lignans and Liver-Neoplasms

Liver injury is a common pathological process characterized by massive degeneration and abnormal death of liver cells. With increase in dead cells and necrosis, liver injury eventually leads to nonalcoholic fatty liver disease (NAFLD), hepatic fibrosis, and even hepatocellular carcinoma (HCC). Consequently, it is necessary to treat liver injury and to prevent its progression. The drug Bicylol is widely employed in China to treat chronic hepatitis B virus (HBV) and has therapeutic potential for liver injury. It is the derivative of dibenzocyclooctadiene lignans extracted from Schisandra chinensis (SC). The Schisandraceae family is a rich source of dibenzocyclooctadiene lignans, which possesses potential liver protective activity. This study aimed to comprehensively summarize the phytochemistry, structure-activity relationship and molecular mechanisms underlying the liver protective activities of dibenzocyclooctadiene lignans from the Schisandraceae family. Here, we had discussed the analysis of absorption or permeation properties of 358 compounds based on Lipinski's rule of five. So far, 358 dibenzocyclooctadiene lignans have been reported, with 37 of them exhibited hepatoprotective effects. The molecular mechanism of the active compounds mainly involves antioxidative stress, anti-inflammation and autophagy through Kelch-like ECH-associating protein 1/nuclear factor erythroid 2 related factor 2/antioxidant response element (Keap1/Nrf2/ARE), nuclear factor kappa B (NF-кB), and transforming growth factor β (TGF-β)/Smad 2/3 signaling pathways. This review is expected to provide scientific ideas for future research related to developing and utilizing the dibenzocyclooctadiene lignans from Schisandraceae family.

Topics: Carcinoma, Hepatocellular; Hepatitis B, Chronic; Humans; Kelch-Like ECH-Associated Protein 1; Lignans; Liver Neoplasms; NF-E2-Related Factor 2; NF-kappa B; Schisandraceae; Structure-Activity Relationship

Pyroptosis, an inflammatory programmed cell death, has been suggested as a novel molecular mechanism for the treatment of hepatocellular carcinoma (HCC) with chemotherapeutic agents. Recent studies showed that natural killer (NK) cells could inhibit apoptosis and regulate the progression of pyroptosis in tumor cells. Schisandrin B (Sch B), a lignan isolated from Schisandrae chinensis (Turcz.) Baill. (Schisandraceae) Fructus, has various pharmacological activities including anti-cancer effects. The purpose of this study was to investigate the effect of NK cells on Sch B's regulation of pyroptosis in HCC cells and the molecular mechanisms implicated. The results showed that Sch B alone could decrease cell viability and induce apoptosis in HepG2 cells. However, Sch B induced apoptosis in HepG2 cells was transformed into pyroptosis in the presence of NK cells. The mechanisms underlying NK cell's effect on pyroptosis in Sch B-treated HepG2 cells was related to its activation of caspase 3-Gasdermin E (GSDME). Further studies revealed that NK cell induced caspase 3 activation was derived from its activation of perforin-granzyme B pathway. This study explored the effect of Sch B and NK cells on pyroptosis in HepG2 cells and revealed that perforin-granzyme B-caspase 3-GSDME pathway is involved in the process of pyroptosis. These results proposed an immunomodulatory mechanism of Sch B on HepG2 cells pyroptosis and suggested Sch B as a promising immunotherapy combination partner for the treatment of HCC.

Topics: Carcinoma, Hepatocellular; Caspase 3; Hep G2 Cells; Humans; Killer Cells, Natural; Lignans; Liver Neoplasms; Pyroptosis

Despite the advances in developing MMP-2/9 inhibitors, off-target side effects and pharmacokinetics problems remain major challenges hindering their clinical success in cancer therapy. However, recent targeting strategies have clearly revitalized MMP research. Herein, we introduce new s-triazine-based dendrimers endowed with intrinsic MMP-2/9 inhibitory potential and tetherable to hepatocellular carcinoma-specific targeting ligands and anticancer agents via biodegradable linkages for targeted therapy. The designed dendrimeric platform was built with potential zinc-binding branching linkers (hydrazides) and termini (carboxylic acids and hydrazides) to confer potency against MMP-2/9. Preliminary cytotoxicity screening and MMP-2/9 inhibition assay of the free dendrimers revealed promising potency (MMP-9; IC

Topics: Antineoplastic Agents; Apoptosis; Biphenyl Compounds; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Proliferation; Dendrimers; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Humans; Lignans; Liver Neoplasms; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Matrix Metalloproteinase Inhibitors; Molecular Structure; Structure-Activity Relationship; Triazines

Liver cancer is a critical clinical condition with augmented malignancy, rapid progression, and poor prognosis. Liver cancer often initiates as fibrosis, develops as cirrhosis, and results in cancer. For centuries, medicinal plants have been incorporated in various liver-associated complications, and recently, research has recognized that many bioactive compounds from medicinal plants may interact with targets related to liver disorders. Phyllanthin from the Phyllanthus species is one such compound extensively used by folklore practitioners for various health benefits. However, most practices continue to be unrecognized scientifically. Hence, in this work, we investigated the protective role of phyllanthin on diethylnitrosamine (DEN) induced liver carcinoma in Wistar Albino rats and the anti-tumor potential on human hepatocellular carcinoma (HCC) HepG2 cells. The DEN-challenged liver cancer in experimental rats caused increased liver weight, 8-OHD, hepatic tissue injury marker, lipid peroxidation, and tumor markers levels. Remarkably, phyllanthin counteracted the DEN effect by ameliorating all the liver function enzymes, oxidative DNA damage, and tumor-specific markers by enhanced anti-oxidant capacity and induced caspase-dependent apoptosis through the mTOR/ PI3K signaling pathway. MTT assay demonstrated that phyllanthin inhibited the HepG2 cell growth in a dose-dependent manner. Fascinatingly, phyllanthin did not demonstrate any substantial effect on the normal cell line, HL7702. In addition, HepG2 cells were found in the late apoptotic stage upon treatment with phyllanthin as depicted by acridine orange/ethidium bromide staining. Overall, this work offers scientific justification that phyllanthin can be claimed to be a safe candidate with potential chemotherapeutic activity against HCC.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antineoplastic Agents, Phytogenic; Antioxidants; Apoptosis; Biomarkers, Tumor; Body Weight; Cell Survival; Diethylnitrosamine; Disease Models, Animal; Hep G2 Cells; Humans; Lignans; Liver Neoplasms; Male; Oxidative Stress; Phosphatidylinositol 3-Kinase; Proto-Oncogene Proteins c-akt; Rats, Wistar; TOR Serine-Threonine Kinases

