, Experimental,Mice,Mice, Inbred BALB C,Mice, Inbred C57BL,Mice, Nude,Micelles,Nanoparticles,Particle Size,Structure-Activity Relationship,Surface Properties,Triple Negative Breast Neoplasms
Keywords:Anticancer,Bioavailability,Honokiol,Nanomicellar formulation,TNBC
– anti breast cancer

Honokiol protects skin cells against inflammation, collagenolysis, apoptosis, and senescence caused by cigarette smoke damage. [28229451]
Pollution, especially cigarette smoke, is a major cause of skin damage.
-   To assess the effects of the small molecule polyphenol, honokiol, on reversing cigarette smoke-induced damage in vitro to relevant skin cells.
-   Keratinocytes (HaCat) cultures were exposed to cigarette smoke and, after 48 hours, IL-1α and IL-8 were measured in cell supernatants. Moreover, TIMP-2 production, apoptosis rate, and senescence β-galactosidase expression were evaluated in primary human foreskin fibroblasts (HFF-1) cultures.
-   Honokiol at 10 μm reduced IL-1α production by 3.4 folds (P < 0.05) and at 10 and 20 μm reduced IL-8 by 23.9% and 53.1% (P < 0.001), respectively, in HaCat keratinocytes. In HFF-1, honokiol restored TIMP-2 production by 96.9% and 91.9% (P < 0.001), respectively, at 10 and 20 μm, as well as reduced apoptosis by 47.1% (P < 0.001) and 41.3% (P < 0.01), respectively. Finally, honokiol reduced senescence-associated β-galactosidase expression in HFF-1.
-   Honokiol protects both HFF-1 and HaCat against cigarette smoke-induced inflammation, collagenolysis, apoptosis, and senescence.
Mesh:Antioxidants,Apoptosis,Biphenyl Compounds,Cells, Cultured,Cellular Senescence,Fibroblasts,Humans,Inflammation,Interleukin-1alpha,Interleukin-8,Lignans,Tissue Inhibitor of Metalloproteinase-2,Tobacco Smoke Pollution,beta-Galactosidase
  • Honokiol protects skin cells against inflammation, collagenolysis, apoptosis, and senescence caused by cigarette smoke damage. [28229451]

Antineoplastic Effects of Honokiol on Melanoma. [28194418]
Honokiol, a plant lignan has been shown to have antineoplastic effects against nonmelanoma skin cancer developments in mice. In this study, antineoplastic effects of honokiol were investigated in malignant melanoma models. In vitro effects of honokiol treatment on SKMEL-2 and UACC-62 melanoma cells were evaluated by measuring the cell viability, proliferation, apoptosis, cell cycle analysis, and expressions of various proteins associated with cell cycle progression and apoptosis. For the in vivo study, male nude mice inoculated with SKMEL-2 or UACC-62 cells received injections of sesame oil or honokiol for two to seven weeks. In vitro honokiol treatment caused significant decrease in cell viability, proliferation, cell cycle arrest, increased apoptosis, and modulation of apoptotic and cell cycle regulatory proteins. Honokiol caused an accumulation of cells in the G2/M phase of the cell cycle in SKMEL-2 and G0/G1 phase in UACC-62 cells. An elevated level of caspases and PARP were observed in both cell lines treated with honokiol. A decrease in the expression of various cell cycle regulatory proteins was also observed in honokiol treated cells. Honokiol caused a significant reduction of tumor growth in SKMEL-2 and UACC-62 melanoma xenografts. These findings suggest that honokiol is a good candidate for further studies as a possible treatment for malignant melanoma.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Cell Cycle,Cell Line, Tumor,Cell Survival,Gene Expression Regulation, Neoplastic,Humans,Lignans,Male,Melanoma,Mice,Mice, Nude,Neoplasm Proteins,Xenograft Model Antitumor Assays
– anti melanoma

Honokiol induces proteasomal degradation of AML1-ETO oncoprotein via increasing ubiquitin conjugase UbcH8 expression in leukemia. [28043811]
AML1-ETO is the most common oncoprotein leading to acute myeloid leukemia (AML), in which 5-year survival rate is only about 30%. However, currently there are no specific therapies for AML patients with AML1-ETO. Here, we report that AML1-ETO protein is rapidly degraded by Honokiol (HNK), a natural phenolic compound isolated from the plant Magnolia officinalis. HNK induced the degradation of AML1-ETO in a concentration- and time-dependent manner in leukemic cell lines and primary AML blasts with t(8;21) translocation. Mechanistically, HNK obviously increased the expression of UbcH8, an E2-conjugase for the degradation of AML1-ETO, through triggering accumulation of acetylated histones in the promoter region of UbcH8. Knockdown of UbcH8 by small hairpin RNAs (shRNAs) prevented HNK-induced degradation of AML-ETO, suggesting that UbcH8 plays a critical role in the degradation of AML1-ETO. HNK inhibited cell proliferation and induced apoptotic death without activation of caspase-3, which was reported to cleave and degrade AML1-ETO protein. Thus, HNK-induced degradation of AML1-ETO is independent of activation of caspase-3. Finally, HNK reduced the angiogenesis and migration in Kasumi-1-injected zebrafish, decreased xenograft tumor size in a xenograft leukemia mouse model, and prolonged the survival time in mouse C1498 AML model. Collectively, HNK might be a potential treatment for t(8;21) leukemia by targeting AML1-ETO oncoprotein.
Mesh:Acetylation,Animals,Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Cell Line, Tumor,Core Binding Factor Alpha 2 Subunit,Embryo, Nonmammalian,Humans,Leukemia, Myeloid, Acute,Lignans,Male,Mice,Mice, Nude,Neoplasm Transplantation,Neovascularization, Physiologic,Oncogene Proteins, Fusion,Promoter Regions, Genetic,Proteasome Endopeptidase Complex,RUNX1 Translocation Partner 1 Protein,Ubiquitin-Conjugating Enzymes,Zebrafish
Keywords:AML1-ETO,Honokiol,Honokiol (PubChem CID 72303),Trichostatin A (PubChem CID 444732),UbcH8
– anti leukemia

Honokiol, a potential therapeutic agent, induces cell cycle arrest and program cell death in vitro and in vivo in human thyroid cancer cells. [27940017]
Thyroid cancer is the most common endocrine malignancy, the global incidence rate of which is rapidly rising. Surgery and radioiodine therapies are common and effective treatments only for nonmetastasized primary tumors. Therefore, effective treatment modalities are imperative for patients with radioiodine-resistant thyroid cancer. Honokiol, a biophenolic compound derived from Magnolia spp., has been shown have diverse biological and pharmacological activities, including anti-inflammatory, antioxidative, antiangiogenic, and anticancer properties. In the present study, three human thyroid cancer cell lines, namely anaplastic, follicular, and poorly differentiated thyroid cancer cells, were used to evaluate the chemotherapeutic activity of honokiol. Cell viability, cell cycle, apoptosis, and autophagy induction were determined through flow cytometry and western blot analysis. We found that honokiol treatment can suppress cell growth, induce cell cycle arrest, and enhance the induction of caspase-dependent apoptosis and autophagy in cancer cells. Moreover, honokiol treatment modulated signaling pathways including Akt/mTOR, ERK, JNK, and p38 in the studied cells. In addition, the antitumorigenic activity of honokiol was also confirmed in vitro and in vivo. Our data provide evidence that honokiol has a unique application in chemotherapy for human thyroid cancers.
Mesh:Antineoplastic Agents, Phytogenic,Apoptosis,Autophagy,Biphenyl Compounds,Cell Cycle Checkpoints,Cell Line, Tumor,Cell Proliferation,Cell Survival,Humans,Lignans,Signal Transduction,Thyroid Neoplasms
Keywords:Anti-cancer,Apoptosis,Autophagy,Honokiol,Thyroid cancer
– anti thyroid cancer

Non-toxic dose of liposomal honokiol suppresses metastasis of hepatocellular carcinoma through destabilizing EGFR and inhibiting the downstream pathways. [27906672]
At present, there is no specific anti-metastasis drug in HCC treatment. Drugs used for primary HCC tumors and tumor metastasis are very similar, among which cytotoxic drugs are prevalent, such as cisplatin, doxorubicin and 5-FU. The EGFR pathway plays an important role in promoting hepatocellular carcinoma (HCC) metastasis. Hence, development of non-toxic anti-metastasis drugs, such as EGFR or downstream pathways inhibitors, is of great importance. In our present study, we found non-toxic dose of liposomal honokiol (LH) could inhibit the HCC metastasis by destabilizing EGFR and inhibiting the downstream pathways. Non-toxic dose of LH significantly inhibited the motility, migration and lamellipodia formation of HepG2 cells in vitro and decreased extravasation of HepG2 cells in a novel metastasis model of transgenic zebrafish. In two lung metastasis models (HepG2 and B16F10) and a spontaneous metastasis model of HepG2 cells, LH remarkably inhibited pulmonary metastasis and regional lymph nodes metastasis without obvious toxicity. Further study showed that destabilizing EGFR and inhibiting the downstream pathways were the main mechanisms of non-toxic dose of LH on metastasis inhibition. Our results provide the preclinical rationale and the underlying mechanisms of LH to suppress HCC metastasis, implicating LH as a potential therapeutic agent to block HCC metastasis without severe side effects.
Mesh:Animals,Antineoplastic Agents,Apoptosis,Biphenyl Compounds,Carcinoma, Hepatocellular,Cell Cycle,Cell Line, Tumor,Cell Movement,Cell Proliferation,Disease Models, Animal,Female,Hep G2 Cells,Heterografts,Humans,Lignans,Liver Neoplasms,MAP Kinase Signaling System,Matrix Metalloproteinase 2,Matrix Metalloproteinase 9,Melanoma, Experimental,Mice,Neoplasm Metastasis,Neoplasm Staging,Protein Stability,Receptor, Epidermal Growth Factor,Signal Transduction,Zebrafish,cdc42 GTP-Binding Protein,rac1 GTP-Binding Protein
Keywords:EGFR,hepatocellular carcinoma,liposomal honokiol,metastasis,motility
– anti liver cancer

Honokiol Decreases Lung Cancer Metastasis through Inhibition of the STAT3 Signaling Pathway. [27849557]
Lung cancer is the leading cause of cancer death in the United States. Metastasis to lymph nodes and distal organs, especially brain, leads to severe complications and death. Preventing lung cancer development and metastases is an important strategy to reduce lung cancer mortality. Honokiol (HNK), a natural compound present in the extracts of magnolia bark, has a favorable bioavailability profile and recently has been shown to readily cross the blood-brain barrier. In the current study, we evaluated the antimetastatic effects of HNK in both the lymph node and brain mouse models of lung tumor metastasis. We tested the efficacy of HNK in preventing 18 H2030-BrM3 cell (brain-seeking human lung tumor cells) migration to lymph node or brain. In an orthotopic mouse model, HNK significantly decreased lung tumor growth compared with the vehicle control group. HNK also significantly reduced the incidence of lymph node metastasis and the weight of mediastinal lymph nodes. In a brain metastasis model, HNK inhibits metastasis of lung cancer cells to the brain to approximately one third of that observed in control mice. We analyzed HNK’s mechanism of action, which indicated that its effect is mediated primarily by inhibiting the STAT3 pathway. HNK specifically inhibits STAT3 phosphorylation irrespective of the mutation status of EGFR, and knockdown of STAT3 abrogated both the antiproliferative and the antimetastatic effects of HNK. These observations suggest that HNK could provide novel chemopreventive or therapeutic options for preventing both lung tumor progression and lung cancer metastasis. Cancer Prev Res; 10(2); 133-41. ©2016 AACR.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Brain Neoplasms,Cell Line, Tumor,Cell Movement,Cell Proliferation,Female,Humans,Lignans,Lung Neoplasms,Lymphatic Metastasis,Mice,Mice, Inbred NOD,Mice, SCID,STAT3 Transcription Factor,Signal Transduction,Xenograft Model Antitumor Assays
– anti lung cancer

Honokiol suppresses pancreatic tumor growth, metastasis and desmoplasia by interfering with tumor-stromal cross-talk. [27609457]
The poor clinical outcome of pancreatic cancer (PC) is largely attributed to its aggressive nature and refractoriness to currently available therapeutic modalities. We previously reported antitumor efficacy of honokiol (HNK), a phytochemical isolated from various parts of Magnolia plant, against PC cells in short-term in vitro growth assays. Here, we report that HNK reduces plating efficiency and anchorage-independent growth of PC cells and suppresses their migration and invasiveness. Furthermore, significant inhibition of pancreatic tumor growth by HNK is observed in orthotopic mouse model along with complete-blockage of distant metastases. Histological examination suggests reduced desmoplasia in tumors from HNK-treated mice, later confirmed by immunohistochemical analyses of myofibroblast and extracellular matrix marker proteins (α-SMA and collagen I, respectively). At the molecular level, HNK treatment leads to decreased expression of sonic hedgehog (SHH) and CXCR4, two established mediators of bidirectional tumor-stromal cross-talk, both in vitro and in vivo . We also show that the conditioned media (CM) from HNK-treated PC cells have little growth-inducing effect on pancreatic stellate cells (PSCs) that could be regained by the addition of exogenous recombinant SHH. Moreover, pretreatment of CM of vehicle-treated PC cells with SHH-neutralizing antibody abolishes their growth-inducing potential on PSCs. Likewise, HNK-treated PC cells respond poorly to CM from PSCs due to decreased CXCR4 expression. Lastly, we show that the transfection of PC cells with constitutively active IKKβ mutant reverses the suppressive effect of HNK on nuclear factor-kappaB activation and partially restores CXCR4 and SHH expression. Taken together, these findings suggest that HNK interferes with tumor-stromal cross-talk via downregulation of CXCR4 and SHH and decreases pancreatic tumor growth and metastasis.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Cell Communication,Cell Line, Tumor,Down-Regulation,Female,Gene Expression,Hedgehog Proteins,Humans,Lignans,Liver Neoplasms, Experimental,Lung Neoplasms,Mice,Pancreatic Neoplasms,Receptors, CXCR4,Tumor Microenvironment,Xenograft Model Antitumor Assays
– anti pancreatic cancer

Honokiol inhibits EMT-mediated motility and migration of human non-small cell lung cancer cells in vitro by targeting c-FLIP. [27593221]
Honokiol (HNK) is a natural compound isolated from the magnolia plant with numerous pharmacological activities, including inhibiting epithelial-mesenchymal transition (EMT), which has been proposed as an attractive target for anti-tumor drugs to prevent tumor migration. In this study we investigated the effects of HNK on EMT in human NSCLC cells in vitro and the related signaling mechanisms.
-   TNF-α (25 ng/mL) in combination with TGF-β1 (5 ng/mL) was used to stimulate EMT of human NSCLC A549 and H460 cells. Cell proliferation was analyzed using a sulforhodamine B assay. A wound-healing assay and a transwell assay were performed to examine cell motility. Western blotting was used to detect the expression levels of relevant proteins. siRNAs were used to knock down the gene expression of c-FLIP and N-cadherin. Stable overexpression of c-FLIP L (H157-FLIP L) or Lac Z (H157-Lac Z) was also performed.
-   Treatment with TNF-α+TGF-β1 significantly enhanced the migration of A549 and H460 cells, increased c-FLIP, N-cadherin (a mesenchymal marker), snail (a transcriptional modulator) and p-Smad2/3 expression, and decreased IκB levels in the cells; these changes were abrogated by co-treatment with HNK (30 μmol/L). Further studies demonstrated that expression level of c-FLIP was highly correlated with the movement and migration of NSCLC cells, and the downstream effectors of c-FLIP signaling were NF-κB signaling and N-cadherin/snail signaling, while Smad signaling might lie upstream of c-FLIP.
-   HNK inhibits EMT-mediated motility and migration of human NSCLC cells in vitro by targeting c-FLIP, which can be utilized as a promising target for cancer therapy, while HNK may become a potential anti-metastasis drug or lead compound.
Mesh:Animals,Antineoplastic Agents,Apoptosis,Autophagy,Biphenyl Compounds,CASP8 and FADD-Like Apoptosis Regulating Protein,Carcinoma, Non-Small-Cell Lung,Cell Line, Tumor,Cell Movement,Epithelial-Mesenchymal Transition,Humans,Lignans,Lung Neoplasms
  • anti lung cancer
Anticancer activity of Honokiol against lymphoid malignant cells via activation of ROS-JNK and attenuation of Nrf2 and NF-κB. [27569089]
To evaluate the effect of Honokiol (HK) in the ROS-JNK pro-apoptotic pathway and NF-κB, Nrf2 anti-apoptotic pathways, in order to seek a possible explanation for its anticancer efficacy.
-   The Raji and Molt4 cell lines were utilized for the determination of anticancer activity against lymphoid malignant cells. BALB/C nude mice, weighing 18-20g each and aged 4-5 weeks, were procured from the central animal house facility. For establishing non-Hodgkin lymphoma in BALB/C, the nude mice were subcutaneously administered 1×10(7) Raji cells, suspended in 0.2 mL sterile PBS on the back. The mice were then randomly divided into 3 groups (6 mice in each group). HK cytotoxicity was determined using the colorimetric MTT assay.
-   In colorimetry-based MTT assay, the cytotoxicity of HK was determined at different time intervals, in lymphoid malignant Raji and Molt4 cell lines. HK exhibited prominent cytotoxicity against Raji cell lines with IC50 of 0.092 ± 0.021 μM. In Molt4 cells, the administration of HK caused significant cytotoxicity with IC50 of 0.521 ± 0.115 μM. The treatment of HK caused significant increase in the activity of reactive oxygen species (ROS) in Raji cells at various time intervals. Moreover, the level of NF-κB was significantly reduced in the presence of HK, which could be easily understood by a decreased level of p-65. Furthermore, in the presence of ROS inhibitor NAC (10mM) for 24 hrs, the JNK pathway was markedly activated, together with inhibition of NF-κB activity and a reduced level of Nrf2 expression. To further confirm the in vitro results by in vivo activity, HK was observed to inhibit the proliferation of Raji cells in vivo, which might be attributable to its inhibitory effect against the progression of the tumor (p<0.05).
-   The present study suggests that HK causes considerable induction of apoptosis in lymphoid malignant cells, both in vitro and in vivo, whereas the generation of ROS might serve as an underlying mechanism for inducing apoptosis.
Mesh:Animals,Antineoplastic Agents,Apoptosis,Biphenyl Compounds,Cell Line, Tumor,Humans,Lignans,Lymphoma,MAP Kinase Signaling System,Mice,Mice, Inbred BALB C,NF-E2-Related Factor 2,NF-kappa B,Reactive Oxygen Species,Xenograft Model Antitumor Assays
  • anti lymph node cancer
[Inhibition of methicillin-resistant Staphylococcus aureus biofilm by honokiol]. [29738196]
To study the inhibition of methicillin-resistant Staphylococcus aureas (MRSA) biofilm by honokiol.
-   We used triphenyl tetrazolium chloride method to evaluate the inhibition of biofilm formation and mature by honokiol. We used congo red agar and spectrophotometer to detect the influence of honokiol on polysaccharide intercellular adhesion formation and extracellular DNA release. RT-PCR analysis was used to determine the effect of honokiol on expression of icaA, cidA and agrA.
-   Honokiol showed strong antimicrobial activity both on biofilm formation and mature biofilm of MRSA 41573. Minimum inhibitory concentration was 10 μg/mL for biofilm formation and 50 μg/mL for mature biofilm. Minimum bactericidal concentration was 20 μg/mL for biofilm formation and 100 μg/mL for mature biofilm. Honokiol showed synergy effect with vancomycin and it significantly increased the sensitivity of mature biofilm to vancomycin. Polysaccharide intercellular adhesion formation and extracellular DNA release were effectively inhibited by honokiol. Extracellular DNA release decreased by 28.3% when honokiol at 1/8 MIC. After incubated with 1/2 MIC of honokiol for 16 h, the relative expression of icaA, cidA and agrA of MRSA41573 was reduced by 59.1%, 56% and 72.3%, respectively.
-   Honokiol can significantly inhibit biofilm formation of MRSA41573 and its mechanism is mainly the inhibited expression of icaA and cidA to influence the synthesis of polysaccharide intercellular adhesion and extracellular DNA. Moreover, it also affect biofilm formation by QS system.
Mesh:Anti-Bacterial Agents,Biofilms,Biphenyl Compounds,Drugs, Chinese Herbal,Humans,Lignans,Methicillin-Resistant Staphylococcus aureus,Microbial Sensitivity Tests,Staphylococcal Infections

  • anti biofilm
Pro-Apoptotic Activity of New Honokiol/Triphenylmethane Analogues in B-Cell Lymphoid Malignancies. [27483232]
Honokiol and triphenylmethanes are small molecules with anti-tumor properties. Recently, we synthesized new honokiol analogues (HAs) that possess common features of both groups. We assessed the anti-tumor effectiveness of HAs in B-cell leukemia/lymphoma cells, namely in chronic lymphocytic leukemia (CLL) cells ex vivo and in pre-B-cell acute lymphoblastic leukemia (Nalm-6), Burkitt lymphoma (BL; Raji), diffuse large B-cell lymphoma (DLBCL; Toledo) and multiple myeloma (MM; RPMI 8226) cell lines. Four of these compounds appeared to be significantly active against the majority of cells examined, with no significant impact on healthy lymphocytes. These active HAs induced caspase-dependent apoptosis, causing significant deregulation of several apoptosis-regulating proteins. Overall, these compounds downregulated Bcl-2 and XIAP and upregulated Bax, Bak and survivin proteins. In conclusion, some of the HAs are potent tumor-selective inducers of apoptosis in ex vivo CLL and in BL, DLBCL and MM cells in vitro. Further preclinical studies of these agents are recommended.
Mesh:Antineoplastic Agents,Apoptosis,Apoptosis Regulatory Proteins,Biphenyl Compounds,Cell Line, Tumor,Cell Proliferation,Cell Survival,Drug Screening Assays, Antitumor,Gene Expression Regulation, Neoplastic,Humans,Leukemia,Lignans,Lymphoma,Multiple Myeloma,Trityl Compounds
Keywords:ALL,BL,CLL,DLBCL,MM,honokiol analogues
  • anti lymph node cancer
c-Myc is a novel target of cell cycle arrest by honokiol in prostate cancer cells. [27341160]
Honokiol (HNK), a highly promising phytochemical derived from Magnolia officinalis plant, exhibits in vitro and in vivo anticancer activity against prostate cancer but the underlying mechanism is not fully clear. This study was undertaken to delineate the role of c-Myc in anticancer effects of HNK. Exposure of prostate cancer cells to plasma achievable doses of HNK resulted in a marked decrease in levels of total and/or phosphorylated c-Myc protein as well as its mRNA expression. We also observed suppression of c-Myc protein in PC-3 xenografts upon oral HNK administration. Stable overexpression of c-Myc in PC-3 and 22Rv1 cells conferred significant protection against HNK-mediated growth inhibition and G0-G1 phase cell cycle arrest. HNK treatment decreased expression of c-Myc downstream targets including Cyclin D1 and Enhancer of Zeste Homolog 2 (EZH2), and these effects were partially restored upon c-Myc overexpression. In addition, PC-3 and DU145 cells with stable knockdown of EZH2 were relatively more sensitive to growth inhibition by HNK compared with control cells. Finally, androgen receptor overexpression abrogated HNK-mediated downregulation of c-Myc and its targets particularly EZH2. The present study indicates that c-Myc, which is often overexpressed in early and late stages of human prostate cancer, is a novel target of prostate cancer growth inhibition by HNK.
Mesh:Biphenyl Compounds,Cell Cycle Checkpoints,Cell Line, Tumor,Cell Nucleus,Cell Proliferation,Down-Regulation,Gene Expression Regulation, Neoplastic,Humans,Lignans,Male,Phosphorylation,Prostatic Neoplasms,Proto-Oncogene Proteins c-myc,RNA, Messenger,Receptors, Androgen
Keywords:EZH2,androgen receptor,c-Myc,chemoprevention,honokiol,prostate cancer
  • anti prostrate cancer

Honokiol targets mitochondria to halt cancer progression and metastasis. [27276215] Cancer continues to be the leading cause of death worldwide. Plants have a long history of use in the treatment of cancer. Honokiol (HNK) is an important bioactive compound found in the bark of Magnolia tree, and has been shown to inhibit cancer growth and metastasis in many cell types in vitro and in animal models. Resistance to chemotherapy and radiotherapy is the major obstacle for cure of cancer. Combination of HNK with many traditional chemotherapeutic drugs as well as radiation sensitizes cancer cells to apoptotic death, suggesting that HNK not only directly inhibits primary cancers and metastasis, but also has potential to overcome drug resistance. Ultimately, this may mean that HNK could be combined with traditional chemotherapies administered at lower doses to significantly reduce toxicity, meanwhile enhance efficacy. As a natural compound, HNK is composed of polyphenols and has been described in many studies targeting multiple key cell signaling molecules. Mitochondria are the main hub for cellular energy production and play an important role in cell survival, and are the key target identified for HNK to mediate cancer cell death, survival, and metastasis. In this review, we have summarized different aspects of HNK's anti-cancer effects from recent accumulated literature, as well as the underlying molecular mechanisms. This review is primarily focused on the effects of HNK on epidermal growth factor receptor (EGFR) and signal transduction and activator of transcription 3 (STAT3) signaling, as well as the broader regulation of mitochondrial function and cancer cell metabolism. Mesh:Animals,Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Cell Line, Tumor,Disease Models, Animal,Humans,Lignans,Magnolia,Mitochondria,Neoplasms,Plant Extracts,Polyphenols,Receptor, Epidermal Growth Factor Keywords:Cancer Metastasis,Cancer Progression,Honokiol,Mitochondria,cancer cell metabolism
  • anti cancer

Novel histone deacetylase inhibitors derived from Magnolia officinalis significantly enhance TRAIL-induced apoptosis in non-small cell lung cancer. [27268146]
Histone modifications play critical roles in the progression of non-small cell lung cancer (NSCLC), which accounts for almost 85% of all diagnosed lung cancers. Magnolol and polyphenol mixture (PM) derived from Magnolia officinalis exhibited remarkable antitumor activities in lung cancer. However, the epigenetic effects and molecular mechanisms of magnolol and PM in NSCLC have yet to be reported. In this study, the epigenetic effects of magnolol and PM in NSCLC were examined in vitro and in vivo. Results revealed that magnolol and PM significantly suppressed the expression levels and function of class I histone deacetylases (HDACs). In A549 and H1299 cells, magnolol and PM remarkably induced cell apoptosis by arresting the cell cycle in the G0/G1 phase while simultaneously activating various pro-apoptotic signals, including TRAIL-R2 (DR5), Bax, caspase 3, cleaved caspase 3, and cleaved PARP. However, these apoptosis-promoting effects could be attenuated by TSA, which is a specific class I HDACs inhibitor. ChIP assays also demonstrated that magnolol and PM significantly enriched the histone acetyl mark (H3K27ac) in the promoter region of DR5. In A549 xenograft model, magnolol and PM notably reduced tumor growth by 44.40% and 35.40%, respectively. Therefore, magnolol and PM, as potential inhibitors of class I HDACs, induced tumor cell apoptosis and suppressed tumor growth partially by epigenetically activating DR5, which is a key protein in death receptor signaling pathway.
Mesh:A549 Cells,Acetylation,Animals,Antineoplastic Agents, Phytogenic,Antineoplastic Combined Chemotherapy Protocols,Apoptosis,Apoptosis Regulatory Proteins,Biphenyl Compounds,Carcinoma, Non-Small-Cell Lung,Cell Cycle Checkpoints,Cell Proliferation,Dose-Response Relationship, Drug,Epigenesis, Genetic,Female,Histone Deacetylase 1,Histone Deacetylase Inhibitors,Histones,Humans,Lignans,Lung Neoplasms,Magnolia,Mice, Inbred BALB C,Mice, Nude,Phytotherapy,Plant Extracts,Plants, Medicinal,Polyphenols,Promoter Regions, Genetic,Receptors, TNF-Related Apoptosis-Inducing Ligand,Signal Transduction,TNF-Related Apoptosis-Inducing Ligand,Time Factors,Tumor Burden,Xenograft Model Antitumor Assays
Keywords:Histone deacetylase,Honokiol (PubChem CID: 72303),Magnolol,Magnolol (PubChem CID: 72300),Non-small cell lung cancer,Obovatol (PubChem CID: 100771),Polyphenol mixture,TRAIL
– anti lung cancer

Honokiol suppresses TNF-α-induced neutrophil adhesion on cerebral endothelial cells by disrupting polyubiquitination and degradation of IκBα. [27212040]
Adhesion molecules expressed on cerebral endothelial cells (ECs) mediate leukocyte recruitment and play a significant role in cerebral inflammation. Increased levels of adhesion molecules on the EC surface induce leukocyte infiltration into inflammatory areas and are thus hallmarkers of inflammation. Honokiol, isolated from the Chinese medicinal herb Magnolia officinalis, has various pharmacological activities, including anti-inflammatory effects, yet the nature of honokiol targeting molecules remains to be revealed. Here, we investigated the inhibitory effect of honokiol on neutrophil adhesion and vascular cell adhesion molecule-1 (VCAM-1) expression, which underlie its molecular target, and mechanisms for inactivating nuclear factor κ enhancer binding protein (NF-κB) in mouse cerebral ECs. Honokiol inhibited tumour necrosis factor-α (TNF-α)-induced neutrophil adhesion and VCAM-1 gene expression in cerebral ECs. The inflammatory transcription factor NF-κB was downregulated by honokiol. Honokiol significantly blocked TNF-α-induced NF-κB p65 nuclear translocation and degradation of the proteasome-dependent inhibitor of NF-κB α (IκBα). From docking model prediction, honokiol directly targeted the ubiquitin-ubiquitin interface of Lys48-linked polychains. Moreover, honokiol prevented the TNF-α-induced Lys48-linked polyubiquitination, including IκBα-polyubiquitin interaction. Honokiol has protective anti-inflammatory effects on TNF-α-induced neutrophil adhesion and VCAM-1 gene expression in cerebral ECs, at least in part by directly inhibiting ubiquitination-mediated IκBα degradation and then preventing NF-κB nuclear translocation.
Mesh:Animals,Biphenyl Compounds,Brain,Cell Adhesion,Cells, Cultured,Endothelial Cells,Gene Expression Regulation,Humans,Lignans,Mice,NF-KappaB Inhibitor alpha,Neutrophils,Proteolysis,Tumor Necrosis Factor-alpha,Ubiquitination,Vascular Cell Adhesion Molecule-1

Honokiol inhibits sphere formation and xenograft growth of oral cancer side population cells accompanied with JAK/STAT signaling pathway suppression and apoptosis induction. [27012679]
Eliminating cancer stem cells (CSCs) has been suggested for prevention of tumor recurrence and metastasis. Honokiol, an active compound of Magnolia officinalis, had been proposed to be a potential candidate drug for cancer treatment. We explored its effects on the elimination of oral CSCs both in vitro and in vivo.
-   By using the Hoechst side population (SP) technique, CSCs-like SP cells were isolated from human oral squamous cell carcinoma (OSCC) cell lines, SAS and OECM-1. Effects of honokiol on the apoptosis and signaling pathways of SP-derived spheres were examined by Annexin V/Propidium iodide staining and Western blotting, respectively. The in vivo effectiveness was examined by xenograft mouse model and immunohistochemical tissue staining.
-   The SP cells possessed higher stemness marker expression (ABCG2, Ep-CAM, Oct-4 and Nestin), clonogenicity, sphere formation capacity as well as tumorigenicity when compared to the parental cells. Treatment of these SP-derived spheres with honokiol resulted in apoptosis induction via Bax/Bcl-2 and caspase-3-dependent pathway. This apoptosis induction was associated with marked suppression of JAK2/STAT3, Akt and Erk signaling pathways in honokiol-treated SAS spheres. Consistent with its effect on JAK2/STAT3 suppression, honokiol also markedly inhibited IL-6-mediated migration of SAS cells. Accordingly, honokiol dose-dependently inhibited the growth of SAS SP xenograft and markedly reduced the immunohistochemical staining of PCNA and endothelial marker CD31 in the xenograft tumor.
-   Honokiol suppressed the sphere formation and xenograft growth of oral CSC-like cells in association with apoptosis induction and inhibition of survival/proliferation signaling pathways as well as angiogenesis. These results suggest its potential as an integrative medicine for combating oral cancer through targeting on CSCs.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Cell Proliferation,Gene Expression Regulation, Neoplastic,Humans,Janus Kinases,Lignans,Mice,Mouth Neoplasms,Neoplasm Proteins,Neoplastic Stem Cells,STAT Transcription Factors,Side-Population Cells,Xenograft Model Antitumor Assays
Keywords:Cancer stem-like side population,Honokiol,JAK2/STAT3 pathway,Oral cancer

  • anti oral cancer
mTOR signaling pathway is inhibited downstream of the cyclophilin D-mediated mitochondrial permeability transition in honokiol-triggered regulated necrosis. [26936128]
Honokiol (HNK) is a pharmacologically active small molecule that is isolated from the traditional Chinese medicinal herb, houpu. It may induce diversified types of regulated cell death, which are dependent on different cell types and varying concentrations of therapeutic agent. We previously reported that HNK triggers a cyclophilin D (CypD)-mediated regulated necrosis in various cell lines at certain concentrations (two‑fold higher than its half maximal inhibitory concentration). Subsequent study revealed that HNK induced cell death transition from early apoptosis to regulated necrosis in parallel with the increase of HNK dose. In the current study, a lower concentration of HNK (30 µg/ml) than previously reported also induced simplex CypD‑mediated mitochondrial permeability transition (MPT)‑associated regulated necrosis in the HEK‑293 human embryonic kidney cell line. HNK, at concentration of 30 µg/ml, induced necrotic cell death in HEK‑293 cells, which was demonstrated by positive staining for propidium iodide. No DNA ladder patterns or apoptotic bodies were detected in cells that underwent this type of necrotic cell death. Caspase‑8 and ‑3 were not activated during the process of HNK‑induced necrosis. In addition, pan‑caspase inhibitor, z‑VAD‑fmk and receptor‑interacting protein 1 inhibitor, necrostatin‑1 did not inhibit HNK‑induced necrosis. However, CypD inhibitor, cyclosporin A (CsA), blocked HNK‑induced necrosis. These findings indicate that 30 µg/ml HNK induced simplex CypD-mediated MPT‑associated regulated necrosis in HEK‑293 cells. Furthermore, the findings demonstrated that during HNK-triggered regulated necrosis the mammalian target of rapamycin (mTOR) signaling pathway is also inhibited. Pretreatment with CsA, therefore, inhibits HNK‑triggered regulated necrosis and reverses dephosphorylation of Akt, eIF4E‑binding protein 1 and S6 kinase. This indicated that the mTOR signaling pathway is effective downstream of the CypD‑mediated MPT and before the onset of plasma membrane breakdown during the regulated necrosis process. Therefore, it has been demonstrated for the first time, to the best of our knowledge, that the mTOR signaling pathway was inhibited downstream of the CypD-mediated MPT in the process of HNK-induced regulated necrosis.
Mesh:Amino Acid Chloromethyl Ketones,Apoptosis,Biphenyl Compounds,Blotting, Western,Caspase 3,Caspase 8,Cyclophilins,Cyclosporine,HEK293 Cells,Humans,Imidazoles,Indoles,Lignans,Mitochondria,Nuclear Pore Complex Proteins,Permeability,RNA-Binding Proteins,Signal Transduction,TOR Serine-Threonine Kinases

  • mTOR inhibited

Honokiol protects against renal ischemia/reperfusion injury via the suppression of oxidative stress, iNOS, inflammation and STAT3 in rats. [26647858]
Honokiol is the predominant active ingredient in the commonly used traditional Chinese medicine, Magnolia, which has been confirmed in previous studies to exhibit anti-oxidation, antimicrobial, antitumor and other pharmacological effects. However, its effects on renal ischemia/reperfusion injury (IRI) remain to be elucidated. The present study aimed to examine the effects of honokiol on renal IRI, and to investigate its potential protective mechanisms in the heart. Male adult Wistar albino rats were induced into a renal IRI model. Subsequently, the levels of serum creatinine, blood urea nitrogen (BUN), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP), and the levels of serum nitrite and the kidney nitrite were examined in the IRI group. The levels of oxidative stress, inducible nitric oxide synthase (iNOS), inflammatory factors and caspase-3 were evaluated using a series of commercially available kits. The levels of phosphorylated signal transducer and activator of transcription 3 (p-STAT3) and the protein expression levels of STAT3 were determined using western blotting. Pretreatment with honokiol significantly reduced the levels of serum creatinine, BUN, ALT, AST and ALP, and the level of nitrite in the kidney of the IRI group, compared with the control group. The levels of malondialdehyde, the activity of myeloperoxidase, and the gene expression and activity of iNOS were reduced in the IRI rats, compared with the sham-operated rats, whereas the levels of superoxide dismutase and catalase were increased following treatment with honokiol in the IRI rats. In addition, the expression levels of tumor necrosis factor-α and interleukin-6 in the IRI rats were increased by honokiol. Treatment with honokiol suppressed the protein expression levels of p-STAT3 and caspase-3 in the IRI rats. These findings indicated that honokiol protects against renal IRI via the suppression of oxidative stress, iNOS, inflammation and STAT3 in the rat.
Mesh:Animals,Biphenyl Compounds,Gene Expression Regulation,Humans,Inflammation,Kidney,Lignans,Nitric Oxide Synthase Type II,Oxidative Stress,Rats,Reperfusion Injury,STAT3 Transcription Factor
Honokiol protects against renal ischemia/reperfusion injury via the suppression of oxidative stress, iNOS, inflammation and STAT3 in rats. [26647858]

