Inhibitory effect of ginkgols on SMMC-7721 liver cancer cells in vitro and liver cancer H22-bearing mice in vivo

Objective: To study the inhibitory effects of ginkgols on SMMC-7721 liver cancer cells in vitro,and on tumor growth of H22-bearing mice in vivo.Methods: The inhibitory effect of ginkgol on SMMC-7721 cells was evaluated by the survival rate of SMMC-7721 cells using MTT assay;then half maximal inhibitory concentration(IC50) was calculated.The solid tumor model of liver cancer H22-bearing mice was established,and all mice were randomly divided into model control group,cyclophosphamide(CTX) group,four ginkgol groups(20,40,80,160 mg/kg),eight in each group.All mice in the groups received intraperitoneal injeciton of normal saline(0.2 mL each),CTX(2 mg/kg body weight),ginkgol 20,40,80,160 mg/kg,respectively,for 7-d.At 24 hours after the final injection,blood sample was collected by eye bleed;samples of tumor tissues,spleen and thymus were harvested after mice were killed.The inhibition rate of the anti-tumor,spleen index and thymus index were calculated.The levels of lymphocytes in peripheral blood were measured.Results: MTT assay showed that ginkgols inhibited the proliferation of SMMC-7721 cells with half maximal inhibitory concentration(IC50) values of(15.33±1.19),(12.20±1.08) and(10.88±1.03) mg/L for 24,48,and 72 hours,respectively.The inhibition rate of 20,40,80 and 160 mg/kg group were 8.96%、39.81%、48.51% and 28.36%,respectively.Except for 40 mg/kg group,there were significant differences in inhibition rate between the other ginkgols groups and model control group(both P0.05).The levels of lymphocytes in ginkgols groups from peripheral blood were significantly increased,compared with CTX group(P0.01).Conclusion: Ginkgols showed markedly inhibitory effects on cell proliferation of human hepatic carcinoma cell lines SMMC-7721 in vitro,and on tumor growth of H22-bearing mice,which could be associated with the regulation of immune function.