stilbenes and 3-3--4-4--5-5--hexahydroxystilbene

HIV resistance to current anti-HIV drugs and drug toxicity have created a need for new anti-HIV agents. We have examined and characterized a synthetic resveratrol analog, termed 3,3',4,4',5,5'-hexahydroxy-trans-stilbene (M8), for potential anti-HIV activity. Here, we demonstrate that M8 possesses potent anti-HIV activity against several HIV variants with EC50 values in the low μM range. M8 was shown to act at a very early step of HIV entry prior to fusion to host cells. These results demonstrate that this novel resveratrol derivative possesses potent anti-HIV-1 activity and may have a mechanism of action that is different from current anti-HIV-1 drugs including entry inhibitors. Further structure-guided design might lead to the development of newer improved resveratrol derivatives that could have value either in therapy or as microbicides to prevent the sexual transmission of HIV-1.

Topics: Antiviral Agents; HIV-1; Humans; Microbial Sensitivity Tests; Pyrogallol; Stilbenes

The expression of P450 enzymes and antioxidative enzymes in tumour tissue can have a major impact on the responsiveness of tumours to cancer chemotherapeutic drugs, therefore such information may be very precious when experiments are designed. The compressive information, concerning the expression of drug metabolism enzymes or antioxidative enzymes is still lacking, therefore in this study the expression of CYP1A1, CYP1B1 and mitochondrial superoxide dismutase MnSOD (both mRNA and protein) in a panel of eight commonly used cancer cell lines, representing four tumour tissues was assayed. In the study two ovarian cancer cell lines A2780 and SKOV-3, two colorectal cancer LOVO and DLD-1, two breast cancer derived MCF-7 and MDA-MB-231 and two cervical cancer cell lines HeLa and C33A were employed. The relatively high expression of all assayed enzymes was shown in MDA-MB-231 breast cancer cells, lack of cancer cell specific CYP1B1 protein was discovered in LOVO colorectal cells. In order to test possible correlation between expression of CYP1A1, CYP1B1 and MnSOD and modulators of their activity, cytotoxicity of resveratrol and its promising hydroxylated analogue 3,3',4,4',5,5'-trans-hexahydroxystilbene against cell lines used in experiment was assayed. The relatively high correlation was found between IC50 values calculated for 3,3',4,4',5,5'-trans-hexahydroxystilbene and expression of MnSOD (r = 0.6562).

Topics: Aryl Hydrocarbon Hydroxylases; Cell Death; Cell Line, Tumor; Cytochrome P-450 CYP1A1; Cytochrome P-450 CYP1B1; Gene Expression Regulation, Neoplastic; Humans; Inhibitory Concentration 50; Pyrogallol; Resveratrol; Stilbenes; Superoxide Dismutase

3,3',4,4',5,5'-Hexahydroxy-trans-stilbene (M8) is a synthetic resveratrol derivative, advertised as a candidate drug highly effective against numerous malignancies. Because multiple tumors prone to M8 frequently metastasize into the peritoneal cavity, this study was aimed at establishing the effect of M8 on the growth and senescence of human peritoneal mesothelial cells (HPMCs), the largest cell population within the peritoneum, actively involved in the intraperitoneal spread of cancer. The study showed that M8, used at the highest non-toxic dose of 10 μM, impairs proliferation and accelerates senescence in cultured HPMCs via an oxidative stress-dependent mechanism. At the same time, soluble factors released to the environment by HPMCs that senesced prematurely in response to M8 promoted growth of colorectal and pancreatic carcinomas in vitro. These findings indicate that M8 may indirectly-through the modification of normal (mesothelial) cells phenotype-facilitate an expansion of cancer cells, which challenges the postulated value of this stilbene in chemotherapy.

Topics: Carcinogenesis; Cell Line, Tumor; Cellular Senescence; Epithelium; Gastrointestinal Neoplasms; Humans; Oxidative Stress; Peritoneal Neoplasms; Peritoneum; Pyrogallol; Resveratrol; Stilbenes