Honokiol inhibits bladder tumor growth by suppressing EZH2/miR-143 axis. [26484567]
The oncoprotein EZH2, as a histone H3K27 methyltransferase, is frequently overexpressed in various cancer types. However, the mechanisms underlying its role in urinary bladder cancer (UBC) cells have not yet fully understood. Herein, we reported that honokiol, a biologically active biphenolic compound isolated from the Magnolia officinalis inhibited human UBC cell proliferation, survival, cancer stemness, migration, and invasion, through downregulation of EZH2 expression level, along with the reductions of MMP9, CD44, Sox2 and the induction of tumor suppressor miR-143. Either EZH2 overexpression or miR-143 inhibition could partially reverse honokiol-induced cell growth arrest and impaired clonogenicity. Importantly, it was first revealed that EZH2 could directly bind to the transcriptional regulatory region of miR-143 and repress its expression. Furthermore, honokiol treatment on T24 tumor xenografts confirmed its anticancer effects in vivo, including suppression tumor growth and tumor stemness, accompanied by the dysregulation of EZH2 and miR-143 expressions. Our data suggest a promising therapeutic option to develop drugs targeting EZH2/miR-143 axis, such as honokiol, for bladder cancer treatment.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Binding Sites,Biphenyl Compounds,Cell Line, Tumor,Cell Movement,Cell Proliferation,Dose-Response Relationship, Drug,Down-Regulation,Enhancer of Zeste Homolog 2 Protein,Gene Expression Regulation, Neoplastic,Humans,Hyaluronan Receptors,Lignans,Male,Matrix Metalloproteinase 9,Mice, Nude,MicroRNAs,Neoplasm Invasiveness,Neoplastic Stem Cells,Polycomb Repressive Complex 2,Promoter Regions, Genetic,SOXB1 Transcription Factors,Signal Transduction,Time Factors,Transcription, Genetic,Tumor Burden,Urinary Bladder Neoplasms,Xenograft Model Antitumor Assays
Keywords:EZH2,bladder cancer,honokiol,microRNA
– anti bladder cancer

Honokiol, a Lignan Biphenol Derived from the Magnolia Tree, Inhibits Dengue Virus Type 2 Infection. [26378567]
Dengue is the most widespread arbovirus infection and poses a serious health and economic issue in tropical and subtropical countries. Currently no licensed vaccine or compounds can be used to prevent or manage the severity of dengue virus (DENV) infection. Honokiol, a lignan biphenol derived from the Magnolia tree, is commonly used in Eastern medicine. Here we report that honokiol has profound antiviral activity against serotype 2 DENV (DENV-2). In addition to inhibiting the intracellular DENV-2 replicon, honokiol was shown to suppress the replication of DENV-2 in baby hamster kidney (BHK) and human hepatocarcinoma Huh7 cells. At the maximum non-toxic dose of honokiol treatment, the production of infectious DENV particles was reduced >90% in BHK and Huh7 cells. The underlying mechanisms revealed that the expression of DENV-2 nonstructural protein NS1/NS3 and its replicating intermediate, double-strand RNA, was dramatically reduced by honokiol treatment. Honokiol has no effect on the expression of DENV putative receptors, but may interfere with the endocytosis of DENV-2 by abrogating the co-localization of DENV envelope glycoprotein and the early endosomes. These results indicate that honokiol inhibits the replication, viral gene expression, and endocytotic process of DENV-2, making it a promising agent for chemotherapy of DENV infection.
Mesh:Animals,Antiviral Agents,Biphenyl Compounds,Cells, Cultured,Cricetinae,Dengue Virus,Gene Expression Regulation, Viral,Humans,Lignans,Magnolia,Virus Internalization,Virus Replication
Keywords:Magnolia,antiviral,dengue virus,honokiol
– anti Dengue Virus Type 2 Infection

Honokiol possesses potential anti-inflammatory effects on rheumatoid arthritis and GM-CSF can be a target for its treatment. [26339358]
To observe the anti-inflammatory effects of honokiol in primary cultures of peripheral blood mononuclear cells of rheumatoid arthritis patients, the pro-inflammatory cytokines and potential targets were investigated.
-   The levels of GM-CSF, IL-1β, TNF-α and IL-8 were determined by ELISA assay. The genes and proteins expression were analyzed by real-time PCR and Western blotting respectively.
-   The serum IL-1β, TNF-α and GM-CSF levels were 1.76-, 2.16- and 3.57-fold increased in patients with RA as compared to those of control group. Honokiol inhibited the expression levels of IL-1β, TNF-α, GM-CSF and IL-8 in PBMCs with a dose-dependent manner. Measurements obtained from supernatants were positively correlated between TNF-α and IL-1β, moreover, similar results found TNF-α levels positively correlated with GM-CSF and IL-8 activity in the supernatants of PBMCs isolated from RA patients. Furthermore, the mRNA and protein expression of IL-1β, GM-CSF and IL-8 were up-regulated when the PBMCs exposure to TNF-α, however, honokiol treatment significantly reversed the expression of IL-1β, TNF-α and GM-CSF in response to TNF-α with a dose-dependent manner.
-   This study demonstrates that honokiol could possess potential anti-inflammatory effects and inhibits TNF-α-induced IL-1β, GM-CSF and IL-8 production in PBMCs from rheumatoid arthritis patients.
Mesh:Adult,Aged,Anti-Inflammatory Agents,Antirheumatic Agents,Arthritis, Rheumatoid,Biphenyl Compounds,Case-Control Studies,Cells, Cultured,Dose-Response Relationship, Drug,Female,Granulocyte-Macrophage Colony-Stimulating Factor,Humans,Inflammation Mediators,Interleukin-1beta,Interleukin-8,Leukocytes, Mononuclear,Lignans,Male,Middle Aged,Primary Cell Culture,Signal Transduction,Tumor Necrosis Factor-alpha
Keywords:GM-CSF,IL-1β,IL-8,Rheumatoid arthritis,TNF-α
  • anti-inflammatory effects on rheumatoid arthritis
Inhibitory effects of magnolol and honokiol on human calcitonin aggregation. [26324190]
Amyloid formation is associated with multiple amyloidosis diseases. Human calcitonin (hCT) is a typical amyloidogenic peptide, its aggregation is associated with medullary carcinoma of the thyroid (MTC), and also limits its clinical application. Magnolia officinalis is a traditional Chinese herbal medicine; its two major polyphenol components, magnolol (Mag) and honokiol (Hon), have displayed multiple functions. Polyphenols like flavonoids and their derivatives have been extensively studied as amyloid inhibitors. However, the anti-amyloidogenic property of a biphenyl backbone containing polyphenols such as Mag and Hon has not been reported. In this study, these two compounds were tested for their effects on hCT aggregation. We found that Mag and Hon both inhibited the amyloid formation of hCT, whereas Mag showed a stronger inhibitory effect; moreover, they both dose-dependently disassembled preformed hCT aggregates. Further immuno-dot blot and dynamic light scattering studies suggested Mag and Hon suppressed the aggregation of hCT both at the oligomerization and the fibrillation stages, while MTT-based and dye-leakage assays demonstrated that Mag and Hon effectively reduced cytotoxicity caused by hCT aggregates. Furthermore, isothermal titration calorimetry indicated Mag and Hon both interact with hCT. Together, our study suggested a potential anti-amyloidogenic property of these two compounds and their structure related derivatives.
Mesh:Biphenyl Compounds,Calcitonin,Calorimetry,Cell Line, Tumor,Dynamic Light Scattering,Humans,Lignans,Magnolia,Medicine, Chinese Traditional,Microscopy, Electron, Transmission,Polyphenols,Protein Binding
  • anti-amyloidogenic
Anti-psoriatic effects of Honokiol through the inhibition of NF-κB and VEGFR-2 in animal model of K14-VEGF transgenic mouse. [26220468]
Honokiol (HK), a biphenolic neolignan isolated from Magnolia officinalis, has been reported to possess anti-inflammatory and anti-angiogenic activaties. In this study, our aim was to investigate anti-psoriatic activities of HK and the involved mechanisms. In vitro, the effects of HK on the regulation of Th1/Th2 and TNF-α-induced NF-κB (p65) activation were analyzed by respective FCS and immunofluorescence. Additionally, the K14-VEGF transgenic model was used for the in vivo study. ELISA and Q-PCR were performed to evaluate serum levels of Th1/Th2 cytokines and their corresponding mRNA expressions. Effects on VEGFR-2 and p65 activation, as well as other angiogenic and inflammatory parameters were studied by immunostainings. Importantly, we found that HK significantly decreased the ratio of Th1/Th2-expression CD4(+) T cells and inhibited TNF-α-induced activation of NF-κB. The morphology and histological features of psoriasis were effectively improved by HK treatment. The expression of TNF-α and IFN-γ, and their corresponding mRNA levels were down-regulated and the expression of nuclear p65, VEGFR-2, as well as related phosphorylated proteins (p-VEGFR-2, p-ERK1/2, p-AKT and p-p38) were also suppressed. Overall, these results in our study suggested that HK exhibits anti-psoriatic effects through the inhibition of NF-κB and VEGFR-2.
Mesh:Angiogenesis Inhibitors,Animals,Anti-Inflammatory Agents,Biphenyl Compounds,CD4-Positive T-Lymphocytes,Cells, Cultured,Disease Models, Animal,Down-Regulation,Gene Expression,Human Umbilical Vein Endothelial Cells,Humans,Lignans,Magnolia,Mice, Transgenic,Molecular Targeted Therapy,NF-kappa B,Phosphorylation,Phytotherapy,Psoriasis,Th1-Th2 Balance,Tumor Necrosis Factor-alpha,Vascular Endothelial Growth Factor A,Vascular Endothelial Growth Factor Receptor-2
  • Anti-psoriatic
Honokiol ameliorates endothelial dysfunction through suppression of PTX3 expression, a key mediator of IKK/IκB/NF-κB, in atherosclerotic cell model. [26138903]
Pentraxin 3 (PTX3) was identified as a marker of the inflammatory response and overexpressed in various tissues and cells related to cardiovascular disease. Honokiol, an active component isolated from the Chinese medicinal herb Magnolia officinalis, was shown to have a variety of pharmacological activities. In the present study, we aimed to investigate the effects of honokiol on palmitic acid (PA)-induced dysfunction of human umbilical vein endothelial cells (HUVECs) and to elucidate potential regulatory mechanisms in this atherosclerotic cell model. Our results showed that PA significantly accelerated the expression of PTX3 in HUVECs through the IκB kinase (IKK)/IκB/nuclear factor-κB (NF-κB) pathway, reduced cell viability, induced cell apoptosis and triggered the inflammatory response. Knockdown of PTX3 supported cell growth and prevented apoptosis by blocking PA-inducted nitric oxide (NO) overproduction. Honokiol significantly suppressed the overexpression of PTX3 in PA-inducted HUVECs by inhibiting IκB phosphorylation and the expression of two NF-κB subunits (p50 and p65) in the IKK/IκB/NF-κB signaling pathway. Furthermore, honokiol reduced endothelial cell injury and apoptosis by regulating the expression of inducible NO synthase and endothelial NO synthase, as well as the generation of NO. Honokiol showed an anti-inflammatory effect in PA-inducted HUVECs by significantly inhibiting the generation of interleukin-6 (IL-6), IL-8 and monocyte chemoattractant protein-1. In summary, honokiol repaired endothelial dysfunction by suppressing PTX3 overexpression in an atherosclerotic cell model. PTX3 may be a potential therapeutic target for atherosclerosis.
Mesh:Apoptosis,Atherosclerosis,Biphenyl Compounds,C-Reactive Protein,Down-Regulation,Drugs, Chinese Herbal,Human Umbilical Vein Endothelial Cells,Humans,I-kappa B Kinase,Lignans,Magnolia,Palmitic Acid,Protein-Serine-Threonine Kinases,Serum Amyloid P-Component,Signal Transduction
  • Honokiol ameliorates endothelial

Honokiol abrogates leptin-induced tumor progression by inhibiting Wnt1-MTA1-β-catenin signaling axis in a microRNA-34a dependent manner. [26036628]
Obesity greatly influences risk, progression and prognosis of breast cancer. As molecular effects of obesity are largely mediated by adipocytokine leptin, finding effective novel strategies to antagonize neoplastic effects of leptin is desirable to disrupt obesity-cancer axis. Present study is designed to test the efficacy of honokiol (HNK), a bioactive polyphenol from Magnolia grandiflora, against oncogenic actions of leptin and systematically elucidate the underlying mechanisms. Our results show that HNK significantly inhibits leptin-induced breast-cancer cell-growth, invasion, migration and leptin-induced breast-tumor-xenograft growth. Using a phospho-kinase screening array, we discover that HNK inhibits phosphorylation and activation of key molecules of leptin-signaling-network. Specifically, HNK inhibits leptin-induced Wnt1-MTA1-β-catenin signaling in vitro and in vivo. Finally, an integral role of miR-34a in HNK-mediated inhibition of Wnt1-MTA1-β-catenin axis was discovered. HNK inhibits Stat3 phosphorylation, abrogates its recruitment to miR-34a promoter and this release of repressor-Stat3 results in miR-34a activation leading to Wnt1-MTA1-β-catenin inhibition. Accordingly, HNK treatment inhibited breast tumor growth in diet-induced-obese mouse model (exhibiting high leptin levels) in a manner associated with activation of miR-34a and inhibition of MTA1-β-catenin. These data provide first in vitro and in vivo evidence for the leptin-antagonist potential of HNK revealing a crosstalk between HNK and miR34a and Wnt1-MTA1-β-catenin axis.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Breast Neoplasms,Cell Movement,Cell Proliferation,Cell Transformation, Neoplastic,Cyclin D1,Drugs, Chinese Herbal,Female,Histone Deacetylases,Humans,Leptin,Lignans,MCF-7 Cells,Magnolia,Mice,Mice, Nude,Mice, Obese,MicroRNAs,Neoplasm Invasiveness,Obesity,Phosphorylation,Plant Extracts,Promoter Regions, Genetic,RNA Interference,RNA, Small Interfering,Repressor Proteins,STAT3 Transcription Factor,Signal Transduction,Spheroids, Cellular,Tumor Cells, Cultured,Wnt1 Protein,Xenograft Model Antitumor Assays,beta Catenin
Keywords:breast cancer,honokiol,leptin,miR-34a
– anti tuomor

Honokiol inhibits the growth of head and neck squamous cell carcinoma by targeting epidermal growth factor receptor. [26020804]
Here, we report the chemotherapeutic effect of honokiol, a phytochemical from Magnolia plant, on human head and neck squamous cell carcinoma (HNSCC). Treatment of HNSCC cell lines from different sub-sites, SCC-1 (oral cavity), SCC-5 (larynx), OSC-19 (tongue) and FaDu (pharynx) with honokiol inhibited their cell viability, which was associated with the: (i) induction of apoptosis, (ii) correction of dysregulatory cell cycle proteins of G0/G1 phase. Honokiol decreased the expression levels of epidermal growth factor receptor (EGFR), mTOR and their downstream signaling molecules. Treatment of FaDu and SCC-1 cell lines with rapamycin, an inhibitor of mTOR pathway, also reduced cell viability of HNSCC cells. Administration of honokiol by oral gavage (100 mg/kg body weight) significantly (P < 0.01-0.001) inhibited the growth of SCC-1 and FaDu xenografts in athymic nude mice, which was associated with: (i) inhibition of tumor cell proliferation, (ii) induction of apoptosis, (iii) reduced expressions of cyclins and Cdks, and (iv) inhibition of EGFR signaling pathway. Molecular docking analysis of honokiol in EGFR binding site indicated that the chemotherapeutic effect of honokiol against HNSCC is mediated through its firm binding with EGFR, which is better than that of gefitinib, a commonly used drug for HNSCC treatment.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Apoptosis,Binding Sites,Biphenyl Compounds,Carcinoma, Squamous Cell,Cell Cycle,Cell Line, Tumor,Cell Proliferation,Cell Separation,Cell Survival,Dose-Response Relationship, Drug,Female,Flow Cytometry,Head and Neck Neoplasms,Humans,Lignans,Magnolia,Mice,Mice, Nude,Molecular Docking Simulation,Phytotherapy,Plant Extracts,Receptor, Epidermal Growth Factor,Signal Transduction,Sirolimus
Keywords:animal model,carcinogenesis,chemotherapy,oncology,prevention,signal transduction,targeted therapy
– anti squamous cell carcinoma

The anti-inflammatory effect of 2-(4-hydroxy-3-prop-2-enyl-phenyl)-4-prop-2-enyl-phenol by targeting Lyn kinase in human neutrophils. [25980585]
The undesirable respiratory burst in neutrophils can lead to inflammation and tissue damage. This study investigates the effect and the underlying mechanism of 2-(4-hydroxy-3-prop-2-enyl-phenyl)-4-prop-2-enyl-phenol (honokiol), a lignan extracted from the stem bark of Magnolia officinalis Rehd. et Wils (Magnoliaceae), on N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP)-induced respiratory burst in human neutrophils. Signaling pathways regulated by honokiol which modulate fMLP-induced respiratory burst and cathepsin G release were evaluated by phosphorylation of Src family kinase induced by fMLP, Src family kinases activities and by immunoblotting analysis of the downstream targets of Src kinase. Briefly, honokiol inhibited fMLP-induced superoxide anion production (IC50 = 9.80 ± 0.21 μM, n = 4), cathepsin G release (IC50 = 14.23 ± 1.43 μM, n = 4) and migration (IC50 = 5.69 ± 1.51 μM, n = 4) in a concentration dependent manner. Further, honokiol specifically suppresses fMLP-induced Lyn (a member of the Src kinase family) phosphorylation, by inhibiting Lyn kinase activity. Consequently, honokiol attenuated the downstream targets of Lyn kinase, such as Tec translocation from the cytosol to the inner leaflet of the plasma membrane, phosphorylation of AKT, P38, PLCγ2, protein kinase C and membrane localization of p47(phox). On the other hand, fMLP-induced phosphorylation of Hck, Fgr kinase activity (other members of Src kinase), downstream phosphorylation of Vav1 and extracellular signal-regulated kinase remained unaffected. In addition, honokiol neither inhibited NADPH oxidase activity nor increased cyclic AMP levels. Honokiol is not a competitive or allosteric antagonist of fMLP. In conclusion, honokiol specifically modulates fMLP-mediated neutrophil activation by inhibiting Lyn activation which subsequently interferes with the activation of PLCγ2, AKT, p38, protein kinase C, and p47(phox).
Mesh:Adult,Anti-Inflammatory Agents, Non-Steroidal,Biphenyl Compounds,Calcium,Cathepsin G,Cell Movement,Cyclic AMP,Humans,Lignans,N-Formylmethionine Leucyl-Phenylalanine,NADPH Oxidases,Neutrophils,Phospholipase C gamma,Phosphorylation,Proto-Oncogene Proteins c-akt,Receptors, Formyl Peptide,Respiratory Burst,Superoxides,Young Adult,src-Family Kinases
– anti-inflammatory

New mechanism of magnolol and honokiol from Magnolia officinalis against Staphylococcus aureus. [25918799]
Cell division protein, FtsZ, has been identified as a new potential antimicrobial target against multidrug-resistant (MDR) and methicillin-resistant Staphylococcus aureus (MRSA). By using computer-aided simulation, the phenolic compounds magnolol and honokiol from Magnolia officinalis were shown to have high anchor energies to FtsZ of S. aureus. The calculated binding energies of magnolol and honokiol for this FtsZ (PDB Code: 4DXD) were established to be -7.6 kcal/mol and -8.2 kcal/mol, respectively. Both of them showed polymerization inhibition efficacy for this FtsZ at 100 ppm, which confirmed the simulation results. Their antibacterial activity against S. aureus including multidrug-resistant (MDR) and methicillin-resistant S. aureus (MRSA) with minimum inhibitory concentration (MIC) values in the range of 8-16 ppm. These findings support the use of computer-aided simulation to screen natural compounds for this cell division protein, FtsZ, and this method can be a quick and promising approach for the development of antimicrobial agents against multi-drug resistant S. aureus.
Mesh:Anti-Bacterial Agents,Biphenyl Compounds,Humans,Lignans,Magnolia,Methicillin-Resistant Staphylococcus aureus,Microbial Sensitivity Tests,Plant Exudates,Staphylococcal Infections,Staphylococcus aureus
– anti Staphylococcus aureus

Multifunctional effects of honokiol as an anti-inflammatory and anti-cancer drug in human oral squamous cancer cells and xenograft. [25890726]
The aim of this study was to investigate anti-inflammatory and anti-cancer effects of honokiol (HK) in two oral squamous cancer cell carcinoma (OSCC) cell lines, HN22 and HSC4, through the regulation of inducible nitric oxide synthase (iNOS) and endoplasmic reticulum resident protein 44 (ERp44). Griess assay, zymography, and quantitative PCR were performed to study iNOS expression and subsequent nitric oxide (NO) production in OSCC cell lines. Liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomic analysis was used to elucidate the proteins associated with ER stress and cellular cytotoxic response induced by HK. Pull-down assay and molecular modeling were performed to better understand how HK interacts with ERp44. In vitro and in vivo experiments in which ERp44 expression was knocked down were performed to better understand the effects of ERp44 on a cellular level and anti-cancer effects of HK. Expression levels of iNOS and subsequent NO secretion were reduced in OSCC cell lines treated with HK. ERp44 was significantly decreased in OSCC cell lines by HK treatment. HK directly bound to ERp44, and ERp44 knock-down significantly inhibited oral cancer cell proliferation and colony formation. Moreover, HK treatment effectively inhibited tumor growth and ERp44 levels in BALB/c nude mice bearing HN22 cell xenografts. Our findings suggest that HK inhibited inflammation and induced apoptosis by suppressing both iNOS/NO and ERp44 expression in HN22 and HSC4 cells and xenograft tumors, and thus could be a potent anti-inflammatory and anti-cancer drug candidate for human oral cancer treatment.
Mesh:Animals,Anti-Inflammatory Agents,Antineoplastic Agents,Apoptosis,Biphenyl Compounds,Calcium,Carcinoma, Squamous Cell,Chromatography, Liquid,Humans,Lignans,Matrix Metalloproteinase 2,Matrix Metalloproteinase 9,Membrane Potential, Mitochondrial,Mice,Mice, Nude,Mouth Neoplasms,NF-kappa B,Nitric Oxide Synthase Type II,Oxidation-Reduction,Tandem Mass Spectrometry,Xenograft Model Antitumor Assays
Keywords:Apoptosis,Endoplasmic reticulum resident protein 44,Honokiol,Oral squamous cell carcinoma,Proteomics,Xenograft
– anti human oral squamous cancer

Honokiol suppresses metastasis of renal cell carcinoma by targeting KISS1/KISS1R signaling. [25846316]
Renal cell carcinoma (RCC) is a common urological cancer worldwide and is known to have a high risk of metastasis, which is considered responsible for more than 90% of cancer associated deaths. Honokiol is a small-molecule biphenol isolated from Magnolia spp. bark and has been shown to be a potential anticancer agent involved in multiple facets of signal transduction. In this study, we demonstrated that honokiol inhibited the invasion and colony formation of highly metastatic RCC cell line 786-0 in a dose-dependent manner. DNA-microarray data showed the significant upregulation of metastasis-suppressor gene KISS1 and its receptor, KISS1R. The upregulation was confirmed by qRT-PCR analysis. Overexpression of KISS1 and KISS1R was detected by western blotting at the translation level as well. Of note, the decreased invasive and colonized capacities were reversed by KISS1 knockdown. Taken together, the results first indicate that activation of KISS1/KISS1R signaling by honokiol suppresses multistep process of metastasis, including invasion and colony formation, in RCC cells 786-0. Honokiol may be considered as a natural agent against RCC metastasis.
Mesh:Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Carcinoma, Renal Cell,Cell Line, Tumor,Cell Movement,Dose-Response Relationship, Drug,Gene Expression Regulation, Neoplastic,Humans,Kidney Neoplasms,Kisspeptins,Lignans,Neoplasm Invasiveness,Receptors, G-Protein-Coupled,Receptors, Kisspeptin-1,Signal Transduction
– anti renal cancer

Elimination of cancer stem-like cells and potentiation of temozolomide sensitivity by Honokiol in glioblastoma multiforme cells. [25763821]
Glioblastoma multiforme (GBM) is the most common adult malignant glioma with poor prognosis due to the resistance to radiotherapy and chemotherapy, which might be critically involved in the repopulation of cancer stem cells (CSCs) after treatment. We had investigated the characteristics of cancer stem-like side population (SP) cells sorted from GBM cells, and studied the effect of Honokiol targeting on CSCs. GBM8401 SP cells possessed the stem cell markers, such as nestin, CD133 and Oct4, and the expressions of self-renewal related stemness genes, such as SMO, Notch3 and IHH (Indian Hedgehog). Honokiol inhibited the proliferation of both GBM8401 parental cells and SP cells in a dose-dependent manner, the IC50 were 5.3±0.72 and 11±1.1 μM, respectively. The proportions of SP in GBM8401 cells were diminished by Honokiol from 1.5±0.22% down to 0.3±0.02% and 0.2±0.01% at doses of 2.5 μM and 5 μM, respectively. The SP cells appeared to have higher expression of O6-methylguanine-DNA methyltransferase (MGMT) and be more resistant to Temozolomide (TMZ). The resistance to TMZ could be only slightly reversed by MGMT inhibitor O6-benzylguanine (O6-BG), but markedly further enhanced by Honokiol addition. Such significant enhancement was accompanied with the higher induction of apoptosis, greater down-regulation of Notch3 as well as its downstream Hes1 expressions in SP cells. Our data indicate that Honokiol might have clinical benefits for the GBM patients who are refractory to TMZ treatment.
Mesh:Antineoplastic Agents,Apoptosis,Basic Helix-Loop-Helix Transcription Factors,Biphenyl Compounds,Brain Neoplasms,Cell Proliferation,Dacarbazine,Dose-Response Relationship, Drug,Down-Regulation,Drug Synergism,Drug Therapy, Combination,Glioblastoma,Homeodomain Proteins,Humans,Lignans,Neoplastic Stem Cells,Receptor, Notch3,Receptors, Notch,Transcription Factor HES-1,Tumor Cells, Cultured
Elimination of cancer stem-like cells

Honokiol activates the LKB1-AMPK signaling pathway and attenuates the lipid accumulation in hepatocytes. [25737164]
Honokiol is a bioactive neolignan compound isolated from the species of Magnolia. This study was designed to elucidate the cellular mechanism by which honokiol alleviates the development of non-alcoholic steatosis. HepG2 cells were treated with honokiol for 1h, and then exposed to 1mM free fatty acid (FFA) for 24h to simulate non-alcoholic steatosis in vitro. C57BL/6 mice were fed with a high-fat diet for 28days, and honokiol (10mg/kg/day) was daily treated. Honokiol concentration-dependently attenuated intracellular fat overloading and triglyceride (TG) accumulation in FFA-exposed HepG2 cells. These effects were blocked by pretreatment with an AMP-activated protein kinase (AMPK) inhibitor. Honokiol significantly inhibited sterol regulatory element-binding protein-1c (SREBP-1c) maturation and the induction of lipogenic proteins, stearoyl-CoA desaturase-1 (SCD-1) and fatty acid synthase (FAS) in FFA-exposed HepG2 cells, but these effects were blocked by pretreatment of an AMPK inhibitor. Honokiol induced AMPK phosphorylation and subsequent acetyl-CoA carboxylase (ACC) phosphorylation, which were inhibited by genetic deletion of liver kinase B1 (LKB1). Honokiol stimulated LKB1 phosphorylation, and genetic deletion of LKB1 blocked the effect of honokiol on SREBP-1c maturation and the induction of SCD-1 and FAS proteins in FFA-exposed HepG2 cells. Honokiol attenuated the increases in hepatic TG and lipogenic protein levels and fat accumulation in the mice fed with high-fat diet, while significantly induced LKB1 and AMPK phosphorylation. Taken together, our findings suggest that honokiol has an anti-lipogenic effect in hepatocytes, and this effect may be mediated by the LKB1-AMPK signaling pathway, which induces ACC phosphorylation and inhibits SREBP-1c maturation in hepatocytes.
Mesh:AMP-Activated Protein Kinases,Acetyl-CoA Carboxylase,Animals,Biphenyl Compounds,Cell Line, Tumor,Diet, High-Fat,Fatty Acid Synthases,Fatty Acids, Nonesterified,Hep G2 Cells,Hepatocytes,Humans,Lignans,Lipid Metabolism,Lipogenesis,Liver,Male,Mice,Mice, Inbred C57BL,Phosphorylation,Protein-Serine-Threonine Kinases,Signal Transduction,Stearoyl-CoA Desaturase,Sterol Regulatory Element Binding Protein 1,Triglycerides
Keywords:Adenosine monophosphate-activated protein kinase,Hepatocytes,Honokiol,Lipogenesis,Liver kinase B1,Non-alcoholic steatosis
– attenuates the lipid accumulation in hepatocytes

Honokiol confers immunogenicity by dictating calreticulin exposure, activating ER stress and inhibiting epithelial-to-mesenchymal transition. [25619450]
Peritoneal dissemination is a major clinical obstacle in gastrointestinal cancer therapy, and it accounts for the majority of cancer-related mortality. Calreticulin (CRT) is over-expressed in gastric tumors and has been linked to poor prognosis. In this study, immunohistochemistry studies revealed that the up-regulation of CRT was associated with lymph node and distant metastasis in patients with gastric cancer specimens. CRT was significantly down-regulated in highly metastatic gastric cancer cell lines and metastatic animal by Honokiol-treated. Small RNA interference blocking CRT by siRNA-CRT was translocated to the cells in the early immunogenic response to Honokiol. Honokiol activated endoplasmic reticulum (ER) stress and down-regulated peroxisome proliferator-activated receptor-γ (PPARγ) activity resulting in PPARγ and CRT degradation through calpain-II activity, which could be reversed by siRNA-calpain-II. The Calpain-II/PPARγ/CRT axis and interaction evoked by Honokiol could be blocked by gene silencing or pharmacological agents. Both transforming growth factor (TGF)-β1 and N-methyl-N’-nitro-N-nitrosoguanidine (MNNG) induced cell migration, invasion and reciprocal down-regulation of epithelial marker E-cadherin, which could be abrogated by siRNA-CRT. Moreover, Honokiol significantly suppressed MNNG-induced gastrointestinal tumor growth and over-expression of CRT in mice. Knockdown CRT in gastric cancer cells was found to effectively reduce growth ability and metastasis in vivo. The present study provides insight into the specific biological behavior of CRT in epithelial-to-mesenchymal transition (EMT) and metastasis. Taken together, our results suggest that the therapeutic inhibition of CRT by Honokiol suppresses both gastric tumor growth and peritoneal dissemination by dictating early translocation of CRT in immunogenic cell death, activating ER stress, and blocking EMT.
Mesh:Adult,Animals,Biomarkers, Tumor,Biphenyl Compounds,Calpain,Calreticulin,Cell Death,Cell Line, Tumor,Down-Regulation,Endoplasmic Reticulum Stress,Epithelial-Mesenchymal Transition,Female,Gene Knockdown Techniques,Humans,Lignans,Macrophages,Male,Methylnitronitrosoguanidine,Mice, Inbred BALB C,Mice, Inbred C57BL,Middle Aged,Neoplasm Invasiveness,PPAR gamma,Phagocytosis,Promoter Regions, Genetic,Protein Binding,Stomach Neoplasms,Up-Regulation
Keywords:Calreticulin,Carcinogenesis,Endoplasmic reticulum stress,Epithelial-to-mesenchymal transition,Immunogenic cell death

The herbal-derived honokiol and magnolol enhances immune response to infection with methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA). [25586586]
The emergence of antibiotic resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA) reminds us an urgent need to develop a new immune-modulating agent for preventing S. aureus infection. In this study, we found that herbal medicines, honokiol and magnolol, caused a significant cellular immune modulatory effect during S. aureus infection. In mouse macrophages, these compounds drove upregulation of an antioxidant effect in response to S. aureus, resulting in a dampened total cellular reactive oxygen species (ROS) production and decreased production of inflammatory cytokines/chemokines, whereas honokiol induced increased types I and III interferon messenger RNA (mRNA) expression levels in response to MSSA infection. Moreover, the internalization of S. aureus by human alveolar epithelial cells was inhibited by these compounds. Furthermore, honokiol and magnolol treatment promoted a delay in killing during MSSA infection in Caenorhabditis elegans, suggesting antimicrobial function in vivo. In conclusion, honokiol and magnolol may be considered as attractive immune-modulating treatment for S. aureus infection.
Mesh:Animals,Anti-Bacterial Agents,Biphenyl Compounds,Caenorhabditis elegans,Cytokines,Humans,Lignans,Macrophages,Methicillin,Methicillin-Resistant Staphylococcus aureus,Mice,Plant Extracts,Plants, Medicinal,Staphylococcal Infections,Staphylococcus aureus
enhances immune response to infection

Evaluation of anti-HIF and anti-angiogenic properties of honokiol for the treatment of ocular neovascular diseases. [25422886]
Pathological activation of the hypoxia-inducible-factor (HIF) pathway leading to expression of pro-angiogenic genes, such as vascular endothelial growth factor (VEGF), is the fundamental cause of neovascularization in ocular ischemic diseases and cancers. We have shown that pure honokiol inhibits the HIF pathway and hypoxia-mediated expression of pro-angiogenic genes in a number of cancer and retinal pigment epithelial (RPE) cell lines. The crude extracts, containing honokiol, from Magnolia plants have been used for thousands of years in the traditional oriental medicine for a number of health benefits. We have recently demonstrated that daily intraperitoneal injection of honokiol starting at postnatal day (P) 12 in an oxygen induced retinopathy mouse model significantly reduced retinal neovascularization at P17. Here, we evaluate the mechanism of HIF inhibition by honokiol in RPE cells. Using chromatin immunoprecipitation experiments, we demonstrate that honokiol inhibits binding of HIF to hypoxia-response elements present on VEGF promoter. We further show using a number of in vitro angiogenesis assays that, in addition to anti-HIF effect, honokiol manifests potent anti-angiogenic effect on human retinal micro vascular endothelial cells. Our results suggest that honokiol possesses potent anti-HIF and anti-angiogenic properties. These properties of honokiol make it an ideal therapeutic agent for the treatment of ocular neovascular diseases and solid tumors.
Mesh:Angiogenesis Inhibitors,Biphenyl Compounds,Cell Line,Cell Movement,Cell Proliferation,Endothelium, Vascular,Eye Diseases,HeLa Cells,Humans,Hypoxia-Inducible Factor 1,Lignans,Luciferases,Neovascularization, Pathologic,Retinal Pigment Epithelium
– anti ocular neovascular diseases

Combination of honokiol and magnolol inhibits hepatic steatosis through AMPK-SREBP-1 c pathway. [25125496]
Honokiol and magnolol, as pharmacological biphenolic compounds of Magnolia officinalis, have been reported to have antioxidant and anti-inflammatory properties. Sterol regulatory element binding protein-1 c (SREBP-1 c) plays an important role in the development and processing of steatosis in the liver. In the present study, we investigated the effects of a combination of honokiol and magnolol on SREBP-1 c-dependent lipogenesis in hepatocytes as well as in mice with fatty liver due to consumption of high-fat diet (HFD). Liver X receptor α (LXRα) agonists induced activation of SREBP-1 c and expression of lipogenic genes, which were blocked by co-treatment of honokiol and magnolol (HM). Moreover, a combination of HM potently increased mRNA of fatty acid oxidation genes. HM induced AMP-activated protein kinase (AMPK), an inhibitory kinase of the LXRα-SREBP-1 c pathway. The role of AMPK activation induced by HM was confirmed using an inhibitor of AMPK, Compound C, which reversed the ability of HM to both inhibit SREBP-1 c induction as well as induce genes for fatty acid oxidation. In mice, HM administration for four weeks ameliorated HFD-induced hepatic steatosis and liver dysfunction, as indicated by plasma parameters and Oil Red O staining. Taken together, our results demonstrated that a combination of HM has beneficial effects on inhibition of fatty liver and SREBP-1 c-mediated hepatic lipogenesis, and these events may be mediated by AMPK activation.
Mesh:AMP-Activated Protein Kinases,Animals,Biphenyl Compounds,Cell Line,Diet, High-Fat,Disease Models, Animal,Drug Synergism,Drug Therapy, Combination,Enzyme Inhibitors,Fatty Liver,Hepatocytes,Humans,Lignans,Lipogenesis,Liver X Receptors,Male,Mice,Mice, Inbred C57BL,Orphan Nuclear Receptors,Signal Transduction,Sterol Regulatory Element Binding Protein 1
Keywords:AMP-activated protein kinase,Honokiol,hepatic steatosis,magnolol,sterol regulatory element binding protein-1 c
– inhibits hepatic steatosis

additional mostly the same

HIF inhibitors for ischemic retinopathies and cancers: options beyond anti-VEGF therapies. [27146677]
Aberrant activation of the hypoxia inducible factor (HIF) pathway causing overexpression of angiogenic genes, like vascular endothelial growth factor (VEGF), is one of the underlying causes of ocular neovascularization (NV) and metastatic cancer. Consistently, along with surgical interventions, a number of anti-VEGF agents have been approved by FDA for the treatment of ocular neovascular diseases. These anti-VEGF agents, like ranibizumab/lucentis, have revolutionized the treatment in the past decade. However, substantial vision improvement is observed only in a subset of age-related macular degeneration patients receiving ranibizumab. Further, all current therapies are associated with limitations and side effects. For example, surgeries cause tissue destruction and inflammation while anti-VEGF therapies are expensive, require repeated administration, and offer temporary relief from vascular leakage. These factors impose significant cost and treatment burdens to both the patient and society. With an aging population in most western countries with a continually increasing number of patients on lifelong treatment for these retinal diseases, the focus of ocular drug development for neovascular diseases will be to improve efficacy while reducing treatment costs. Blocking the HIF pathway, a major regulator of ocular NV and cancer, offers an appealing therapeutic strategy. Therefore, this review summarizes HIF inhibitors that have been recently evaluated for the treatment of different cancers and ischemic retinopathies.
Mesh:Angiogenesis Inducing Agents,Angiogenesis Inhibitors,Animals,Anthracyclines,Biphenyl Compounds,Cardiac Glycosides,Humans,Hypoxia-Inducible Factor 1,Indazoles,Lignans,Models, Biological,Neoplasms,Neovascularization, Pathologic,Retinal Neovascularization,Vascular Endothelial Growth Factors
Keywords:HIF inhibitors,Honokiol,Hypoxia inducible factor,Metastatic cancer,Ocular neovascularization,VEGF

