ABSTRACT
ABSTRACT Schisandra chinensis (Turcz.) Baill., Schisandraceae, is a well-known traditional Chinese medicine used mainly as a recipe for hepatoprotection. Modern researches have revealed that the hepatoprotection is related to its lignans and crude polysaccharide. In this study, we examined the effect and mechanism of S. chinensis total lignans on the liver injury induced by alcoholic. S. chinensis total lignans were extracted with ethanol extraction. The liver index, alanine aminotransferase and aspartate aminotransferase levels in serum of the rat culture supernatant were examined. The malondialdehyde level and superoxide dismutase activities in serum and liver tissue, and triacylglyceride content in liver tissue were tested. Western blot was conducted to determine cytochrome P450 2E1 expression in liver tissue of rats. The results showed that S. chinensis total lignans administration significantly inhibited alcohol-induced liver injury. In exploring the underlying mechanisms of S. chinensis total lignans action, we found that it significantly decreased Alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AKP), Glutamyl transpeptidase (γ-GT), reactive oxygen species (ROS) and malondialdehyde (MDA) level in livers/serum and inhibited the gene expression level of CYP2E1 in rat livers. The Nuclear factor erythroid-2 related factor 2 (Nrf2) gene expression and Nuclear factor erythroid-2 related factor 2 (Nrf2) protein nuclear transfer increased significantly, and significantly increased the expression of downstream target gene and protein heme oxygenase-1 (HO-1), Glutamate--cysteine ligase regulatory subunit (GCLM), NAD(P)H:quinine oxidoreductase 1 (NQO1). Moreover, S. chinensis total lignans decreased production of pro-inflammatory markers including Tumor Necrosis Factor-α (TNF-α), Interleukin-1beta (IL-1β) and Interleukin-6 (IL-6). In conclusion, these results suggested that the inhibition of alcohol-induced liver injury by S. chinensis total lignans is associated with its ability to inhibiting CYP2E1 activation and activating the Nrf2/Antioxidant response element(ARE) signaling pathway.