Stilbenes comprise a group of polyphenolic compounds, which exert inhibitory effects on various malignancies. The aim of this study was to evaluate the antitumor effects of a previously unreported stilbene derivative-3,3',4,4',5,5'-hexahydroxystilbene, termed M8-on human melanoma cells. Cell-cycle analysis of the metastatic melanoma cell line M24met showed that M8 treatment induces G(2)/M arrest accompanied with a dose- and time-dependent upregulation of p21 and downregulation of CDK-2 and leads to apoptosis. M8 induces the expression of phosphorylated p53, proteins involved in the mismatch repair machinery (MSH6, MSH2, and MLH1) and a robust tail moment in a comet assay. In addition, M8 inhibited cell migration in Matrigel assays. Shotgun proteomics and western analysis showed the regulation among others of paxillin, integrin-linked protein kinase, p21-activated kinase, and ROCK-1 indicating that M8 inhibits mesenchymal and amoeboid cell migration. These in vitro data were confirmed in vivo in a metastatic human melanoma severe combined immunodeficient (SCID) mouse model. We showed that M8 significantly impairs tumor growth. M8 also interfered with the metastatic process, as M8 treatment prevented the metastatic spread of melanoma cells to distant lymph nodes in vivo. In summary, M8 exerts strong antitumor effects with the potential to become a new drug for the treatment of metastatic melanoma.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cyclin-Dependent Kinase 2; Cyclin-Dependent Kinase Inhibitor p21; Disease Models, Animal; Disease Progression; DNA Damage; Dose-Response Relationship, Drug; Female; Humans; Melanoma; Mice; Mice, SCID; Paxillin; Pyrogallol; Skin Neoplasms; Stilbenes; Tumor Suppressor Protein p53; Xenograft Model Antitumor Assays

The phytochemical resveratrol, which is found in grapes and red wine, has been reported to have a variety of biological properties. It was shown in our previous research that introduction of additional hydroxyl groups into the stilbene structure increases the biological activity of resveratrol. In this study, the activity of 3,3',4,4',5,5'-hexahydroxystilbene (M8) was investigated in ZR-75-1, MDA-MB-231 and T47D human breast cancer cells. For evaluation of cytotoxic activity of M8, clonogenic and cell proliferation assays were used. The IC50 values obtained in the clonogenic assay were 0.846 microM for T47D, 8.53 microM for ZR-75-1 cells and 25.5 microM for MDA-MB-231, while IC50 values obtained in the cell proliferation assay were significantly higher: 90.1 microM, 98.4 microM, 127.8 microM for T47D, ZR-75-1 and MDA-MB-231 cells, respectively. Compound M8 caused the activation of caspase-8 in MDA-MB-231 cells (marker of extrinsic apoptotic pathway), while activities of caspase-9 (marker of intrinsic apoptotic pathway) and caspase-3 were increased in all 3 tested cell lines. Activation of caspase-9 and caspase-3 was connected with loss of mitochondrial potential and increase of p53, which could have an impact on downregulation of mitochondrial superoxide dismutase (MnSOD) seen in our experiments. MnSOD is a key enzyme providing antioxidative defense in mitochondria - the cellular center of reactive oxygen species' generation. Downregulation of MnSOD can therefore cause a significant decrease of antioxidant defense in cancer cells. An increase of oxidative stress conditions was suggested by loss of reduced glutathione in tested cells. Since cancer cells are usually under permanent oxidative stress, additional increased ROS generation as a result of the interaction of M8 with the mitochondrial respiratory chain and a decrease in oxidative defense can therefore be a promising method for selective elimination of cancer cells.

Topics: Antineoplastic Agents; Breast Neoplasms; Caspases; Cell Death; Cell Line, Tumor; Cell Proliferation; Cell Survival; Clone Cells; Dose-Response Relationship, Drug; Down-Regulation; Enzyme Activation; Female; Humans; Membrane Potential, Mitochondrial; Mitochondria; Pyrogallol; Stilbenes; Superoxide Dismutase; Tumor Suppressor Protein p53

Resveratrol (3,4',5-trihydroxy-trans-stilbene; RV), an ingredient of wine, exhibits a broad spectrum of antiproliferative effects against human cancer cells. In order to enhance these effects, we modified the molecule by introducing additional methoxyl and hydroxyl groups. The resulting novel RV analogs, M5 (3,4',5-trimethoxy-trans-stilbene), M5A (3,3',4,5'-tetramethoxy-trans-stilbene) and M8 (3,3',4,4',5,5'-hexahydroxy-trans-stilbene) were investigated in HT29 human colon cancer cells. Cytotoxicity was evaluated by clonogenic assays and the induction of apoptosis was determined using a specific Hoechst/propidium iodide double staining method. Cell cycle distribution was evaluated by FACS. The influence of M8 on the concentration of deoxyribonucleoside triphosphates (dNTPs), the products of ribonucleotide reductase (RR), was determined by high-performance liquid chromatography. M5 and M5A caused a dose-dependent induction of apoptosis and led to remarkable changes of the cell cycle distribution. After treatment with M5, growth arrest occurred mainly in the G2-M phase, whereas incubation with M5A resulted in arrest in the G0-G1 phase of the cell cycle. Incubation of HT29 cells with M8 produced a significant imbalance of intracellular dNTP pools, being synonymous with the inhibition of RR activity. The dATP pools were abolished, whereas the dCTP and dTTP pools increased. Due to these promising results, the investigated RV analogs deserve further preclinical and in vivo testing.

