[Effects of total C-21 steroidal glycosides from Baishouwu on proliferation invasion and apoptosis of human hepatic cancer HepG2 cells].

This study aimed to investigate the inhibitory effect of total C-21 steroidal glycoside (TCSG) from Baishouwu on the proliferation, invasion and apoptosis of human hepatoma HepG2 cells in vitro and the relevant molecular mechanism. The experiment was divded into control group, TCSG groups (25, 60, 150 mg·L⁻¹) and positive control cisplatin group (1.33 mg·L⁻¹). Human hepatocyte L-02 cells and hepatoma HepG2 cells were treated with different concentrations of TCSG. Then, the inhibitory effect of TCSG on the proliferation of HepG2 cells was detected by CCK-8 method. Cell cycle, cell apoptosis and mitochondrial membrane potential were detected by flow cytometry. The apoptotic morphology was observed by Hoechst 33258 staining. Cell migration and invasion abilities were analyzed by Transwell chamber model. The protein expressions of Bcl-2, Bax, caspase 3, cleaved caspase 3 and Cyt C (cytosolchondrial) were detected by Western blot. Compared with the control group, the proliferation of HepG2 cells was significantly inhibited after treatment with different concentrations of TCSG for 48 h in a dose-dependent manner( P <0.01), but no obvious effect was observed on the proliferation of L-02 cells. After treatment with TCSG for 48 h, apoptotic morphology such as nuclear shrinkage, fragmentation and semilunar or circular was observed; migration and invasion abilities of cells were significantly decreased, cell cycle was blocked in the G₀/G₁ phase( P <0.01), mitochondrial membrane potential was remarkably decreased( P <0.01), and so did the ratio of apoptosis( P <0.01).Western blot results showed that the protein expressions of Bax, caspase 3, cleaved caspase 3, and Cyt C were significantly up-regulated( P <0.05, P <0.01), while the Bcl-2 protein was significantly down-regulated( P <0.05, P <0.01). Furthermore, the ratio of Bax/Bcl-2 was increased ( P <0.01). The results suggested that TCSG could inhibit the proliferation and invasion of HepG2 cells, and induce the apoptosis of HepG2 cells. The potential mechanism may be related to the blocking of cell cycle and the regulation of the expressions of apoptosis-related proteins by activating mitochondrial pathway.