Résumé
Objective:To investigate the protective effect of Epigallocatechin-3-gallate (EGCG) on triptolide (TP)-induced immunological liver injuries, and explore the relevant mechanisms of action. Methods: A total of 40 female C57BL/6 mice were randomly divided into four groups:control group,EGCG group,TP group and TP+EGCG group. The ALT levels in serum was examined by Reitman Frankel method. The activity of hepatic MDA,SOD and GSH was examined by spectrophotometry. HE staining was used to observed the changes of the hepatic histopathology. The hepatic IL-17,IL-6 levels was examined by ELISA and the expression of hepatic TLR4 protein was examined by Western blot. Results:The results showed that serum alanine aminotransaminase ( ALT) levels of TP group were obviously elevated (P0. 05). Meanwhile,EGCG could ameliorate hepatic pathological damage. Furthermore,in TP group,the activity of malondialdehyde ( MDA) ,the expression of Toll-like receptor 4 (TLR4) protein and the contentration of hepatic interleukin (IL)-17,IL-6 were higher than normal control group ( P<0. 005 ) . On the contrary, the activity of superoxide dismutase ( SOD ) and restored glutathione ( GSH ) were significantly lower than normal control group ( SOD, P<0. 05;GSH, P<0. 005 ) . In EGCG treatment group, the expression of TLR4 protein and the concentration of MDA,hepatic IL-17 and IL-6 were lower than TP group ( TLR4,P<0. 05;MDA,P<0. 005;IL-17,P<0. 005;IL-6,P<0. 005). On the contrary,SOD and GSH were significantly higher than TP group (SOD,P<0. 05;GSH,P<0. 005). Conclusion:This study suggests that EGCG possesses hepatoprotective effect against TP-induced immunological liver injury through its anti-inflammatory and anti-oxidant actions.