Combined effect of honokiol and rosiglitazone on cell growth inhibition through enhanced G0/G1 phase arrest in hepatoma cells. [27094504]
Honokiol, a derivative extracted from the stem and bark of Magnolia officinalis, has been reported to have anticancer effects in hepatoma cells. Recently, it was found that honokiol acted as not only a retinoid X receptor (RXR) agonist but also as a peroxisome proliferator-activated receptor gamma (PPARγ) agonist. Additionally, honokiol is capable of activating PPARγ/RXR heterodimers synergistically in the presence of rosiglitazone in 3T3-L1 adipocyte and HLE human hepatoma cells. Furthermore, synthetic PPARγ agonist thiazolidinediones exhibited growth inhibition effects in hepatoma cells through PPARγ-dependent and PPARγ-independent pathways. However, the combined effects of treatment with honokiol and PPARγ agonist are unclear in hepatoma cells.
-   In this study, sulforhodamine B assay, flow cytometry, and Western blot analysis were used to examine the combined effects of honokiol and PPARγ agonist (rosiglitazone) treatment on growth inhibition in SK-Hep1 and Mahlavu hepatoma cells.
-   Honokiol or rosiglitazone treatment in hepatoma cells induced growth inhibition at high dose by sulforhodamine B assay. Moreover, we found that combined treatment with honokiol and rosiglitazone showed more effective growth inhibition in hepatoma cells than treatment with honokiol or rosiglitazone alone. Also, treatment with honokiol and rosiglitazone induced cell cycle arrest in the G0/G1 phase; increased p21; and decreased cyclin D1, cyclin E1, and Rb expression in SK-Hep1 hepatoma cells.
-   Honokiol combined with rosiglitazone showed more effective growth inhibition in hepatoma cells mediated through the regulation of G0/G1 phase-related proteins p21, cyclin D1, cyclin E1, and Rb and cell cycle progression.
Mesh:Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Carcinoma, Hepatocellular,Cell Line, Tumor,Cell Proliferation,G1 Phase Cell Cycle Checkpoints,Humans,Lignans,Liver Neoplasms,PPAR gamma,Thiazolidinediones
Keywords:PPARγ agonist,hepatocellular carcinoma,honokiol,rosiglitazone

Magnolol and honokiol exert a synergistic anti-tumor effect through autophagy and apoptosis in human glioblastomas. [27074557]
Glioblastoma (GBM) is a malignant brain tumor associated with a high mortality rate. The aim of this study is to investigate the synergistic effects of honokiol (Hono) and magnolol (Mag), extracted from Magnolia officinalis, on cytotoxicity and inhibition of human GBM tumor progression in cellular and animal models. In comparison with Hono or Mag alone, co-treatment with Hono and Mag (Hono-Mag) decreased cyclin A, D1 and cyclin-dependent kinase 2, 4, 6 significantly, leading to cell cycle arrest in U87MG and LN229 human glioma cells. In addition, phosphorylated phosphoinositide 3-kinase (p-PI3K), p-Akt, and Ki67 were decreased after Hono-Mag treatment, showing proliferation inhibition. Hono-Mag treatment also reduced p-p38 and p-JNK but elevated p-ERK expression. Besides, Hono-Mag treatment induced autophagy and intrinsic and extrinsic apoptosis. Both ERK and autophagy inhibitors enhanced Hono-Mag-induced apoptosis in LN229 cells, indicating a rescuer role of ERK. In human GBM orthotopic xenograft model, the Hono-Mag treatment inhibited the tumor progression and induced apoptosis more efficiently than Temozolomide, Hono, or Mag group. In conclusion, the Hono-Mag exerts a synergistic anti-tumor effect by inhibiting cell proliferation and inducing autophagy and apoptosis in human GBM cells. The Hono-Mag may be applied as an adjuvant therapy to improve the therapeutic efficacy of GBM treatment.
Mesh:Animals,Antineoplastic Combined Chemotherapy Protocols,Apoptosis,Autophagy,Biphenyl Compounds,Brain Neoplasms,Cell Line, Tumor,Cell Proliferation,Cell Survival,Drug Synergism,Glioblastoma,Humans,Lignans,Mice,Mice, Nude,Xenograft Model Antitumor Assays

Preclinical effects of honokiol on treating glioblastoma multiforme via G1 phase arrest and cell apoptosis. [27064011]
Our previous study showed that honokiol, a bioactive polyphenol, can traverse the blood-brain barrier and kills neuroblastoma cells.
-   In this study, we further evaluated the preclinical effects of honokiol on development of malignant glioma and the possible mechanisms.
-   Effects of honokiol on viability, caspase activities, apoptosis, and cell cycle arrest in human glioma U87 MG or U373MG cells were assayed. As to the mechanisms, levels of inactive or phosphorylated (p) p53, p21, CDK6, CDK4, cyclin D1, and E2F1 were immunodetected. Pifithrin-α (PFN-α), a p53 inhibitor, was pretreated into the cells. Finally, our in vitro findings were confirmed using intracranial nude mice implanted with U87 MG cells.
-   Exposure of human U87 MG glioma cells to honokiol decreased the cell viability. In parallel, honokiol induced activations of caspase-8, -9, and -3, apoptosis, and G1 cell cycle arrest. Treatment of U87 MG cells with honokiol increased p53 phosphorylation and p21 levels. Honokiol provoked signal-transducing downregulation of CDK6, CDK4, cyclin D1, phosphorylated (p)RB, and E2F1. Pretreatment of U87 MG cells with PFN-α significantly reversed honokiol-induced p53 phosphorylation and p21 augmentation. Honokiol-induced alterations in levels of CDK6, CDK4, cyclin D1, p-RB, and E2F1 were attenuated by PFN-α. Furthermore, honokiol could induce apoptotic insults to human U373MG glioma cells. In our in vivo model, administration of honokiol prolonged the survival rate of nude mice implanted with U87 MG cells and induced caspase-3 activation and chronological changes in p53, p21, CDK6, CDK4, cyclin D1, p-RB, and E2F1.
-   Honokiol can repress human glioma growth by inducing apoptosis and cell cycle arrest in tumor cells though activating a p53/cyclin D1/CDK6/CDK4/E2F1-dependent pathway. Our results suggest the potential of honokiol in therapies for human malignant gliomas.
Mesh:Animals,Apoptosis,Benzothiazoles,Biphenyl Compounds,Caspases,Cell Cycle Checkpoints,Cell Cycle Proteins,Cell Line, Tumor,Down-Regulation,Drug Evaluation, Preclinical,Female,G1 Phase,Glioblastoma,Humans,Lignans,Mice,Mice, Inbred BALB C,Mice, Nude,Toluene,Tumor Suppressor Protein p53
Keywords:Apoptosis,Cell cycle arrest,Honokiol,Malignant glioma,p53/CD1/CDKs/E2F1

Honokiol bis-dichloroacetate (Honokiol DCA) demonstrates activity in vemurafenib-resistant melanoma in vivo. [26871475]
The majority of human melanomas bears BRAF mutations and thus is treated with inhibitors of BRAF, such as vemurafenib. While patients with BRAF mutations often demonstrate an initial dramatic response to vemurafenib, relapse is extremely common. Thus, novel agents are needed for the treatment of these aggressive melanomas. Honokiol is a small molecule compound derived from Magnolia grandiflora that has activity against solid tumors and hematopoietic neoplasms. In order to increase the lipophilicity of honokiol, we have synthesized honokiol DCA, the dichloroacetate ester of honokiol. In addition, we synthesized a novel fluorinated honokiol analog, bis-trifluoromethyl-bis-(4-hydroxy-3-allylphenyl) methane (hexafluoro). Both compounds exhibited activity against A375 melanoma in vivo, but honokiol DCA was more active. Gene arrays comparing treated with vehicle control tumors demonstrated induction of the respiratory enzyme succinate dehydrogenase B (SDHB) by treatment, suggesting that our honokiol analogs induce respiration in vivo. We then examined its effect against a pair of melanomas, LM36 and LM36R, in which LM36R differs from LM36 in that LM36R has acquired vemurafenib resistance. Honokiol DCA demonstrated in vivo activity against LM36R (vemurafenib resistant) but not against parental LM36. Honokiol DCA and hexafluoro inhibited the phosphorylation of DRP1, thus stimulating a phenotype suggestive of respiration through mitochondrial normalization. Honokiol DCA may act in vemurafenib resistant melanomas to increase both respiration and reactive oxygen generation, leading to activity against aggressive melanoma in vivo.
Mesh:Animals,Antineoplastic Agents,Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Cell Line, Tumor,Drug Resistance, Neoplasm,Humans,Indoles,Lignans,Melanoma,Mice,Signal Transduction,Sulfonamides,Xenograft Model Antitumor Assays
Keywords:melanoma,mitochondria,reactive oxygen,vemurafenib-resistant,xenographs

Inhibition of NADPH oxidase 1 activity and blocking the binding of cytosolic and membrane-bound proteins by honokiol inhibit migratory potential of melanoma cells. [26760964]
Overexpression of NADPH oxidase 1 (Nox1) in melanoma cells is often associated with increased migration/metastasis rate. To develop effective treatment options, we have examined the effect of honokiol, a phytochemical from Magnolia plant, on the migratory potential of human melanoma cell lines (A375, Hs294t, SK-Mel119 and SK-Mel28) and assessed whether Nox1 is the target. Using an in vitro cell migration assay, we observed that treatment of different melanoma cell lines with honokiol for 24 h resulted in a dose-dependent inhibition of cell migration that was associated with reduction in Nox1 expression and reduced levels of oxidative stress. Treatment of cells with N-acetyl-L-cysteine, an anti-oxidant, also inhibited the migration of melanoma cells. Treatment of cells with diphenyleneiodonium chloride, an inhibitor of Nox1, significantly decreased the migration ability of Hs294t and SK-Mel28 cells. Further, we examined the effect of honokiol on the levels of core proteins (p22(phox) and p47(phox)) of the NADPH oxidase complex. Treatment of Hs294t and SK-Mel28 cells with honokiol resulted in accumulation of the cytosolic p47(phox) protein and decreased levels of the membrane-bound p22(phox) protein, thus blocking their interaction and inhibiting Nox1 activation. Our in vivo bioluminescence imaging data indicate that oral administration of honokiol inhibited the migration/extravasation and growth of intravenously injected melanoma cells in internal body organs, such as liver, lung and kidney in nude mice, and that this was associated with an inhibitory effect on Nox1 activity in these internal organs/tissues.
Mesh:Animals,Apoptosis,Biphenyl Compounds,Blotting, Western,Cell Membrane,Cell Movement,Cell Proliferation,Cytosol,Enzyme Inhibitors,Female,Fluorescent Antibody Technique,Humans,Lignans,Melanoma,Mice,Mice, Nude,NADPH Oxidase 1,NADPH Oxidases,Oxidative Stress,Protein Binding,Reactive Oxygen Species,Tumor Cells, Cultured,Wound Healing,Xenograft Model Antitumor Assays
Keywords:NADPH oxidase,cell migration,honokiol,imaging,melanoma

New in vitro insights on a cell death pathway induced by magnolol and honokiol in aristolochic acid tubulotoxicity. [26631295]
Aristolochic acids (AA) are nephrotoxic agents found in Aristolochia species whose consumption leads to the onset of a progressive tubulointerstitial fibrosis. This AA-nephropathy was first reported during the Belgian outbreak of the 1990's in which more than a hundred patients consumed slimming pills containing an Aristolochia species and Magnolia officinalis. The patients developed an end-stage kidney disease requiring dialysis or transplantation. Magnolol and honokiol are bioactive compounds from M. officinalis known for their potent antioxidant activity. As they can alleviate oxidative stress, we investigated their respective effects on AA-mediated tubulotoxicity using HK-2 cells. Magnolol and honokiol were able to reduce the oxidative stress associated with AA-treatment. Cytotoxicity alleviation was further investigated and overall cell viability measurements unexpectedly revealed that both compounds worsened the survival of AA-treated cells. Flow cytometry analyses of annexin V/PI stained cells indicated that the lignans efficiently prevented AA-induced apoptosis; but favored necrosis. Microscopy observations highlighted extensive vacuolization; other types of cell death, including autophagy, paraptosis or accelerated senescence were excluded. Ki-67 index and cell cycle analysis indicated that both magnolol and honokiol inhibited proliferation by blocking the cell cycle at the G1 phase; they also prevented the AA-induced G2/M arrest.
Mesh:Aristolochic Acids,Biphenyl Compounds,Cell Cycle,Cell Line,Free Radical Scavengers,Humans,Kidney Tubules,Lignans,Molecular Structure,Oxidative Stress,Picrates
Keywords:Aristolochic acids,Cell cycle,Cell death,Honokiol,Magnolol,Nephrotoxicity

Anti-biofilm and bactericidal effects of magnolia bark-derived magnolol and honokiol on Streptococcus mutans. [26600203]
Dental caries affects people of all ages and is a worldwide health concern. Streptococcus mutans is a major cariogenic bacterium because of its ability to form biofilm and induce an acidic environment. In this study, the antibacterial activities of magnolol and honokiol, the main constituents of the bark of magnolia plants, toward planktonic cell and biofilm of S. mutans were examined and compared with those of chlorhexidine. The minimal inhibitory concentrations of magnolol, honokiol and chlorhexidine for S. mutans were 10, 10 and 0.25 µg/mL, respectively. In addition, each agent showed bactericidal activity against S. mutans planktonic cells and inhibited biofilm formation in a dose- and time-dependent manner. Magnolol (50 µg/mL) had greater bactericidal activity against S. mutans biofilm than honokiol (50 µg/mL) and chlorhexidine (500 µg/mL) at 5 min after exposure, while all showed scant activity against biofilm at 30 s. Furthermore; chlorhexidine (0.5-500 µg/mL) exhibited high cellular toxicity for the gingival epithelial cell line Ca9-22 at 1 hr, whereas magnolol (50 µg/mL) and honokiol (50 µg/mL) did not. Thus; it was found that magnolol has antimicrobial activities against planktonic and biofilm cells of S. mutans. Magnolol may be a candidate for prevention and management of dental caries.
Mesh:Anti-Bacterial Agents,Biofilms,Biphenyl Compounds,Cell Line,Dose-Response Relationship, Drug,Gingiva,Humans,Lignans,Magnolia,Microbial Sensitivity Tests,Microscopy, Fluorescence,Plant Bark,Plant Extracts,Streptococcus mutans
Keywords:Streptococcus mutans,honokiol,magnolia bark,magnolol

Honokiol sensitizes breast cancer cells to TNF-α induction of apoptosis by inhibiting Nur77 expression. [26505879]
The orphan nuclear receptor Nur77 is implicated in the survival and apoptosis of cancer cells. The purpose of this study was to determine whether and how Nur77 serves to mediate the effect of the inflammatory cytokine TNF-α in cancer cells and to identify and characterize new agents targeting Nur77 for cancer therapy.
-   The effects of TNF-α on the expression and function of Nur77 were studied using in vitro and in vivo models. Nur77 expression was evaluated in tumour tissues from breast cancer patients. The anticancer effects of honokiol and its mechanism of action were assessed by in vitro, cell-based and animal studies.
-   TNF-α rapidly and potently induced the expression of Nur77 in breast cancer cells through activation of IκB kinase and JNK. Knocking down Nur77 resulted in TNF-α-dependent apoptosis, while ectopic Nur77 expression in MCF-7 cells promoted their growth in animals. Levels of Nur77 were higher in tumour tissues than the corresponding tissues surrounding the tumour in about 50% breast cancer patients studied. Our in vitro and animal studies also identified honokiol as an effective sensitizer of TNF-α-induced apoptosis by inhibiting TNF-α-induced Nur77 mRNA expression, which could be attributed to its interference of TNFR1's interaction with receptor-interacting protein 1 (RIPK1).
-   TNF-α-induced Nur77 serves as a survival factor to attenuate the death effect of TNF-α in cancer cells. With its proven human safety profile, honokiol represents a promising agent that warrants further clinical development.
Mesh:Animals,Apoptosis,Biphenyl Compounds,Breast Neoplasms,Drugs, Chinese Herbal,Female,Gene Expression Regulation, Neoplastic,HeLa Cells,Hep G2 Cells,Humans,Lignans,MCF-7 Cells,Mice,Mice, Inbred BALB C,Mice, Nude,Nuclear Receptor Subfamily 4, Group A, Member 1,Tumor Necrosis Factor-alpha,Xenograft Model Antitumor Assays

Honokiol Inhibits Constitutive and Inducible STAT3 Signaling via PU.1-Induced SHP1 Expression in Acute Myeloid Leukemia Cells. [26466521]
Constitutive and inducible activation of signal transducer and activator of transcription 3 (STAT3) signaling facilitates the carcinogenesis in most human cancers including acute myeloid leukemia (AML). Negative regulators, such as protein tyrosine phosphatases SHP1, inhibit the activated STAT3 signaling. In this study, we investigated the effect of honokiol (HNK), a constituent of Magnolia officinalis, on the STAT3 signaling. STAT3 signaling and SHP1 expression were measured by quantitative real-time PCR and western blotting in leukemic cell lines and primary AML blasts treated with HNK. HNK decreased the phosphorylated STAT3 but not the total STAT3 through increasing the expression of SHP1. In addition, HNK inhibited transcription activity of STAT3, reduced nuclear translocation of STAT3, and decreased the expression of STAT3 target genes. Knockdown of SHP1 by small hairpin RNA (shRNA) or treatment with vanadate, a protein tyrosine phosphatases inhibitor, abolished HNK-induced STAT3 inhibition, suggesting that SHP1 plays an important role in the inhibition of STAT3 signaling by HNK. Further, HNK increased the expression of transcript factor PU.1, which had been reported to activate the expression of SHP1 via binding SHP1 promoter region. Knockdown of PU.1 reversed HNK-induced upregulation of SHP1 and inactivation of STAT3 signaling. Finally, HNK increased the expression of PU.1 and SHP1 in hematopoietic progenitors isolated from patients with AML. In conclusion, our data have shown a regulatory mechanism underlying the inhibition of STAT3 signaling by HNK. Therefore, as a relative non-toxic compound, HNK may offer a therapeutic advantage in the clinical treatment for AML.
Mesh:Adult,Aged,Biphenyl Compounds,Blast Crisis,Cell Line, Tumor,Female,Gene Knockdown Techniques,Humans,Leukemia, Myeloid, Acute,Lignans,Male,Middle Aged,Phosphorylation,Protein Tyrosine Phosphatase, Non-Receptor Type 6,Proto-Oncogene Proteins,Real-Time Polymerase Chain Reaction,STAT3 Transcription Factor,Signal Transduction,Trans-Activators,Up-Regulation,Vanadates

Honokiol induces autophagy of neuroblastoma cells through activating the PI3K/Akt/mTOR and endoplasmic reticular stress/ERK1/2 signaling pathways and suppressing cell migration. [26454217]
In children, neuroblastomas are the most common and deadly solid tumor. Our previous study showed that honokiol, a small-molecule polyphenol, can traverse the blood-brain barrier and kill neuroblastoma cells. In this study, we further investigated the mechanisms of honokiol-induced insults to neuroblastoma cells. Treatment of neuroblastoma neuro-2a cells with honokiol elevated the levels of microtubule-associated protein light chain 3 (LC3)-II and induced cell autophagy in time- and concentration-dependent manners. Interestingly, pretreatment with 3-methyladenine (3-MA), an inhibitor of autophagy, led to the simultaneous attenuation of honokiol-induced cell autophagy and apoptosis but did not influence cell necrosis. As to the mechanisms, exposure of neuro-2a cells to honokiol time-dependently decreased the amount of phosphatidylinositol 3-kinase (PI3K). Sequentially, honokiol downregulated phosphorylation of protein kinase B (Akt) and mammalian target of rapamycin (mTOR) in neuro-2a cells. Furthermore, honokiol elevated the levels of glucose-regulated protein (GpR)78, an endoplasmic reticular stress (ERS)-associated protein, and amounts of intracellular reactive oxygen species (ROS). In contrast, reducing production of intracellular ROS using N-acetylcysteine, a scavenger of ROS, concurrently suppressed honokiol-induced cellular autophagy. Consequently, honokiol stimulated phosphorylation of extracellular signal-regulated kinase (ERK)1/2. However, pretreatment of neuro-2a cells with PD98059, an inhibitor of ERK1/2, lowered honokiol-induced autophagy. The effects of honokiol on inducing autophagy and apoptosis of neuroblastoma cells were further confirmed using mouse neuroblastoma NB41A3 cells as our experimental model. Fascinatingly, treatment of neuroblastoma neuro-2a and NB41A3 cells with honokiol for 12 h did not affect cell autophagy or apoptosis but caused significant suppression of cell migration. Taken together, this study showed that honokiol can induce autophagy of neuroblastoma cells and consequent apoptosis through activating the PI3K/Akt/mTOR and ERS/ROS/ERK1/2 signaling pathways and suppressing cell migration. Thus, honokiol has potential for treating neuroblastomas.
Mesh:Animals,Apoptosis,Autophagy,Biphenyl Compounds,Cell Line, Tumor,Cell Movement,Endoplasmic Reticulum Stress,Extracellular Signal-Regulated MAP Kinases,Humans,Lignans,Mice,Neuroblastoma,Phosphatidylinositol 3-Kinases,Proto-Oncogene Proteins c-akt,Reactive Oxygen Species,Signal Transduction,TOR Serine-Threonine Kinases
Keywords:Apoptosis,Autophagy,Cell migration,Honokiol,Mechanisms,Neuroblastoma

Honokiol activates LKB1-miR-34a axis and antagonizes the oncogenic actions of leptin in breast cancer. [26359358]
Leptin, a major adipocytokine produced by adipocytes, is emerging as a key molecule linking obesity with breast cancer therefore, it is important to find effective strategies to antagonize oncogenic effects of leptin to disrupt obesity-cancer axis. Here, we examine the potential of honokiol (HNK), a bioactive polyphenol from Magnolia grandiflora, as a leptin-antagonist and systematically elucidate the underlying mechanisms. HNK inhibits leptin-induced epithelial-mesenchymal-transition (EMT), and mammosphere-formation along with a reduction in the expression of stemness factors, Oct4 and Nanog. Investigating the downstream mediator(s), that direct leptin-antagonist actions of HNK; we discovered functional interactions between HNK, LKB1 and miR-34a. HNK increases the expression and cytoplasmic-localization of LKB1 while HNK-induced SIRT1/3 accentuates the cytoplasmic-localization of LKB1. We found that HNK increases miR-34a in LKB1-dependent manner as LKB1-silencing impedes HNK-induced miR-34a which can be rescued by LKB1-overexpression. Finally, an integral role of miR-34a is discovered as miR-34a mimic potentiates HNK-mediated inhibition of EMT, Zeb1 expression and nuclear-localization, mammosphere-formation, and expression of stemness factors. Leptin-antagonist actions of HNK are further enhanced by miR-34a mimic whereas miR-34a inhibitor results in inhibiting HNK's effect on leptin. These data provide evidence for the leptin-antagonist potential of HNK and reveal the involvement of LKB1 and miR-34a.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Blotting, Western,Breast Neoplasms,Cell Line,Cell Line, Tumor,Cell Proliferation,Cyclin D1,Epithelial-Mesenchymal Transition,Gene Expression Regulation, Neoplastic,Humans,Leptin,Lignans,MCF-7 Cells,Mice,MicroRNAs,Microscopy, Confocal,Protein-Serine-Threonine Kinases,RNA Interference,Reverse Transcriptase Polymerase Chain Reaction,Xenograft Model Antitumor Assays
Keywords:Honokiol,LKB1,breast cancer,leptin,miR-34a

Honokiol exhibits enhanced antitumor effects with chloroquine by inducing cell death and inhibiting autophagy in human non-small cell lung cancer cells. [26136140]
Honokiol (HNK), a potential antitumor compound, has been widely studied in recent years. It induces apoptosis and affects autophagy in cancer cells, yet the mechanism of its antitumor efficacy remains obscure. Chloroquine (CQ), an autophagy inhibitor, is often applied to sensitize antitumor drugs in clinical trials. Here, we investigated the antitumor effect of HNK or CQ alone or in combination in non-small cell lung cancer (NSCLC) cells. Using an experimental approach, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) or sulforhodamine B (SRB) was used to determine the cytotoxicity of the agents. The expression levels of proteins were detected by western blotting. Apoptosis was examined via Annexin V-FITC and PI staining. H460 cell xenografts in nude mice were used to study the effects of HNK and/or CQ in vivo. Transfection with siRNA was applied to knock down cathepsin D. The results demonstrated the enhanced effects of HNK combined with CQ on the inhibition of proliferation, induction of apoptosis in vitro and the reduction in growth in vivo. It was confirmed that HNK and/or CQ triggered apoptosis via a caspase-dependent manner. Furthermore, HNK significantly increased the expression of p62 and LC3-Ⅱ in the A549 and H460 cells and inhibited autophagy and induced apoptosis in a cathepsin D-involved manner. In conclusion, an enhanced antitumor effect was demonstrated following treatment with HNK combined with CQ by inhibiting autophagy and inducing apoptosis via a caspase-dependent and cathepsin D-involved manner. This combination may be a novel and useful antitumor approach for chemotherapy in NSCLC.
Mesh:Animals,Apoptosis,Autophagy,Biphenyl Compounds,Carcinoma, Non-Small-Cell Lung,Cell Line, Tumor,Cell Proliferation,Chloroquine,Drug Synergism,Gene Expression Regulation, Neoplastic,Humans,Lignans,Mice,Neoplasm Proteins,Xenograft Model Antitumor Assays

[Effect of honokiol on proliferation and apoptosis in HL-60 cells and its potential mechanism]. [25543478]
This study was aimed to investigate the effect of Honokiol (HNK) on proliferation and apoptosis of acute myeloid leukemia HL-60 cells and its potential mechanism. Inhibitory effect of HNK on the HL-60 cell proliferation was detected by MTT assay. Flow cytometry was used to detect the change of cell cycle and AnnexinV/PI staining was used to detect apoptosis. Western blot was applied to analyze the cell cycle protein (cyclins), cyclin-dependent kinase (CDK), P53, P21, P27, BCL-2, BCL-XL, Bax, caspase-3/9 and proteins for MAPK signal pathway. The results showed that HNK could inhibit the proliferation of HL-60 cells in time- and dose dependent ways. HNK arrested HL-60 cells in G0/G1 phase, and S phase cells decreased significantly (P < 0.05). The expression of cyclin D1, cyclin A, cyclin E and CDK2/4/6 were significantly down-regulated (P < 0.05), the expression of P53 and P21 was significantly upregulated after treating for 24 h with HNK (P < 0.05). After 24 h treatment with HNK, HL-60 cell apoptosis increased significantly with the upregulation of activated caspase-3, -9, BAX expression and the downregulation of BCL-2, BCL-XL expression. The MAPK subfamily, P38 and JNK were not significantly changed, but the expression of MEK1/2-ERK1/2 was significantly downregulated (P < 0.05). It is concluded that HNK arrestes the cells at G0/G1 phase and induces HL-60 cell apoptosis through the intervention of MEK1/2-ERK1/2 signaling pathway.
Mesh:Apoptosis,Biphenyl Compounds,Caspase 3,Cell Cycle,Cell Proliferation,Cyclin D1,Cyclin E,Cyclin-Dependent Kinase 2,HL-60 Cells,Humans,Lignans,Oncogene Proteins,Signal Transduction,bcl-2-Associated X Protein

Honokiol inhibits melanoma stem cells by targeting notch signaling. [25491779]
Melanoma is an aggressive disease with limited therapeutic options. Here, we determined the effects of honokiol (HNK), a biphenolic natural compound on melanoma cells and stemness. HNK significantly inhibited melanoma cell proliferation, viability, clonogenicity and induced autophagy. In addition, HNK significantly inhibited melanosphere formation in a dose dependent manner. Western blot analyses also demonstrated reduction in stem cell markers CD271, CD166, Jarid1b, and ABCB5. We next examined the effect of HNK on Notch signaling, a pathway involved in stem cell self-renewal. Four different Notch receptors exist in cells, which when cleaved by a series of enzymatic reactions catalyzed by Tumor Necrosis Factor-α-Converting Enzyme (TACE) and γ-secretase protein complex, results in the release of the Notch intracellular domain (NICD), which then translocates to the nucleus and induces target gene expression. Western blot analyses demonstrated that in HNK treated cells there is a significant reduction in the expression of cleaved Notch-2. In addition, there was a reduction in the expression of downstream target proteins, Hes-1 and cyclin D1. Moreover, HNK treatment suppressed the expression of TACE and γ-secretase complex proteins in melanoma cells. To confirm that suppression of Notch-2 activation is critical for HNK activity, we overexpressed NICD1, NICD2, and performed HNK treatment. NICD2, but not NICD1, partially restored the expression of Hes-1 and cyclin D1, and increased melanosphere formation. Taken together, these data suggest that HNK is a potent inhibitor of melanoma cells, in part, through the targeting of melanoma stem cells by suppressing Notch-2 signaling.
Mesh:ADAM Proteins,ADAM17 Protein,Amyloid Precursor Protein Secretases,Autophagy,Basic Helix-Loop-Helix Transcription Factors,Biomarkers, Tumor,Biphenyl Compounds,Cell Line, Tumor,Cell Proliferation,Cell Survival,Cyclin D1,Homeodomain Proteins,Humans,Lignans,Melanoma,Neoplastic Stem Cells,Receptor, Notch2,Receptors, Notch,Signal Transduction,Transcription Factor HES-1
Keywords:Cancer stem cells,Notch-1,Notch-2,autophagy,cell cycle arrest

Honokiol affects melanoma cell growth by targeting the AMP-activated protein kinase signaling pathway. [25450590]
Malignant melanoma is an aggressive form of skin cancer with limited effective therapeutic options. Melanoma research concentrates on maximizing the effect on cancer cells with minimal toxicity to normal cells. AMP-activated protein kinase (AMPK) is an important regulator of cellular energy homeostasis and has been shown to control tumor progression regulating the cell cycle, protein synthesis, and cell growth and/or survival. Honokiol (HNK) is a biphenolic compound derived from Magnolia officinalis, a plant that has been used in traditional Chinese and Japanese medicine for the treatment of various pathological conditions. Recent studies have shown that HNK has antitumor activity with relatively low toxicity. In this study, we demonstrated that the growth inhibitory effects of HNK on melanoma and melanoma cancer stem cells were mediated through the activation of AMPK and hence AMPK signaling in melanoma cells.
-   We determined the effects of HNK treatment on various melanoma cell lines. HNK-induced cell growth inhibitory effects were determined using hexosaminidase assay. Protein expression studies were done by immunoblotting. Primary spheroid assay was used to assess stemness by growing single suspension cells in ultralow attachment plates.
-   HNK is highly effective in inhibiting melanoma cells by attenuating protein kinase B/mammalian target of rapamycin and AMPK signaling. HNK showed significant inhibition of the spheroid-forming capacity of melanoma cells and, hence, stemness. HNK significantly decreased the number and size of melanospheres in a dose-dependent manner. Western blot analyses showed enhanced phosphorylation of AMPK in melanoma cells. Furthermore, HNK decreased the cellular adenosine triphosphate pool in a dose-dependent manner with maximum effects observed at 48 hours.
-   The results suggest that HNK can target melanoma cells and mark them for cell death through AMPK signaling. Further studies are warranted for developing HNK as an effective chemopreventive/therapeutic agent in melanoma.
Mesh:AMP-Activated Protein Kinases,Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Cell Cycle,Cell Line, Tumor,Cell Proliferation,Cell Survival,Humans,Immunoblotting,Lignans,Melanoma,Microscopy, Electron, Scanning,Signal Transduction,Skin Neoplasms
Keywords:AMPK,ATP/ADP,Melanoma,Metabolic pathways,Stem cells

Cytotoxicity of the bisphenolic honokiol from Magnolia officinalis against multiple drug-resistant tumor cells as determined by pharmacogenomics and molecular docking. [25442261]
A main problem in oncology is the development of drug-resistance. Some plant-derived lignans are established in cancer therapy, e.g. the semisynthetic epipodophyllotoxins etoposide and teniposide. Their activity is, unfortunately, hampered by the ATP-binding cassette (ABC) efflux transporter, P-glycoprotein. Here, we investigated the bisphenolic honokiol derived from Magnolia officinalis. P-glycoprotein-overexpressing CEM/ADR5000 cells were not cross-resistant to honokiol, but MDA-MB-231 BRCP cells transfected with another ABC-transporter, BCRP, revealed 3-fold resistance. Further drug resistance mechanisms analyzed study was the tumor suppressor TP53 and the epidermal growth factor receptor (EGFR). HCT116 p53(-/-) did not reveal resistance to honokiol, and EGFR-transfected U87.MG EGFR cells were collateral sensitive compared to wild-type cells (degree of resistance: 0.34). To gain insight into possible modes of collateral sensitivity, we performed in silico molecular docking studies of honokiol to EGFR and EGFR-related downstream signal proteins. Honokiol bound with comparable binding energies to EGFR (-7.30 ± 0.01 kcal/mol) as the control drugs erlotinib (-7.50 ± 0.30 kcal/mol) and gefitinib (-8.30 ± 0.10 kcal/mol). Similar binding affinities of AKT, MEK1, MEK2, STAT3 and mTOR were calculated for honokiol (range from -9.0 ± 0.01 to 7.40 ± 0.01 kcal/mol) compared to corresponding control inhibitor compounds for these signal transducers. This indicates that collateral sensitivity of EGFR-transfectant cells towards honokiol may be due to binding to EGFR and downstream signal transducers. COMPARE and hierarchical cluster analyses of microarray-based transcriptomic mRNA expression data of 59 tumor cell lines revealed a specific gene expression profile predicting sensitivity or resistance towards honokiol.
Mesh:ATP Binding Cassette Transporter, Sub-Family B,ATP Binding Cassette Transporter, Sub-Family G, Member 2,ATP-Binding Cassette Transporters,Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Cell Line, Tumor,Drug Resistance, Multiple,Drug Resistance, Neoplasm,Humans,Lignans,Magnolia,Molecular Docking Simulation,Neoplasm Proteins,Oligonucleotide Array Sequence Analysis,Pharmacogenetics,Receptor, Epidermal Growth Factor,Signal Transduction,Transcriptome,Tumor Suppressor Protein p53
Keywords:ABC-transporter,Cluster analysis,Kinase inhibitor,Magnolia officinalis Honokiol,Microarrays,Multidrug resistance

Honokiol inhibits lung tumorigenesis through inhibition of mitochondrial function. [25245764]
Honokiol is an important bioactive compound found in the bark of Magnolia tree. It is a nonadipogenic PPARγ agonist and capable of inhibiting the growth of a variety of tumor types both in vitro and in xenograft models. However, to fully appreciate the potential chemopreventive activity of honokiol, a less artificial model system is required. To that end, this study examined the chemopreventive efficacy of honokiol in an initiation model of lung squamous cell carcinoma (SCC). This model system uses the carcinogen N-nitroso-trischloroethylurea (NTCU), which is applied topically, reliably triggering the development of SCC within 24 to 26 weeks. Administration of honokiol significantly reduced the percentage of bronchial that exhibit abnormal lung SCC histology from 24.4% bronchial in control to 11.0% bronchial in honokiol-treated group (P = 0.01) while protecting normal bronchial histology (present in 20.5% of bronchial in control group and 38.5% of bronchial in honokiol-treated group. P = 0.004). P63 staining at the SCC site confirmed the lung SCCs phenotype. In vitro studies revealed that honokiol inhibited lung SCC cells proliferation, arrested cells at the G1-S cell-cycle checkpoint, while also leading to increased apoptosis. Our study showed that interfering with mitochondrial respiration is a novel mechanism by which honokiol changed redox status in the mitochondria, triggered apoptosis, and finally leads to the inhibition of lung SCC. This novel mechanism of targeting mitochondrial suggests honokiol as a potential lung SCC chemopreventive agent.
Mesh:Adenosine Triphosphate,Animals,Anticarcinogenic Agents,Apoptosis,Biphenyl Compounds,Bronchi,Carcinogens,Carcinoma, Squamous Cell,Carmustine,Caspase 3,Caspase 7,Cell Cycle,Cell Line, Tumor,Cell Proliferation,Female,Gene Expression Regulation, Neoplastic,Green Fluorescent Proteins,Humans,Lignans,Lung Neoplasms,Mice,Mitochondria,Neoplasm Transplantation,Oxidation-Reduction,Reactive Oxygen Species