Hepatocellular carcinoma (HCC) is the fifth common types of cancer with poor prognosis in the world. Honokiol (HNK), a natural biphenyl compound derived from the magnolia plant, has been reported to exert anticancer effects, but its mechanism has not been elucidated exactly. In the present study, HNK treatment significantly suppressed the migration ability of HepG2 and Hep3B human hepatocellular carcinoma. The treatment reduced the expression levels of the genes associated with cell migration, such as S100A4, MMP-2, MMP-9 and Vimentin. Interestingly, treatment with HNK significantly reduced the expression level of Cyclophilin B (CypB) which stimulates cancer cell migration. However, overexpressed CypB abolished HNK-mediated suppression of cell migration, and reversed the apoptotic effects of HNK. Altogether, we concluded that the suppression of migration activities by HNK was through down-regulated CypB in HCC. These finding suggest that HNK may be a promising candidate for HCC treatment via regulation of CypB.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Biphenyl Compounds; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Movement; Cell Survival; Cyclophilins; Down-Regulation; Gene Expression Regulation, Neoplastic; Hep G2 Cells; Humans; Lignans; Liver Neoplasms; Signal Transduction

Arctigenin (ARG) has been proved to inhibit the viability of hepatocellular carcinoma (HCC) via inducing apoptosis. However, the precise mechanism remains unknown. The present study was aimed to further investigate the mechanism of ARG against HCC in vitro and in vivo.. Arctigenin was applied in vitro and in vivo. Western blotting, immunohistochemistry, etc., were used to investigate the mechanisms.. The time-dependent enhancement of Bax/Bcl-2 ratio, cytochrome c release, Fas and FasL levels, caspase cascade activation and the loss in the mitochondrial out membrane potential indicated that both intrinsic and extrinsic apoptotic pathways were triggered by ARG. Moreover, Jun NH2-terminal kinase (JNK) and p38 phosphorylated time-dependently. And inhibition of the phosphorylation of either p38 or JNK led to a significant reduction in HepG2 apoptosis, owing to the crucial roles of p38 and JNK played in regulating the apoptosis pathways. In addition, ARG increased the generation of reactive oxygen species (ROS) in HepG2 cells, while the antioxidant N-acetyl cysteine almost reversed ARG-induced JNK and p38 activation, and dramatically decreased cell apoptosis. In vivo, ARG increased the cell apoptosis in tumour tissues, and p-p38, p-JNK and Bax were significantly upregulated.. Our findings demonstrated that ARG induced apoptosis in HCC via ROS-mediated mitogen-activated protein kinases apoptosis pathway.

Topics: Animals; Antineoplastic Agents; Apoptosis; Apoptosis Regulatory Proteins; Carcinoma, Hepatocellular; Enzyme Activation; Furans; Hep G2 Cells; Humans; Lignans; Liver Neoplasms; Mice, Inbred BALB C; Mice, Nude; Mitogen-Activated Protein Kinases; Reactive Oxygen Species; Signal Transduction; Tumor Burden; Xenograft Model Antitumor Assays

Autophagy is a catabolic process that degrades dysfunctional proteins and organelles and plays critical roles in cancer development. Our preliminary screening identified that extracts of the fruits of Arctium lappa and the fruits of Forsythia suspensa notably suppressed the proliferation of hepatocellular carcinoma HepG2 cells and downregulated the autophagy. In this study, we explored the effect of arctigenin (ARG), a bioactive lignan in both extracts, on cell proliferation and autophagy-related proteins in HepG2 cells. ARG inhibited the proliferation of HepG2 cells. Analysis of autophagy-related proteins demonstrated that ARG might block the autophagy that leads to sequestosome 1/p62 (p62) accumulation. The stage of inhibition in autophagy by ARG differed from those by the autophagy inhibitors 3-methyladenine (3-MA) or chloroquine (CQ). ARG could also inhibit starvation-induced autophagy. Further analysis of apoptosis-related proteins indicated that ARG did not affect caspase-3 activation and PARP cleavage, suggesting that the antiproliferative effect of ARG can occur independently of apoptosis. In summary, our study showed that ARG suppresses cell proliferation and inhibits autophagy, and might lead to the development of agents for autophagy research and cancer chemoprevention.

Topics: Adenine; Apoptosis; Apoptosis Regulatory Proteins; Arctium; Autophagy; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Proliferation; Chloroquine; Forsythia; Furans; Hep G2 Cells; Humans; Lignans; Liver Neoplasms; Sequestosome-1 Protein

Primary liver cancer is a lethal cancer. The phosphatidylinositol 3-kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) pathway has been implicated in the pathogenesis of liver cancer. Gomisin N (GN), a lignan isolated from the dried fruits of Schisandra chinensis (Turca.) Baill., has been reported to reduce viability of, and induce apoptosis in, HepG2 liver cancer cells. In preadipocytes, GN was found to inhibit Akt activity. In the present study, Akt signaling-related anti-liver cancer mechanisms of GN were investigated. We confirmed that GN reduces cell viability of, and triggers apoptosis in, more liver cancer cell lines. Mechanistic studies revealed that GN lowers protein levels of phospho-PI3K (p85 tyrosine (Tyr)458), phospho-Akt (serine (Ser)473), and Akt downstream molecules Mcl-1 in HepG2 and HCCLM3 cells. Meanwhile, GN activates mTOR and inhibits ULK1 (a negative downstream effector of mTOR) activities. Activation of mTOR has been reported to suppress ULK1 activity and repress autophagy. Indeed, we observed that GN inhibits autophagy in liver cancer cells. In summary, we for the first time demonstrated that GN inhibits the PI3K-Akt pathway and regulates the mTOR-ULK1 pathway in liver cancer cells.

