Effects of genistein on proliferation and DNA damage of irradiated human liver L-02 cells

Abstract

Objective To investigate the radioprotective effects of genistein(GEN) against radiation-induced DNA damage in human liver cell line L-02.Methods(1)L-02 cells were treated with different concentrations of GEN(1,5,10,and 20 μmol/L) for 24 h,and then irradiated with X-ray at the doses of 6,8,12,16,and 20 Gy.Forty-eight hours after irradiation,MTT method was applied to examine the proliferation of L-02 cells.(2)L-02 cells were treated with different concentrations of GEN(1,5,10,and 20 μmol/L) for 24 h,and then irradiated with X-ray at the doses of 8 Gy(300 cGy/min).Single cell gel electrophoresis was used to determine the DNA damage after radiation.Results(1)After irradiation with 6,8 and 12 Gy of X-ray,the cell proliferation rate of 5 μmol/L GEN-pretreated group was significantly increased compared to radiation alone(R) group(P0.05).But no significant increase was observed in GEN-pretreated groups irradiated with 16 Gy and 20 Gy of X-ray compared with R group.(2)As for the DNA damage,no comet cells were detected in normal control group or all GEN-treated groups without irradiation.After irradiation with 8 Gy of X-ray for 24 h,comet incidences were less than 1% in all GNE-pretreated groups and R group,and comet tail length showed no significant difference between different groups.At 48 h after irradiation,the comet incidence of R group was(24.2±1.2)% and the comet tail length was(283.6±22.3) μm,while both comet incidence and tail length of GEN-pretreated groups were significantly lower than those of R group(P0.05).The comet incidence and tail length of R group were significantly decreased 72 h after irradiation compared with 48 h after irradiation(P0.05),and those in 1 μmol/L and 5 μmol/L GEN-pretreated groups were still significantly lower than those of R group(P0.05),but the comet incidence and tail length of 10 μmol/L and 20 μmol/L GEN-pretreated groups were significantly increased compared to those of R group(P0.05).Conclusion Low concentration of GEN(1 and 5 μmol/L) can effectively protect the human liver cells L-02 against X-ray(8 Gy)-induced DNA damage.