AIM To evaluate the hepatoprotective effect of lycopene(Ly) on non-alcoholic fatty liver disease(NAFLD) in rat. METHODS A rat model of NAFLD was first established by feeding a high-fat diet for 14 wk. Sixty-five rats were randomly divided into normal group, model group and Ly treatment groups. Alanine aminotransferase(ALT), aspartate aminotransferase(AST), triglycerides(TG), total cholesterol(TC) in serum and low density lipoproteincholesterol(LDL-C), high density lipoprotein-cholesterol(HDL-C), free fatty acid(FFA), malondialdehyde(MDA), superoxide dismutase(SOD), glutathione(GSH) in liver tissue were evaluated, respectively. While the hepatoprotective effect was also confirmed by histopathological analysis, the expression levels of TNF-α and cytochrome P450(CYP) 2E1 in rat liver were determined by immunohistochemistry analysis.RESULTS A significant decrease was observed in the levels of serum AST(2.07-fold), ALT(2.95-fold), and the blood lipid TG(2.34-fold) and TC(1.66-fold) in the dose of 20 mg/kg Ly-treated rats(P < 0.01), compared to the model group. Pretreatment with 5, 10 and 20 mg/kg of Ly significantly raised the levels of antioxidant enzyme SOD in a dose-dependent manner,to 90.95 ± 9.56, 109.52 ± 11.34 and 121.25 ± 10.68(P < 0.05, P < 0.01), as compared with the model group. Similarly, the levels of GSH were significantly increased(P < 0.05, P < 0.01) after the Ly treatment. Meanwhile, pretreatment with 5, 10 and 20 mg/kg of Ly significantly reduced MDA amount by 30.87, 45.51 and 54.49% in the liver homogenates, respectively(P < 0.01). The Ly treatment group showed significantly decreased levels of lipid products LDL-C(P < 0.05, P < 0.01), improved HDL-C level and significantly decreased content of FFA, compared to the model group(P < 0.05, P < 0.01). Furthermore, the Ly-treated group also exhibited a down-regulated TNF-α and CYP2E1 expression, decreased infiltration of liver fats and reversed histopathological changes, all in a dosedependent manner(P < 0.05, P < 0.01). CONCLUSION This study suggests that Ly has a protective effect on NAFLD, down-regulates expression of TNF-α, and that CYP2E1 may be one of the action mechanisms for Ly.