Topics: Antineoplastic Agents; Autophagy-Related Protein-1 Homolog; Cell Line, Tumor; Cyclooctanes; Humans; Intracellular Signaling Peptides and Proteins; Lignans; Liver Neoplasms; Phosphatidylinositol 3-Kinase; Polycyclic Compounds; Proto-Oncogene Proteins c-akt; Signal Transduction; TOR Serine-Threonine Kinases

Arctigenin has been shown to have anti-tumor effects in various types of cancers. This study was conducted to verify these effects in the human-derived hepatoblastoma cell line, HUH-6 clone 5 (hereinafter, HUH-6).. Arctigenin was added to cultured HUH-6 cells, and cellular activity was evaluated by MTS assay. To determine the relationship between reduced cellular activity and apoptosis, we measured the activities of caspase 3/7, 8, and 9 and conducted flow cytometry with Annexin V/PI staining.. We found that arctigenin has anti-tumor effects in HUH-6 cells in a concentration-dependent manner. Arctigenin may have exerted its anti-tumor effect by inducing apoptosis via TNFR1, which recruits Complex IIa to activate caspase 8 and 3/7. These results may be useful for developing therapeutic agents for hepatoblastoma.

Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cells, Cultured; Furans; Hepatoblastoma; Humans; Lignans; Liver Neoplasms

Arctigenin (ARG) is famous in its abundant pharmacological activity. However, many researches in it entered the bottleneck period because of its poor water solubility. The derivatives of ARG have been synthesised with five amino acids which have t-Butyloxy carbonyl (BOC) as a protective group. We examined the effects of removing BOC. The results showed that the amino acid derivatives without protective group have better water solubility and nitrite-clearing ability than ARG. Based on these results, ARG6' and ARG9' were selected at a dosage of 40 mg/kg to evaluate their antitumour activity. The percentage inhibition rate of ARG6' and ARG9' were 55.87 and 51.40, respectively, which was twice as much as ARG. Furthermore, they could increase liver and kidney indexes and produce less damage in these organs. In brief, this study provides a basis for new drug development.

Topics: Amino Acids; Animals; Antineoplastic Agents; Carcinoma, Hepatocellular; Chemistry Techniques, Synthetic; Drug Screening Assays, Antitumor; Esters; Furans; Humans; Lignans; Liver Neoplasms; Mice, Inbred ICR; Nitrites; Solubility; Structure-Activity Relationship; Xenograft Model Antitumor Assays

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.

Topics: 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

This study aims to design a novel nano-sized anticancer drug delivery system that can enhance the therapeutic effects of the loaded drug. With this idea in mind, this work reported the design and characterization of epigallocatechin-3-gallate (EGCG) functionalized chitin (CH) derivative, and its application in nano-drug delivery system. The EGCG-functionalized CH (CE) polymer was firstly prepared and characterized. The nanoparticles (NPs) of CE-loaded honokiol (HK), which was prepared by ionic crosslinking, exhibited a size of 80 nm, zeta potential of +33.8 mV, and spherical morphology. The antitumor activity of the CE-HK NPs in vitro and in vivo was investigated and compared to free HK. As a result, the CE-HK NPs can effectively inhibited cell proliferation of HepG2 cell by inhibiting more cells in the G2/M phase and decreasing mitochondrial membrane potential. The CE-HK NPs (40 mg/kg) inhibited tumor growth by 83.55% (p < 0.05), which was far higher than the 30.15% inhibition of free HK (40 mg/kg). The proposed delivery system exhibits better tumor selectivity and growth reduction both in vitro and in vivo, and does not induce any side effects. Therefore, the CE-HK NPs may act as an effective delivery system of liver cancer agent HK.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Biphenyl Compounds; Carcinoma, Hepatocellular; Catechin; Cell Proliferation; Chitin; Cross-Linking Reagents; Dose-Response Relationship, Drug; Drug Carriers; Drug Compounding; Drug Liberation; G2 Phase Cell Cycle Checkpoints; Hep G2 Cells; Humans; Kinetics; Lignans; Liver Neoplasms; Male; Membrane Potential, Mitochondrial; Mice, Inbred BALB C; Nanoparticles; Nanotechnology; Particle Size; Solubility; Surface Properties; Technology, Pharmaceutical; Tumor Burden; Xenograft Model Antitumor Assays

Topics: Animals; Apoptosis; Biphenyl Compounds; Carcinoma, Hepatocellular; Cell Line, Tumor; Hep G2 Cells; Humans; Lignans; Liver Neoplasms; MAP Kinase Signaling System; Mice; Mice, Nude; TNF-Related Apoptosis-Inducing Ligand

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.

Topics: Animals; Antineoplastic Agents; Apoptosis; Biphenyl Compounds; Carcinoma, Hepatocellular; cdc42 GTP-Binding Protein; Cell Cycle; Cell Line, Tumor; Cell Movement; Cell Proliferation; Disease Models, Animal; ErbB Receptors; 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; rac1 GTP-Binding Protein; Signal Transduction; Zebrafish

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.

Topics: Antineoplastic Agents, Phytogenic; Biphenyl Compounds; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Proliferation; G1 Phase Cell Cycle Checkpoints; Humans; Lignans; Liver Neoplasms; PPAR gamma; Rosiglitazone; Thiazolidinediones

Lariciresinol (LA) is a traditional Chinese medicine possessing anticancer activity, but its mechanism of action remains unclear. The present study explored the effects of LA on human HepG2 cells and the underlying mechanism. Our data indicated that LA inhibited cell proliferation and induced cell cycle arrest in S phase, subsequently resulting in apoptosis in HepG2 cells. Using a proteomics approach, eight differentially expressed proteins were identified. Among them, three proteins, glyceraldehyde-3-phosphate, UDP-glucose 4-epimerase, and annexin A1, were upregulated, while the other five proteins, heat shock protein 27, haptoglobin, tropomodulin-2, tubulin alpha-1A chain, and brain acid soluble protein 1, were downregulated; all of these proteins are involved in cell proliferation, metabolism, cytoskeletal organization, and movement. Network analysis of these proteins suggested that the ubiquitin-conjugating enzyme (UBC) plays an important role in the mechanism of LA. Western blotting confirmed downregulation of heat shock protein 27 and upregulation of ubiquitin and UBC expression levels in LA-treated cells, consistent with the results of two-dimensional electrophoresis and a STRING software-based analysis. Overall, LA is a multi-target compound with anti-cancer effects potentially related to the ubiquitin-proteasome pathway. This study will increase our understanding of the anticancer mechanisms of LA.

