Protective effects of the bioactive natural product N-trans-Caffeoyldopamine on hepatotoxicity induced by isoniazid and rifampicin.

In our searching for novel antioxidants from natural sources, N-trans-Caffeoyldopamine which was from natural product was found to be a potential compound for its remarkable antioxidant activity. Isoniazid (INH) and Rifampicin (RFP) is widely used for the treatment of Tuberculosis (TB) as the first line drugs, have been known to be potentially hepatotoxic and may lead to drug-induced liver injury. Oxidative stress has been regarded as the major mechanism of the hepatotoxicity. Therefore, in this study, the possible protective effects of N-trans-Caffeoyldopamine was investigated in the hepatotoxicity caused by INH and RFP in rats. Results showed that serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and hepatic malondialdehyde (MDA) content were reduced dramatically, and hepatic superoxide dismutase (SOD) activity and glutathione (GSH) content were restored remarkably by N-trans-Caffeoyldopamine co-administration, as compared to the INH-RFP treated rats (p<0.01). Moreover, the histopathological damage of liver and the number of apoptotic hepatocytes were also significantly ameliorated by the treatment. It is therefore suggested that N-trans-Caffeoyldopamine can provide a definite protective effect against acute hepatic injury caused by INH and RFP in rats, which may mainly be associated with its antioxidative effect. Mechanisms studies indicated that it inhibited the lipid peroxidation through the cytochrome P450 2E1 (CYP2E1) downregulation.