Effects of melatonin on hepatocyte cytochrome P450 2E1 expression in rats with nonalcoholic steatohepatitis

Objective To observe the effects of melatonin on hepatocyte cytochrome P450 2E1(CYP2E1)expression in rats with nonalcoholic steatohepatitis.Methods Fifty male Wistar rats were randomly divided into 5 groups with 10 for each.The melatonin in low does,moderate does,high does group and model group were fed with high fat diet while the normal control group with common diet for 12 weeks.Melatonin(contain≤1% dehydrated alchol)was intraperitoneally injected to the rats in various melatonin groups(2.5 mg/kg,5 mg/kg,and 10 mg/kg,respectively)and equal does of saline(contain 1% dehydrated alcohol)to normal control group and model group once a day.Histopathological changes in liver were observed.The levels of liver tissue homogenates triglyceride(TG),total cholesterol(TC),superoxide dismutase(SOD),malondialdehyde(MDA)and GSH-peroxidase(GSH-Px)were measured by biochemical methods.The expression of CYP2E1 in liver was observed by immunohistochemical method.Results Compared with normal control group,the model group developed middle-serious steatosis,the levels of liver tissue homogenates TC,TG,MDA increased(P0.01)and the expression of CYP2E1 in liver enhanced,liver tissue homogenates SOD and GSH-Px decreased(P0.05).Compared with model group,the levels of TC,TG,MDA in liver tissue homogenates decreased,GSH-Px,SOD increased,pathological changes in liver was improver in melatonin-treated groups.The expression of CYP2E1 in liver of rats treated with high does of MT was inhibited(P0.05).Conclusion Melatonin can inhibit the hepatocyte CYP2E1 expression,improve antioxidase activity and depress lipid peroxidation in rats with noncoholic steatohepatitis.