Topics: Amino Acid Sequence; Antineoplastic Agents, Phytogenic; Apoptosis; Carcinoma, Hepatocellular; Cell Cycle; Cell Proliferation; Furans; Hep G2 Cells; Hepatocytes; Humans; Lignans; Liver Neoplasms; Patrinia; Protein Interaction Maps; Proteome; Proteomics

Gomisin G, isolated from herb Schisandra chinensis, exhibits anti-tumor activities. Therefore, Gomisin G is a drug candidate for anti-liver cancer therapy.. To predict the metabolic behavior and metabolism-based drug-drug interaction of gomisin G.. Molecular docking method was used. The crystal structure of CYP3A4 with the ligand ketoconazole was chosen from protein data bank (http://www.rcsb.org/pdb). Chemdraw software was used to draw the two-dimensional structure of gomisin G with standard bond lengths and angles.. Gomisin G can be well docked into the activity site of CYP3A4, and distance between gomisin G the heme active site was 2.75 Å. To evaluate whether the inhibitors of CYP3A4 can affect the metabolism of gomisin G, co-docking of gomisin G and ketoconazole was further performed. The distance between ketoconazole and activity center (2.10 Å) is closer than the distance between gomisin G and activity center of CYP3A4, indicating the easy influence of CYP3A4's strong inhibitor towards the metabolism of gomisin G.. Gomisin G is a good substrate of CYP3A4, and CYP3A4 inhibitors easily affect the metabolism of Gomisin G.

Topics: Antineoplastic Agents; Cyclooctanes; Cytochrome P-450 CYP3A; Cytochrome P-450 CYP3A Inhibitors; Dioxoles; Drug Interactions; Humans; Ketoconazole; Lignans; Liver; Liver Neoplasms; Molecular Docking Simulation; Plant Extracts; Schisandra

Twelve novel 7'-hydroxy lignan glucosides (1-12), including two benzofuran-type neolignans, two 8-O-4' neolignans, two dibenzylbutyrolactone lignans, and six tetrahydrofuranoid lignans, together with six known lignan glucosides (13-18), were isolated from the fruit of Arctium lappa L. (Asteraceae), commonly known as Arctii Fructus. Their structures were elucidated using spectroscopy (1D and 2D NMR, MS, IR, ORD, and UV) and on the basis of chemical evidence. The absolute configurations of compounds 1-12 were confirmed using rotating frame nuclear overhauser effect spectroscopy (ROESY), the circular dichroic (CD) exciton chirality method, and Rh2(OCOCF3)4-induced CD spectrum analysis. All of the isolated compounds were tested for hepatoprotective effects against D-galactosamine-induced cytotoxicity in HL-7702 hepatic cells. Compounds 1, 2, 7-12, and 17 showed significantly stronger hepatoprotective activity than the positive control bicyclol at a concentration of 1 × 10(-5) M.

Topics: Apoptosis; Arctium; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Proliferation; Chemical and Drug Induced Liver Injury; Circular Dichroism; Drugs, Chinese Herbal; Fruit; Glucosides; Humans; Lignans; Liver Neoplasms; Magnetic Resonance Spectroscopy; Molecular Structure

Limited epidemiological evidence suggests a protective role for plant foods rich in flavonoids and antioxidants in hepatocellular cancer (HCC) etiology. Our aim was to prospectively investigate the association between dietary intake of flavonoids, lignans and nonenzymatic antioxidant capacity (NEAC) and HCC risk. Data from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort including 477,206 subjects (29.8% male) recruited from ten Western European countries, was analyzed. Flavonoid, lignan and NEAC intakes were calculated using a compilation of existing food composition databases linked to dietary information from validated dietary questionnaires. Dietary NEAC was based on ferric reducing antioxidant capacity (FRAP) and total radical-trapping antioxidant parameter (TRAP). Hepatitis B/C status was measured in a nested case-control subset. During a mean follow-up of 11-years, 191 incident HCC cases (66.5% men) were identified. Using Cox regression, multivariable adjusted models showed a borderline nonsignificant association of HCC with total flavonoid intake (highest versus lowest tertile, HR = 0.65, 95% CI: 0.40-1.04; p(trend) = 0.065), but not with lignans. Among flavonoid subclasses, flavanols were inversely associated with HCC risk (HR = 0.62, 95% CI: 0.39-0.99; p(trend) = 0.06). Dietary NEAC was inversely associated with HCC (FRAP: HR 0.50, 95% CI: 0.31-0.81; p(trend) = 0.001; TRAP: HR 0.49, 95% CI: 0.31-0.79; p(trend) = 0.002), but statistical significance was lost after exclusion of the first 2 years of follow-up. This study suggests that higher intake of dietary flavanols and antioxidants may be associated with a reduced HCC risk.

