Mechanism of flavonoids from Galium verum on cell proliferation and apoptosis of HepG2 / 中草药

ABSTRACT

Objective: To investigate the inhibition of cell proliferation and induction of apoptosis of flavonoids [diosmetin-7-O-β-D-xylopyranosyl-(1 → 6)-β-D-glucopyranoside, DXG)] from Gallium verum on liver cancer cell HepG2 and to study its mechanisms. Methods: Cell growth was detected with Trypan blue staining. The proliferation inhibition rates of DXG on HepG2 were measured by MTT assay. The morphology changes of apoptotic cell were obserbed by AO-EB double staining. Agarose gel electrophoresis was used to detect the DNA fragmentation. The expression of apoptosis-related genes bax and bcl-2 was examined by RT-PCR. Results: DXG (50, 100, and 200 μg/mL) could significantly inhibit the proliferation of HepG2 cells by Trypan blue staining and MTT assay compared with the control group (P < 0.05). AO-EB double staining showed that DXG could induce the apoptosis and morphological change of HepG2 cells and the ratios of apoptosis were obviously high when the concentration of DXG increased. The laddering pattern was clearly presented in the cells treated with 100 and 200 μg/mL DXG for 48 h. RT-PCR showed that DXG could up-regulate the mRNA level of bax and down-regulate the mRNA levels of bcl-2 in HepG2 cells. Conclusion: DXG could obviously inhibit the proliferation and induce the apoptosis in HepG2 cells. The mechanism is related to the modulation of the expression level of bax/bcl-2 mRNA.