Honokiol induces cell cycle arrest and apoptosis via inhibiting class I histone deacetylases in acute myeloid leukemia. [25187418]
Honokiol, a constituent of Magnolia officinalis, has been reported to possess potent anti-cancer activity through targeting multiple signaling pathways in numerous malignancies including acute myeloid leukemia (AML). However, the underlying mechanisms remain to be defined. Here, we report that honokiol effectively decreased enzyme activity of histone deacetylases (HDACs) and reduced the protein expression of class I HDACs in leukemic cells. Moreover, treatment with proteasome inhibitor MG132 prevented honokiol-induced degradation of class I HDACs. Importantly, honokiol increased the levels of p21/waf1 and Bax via triggering acetylation of histone in the regions of p21/waf1 and Bax promoter. Honokiol induced apoptosis, decreased activity of HDACs, and significantly inhibited the clonogenic activity of hematopoietic progenitors in bone marrow mononuclear cells from patients with AML. However, honokiol did not decrease the activity of HDACs and induce apoptosis in normal hematopoietic progenitors from unbilicial cord blood. Finally, honokiol dramatically reduced tumorigenicity in a xenograft leukemia model. Collectively, our findings demonstrate that honokiol has anti-leukemia activity through inhibiting HDACs. Thus, being a relative non-toxic agent, honokiol may serve as a novel natural agent for cancer prevention and therapy in leukemia.
Mesh:Acute Disease,Adult,Aged,Animals,Apoptosis,Biocatalysis,Biphenyl Compounds,Blotting, Western,Cell Cycle Checkpoints,Cell Line, Tumor,Cyclin-Dependent Kinase Inhibitor p21,Drugs, Chinese Herbal,Female,Histone Deacetylases,Humans,K562 Cells,Leukemia, Myeloid,Lignans,Male,Mice, Nude,Middle Aged,Proteasome Endopeptidase Complex,Reverse Transcriptase Polymerase Chain Reaction,Tumor Cells, Cultured,Xenograft Model Antitumor Assays,bcl-2-Associated X Protein

The mechanism of honokiol-induced intracellular Ca(2+) rises and apoptosis in human glioblastoma cells. [25106108]
Honokiol, an active constituent of oriental medicinal herb Magnolia officinalis, caused Ca(2+) mobilization and apoptosis in different cancer cells. In vivo, honokiol crossed the blood-brain or -cerebrospinal fluid barrier, suggesting that it may be an effective drug for the treatment of brain tumors, including glioblastoma. This study examined the effect of honokiol on intracellular Ca(2+) concentration ([Ca(2+)]i) and apoptosis in DBTRG-05MG human glioblastoma cells. Honokiol concentration-dependently induced a [Ca(2+)]i rise. The signal was decreased partially by removal of extracellular Ca(2+). Honokiol-triggered [Ca(2+)]i rise was not suppressed by store-operated Ca(2+) channel blockers (nifedipine, econazole, SK&F96365) and the protein kinase C (PKC) activator phorbol 12-myristate 13 acetate (PMA), but was inhibited by the PKC inhibitor GF109203X. GF109203X-induced inhibition was not altered by removal of extracellular Ca(2+). In Ca(2+)-free medium, pretreatment with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin (TG) or 2,5-di-tert-butylhydroquinone (BHQ) abolished honokiol-induced [Ca(2+)]i rise. Conversely, incubation with honokiol abolished TG or BHQ-induced [Ca(2+)]i rise. Inhibition of phospholipase C (PLC) with U73122 abolished honokiol-induced [Ca(2+)]i rise. Honokiol (20-80μM) reduced the cell viability, which was not reversed by prechelating cytosolic Ca(2+) with BAPTA-AM (1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester). Honokiol (20-60μM) enhanced reactive oxygen species (ROS) production, decreased mitochondrial membrane potential, released cytochrome c, and activated caspase-9/caspase-3. Together, honokiol induced a [Ca(2+)]i rise by inducing PLC-dependent Ca(2+) release from the endoplasmic reticulum and Ca(2+) entry via PKC-dependent, non store-operated Ca(2+) channels. Moreover, honokiol activated the mitochondrial pathway of apoptosis in DBTRG-05MG human glioblastoma cells.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Calcium,Calcium Signaling,Cell Line, Tumor,Cell Survival,Estrenes,Glioblastoma,Homeostasis,Humans,Lignans,Phosphodiesterase Inhibitors,Pyrrolidinones,Up-Regulation
Keywords:Apoptosis,Ca(2+),Honokiol,Human glioblastoma cells,Mitochondrial membrane potential

Honokiol activates reactive oxygen species-mediated cytoprotective autophagy in human prostate cancer cells. [25043291]
Honokiol (HNK), derived from the bark of an oriental medicinal plant (Magnolia officinalis), is a promising anticancer agent with preclinical in vitro (PC-3 and LNCaP cells) and in vivo (PC-3 xenografts) efficacy against prostate cancer. However, the mechanisms affecting anticancer response to HNK are not fully understood.
-   Human (androgen-independent PC-3 and androgen-responsive LNCaP) and murine (Myc-CaP) prostate cancer cells, and PC-3 tumor xenografts were used for various assays. Autophagy was assessed by transmission electron microscopy, immunofluorescence (LC3 puncta), and immunoblotting (LC3BII detection). Cell viability was determined by trypan blue assay. Apoptosis was quantitated by DNA fragmentation detection and Annexin V/propidium iodide assay. Reactive oxygen species (ROS) were detected by electron paramagnetic resonance spectrometry and flow cytometric/microscopic analysis of MitoSOX red fluorescence.
-   Exposure of PC-3, LNCaP, and Myc-CaP cells to pharmacologic doses of HNK resulted in autophagy induction. The PC-3 tumor xenografts from HNK-treated mice contained higher levels of LC3BII protein compared with control tumors. Cell viability inhibition and apoptosis induction resulting from HNK exposure were significantly augmented by pharmacological inhibition of autophagy using 3-methyladenine as well as RNA interference of autophagy regulator ATG5. HNK-mediated increase in levels of LC3BII protein was partially but markedly diminished in the presence of antioxidants, including N-acetylcysteine, polyethylene glycol-conjugated (PEG)-superoxide dismutase, and PEG-catalase. On the other hand, antioxidants had no impact on HNK-induced apoptosis.
-   In conclusion, the present study demonstrates, for the first time, that HNK induces ROS-mediated cytoprotective autophagy in prostate cancer cells.
Mesh:Animals,Autophagy,Biphenyl Compounds,Cell Line, Tumor,Cytoprotection,Drugs, Chinese Herbal,Humans,Lignans,Male,Mice,Mice, Transgenic,Prostatic Neoplasms,Reactive Oxygen Species
Keywords:autophagy,chemoprevention,honokiol,prostate cancer

Expression of survivin and p53 modulates honokiol-induced apoptosis in colorectal cancer cells. [24905183]
Honokiol is a small biphenolic compound, which exerts antitumor activities; however, the precise mechanism of honokiol-induced apoptosis in the human colorectal cancer cells remains unclear. Here, we show that survivin and p53 display the opposite role on the regulation of honokiol-induced apoptosis in the human colorectal cancer cells. Honokiol induced the cell death and apoptosis in various colorectal cancer cell lines. Moreover, honokiol elicited the extrinsic death receptor pathway of DR5 and caspase 8 and the intrinsic pathway of caspase 9. The common intrinsic and extrinsic downstream targets of activated caspase 3 and PARP protein cleavage were induced by honokiol. Interestingly, honokiol reduced anti-apoptotic survivin protein and gene expression. Transfection with a green fluorescent protein (GFP)-survivin-expressed vector increased the colorectal cancer cell viability and resisted the honokiol-induced apoptosis. Meantime, honokiol increased total p53 and the phosphorylated p53 proteins at Ser15 and Ser46. The p53-wild type colorectal cancer cells were exhibited greater cytotoxicity, apoptosis and survivin reduction than the p53-null cancer cells after treatment with honokiol. Together, these findings demonstrate that the existence of survivin and p53 can modulate the honokiol-induced apoptosis in the human colorectal cancer cells.
Mesh:Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Cell Line, Tumor,Cell Proliferation,Colorectal Neoplasms,Drug Resistance, Neoplasm,HCT116 Cells,Humans,Inhibitor of Apoptosis Proteins,Lignans,Signal Transduction,Tumor Suppressor Protein p53

Honokiol suppresses renal cancer cells' metastasis via dual-blocking epithelial-mesenchymal transition and cancer stem cell properties through modulating miR-141/ZEB2 signaling. [24810210]
Renal cell carcinoma (RCC) is associated with a high frequency of metastasis and only few therapies substantially prolong survival. Honokiol, isolated from Magnolia spp. bark, has been shown to exhibit pleiotropic anticancer effects in many cancer types. However, whether honokiol could suppress RCC metastasis has not been fully elucidated. In the present study, we found that honokiol suppressed renal cancer cells' metastasis via dual-blocking epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) properties. In addition, honokiol inhibited tumor growth in vivo. It was found that honokiol could upregulate miR-141, which targeted ZEB2 and modulated ZEB2 expression. Honokiol reversed EMT and suppressed CSC properties partly through the miR-141/ZEB2 axis. Our study suggested that honokiol may be a suitable therapeutic strategy for RCC treatment.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Cell Proliferation,Epithelial-Mesenchymal Transition,Homeodomain Proteins,Humans,Kidney Neoplasms,Lignans,Mice, Inbred BALB C,Mice, Nude,MicroRNAs,Neoplastic Stem Cells,Repressor Proteins,Signal Transduction,Tumor Burden,Zinc Finger E-box Binding Homeobox 2

[Honokiol combined with Gemcitabine synergistically inhibits the proliferation of human Burkitt lymphoma cells and induces their apoptosis]. [24598658]
This study was aimed to investigate the effect of Honokiol (HNK) combined with Gemcitabine (GEM) on the proliferation and apoptosis of human Burkitt lymphoma Raji cells. Cell proliferation was detected by CCK-8 method to study the role of Honokiol and Gemcitabine in Raji cells. The cell apoptosis and cell cycle status were analyzed by flow cytometry. The level of apoptosis-related protein BCL-2 was measured with Western blot. The results showed that compared with cells treated with mentioned above drugs alone, the proliferative potential of cells in combination group was significantly inhibited (P < 0.01) and the inhibition rate was related to the concentration and action time of HNK; and apoptosis rate markedly increased (P < 0.01), while most Raji cells were arrested at G0/G1 phase and decreased in S phase after treatment with combination of two drugs; the expression of BCL-2 protein decreased (P < 0.01). It is concluded that Honokiol combined Gemcitabine can synergistically inhibit the proliferation, induce cell apoptosis, and down-regulate the expression of BCL-2 in Raji cells. The possible mechanism of synergistic effect may be related with arrest of cell cycle at G0/G1 phase and downregulation of the expression of BCL-2.
Mesh:Apoptosis,Biphenyl Compounds,Burkitt Lymphoma,Cell Line, Tumor,Cell Proliferation,Deoxycytidine,Drug Synergism,Humans,Lignans,Proto-Oncogene Proteins c-bcl-2

Honokiol enhances paclitaxel efficacy in multi-drug resistant human cancer model through the induction of apoptosis. [24586249]
Resistance to chemotherapy remains a major obstacle in cancer therapy. This study aimed to evaluate the molecular mechanism and efficacy of honokiol in inducing apoptosis and enhancing paclitaxel chemotherapy in pre-clinical multi-drug resistant (MDR) cancer models, including lineage-derived human MDR (KB-8-5, KB-C1, KB-V1) and their parental drug sensitive KB-3-1 cancer cell lines. In vitro analyses demonstrated that honokiol effectively inhibited proliferation in KB-3-1 cells and the MDR derivatives (IC50 ranging 3.35 ± 0.13 µg/ml to 2.77 ± 0.22 µg/ml), despite their significant differences in response to paclitaxel (IC50 ranging 1.66 ± 0.09 ng/ml to 6560.9 ± 439.52 ng/ml). Honokiol induced mitochondria-dependent and death receptor-mediated apoptosis in MDR KB cells, which was associated with inhibition of EGFR-STAT3 signaling and downregulation of STAT3 target genes. Combined treatment with honokiol and paclitaxel synergistically augmented cytotoxicity in MDR KB cells, compared with treatment with either agent alone in vitro. Importantly, the combined treatment significantly inhibited in vivo growth of KB-8-5 tumors in a subcutaneous model. Tumor tissues from the combination group displayed a significant inhibition of Ki-67 expression and an increase in TUNEL-positive cells compared with the control group. These results suggest that targeting multidrug resistance using honokiol in combination with chemotherapy drugs may provide novel therapeutic opportunities.
Mesh:Antineoplastic Agents,Apoptosis,Biphenyl Compounds,Cell Line, Tumor,Cell Proliferation,Down-Regulation,Drug Resistance, Multiple,Drug Resistance, Neoplasm,Drug Synergism,Humans,Ki-67 Antigen,Lignans,Mitochondria,Neoplasms,Paclitaxel,Receptor, Epidermal Growth Factor,Receptors, Death Domain,STAT3 Transcription Factor,Signal Transduction

Honokiol inhibits epithelial-mesenchymal transition in breast cancer cells by targeting signal transducer and activator of transcription 3/Zeb1/E-cadherin axis. [24508063]
Epithelial-mesenchymal transition (EMT), a critical step in the acquisition of metastatic state, is an attractive target for therapeutic interventions directed against tumor metastasis. Honokiol (HNK) is a natural phenolic compound isolated from an extract of seed cones from Magnolia grandiflora. Recent studies from our lab show that HNK impedes breast carcinogenesis. Here, we provide molecular evidence that HNK inhibits EMT in breast cancer cells resulting in significant downregulation of mesenchymal marker proteins and concurrent upregulation of epithelial markers. Experimental EMT induced by exposure to TGFβ and TNFα in spontaneously immortalized nontumorigenic human mammary epithelial cells is also completely reversed by HNK as evidenced by morphological as well as molecular changes. Investigating the downstream mediator(s) that may direct EMT inhibition by HNK, we found functional interactions between HNK, Stat3, and EMT-signaling components. In vitro and in vivo analyses show that HNK inhibits Stat3 activation in breast cancer cells and tumors. Constitutive activation of Stat3 abrogates HNK-mediated activation of epithelial markers whereas inhibition of Stat3 using small molecule inhibitor, Stattic, potentiates HNK-mediated inhibition of EMT markers, invasion and migration of breast cancer cells. Mechanistically, HNK inhibits recruitment of Stat3 on mesenchymal transcription factor Zeb1 promoter resulting in decreased Zeb1 expression and nuclear translocation. We also discover that HNK increases E-cadherin expression via Stat3-mediated release of Zeb1 from E-cadherin promoter. Collectively, this study reports that HNK effectively inhibits EMT in breast cancer cells and provide evidence for a previously unrecognized cross-talk between HNK and Stat3/Zeb1/E-cadherin axis.
Mesh:Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Breast,Breast Neoplasms,Cadherins,Cell Line, Tumor,Epithelial-Mesenchymal Transition,Female,Homeodomain Proteins,Humans,Lignans,Magnolia,STAT3 Transcription Factor,Signal Transduction,Transcription Factors,Zinc Finger E-box-Binding Homeobox 1
Keywords:Breast cancer,E-cadherin,EMT,Honokiol,Stat3,Zeb1

[Honokiol inhibits the invasion and angiogenesis of U937 leukemia cells]. [24491053]
To investigate the inhibiting effect of Honokiol (HNK) on the invasion and angiogenesis in U937 leukemia cells and the molecular mechanism.
-   After treated with different concentrations of HNK, the growth inhibition rate of U937 cells was determined by MTT assay, and for the adhesion and invasion abilities were assessed using cell matrix adhesion technique and Transwell(TM); assay, respectively. VEGF, VEGFR1 and MMP-9 mRNA expression levels were detected by real-time quantitative RT-PCR (qRT-PCR). VEGF protein levels were determined by ELISA.
-   HNK could significantly inhibit the proliferation of U937 cells in a time- and dose-dependent manner. The adhesion and invasion abilities of U937 cells were suppressed after treated with a low concentration of HNK. The expressions of VEGF, VEGFR1 and MMP-9 were down-regulated by HNK in a dose-dependent manner.
-   HNK can inhibit the invasion and angiogenesis of U937 cells via down-regulating VEGF, VEGFR1 and MMP-9 expressions.
Mesh:Antineoplastic Agents,Biphenyl Compounds,Cell Adhesion,Cell Line, Tumor,Cell Proliferation,Dose-Response Relationship, Drug,Gene Expression Regulation, Neoplastic,Humans,Leukemia,Lignans,Matrix Metalloproteinase 9,Neoplasm Invasiveness,Neovascularization, Pathologic,Vascular Endothelial Growth Factor A,Vascular Endothelial Growth Factor Receptor-1

Honokiol, a low molecular weight natural product, prevents inflammatory response and cartilage matrix degradation in human osteoarthritis chondrocytes. [24375705]
Proinflammatory cytokine interleukin-1β (IL-1β) stimulates several mediators of cartilage degradation and plays an important role in the pathogenesis of osteoarthritis (OA). Honokiol, a low molecular weight natural product isolated from the Magnolia officinalis, has been shown to possess anti-inflammatory effect. Here, we used an in vitro model of cartilage inflammation to investigate the therapeutic potential of honokiol in OA. Human OA chondrocytes were cultured and pretreated with honokiol (2.5-10 µM) with or without IL-1β (10 ng/ml). Nitric oxide (NO) production was quantified by Griess reagent. Prostaglandin (PG)E2 , metalloproteinase-13 (MMP-13), and interleukin-6 (IL-6) productions were quantified by enzyme-linked immunosorbent assay. The expressions of collagen II, cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and nuclear factor κB (NF-κB)-related signaling molecules were determined by Western blotting. Our data showed that IL-1β markedly stimulated the expressions of iNOS and COX-2 and the productions of NO, PGE2 , and IL-6, which could be significantly reversed by honokiol. Honokiol could also suppress the IL-1β-triggered activation of IKK/IκBα/NF-κB signaling pathway. Moreover, honokiol significantly inhibited the IL-1β-induced MMP-13 production and collagen II reduction. Taken together, the present study suggests that honokiol may have a chondroprotective effect and may be a potential therapeutic choice in the treatment of OA patients.
Mesh:Aged,Anti-Inflammatory Agents,Biphenyl Compounds,Cell Survival,Chondrocytes,Collagen Type II,Drugs, Chinese Herbal,Humans,I-kappa B Kinase,Lignans,Magnolia,Matrix Metalloproteinase 13,Middle Aged,NF-kappa B,Osteoarthritis,Signal Transduction
Keywords:MMP-13,chondrocyte,collagen II,honokiol,osteoarthritis

Honokiol inhibits androgen receptor activity in prostate cancer cells. [24338950]
We have shown previously that honokiol (HNK), a bioactive component of the medicinal plant Magnolia officinalis, inhibits growth of human prostate cancer cells in vitro and in vivo. However, the effect of HNK on androgen receptor (AR) signaling has not been studied.
-   LNCaP, C4-2, and TRAMP-C1 cells were used for various assays. Trypan blue dye exclusion assay or clonogenic assay was performed for determination of cell viability. The effects of HNK and/or its analogs on protein levels of AR and its target gene product prostate specific antigen (PSA) were determined by western blotting. RNA interference of p53 was achieved by transient transfection. Reverse transcription-polymerase chain reaction was performed for mRNA expression of AR. Nuclear level of AR was visualized by microscopy. Apoptosis was quantified by DNA fragmentation assay or flow cytometry after Annexin V-propidium iodide staining.
-   HNK and its dichloroacetate analog (HDCA) were relatively more effective in suppressing cell viability and AR protein level than honokiol epoxide or biseugenol. Nuclear translocation of AR stimulated by a synthetic androgen (R1881) was markedly suppressed in the presence of HNK. Downregulation of AR protein resulting from HNK exposure was attributable to transcriptional repression as well as proteasomal degradation. HNK-mediated suppression of AR protein was maintained in LNCaP cells after knockdown of p53 protein. HNK-induced apoptosis was not affected by R1881 treatment.
-   The present study demonstrates, for the first time, that HNK inhibits activity of AR in prostate cancer cells regardless of the p53 status.
Mesh:Apoptosis,Biphenyl Compounds,Cell Line, Tumor,Cell Survival,Down-Regulation,Humans,Lignans,Male,Prostatic Neoplasms,Receptors, Androgen,Signal Transduction
Keywords:alternative medicine,androgen receptor,honokiol,prostate cancer

Honokiol inhibits U87MG human glioblastoma cell invasion through endothelial cells by regulating membrane permeability and the epithelial-mesenchymal transition. [24247297]
Glioblastoma is one of the most lethal and prevalent malignant human brain tumors, with aggressive proliferation and highly invasive properties. There is still no effective cure for patients with glioblastoma. Honokiol, derived from Magnolia officinalis, can cross the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB), making it a strong candidate for an effective drug for the treatment of brain tumors, including glioblastoma. In our previous study, we demonstrated that honokiol effectively induced apoptotic cell death in glioblastoma. Metastasis poses the largest problem to cancer treatment and is the primary cause of death in cancer patients. Thus, in this study, we investigated the effect of honokiol on the cell invasion process of U87MG human glioblastoma cells through brain microvascular endothelial cells (BMECs) and its possible mechanisms. Honokiol dose-dependently inhibited TNF-α-induced VCAM-1 expression in BMECs and adhesion of U87MG to BMECs. Moreover, honokiol effectively blocked U87MG invasion through BMEC-Matrigel-coated transwell membranes. Increased phosphorylation of VE-cadherin and membrane permeability by TNF-α were suppressed by honokiol in BMECs. Furthermore, we investigated the effect of honokiol on the epithelial-mesenchymal transition (EMT) in U87MG cells. Honokiol reduced the expression levels of Snail, N-cadherin and β-catenin, which are mesenchymal markers, but increased E-cadherin, an epithelial marker. In conclusion, these results suggest that honokiol inhibits metastasis by targeting the interaction between U87MG and BMECs, regulating the adhesion of U87MG to BMECs by inhibiting VCAM-1, and regulating the invasion of U87MG through BMECs by reducing membrane permeability and EMT processes of U87MG cells.
Mesh:Apoptosis,Biphenyl Compounds,Brain Neoplasms,Cell Line, Tumor,Cell Membrane Permeability,Endothelial Cells,Epithelial-Mesenchymal Transition,Gene Expression Regulation, Neoplastic,Glioblastoma,Humans,Lignans,Neoplasm Invasiveness,Vascular Cell Adhesion Molecule-1

Honokiol inhibits pathological retinal neovascularization in oxygen-induced retinopathy mouse model. [23921228]
Aberrant activation of the hypoxia inducible factor (HIF) pathway is the underlying cause of retinal neovascularization, one of the most common causes of blindness worldwide. The HIF pathway also plays critical roles during tumor angiogenesis and cancer stem cell transformation. We have recently shown that honokiol is a potent inhibitor of the HIF pathway in a number of cancer and retinal pigment epithelial cell lines. Here we evaluate the safety and efficacy of honokiol, digoxin, and doxorubicin, three recently identified HIF inhibitors from natural sources. Our studies show that honokiol has a better safety to efficacy profile as a HIF inhibitor than digoxin and doxorubicin. Further, we show for the first time that daily intraperitoneal injection of honokiol starting at postnatal day (P) 12 in an oxygen-induced retinopathy (OIR) mouse model significantly reduced retinal neovascularization at P17. Administration of honokiol also prevents the oxygen-induced central retinal vaso-obliteration, characteristic feature of the OIR model. Additionally, honokiol enhanced physiological revascularization of the retinal vascular plexuses. Since honokiol suppresses multiple pathways activated by HIF, in addition to the VEGF signaling, it may provide advantages over current treatments utilizing specific VEGF antagonists for ocular neovascular diseases and cancers.
Mesh:Animals,Antibiotics, Antineoplastic,Biphenyl Compounds,Cell Line,Digoxin,Doxorubicin,Drugs, Chinese Herbal,Enzyme Inhibitors,Humans,Hypoxia-Inducible Factor 1,Lignans,Mice,Mice, Inbred C57BL,Oxygen,Retina,Retinal Neovascularization,Transcriptional Activation
Keywords:Angiogenesis,HIF,HRE,Honokiol,Hypoxia signaling,IP,OIR,OIR-model,P,PHD,Retinopathy,Transcription regulation,VEGF,VHL,hypoxia inducible factor,hypoxia response element,intraperitoneal,oxygen-induced retinopathy,postnatal day,prolyl hydroxylation domain,vascular endothelial growth factor,von Hippel–Lindau

Anti-proliferative effect of honokiol in oral squamous cancer through the regulation of specificity protein 1. [23877711]
Honokiol (HK), a novel plant-derived natural product, is a physiologically activated compound with polyphenolic structure, and has been identified to function as an anticancer agent. It has been widely used in several diseases as a traditional medicine for a long time. We investigated whether HK could show anticancer effects on two oral squamous cell lines (OSCCs), HN-22 and HSC-4. We demonstrated that HK-treated cells showed dramatic reduction in cell growth and apoptotic cell morphologies. Intriguingly, the transcription factor specificity protein 1 (Sp1) was significantly inhibited by HK in a dose-dependent manner. Furthermore, we checked changes in cell cycle regulatory proteins and anti-apoptotic proteins at the molecular level, which are known as Sp1 target genes. The important key regulators in the cell cycle such as p27 and p21 were up-regulated by HK-mediated down-regulation of Sp1, whereas anti-apoptotic proteins including Mcl-1 and survivin were decreased, resulting in caspase-dependent apoptosis. Taken together, results from this study suggest that HK could modulate Sp1 transactivation and induce apoptotic cell death through the regulation of cell cycle and suppression of anti‑apoptotic proteins. In addition, HK may be used in cancer prevention and therapies to improve the clinical outcome as an anticancer drug.
Mesh:Antineoplastic Agents,Apoptosis,Biphenyl Compounds,Carcinoma, Squamous Cell,Cell Line, Tumor,Cell Proliferation,Down-Regulation,Gene Expression Regulation, Neoplastic,Humans,Lignans,Mouth Neoplasms,Plants,Sp1 Transcription Factor

Honokiol thwarts gastric tumor growth and peritoneal dissemination by inhibiting Tpl2 in an orthotopic model. [23828905]
Honokiol is known to suppress the growth of cancer cells; however, to date, its antiperitoneal dissemination effects have not been studied in an orthotopic mouse model. In the present study, we evaluated the antiperitoneal dissemination potential of Honokiol in an orthotopic mouse model and assessed associations with tumor growth factor-β1 (TGFβ1) and cells stimulated by a carcinogen, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Our results demonstrate that tumor growth, peritoneal dissemination and peritoneum or organ metastasis of orthotopically implanted MKN45 cells were significantly decreased in Honokiol-treated mice and that endoplasmic reticulum (ER) stress was induced. Honokiol-treated tumors showed increased epithelial signatures such as E-cadherin, cytokeratin-18 and ER stress marker. In contrast, decreased expression of vimentin, Snail and tumor progression locus 2 (Tpl2) was also noted. TGFβ1 and MNNG-induced downregulation of E-cadherin and upregulation of Tpl2 were abrogated by Honokiol treatment. The effect of Tpl2 inhibition in cancer cells or endothelial cells was associated with inactivation of CCAAT/enhancer binding protein B, nuclear factor kappa-light-chain-enhancer of activated B cell and activator protein-1 and suppression of vascular endothelial growth factor. Inhibition of Tpl2 in gastric cancer cells by small interfering RNA or pharmacological inhibitor was found to effectively reduce growth ability and vessel density in vivo. Honokiol-induced reversal of epithelial-to-mesenchymal transition (EMT) and ER stress-induced apoptosis via Tp12 may involve the paralleling processes. Taken together, our results suggest that the therapeutic inhibition of Tpl2 by Honokiol thwarts both gastric tumor growth and peritoneal dissemination by inducing ER stress and inhibiting EMT.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Blotting, Western,Cell Adhesion,Cell Movement,Cell Proliferation,Fluorescent Antibody Technique,Humans,Immunoenzyme Techniques,Immunoprecipitation,Lignans,Luciferases,MAP Kinase Kinase Kinases,Male,Mice,Mice, Inbred BALB C,Mice, Nude,Peritoneal Neoplasms,Phytotherapy,Proto-Oncogene Proteins,RNA, Messenger,Real-Time Polymerase Chain Reaction,Reverse Transcriptase Polymerase Chain Reaction,Stomach Neoplasms,Tumor Cells, Cultured

Pharmacokinetics and metabolism of 4-O-methylhonokiol in rats. [23824979]
The purpose of this study was to characterize the pharmacokinetics and metabolism of 4-O-methylhonokiol in rats. The absorption and disposition of 4-O-methylhonokiol were investigated in male Sprague-Dawley rats following a single intravenous (2 mg/kg) or oral (10 mg/kg) dose. Its metabolism was studied in vitro using rat liver microsomes and cytosol. 4-O-Methylhonokiol exhibited a high systemic plasma clearance and a large volume of distribution. The oral dose gave a peak plasma concentration of 24.1±3.3 ng/mL at 2.9±1.9 h and a low estimated bioavailability. 4-O-Methylhonokiol was rapidly metabolized and converted at least in part to honokiol in a concentration-dependent manner by cytochrome P450 in rat liver microsomes, predicting a high systemic clearance consistent with the pharmacokinetic results. It was also shown to be metabolized by glucuronidation and sulfation in rat liver microsomes and cytosol, respectively. 4-O-Methylhonokiol showed a moderate permeability with no apparent vectorial transport across Caco-2 cells, suggesting that intestinal permeation process is not likely to limit its oral absorption. Taken together, these results suggest that the rapid hepatic metabolism of 4-O-methylhonokiol could be the major reason for its high systemic clearance and low oral bioavailability.
Mesh:Absorption,Animals,Biological Availability,Biphenyl Compounds,Caco-2 Cells,Cell Membrane Permeability,Cytochrome P-450 Enzyme System,Humans,Lignans,Male,Microsomes, Liver,Rats,Rats, Sprague-Dawley

The natural product honokiol inhibits calcineurin inhibitor-induced and Ras-mediated tumor promoting pathways. [23752066]
Although calcineurin inhibitors (CNIs) are very useful in preventing allograft rejection, they can mediate a rapid progression of post-transplantation malignancies. The CNI cyclosporine A (CsA) can promote renal tumor growth through activation of the proto-oncogene ras and over-expression of the angiogenic cytokine VEGF; the ras activation also induces over-expression of the cytoprotective enzyme HO-1, which promotes survival of renal cancer cells. Here, we show that the natural product honokiol significantly inhibited CsA-induced and Ras-mediated survival of renal cancer cells through the down-regulations of VEGF and HO-1. Thus, honokiol treatment may help to prevent tumor-promoting effects of CsA in transplant patients.
Mesh:Apoptosis,Biphenyl Compounds,Calcineurin,Calcineurin Inhibitors,Cell Line, Tumor,Cell Proliferation,Cyclosporine,Down-Regulation,Gene Expression Regulation,Genes, ras,Heme Oxygenase-1,Humans,Kidney Neoplasms,Lignans,Phosphorylation,Signal Transduction,Transcriptional Activation,Transfection,Vascular Endothelial Growth Factor A,raf Kinases,ras Proteins
Keywords:HO-1,Honokiol,Ras,Renal tumor,VEGF

Honokiol inhibits non-small cell lung cancer cell migration by targeting PGE₂-mediated activation of β-catenin signaling. [23580348]
Lung cancer remains a leading cause of death due to its metastasis to distant organs. We have examined the effect of honokiol, a bioactive constituent from the Magnolia plant, on human non-small cell lung cancer (NSCLC) cell migration and the molecular mechanisms underlying this effect. Using an in vitro cell migration assay, we found that treatment of A549, H1299, H460 and H226 NSCLC cells with honokiol resulted in inhibition of migration of these cells in a dose-dependent manner, which was associated with a reduction in the levels of cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2). Celecoxib, a COX-2 inhibitor, also inhibited cell migration. Honokiol inhibited PGE2-enhanced migration of NSCLC cells, inhibited the activation of NF-κB/p65, an upstream regulator of COX-2, in A549 and H1299 cells, and treatment of cells with caffeic acid phenethyl ester, an inhibitor of NF-κB, also inhibited migration of NSCLC cells. PGE2 has been shown to activate β-catenin signaling, which contributes to cancer cell migration. Therefore, we checked the effect of honokiol on β-catenin signaling. It was observed that treatment of NSCLC cells with honokiol degraded cytosolic β-catenin, reduced nuclear accumulation of β-catenin and down-regulated matrix metalloproteinase (MMP)-2 and MMP-9, which are the down-stream targets of β-catenin and play a crucial role in cancer cell metastasis. Honokiol enhanced: (i) the levels of casein kinase-1α, glycogen synthase kinase-3β, and (ii) phosphorylation of β-catenin on critical residues Ser(45), Ser(33/37) and Thr(41). These events play important roles in degradation or inactivation of β-catenin. Treatment of celecoxib also reduced nuclear accumulation of β-catenin in NSCLC cells. FH535, an inhibitor of Wnt/β-catenin pathway, inhibited PGE2-enhanced cell migration of A549 and H1299 cells. These results indicate that honokiol inhibits non-small cell lung cancer cells migration by targeting PGE2-mediated activation of β-catenin signaling.
Mesh:Biphenyl Compounds,Carcinoma, Non-Small-Cell Lung,Cell Line, Tumor,Cell Movement,Cell Nucleus,Cyclooxygenase 2,Cyclooxygenase 2 Inhibitors,Dinoprostone,Drugs, Chinese Herbal,Gene Knockdown Techniques,Humans,Lignans,Lung Neoplasms,Neoplasm Invasiveness,RNA Interference,Signal Transduction,Sulfonamides,Transcription Factor RelA,beta Catenin

Downregulation of Sp1 is involved in honokiol-induced cell cycle arrest and apoptosis in human malignant pleural mesothelioma cells. [23525508]
Malignant pleural mesothelioma (MPM) is an extremely aggressive type of cancer and is associated with a poor patient prognosis due to its rapid progression. Novel therapeutic agents such as honokiol (HNK) improve the clinical outcomes of cancer therapy, yet the mechanisms involved have not been fully elucidated. The present study examined the regulatory effects of HNK on the growth and apoptosis of MSTO-211H mesothelioma cells and investigated its anticancer mechanism. The results revealed that HNK significantly reduced the cell viability and increased the sub-G1 population in MSTO-211H cells and suppressed the expression of the specificity protein 1 protein (Sp1). HNK reduced the transcriptional activity of Sp1 regulatory proteins, including cyclin D1, Mcl-1 and survivin, and, thus, induced apoptosis signaling pathways by increasing Bax, reducing Bid and Bcl-xl and activating caspase-3 and PARP in mesothelioma cells. The results suggest that Sp1, a novel molecular target of HNK, may be related to cell cycle arrest and apoptosis induction through the modulation of signal transduction pathways in MPM.
Mesh:Antineoplastic Agents,Apoptosis,Apoptosis Regulatory Proteins,Biphenyl Compounds,Cell Cycle Proteins,Cell Line, Tumor,Cell Proliferation,Cell Survival,Down-Regulation,Drug Screening Assays, Antitumor,G1 Phase Cell Cycle Checkpoints,Humans,Lignans,Mesothelioma,Pleural Neoplasms,Signal Transduction,Sp1 Transcription Factor

Cyclophilin D modulates cell death transition from early apoptosis to programmed necrosis induced by honokiol. [23525116]
Honokiol is a pharmacologically active small molecule with multifunctional antitumor effects. Although plenty of literature is available on honokiol-triggered apoptosis and programmed necrosis, few studies have investigated the potential existence of death mode transition from apoptosis to programmed necrosis. In the current study, we demonstrated that the necrotic cell population (PI-positive) gradually increased and the early-stage apoptotic cell population (PI-negative and AV-positive) decreased in a dose- and time-dependent manner following honokiol treatment. Furthermore, we demonstrated that these PI-positive cells were under necrotic cell death, since no late-apoptosis characteristics including conspicuous chromatin condensation or DNA ladder patterns were detected. These results demonstrated that cells suffered death mode transition from early-stage apoptosis to programmed necrosis with the increase of honokiol dose or treatment time. The protein expression of RIP3 markedly increased in parallel with HNK-triggered death mode transition, while the expression of RIP1 decreased. Cyclophilin D expression increased during cell death mode transition, and inhibition of cyclophilin D by cyclosporin A clearly blocked HNK-triggered programmed necrosis. These data indicated that honokiol-induced programmed necrosis and death mode transition are potentially RIP3‑dependent, cyclophilin D-regulated. Further results showed that blocked cyclophilin D by cyclosporin A inhibited HNK-induced necrosis, but did not affect HNK-induced RIP3 overexpression. This indicated that cyclophilin D was a potential modulator at downstream of RIP3. In conclusion, honokiol triggers a potential RIP3-dependent cell death mode transition from early-stage apoptosis to programmed necrosis, which is highly regulated by cyclophilin D.
Mesh:Apoptosis,Biphenyl Compounds,Cell Line, Tumor,Cyclophilins,Humans,Lignans,Necrosis,Receptor-Interacting Protein Serine-Threonine Kinases

