Abstract: Objective To study the correlation of lipid peroxidation,P450 drug-metabolizing enzyme of liver tissue and hepatotoxicity. Methods Fifty-six healthy adult rats were divided randomly into 7 groups: INH(H),RFP(R),PZA(Z),HR,RZ,HRZ,the control group.The rats took different drugs and same foods for 10 days,and then were taken the livers.The livers were cut into slices and watched pathologic changes of hepatic cells under electronic microscope,were homogenized and measured MDA,GSH,SOD,P450. Results MDA and P450 increased,while GSH and SOD decreased in each drug group.In the groups contained RFP,level of P450 increased significantly.The degree of liver damage and the change of index of lipid peroxidation were more severe in the combined antituberculous drug groups than that in the single antituberculous drug groups.The hepatic pathologic damage was related with the degree of lipid peroxidation. Conclusion INH,RFP,PZA all could induce the lipid peroxidation and hepatic damage

Key words: Isoniazid, Rifampicin, Pyrazinamide, Liver damage, Lipid peroxidation, Cytochrome P450, Liver drug enzyme