Topics: Anisoles; Antineoplastic Agents; Apoptosis; Cell Cycle; Chromatography, High Pressure Liquid; Deoxyribonucleotides; HT29 Cells; Humans; Molecular Structure; Pyrogallol; Resveratrol; Ribonucleotide Reductases; Stilbenes; Tumor Stem Cell Assay

Resveratrol (3,4',5,-trihydroxystilbene, RV), an ingredient of wine, is an inhibitor of the proliferation-linked enzyme ribonucleotide reductase (RR) and shows a broad spectrum of cytotoxic effects against human cancer cells. In order to enhance these effects, we introduced additional hydroxyl moieties into the molecule. In the present study, the activity of a novel RV analog, 3,3',4,4',5,5'-hexahydroxystilbene (M8), was investigated in HL-60 human promyelocytic leukemia cells.. Cytotoxicity of M8 alone or in combination with Ara-C was assessed employing growth inhibition assays. Effects of M8 on nucleoside triphosphates (NTPs) and deoxynucleoside triphosphates (dNTPs) were examined by HPLC. The apoptotic potential of M8 and RV was compared using a specific double-staining method and inhibition of TNF-alpha-induced activation of NF-kappaB was studied. Cell-cycle distribution was analyzed by FACS.. Addition of ascorbic acid decreased the IC(50) value of M8 from 6.25 microM to 2 microM. M8 depleted dATP and dTTP pools to 41% and 21% of control values, whereas dCTP pools increased to 199% of untreated controls. In addition, TTP, ATP, CTP, and GTP concentrations were decreased while UTP concentrations increased. M8 induced apoptosis at concentrations significantly lower than RV and could remarkably inhibit the activation of NF-kappaB. M8 arrested cells in the S phase of the cell cycle while depleting cells in the G2-M phase and exhibited synergistic combination effects when applied simultaneously with Ara-C.. Due to these promising results, this novel polyhydroxylated stilbene derivative might become an additional option for the treatment of leukemia and therefore deserves further preclinical and in vivo testing.

Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Cell Cycle; Cytarabine; Deoxyribonucleotides; Drug Evaluation, Preclinical; Enzyme Inhibitors; HL-60 Cells; Humans; Leukemia, Promyelocytic, Acute; NF-kappa B; Pyrogallol; Resveratrol; Ribonucleotide Reductases; Ribonucleotides; Stilbenes; Tumor Necrosis Factor-alpha; Wine

Resveratrol (3,4',5-trihydroxystilbene, RV) exerts remarkable cytostatic and cytotoxic effects against a multitude of human cancer cell lines. Since the introduction of additional hydroxyl groups was supposed to increase the biological activity of RV, we have synthesized a number of polyhydroxylated stilbene analogues as potential antitumor agents. In this study, the activity of 3,3',4,4',5,5'-hexahydroxystilbene (M8) was investigated in HL-60 human promyelocytic leukemia cells. Employing a growth inhibition assay, incubation with M8 and RV resulted in IC50 values of 6.25 and 12 microM, respectively. Using a specific Hoechst/propidium iodide double staining method, we found that M8 was able to induce apoptosis in concentrations significantly lower than those of RV. In addition, M8 arrested cells in the S phase and totally depleted cells in the G2-M phase of the cell cycle (143% and 0% of control after treatment with 12.5 microM M8, respectively). We therefore believe that this promising agent deserves further preclinical and in vivo testing.

Topics: Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Bisbenzimidazole; Cell Cycle; Cytarabine; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Drug Synergism; Fluorescent Dyes; HL-60 Cells; Humans; Inhibitory Concentration 50; Leukemia, Promyelocytic, Acute; Propidium; Pyrogallol; Stilbenes