Honokiol induces caspase-independent paraptosis via reactive oxygen species production that is accompanied by apoptosis in leukemia cells. [23262230]
Our previous report has shown that honokiol (HNK), a constituent of Magnolia officinalis, induces a novel form of non-apoptotic programmed cell death in human leukemia NB4 and K562 cells. In this study, we further explored the relationship between the cell death pathway and cytoplasmic vacuolization and studied the underlying mechanism of leukemia cell death mediated by honokiol. The results showed that low concentrations of honokiol activated an novel alternative cell death fitted the criteria of paraptosis, such as cytoplasmic vacuolization derived from endoplasmic reticulum swelling, lack of caspase activation, and lack of apoptotic morphology. Results further indicated that the cell death was time- and concentration-dependent. In addition, honokiol-induced paraptosis did not involve membrane blebbing, chromatin condensation and phosphatidylserine exposure at the outer of the plasma membrane. The mechanism of the cell death may be associated, at least in part, with the increased generation of reactive oxygen species. Further analysis showed that honokiol induces cell death predominantly via paraptosis and to a certain extent via apoptosis in NB4 cells, and predominantly via apoptosis and to a certain extent via paraptosis in K562 cells. These observations suggest that cell death occurs via more than one pathway in leukemia cells and targeting paraptosis may be an alternative and promising avenue for honokiol in leukemia therapy.
Mesh:Apoptosis,Biphenyl Compounds,Caspases,Cell Line, Tumor,Cell Membrane,Cytoplasm,Endoplasmic Reticulum,Humans,Leukemia,Lignans,Metabolic Networks and Pathways,Necrosis,Phosphatidylserines,Reactive Oxygen Species,Vacuoles

Modulation of P-glycoprotein expression by honokiol, magnolol and 4-O-methylhonokiol, the bioactive components of Magnolia officinalis. [23060571]
This study aimed to evaluate the effect of honokiol and its structural analogs on the functional activity and gene expression of P-glycoprotein (P-gp) in order to identify effective P-gp inhibitors from natural products which have additional health-promoting effects.
-   The interaction characteristics of honokiol, magnolol and 4-O-methylhonokiol with P-gp were determined in NCI/ADR-RES cells overexpressing P-gp.
-   All three compounds down-regulated the expression of P-gp in a concentration- and time-dependent manner, leading to 2.5- to 4.1-fold reductions of P-gp expression in NCI/ADR-RES cells. Accordingly, down-regulation of P-gp resulted in the significant enhancement of the intracellular accumulation of calcein, a P-gp substrate. Furthermore, pre-treatment with honokiol, magnolol or 4-O-methylhonokiol significantly increased the susceptibility of cancer cells to daunorubicin-induced cytotoxicity in NCI/ADR-RES cells.
-   The present study suggests that honokiol, magnolol and 4-O-methylhonokiol could be promising agents for reducing the multidrug resistance of cancer cells to anticancer drugs via the down-regulation of P-gp expression.
Mesh:ATP-Binding Cassette, Sub-Family B, Member 1,Antineoplastic Agents, Phytogenic,Antineoplastic Combined Chemotherapy Protocols,Biphenyl Compounds,Cell Line, Tumor,Daunorubicin,Down-Regulation,Drug Resistance, Multiple,Drug Resistance, Neoplasm,Humans,Lignans,Magnolia,Plant Extracts

Calpain/SHP-1 interaction by honokiol dampening peritoneal dissemination of gastric cancer in nu/nu mice. [22937084]
Honokiol, a small-molecular weight natural product, has previously been reported to activate apoptosis and inhibit gastric tumorigenesis. Whether honokiol inhibits the angiogenesis and metastasis of gastric cancer cells remains unknown.
-   We tested the effects of honokiol on angiogenic activity and peritoneal dissemination using in vivo, ex vivo and in vitro assay systems. The signaling responses in human gastric cancer cells, human umbilical vascular endothelial cells (HUVECs), and isolated tumors were detected and analyzed. In a xenograft gastric tumor mouse model, honokiol significantly inhibited the peritoneal dissemination detected by PET/CT technique. Honokiol also effectively attenuated the angiogenesis detected by chick chorioallantoic membrane assay, mouse matrigel plug assay, rat aortic ring endothelial cell sprouting assay, and endothelial cell tube formation assay. Furthermore, honokiol effectively enhanced signal transducer and activator of transcription (STAT-3) dephosphorylation and inhibited STAT-3 DNA binding activity in human gastric cancer cells and HUVECs, which was correlated with the up-regulation of the activity and protein expression of Src homology 2 (SH2)-containing tyrosine phosphatase-1 (SHP-1). Calpain-II inhibitor and siRNA transfection significantly reversed the honokiol-induced SHP-1 activity. The decreased STAT-3 phosphorylation and increased SHP-1 expression were also shown in isolated peritoneal metastatic tumors. Honokiol was also capable of inhibiting VEGF generation, which could be reversed by SHP-1 siRNA transfection.
-   Honokiol increases expression and activity of SPH-1 that further deactivates STAT3 pathway. These findings also suggest that honokiol is a novel and potent inhibitor of angiogenesis and peritoneal dissemination of gastric cancer cells, providing support for the application potential of honokiol in gastric cancer therapy.
Mesh:Animals,Apoptosis,Biphenyl Compounds,Calpain,Cell Line, Tumor,Cell Proliferation,Cells, Cultured,Human Umbilical Vein Endothelial Cells,Humans,Lignans,Mice,Neovascularization, Pathologic,Phosphorylation,Protein Tyrosine Phosphatase, Non-Receptor Type 6,RNA, Small Interfering,STAT3 Transcription Factor,Signal Transduction,Stomach Neoplasms,Up-Regulation,Xenograft Model Antitumor Assays

Honokiol exerts an anticancer effect in T98G human glioblastoma cells through the induction of apoptosis and the regulation of adhesion molecules. [22895699]
Glioblastoma is one of the most lethal and common malignant human brain tumors, with aggressive proliferation and highly invasive properties. Honokiol derived from Magnolia officinalis is able to cross the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB), suggesting a strong possibility that it could be an effective drug for the treatment of brain tumors, including glioblastoma. Thus, we investigated the effects of honokiol on the expression of adhesion molecules in TNF-α-stimulated endothelial cells, and cancer growth and invasion were determined in T98G human glioblastoma cells. Honokiol dose-dependently inhibited the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in human umbilical vein endothelial cells (HUVECs) stimulated with TNF-α for 6 h. Pretreatment with honokiol significantly reduced the adhesion of T98G cells to HUVECs. Moreover, honokiol inhibited the invasion of T98G cells, suggesting that honokiol has an anti-metastatic effect. In addition, honokiol increased the cytotoxicity of T98G cells in a dose- and time-dependent manner as assayed by MTT. TUNEL assay showed that honokiol significantly induced apoptosis in T98G cells at doses of 10 µM or more. The induction of apoptotic cell death was mediated by the downregulation of the anti-apoptotic protein Bcl-2 and the upregulation of the pro-apoptotic protein Bax. Taken together, the results of this study suggest that honokiol exerts an anticancer effect by preventing metastasis and inducing apoptotic cell death of brain tumor cells.
Mesh:Apoptosis,Biphenyl Compounds,Blood-Brain Barrier,Brain Neoplasms,Cell Adhesion,Cell Adhesion Molecules,Cell Line, Tumor,Gene Expression Regulation, Neoplastic,Glioblastoma,Human Umbilical Vein Endothelial Cells,Humans,Intercellular Adhesion Molecule-1,Lignans,Magnolia,Plant Extracts,Tumor Necrosis Factor-alpha,Vascular Cell Adhesion Molecule-1

Honokiol: a novel natural agent for cancer prevention and therapy. [22834827]
Honokiol (3',5-di-(2-propenyl)-1,1'-biphenyl-2,4'-diol) is a bioactive natural product derived from Magnolia spp. Recent studies have demonstrated anti-inflammatory, anti-angiogenic, anti-oxidative and anticancer properties of honokiol in vitro and in preclinical models. Honokiol targets multiple signaling pathways including nuclear factor kappa B (NF-κB), signal transducers and activator of transcription 3 (STAT3), epidermal growth factor receptor (EGFR) and mammalian target of rapamycin (m-TOR), which have great relevance during cancer initiation and progression. Furthermore, pharmacokinetic profile of honokiol has revealed a desirable spectrum of bioavailability after intravenous administration in animal models, thus making it a suitable agent for clinical trials. In this review, we discuss recent data describing the molecular targets of honokiol and its anti-cancer activities against various malignancies in pre-clinical models. Evaluation of honokiol in clinical trials will be the next step towards its possible human applications.
Mesh:Animals,Anti-Inflammatory Agents,Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Cell Line, Tumor,Humans,Lignans,Magnolia,Mice,NF-kappa B,Neoplasms,Plant Preparations,Rats,Receptor, Epidermal Growth Factor,STAT3 Transcription Factor,Signal Transduction,TOR Serine-Threonine Kinases

[Anti-tumor effect of tanshinone II A, tetrandrine, honokiol, curcumin, oridonin and paeonol on leukemia cell lines]. [22812238]
To study the anti-tumor effect of tanshinon II A, tetrandrine, honokiol, curcumin, oridonin and paeonol on leukemia cell lines SUP-B15, K562, CEM, HL-60 and NB4.
-   To study the anti-tumor effect of tanshinone II A, tetrandrine, honokiol, curcumin, The leukemia cell lines were exposed to the six Chinese herbal components for 96 hours. The proliferative inhibitory effects were detected with MTT and described by IC50 value.
-   Tanshinone II A inhibited the proliferations of SUP-B15, K562, CEM, HL-60 and NB4 cell lines, with HL-60 showing the least impact. Tetrandrine, honokiol, curcumin and oridonin inhibited the proliferations of SUP-B15, K562, CEM, HL-60 and NB4 cell lines and there was no significant difference between the cell lines. Paeonol did not have significant inhibitory effect on leukemia cell lines.
-   Tetrandrine, honokiol, curcumin and oridonin inhibit the proliferation of five cell lines SUP-B15, K562, CEM, HL-60, NB4, and the effects are similar, which means that their anticancer effects are quite broad. Tanshinone II A has better anti-leukemia effects on SUP-B15, K562, CEM, NB4 than on HL-60. The effect of paeonol against leukemia cell lines is poor.
Mesh:Acetophenones,Antineoplastic Agents, Phytogenic,Benzylisoquinolines,Biphenyl Compounds,Cell Line, Tumor,Cell Proliferation,Curcumin,Diterpenes, Abietane,Diterpenes, Kaurane,Drugs, Chinese Herbal,HL-60 Cells,Humans,K562 Cells,Leukemia,Lignans,Plants, Medicinal

Targeting the intrinsic inflammatory pathway: honokiol exerts proapoptotic effects through STAT3 inhibition in transformed Barrett's cells. [22744336]
One way to link chronic inflammation with cancer is through the intrinsic inflammatory pathway, in which genetic alterations that induce malignant transformation also produce a cancer-promoting, inflammatory microenvironment. Signal transducer and activator of transcription 3 (STAT3) contributes to the intrinsic inflammatory pathway in Barrett's esophagus. In human tumors, honokiol (a polyphenol in herbal teas) has growth-inhibitory and proapoptotic effects associated with suppressed activation of STAT3. We used human Barrett's epithelial and esophageal adenocarcinoma cell lines to determine effects of honokiol on cell number, necrosis, apoptosis, and anchorage-independent growth and to explore STAT3's role in those effects. We determined Ras activity and expression of phosphorylated ERK1/2, phosphorylated Akt, and phosphorylated STAT3 in the presence or absence of honokiol. Cells were infected with constitutively active Stat3-C to assess effects of honokiol-induced STAT3 inhibition on apoptosis. Honokiol decreased cell number and increased necrosis and apoptosis in transformed Barrett's cells, but not in nontransformed cells. In adenocarcinoma cells, honokiol also increased necrosis and apoptosis and decreased anchorage-independent growth. Within 30 min of honokiol treatment, transformed Barrett's cells decreased expression of phosphorylated STAT3; decreases in Ras activity and phosphorylated ERK1/2 expression were detected at 24 h. Infection with Stat3-C significantly reduced apoptosis after honokiol treatment. Honokiol causes necrosis and apoptosis in transformed Barrett's and esophageal adenocarcinoma cells, but not in nontransformed Barrett's cells, and the proapoptotic effects of honokiol are mediated by its inhibition of STAT3 signaling. These findings suggest a potential role for targeting the intrinsic inflammatory pathways as a therapeutic strategy to prevent Barrett's carcinogenesis.
Mesh:Adenocarcinoma,Antineoplastic Agents, Phytogenic,Apoptosis,Barrett Esophagus,Biphenyl Compounds,Cell Line, Tumor,Cell Transformation, Neoplastic,Esophageal Neoplasms,Humans,Lignans,STAT3 Transcription Factor,Signal Transduction

Honokiol inhibits HIF pathway and hypoxia-induced expression of histone lysine demethylases. [22580280]
Hypoxia-inducible-factor (HIF)-mediated expression of pro-angiogenic genes under hypoxic conditions is the fundamental cause of pathological neovascularization in retinal ischemic diseases and cancers. Recent studies have shown that histone lysine demethylases (KDMs) play a key role in the amplification of HIF signaling and expression of pro-angiogenic genes. Thus, the inhibitors of the HIF pathway or KDMs can have profound therapeutic value for diseases caused by pathological neovascularization. Here, we show that hypoxia-mediated expression of KDMs is a conserved process across multiple cell lines. Moreover, we report that honokiol, a biphenolic phytochemical extracted from Magnolia genus which has been used for thousands of years in the traditional Japanese and Chinese medicine, is a potent inhibitor of the HIF pathway as well as hypoxia-induced expression of KDMs in a number of cancer and retinal pigment epithelial cell lines. Further, treating the cells with honokiol leads to inhibition of KDM-mediated induction of pro-angiogenic genes (adrenomedullin and growth differentiation factor 15) under hypoxic conditions. Our results provide an evidence-based scientific explanation for therapeutic benefits observed with honokiol and warrant its further clinical evaluation for the treatment of pathological neovascularization in retinal ischemic diseases and cancers.
Mesh:Angiogenesis Inhibitors,Biphenyl Compounds,Cell Hypoxia,Cell Line,Cell Line, Tumor,Gene Expression,Histone Demethylases,Humans,Hypoxia,Hypoxia-Inducible Factor 1,Lignans,Neovascularization, Pathologic,Oxygen

In vitro growth inhibition of human cancer cells by novel honokiol analogs. [22533983]
Honokiol possesses many pharmacological activities including anti-cancer properties. Here in, we designed and synthesized honokiol analogs that block major honokiol metabolic pathway which may enhance their effectiveness. We studied their cytotoxicity in human cancer cells and evaluated possible mechanism of cell cycle arrest. Two analogs, namely 2 and 4, showed much higher growth inhibitory activity in A549 human lung cancer cells and significant increase of cell population in the G0-G1 phase. Further elucidation of the inhibition mechanism on cell cycle showed that analogs 2 and 4 inhibit both CDK1 and cyclin B1 protien levels in A549 cells.
Mesh:Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Blotting, Western,Cell Cycle,Cell Line, Tumor,Cell Proliferation,Humans,Inhibitory Concentration 50,Lignans,Lung Neoplasms,Molecular Structure,Structure-Activity Relationship

Comparative studies on the interactions of honokiol and magnolol with human serum albumin. [22480476]
In this study, the binding modes of honokiol (HK) and magnolol (MG) with human serum albumin (HSA) have been established under imitated physiological condition, which was very important to understand the pharmacokinetics and toxicity of HK or MG. The experimental results proved that the fluorescence of HSA was quenched by HK or MG through a static quenching procedure. The binding constants of HK-HSA and MG-HSA complexes were 5.304 and 263.755×10(4) L mol(-1) at 298 K, respectively. The binding process was a spontaneous molecular interaction procedure, in which the hydrophobic interaction played a major role in the formation of the HK-HSA complex, whereas, the binding interaction between MG and HSA might involve the hydrophobic interaction strongly and electrostatic interaction. In addition, the effect of HK/MG on the secondary structure of HSA was analyzed using CD, UV-vis absorption, Fourier transform infrared (FT-IR), synchronous fluorescence and three-dimensional fluorescence spectra. According to Förster no-radiation energy transfer theory, the binding distance of HSA to HK or MG was calculated to be 1.842 or 1.238 nm. Besides, the effects of common ions on the binding constants of HSA-HK/MG systems were also discussed.
Mesh:Biphenyl Compounds,Circular Dichroism,Humans,Hydrophobic and Hydrophilic Interactions,Lignans,Protein Binding,Serum Albumin,Spectrometry, Fluorescence,Spectroscopy, Fourier Transform Infrared,Static Electricity

Honokiol induces cell cycle arrest and apoptosis via inhibition of survival signals in adult T-cell leukemia. [22465179]
Honokiol, a naturally occurring biphenyl, possesses anti-neoplastic properties. We investigated activities of honokiol against adult T-cell leukemia (ATL) associated with human T-cell leukemia virus type 1 (HTLV-1).
-   Cell viability was assessed using colorimetric assay. Propidium iodide staining was performed to determine cell cycle phase. Apoptotic effects were evaluated by 7A6 detection and caspases activity. Expressions of cell cycle- and apoptosis-associated proteins were analyzed by Western blot. We investigated the efficacy of honokiol in mice harboring tumors of HTLV-1-infected T-cell origin.
-   Honokiol exhibited cytotoxic activity against HTLV-1-infected T-cell lines and ATL cells. We identified two different effects of honokiol on HTLV-1-infected T-cell lines: cell cycle inhibition and induction of apoptosis. Honokiol induced G1 cell cycle arrest by reducing the expression of cyclins D1, D2, E, CDK2, CDK4, CDK6 and c-Myc, while apoptosis was induced via reduced expression of cIAP-2, XIAP and survivin. The induced apoptosis was also associated with activation of caspases-3 and -9. In addition, honokiol suppressed the phosphorylation of IκBα, IKKα, IKKβ, STAT3, STAT5 and Akt, down-regulated JunB and JunD, and inhibited DNA binding of NF-κB, AP-1, STAT3 and STAT5. These effects resulted in the inactivation of survival signals including NF-κB, AP-1, STATs and Akt. Honokiol was highly effective against ATL in mice
-   Our data suggested that honokiol is a systemically available, non-toxic inhibitor of ATL cell growth that should be examined for potential clinical application.
-   Our findings provide a rationale for clinical evaluation of honokiol for the management of ATL.
Mesh:Adult,Animals,Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Blotting, Western,Cell Cycle Checkpoints,Cell Line, Tumor,Cell Proliferation,Cell Survival,Electrophoretic Mobility Shift Assay,Female,Humans,Leukemia-Lymphoma, Adult T-Cell,Lignans,Mice,Mice, Inbred ICR,Mice, SCID,NF-kappa B,Signal Transduction,Tumor Cells, Cultured

Honokiol activates AMP-activated protein kinase in breast cancer cells via an LKB1-dependent pathway and inhibits breast carcinogenesis. [22353783]
Honokiol, a small-molecule polyphenol isolated from magnolia species, is widely known for its therapeutic potential as an antiinflammatory, antithrombosis, and antioxidant agent, and more recently, for its protective function in the pathogenesis of carcinogenesis. In the present study, we sought to examine the effectiveness of honokiol in inhibiting migration and invasion of breast cancer cells and to elucidate the underlying molecular mechanisms.
-   Clonogenicity and three-dimensional colony-formation assays were used to examine breast cancer cell growth with honokiol treatment. The effect of honokiol on invasion and migration of breast cancer cells was evaluated by using Matrigel invasion, scratch-migration, spheroid-migration, and electric cell-substrate impedance sensing (ECIS)-based migration assays. Western blot and immunofluorescence analysis were used to examine activation of the liver kinase B1 (LKB1)-AMP-activated protein kinase (AMPK) axis. Isogenic LKB1-knockdown breast cancer cell line pairs were developed. Functional importance of AMPK activation and LKB1 overexpression in the biologic effects of honokiol was examined by using AMPK-null and AMPK-wild type (WT) immortalized mouse embryonic fibroblasts (MEFs) and isogenic LKB1-knockdown cell line pairs. Finally, mouse xenografts, immunohistochemical and Western blot analysis of tumors were used.
-   Analysis of the underlying molecular mechanisms revealed that honokiol treatment increases AMP-activated protein kinase (AMPK) phosphorylation and activity, as evidenced by increased phosphorylation of the downstream target of AMPK, acetyl-coenzyme A carboxylase (ACC) and inhibition of phosphorylation of p70S6kinase (pS6K) and eukaryotic translation initiation factor 4E binding protein 1 (4EBP1). By using AMPK-null and AMPK-WT (MEFs), we found that AMPK is required for honokiol-mediated modulation of pACC-pS6K. Intriguingly, we discovered that honokiol treatment increased the expression and cytoplasmic translocation of tumor-suppressor LKB1 in breast cancer cells. LKB1 knockdown inhibited honokiol-mediated activation of AMPK and, more important, inhibition of migration and invasion of breast cancer cells. Furthermore, honokiol treatment resulted in inhibition of breast tumorigenesis in vivo. Analysis of tumors showed significant increases in the levels of cytoplasmic LKB1 and phospho-AMPK in honokiol-treated tumors.
-   Taken together, these data provide the first in vitro and in vivo evidence of the integral role of the LKB1-AMPK axis in honokiol-mediated inhibition of the invasion and migration of breast cancer cells. In conclusion, honokiol treatment could potentially be a rational therapeutic strategy for breast carcinoma.
Mesh:AMP-Activated Protein Kinases,Adaptor Proteins, Signal Transducing,Animals,Antineoplastic Agents,Biphenyl Compounds,Breast Neoplasms,Cell Line, Tumor,Cell Movement,Cell Transformation, Neoplastic,Enzyme Activation,Female,Gene Expression,Humans,Lignans,Mice,Mice, Nude,Neoplasm Invasiveness,Phosphoproteins,Phosphorylation,Protein Processing, Post-Translational,Protein-Serine-Threonine Kinases,Proto-Oncogene Proteins c-akt,Ribosomal Protein S6 Kinases,Spheroids, Cellular,TOR Serine-Threonine Kinases,Tumor Burden,Xenograft Model Antitumor Assays

Honokiol in combination with radiation targets notch signaling to inhibit colon cancer stem cells. [22319203]
Cancer stem cells are implicated in resistance to ionizing radiation (IR) and chemotherapy. Honokiol, a biphenolic compound has been used in traditional Chinese medicine for treating various ailments. In this study, we determined the ability of honokiol to enhance the sensitivity of colon cancer stem cells to IR. The combination of honokiol and IR suppressed proliferation and colony formation while inducing apoptosis of colon cancer cells in culture. There were also reduced numbers and size of spheroids, which was coupled with reduced expression of cancer stem cell marker protein DCLK1. Flow cytometry studies confirmed that the honokiol-IR combination reduced the number of DCLK1+ cells. In addition, there were reduced levels of activated Notch-1, its ligand Jagged-1, and the downstream target gene Hes-1. Furthermore, expression of components of the Notch-1 activating γ-secretase complex, presenilin 1, nicastrin, Pen2, and APH-1 was also suppressed. On the other hand, the honokiol effects were mitigated when the Notch intracellular domain was expressed. To determine the effect of honokiol-IR combination on tumor growth in vivo, nude mice tumor xenografts were administered honokiol intraperitoneally and exposed to IR. The honokiol-IR combination significantly inhibited tumor xenograft growth. In addition, there were reduced levels of DCLK1 and the Notch signaling-related proteins in the xenograft tissues. Together, these data suggest that honokiol is a potent inhibitor of colon cancer growth that targets the stem cells by inhibiting the γ-secretase complex and the Notch signaling pathway. These studies warrant further clinical evaluation for the combination of honokiol and IR for treating colon cancers.
Mesh:Animals,Apoptosis,Biphenyl Compounds,Cell Line, Tumor,Cell Proliferation,Colonic Neoplasms,Combined Modality Therapy,Down-Regulation,Drugs, Chinese Herbal,HCT116 Cells,Humans,Immunohistochemistry,Lignans,Male,Mice,Mice, Nude,Neoplastic Stem Cells,Nitric Oxide Synthase,Signal Transduction,Transfection,Xenograft Model Antitumor Assays

[Honokiol-induced apoptosis of human non-Hodgkin lymphoma Raji cells and its  possible  mechanism]. [22126780]
To investigate the apoptosis-inducing effect of honokiol on human non-Hodgkin lymphoma Raji cells and the possible mechanism.
-   Raji cells were treated with different concentrations of honokiol, and the proliferation of the cells was detected using MTT assay. Flow cytometry was employed to analyze the cell cycle changes and apoptosis of honokiol-treated cells. Caspase 8 activity in the cells was measured by caspase 8 kit, and RT-PCR was used to detect the expression of apoptosis-related genes Bcl-2, Bad, and Bax.
-   Honokiol significantly inhibited the growth of Raji cells in a time- and dose-dependent manner, with IC(50) concentration of 17.53, 12.61, and 7.4  µg/ml at 12, 24, 48 h, respectively. Flow cytometry revealed cell cycle arrest at G0/G1 phase following honokiol treatment. The apoptosis rates of Raji cells treated with 7.5 and 15 µg/ml honokiol were significantly higher than that of the control cells [(18.24∓2.53)%, (28.44∓2.48)% vs (4.84∓1.15)%, P<0.01]. Caspase 8 activity in Raji cells was significantly enhanced by honokiol (P<0.05). The mRNA expression of the apoptosis-promoting gene Bad was significantly increased following honokiol treatment (P<0.01), while the expressions of Bcl-2 and Bax remained unchanged.
-   Honokiol can induce apoptosis in Raji cells possibly in relation to enhancement of caspase 8 activity and Bad gene expression.
Mesh:Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Burkitt Lymphoma,Caspase 8,Cell Line, Tumor,Cell Proliferation,Humans,Lignans,Lymphoma, Non-Hodgkin,bcl-Associated Death Protein

Multiple effects of Honokiol on the life cycle of hepatitis C virus. [22098176]
Honokiol, a small active molecular compound extracted from magnolia, has recently been shown to inhibit hepatitis C virus (HCV) infection in vitro.
-   This study further characterized aspects of the HCV lifecycle affected by the antiviral functions of honokiol.
-   The influence of honokiol on HCV infection, entry, translation and replication was assessed in Huh-7.5.1 cells using cell culture-derived HCV (HCVcc), HCV pseudo-type (HCVpp) and sub-genomic replicons.
-   Honokiol had strong antiviral effect against HCVcc infection at non-toxic concentrations. Combined with interferon-α, its inhibitory effect on HCVcc was more profound than that of ribavirin. Honokiol inhibited the cell entry of lentiviral particles pseudo-typed with glycoproteins from HCV genotypes 1a, 1b, and 2a, but not of the vesicular stomatitis virus. It had inefficient activity on HCV internal ribosome entry site (IRES)-translation at concentrations with significant anti-HCVcc effects. The expression levels of components of replication complex, NS3, NS5A and NS5B, were down-regulated by honokiol in a dose-dependent manner. It also inhibited HCV replication dose dependently in both genotypes 1b and 2a sub-genomic replicons.
-   Honokiol inhibits HCV infection by targeting cell entry and replication and, only at a concentration >30 μM, IRES-mediated translation of HCV life cycle. Based on its high therapeutic index (LD(50) /EC(90)  = 5.4), honokiol may be a promising drug for the treatment of HCV infection.
Mesh:Antiviral Agents,Biphenyl Compounds,Cell Line, Tumor,Dose-Response Relationship, Drug,Drug Therapy, Combination,Drugs, Chinese Herbal,Gene Expression Regulation, Viral,Genes, Reporter,Genotype,HEK293 Cells,Hepacivirus,Humans,Interferon-alpha,Lignans,Magnolia,Phenotype,Plants, Medicinal,Protein Biosynthesis,Transfection,Viral Proteins,Virus Internalization,Virus Replication

The inhibitory effect of honokiol, a natural plant product, on vestibular schwannoma cells. [22057812]
As the molecular biology of vestibular schwannoma (VS) is better understood, new means of targeting the pathways involved for intervention in schwannoma cells are being developed. Honokiol, a bioactive constituent of Magnolia officinalis, has attracted attention due to its diverse biological effects. This study was conducted to determine the inhibitory effect of honokiol on schwannoma cell proliferation.
-   HEI 193 cells were used to investigate the growth-inhibitory effects of honokiol. Cell proliferation was assessed by MTT assays. Apoptosis was measured by flow cytometry analysis and immunofluorescence staining including Hoechst 33342 and TUNEL. Western blot analysis was used to assess the potential inhibition of extracellular signal-regulated kinase (ERK) and AKT signaling by honokiol.
-   Honokiol exhibited significant antiproliferative activity in a dose-dependent manner on HEI 193 cells. Significant apoptosis was detected on schwannoma cells with 7 mg/mL(IC50) honokiol. Western blot analysis showed significant inhibition of ERK phosphorylation.
-   Honokiol, a low molecular weight natural product, inhibits cell proliferation and promotes apoptosis in schwannoma cells by targeting the ERK pathway. Our data suggest that honokiol can be evaluated as a chemotherapeutic agent for VS.
Mesh:Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Cell Proliferation,Humans,Lignans,Neuroma, Acoustic,Tumor Cells, Cultured

Antimetastatic activity of honokiol in osteosarcoma. [21935912]
Metastasizing osteosarcoma has a mean 5-year survival rate of only 20% to 30%. Therefore, novel chemotherapeutics for more effective treatment of this disease are required.
-   The antineoplastic activity of honokiol, which was demonstrated previously in numerous malignancies, was studied in vivo in C3H mice subcutaneously injected with syngeneic β-galactosidase bacterial gene (lacZ)-expressing LM8 osteosarcoma (LM8-lacZ) cells. In vitro cytotoxic effects of honokiol were investigated in 8 human and 2 murine osteosarcoma cell lines with different in vivo metastatic potential.
-   Seven days after subcutaneous flank injection of LM8-lacZ cells, daily intraperitoneal treatment of mice with 150 mg/kg honokiol reduced the number of micrometastases in the lung by 41% and reduced the number of macrometastases in the lung and liver by 69% and 80%, respectively, compared with control. Primary tumor growth was not inhibited. In osteosarcoma cell lines, honokiol inhibited the metabolic activity with a half-maximal concentration (IC(50) ) between 8.0 μg/mL and 16 μg/mL. Cyclosporin A partially reversed the inhibition of metabolic activity in LM8-lacZ cells. Cell proliferation and wound healing migration of LM8-lacZ cells were inhibited by honokiol with an IC(50) between 5.0 μg/mL and 10 μg/mL. Higher concentrations caused rapid cell death, which was distinct from necrosis, apoptosis, or autophagy but was associated with swelling of the endoplasmic reticulum, cytoplasmic vacuolation, and morphologically altered mitochondria.
-   Honokiol exhibited prominent antimetastatic activity in experimental osteosarcoma and caused rapid cell death in vitro that was unrelated to necrosis, apoptosis, or autophagy. The authors concluded that honokiol has considerable potential for the treatment of metastasizing osteosarcoma.
Mesh:Animals,Antineoplastic Agents,Apoptosis,Biphenyl Compounds,Bone Neoplasms,Cell Death,Cell Line, Tumor,Cell Proliferation,Drug Screening Assays, Antitumor,Female,Humans,Lignans,Liver Neoplasms,Lung Neoplasms,Mice,Mice, Inbred C3H,Osteosarcoma

Honokiol, a chemopreventive agent against skin cancer, induces cell cycle arrest and apoptosis in human epidermoid A431 cells. [21908486]
Honokiol is a plant lignan isolated from bark and seed cones of Magnolia officinalis. Recent studies from our laboratory indicated that honokiol pretreatment decreased ultraviolet B-induced skin cancer development in SKH-1 mice. The aim of the present investigation was to study the effects of honokiol on human epidermoid squamous carcinoma A431 cells and to elucidate possible mechanisms involved in preventing skin cancer. A431 cells were pretreated with different concentrations of honokiol for a specific time period and investigated for effects on apoptosis and cell cycle analysis. Treatment with honokiol significantly decreased cell viability and cell proliferation in a concentration- and time-dependent manner. Honokiol pretreatment at 50 μmol/L concentration induced G0/G1 cell cycle arrest significantly (P < 0.05) and decreased the percentage of cells in the S and G2/M phase. Honokiol down-regulated the expression of cyclin D1, cyclin D2, Cdk2, Cdk4 and Cdk6 proteins and up-regulated the expression of Cdk's inhibitor proteins p21 and p27. Pretreatment of A431 cells with honokiol leads to induction of apoptosis and DNA fragmentation. These findings indicate that honokiol provides its effects in squamous carcinoma cells by inducing cell cycle arrest at G0/G1 phase and apoptosis.
Mesh:Animals,Anticarcinogenic Agents,Apoptosis,Biphenyl Compounds,Carcinoma, Squamous Cell,Cell Cycle Checkpoints,Cell Line, Tumor,Cell Proliferation,Cyclin D1,Cyclin D2,Cyclin-Dependent Kinase 2,Cyclin-Dependent Kinase 4,Cyclin-Dependent Kinase 6,Cyclin-Dependent Kinase Inhibitor p21,Cyclin-Dependent Kinase Inhibitor p27,DNA Fragmentation,Gene Expression Regulation, Neoplastic,Humans,Lignans,Mice,Skin Neoplasms

Honokiol stimulates osteoblastogenesis by suppressing NF-κB activation. [21887456]
Magnolia officinalis, a component of Asian herbal teas, has long been employed in traditional Japanese and Chinese medicine to treat numerous maladies. Honokiol, a biphenolic compound, is now considered to be one of the major active ingredients of Magnolia extract, and is under intense investigation for its anti-angiogenic, anti-inflammatory, anti-tumor and neuroprotective properties. Biochemically, honokiol has been recognized to modulate the nuclear factor κ B (NF-κB) signal transduction pathway suggesting that it possesses anti-inflammatory properties. Inflammation is intimately associated with bone turnover and skeletal deterioration and consequently, anti-inflammatory drugs may hold significant promise as bone protective agents to stem bone loss in osteoporotic conditions. We and others have demonstrated that suppression of NF-κB blunts osteoclastic bone resorption, but promotes osteoblastic bone formation. Indeed previous studies have demonstrated the anti-osteoclastogenic effects of honokiol, however, activities on osteoblast differentiation and activity have yet to be investigated. In this study, we show that honokiol is a potent inducer of in vitro osteoblast differentiation by virtue of its capacity to suppress basal and tumor necrosis factor alpha (TNFα)-induced NF-κB activation and to alleviate the suppressive action of TNFα on bone morphogenetic protein (BMP)-2-induced Smad activation. Our data confirm that honokiol may have considerable promise as a dual anabolic/anti-catabolic agent for the amelioration of multiple osteoporotic diseases.
Mesh:Animals,Anti-Inflammatory Agents,Biphenyl Compounds,Blotting, Western,Bone Morphogenetic Protein 2,Bone Resorption,Cell Differentiation,Cell Line,Drugs, Chinese Herbal,Humans,Lignans,Magnolia,Mice,NF-kappa B,Osteoclasts,Osteogenesis,Osteoporosis,Signal Transduction,Smad Proteins,Tumor Necrosis Factor-alpha

Honokiol radiosensitizes colorectal cancer cells: enhanced activity in cells with mismatch repair defects. [21836060]
DNA mismatch repair is required for correcting any mismatches that are created during replication and recombination, and a defective mismatch repair system contributes to DNA damage-induced growth arrest. The colorectal cancer cell line HCT116 is known to have a mutation in the hMLH1 mismatch repair gene resulting in microsatellite instability and defective mismatch repair. Honokiol is a biphenolic compound that has been used in traditional Chinese medicine for treating various ailments including cancer. This study was designed to test the hypothesis that honokiol enhances the radiosensitivity of cancer cells with mismatch repair defect (HCT116) compared with those that are mismatch repair proficient (HCT116-CH3). We first determined that the combination of honokiol and γ-irradiation treatment resulted in dose-dependent inhibition of proliferation and colony formation in both cell lines. However, the effects were more pronounced in HCT116 cells. Similarly, the combination induced higher levels of apoptosis (caspase 3 activation, Bax to Bcl2 ratio) in the HCT116 cells compared with HCT116-CH3 cells. Cell cycle analyses revealed higher levels of dead cells in HCT116 cells. The combination treatment reduced expression of cyclin A1 and D1 and increased phosphorylated p53 in both cell lines, although there were significantly lower amounts of phosphorylated p53 in the HCT116-CH3 cells, suggesting that high levels of hMLH1 reduce radiosensitivity. These data demonstrate that honokiol is highly effective in radiosensitizing colorectal cancer cells, especially those with a mismatch repair defect.
Mesh:Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Cell Cycle,Cell Line, Tumor,Cell Proliferation,Colorectal Neoplasms,DNA Mismatch Repair,HCT116 Cells,Humans,Lignans,Radiation Tolerance,Radiation-Sensitizing Agents,Tumor Cells, Cultured