Topics: Antioxidants; Carcinoma, Hepatocellular; Case-Control Studies; Cohort Studies; Diet; Europe; Feeding Behavior; Female; Flavonoids; Follow-Up Studies; Humans; Lignans; Liver Neoplasms; Male; Middle Aged; Nutritional Status; Prospective Studies; Risk; Risk Assessment; Risk Factors; Surveys and Questionnaires

Sesamin, one of the most abundant lignans in sesame seeds, has been shown to exhibit various pharmacological effects. The aim of this study was to elucidate whether sesamin promotes cell cycle arrest and induces apoptosis in HepG2 cells and further to explore the underlying molecular mechanisms. Here, we found that sesamin inhibited HepG2 cell growth by inducing G2/M phase arrest and apoptosis. Furthermore, sesamin suppressed the constitutive and interleukin (IL)-6-induced signal transducer and activator of transcription 3 (STAT3) signalling pathway in HepG2 cells, leading to regulate the downstream genes, including p53, p21, cyclin proteins and the Bcl-2 protein family. Our studies showed that STAT3 signalling played a key role in sesamin-induced G2/M phase arrest and apoptosis in HepG2 cells. These findings provided a molecular basis for understanding of the effects of sesamin in hepatocellular carcinoma tumour cell proliferation. Therefore, sesamin may thus be a potential chemotherapy drug for liver cancer.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Carcinoma, Hepatocellular; Cell Cycle; Cell Cycle Checkpoints; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Dioxoles; Gene Expression Regulation, Neoplastic; Hep G2 Cells; Humans; Interleukin-6; Lignans; Liver Neoplasms; Phytotherapy; Plant Extracts; Seeds; Sesamum; Signal Transduction; STAT3 Transcription Factor; Tumor Suppressor Protein p53

Non-small-cell lung cancer (NSCLC) represents approximately 80% of all types of lung cancer. Here, we report the chemotherapeutic effect of honokiol, a phytochemical from Magnolia grandiflora, on NSCLC cells and the molecular mechanisms underlying these effects using in vitro and in vivo models. Treatment of NSCLC cells (A549, H1299, H460 and H226) with honokiol (20, 40 and 60 µM) inhibited histone deacetylase (HDAC) activity, reduced the levels of class I HDAC proteins and enhanced histone acetyltransferase activity in a dose-dependent manner. These effects of honokiol were associated with a significant reduction in the viability of NSCLC cells. Concomitant treatment of cells with a proteasome inhibitor, MG132, prevented honokiol-induced degradation of class I HDACs, suggesting that honokiol reduced the levels of HDACs in NSCLC cells through proteasomal degradation. Valproic acid, an inhibitor of HDACs, exhibited a similar pattern of reduced viability and induction of death of NSCLC cells. Treatment of A549 and H1299 cells with honokiol resulted in an increase in G 1 phase arrest, and a decrease in the levels of cyclin D1, D2 and cyclin dependent kinases. Further, administration of honokiol by oral gavage significantly inhibited the growth of subcutaneous A549 and H1299 tumor xenografts in athymic nude mice, which was associated with the induction of apoptotic cell death and marked inhibition of class I HDACs proteins and HDAC activity in the tumor xenograft tissues. Together, our study provides new insights into the role of class I HDACs in the chemotherapeutic effects of honokiol on lung cancer cells.

Topics: Acetylation; Animals; Biphenyl Compounds; Bronchi; Carcinoma, Non-Small-Cell Lung; Cell Death; Cell Line, Tumor; Cell Proliferation; Cell Survival; Epithelial Cells; G1 Phase Cell Cycle Checkpoints; Histone Acetyltransferases; Histone Deacetylase Inhibitors; Histone Deacetylases; Histones; Hydroxamic Acids; Lignans; Liver Neoplasms; Mice; Mice, Nude; Proteasome Endopeptidase Complex; Proteolysis; Valproic Acid; Xenograft Model Antitumor Assays

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.

Topics: Antineoplastic Agents, Phytogenic; Biphenyl Compounds; Carcinoma, Hepatocellular; Caspase 3; Cell Line, Tumor; Cell Proliferation; Cell Survival; CSK Tyrosine-Protein Kinase; 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; Signal Transduction; src-Family Kinases; STAT3 Transcription Factor

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.

Topics: 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

Aster flaccidus bge has been used as traditional medicine in northwestern China. Two new phenylpropanoids (1-2) including one lignan: (7'R, 8S)-9'-lariciresinol-(alpha-methyl)-butanoate (1), 5,9-dimethoxyl-7-(alpha-methyl)-butanoxyl-phenyl-2E-propenol-(alpha-methyl)-butanoate (2) isolated from the chloroform extract of the root of Aster flaccidus bge were identified by means of extensive spectroscopic studies: 1D and 2D NMR spectra as well as HRMS analysis. They have not obvious anti-HIV-1 therapeutic activity (TI=1.0-1.1) compared with AZT (TI=55,556) as the result of the determination of their in vitro anti-HIV-1 activity while compound 2 displays strong antitumor activity against BEL 7402 (human liver carcinoma) with cisplatin as a positive control and the effect increases with the measuring-time going on (24 h, IC(50): 106.67+/-8.47 microM - 72 h, IC(50): 50.51+/-6.11 microM).

Topics: Antineoplastic Agents, Phytogenic; Aster Plant; Cell Line, Tumor; Cisplatin; HIV Infections; HIV-1; Humans; Lignans; Liver Neoplasms; Phenylpropionates; Phytotherapy; Plant Extracts

The upregulation of phase II detoxification genes is believed to play an important role in cancer prevention. The molecular mechanism underlying the changes in gene expression that accompany cancer prevention involves activation of the transcription factor, NF-E2-related factor 2 (Nrf2). In traditional medicine, the fruit of Schisandra chinensis Baill is used as a tonic, an anti-tussive and an anti-aging drug. In the current study, nine lignans were isolated from S. chinensis and tested for their ability to induce quinone reductase (QR) activity in Hepa1c1c7 mouse hepatocarcinoma cells. Tigloylgomisin H (TGH) and angeloylgomisin H (AGH) significantly induced QR activity and exhibited a relatively high chemoprevention index (CI) (10.80 and 4.59, respectively) as compared to control. TGH also induced QR activity in BPrc1 mouse hepatocarcinoma cells as well, which are defective in aryl hydrocarbon nuclear translocator (Arnt). In HepG2 human hepatocarcinoma cells, TGH significantly activated gene expression mediated by the antioxidant response element (ARE), a key regulatory region in the promoters of detoxification enzymes, through the nuclear accumulation of Nrf2. The results of the current study suggest that TGH functions as a novel monofunctional inducer that specifically upregulates phase II enzymes through the Nrf2-ARE pathway. TGH thus represents a potential liver cancer prevention agent.

