Effects ofGinkgo bilobaextract on cell proliferation and cytotoxicity in human hepatocellular carcinoma cells

Abstract

To study the effect of Ginkgo biloba extract (EGb 761) containing 22-27% flavonoids (ginkgo-flavone glycosides) and 5-7% terpenoids (ginkgolides and bilobalides) on cell proliferation and cytotoxicity in human hepatocellular carcinoma (HCC) cells. Human HCC cell lines (HepG2 and Hep3B) were incubated with various concentrations (0-1 000 mg/L) of EGb 761 solution. After 24 h incubation, cell proliferation and cytotoxicity were determined by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and lactate dehydrogenase (LDH) release, respectively. After 48 h incubation, the expression of proliferating cell nuclear antigen (PCNA) and p53 protein was measured by Western blotting. The results showed that EGb 761 (50-1 000 mg/L) significantly suppressed cell proliferation and increased LDH release (P<0.05) in HepG2 and Hep3B cells compared with the control group. The cell proliferation of HepG2 and Hep3B cells treated with EGb 761 (1 000 mg/L) was 45% and 39% of the control group (P<0.05), respectively. LDH release of HepG2 cells without and with EGb 761 (1 000 mg/L) treatment was 6.7% and 37.7%, respectively, and that of Hep3B cells without and with EGb 761 (1 000 mg/L) treatment was 7.2% and 40.3%, respectively. The expression of PCNA and p53 protein in HepG2 cells treated with EGb 761 (1 000 mg/L) was 85% and 174% of the control group, respectively. Ginkgo biloba extract significantly can suppress proliferation and increase cytotoxicity in HepG2 and Hep3B cells. Additionally, Ginkgo biloba extract can decrease PCNA and increase p53 expression in HepG2 cells.