Honokiol inhibits signal transducer and activator of transcription-3 signaling, proliferation, and survival of hepatocellular carcinoma cells via the protein tyrosine phosphatase SHP-1. [21792937]
The activation of signal transducers and activators of transcription 3 (STAT3) has been closely linked with the proliferation, survival, invasion, and angiogenesis of hepatocellular carcinoma (HCC) and represents an attractive target for therapy. In the present report, we investigated whether honokiol mediates its effect through interference with the STAT3 activation pathway. The effect of honokiol on STAT3 activation, associated protein kinases, and phosphatase, STAT3-regulated gene products and apoptosis was investigated using both functional proteomics tumor pathway technology platform and different HCC cell lines. We found that honokiol inhibited both constitutive and inducible STAT3 activation in a dose- and time-dependent manner in HCC cells. The suppression was mediated through the inhibition of activation of upstream kinases c-Src, Janus-activated kinase 1, and Janus-activated kinase 2. Vanadate treatment reversed honokiol-induced down-regulation of STAT3, suggesting the involvement of a tyrosine phosphatase. Indeed, we found that honokiol induced the expression of tyrosine phosphatase SHP-1 that correlated with the down-regulation of constitutive STAT3 activation. Moreover, deletion of SHP-1 gene by siRNA abolished the ability of honokiol to inhibit STAT3 activation. The inhibition of STAT3 activation by honokiol led to the suppression of various gene products involved in proliferation, survival, and angiogenesis. Finally, honokiol inhibited proliferation and significantly potentiated the apoptotic effects of paclitaxel and doxorubicin in HCC cells. Overall, the results suggest that honokiol is a novel blocker of STAT3 activation and may have a great potential for the treatment of HCC and other cancers.
Mesh:Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Carcinoma, Hepatocellular,Caspase 3,Cell Line, Tumor,Cell Proliferation,Cell Survival,G1 Phase,Genes, Reporter,Humans,Interleukin-6,Janus Kinase 1,Janus Kinase 2,Lignans,Liver Neoplasms,Models, Biological,Poly(ADP-ribose) Polymerases,Protein Tyrosine Phosphatase, Non-Receptor Type 6,Protein-Tyrosine Kinases,Proto-Oncogene Proteins c-akt,STAT3 Transcription Factor,Signal Transduction,src-Family Kinases

Honokiol arrests cell cycle, induces apoptosis, and potentiates the cytotoxic effect of gemcitabine in human pancreatic cancer cells. [21720559]
Survival rates for patients with pancreatic cancer are extremely poor due to its asymptomatic progression to advanced and metastatic stage for which current therapies remain largely ineffective. Therefore, novel therapeutic agents and treatment approaches are desired to improve the clinical outcome. In this study, we determined the effects of honokiol, a biologically active constituent of oriental medicinal herb Magnolia officinalis/grandiflora, on two pancreatic cancer cell lines, MiaPaCa and Panc1, alone and in combination with the standard chemotherapeutic drug, gemcitabine. Honokiol exerted growth inhibitory effects on both the pancreatic cancer cell lines by causing cell cycle arrest at G₁ phase and induction of apoptosis. At the molecular level, honokiol markedly decreased the expression of cyclins (D1 and E) and cyclin-dependent kinases (Cdk2 and Cdk4), and caused an increase in Cdk inhibitors, p21 and p27. Furthermore, honokiol treatment led to augmentation of Bax/Bcl-2 and Bax/Bcl-xL ratios to favor apoptosis in pancreatic cancer cells. These changes were accompanied by enhanced cytoplasmic accumulation of NF-κB with a concomitant decrease in nuclear fraction and reduced transcriptional activity of NF-κB responsive promoter. This was associated with decreased phosphorylation of inhibitor of kappa B alpha (IκB-α) causing its stabilization and thus increased cellular levels. Importantly, honokiol also potentiated the cytotoxic effects of gemcitabine, in part, by restricting the gemcitabine-induced nuclear accumulation of NF-κB in the treated pancreatic cancer cell lines. Altogether, these findings demonstrate, for the first time, the growth inhibitory effects of honokiol in pancreatic cancer and indicate its potential usefulness as a novel natural agent in prevention and therapy.
Mesh:Apoptosis,Biphenyl Compounds,Cell Cycle,Cell Cycle Proteins,Cell Line, Tumor,Cell Nucleus,Cell Proliferation,Cell Survival,Deoxycytidine,Drug Screening Assays, Antitumor,Drug Synergism,G1 Phase,Humans,Lignans,NF-kappa B,Pancreatic Neoplasms,Protein Transport,bcl-2-Associated X Protein,bcl-X Protein

Honokiol inhibits LPS-induced maturation and inflammatory response of human monocyte-derived dendritic cells. [21660957]
Honokiol (HNK) is a phenolic compound isolated from the bark of houpu (Magnolia officinalis), a plant widely used in traditional Chinese and Japanese medicine. While substantial evidence indicates that HNK possesses anti-inflammatory activity, its effect on dendritic cells (DCs) during the inflammatory reaction remains unclear. The present study investigates how HNK affects lipopolysaccharide (LPS)-stimulated human monocyte-derived DCs. Our experimental results show that HNK inhibits the inflammatory response of LPS-induced DCs by (1) suppressing the expression of CD11c, CD40, CD80, CD83, CD86, and MHC-II on LPS-activated DCs, (2) reducing the production of TNF-α, IL-1β, IL-6, and IL-12p70 but increasing the production of IL-10 and TGF-β1 by LPS-activated DCs, (3) inhibiting the LPS-induced DC-elicited allogeneic T-cell proliferation, and (4) shifting the LPS-induced DC-driven Th1 response toward a Th2 response. Further, our results show that HNK inhibits the phosphorylation levels of ERK1/2, p38, JNK1/2, IKKα, and IκBα in LPS-activated DCs. Collectively, the findings show that the anti-inflammatory actions of HNK on LPS-induced DCs are associated with the NF-κB and mitogen-activated protein kinase (MAPK) signaling pathways.
Mesh:Biphenyl Compounds,Cell Differentiation,Cell Line,Cell Proliferation,Cell Survival,Cytokines,Dendritic Cells,Endocytosis,Enzyme Activation,Humans,Inflammation,Lignans,Lipopolysaccharides,MAP Kinase Signaling System,Mitogen-Activated Protein Kinases,Monocytes,NF-kappa B,Phenotype,Th1 Cells,Th2 Cells

Honokiol crosses BBB and BCSFB, and inhibits brain tumor growth in rat 9L intracerebral gliosarcoma model and human U251 xenograft glioma model. [21559510]
Gliosarcoma is one of the most common malignant brain tumors, and anti-angiogenesis is a promising approach for the treatment of gliosarcoma. However, chemotherapy is obstructed by the physical obstacle formed by the blood-brain barrier (BBB) and blood-cerebrospinal fluid barrier (BCSFB). Honokiol has been known to possess potent activities in the central nervous system diseases, and anti-angiogenic and anti-tumor properties. Here, we hypothesized that honokiol could cross the BBB and BCSFB for the treatment of gliosarcoma.
-   We first evaluated the abilities of honokiol to cross the BBB and BCSFB by measuring the penetration of honokiol into brain and blood-cerebrospinal fluid, and compared the honokiol amount taken up by brain with that by other tissues. Then we investigated the effect of honokiol on the growth inhibition of rat 9L gliosarcoma cells and human U251 glioma cells in vitro. Finally we established rat 9L intracerebral gliosarcoma model in Fisher 344 rats and human U251 xenograft glioma model in nude mice to investigate the anti-tumor activity.
-   We showed for the first time that honokiol could effectively cross BBB and BCSFB. The ratios of brain/plasma concentration were respectively 1.29, 2.54, 2.56 and 2.72 at 5, 30, 60 and 120 min. And about 10% of honokiol in plasma crossed BCSFB into cerebrospinal fluid (CSF). In vitro, honokiol produced dose-dependent inhibition of the growth of rat 9L gliosarcoma cells and human U251 glioma cells with IC(50) of 15.61 µg/mL and 16.38 µg/mL, respectively. In vivo, treatment with 20 mg/kg body weight of honokiol (honokiol was given twice per week for 3 weeks by intravenous injection) resulted in significant reduction of tumor volume (112.70±10.16 mm(3)) compared with vehicle group (238.63±19.69 mm(3), P = 0.000), with 52.77% inhibiting rate in rat 9L intracerebral gliosarcoma model, and (1450.83±348.36 mm(3)) compared with vehicle group (2914.17±780.52 mm(3), P = 0.002), with 50.21% inhibiting rate in human U251 xenograft glioma model. Honokiol also significantly improved the survival over vehicle group in the two models (P<0.05).
-   This study provided the first evidence that honokiol could effectively cross BBB and BCSFB and inhibit brain tumor growth in rat 9L intracerebral gliosarcoma model and human U251 xenograft glioma model. It suggested a significant strategy for offering a potential new therapy for the treatment of gliosarcoma.
Mesh:Animals,Antineoplastic Agents,Apoptosis,Biphenyl Compounds,Blood-Brain Barrier,Brain Neoplasms,Cell Line, Tumor,Cerebrospinal Fluid,Chromatography, High Pressure Liquid,Female,Glioma,Gliosarcoma,Humans,Lignans,Male,Mice,Mice, Nude,Neoplasm Transplantation,Rats,Rats, Inbred F344,Rats, Sprague-Dawley

Honokiol: an effective inhibitor of tumor necrosis factor-α-induced up-regulation of inflammatory cytokine and chemokine production in human synovial fibroblasts. [21511722]
In this study, we investigated the mechanisms underlying the anti-inflammatory effects of honokiol in tumor necrosis factor (TNF)-α-stimulated rheumatoid arthritis synovial fibroblasts (RASFs). RASFs pre-treated with honokiol (0-20 μM) were stimulated with TNF-α (20 ng/ml). The levels of prostaglandin E2 (PGE2), nitric oxide (NO), soluble intercellular adhesion molecule-1 (sICAM-1), transforming growth factor-β1 (TGF-β1), monocyte chemotactic protein-1 (MCP-1), and macrophage inflammatory protein-1α (MIP-1α) in supernatants were determined by enzyme-linked immunosorbent assay (ELISA) and Griess assay. In addition, protein expression levels of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and phosphorylated Akt, nuclear factor kappa B (NFκB), and extracellular signal-regulated kinase (ERK)1/2 were determined by western blot. The expression of NFκB-p65 was assessed by immunocytochemical analysis. TNF-α treatment significantly up-regulated the levels of PGE2, NO, sICAM-1, TGF-β1, MCP-1, and MIP-1α in the supernatants of RASFs, increased the protein expression of COX-2, iNOS, and induced phosphorylation of Akt, IκB-α, NFκB, and ERK1/2 in RASFs. TNF-α-induced expression of these molecules was inhibited in a dose-dependent manner by pre-treatment with honokiol. The inhibitory effect of honokiol on NFκB-p65 activity was also confirmed by immunocytochemical analysis. In conclusion, honokiol is a potential inhibitor of TNF-α-induced expression of inflammatory factors in RASFs, which holds promise as a potential anti-inflammatory drug.
Mesh:Biphenyl Compounds,Blotting, Western,Cells, Cultured,Chemokines,Cytokines,Enzyme-Linked Immunosorbent Assay,Fibroblasts,Fluorescent Antibody Technique,Humans,Inflammation Mediators,Lignans,Synovial Membrane,Tumor Necrosis Factor-alpha,Up-Regulation

Magnolia dealbata Zucc and its active principles honokiol and magnolol stimulate glucose uptake in murine and human adipocytes using the insulin-signaling pathway. [21511450]
Some Magnolia (Magnoliaceae) species are used for the empirical treatment of diabetes mellitus, but the antidiabetic properties of Magnolia dealbata have not yet been experimentally validated. Here we report that an ethanolic extract of Magnolia dealbata seeds (MDE) and its active principles honokiol (HK) and magnolol (MG) induced the concentration-dependent 2-NBDG uptake in murine 3T3-F442A and human subcutaneous adipocytes. In insulin-sensitive adipocytes, MDE 50 μg/ml induced the 2-NBDG uptake by 30% respect to insulin, while HK and MG, 30 μM each, did it by 50% (murine) and 40% (human). The simultaneous application of HK and MG stimulated 2-NBDG uptake by 70% in hormone-sensitive cells, on which Magnolia preparations exerted synergic effects with insulin. In insulin-resistant adipocytes, MDE, HK and MG induced 2-NBDG uptake by 57%, 80% and 96% respect to Rosiglitazone (RGZ), whereas HK and MG simultaneously applied stimulated 2-NBDG uptake more efficiently than RGZ (120%) in both murine and human adipocytes. Inhibitors of the insulin-signaling pathway abolished the glucose uptake induced by Magnolia dealbata preparations, suggesting that their antidiabetic effects are mediated by this signaling pathway. In addition, MDE, HK and MG exerted only mild to moderate proadipogenic effects on 3T3-F442A and human preadipocytes, although the combined application of HK and MG markedly increased the lipid accumulation in both cell types. In summary, Magnolia dealbata and its active principles HK and MG stimulate glucose uptake in insulin-sensitive and insulin-resistant murine and human adipocytes using the insulin signaling pathway.
Mesh:3T3 Cells,4-Chloro-7-nitrobenzofurazan,Adipocytes,Adipogenesis,Animals,Biphenyl Compounds,Cell Survival,Deoxyglucose,Drug Synergism,Glucose,Humans,Hypoglycemic Agents,Insulin,Lignans,Lipid Metabolism,Magnolia,Mice,Plant Extracts,Signal Transduction

Honokiol inhibits hypoxia-inducible factor-1 pathway. [21473672]
Hypoxia-inducible factor-1α (HIF-1α) plays a pivotal role in the reaction of a tumour to hypoxia. In this study, we examined the inhibitory effect of a natural compound, honokiol, on HIF-1α activity and tumour growth in combination with radiation.
-   The inhibitory effect of honokiol on hypoxia-responsive element (HRE) controlled luciferase activity and HIF-1α accumulations stimulated by CoCl(2), or hypoxia was examined. Effect of honokiol on HIF-1α levels within hypoxic tumour microenvironment was investigated by immunohistochemical and in vivo bioluminescent studies. The in vivo radiosensitising activity of honokiol was evaluated with subcutaneous murine colon carcinoma, CT26, xenografts of BALB/c mice treated with honokiol, radiation, or both.
-   Suppression of luciferase (luc) activity in HRE-luc stable cells by honokiol was in agreement with the results of decreased HIF-1α accumulation. In CT26-HRE-luc tumour-bearing mice, the inhibitory effect of intraperitoneally injected honokiol on HIF-1α-regulated luciferase activities induced by either CoCl(2) or radiation could be monitored non-invasively. Lastly, honokiol in combination with irradiation produced synergistic delay of CT26 tumour growth.
-   Our data suggest that honokiol can exert its anticancer activity as a HIF-1α inhibitor by reducing HIF-1α protein level and suppressing the hypoxia-related signaling pathway. The animal experiment indicates that honokiol improves the therapeutic efficacy of radiation.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Cobalt,Enzyme-Linked Immunosorbent Assay,Female,HeLa Cells,Humans,Hypoxia,Hypoxia-Inducible Factor 1,Immunohistochemistry,Lignans,Luciferases,Melanoma, Experimental,Mice,Mice, Inbred BALB C,Mice, Inbred C57BL,Neoplasm Transplantation,Neoplasms

Honokiol produces anti-neoplastic effects on melanoma cells in vitro. [21472732]
Melanoma continues to be a therapeutic challenge for the medical community owing to the scarcity of effective agents available to treat the disease. Honokiol, a traditional Chinese herb, has been proven to have anti-cancer effects in various cell types, therefore we hypothesized it may have similar cytotoxic capabilities against melanoma cells in vitro.
-   Two cell lines, SK-MEL2 and MeWo, were grown in culture and exposed to increasing doses of Honokiol. Cell proliferation, cytochrome c release into the cytosol, intra-cellular caspase activity, and mitochondrial depolarization were then evaluated after treatment with honokiol.
-   Melanoma cells in culture underwent cell death, had increased cytosolic cytochrome c, showed greater caspase activity, and demonstrated increased mitochondrial depolarization after treatment when compared to controls.
-   It appears that honokiol is an effective inhibitor of cultured human melanoma cells.
Mesh:Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Blotting, Western,Caspases,Cell Proliferation,Cytochromes c,Drugs, Chinese Herbal,Enzyme-Linked Immunosorbent Assay,Humans,In Vitro Techniques,Lignans,Melanoma,Tumor Cells, Cultured

Honokiol: a promising small molecular weight natural agent for the growth inhibition of oral squamous cell carcinoma cells. [21449214]
Honokiol (HNK) is a small organic molecule purified from magnolia species and has demonstrated anticancer activities in a variety of cancer cell lines; however, its effect on oral squamous cell carcinoma (OSCC) cells is unknown. We investigated the antitumor activities of HNK on OSCC cells in vitro for the first time. The inhibitory effects of HNK on the growth and proliferation of OSCC cells were demonstrated via in vitro 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and propidium iodide (PI) assays, and the apoptotic cells were investigated by the observation of morphological changes and detection of DNA fragmentation via PI, TdT-mediated dUTP-biotin nick end labeling (TUNEL), and DNA ladder assays, as well as flow cytometry assay. The results showed that HNK inhibited the growth and proliferation of OSCC cells in vitro in a time and dose-dependent manner. The inhibitory effect was associated with the cell apoptosis induced by HNK, evidenced by the morphological features of apoptotic cells, TUNEL-positive cells and a degradation of chromosomal DNA into small internucleosomal fragments. The study also demonstrated here that the inhibition or apoptosis mediated by 15 microg x mL(-1) or 20 microg x mL(-1) of HNK were more stronger compared with those of 20 microg x mL(-1) 5-fluorouracil (5-Fu, the control) applied to OSCC cells, when the ratio of OSCC cell numbers were measured between the treatment of different concentrations of HNK to the 5-Fu treatment for 48 h. HNK is a promising compound that can be potentially used as a novel treatment agent for human OSCC.
Mesh:Antineoplastic Agents,Antineoplastic Combined Chemotherapy Protocols,Apoptosis,Biphenyl Compounds,Carcinoma, Squamous Cell,Cell Line, Tumor,Cell Proliferation,Cell Survival,Drugs, Chinese Herbal,Flow Cytometry,Fluorouracil,Humans,In Situ Nick-End Labeling,Lignans,Magnolia,Mouth Neoplasms,Phytotherapy,Plant Extracts

In vitro metabolism and disposition of honokiol in rat and human livers. [21404278]
The biotransformation of honokiol, a major constituent of the bark of Magnolia officinalis, was investigated in rat and human livers. When isolated, rat livers were perfused with 10 µM honokiol and two metabolites, namely hydroxylated honokiol conjugated with glucuronic and sulfuric acid (M1) and honokiol monoglucuronide (M2), were quantified in bile and perfusate by high-performance liquid chromatography. The hepatic extraction ratio and clearance of honokiol was very high in rat liver (E: 0.99 ± 0.01 and 35.8 ± 0.04 mL/min, respectively) leading to very low bioavailability (F = 0.007 ± 0.001). M2 formation was also highly efficient in human liver microsomes [V(max) /K(m) = 78.1 ± 6.73 µL/(min mg)], which appeared to be catalyzed mainly by UDP-glucuronosyltransferases 1A1, A3, 1A8, and 1A10, indicating hepatic and extrahepatic glucuronidation. Monosulfation of honokiol to the minor metabolite honokiol monosulfate [V(max) /K(m) = 27.9 ± 4.33 µL/(min mg)] by human liver cytosol was less pronounced and is mediated by sulfotransferases 1A1* 1, 1A1* 2, 1A2, 1A3, 1B1, and 1E1. P450-mediated oxidation of honokiol by liver microsomes, however, was below detection limit. In summary, this study established that glucuronidation and sulfation are the main metabolic pathways for honokiol in rat and human liver, suggesting their major contribution to clearance in vivo.
Mesh:Animals,Bile,Biotransformation,Biphenyl Compounds,Chromatography, High Pressure Liquid,Cytosol,Glucuronic Acid,Humans,In Vitro Techniques,Insecta,Lignans,Liver,Magnolia,Male,Metabolic Detoxication, Phase I,Microsomes, Liver,Perfusion,Rats,Rats, Wistar,Species Specificity,Sulfuric Acids,Tissue Distribution

Honokiol, a phytochemical from Magnolia spp., inhibits breast cancer cell migration by targeting nitric oxide and cyclooxygenase-2. [21225228]
In the present study, we report the effects of honokiol, a phytochemical from Magnolia spp., on cancer cell migration capacity and the molecular mechanisms underlying these effects using breast cancer cell lines as an in vitro model. Using cell migration assays, we found that the treatment of human breast cancer cells (MCF-7) and murine mammary cancer cells (4T1) with honokiol resulted in a dose-dependent inhibition of migration of these cells, which was associated with a reduction in nitric oxide (NO) levels. The cell migration capacity was decreased in the presence of NG-nitro-L-arginine methyl ester (L-NAME), an inhibitor of NO synthase. Honokiol reduced the elevated levels of cyclic guanosine monophosphate (cGMP) in the cells, while the treatment of 4T1 cells with guanylate cyclase (GC) inhibitor 1-H-[1,2,4]oxadiaxolo[4,3-a]quinolalin-1-one (ODQ) reduced the migration of cells and the levels of cGMP. The presence of 8-bromoguanosine 3'5'-cyclic monophosphate, an analogue of cGMP, enhanced the migration of these cells, suggesting a role for GC in the migration of 4T1 cells. Honokiol also inhibited the levels of cyclooxygenase-2 (COX-2) and prostaglandin (PG) E2 in 4T1 cells. The transfection of 4T1 cells with COX-2 siRNA resulted in a reduction in cell migration. ODQ and L-NAME also decreased the levels of PGE2 in 4T1 cells suggesting a role for COX-2/PGE2 in cell migration. Moreover, honokiol inhibited the activation of nuclear factor κB (NF-κB), an upstream regulator of COX-2 and iNOS, in 4T1 cells. These results indicate that NO and COX-2 are the key targets of honokiol in the inhibition of breast cancer cell migration, an essential step in invasion and metastasis.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Breast Neoplasms,Carcinoma,Cell Line, Tumor,Cell Movement,Cyclooxygenase 2,Drug Evaluation, Preclinical,Drugs, Chinese Herbal,Female,Humans,Lignans,Magnolia,Mice,Models, Biological,Molecular Targeted Therapy,Nitric Oxide,Phytotherapy

Inhibitory effects of honokiol on lipopolysaccharide-induced cellular responses and signaling events in human renal mesangial cells. [21147091]
Honokiol has been shown to possess a lot of pharmacologic benefits, including antioxidative, antiangiogenic and antineoplastic effects. In the present study, we investigated the anti-inflammatory effects of honokiol and the signaling mechanisms involved in lipopolysaccharide (LPS)-induced conditions in human renal mesangial cells (HRMCs). Honokiol did not significantly change HRMC viability when used at a concentration of <20 μmol/l but markedly altered cell viability at concentrations of >40 μmol/l. In this study, LPS treatment led to a marked upregulation of the levels of IL-1β, IL-18, TNF-α, TGF-β1, CCL2, CCL3, and CCL5 in HRMCs. The expression of COX-2, iNOS, and their products PGE(2) and NO also increased. The upregulation of these molecules was significantly abolished by honokiol in a dose-dependent manner. Moreover, honokiol almost completely reversed IL-1β, CCL3, and NO expression at 10 μmol/l, and IL-18, TNF-α, TGF-β1, and COX-2 expression at 20 μmol/l. In addition, phospho-NF-κB p65 at Ser536, phospho-Akt, and phospho-p42/44 were dramatically suppressed by honokiol in LPS-treated HRMCs. These results indicate that honokiol can inhibit the LPS-induced expression of inflammatory cytokines and mediators in HRMCs. The anti-inflammatory mechanisms of honokiol are partly due to the suppression of the phospho-NF-κB p65, phospho-Akt and phospho-p42/44 pathways.
Mesh:Anti-Inflammatory Agents,Biphenyl Compounds,Cell Survival,Cyclooxygenase 2,Cytokines,Dose-Response Relationship, Drug,Gene Expression Regulation,Humans,Inflammation Mediators,Lignans,Lipopolysaccharides,Mesangial Cells,Nitric Oxide Synthase Type II,Phosphorylation,Signal Transduction

Honokiol inhibits H(2)O(2)-induced apoptosis in human lens epithelial cells via inhibition of the mitogen-activated protein kinase and Akt pathways. [20965163]
Oxidative stress-induced apoptosis in lens epithelial cells plays an important role in cataract formation, and its prevention may be of therapeutic interest. This study was performed to investigate the protective effect and mechanisms of honokiol on H(2)O(2)-induced apoptosis in human lens epithelial (HLE) cells. HLE cells (SRA01-04) were pretreated with honokiol at concentrations of 5μM, 10μM and 20μM before 50μM H(2)O(2) treatment. The results demonstrated that pretreatment of honokiol inhibited the activation of caspase-3 and caspase-9 and downregulated the expression of Bcl-2. Mechanistically, honokiol suppressed H(2)O(2)-induced phosphorylation of ERK1/2, p38 mitogen-activated protein kinase (MAPK), JNK and Akt. Honokiol also inhibited H(2)O(2)-induced nuclear factor-κB (NF-κB)/p65 phosphorylation and translocation in HLE cells. These results demonstrate that honokiol suppresses H(2)O(2)-induced HLE cell apoptosis via interference with the MAPKs, Akt and NF-κB signaling, suggesting that honokiol might have a potential effect against cataract formation.
Mesh:Apoptosis,Biphenyl Compounds,Caspase 3,Caspase 9,Cell Line,Down-Regulation,Enzyme Activation,Epithelial Cells,Humans,Hydrogen Peroxide,Lens, Crystalline,Lignans,Mitogen-Activated Protein Kinases,Protein Transport,Proto-Oncogene Proteins c-akt,Proto-Oncogene Proteins c-bcl-2,Signal Transduction,Transcription Factor RelA,Up-Regulation

Honokiol inhibits gastric tumourigenesis by activation of 15-lipoxygenase-1 and consequent inhibition of peroxisome proliferator-activated receptor-gamma and COX-2-dependent signals. [20649594]
Peroxisome proliferator-activated receptor-gamma (PPAR-gamma), COX-2 and 15-lipoxygenase (LOX)-1 have been shown to be involved in tumour growth. However, the roles of PPAR-gamma, COX-2 or 15-LOX-1 in gastric tumourigenesis remain unclear. Here, we investigate the role of 15-LOX-1 induction by honokiol, a small-molecular weight natural product, in PPAR-gamma and COX-2 signalling during gastric tumourigenesis.
-   Human gastric cancer cell lines (AGS, MKN45, N87 and SCM-1) were cultured with or without honokiol. Gene and protein expressions were analysed by RT-PCR and Western blotting respectively. Small interfering RNAs (siRNAs) for COX-2, PPAR-gamma and 15-LOX-1 were used to interfere with the expressions of these genes. A xenograft gastric tumour model in mouse was used for in vivo study.
-   PPAR-gamma and COX-2 proteins were highly expressed in gastric cancer cells. Inhibitors, or siRNA for COX-2 or PPAR-gamma, significantly decreased cell viability. Honokiol markedly inhibited PPAR-gamma and COX-2 expressions in gastric cancer cells and tumours of xenograft mice, and induced apoptosis and cell death. Honokiol markedly activated cellular 15-LOX-1 expression and 13-S-hydroxyoctadecadienoic acid (a primary product of 15-LOX-1 metabolism of linoleic acid) production. 15-LOX-1 siRNA could reverse the honokiol-induced down-regulation of PPAR-gamma and COX-2, and cell apoptosis. 15-LOX-1 was markedly induced in tumours of xenograft mice treated with honokiol.
-   These findings suggest that induction of 15-LOX-1-mediated down-regulation of a PPAR-gamma and COX-2 pathway by honokiol may be a promising therapeutic strategy for gastric cancer.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Apoptosis,Arachidonate 15-Lipoxygenase,Biphenyl Compounds,Blotting, Western,Cell Line, Tumor,Cell Survival,Cyclooxygenase 2,Cyclooxygenase Inhibitors,Dose-Response Relationship, Drug,Enzyme Activation,Gene Expression Regulation, Enzymologic,Gene Expression Regulation, Neoplastic,Humans,Lignans,Linoleic Acids,Male,Mice,Mice, Inbred BALB C,Mice, Nude,PPAR gamma,RNA Interference,Reverse Transcriptase Polymerase Chain Reaction,Signal Transduction,Stomach Neoplasms,Time Factors,Tumor Burden,Xenograft Model Antitumor Assays

Honokiol increases ABCA1 expression level by activating retinoid X receptor beta. [20606297]
ABCA1, a member of the ATP-binding cassette transporter family, regulates high-density lipoprotein (HDL) metabolism and reverses cholesterol transport. Its expression is upregulated mainly by the activation of the liver X receptor (LXR), retinoid X receptor (RXR), and peroxisome proliferator-activated receptors (PPARs). To identify natural compounds that can upregulate ABCA1 expression, we developed a reporter assay using U251-MG (human glioma cell line) cells that stably express a human ABCA1 promoter-luciferase and performed a cell-based high-throughput screening of 118 natural compounds. Using this system, we identified honokiol, a compound extracted from Magnolia officinalis, as an activator of the ABCA1 promoter. We found that honokiol also increased ABCA1 mRNA and protein expression levels in a dose-dependent manner in U251-MG cells without significant cell death and also increased ABCA1, ABCG1 and apolipoprotein E (apoE) expression levels in THP-1 macrophages. PPAR antagonists did not diminish the induction of ABCA1 expression by honokiol in U251-MG cells. Cotreatment of the cells with honokiol and T0901317 (synthetic LXR ligand) further increased the ABCA1 expression level, whereas cotreatment with 9-cis retinoic acid had no additive effect compared with treatment with honokiol alone. We also found that honokiol has binding affinity to RXRbeta. In this study, we identified for the first time honokiol as an upregulator of ABCA1 expression, which is mediated by the binding of honokiol to RXRbeta as a ligand.
Mesh:ATP Binding Cassette Transporter 1,ATP-Binding Cassette Transporters,Base Sequence,Biphenyl Compounds,Blotting, Western,Cell Line, Tumor,DNA Primers,Humans,In Situ Nick-End Labeling,Ligands,Lignans,Promoter Regions, Genetic,Retinoid X Receptor beta

Modulation of multidrug resistance p-glycoprotein activity by flavonoids and honokiol in human doxorubicin- resistant sarcoma cells (MES-SA/DX-5): implications for natural sedatives as chemosensitizing agents in cancer therapy. [20487633]
Multidrug resistance (MDR) in cancer cells is often caused by the high expression of the plasma membrane drug transporter P-glycoprotein (Pgp) associated with an elevated intracellular glutathione (GSH) content in various human tumors. Several chemosensitizers reverse MDR but have significant toxicities. Sedatives are often used to control anxiety and depression in cancer patients. In this in vitro study we investigated the effects of three plant derived sedatives such as apigenin (Api), fisetin (Fis), flavonoids and honokiol (Hnk) on Pgp activity and cellular GSH content in order to evaluate their potential use as chemosensitizing agents in anticancer chemotherapy. Human doxorubicin (doxo) resistant uterine sarcoma cells (MES-SA/Dx5) that overexpress Pgp, were treated with each sedative alone (10 microM) or in combination with different doxo concentrations (2-8 microM). We measured the intracellular accumulation and cytotoxicity of doxo (MTT assay), the cellular GSH content (GSH assay) and ROS production (DFC-DA assay), in comparison with verapamil (Ver), a specific inhibitor for Pgp, used as reference molecule. We found that exposure at 2 and 8 microM doxo concentrations in the presence of Api, Fis and Hnk enhanced significantly doxo accumulation by 29+/-3.3, 20+/-4.8, 24+/-6.6 percent and 14+/-1.7, 8.3+/-4.2, 10.7+/-3.1 percent, respectively, when compared with doxo alone. These results were consistent with the increase of sensitivity towards doxo in MES-SA/Dx5, resulting in 1.7, 1.2, 1.4-fold and 1.2, 1.0 and 1.1-fold increases, respectively. Moreover, treatment with Api decreased markedly cellular GSH content (18 percent) and increased ROS production (greater than 20 percent) on MES-SA/Dx5 cells, while a significant reduction in ROS levels was observed in Hnk and Fis treated cells, when compared to untreated control. Our in vitro findings provide a rationale for innovative clinical trials to assess the use of natural sedatives or their derivatives as potential adjuvants to anticancer treatment for overcoming multidrug resistance Pgp-mediated in cancer patients.
Mesh:Antibiotics, Antineoplastic,Biphenyl Compounds,Cell Division,Cell Line, Tumor,Cell Survival,Doxorubicin,Drug Resistance, Multiple,Drug Resistance, Neoplasm,Drugs, Chinese Herbal,Flavonoids,Glutathione,Humans,Hypnotics and Sedatives,Lignans,Reactive Oxygen Species,Sarcoma

Honokiol inhibits epidermal growth factor receptor signaling and enhances the antitumor effects of epidermal growth factor receptor inhibitors. [20388852]
This study aimed to investigate the utility of honokiol, a naturally occurring compound, in the treatment of head and neck squamous cell carcinoma (HNSCC) as well as its ability to target the epidermal growth factor receptor (EGFR), a critical therapeutic target in HNSCC, and to enhance the effects of other EGFR-targeting therapies.
-   Human HNSCC cell lines and the xenograft animal model of HNSCC were used to test the effects of honokiol treatment.
-   Honokiol was found to inhibit growth in human HNSCC cell lines, with 50% effective concentration (EC(50)) values ranging from 3.3 to 7.4 micromol/L, and to induce apoptosis, as shown through Annexin V staining. These effects were associated with inhibition of EGFR signaling, including downstream inhibition of mitogen-activated protein kinase, Akt, and signal transducer and activator of transcription 3 (STAT3), and expression of STAT3 target genes, Bcl-X(L) and cyclin D1. Furthermore, honokiol enhanced the growth inhibitory and anti-invasion activity of the EGFR-targeting agent erlotinib. Although HNSCC xenograft models did not show significant inhibition of in vivo tumor growth with honokiol treatment alone, the combination of honokiol plus cetuximab, a Food and Drug Administration-approved EGFR inhibitor for this malignancy, significantly enhanced growth inhibition. Finally, HNSCC cells rendered resistant to erlotinib retained sensitivity to the growth inhibitory effects of honokiol.
-   These results suggest that honokiol may be an effective therapeutic agent in HNSCC, in which it can augment the effects of EGFR inhibitors and overcome drug resistance.
Mesh:Animals,Antibodies, Monoclonal,Antibodies, Monoclonal, Humanized,Antineoplastic Agents, Phytogenic,Antineoplastic Combined Chemotherapy Protocols,Apoptosis,Biphenyl Compounds,Blotting, Western,Carcinoma, Squamous Cell,Cell Line, Tumor,Cell Proliferation,Cell Survival,Cetuximab,Dose-Response Relationship, Drug,Drug Synergism,Drugs, Chinese Herbal,Erlotinib Hydrochloride,Head and Neck Neoplasms,Humans,Lignans,Mice,Mice, Nude,Quinazolines,Receptor, Epidermal Growth Factor,Signal Transduction,Xenograft Model Antitumor Assays

Honokiol induces paraptosis and apoptosis and exhibits schedule-dependent synergy in combination with imatinib in human leukemia cells. [20374036]
Honokiol, an active component isolated and purified from Chinese traditional herb magnolia, has been shown to inhibit growth and induce apoptosis in different cancer cell lines. This study shows that honokiol can induce a cell death distinct from apoptosis at lower concentrations. The death was characterized by cytoplasmic vacuolization with the endoplasmic reticulum swelling and accompanied by apoptosis at higher concentrations in NB4 and K562 cells. The two death processes may be in sequence at lower concentrations and in parallel with the increase of honokiol concentration. Membrane-associated cytotoxicity was involved in honokiol-induced paraptosis and apoptosis. Furthermore, honokiol inhibited concentration-dependent cell adhesion to extracellular matrix for NB4 cells. In addition, the cytotoxicity of honokiol combined treatment with imatinib was schedule- and concentration-dependent and the sequential administration of honokiol before imatinib appeared to be more beneficial in K562 cells. Taken together, the data suggest that honokiol induced a novel cell death pathway and there was cross-talk between apoptotic and non-apoptotic programmed cell death caused by honokiol in leukemia cells. Moreover, honikiol exhibited schedule-dependent synergy in combination with imatinib and sequential administration of imatinib followed by honokiol could be the optimal sequence to combine these two drugs in K562 cells.
Mesh:Antineoplastic Combined Chemotherapy Protocols,Apoptosis,Benzamides,Biphenyl Compounds,Cell Line, Tumor,Cell Membrane,Cell Proliferation,Drug Administration Schedule,Drug Synergism,Humans,Imatinib Mesylate,Leukemia,Lignans,Piperazines,Pyrimidines,Vacuoles

