Effects of extract from Ginkgo biloba on carbon tetrachloride-induced liver injury in rats

Abstract

To study the effects of extract from Ginkgo biloba (EGb) containing 22% flavonoid and 5% terpenoid on chronic liver injury and liver fibrosis of rats induced by carbon tetrachloride (CCl(4)). All rats were randomly divided into control group, CCl(4)-treated group, colchicine-treated group and EGb-protected group. Chronic liver injury was induced in experimental groups by subcutaneous injection of CCl(4) and fed with chows premixed with 79.5% corn powder, 20% lard and 0.5% cholesterol (v/v). EGb-protected group was treated with EGb (0.5 g/kg body weight per day) for 7 wk. At the end of wk 8, all the rats were killed. Liver function, liver fibrosis, oxidative stress and expression of transforming growth factor beta1 (TGF-beta1), a-smooth muscle actin (alpha-SMA) and type I collagens in liver were determined. In addition, pathology changes of liver tissue were observed under light microscope. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and albumin (Alb) in EGb-protected group were notably improved as compared with the CCl(4)-treated group (P < 0.01). The contents of serum hyaluronic acid (HA), type III procollagen (PCIII), type IV collagen (CIV) and the expression of hepatic tissue TGF-beta1, alpha-SMA and type I collagen in EGb-protected group were significantly lower than those in CCl(4)-treated groups (P < 0.05, P < 0.01). The degrees of liver fibrosis in EGb-protected groups were lower than those in CCl(4)-treated groups (6.58 +/- 1.25 vs 9.52 +/- 2.06, P < 0.05). Compared to the CCl(4)-treated group, the levels of plasma glutathoine peroxidase (Se-GSH-Px), superoxide dismutase (SOD) and malondialdehyde (MDA) were strikingly improved also in EGb-protected group (P < 0.05, P < 0.01). EGb resists oxidative stress and thereby reduces chronic liver injury and liver fibrosis in rats with liver injury induced by CCl(4).