Hepatic fibrosis in biliary-obstructed rats is prevented byGinkgo bilobatreatment

Abstract

To assess the antioxidant and antifibrotic effects of long-term Ginkgo biloba administration on liver fibrosis induced by biliary obstruction in rats. Liver fibrosis was induced in male Wistar albino rats by bile duct ligation and scission (BDL). Ginkgo biloba extract (EGb 761, 50 mg/kg.per d) or saline was administered for 28 d. At the end of the treatment period, all rats were killed. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) levels were determined to assess liver functions and tissue damage, respectively. Tumor necrosis factor-alpha (TNF-alpha) was also assayed in serum samples. Liver tissues were taken for determination of the hepatic malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity and collagen content. Production of reactive oxidants was monitored by chemiluminescence (CL) assay. Serum AST, ALT, LDH, and TNF-alpha levels were elevated in the BDL group as compared to control group and were significantly decreased by EGb treatment. Hepatic GSH level, depressed by BDL, was elevated back to control level in EGb-treated BDL group. Increase in tissue MDA level, MPO activity and collagen content due to BDL were also attenuated by EGb treatment. Furthermore, luminol and lucigenin CL values in BDL group increased dramatically compared to control and reduced by EGb treatment. Our results suggest that Ginkgo biloba protects the liver from oxidative damage following BDL in rats. This effect possibly involves the inhibition of neutrophil infiltration and lipid peroxidation; thus, restoration of oxidant and antioxidant status in the tissue.