Anti-inflammatory bioactivities of honokiol through inhibition of protein kinase C, mitogen-activated protein kinase, and the NF-kappaB pathway to reduce LPS-induced TNFalpha and NO expression. [20192217]
Much recent research has demonstrated that honokiol, a phenolic compound originally isolated from Magnolia officinalis, has potent anticancer activities; however, the detailed molecular mechanism of its anti-inflammatory activity has not yet been fully addressed. In this study we demonstrated that honokiol inhibited lipopolysaccharide (LPS)-induced tumor necrosis factor-alpha secretion in macrophages, without affecting the activity of the tumor necrosis factor-alpha converting enzyme. At the same time, honokiol not only inhibited nitric oxide expression in LPS-stimulated murine macrophages but also inhibited the LPS-induced phosphorylation of ERK1/2, JNK1/2, and p38. By means of confocal microscope analysis we demonstrated that phosphorylation and membrane translocation of protein kinase C-alpha, as well as NF-kappaB activation, were inhibited by honokiol in LPS-stimulated macrophages. Furthermore, it was found that honokiol neither antagonizes the binding of LPS to cells nor alters the cell surface expression of toll-like receptor 4 and CD14. Our current results have exhaustively described the anti-inflammatory properties of honokiol, which could lead to the possibility of its future pharmaceutical application in the realm of immunomodulation.
Mesh:Animals,Anti-Inflammatory Agents,Biphenyl Compounds,Cell Line,Cells, Cultured,Down-Regulation,Humans,Lignans,Lipopolysaccharides,Macrophages,Mice,Mitogen-Activated Protein Kinases,NF-kappa B,Nitric Oxide,Protein Kinase C,Signal Transduction,Tumor Necrosis Factor-alpha

Honokiol inhibits HepG2 migration via down-regulation of IQGAP1 expression discovered by a quantitative pharmaceutical proteomic analysis. [20127691]
Honokiol (HNK), a natural small molecular product, inhibited proliferation of HepG2 cells and exhibited anti-tumor activity in nude mice. In this article, we applied a novel sensitive stable isotope labeling with amino acids in cell culture-based quantitative proteomic method and a model of nude mice to investigate the correlation between HNK and the hotspot migration molecule Ras GTPase-activating-like protein (IQGAP1). The quantitative proteomic analysis showed that IQGAP1 was 0.53-fold down-regulated under 10 microg/mL HNK exposure for 24 h on HepG2 cells. Migration ability of HepG2 cells under HNK treatment was correlated with its expression level of IQGAP1. In addition, the biochemical validation on HepG2 cells and the tumor xenograft model further demonstrated that HNK decreased the expression level of IQGAP1 and its upstream proteins Cdc42/Rac1. These data supported that HNK can modulate cell adhesion and cell migration by acting on Cdc42/Rac1 signaling via IQGAP1 interactions with its upstream Cdc42/Rac1 proteins, which is a new molecular mechanism of HNK to exert its anti-tumor activity.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Cell Movement,Down-Regulation,Hep G2 Cells,Histocytochemistry,Humans,Isotope Labeling,Lignans,Mice,Mice, Nude,Proteome,Proteomics,Reproducibility of Results,Statistics, Nonparametric,Tumor Burden,cdc42 GTP-Binding Protein,rac1 GTP-Binding Protein,ras GTPase-Activating Proteins

Honokiol induces cell apoptosis in human chondrosarcoma cells through mitochondrial dysfunction and endoplasmic reticulum stress. [19880244]
Chondrosarcoma is a malignant primary bone tumor that responds poorly to both chemotherapy and radiation therapy. In the present study, we investigated the anti-cancer effect of a honokiol, an active component isolated and purified from the Magnolia officinalis in human chondrosarcoma cells. Honokiol-induced cell apoptosis in human chondrosarcoma cell lines (including: JJ012 and SW1353) but not primary chondrocytes. Honokiol also induces upregulation of Bax and Bak, downregulation of Bcl-XL and dysfunction of mitochondria in chondrosarcoma cells. Honokiol triggered endoplasmic reticulum (ER) stress, as indicated by changes in cytosol-calcium levels. We also found that honokiol increased the expression and activities of glucose-regulated protein 78 (GRP78) and calpain. Transfection of cells with GRP78 or calpain siRNA reduced honokiol-mediated cell apoptosis in JJ012 cells. Importantly, animal studies have revealed a dramatic 53% reduction in tumor volume after 21days of treatment. This study demonstrates that honokiol may be a novel anti-cancer agent targeting chondrosarcoma cells.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Bone Neoplasms,Calcium,Calpain,Cell Line, Tumor,Chondrosarcoma,Endoplasmic Reticulum,Heat-Shock Proteins,Humans,Lignans,Male,Mice,Mice, Inbred BALB C,Mitochondria,Xenograft Model Antitumor Assays

Improved therapeutic efficacy against murine carcinoma by combining honokiol with gene therapy of PNAS-4, a novel pro-apoptotic gene. [19575751]
PNAS-4, a novel pro-apoptotic gene activated during the early response to DNA damage, can inhibit proliferation via apoptosis when overexpressed in some tumor cells. Recent studies have indicated that honokiol can induce apoptosis, inhibit angiogenesis, and suppress tumor growth. In the present study, we investigated whether mouse PNAS-4 (mPNAS-4) could augment the apoptosis of tumor cells induced by honokiol in vitro, and whether the antiangiogenic activity of honokiol and induction of apoptosis by mPNAS-4 could work cooperatively to improve the antitumor efficacy in vivo. In vitro, mPNAS-4 inhibited proliferation of murine colorectal carcinoma CT26 and Lewis lung carcinoma LL2 cells through induction of apoptosis, and significantly augmented the apoptosis of CT26 and LL2 cells induced by honokiol. Compared with treatment with mPNAS-4 or honokiol alone, in vivo systemic administration of an expression plasmid encoding mPNAS-4 and low-dose honokiol significantly suppressed tumor growth through the enhanced induction of apoptosis and the augmented inhibition of angiogenesis. Our data suggest that the combined treatment with mPNAS-4 plus honokiol augments antitumor effects in vitro and in vivo, and that the improved antitumor activity in vivo may be associated with enhanced induction of apoptosis and augmented inhibition of angiogenesis. The present study may provide a novel and effective method for the treatment of cancer.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Apoptosis,Apoptosis Regulatory Proteins,Biphenyl Compounds,Carcinoma, Lewis Lung,Cell Proliferation,Colonic Neoplasms,Combined Modality Therapy,Female,Genetic Therapy,Humans,In Situ Nick-End Labeling,Lignans,Liposomes,Mice,Mice, Inbred BALB C,Mice, Inbred C57BL,Nitric Oxide Synthase,Tumor Cells, Cultured

Honokiol-mediated inhibition of PI3K/mTOR pathway: a potential strategy to overcome immunoresistance in glioma, breast, and prostate carcinoma without impacting T cell function. [19483651]
Inhibition of the phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) pathway is an appealing method for decreasing the immunoresistance and augmenting T cell-mediated immunotherapy. A major impediment to this strategy is the impact of conventional PI3K/mTOR pathway inhibitors on T cell function. In particular, rapamycin, is a well-known immunosuppressant that can decrease the activity of the PI3K/mTOR pathway in tumor cells, but also has a profound inhibitory effect on T cells. Here we show that Honokiol, a natural dietary product isolated from an extract of seed cones from Magnolia grandiflora, can decrease PI3K/mTOR pathway-mediated immunoresistance of glioma, breast and prostate cancer cell lines, without affecting critical proinflammatory T cell functions. Specifically, we show that at doses sufficient to down-regulate levels of phospho-S6 and the negative immune regulator B7-H1 in tumor cells, Honokiol does not significantly impair T cell proliferation or proinflammatory cytokine production. In contrast to classic inhibitors, including LY294002, wortmannin, AKT inhibitor III and rapamycin, Honokiol specifically decreases the PI3K/mTOR pathway activity in tumor cells, but not in freshly stimulated T cells. Collectively, our data define a unique application for Honokiol and provide the impetus to more fully elucidate the mechanism by which T cells are resistant to the effects of this particular inhibitor. Honokiol is clinically available for human testing and may serve to augment T cell-mediated cancer immunotherapy.
Mesh:Androstadienes,Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Breast Neoplasms,Carcinoma,Cell Line, Tumor,Chromones,Coculture Techniques,Enzyme Inhibitors,Female,Glioma,Humans,Immune Tolerance,Interferon-gamma,Interleukin-17,Lignans,Male,Morpholines,Phosphatidylinositol 3-Kinases,Prostatic Neoplasms,Protein Kinase Inhibitors,Protein Kinases,T-Lymphocytes,TOR Serine-Threonine Kinases

Liposomal honokiol inhibits VEGF-D-induced lymphangiogenesis and metastasis in xenograft tumor model. [19219913]
Lymph nodes metastasis of tumor could be a crucial early step in the metastatic process. Induction of tumor lymphangiogenesis by vascular endothelial growth factor-D may play an important role in promoting tumor metastasis to regional lymph nodes and these processes can be inhibited by inactivation of the VEGFR-3 signaling pathway. Honokiol has been reported to possess potent antiangiogenesis and antitumor properties in several cell lines and xenograft tumor models. However, its role in tumor-associated lymphangiogenesis and lymphatic metastasis remains unclear. Here, we established lymph node metastasis models by injecting overexpressing VEGF-D Lewis lung carcinoma cells into C57BL/6 mice to explore the effect of honokiol on tumor-associated lymphangiogenesis and related lymph node metastasis. The underlying mechanisms were systematically investigated in vitro and in vivo. In in vivo study, liposomal honokiol significantly inhibited the tumor-associated lymphangiogenesis and metastasis in Lewis lung carcinoma model. A remarkable delay of tumor growth and prolonged life span were also observed. In in vitro study, honokiol inhibited VEGF-D-induced survival, proliferation and tube-formation of both human umbilical vein endothelial cells (HUVECs) and lymphatic vascular endothelial cells (HLECs). Western blotting analysis showed that liposomal honokiol-inhibited Akt and MAPK phosphorylation in 2 endothelial cells, and downregulated expressions of VEGFR-2 of human vascular endothelial cells and VEGFR-3 of lymphatic endothelial cells. Thus, we identified for the first time that honokiol provided therapeutic benefit not only by direct effects on tumor cells and antiangiogenesis but also by inhibiting lymphangiogenesis and metastasis via the VEGFR-3 pathway. The present findings may be of importance to investigate the molecular mechanisms underlying the spread of cancer via the lymphatics and explore the therapeutical strategy of honokiol on antilymphangiogenesis and antimetastasis.
Mesh:Angiogenesis Inhibitors,Animals,Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Carcinoma, Lewis Lung,Cell Line,Endothelial Cells,Female,Humans,Lignans,Liposomes,Lymphangiogenesis,Lymphatic Metastasis,Mice,Mice, Inbred C57BL,Vascular Endothelial Growth Factor D,Vascular Endothelial Growth Factor Receptor-3,Xenograft Model Antitumor Assays

Different redox states in malignant and nonmalignant esophageal epithelial cells and differential cytotoxic responses to bile acid and honokiol. [19187006]
Esophageal adenocarcinoma (EAC) is a highly lethal cancer in western countries. EAC cells are believed to develop from esophageal epithelial cells through complex transformation processes involving inflammation and oxidative stress. The purpose of this study was to compare the redox status of malignant and nonmalignant esophageal epithelial cells and to test their responses to bile acid-induced oxidative stress and to treatment with honokiol (HNK), a natural product with anticancer activity. We demonstrated that esophageal adenocarcinoma cells express significantly higher levels of antioxidant molecules and were resistant to reactive oxygen species (ROS) stress induced by bile acid, but were sensitive to the cytotoxic action of HNK. Mechanistic study showed that HNK caused cancer cell death by disruption of mitochondrial transmembrane potential and was correlated with cyclophilin D (CypD) expression. Inhibition of CypD by cyclosporin A or abrogation of its expression by siRNA significantly suppressed the cytotoxicity of HNK, suggesting that CypD may be a key molecule that mediates the cytotoxicity. Our study suggests that the high antioxidant capacity in EAC cells confers on them the ability to survive the oxidative microenvironment in the reflux esophagus, and that HNK is a promising compound to kill the transformed cells preferentially.
Mesh:Adenocarcinoma,Base Sequence,Bile Acids and Salts,Biphenyl Compounds,Cell Line, Transformed,Cyclophilins,Epithelial Cells,Esophageal Neoplasms,Esophagus,Humans,Lignans,Oxidation-Reduction,RNA, Small Interfering

Down-regulation of c-Src/EGFR-mediated signaling activation is involved in the honokiol-induced cell cycle arrest and apoptosis in MDA-MB-231 human breast cancer cells. [19135778]
Honokiol is a naturally occurring neolignan abundant in Magnoliae Cortex and has showed anti-proliferative and pro-apoptotic effects in a wide range of human cancer cells. However, the molecular mechanisms on the anti-proliferative activity in cancer cells have been poorly elucidated. In this study, we evaluated the growth inhibitory activity of honokiol in cultured estrogen receptor (ER)-negative MDA-MB-231 human breast cancer cells. Honokiol exerted anti-proliferative activity with the cell cycle arrest at the G0/G1 phase and sequential induction of apoptotic cell death in a concentration-dependent manner. The honokiol-induced cell cycle arrest was well correlated with the suppressive expression of CDK4, cyclin D1, CDK2, cyclin E, c-Myc, and phosphorylated retinoblastoma protein (pRb) at Ser780. Apoptosis caused by honokiol was also concomitant with the cleavage of caspases (caspase-3, -8, and -9) and Bid along with the suppressive expression of Bcl-2, but it was independent on the expression of Bax and p53. In addition, honokiol-treated cells exhibited the cleavage of poly (ADP-ribose) polymerase (PARP) and DNA fragmentation. In the analysis of signal transduction pathway, honokiol down-regulated the expression and phosphorylation of c-Src, epidermal growth factor receptor (EGFR), and Akt, and consequently led to the inactivation of mTOR and its downstream signal molecules including 4E-binding protein (4E-BP) and p70 S6 kinase. These findings suggest that honokiol-mediated inhibitory activity of cancer cell growth might be related with the cell cycle arrest and induction of apoptosis via modulating signal transduction pathways.
Mesh:Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Breast Neoplasms,Cell Cycle,Cell Cycle Proteins,Cell Line, Tumor,Down-Regulation,Female,Humans,Lignans,Phosphorylation,Protein-Tyrosine Kinases,Receptor, Epidermal Growth Factor,Signal Transduction,Tumor Suppressor Proteins,src-Family Kinases

Liposomal honokiol, a potent anti-angiogenesis agent, in combination with radiotherapy produces a synergistic antitumor efficacy without increasing toxicity. [19116447]
Honokiol is an active compound purified from magnolia that has been shown to induce cell differentiation, apoptosis, and anti-angiogenesis effects, as well as an enhancement in tumor growth delay in combination with chemotherapeutic agents in several mouse xenograft models. Our goal was to investigate the radiosensitization effect of honokiol on lung carcinoma. The radiosensitization effect of liposomal honokiol in Lewis lung carcinoma cells (LL/2) was analyzed using an in vitro clonogenic survival assay. For an in vivo study, Lewis lung carcinoma-bearing C57BL/6 mice were treated with either liposomal honokiol at 25 mg/kg or 5 Gy of single tumor radiation, or a combination of both over 12 days of treatment. The tumor growth delay and the survival time were evaluated. In addition, histological analysis of tumor sections was performed to examine changes by detecting the microvessel density and apoptosis in tumor tissues. In the clonogenic survival assay, LL/2 cells treated with IC(50) Lipo-HNK for 24 h showed a radiation enhancement ratio of 1.9. After 12 days of combination treatment, the tumor volume decreased 78% and produced an anti-tumor activity 1.3-fold greater than a predicted additive effect of honokiol and radiation alone. This combination treatment also caused an 8.7 day delay in tumor growth. The cell cycle distribution and histological analysis demonstrated that liposomal honokiol has an anti-tumor effect via inducing apoptosis and inhibiting angiogenesis. Liposomal honokiol can enhance tumor cell radiosensitivity in vitro and in vivo, indicating that radiotherapy combined with liposomal honokiol can lead to greater anti-tumor efficacy.
Mesh:Angiogenesis Inhibitors,Animals,Apoptosis,Biphenyl Compounds,Carcinoma, Lewis Lung,Cell Cycle,Cell Line, Tumor,Combined Modality Therapy,Humans,Lignans,Liposomes,Lung Neoplasms,Magnolia,Mice,Neoplasm Transplantation,Neovascularization, Pathologic,Radiation Tolerance,Transplantation, Heterologous

[Effects of honokiol on proliferation and apoptosis of human cervical carcinoma cell line Hela in vitro]. [18798493]
To assess the effects of honokiol on proliferation and apoptosis of human cervical carcinoma cell line Hela in vitro.
-   Cultured HeLa cells were treated with different concentrations of honokiol for the varieties of period (24, 48, 72, 96 h). Cell proliferation was assessed by MTT colorimetric assay. Cell apoptosis was determined by flow cytometry (FCM), Hoechst 33258 fluorescent staining and DNA ladder respectively.
-   MTT assay demonstrated that the proliferation of Hela cells were suppressed significantly by honokiol in dose-and time-dependent manner. FCM analysis showed that the apoptosis rates of Hela cells treated with 10 microg/mL and 20 microg/mL honokiol for 24 h were 22.5% and 62.2%, respectively, while that of the control group cells was 8.7%. After treatment with honokiol, typically morphologic changes of apoptosis were observed by Hoechst 33258 fluorescence staining; Genomic DNA from Hela cells treated with honokiol displayed a characteristic ladder pattern on agarose gel electrophoresis.
-   honokiol can inhibit the proliferation and induce apoptosis of human cervical carcinoma cell line Hela.
Mesh:Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Cell Proliferation,Cell Survival,Dose-Response Relationship, Drug,Drugs, Chinese Herbal,Flow Cytometry,HeLa Cells,Humans,Lignans,Time Factors

Improved therapeutic effectiveness by combining liposomal honokiol with cisplatin in lung cancer model. [18706101]
Honokiol is a major bioactive compound extracted from Magnolia. The present study was designed to determine whether liposomal honokiol has the antitumor activity against human lung cancer as well as potentiates the antitumor activity of cisplatin in A549 lung cancer xenograft model, if so, to examine the possible mechanism in the phenomenon.
-   human A549 lung cancer-bearing nude mice were treated with liposomal honokiol, liposomal honokiol plus DDP or with control groups. Apoptotic cells and vessels were evaluated by fluorescent in situ TUNEL assay and by immunohistochemistry with an antibody reactive to CD31 respectively.
-   The present study showed that liposomal honokiol alone resulted in effective suppression of the tumor growth, and that the combined treatment with honokiol plus DDP had the enhanced inhibition of the tumor growth and resulted in a significant increase in life span. The more apparent apoptotic cells in the tumors treated with honokiol plus DDP was found in fluorescent in situ TUNEL assay, compared with the treatment with control groups. In addition, the combination of honokiol and DDP apparently reduced the number of vessels by immunolabeling of CD31 in the tissue sections, compared with control groups.
-   In summary, our data suggest that honokiol alone had the antitumor activity against human lung cancer in A549 lung cancer xenograft model, and that the combination of honokiol with DDP can enhance the antitumor activity, and that the enhanced antitumor efficacy in vivo may in part result from the increased induction of the apoptosis and the enhanced inhibition of angiogenesis in the combined treatment. The present findings may be of importance to the further exploration of the potential application of the honokiol alone or the combined approach in the treatment of lung carcinoma.
Mesh:Animals,Antineoplastic Combined Chemotherapy Protocols,Apoptosis,Biphenyl Compounds,Cell Line, Tumor,Cisplatin,Humans,In Situ Nick-End Labeling,Lignans,Liposomes,Lung Neoplasms,Mice,Neoplasm Transplantation,Neovascularization, Pathologic,Plant Extracts,Platelet Endothelial Cell Adhesion Molecule-1

The natural product honokiol preferentially inhibits cellular FLICE-inhibitory protein and augments death receptor-induced apoptosis. [18645030]
Targeting death receptor-mediated apoptosis has emerged as an effective strategy for cancer therapy. However, certain types of cancer cells are intrinsically resistant to death receptor-mediated apoptosis. In an effort to identify agents that can sensitize cancer cells to death receptor-induced apoptosis, we have identified honokiol, a natural product with anticancer activity, as shown in various preclinical studies, as an effective sensitizer of death receptor-mediated apoptosis. Honokiol alone moderately inhibited the growth of human lung cancer cells; however, when combined with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), greater effects on decreasing cell survival and inducing apoptosis than TRAIL alone were observed, indicating that honokiol cooperates with TRAIL to enhance apoptosis. This was also true to Fas-induced apoptosis when combined with Fas ligand or an agonistic anti-Fas antibody. Among several apoptosis-associated proteins tested, cellular FLICE-inhibitory protein (c-FLIP) was the only one that was rapidly down-regulated by honokiol in all of the tested cell lines. The down-regulation of c-FLIP by honokiol could be prevented by the proteasome inhibitor MG132. Moreover, honokiol increased c-FLIP ubiquitination. These results indicate that honokiol down-regulates c-FLIP by facilitating its degradation through a ubiquitin/proteasome-mediated mechanism. Enforced expression of ectopic c-FLIP abolished the ability of honokiol to enhance TRAIL-induced apoptosis. Several honokiol derivatives, which exhibited more potent effects on down-regulation of c-FLIP than honokiol, showed better efficacy than honokiol in inhibiting the growth and enhancing TRAIL-induced apoptosis as well. Collectively, we conclude that c-FLIP down-regulation is a key event for honokiol to modulate the death receptor-induced apoptosis.
Mesh:Apoptosis,Biphenyl Compounds,CASP8 and FADD-Like Apoptosis Regulating Protein,Carcinoma, Non-Small-Cell Lung,Cell Line, Tumor,Cell Proliferation,Cell Survival,Down-Regulation,Humans,JNK Mitogen-Activated Protein Kinases,Lignans,Lung Neoplasms,Proteasome Endopeptidase Complex,Protein Processing, Post-Translational,Receptors, Death Domain,TNF-Related Apoptosis-Inducing Ligand,Ubiquitin

Honokiol suppresses survival signals mediated by Ras-dependent phospholipase D activity in human cancer cells. [18594009]
Elevated phospholipase D (PLD) activity provides a survival signal in several human cancer cell lines and suppresses apoptosis when cells are subjected to the stress of serum withdrawal. Thus, targeting PLD survival signals has potential to suppress survival in cancer cells that depend on PLD for survival. Honokiol is a compound that suppresses tumor growth in mouse models. The purpose of this study was to investigate the effect of honokiol on PLD survival signals and the Ras dependence of these signals.
-   The effect of honokiol upon PLD activity was examined in human cancer cell lines where PLD activity provides a survival signal. The dependence of PLD survival signals on Ras was investigated, as was the effect of honokiol on Ras activation.
-   We report here that honokiol suppresses PLD activity in human cancer cells where PLD has been shown to suppress apoptosis. PLD activity is commonly elevated in response to the stress of serum withdrawal, and, importantly, the stress-induced increase in PLD activity is selectively suppressed by honokiol. The stress-induced increase in PLD activity was accompanied by increased Ras activation, and the stress-induced increase in PLD activity in MDA-MB-231 breast cancer cells was dependent on a Ras. The PLD activity was also dependent on the GTPases RalA and ADP ribosylation factor. Importantly, honokiol suppressed Ras activation.
-   The data provided here indicate that honokiol may be a valuable therapeutic reagent for targeting a large number of human cancers that depend on Ras and PLD for their survival.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Cell Line, Tumor,Cell Survival,Enzyme Activation,Humans,Lignans,Mice,Models, Chemical,Neoplasm Transplantation,Neoplasms,Phospholipase D,Signal Transduction,ras Proteins

Anti-tumor effect of honokiol alone and in combination with other anti-cancer agents in breast cancer. [18588872]
Honokiol, an active component isolated and purified from Chinese traditional herb magnolia, was demonstrated to inhibit growth and induce apoptosis of different cancer cell lines such as human leukaemia, colon, and lung cancer cell lines; to attenuate the angiogenic activities of human endothelial cells in vitro; and to efficiently suppress the growth of angiosarcoma in nude mice. In this study, we have demonstrated that treatment of different human breast cancer cell lines with honokiol resulted in a time- and concentration-dependent growth inhibition in both estrogen receptor-positive and -negative breast cancer cell lines, as well as in drug-resistant breast cancer cell lines such as adriamycin-resistant and tamoxifen-resistant cell lines. The inhibition of growth was associated with a G1-phase cell cycle arrest and induction of caspase-dependent apoptosis. The effects of honokiol might be reversely related to the expression level of human epidermal growth receptor 2, (HER-2, also known as erbB2, c-erbB2) since knockdown of her-2 expression by siRNA significantly enhanced the sensitivity of the her-2 over-expressed BT-474 cells to the honokiol-induced apoptosis. Furthermore, inhibition of HER-2 signalling by specific human epidermal growth receptor 1/HER-2 (EGFR/HER-2) kinase inhibitor lapatinib synergistically enhanced the anti-cancer effects of honokiol in her-2 over-expressed breast cancer cells. Finally, we showed that honokiol was able to attenuate the PI3K/Akt/mTOR (Phosphoinositide 3-kinases/Akt/mammalian target of rapamycin) signalling by down-regulation of Akt phosphorylation and upregulation of PTEN (Phosphatase and Tensin homolog deleted on chromosome Ten) expression. Combination of honokiol with the mTOR inhibitor rapamycin presented synergistic effects on induction of apoptosis of breast cancer cells. In conclusion, honokiol, either alone or in combination with other therapeutics, could serve as a new, promising approach for breast cancer treatment.
Mesh:Animals,Antineoplastic Combined Chemotherapy Protocols,Apoptosis,Biphenyl Compounds,Breast Neoplasms,Cell Line, Tumor,Dose-Response Relationship, Drug,Drug Resistance, Neoplasm,Drug Screening Assays, Antitumor,Drug Synergism,Female,Gene Expression Regulation, Neoplastic,Humans,Lignans,Magnolia,Medicine, Chinese Traditional,Quinazolines,Signal Transduction,Sirolimus,Time Factors

Involvement of p38 mitogen-activated protein kinase pathway in honokiol-induced apoptosis in a human hepatoma cell line (hepG2). [18507762]
Honokiol has been known to have antitumour activity. This study was conducted to evaluate the antiproliferative potential of honokiol against the hepG2 heptocellular cell line and its mechanism of action.
-   hepG2 cells were treated with honokiol of 0-40 microg/ml concentration. The cytotoxic effect of honokiol was determined by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The apoptosis was evaluated by flow cytometry. Western blots were used to analyse the expression of various proteins (procaspase-9, procaspase-3, cleaved caspase-3, cytochrome c, Bcl-2, Bax, Bad, Bcl-X(L) and p38).
-   Honokiol induced apoptosis with a decreased expression of procaspase-3 and -9 and an increased expression of active caspase-3. Exposure of hepG2 cells to honokiol resulted in the downregulation of Bcl-X(L) and Bcl-2 expression and the release of mitochondrial cytochrome c to the cytosol. In addition, honokiol activated the p38 mitogen-activated protein kinase (MAPK) pathway, and the inhibition of this pathway by SB203580 reduced honokiol-induced apoptosis and activation of caspase-3.
-   Honokiol induces apoptosis of hepG2 human hepatocellular carcinoma cells through activation of the p38 MAPK pathway, and, in turn, activation of caspase-3.
Mesh:Apoptosis,Biphenyl Compounds,Blotting, Western,Carcinoma, Hepatocellular,Caspases,Cell Line, Tumor,Cell Proliferation,Flow Cytometry,Humans,Imidazoles,Lignans,Pyridines,Signal Transduction,Tetrazolium Salts,Thiazoles,p38 Mitogen-Activated Protein Kinases

Honokiol, a natural therapeutic candidate, induces apoptosis and inhibits angiogenesis of ovarian tumor cells. [18440692]
To observe the anti-tumor activities of honokiol on human ovarian tumor in vitro and in vivo.
-   Cells were treated with honokiol, and the effects on proliferation and apoptosis were examined by MTT, DNA ladder, Hoechst staining, and flow cytometry assays. Expression of Bcl-2 members and caspase-3 were assessed. Measurements of tumor volume and microvessel densities (MVDs) were performed.
-   Honokiol significantly inhibited proliferation and induced apoptosis, with alteration of Bcl-2 members and caspase-3. Administration of honokiol to tumor-bearing animals decreased MVD and resulted in inhibition of tumor growth.
-   Honokiol could induce apoptosis and inhibit angiogenesis in vitro and in vivo, suggesting a novel and attractive therapeutic candidate for ovarian tumor treatment.
Mesh:Angiogenesis Inhibitors,Animals,Apoptosis,Biphenyl Compounds,Cell Line, Tumor,Disease Models, Animal,Female,Humans,Lignans,Mice,Mice, Nude,Neovascularization, Pathologic,Ovarian Neoplasms

Inhibition of NADPH oxidase-related oxidative stress-triggered signaling by honokiol suppresses high glucose-induced human endothelial cell apoptosis. [18423412]
Angiopathy is a major complication of diabetes. Abnormally high blood glucose is a crucial risk factor for endothelial cell damage. Nuclear factor-kappaB (NF-kappaB) has been demonstrated as a mediated signaling in hyperglycemia or oxidative stress-triggered apoptosis of endothelial cells. Here we explored the efficacy of honokiol, a small molecular weight natural product, on NADPH oxidase-related oxidative stress-mediated NF-kappaB-regulated signaling and apoptosis in human umbilical vein endothelial cells (HUVECs) under hyperglycemic conditions. The methods of morphological Hoechst staining and annexin V/propidium iodide staining were used to detect apoptosis. Submicromolar concentrations of honokiol suppressed the increases of NADPH oxidase activity, Rac-1 phosphorylation, p22(phox) protein expression, and reactive oxygen species production in high glucose (HG)-stimulated HUVECs. The degradation of IkappaBalpha and increase of NF-kappaB activity were inhibited by honokiol in HG-treated HUVECs. Moreover, honokiol (0.125-1 microM) also suppressed HG-induced cyclooxygenase (COX)-2 upregulation and prostaglandin E(2) production in HUVECs. Honokiol could reduce increased caspase-3 activity and the subsequent apoptosis and cell death triggered by HG. These results imply that inhibition of NADPH oxidase-related oxidative stress by honokiol suppresses the HG-induced NF-kappaB-regulated COX-2 upregulation, apoptosis, and cell death in HUVECs, which has the potential to be developed as a therapeutic agent to prevent hyperglycemia-induced endothelial damage.
Mesh:Apoptosis,Biphenyl Compounds,Cyclooxygenase 2,Endothelial Cells,Endothelium, Vascular,Enzyme Activation,Glucose,Humans,Lignans,NADPH Oxidases,NF-kappa B,Oxidative Stress,Phosphorylation,Reactive Oxygen Species,Signal Transduction,Umbilical Veins,rac1 GTP-Binding Protein

Liposomal honokiol, a promising agent for treatment of cisplatin-resistant human ovarian cancer. [18350317]
Honokiol has been receiving attention as an anticancer agent because of its anti-tumor effect. In the current study, we encapsulated honokiol with liposome and tested it on cisplatin-sensitive (A2780s) and -resistant (A2780cp) human ovarian cancer models.
-   The anti-tumor activity of liposomal honokiol (Lipo-HNK) was evaluated in nude mice bearing A2780s and A2780cp s.c. tumors. Mice were treated twice weekly with i.v. administration of Lipo-HNK (10 mg/kg), control liposome (10 mg/kg), 0.9% NaCl solution or weekly with intraperitoneally administered cisplatin (5 mg/kg) for 3 weeks. Tumor volume and survival time were observed. Assessment of apoptotic cells by TUNEL assay was conducted in tumor tissue. Microvessel density within tumor tissue was determined by CD34 immunohistochemistry. For in vitro study, induction of apoptosis by Lipo-HNK was examined by PI staining fluorescence microscopy, DNA fragmentation assay and flow cytometric analysis.
-   Administration of Lipo-HNK resulted in significant inhibition (84-88% maximum inhibition relative to controls) in the growth of A2780s and A2780cp tumor xenografts and prolonged the survival of the treated mice. These anti-tumor responses were associated with marked increases in tumor apoptosis, and reductions in intratumoral microvessel density.
-   The present findings suggest that Lipo-HNK may provide an effective approach to inhibit tumor growth in both cisplatin sensitive and -resistant human ovarian cancer with minimal side effects.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Cell Line, Tumor,Cisplatin,Drug Resistance, Neoplasm,Female,Humans,Immunohistochemistry,Lignans,Liposomes,Mice,Mice, Nude,Ovarian Neoplasms

Honokiol, a constituent of oriental medicinal herb magnolia officinalis, inhibits growth of PC-3 xenografts in vivo in association with apoptosis induction. [18281560]
This study was undertaken to determine the efficacy of honokiol, a constituent of oriental medicinal herb Magnolia officinalis, against human prostate cancer cells in culture and in vivo.
-   Honokiol-mediated apoptosis was assessed by analysis of cytoplasmic histone-associated DNA fragmentation. Knockdown of Bax and Bak proteins was achieved by transient transfection using siRNA. Honokiol was administered by oral gavage to male nude mice s.c. implanted with PC-3 cells. Tumor sections from control and honokiol-treated mice were examined for apoptotic bodies (terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling assay), proliferation index (proliferating cell nuclear antigen staining), and neovascularization (CD31 staining). Levels of Bcl-2 family proteins in cell lysates and tumor supernatants were determined by immunoblotting.
-   Exposure of human prostate cancer cells (PC-3, LNCaP, and C4-2) to honokiol resulted in apoptotic DNA fragmentation in a concentration- and time-dependent manner irrespective of their androgen responsiveness or p53 status. Honokiol-induced apoptosis correlated with induction of Bax, Bak, and Bad and a decrease in Bcl-xL and Mcl-1 protein levels. Transient transfection of PC-3 cells with Bak- and Bax-targeted siRNAs and Bcl-xL plasmid conferred partial yet significant protection against honokiol-induced apoptosis. Oral gavage of 2 mg honokiol/mouse (thrice a week) significantly retarded growth of PC-3 xenografts without causing weight loss. Tumors from honokiol-treated mice exhibited markedly higher count of apoptotic bodies and reduced proliferation index and neovascularization compared with control tumors.
-   Our data suggest that honokiol, which is used in traditional oriental medicine for the treatment of various ailments, may be an attractive agent for treatment and/or prevention of human prostate cancers.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Cell Line, Tumor,Humans,Immunoblotting,Lignans,Magnolia,Male,Mice,Mice, Nude,Myeloid Cell Leukemia Sequence 1 Protein,Neoplasm Proteins,Prostatic Neoplasms,Proto-Oncogene Proteins c-bcl-2,bcl-2 Homologous Antagonist-Killer Protein,bcl-2-Associated X Protein,bcl-Associated Death Protein,bcl-X Protein

Anti-inflammatory effect of honokiol is mediated by PI3K/Akt pathway suppression. [18158873]
In this study, we investigated the regulatory effects of honokiol on various inflammatory events mediated by monocytes/macrophages (U937/RAW264.7 cells) and lymphocytes (splenic lymphocytes and CTLL-2 cells) and their putative action mechanism.
-   In order to investigate the regulatory effects, various cell lines and primary cells (U937, RAW264.7, CTLL-2 cells, and splenic lymphocytes) were employed and various inflammatory events, such as the production of inflammatory mediators, cell adhesion, cell proliferation, and the early signaling cascade, were chosen.
-   Honokiol strongly inhibited various inflammatory responses, such as: (i) the upregulation of nitric oxide (NO), prostaglandin E2 and TNF-alpha production and costimulatory molecule CD80 induced by lipopolysaccharide (LPS); (ii) the functional activation of beta1-integrin (CD29) assessed by U937 cell-cell and cell-fibronectin adhesions; (iii) the enhancement of lymphocytes and CD8+CTLL-2 cell proliferation stimulated by LPS, phytohemaglutinin A (PHA), and concanavalin A or interleukin (IL)-2; and (iv) the transcriptional upregulation of inducible NO synthase, TNF-alpha, cyclooxygenase-2, IL-12, and monocyte chemoattractant protein (MCP)-1. These anti-inflammatory effects of honokiol seem to be mediated by interrupting the early activated intracellular signaling molecule phosphoinositide 3-kinase (PI3K)/Akt, but not Src, the extracellular signal-regulated kinase, and p38, according to pharmacological, biochemical, and functional analyses.
-   These results suggest that honokiol may act as a potent anti-inflammatory agent with multipotential activities due to an inhibitory effect on the PI3K/Akt pathway.
Mesh:Anti-Inflammatory Agents,Biphenyl Compounds,Cell Line,Cell Proliferation,Dinoprostone,Fibronectins,Humans,Lignans,Lipopolysaccharides,Lymphocytes,Mitogens,Nitric Oxide,Oncogene Protein v-akt,Phosphatidylinositol 3-Kinases,Signal Transduction,Tetrazolium Salts,Thiazoles,Tumor Necrosis Factor-alpha

Honokiol induces calpain-mediated glucose-regulated protein-94 cleavage and apoptosis in human gastric cancer cells and reduces tumor growth. [17971859]
Honokiol, a small molecular weight natural product, has been shown to possess potent anti-neoplastic and anti-angiogenic properties. Its molecular mechanisms and the ability of anti-gastric cancer remain unknown. It has been shown that the anti-apoptotic function of the glucose-regulated proteins (GRPs) predicts that their induction in neoplastic cells can lead to cancer progression and drug resistance. We explored the effects of honokiol on the regulation of GRPs and apoptosis in human gastric cancer cells and tumor growth.
-   Treatment of various human gastric cancer cells with honokiol led to the induction of GRP94 cleavage, but did not affect GRP78. Silencing of GRP94 by small interfering RNA (siRNA) could induce cell apoptosis. Treatment of cells with honokiol or chemotherapeutics agent etoposide enhanced the increase in apoptosis and GRP94 degradation. The calpain activity and calpain-II (m-calpain) protein (but not calpain-I (micro-calpain)) level could also be increased by honokiol. Honokiol-induced GRP94 down-regulation and apoptosis in gastric cancer cells could be reversed by siRNA targeting calpain-II and calpain inhibitors. Furthermore, the results of immunofluorescence staining and immunoprecipitation revealed a specific interaction of GRP94 with calpain-II in cells following honokiol treatment. We next observed that tumor GRP94 over-expression and tumor growth in BALB/c nude mice, which were inoculated with human gastric cancer cells MKN45, are markedly decreased by honokiol treatment.
-   These results provide the first evidence that honokiol-induced calpain-II-mediated GRP94 cleavage causes human gastric cancer cell apoptosis. We further suggest that honokiol may be a possible therapeutic agent to improve clinical outcome of gastric cancer.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Calpain,Cell Line, Tumor,Glucose,Humans,Kinetics,Lignans,Male,Membrane Glycoproteins,Mice,Mice, Inbred BALB C,Models, Biological,Stomach Neoplasms

