Objective: To investigate the effects of Ginkgo biloba extract(EGB) on proliferation

apoptosis and Caspase-3 expression in human breast cancer MCF-7 cells. Method: The human breast cancer MCF-7 cells cultivated in vitro were treated with 0

10

20

40

80

160 mg·L-1 of EGB

cultured for 24 h or 48 h. The 3-(4

5-dimethylthiazol-2-yl)-2

5-diphenyl-tetrazolium bromide (MTT) assay was used to measure the cell proliferative effect. The annexin V/PI double staining analysis by flow cytometry was used to evaluate apoptotic rate and the cell cycle. The expression of Caspases-3 protein was detected by enzyme-linked immunosorbent assay (ELISA). Result: EGB could inhibit the proliferation of MCF-7 cells in vitro

and concentration-effect relationship was significant (P<0.01). 50% inhibition concentration(IC50) of MCF-7 was 83.65 mg·L-1. The flow cytometry test indicated that EGB could make MCF-7 cells G0-G1 phase gradually increasing

G2-M period and S phase reduce gradually and with the increase of the concentration

MCF-7 cell apoptosis rate increased significantly (P<0.05 or P<0.01). EGB could enhance MCF-7 cells Caspases-3 protein expression (P<0.05 or P<0.01) and with the concentration dependent. Conclusion: EGB could effectively restrain human breast cancer MCF-7 cells Caspases-3 protein expression

induction MCF-7 cell apoptosis

inhibiting tumor cell proliferation.