Topics: Animals; Anticarcinogenic Agents; Carcinoma, Hepatocellular; Cell Line, Tumor; Fruit; Humans; Lignans; Liver Neoplasms; Metabolic Detoxication, Phase II; Mice; NAD(P)H Dehydrogenase (Quinone); NADPH Dehydrogenase; NF-E2-Related Factor 2; Schisandra

Taiwanin A, a lignan isolated from Taiwania cryptomerioides Hayata, has previously been reported to have cytotoxicity against human tumor cells, but the mechanisms are unclear. In this study, we examined the molecular mechanism of cell death of human hepatocellular carcinoma HepG2 cells induced by Taiwanin A. Taiwanin A has been found to induce cell cycle arrest at G2/M phase as well as caspase-3-dependent apoptosis within 24 h. We performed both in vitro turbidity assay and immunofluorescence staining of tubulin to show that Taiwanin A can inhibit microtubule assembly. Moreover, the tumor suppressor protein p53 in HepG2 cells was activated by Taiwanin A within 12 h. Inhibition of p53 by either pifithrin-alpha or by short hairpin RNA which blocks p53 expression attenuates Taiwanin A cytotoxicity. Our results demonstrate that Taiwanin A can act as a new class of microtubule damaging agent, arresting cell cycle progression at mitotic phase and inducing apoptosis through the activation of p53.

Topics: Apoptosis; Carcinoma, Hepatocellular; Cell Cycle; Cell Division; Cell Line, Tumor; Cell Survival; Furans; G2 Phase; Humans; Lignans; Liver Neoplasms; Microtubule Proteins; Spindle Apparatus; Tumor Suppressor Protein p53

Tumor cells generally proliferate rapidly and the demand for essential nutrients as well as oxygen always exceeds the supply due to the unregulated growth and the insufficient and inappropriate vascular supply. However, cancer cells show an inherent ability to tolerate extreme conditions, such as that characterized by low nutrient and oxygen supply, by modulating their energy metabolism. Thus, targeting nutrient-deprived cancer cells may be a novel strategy in anticancer drug development. Based on that, we established a novel screening method to discover anticancer agents that preferentially inhibit cancer cell viability under the nutrient-deprived condition. After screening 500 medicinal plant extracts used in Japanese Kampo medicine, we found that a CH(2)Cl(2)-soluble extract of Arctium lappa exhibited 100% preferential cytotoxicity under the nutrient-deprived condition at a concentration of 50 microg/mL with virtually no cytotoxicity under nutrient-rich condition. Further bioassay-guided fractionation and isolation led to the isolation of arctigenin as the primary compound responsible for such preferential cytotoxicity; the compound exhibited 100% preferential cytotoxicity against nutrient-deprived cells at a concentration of 0.01 microg/mL. Furthermore, arctigenin was also found to strongly suppress the PANC-1 tumor growth in nude mice, as well as the growth of several of the tested pancreatic cancer cell lines, suggesting the feasibility of this novel antiausterity approach in cancer therapy. Further investigation of the mechanism of action of arctigenin revealed that the compound blocked the activation of Akt induced by glucose starvation, which is a key process in the tolerance exhibited by cancer cells to glucose starvation.

Topics: Animals; Antineoplastic Agents, Phytogenic; Arctium; Carcinoma, Hepatocellular; Cell Line, Tumor; Drug Screening Assays, Antitumor; Female; Furans; Glucose; Humans; Lignans; Liver Neoplasms; Mice; Mice, Inbred BALB C; Mice, Nude; Pancreatic Neoplasms; Phosphorylation; Proto-Oncogene Proteins c-akt; Xenograft Model Antitumor Assays

Justicia procumbens is a traditional Taiwanese herbal remedy used to treat fever, pain, and cancer. Justicidin A, isolated from Justicia procumbens, has been reported to suppress in vitro growth of several tumor cell lines as well as hepatoma cells. In this study, justicidin A activated caspase-8 to increase tBid, disrupted mitochondrial membrane potential (Delta psi(m)), and caused the release of cytochrome c and Smac/DIABLO in Hep 3B and Hep G2 cells. Justicidin A also reduced Bcl-x(L) and increased Bax and Bak in mitochondria. Caspase-8 inhibitor (Z-IETD) attenuated the justicidin A-induced disruption of Delta psi(m). Growth of Hep 3B implanted in NOD-SCID mice was suppressed significantly by oral justicidin A (20 mg/kg/day). These results indicate that justicidin A-induced apoptosis in these cells proceeds via caspase-8 and is followed by mitochondrial disruption.

Topics: Animals; Apoptosis; Apoptosis Regulatory Proteins; Carcinoma, Hepatocellular; Caspase 8; Caspases; Cell Proliferation; Cytochromes c; Dioxolanes; Down-Regulation; Enzyme Activation; Humans; Intracellular Signaling Peptides and Proteins; Lignans; Liver Neoplasms; Mice; Mice, Inbred NOD; Mice, SCID; Mitochondria; Mitochondrial Proteins; Proto-Oncogene Proteins c-bcl-2; Up-Regulation; Xenograft Model Antitumor Assays

