Abstract: OBJECTIVE:To investigate the inhibitory effect of Yiguanjian decoction(YD) on DNA damage in Concanavalin A(Con A)-induced liver injury mice model and to explain the possible mechanism.METHODS:Totally 120 male BALB/c mice were randomly divided into 6 groups,20 mice each:normal group,model group,Bifendate group,YD low dose group,YD middle dose group and YD high dose group.Except normal group,liver injury model induced by Con A was established.While modeling,each mouse in YD group was given YD(0.4 m L/20 g per day) by intragastric administration(0.13 g YD for YD low dose group;0.26 g for YD middle dose group;0.52 g for YD high dose group).Bifendate group was given Bifendate(0.2 gnd model·kg-1 grou·d-1) by gavage.Normal group ap were fed with same volume of physiological saline daily.After 8 weeks,the serum alanine transaminase(ALT)and aspartate transaminase(AST) were tested.The hematoxylin-eosin staining was used to evaluate the grade of liver inflammation and liver fibrosis stage.Hepatocellular DNA damage was detected by single cell gel electrophoresis technology.The protein expression of tumor necrosis factor-α(TNF-α),Bax and Mut T Homolog 1(MTH1) was detected by western blotting and enzyme linked immunosorbent assay.Bax m RNA and MTH1 m RNA were detected by Real-time Polymerase Chain Reaction(PCR).RESULTS:YD can improve the degree of liver inflammation and fibrosis in the liver of chronic hepatitis mice,the dose effect relationship is remarkable(P < 0.05).YD can reduce liver cell DNA damage.The difference between YD middle dose group and model group was statistically significant(P < 0.05).YD middle dose group had decreased the protein expression of TNF-α in the mice liver of immunological liver injury(P < 0.05).YD can increase the protein expression of Bax(P < 0.05).Compared with normal group,the protein expression of MTH1 was decreased(P < 0.05),but there was no statistical significance between YD group and model group(P >0.05).YD can increase the m RNA expression of Bax and MTH1(both P < 0.05).CONCLUSION:YD can effectively inhibit the DNA damage in immunological liver injury mice,the mechanism may be that it can decrease the TNF-αand increase the Bax and MTH1 expression.

Key words: Drug-induced liver injury, Liver kidney Yin deficiency, DNA damage, Concanavalin A, Yiguanjian decoction