salvianolic-acid-B and Liver-Neoplasms

Topics: Animals; Apoptosis; Benzofurans; Cell Movement; Cell Proliferation; Gene Expression Regulation; Hep G2 Cells; Humans; Liver Neoplasms; Mice; Mutation; Phosphorylation; Random Allocation; Smad3 Protein; Up-Regulation

Chinese medicines are emerging as an attractive new generation of anticancer drugs. Here, we explored the impact of salvianolic acid B (Sal B), the major water-soluble compounds of Danshen, on apoptosis and autophagy of human hepatocellular carcinoma cells (HCC). We also investigated the related molecular mechanisms. We found that Sal B exhibits potent ability to inhibit HCC cells viability in a concentration-dependent manner, and to induce apoptosis via the mitochondrial apoptosis pathway. Additionally, Sal B could also induce autophagy. Furthermore, pretreatment with the autophagy inhibitor chloroquine or 3-methyladenine showed the potential in attenuating the apoptosis rate induced by Sal B. Mechanistically, Sal B treatment inhibited the AKT/mTOR signaling cascade in vitro. Overexpression of AKT abolished the effects of Sal B on HCC cells, suggesting a critical role of the AKT/mTOR signaling pathway in Sal B-induced biological effects. Our results indicated that the mitochondrial pathway was involved in Sal B-induced apoptosis of HCC cells. Moreover, the AKT/mTOR signaling pathway was involved in Sal B-induced autophagy, which promoted apoptosis. This study may provide a promising strategy for using Sal B as a chemotherapeutic agent for patients with HCC.

Topics: Adenine; Antineoplastic Agents; Apoptosis; Autophagy; Beclin-1; Benzofurans; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Proliferation; Chloroquine; Drugs, Chinese Herbal; Humans; Liver Neoplasms; Mitochondria; Proto-Oncogene Proteins c-akt; RNA Interference; RNA, Small Interfering; Salvia miltiorrhiza; Signal Transduction; TOR Serine-Threonine Kinases

Enzymes involved in drug and xenobiotic metabolism have been considered to exist in two groups: phase I and phase II enzymes. Cytochrome P450 isoenzymes (CYPs) are the most important phase I enzymes in the metabolism of xenobiotics. The products of phase I metabolism are then acted upon by phase II enzymes, including glutathione S-transferases (GSTs). Herbs that inhibit CYPs such as CYP3A4 or that induce GSTs may have the potential to protect against chemical carcinogenesis since the mutagenic effects of carcinogens are often mediated through an excess of CYP-generated reactive intermediates. This study was designed to investigate the effects of salvianolic acid B (Sal B), a pure compound extracted from Radix Salviae Miltiorrhizae, a Chinese herb, on cell proliferation and CYP1A2 and CYP3A4 mRNA expression in the presence or absence of rifampicin, a potent inducer of CYPs and GST protein expression in HepG2 cells.. HepG2 cells were incubated with different concentrations of Sal B. Cell proliferation was determined by SYTOX-Green nucleic acid staining. CYP3A4 and CYP1A2 mRNA expression was assayed by real-time PCR. GST protein expression was analyzed by Western blotting.. Low concentrations of Sal B (0-20 μmol/L) had no significant effects on cell proliferation, while higher concentrations (100-250 μmol/L) significantly inhibited proliferation in a concentration-dependent manner. Ten μmol/L Sal B, but not 1 μmol/L, down-regulated CYP3A4 and CYP1A2 mRNA expression after 24 hours of incubation, whereas both 1 and 10 μmol/L Sal B down-regulated CYP3A4 mRNA expression after 96 hours of incubation; moreover, 1 and 10 μmol/L Sal B inhibited CYP3A4 mRNA expression induced by rifampicin. Both 1 μmol/L and 10 μmol/L Sal B increased GST expression.. Sal B inhibits CYP3A4 and CYP1A2 mRNA expression and induces GST expression in HepG2 cells.

Topics: Benzofurans; Blotting, Western; Cell Proliferation; Cytochrome P-450 CYP1A2; Cytochrome P-450 CYP3A; Dose-Response Relationship, Drug; Enzyme Induction; Enzyme Repression; Gene Expression Regulation, Neoplastic; Glutathione Transferase; Hep G2 Cells; Humans; Liver Neoplasms; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Rifampin; RNA, Messenger; Time Factors