The pregnane X receptor (PXR) mediates the induction of enzymes involved in steroid metabolism and xenobiotic detoxification. The receptor is expressed in liver and intestinal tissues and is activated by a wide range of compounds. The ability of a diverse range of dietary compounds to activate PXR-mediated transcription was assayed in HuH7 cells following transient transfection with human PXR (hPXR). The compounds investigated included phytochemicals such as lignans and phytoestrogens, organochlorine dietary contaminants such as polychlorinated biphenyls (PCBs) and triclosan and selected steroid, drug and herbal compounds. The hPXR activation at the top concentrations tested (10 microM) relative to the positive control 10 microM rifampicin ranged from 1.3% (trans-resveratrol) to 152% (ICI 182780). Hydroxylated compounds were marginally more potent than the parent compounds (tamoxifen activation was 74.6% whereas 4 hydroxytamoxifen activation was 84.2%) or significantly greater (vitamin D3 activation was 1.6%, while hydroxylated vitamin D3 activation was 55.6%). Enterolactone, the metabolite of common dietary lignans, was a medium activator of PXR (35.6%), compared to the lower activation of a parent lignan, secoisolariciresinol (20%). Two non-hydroxylated PCB congeners (PCB 118 and 153), which present a larger fraction of the PCB contamination of fatty foods, activated hPXR by 26.6% and 17%, respectively. The pesticide trans-nonachlor activation was 53.8%, while the widely used bacteriocide triclosan was a medium activator of hPXR at 46.2%. The responsiveness of PXR to activation by lignan metabolites suggests that dietary intake of these compounds may affect the metabolism of drugs that are CYP3A substrates. Additionally, the evidence that organochlorine chemicals, particularly the ubiquitous triclosan, activate hPXR suggests that these environmental chemicals may, in part, exhibit their endocrine disruptor activities by altering PXR-regulated steroid hormone metabolism with potential adverse health effects in exposed individuals.

Topics: Alkaline Phosphatase; Anti-Bacterial Agents; Carcinoma, Hepatocellular; Cell Line, Tumor; Cytochrome P-450 CYP3A; Cytochrome P-450 Enzyme Inhibitors; Cytochrome P-450 Enzyme System; Enzyme Inhibitors; Humans; Hydrocarbons, Chlorinated; Kinetics; Lignans; Liver Neoplasms; Phytoestrogens; Pregnane X Receptor; Quantitative Structure-Activity Relationship; Receptors, Cytoplasmic and Nuclear; Receptors, Steroid; Retinoid X Receptors; Rifampin; Transfection

To investigate the effect of schisandrin B (Sch B) on proliferation and apoptosis of human hepatoma SMMC-7721 cells in vitro and regulation of Hsp70 and Caspases-3, 7, 9 expression by Sch B.. Human hepatoma cell line SMMC-7721 was cultured and treated with Sch B at various concentrations. Growth suppression was detected with MTT colorimetric assay. Cell apoptosis was confirmed by DNA ladder detection and flow cytometric analysis. The expression of Hsp70, Caspases-3, 7, 9 were analyzed by Western blot analysis.. Sch B inhibited the growth of hepatoma SMMC-7721 cells in a dose-dependent manner, leading to a 50% decrease in cell number (LC50) value of 23.50 mg/L. Treatment with Sch B resulted in degradation of chromosomal DNA into small internucleosomal fragments, evidenced by the formation of a 180-200 bp DNA ladder on agarose gels. FCM analysis showed the peak areas of subdiploid at the increased concentration of Sch B. The results of Western bolt analysis showed that Hsp70 was down-regulated and Caspase-3 was up-regulated, while the activity of Caspases-7, -9 had no significant change.. Sch B is able to inhibit the proliferation of human hepatoma SMMC-7721 cells and induce apoptosis, which goes through Caspase-3-dependent and Caspase-9-independent pathway accompanied with the down-regulation of Hsp70 protein expression at an early event.

Topics: Apoptosis; Blotting, Western; Carcinoma, Hepatocellular; Caspases; Cell Differentiation; Cell Proliferation; Cyclooctanes; Down-Regulation; Flow Cytometry; HSP70 Heat-Shock Proteins; Humans; Lignans; Liver Neoplasms; Polycyclic Compounds; Tumor Cells, Cultured; Up-Regulation

Magnolol, a hydroxylated biphenyl compound isolated from the Chinese herb Hou p'u of Magnolia officinalis, has been reported to have anti-cancer activity. In the present study, magnolol at very low concentrations of 3-10 microM inhibited DNA synthesis and decreased cell number in cultured human cancer cells (COLO-205 and Hep-G2) in a dose-dependent manner, but not in human untransformed cells such as keratinocytes, fibroblasts, and human umbilical vein endothelial cells (HUVEC). Magnolol was not cytotoxic at these concentrations and this indicates that it may have an inhibitory effect on cell proliferation in the subcultured cancer cell lines. [(3)H] thymidine incorporation and flow cytometry analyses revealed that magnolol treatment decreased DNA synthesis and arrested the cells at the G0/G1 phase of the cell cycle. Moreover, the magnolol-induced cell cycle arrest occurred when the cyclin-CDK system was inhibited, just as p21 protein expression was augmented. When magnolol concentration was increased to 100 microM, apoptosis was observed in COLO-205 and Hep-G2 cells, but not in cultured human fibroblasts and HUVEC. COLO-205 cells implanted subcutaneously in nude mice formed solid tumors; subsequent daily i.p.-injections of magnolol led to profound regression of these tumors of up to 85%. In these tumors, an increase in the expression of p21 protein level and the occurrence of apoptosis were observed. These findings demonstrate for the first time that magnolol can inhibit the proliferation of tumor cells in vitro and in vivo.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Biphenyl Compounds; Calcium; Cell Cycle; Cell Cycle Proteins; Cell Division; Cell Nucleus; Cells, Cultured; Colonic Neoplasms; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; DNA; DNA Fragmentation; Humans; Kinetics; Lignans; Liver Neoplasms; Thymidine; Tumor Cells, Cultured

Magnolol has been reported to have anticancer activity. In this study we found that treatment with 100 microm magnolol induced apoptosis in cultured human hepatoma (Hep G2) and colon cancer (COLO 205) cell lines but not in human untransformed gingival fibroblasts and human umbilical vein endothelial cells. Our investigation of apoptosis in Hep G2 cells showed a sequence of associated intracellular events that included (a) increased cytosolic free Ca(2+); (b) increased translocation of cytochrome c (Cyto c) from mitochondria to cytosol; (c) activation of caspase 3, caspase 8, and caspase 9; and (d) downregulation of bcl-2 protein. Pretreatment of the cells with the phospholipase C inhibitor 1-[6-[[(17 beta)-3-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1 H-pyrrole-2,5-dione (U73122) or the intracellular chelator of Ca(2+) 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester (BAPTA/AM) inhibited the subsequent magnolol augmentation of [Ca(2+)](i) and also the activation of caspase-8 and caspase-9, so that the occurrence of apoptosis in those cells was greatly reduced. Pretreatment of the cells with ZB4 (which disrupts the Fas response mechanism) also decreased the subsequent magnolol-induced caspase-8 activation and reduced the occurrence of apoptosis. We interpreted these findings to indicate that the above-listed sequence of intracellular events led to the apoptosis seen in Hep G2 cells and that [Ca(2+)](i), Cyto c, and Fas function as intracellular signals to coordinate those events.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Biphenyl Compounds; Calcium; Caspases; Colonic Neoplasms; Cytochrome c Group; Endothelium, Vascular; fas Receptor; Fibroblasts; Humans; Lignans; Liver Neoplasms; Signal Transduction; Tumor Cells, Cultured