Honokiol causes G0-G1 phase cell cycle arrest in human prostate cancer cells in association with suppression of retinoblastoma protein level/phosphorylation and inhibition of E2F1 transcriptional activity. [17938262]
The present study was undertaken to gain insights into the mechanism of cell cycle arrest caused by honokiol, a constituent of oriental herb Magnolia officinalis. The honokiol treatment decreased the viability of PC-3 and LNCaP human prostate cancer cells in a concentration- and time-dependent manner, which correlated with G0-G1 phase cell cycle arrest. The honokiol-mediated cell cycle arrest was associated with a decrease in protein levels of cyclin D1, cyclin-dependent kinase 4 (Cdk4), Cdk6, and/or cyclin E and suppression of complex formation between cyclin D1 and Cdk4 as revealed by immunoprecipitation using anti-cyclin D1 antibody followed by immunoblotting for Cdk4 protein. The honokiol-treated PC-3 and LNCaP cells exhibited a marked decrease in the levels of total and phosphorylated retinoblastoma protein (Rb), which correlated with the suppression of transcriptional activity of E2F1. Exposure of PC-3 and LNCaP cells to honokiol resulted in the induction of p21 (PC-3 and LNCaP) and p53 protein expression (LNCaP). However, small interfering RNA (siRNA)-mediated knockdown of either p21 (PC-3 and LNCaP) or p53 (LNCaP) protein failed to confer any protection against honokiol-induced cell cycle arrest. The honokiol treatment caused the generation of reactive oxygen species (ROS), and the cell cycle arrest caused by honokiol was partially but significantly attenuated in the presence of antioxidant N-acetylcysteine. In conclusion, the present study reveals that the honokiol-mediated G0-G1 phase cell cycle arrest in human prostate cancer cells is associated with the suppression of protein level/phosphorylation of Rb leading to inhibition of transcriptional activity of E2F1.
Mesh:Acetylcysteine,Antineoplastic Agents, Phytogenic,Antioxidants,Biphenyl Compounds,Cell Cycle,Cell Cycle Proteins,Cell Proliferation,Cyclin-Dependent Kinase Inhibitor p21,Drugs, Chinese Herbal,E2F1 Transcription Factor,G1 Phase,Humans,Immunoprecipitation,Lignans,Luciferases,Male,Phosphorylation,Prostatic Neoplasms,RNA, Small Interfering,Reactive Oxygen Species,Resting Phase, Cell Cycle,Retinoblastoma Protein,Transcription, Genetic,Tumor Cells, Cultured,Tumor Suppressor Protein p53

Enhancement of therapeutic effectiveness by combining liposomal honokiol with cisplatin in ovarian carcinoma. [17892458]
Honokiol, a well-tolerated natural product, can inhibit the proliferation of cancer cells. But its water insolubility hampers its systemic administration for therapy of cancer. As a drug delivery system, the pegylated liposome (PEGL) can increase the water solubility and targeting of the drug. Honokiol has been successfully encapsulated by PEGL in our laboratory. We wondered whether the combination treatment with pegylated liposomal honokiol (H-PEGL) and cisplatin (DDP) could improve the antitumor efficacy in ovarian carcinoma. H-PEGL could introduce apoptosis of SKOV3 cells in vitro, which was quantified by flow cytometric analysis, and the cellular morphologic changes were determined by propidium iodide staining. In a human ovarian carcinoma mouse model, combination treatment with H-PEGL (0.4 mg/day for 30 days; intraperitoneal) and DDP (5 mg/kg on days 7, 11, 15, 19; intraperitoneal) acted synergistically to inhibit tumor growth by 91.48% without notable toxicity, but H-PEGL and DDP alone only inhibit tumor growth by 66.83% and 52.5% as compared to the NaCl solution control, respectively. Assessment of microvessel density and apoptosis index by CD31 and terminal deoxynucleotidyl transferase-mediated nick end labeling immunohistochemistry respectively suggested that the antitumor activity of H-PEGL is mediated by angiogenesis inhibition and introduction of apoptosis. Our results showed us a splendid prospect of the clinical application of combination treatment on patients suffering from ovarian cancer with H-PEGL and DDP.
Mesh:Animals,Antineoplastic Combined Chemotherapy Protocols,Apoptosis,Biphenyl Compounds,Carcinoma,Cell Line, Tumor,Cell Proliferation,Cisplatin,Drug Synergism,Female,Humans,Lignans,Liposomes,Mice,Mice, Inbred BALB C,Mice, Nude,Neovascularization, Pathologic,Ovarian Neoplasms,Polyethylene Glycols,Treatment Outcome,Xenograft Model Antitumor Assays

Honokiol, a natural plant product, inhibits inflammatory signals and alleviates inflammatory arthritis. [17617564]
Honokiol (HNK), a phenolic compound isolated and purified from magnolia, has been found to have a number of pharmacologic benefits, including anti-angiogenic and anti-inflammatory properties. HNK has long been used in traditional Asian medicine without toxic side effects. We and others have extensively studied signaling to B cells by CD40 and its Epstein Barr viral mimic, latent membrane protein 1 (LMP1), which has been implicated in exacerbation of chronic autoimmune disease. We asked whether HNK could inhibit CD40 and LMP1 inflammatory signaling mechanisms. In vivo, HNK stabilized the severity of symptomatic collagen-induced arthritis in both CD40-LMP1 transgenic mice and their congenic C57BL/6 counterparts. Ex vivo studies, including collagen-specific serum Ab and Ag recall responses, as well as CD40 or LMP1-mediated activation of splenic B cells, supported the anti-inflammatory effects of HNK. In mouse B cell lines expressing the human CD40-LMP1 chimeric receptor, CD40- and LMP1-mediated NF-kappaB and AP-1 activation were abrogated in a dose-dependent manner, with a concomitant decrease in TNF-alpha and IL-6. These promising findings suggest that the nontoxic anti-inflammatory properties of HNK could be valuable for blocking the autoimmune response.
Mesh:Animals,Anti-Allergic Agents,Arthritis, Experimental,B-Lymphocytes,Biphenyl Compounds,CD40 Antigens,Cell Line,Dose-Response Relationship, Drug,Enzyme-Linked Immunosorbent Assay,Female,Humans,Inflammation,Lignans,Magnolia,Mice,Mice, Transgenic,NF-kappa B,Phytotherapy,Plant Preparations,TNF Receptor-Associated Factor 2,Transcription Factor AP-1

Honokiol induces a necrotic cell death through the mitochondrial permeability transition pore. [17510419]
Previous reports have shown that honokiol induces apoptosis in numerous cancer cell lines and showed preclinical efficacies against apoptosis-resistant B-cell chronic lymphocytic leukemia and multiple myeloma cells from relapse-refractory patients. Here, we show that honokiol can induce a cell death distinct from apoptosis in HL60, MCF-7, and HEK293 cell lines. The death was characterized by a rapid loss of integrity of plasma membrane without externalization of phosphatidyl serine. The broad caspase inhibitor z-VAD-fmk failed to prevent this cell death. Consistently, caspase activation and DNA laddering were not observed. The death was paralleled by a rapid loss of mitochondrial membrane potential, which was mechanistically associated with the mitochondrial permeability transition pore regulated by cyclophilin D (CypD) based on the following evidence: (a) cyclosporin A, an inhibitor of CypD (an essential component of the mitochondrial permeability transition pore), effectively prevented honokiol-induced cell death and loss of mitochondrial membrane potential; (b) inhibition of CypD by RNA interference blocked honokiol-induced cell death; (c) CypD up-regulated by honokiol was correlated with the death rates in HL60, but not in K562 cells, which underwent apoptosis after being exposed to honokiol. We further showed that honokiol induced a CypD-regulated death in primary human acute myelogenous leukemia cells, overcame Bcl-2 and Bcl-X(L)-mediated apoptotic resistance, and was effective against HL60 cells in a pilot in vivo study. To the best of our knowledge, this is the first report to document an induction of mitochondrial permeability transition pore-associated cell death by honokiol.
Mesh:Adult,Aged,Antineoplastic Agents, Phytogenic,Apoptosis Inducing Factor,Biphenyl Compounds,Cell Death,Cell Line, Tumor,Cell Nucleus,Cyclophilins,Female,HL-60 Cells,Humans,Leukemia, Myeloid, Acute,Lignans,Male,Membrane Potential, Mitochondrial,Middle Aged,Mitochondria,Mitochondrial Membrane Transport Proteins,Necrosis,Neoplasms,Reactive Oxygen Species

Honokiol, a natural biphenyl, inhibits in vitro and in vivo growth of breast cancer through induction of apoptosis and cell cycle arrest. [17487375]
Honokiol (HNK), a naturally occurring biphenyl, possesses potent antineoplastic and antiangiogenic properties. We investigated the in vitro and in vivo activity of HNK against breast cancer. HNK exhibited potent anti-proliferative activity against breast cancer cell lines and enhanced the activity of other drugs used for the treatment of breast cancer. In vivo, HNK was highly effective against breast cancer in nude mice. We identified two different effects of HNK on breast cancer cells: cell cycle inhibition, observed at lower doses of HNK, and induction of apoptosis, observed at higher doses of the compound. Our data suggest that HNK is a systemically available, non-toxic inhibitor of breast cancer growth and should be examined for clinical applications.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Antineoplastic Combined Chemotherapy Protocols,Apoptosis,Biphenyl Compounds,Blotting, Western,Breast Neoplasms,Cell Cycle,Cell Proliferation,Doxorubicin,Drug Synergism,Female,Humans,Hydroxamic Acids,In Vitro Techniques,Lignans,Mice,Mice, Nude,Paclitaxel,Tamoxifen

Honokiol, a natural plant product, inhibits the bone metastatic growth of human prostate cancer cells. [17326044]
Honokiol, a soluble nontoxic natural product derived from Magnolia spp., has been shown to induce apoptosis in malignant cells. The effect of honokiol and the combined therapy with docetaxel on prostate cancer (PCa) growth and bone metastasis was investigated in experimental models.
-   The in vitro proapoptotic effects of honokiol on human androgen-dependent and -independent PCa, bone marrow, bone marrow-derived endothelial, and prostate stroma cells were investigated. Honokiol-induced activation of caspases was evaluated by Western blot and FACS analysis. To confirm the cytotoxicity of honokiol, mice bone was inoculated in vivo with androgen-independent PCa, C4-2 cells and the effects of honokiol and/or docetaxel on PCa growth in bone were evaluated. Daily honokiol (100 mg/kg) and/or weekly docetaxel (5 mg/kg) were injected intraperitoneally for 6 weeks. PCa growth in mouse bone was evaluated by radiography, serum prostate-specific antigen (PSA) and tissue immunohistochemistry.
-   Honokiol induced apoptosis in all cell lines tested. In PCa cells honokiol induced apoptosis via the activation of caspases 3, 8, and 9 and the cleavage of poly-adenosine diphosphate ribose polymerase in a dose- and time-dependent manner. Honokiol was shown to inhibit the growth and depress serum PSA in mice harboring C4-2 xenografts in the skeleton and the combination with docetaxel showed additive effects that inhibited further growth without evidence of systemic toxicity. Immunohistochemical staining confirmed honokiol exhibited growth-inhibitory, apoptotic, and antiangiogenic effects on PCa xenografts.
-   The combination of honokiol and low-dose docetaxel may be used to improve patient outcome in androgen-independent prostate cancer with bone metastasis.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Antineoplastic Combined Chemotherapy Protocols,Apoptosis,Biphenyl Compounds,Blotting, Western,Bone Marrow Cells,Bone Neoplasms,Caspases,Cell Proliferation,Drugs, Chinese Herbal,Flow Cytometry,Humans,Immunoenzyme Techniques,Lignans,Male,Mice,Mice, Inbred BALB C,Mice, Nude,Prostate-Specific Antigen,Prostatic Neoplasms,Radiography,Taxoids,Tumor Cells, Cultured

Honokiol potentiates apoptosis, suppresses osteoclastogenesis, and inhibits invasion through modulation of nuclear factor-kappaB activation pathway. [16966432]
Recent reports have indicated that honokiol can induce apoptosis, suppress tumor growth, and inhibit angiogenesis. In this report, we found that honokiol potentiated the apoptosis induced by tumor necrosis factor (TNF) and chemotherapeutic agents, suppressed TNF-induced tumor cell invasion, and inhibited RANKL-induced osteoclastogenesis, all of which are known to require nuclear factor-kappaB (NF-kappaB) activation. Honokiol suppressed NF-kappaB activation induced by a variety of inflammatory stimuli, and this suppression was not cell type specific. Further studies showed that honokiol blocked TNF-induced phosphorylation, ubiquitination, and degradation of IkappaBalpha through the inhibition of activation of IkappaBalpha kinase and of Akt. This led to suppression of the phosphorylation and nuclear translocation of p65 and NF-kappaB-dependent reporter gene expression. Magnolol, a honokiol isomer, was equally active. The expression of NF-kappaB-regulated gene products involved in antiapoptosis (IAP1, IAP2, Bcl-x(L), Bcl-2, cFLIP, TRAF1, and survivin), proliferation (cyclin D1, cyclooxygenase-2, and c-myc), invasion (matrix metalloproteinase-9 and intercellular adhesion molecule-1), and angiogenesis (vascular endothelial growth factor) were also down-regulated by honokiol. Honokiol also down-regulated NF-kappaB activation in in vivo mouse dorsal skin model. Thus, overall, our results indicate that NF-kappaB and NF-kappaB-regulated gene expression inhibited by honokiol enhances apoptosis and suppresses osteoclastogenesis and invasion.
Mesh:Animals,Apoptosis,Biphenyl Compounds,Carrier Proteins,Cyclin D1,Cyclooxygenase 2,Dose-Response Relationship, Drug,Drug Synergism,Genes, myc,Humans,I-kappa B Proteins,Lignans,Matrix Metalloproteinase 9,Membrane Glycoproteins,Membrane Proteins,Mice,Molecular Structure,NF-KappaB Inhibitor alpha,NF-kappa B,Osteoclasts,Osteogenesis,Phosphorylation,Promoter Regions, Genetic,RANK Ligand,Receptor Activator of Nuclear Factor-kappa B,Synaptotagmin I,Tumor Necrosis Factor-alpha,Vascular Endothelial Growth Factor A

Down-regulation of P-glycoprotein expression in MDR breast cancer cell MCF-7/ADR by honokiol. [16406853]
P-glycoprotein accounts for the most intrinsic and acquired cancer multidrug resistance. To inhibit the expression of P-glycoprotein is one of the effective ways to reverse cancer drug resistance. Honokiol, a naturally occurring compound, has been demonstrated to combat cancer through mechanisms including inhibition of angiogenesis and induction of apoptosis. Here, we show that honokiol down-regulated the expression of P-glycoprotein at mRNA and protein levels in MCF-7/ADR, a human breast MDR cancer cell line. The down-regulation of P-glycoprotein was accompanied with a partial recovery of the intracellular drug accumulation, and of the sensitivities toward adriamycin. This study reveals a novel function of honokiol as an anti-cancer agent.
Mesh:ATP-Binding Cassette, Sub-Family B, Member 1,Antibiotics, Antineoplastic,Biphenyl Compounds,Breast Neoplasms,Cell Line, Tumor,Cell Survival,Dose-Response Relationship, Drug,Down-Regulation,Doxorubicin,Drug Resistance, Multiple,Drug Resistance, Neoplasm,Drug Synergism,Drugs, Chinese Herbal,Flow Cytometry,Gene Expression Regulation, Neoplastic,Humans,Lignans,Magnolia,RNA, Messenger,Rhodamine 123,Time Factors

Honokiol inhibits TNF-alpha-stimulated NF-kappaB activation and NF-kappaB-regulated gene expression through suppression of IKK activation. [16181613]
Honokiol, a small molecular weight lignan originally isolated from Magnolia officinalis, shows anti-angiogenic, anti-invasive and anti-proliferative activities in a variety of cancers. In this study, we investigated whether honokiol affects the transcription factor nuclear factor-kappa B (NF-kappaB) which controls a large number of genes involved in angiogenesis, metastasis and cell survival. We observed that the tumor necrosis factor-alpha (TNF-alpha)-induced NF-kappaB activation was blocked by honokiol in four different cancer cell lines as evidenced by EMSA. Honokiol did not directly affect the NF-kappaB-DNA binding. Immunoblot experiments demonstrated that honokiol inhibited the TNF-alpha-stimulated phosphorylation and degradation of the cytosolic NF-kappaB inhibitor IkappaBalpha. Furthermore, honokiol suppressed the intrinsic and TNF-alpha-stimulated upstream IkappaB kinases (IKKs) activities measured by a non-radioactive kinase assay using immunoprecipitated IKKs, suggesting a critical role of honokiol in abrogating the phosphorylation and degradation of IkappaBalpha. In a HeLa cell NF-kappaB-dependent luciferase reporter system, honokiol suppressed luciferase expression stimulated by TNF-alpha and by the transient transfection and expression of NIK (NF-kappaB-inducing kinase), wild type IKKbeta, constitutively active IKKalpha and IKKbeta, or the p65 subunit. Honokiol was also found to inhibit the nuclear translocation and phosphorylation of p65 subunit of NF-kappaB. RT-PCR results showed that honokiol suppressed NF-kappaB-regulated inflammatory and carcinogenic gene products including MMP-9, TNF-alpha, IL-8, ICAM-1 and MCP-1. In line with the observation that NF-kappaB activation may up-regulate anti-apoptotic genes, it was shown that honokiol enhanced TNF-alpha-induced apoptotic cell death. In summary, our results demonstrate that honokiol suppresses NF-kappaB activation and NF-kappaB-regulated gene expression through the inhibition of IKKs, which provides a possible mechanism for its anti-tumor actions.
Mesh:Antineoplastic Agents,Apoptosis,Biphenyl Compounds,Cell Line, Tumor,Electrophoretic Mobility Shift Assay,Gene Expression,Genes, Reporter,Humans,I-kappa B Kinase,Lignans,Lipopolysaccharides,Luciferases,Lymphotoxin-alpha,NF-kappa B,NF-kappa B p50 Subunit,Phosphorylation,Reverse Transcriptase Polymerase Chain Reaction,Tetradecanoylphorbol Acetate,Transcription Factor AP-1,Transcription Factor RelA,Tumor Necrosis Factor-alpha

Honokiol overcomes conventional drug resistance in human multiple myeloma by induction of caspase-dependent and -independent apoptosis. [15870175]
Honokiol (HNK) is an active component purified from magnolia, a plant used in traditional Chinese and Japanese medicine. Here we show that HNK significantly induces cytotoxicity in human multiple myeloma (MM) cell lines and tumor cells from patients with relapsed refractory MM. Neither coculture with bone marrow stromal cells nor cytokines (interleukin-6 and insulin-like growth factor-1) protect against HNK-induced cytotoxicity. Although activation of caspases 3, 7, 8, and 9 is triggered by HNK, the pan-caspase inhibitor z-VAD-fmk does not abrogate HNK-induced apoptosis. Importantly, release of an executioner of caspase-independent apoptosis, apoptosis-inducing factor (AIF), from mitochondria is induced by HNK treatment. HNK induces apoptosis in the SU-DHL4 cell line, which has low levels of caspase 3 and 8 associated with resistance to both conventional and novel drugs. These results suggest that HNK induces apoptosis via both caspase-dependent and -independent pathways. Furthermore, HNK enhances MM cell cytotoxicity and apoptosis induced by bortezomib. In addition to its direct cytotoxicity to MM cells, HNK also represses tube formation by endothelial cells, suggesting that HNK inhibits neovascurization in the bone marrow microenvironment. Taken together, our results provide the preclinical rationale for clinical protocols of HNK to improve patient outcome in MM.
Mesh:Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Bone Marrow Cells,Caspases,Cell Cycle,Cell Line, Tumor,Cell Proliferation,DNA,Dose-Response Relationship, Drug,Drug Resistance, Multiple,Endothelial Cells,Humans,Insulin-Like Growth Factor I,Interleukin-6,Lignans,Multiple Myeloma,Neovascularization, Pathologic,Stromal Cells,Structure-Activity Relationship

The natural product honokiol induces caspase-dependent apoptosis in B-cell chronic lymphocytic leukemia (B-CLL) cells. [15802533]
B-cell chronic lymphocytic leukemia (B-CLL) remains an incurable disease that requires innovative new approaches to improve therapeutic outcome. Honokiol is a natural product known to possess potent antineoplastic and antiangiogenic properties. We examined whether honokiol can overcome apoptotic resistance in primary tumor cells derived from B-CLL patients. Honokiol induced caspase-dependent cell death in all of the B-CLL cells examined and was more toxic toward B-CLL cells than to normal mononuclear cells, suggesting greater susceptibility of the malignant cells. Honokiol-induced apoptosis was characterized by the activation of caspase-3, -8, and -9 and cleavage of poly(adenosine diphosphate-ribose) polymerase (PARP). Exposure of B-CLL cells to honokiol resulted in up-regulation of Bcl2-associated protein (Bax) and down-regulation of the expression of the key survival protein myeloid-cell leukemia sequence 1 (Mcl-1), which is associated with response to treatment in B-CLL patients. In addition, B-CLL cells pretreated with interleukin-4 (IL-4), a cytokine known to support B-CLL survival, underwent apoptosis when subsequently incubated with honokiol, indicating that honokiol could also overcome the prosurvival effects of IL-4. Furthermore, honokiol enhanced cytotoxicity induced by fludarabine, cladribine, or chlorambucil. These data indicate that honokiol is a potent inducer of apoptosis in B-CLL cells and should be examined for further clinical application either as a single agent or in combination with other anticancer agents.
Mesh:Antineoplastic Agents,Apoptosis,Biphenyl Compounds,Caspases,Chlorambucil,Cladribine,Dose-Response Relationship, Drug,Drugs, Chinese Herbal,Humans,In Vitro Techniques,Interleukin-4,Leukemia, Lymphocytic, Chronic, B-Cell,Lignans,Magnolia,Myeloid Cell Leukemia Sequence 1 Protein,Neoplasm Proteins,Phytotherapy,Proto-Oncogene Proteins c-bcl-2,Vidarabine

Honokiol: a potent chemotherapy candidate for human colorectal carcinoma. [15526365]
To investigate the anticancer activity of honokiol on RKO, a human colorectal carcinoma cell line in vitro and in vivo, and to evaluate its possible use in clinic.
-   In vitro anticancer activity of honokiol was demonstrated by its induction of apoptosis in tumor cells. We analyzed cell proliferation with MTT assay, cell cycle with flow cytosmeter, DNA fragment with electrophoresis on agarose gels. To test the mechanism of honokiol-induced apoptosis, Western blotting was used to investigate the factors involved in this process. The pharmacokinetics study of honokiol was tested by high phase liquid chromatography. In in vivo study, Balb/c nude mice were incubated with RKO cells. Honokiol was injected intraperitoneally every other day into tumor bearing Balb/c nude mice.
-   Our results showed that honokiol induced apoptosis of RKO cells in a time- and dose-dependent manner. At 5-10 microg/mL for 48 h, honokiol induced apoptosis through activating Caspase cascades. Pharmacokinetics study demonstrated that, honokiol could be absorbed quickly by intraperitoneal injection, and maintained in plasma for more than 10 h. In nude mice bearing RKO-incubated tumor, honokiol displayed anticancer activity by inhibiting tumor growth and prolonging the lifespan of tumor bearing mice.
-   With its few toxicity to normal cells and potent anticancer activity in vitro and in vivo, honokiol might be a potential chemotherapy candidate in treating human colorectal carcinoma.
Mesh:Animals,Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Blotting, Western,Caspase 3,Caspase 9,Caspases,Cell Division,Cell Line, Tumor,Colorectal Neoplasms,DNA Fragmentation,Drugs, Chinese Herbal,Humans,Lignans,Mice,Mice, Inbred BALB C,Mice, Nude,Xenograft Model Antitumor Assays

Magnolol and honokiol enhance HL-60 human leukemia cell differentiation induced by 1,25-dihydroxyvitamin D3 and retinoic acid. [15474987]
Magnolol (MG) and honokiol (HK), two lignans showing anti-inflammatory and anti-oxidant properties and abundantly available in the medicinal plants Magnolia officinalis and M. obovata, were found to enhance HL-60 cell differentiation initiated by low doses of 1,25-dihydroxyvitamin D3 (VD3) and all-trans-retinoic acid (ATRA). Cells expressing membrane differentiation markers CD11b and CD14 were increased from 4% in non-treated control to 8-16% after being treated with 10-30 microM MG or HK. When added to 1 nM VD3, MG or HK increased markers expressing cells from approximately 30% to 50-80%. When either MG or HK was added to 20 nM ATRA, only CD11b, but not CD14, expressing cells were increased from 9% to 24-70%. Under the same conditions, adding MG or HK to VD3 or ATRA treatment further enlarged the G0/G1 cell population and increased the expression of p27(Kip1), a cyclin-dependent kinase inhibitor. Pharmacological studies using PD098059 (a MEK inhibitor), SB203580 (a p38 MAPK inhibitor) and SP600125 (a JNK inhibitor) suggested that the MEK pathway was important for VD3 and ATRA-induced differentiation and also its enhancement by MG or HK, the p38 MAPK pathway had a inhibitory effect and the JNK pathway had little influence. It is evident that MG and HK are potential differentiation enhancing agents which may allow the use of low doses of VD3 and ATRA in the treatment for acute promyelocytic leukemia.
Mesh:Anti-Inflammatory Agents, Non-Steroidal,Antineoplastic Agents, Phytogenic,Biphenyl Compounds,CD11b Antigen,Calcitriol,Calcium Channel Agonists,Cell Differentiation,G1 Phase,HL-60 Cells,Humans,Lignans,Lipopolysaccharide Receptors,MAP Kinase Signaling System,Resting Phase, Cell Cycle,Tretinoin

In vitro antibacterial and anti-inflammatory effects of honokiol and magnolol against Propionibacterium sp. [15288590]
Honokiol and magnolol, two major phenolic constituents of Magnolia sp., have been known to exhibit antibacterial activities. However, until now, their antibacterial activity against Propionibacterium sp. has not been reported. To this end, the antibacterial activities of honokiol and magnolol were detected using the disk diffusion method and a two-fold serial dilution assay. Honokiol and magnolol showed strong antibacterial activities against both Propionibacterium acnes and Propionibacterium granulosum, which are acne-causing bacteria. The minimum inhibitory concentrations (MIC) of honokiol and magnolol was 3-4 microg/ml (11.3-15 microM) and 9 microg/ml (33.8 microM), respectively. In addition, the killing curve analysis showed that magnolol and honokiol killed P. acnes rapidly, with 10(5) organisms/ml eliminated within 10 min of treatment with either 45 microg (169.2 microM) of magnolol or 20 microg (75.2 microM) of honokiol per ml. The cytotoxic effect of honokiol and magnolol was determined by a colorimetric (3-(4,5-dimetyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) (MTT) assay using two animal cell lines, human normal fibroblasts and HaCaT. In this experiment, magnolol exhibited lower cytotoxic effects than honokiol at the same concentration, but they showed similar cytotoxicity when triclosan was employed as an acne-mitigating agent. In addition, they reduced secretion of interleukin-8 and tumor necrosis factor alpha (TNF-alpha) induced by P. acnes in THP-1 cells indicating the anti-inflammatory effects of them. When applied topically, neither phenolic compound induced any adverse reactions in a human skin primary irritation test. Therefore, based on these results, we suggest the possibility that magnolol and honokiol may be considered as attractive acne-mitigating candidates for topical application.
Mesh:Adult,Animals,Anti-Bacterial Agents,Anti-Inflammatory Agents, Non-Steroidal,Biphenyl Compounds,Cell Line,Dose-Response Relationship, Drug,Female,Humans,Lignans,Microbial Sensitivity Tests,Propionibacterium,Skin Irritancy Tests

Honokiol induces apoptosis through p53-independent pathway in human colorectal cell line RKO. [15259066]
To investigate the signal pathway of honokiol-induced apoptosis on human colorectal carcinoma RKO cells and to evaluate whether p53 and p53-related genes were involved in honokiol-treated RKO cells.
-   Cell cycle distribution and subdiploid peak were analyzed with a flow cytometer and DNA fragment with electrophoresis on agarose gels. Transcriptional level of Bax, Bcl-2, Bid and Bcl-xl was accessed by RT-PCR. Western blotting was used to measure p53 protein expression and other factors related to apoptosis. Proliferation inhibition of two cell lines (RKO, SW480) with high expression of p53 and one cell line with p53 negative expression (LS180) was monitored by MTT assay.
-   Honokiol induced RKO cell apoptosis in a dose-dependent manner. The mRNA expression level and protein level of Bid were up-regulated while that of Bcl-xl was down-regulated, but no changes in Bax and Bcl-2 were observed. Western blotting showed p53 expression had no remarkable changes in honokiol-induced RKO cell apoptosis. LS180 cells treated with honokiol exhibited apparent growth inhibition like RKO cells and Sw480 cells.
-   Honokiol can induce RKO cells apoptosis through activating caspase cascade by p53-indepenent pathway.
Mesh:Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Cell Line, Tumor,Colorectal Neoplasms,Humans,Lignans,Tumor Suppressor Protein p53

Honokiol and magnolol induce Ca2+ mobilization in rat cortical neurons and human neuroblastoma SH-SY5Y cells. [12921862]
We examined the intracellular Ca(2+) response in primary cultured rat cortical neurons and human neuroblastoma SH-SY5Y cells by Fluo 3 fluorescence imaging analysis. In these two kinds of neuronal cells, honokiol and magnolol increased cytoplasmic free Ca(2+) with a characteristic lag phase. The cytoplasmic free Ca(2+) increase was independent of extracellular Ca(2+), but dependent on activation of phospholipase C and inositol 1,4,5-triphosphate (IP(3)) receptors. These results suggest that honokiol and magnolol increase cytoplasmic free Ca(2+) through a phospholipase C-mediated pathway, and that the release of Ca(2+) from intracellular stores mainly contributes to the increase in cytoplasmic free Ca(2+). Thus, honokiol and magnolol may be involved in a new activation mechanism closely associated with intracellular Ca(2+) mobilization.
Mesh:Animals,Biphenyl Compounds,Calcium,Cell Line, Tumor,Cells, Cultured,Cerebral Cortex,Female,Humans,Lignans,Neuroblastoma,Neurons,Pregnancy,Rats,Rats, Sprague-Dawley

Honokiol, a small molecular weight natural product, inhibits angiogenesis in vitro and tumor growth in vivo. [12816951]
Natural products comprise a major source of small molecular weight angiogenesis inhibitors. We have used the transformed endothelial cell line SVR as an effective screen of natural product extracts to isolate anti-angiogenesis and anti-tumor compounds. Aqueous extracts of Magnolia grandiflora exhibit potent activity in our SVR proliferation assays. We found that the small molecular weight compound honokiol is the active principle of magnolia extract. Honokiol exhibited potent anti-proliferative activity against SVR cells in vitro. In addition, honokiol demonstrated preferential inhibition of primary human endothelial cells compared with fibroblasts and this inhibition was antagonized by antibodies against TNF alpha-related apoptosis-inducing ligand. In vivo, honokiol was highly effective against angiosarcoma in nude mice. Our preclinical data suggests that honokiol is a systemically available and non-toxic inhibitor of angiogenesis and should be further evaluated as a potential chemotherapeutic agent.
Mesh:Angiogenesis Inhibitors,Animals,Apoptosis,Biphenyl Compounds,Cell Division,Cell Line,Cell Line, Transformed,Endothelium, Vascular,Hemangiosarcoma,Humans,Lignans,MAP Kinase Signaling System,Magnolia,Mice,Mice, Nude,Phytotherapy,Plant Extracts,Transplantation, Heterologous

Down-modulation of Bcl-XL, release of cytochrome c and sequential activation of caspases during honokiol-induced apoptosis in human squamous lung cancer CH27 cells. [12007567]
Honokiol is a phenolic compound purified from Magnolia officinalis, which induced the apoptotic cell death in several types of human cancer cells. In the present study, the molecular mechanism of honokiol-mediated apoptotic process was examined in human squamous lung cancer CH27 cells. Here, we found that honokiol-induced apoptotic cell death was accompanied by upregulation of Bad and downregulation of Bcl-XL, while honokiol had no effect on the levels of Bcl-2, Bcl-XS, Bag-1, Bax and Bak proteins. Moreover, honokiol treatment caused the release of mitochondrial cytochrome c to cytosol and sequential activation of caspases. Proteolytic activation of caspase-3 and cleavage of PARP, an in vivo substrate for caspase-3, were observed in honokiol-treated CH27 cells. Furthermore, treatment with caspase inhibitors z-DEVD-fmk and z-VAD-fmk markedly blocked honokiol-induced apoptosis. These results demonstrated that modulation of Bcl-XL and Bad proteins, release of mitochondrial cytochrome c and activation of caspase-3, participated in honokiol-triggered apoptotic process in human squamous lung cancer CH27 cells.
Mesh:Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Caspases,Cytochrome c Group,Enzyme Activation,Humans,Lignans,Lung Neoplasms,Proto-Oncogene Proteins c-bcl-2,Tumor Cells, Cultured,bcl-X Protein

Inhibitory effect of magnolol and honokiol from Magnolia obovata on human fibrosarcoma HT-1080. Invasiveness in vitro. [11731909]
We investigated the inhibitory effect of Magnolia obovata Thunb. bark ethanol extracts on human fibrosarcoma HT-1080 cells invasion in a reconstituted basement membrane [Matrigel (MG)]. We found that the effective components of the bark ethanol extracts were magnolol and honokiol, two biphenyl compounds. The extracts, magnolol and honokiol, did not affect HT-1080 cells adhesion to MG, but did inhibit HT-1080 cells migration at a high concentration (100 microM). HT-1080 cells secrete matrix metalloproteinase (MMP)-9, which degrades the extracellular matrix as a part of the invasive process. Magnolol and honokiol inhibited the activity of MMP-9, which may have been responsible, in part, for the inhibition of tumor cell invasiveness.
Mesh:Antineoplastic Agents, Phytogenic,Biphenyl Compounds,Fibrosarcoma,Humans,Lignans,Magnoliaceae,Matrix Metalloproteinase Inhibitors,Neoplasm Invasiveness,Phytotherapy,Plant Bark,Tumor Cells, Cultured

Honokiol induces apoptosis in human lymphoid leukemia Molt 4B cells. [9850734]
The exposure of human lymphoid leukemia Molt 4B cells to honokiol led to both growth inhibition and the induction of apoptosis. Morphological change showing apoptotic bodies was observed in the cells treated with honokiol. The fragmentation by honokiol of DNA to oligonucleosomal-sized fragments that are characteristics of apoptosis was observed to be concentration- and time-dependent. These findings suggest that growth inhibition by honokiol of Molt 4B cells results from the induction of apoptosis in the cells.
Mesh:Antineoplastic Agents, Phytogenic,Apoptosis,Biphenyl Compounds,Cell Division,Dose-Response Relationship, Drug,Humans,Leukemia, Lymphoid,Lignans,Tumor Cells, Cultured


[Study on transport characteristics of honokiol in Caco-2 cell model by HPLC]. [21837966]
To study the transport mechanism of honokiol in Caco-2 cell model.
-   The analysis was performed on a Kromasil 100-5 C18 column (4.5 mm x 250 mm, 5 microm) eluted with acetonitrile-water (70: 30) as mobile phase. The detection wavelength was set at 203 nm. Two-way transport of honokiol was studied by using Caco-2 cell model, and the effects of time, drug concentration, inhibitor, pH, temperature on the transport of honokiol was investigated. The drug concentrations were determined by high performance liquid chromatography(HPLC) and used to calculate the apparent permeability coefficient.
-   The standard curve of honokiol was Y = 24 044X - 3 763.6 (r = 0.999 8), and the detection limit was 0.04 micromol x L(-1). In Caco-2 cell model, the transport amounts from the top side to the base side of were more than that from the base side to the top side under the same concentration. The transport amounts increased with time both in AP --> BL and BL --> AP directions. Verapamil could improve the transport amounts of AP --> BL. There were no effects of pH on the transport of AP --> BL. Both in AP --> BL and BL --> AP directions, the transport showed temperature dependence.
-   Honokiol is transported through the intestinal mucosa via a passive diffusion mechanism primarily, coexisting with a carrier-mediated transport, at the same time effected by P-gp.
Mesh:Biological Transport,Biphenyl Compounds,Caco-2 Cells,Chromatography, High Pressure Liquid,Diffusion,Humans,Lignans,Permeability
  • Honokiol is transported through the intestinal mucosa via a passive diffusion mechanism primarily

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