The modifying effects of the naturally occurring antioxidants n-tritriacontane-16,18-dione (TTAD), curcumin, dihydroguaiaretic acid (DHGA), chlorophyllin, tannic acid and phytic acid on the initiation stage in a rat multi-organ carcinogenesis model were examined in male F344 rats. Animals were initiated with two i.p. injections of 2,2'-dihydroxy-di-n-propylnitrosamine (DHPN), followed by two i.g. administrations of N-ethyl-N-hydroxyethylnitrosamine (EHEN), and then three s.c. injections of 3,2'-methyl-4-aminobiphenyl (DMAB) during the first 3 weeks. Starting 1 day before the first carcinogen application, groups of rats received diet containing one of the antioxidants (0.2% TTAD, the others at 1% each) until 1 week after the last carcinogen exposure. Surviving animals were killed and complete autopsies were performed at the end of week 36. Histological examination revealed no inhibitory effects in terms of the multiplicities and/or incidences of neoplastic lesions in any of the organs examined, other than a significant increase in seminal vesicle atypical hyperplasia observed in rats treated with tannic acid. Thus, the antioxidants, with the exception of tannic acid, did not show any modifying effects on the initiation stage in the present multi-organ carcinogenesis model and at the present dose levels applied.

Topics: Aminobiphenyl Compounds; Animals; Antimutagenic Agents; Antineoplastic Agents; Antioxidants; Carcinogens; Chlorophyllides; Curcumin; Diethylnitrosamine; Guaiacol; Hydrolyzable Tannins; Lignans; Liver Neoplasms; Lung Neoplasms; Male; Neoplasms, Experimental; Nitrosamines; Paraffin; Phytic Acid; Precancerous Conditions; Rats; Rats, Inbred F344

The effects of gomisin A, a lignan compound of Schizandra fruits, on hepatocarcinogenesis induced by 3'-methyl-4-dimethylaminoazobenzene (3'-MeDAB) in rats were investigated. Gomisin A inhibited both increases of the number and size of glutathione S-transferase placental form (GST-P)-positive foci, a marker enzyme of preneoplasm, and the population of diploid nuclei, as a proliferative state of hepatocytes, in the liver from rats simultaneously treated with 3'-MeDAB. Gomisin A increased GST activity in the liver, by raising the level of GST 1 and 2 isozymes. 3'-MeDAB increased GST activity and GST-P expression. This high level of GST-P induced by 3'-MeDAB was suppressed by additional treatment with gomisin A. In an experiment on simultaneous treatment, gomisin A increased the biliary excretion of 3'-MeDAB-related aminoazo dyes and decreased the content in the liver of rats fed with 0.06%-3'-MeDAB containing diet. In an experiment on pretreatment with 3'-MeDAB, even though no aminoazo dye was detectable in the liver or bile 2-weeks after cessation of 3'-MeDAB-feeding, gomisin A showed a tendency to reduce the preneoplastic changes of increases in GST-P positive foci and diploid nuclei in the liver. These results suggest that gomisin A inhibits the hepatocarcinogenesis induced by 3'-MeDAB by enhancing the excretion of the carcinogen from the liver and by reversing the normal cytokinesis.

Topics: Animals; Cell Division; Cell Nucleus; Cyclooctanes; Diet; Dioxoles; Drugs, Chinese Herbal; Electrophoresis, Polyacrylamide Gel; Flow Cytometry; Glutathione Transferase; Immunoblotting; Immunohistochemistry; Isoenzymes; Lignans; Liver; Liver Neoplasms; Male; Methyldimethylaminoazobenzene; Ploidies; Protein Binding; Rats

Thirty postmenopausal women (11 omnivores, 10 vegetarians and 9 apparently healthy women with surgically removed breast cancer) were investigated with regard to the association of their urinary excretion of estrogens, lignans and isoflavonoids (all diphenols) with plasma sex hormone binding globulin (SHBG). A statistically significant positive correlation between urinary total diphenol excretion and plasma SHBG was found which remained statistically significant after elimination of the confounding effect of body mass determined by body mass index (BMI). Furthermore we found a statistically significant negative correlation between plasma SHBG and urinary excretion of 16 alpha-hydroxyestrone and estriol which also remained significant after eliminating the effect of BMI. Furthermore we observed that enterolactone (Enl) stimulates the synthesis of SHBG by HepG2 liver cancer cells in culture acting synergistically with estradiol and at physiological concentrations. Enl was rapidly conjugated by the liver cells, mainly to its monosulfate. Several lignans and the isoflavonoids daidzein and equol were found to compete with estradiol for binding to the rat uterine type II estrogen binding site (the s.c. bioflavonoid receptor). It is suggested that lignans and isoflavonoids may affect uptake and metabolism of sex hormones by participating in the regulation of plasma SHBG levels and in this way influence their biological activity and that they may inhibit cancer cell growth like some flavonoids by competing with estradiol for the type II estrogen binding sites.

Topics: Animals; Breast Neoplasms; Carcinoma, Hepatocellular; Cell Line; Cell Nucleus; Diet; Diet, Vegetarian; Estradiol; Estrogens; Female; Humans; Isoflavones; Lignans; Lignin; Liver Neoplasms; Menopause; Ovariectomy; Rats; Receptors, Estrogen; Sex Hormone-Binding Globulin; Uterus