Effect of silymarin on expression of TGF-β1 and CTGF of hepatic fibrosis in rats

【Objective】To investigate the effect and its mechanism of silymarin (SIL) on liver fibrosis rats induced by common bile duct ligation.【Methods】Sixty male SD rats were divided into three groups: Sham-operated control group,fibrosis model group,SIL treatment [50 mg/(kg·d)] group.Bile duct occlusive fibrosis model was prepared by common bile duct ligation,whereas the sham-operated group was used as control.After 4 weeks of treatment,the rats were killed.The serum level of hyaluronic acid (HA),laminin(LN) and Ⅲ procollagen(PCⅢ) was determined by radiommunoassay (RIA),and the liver histopathology was observed with light microscopy after HE and masson staining.The expressions of connective tissue growth factor (CTGF) and transforming growth factor-β1 (TGF-β1) in liver tissue were assessed by immunohistochemical staining.【Results】Compared with the model group,the serum level of HA,LN and PCⅢ decreased;the liver fibrosis was significantly improved in the rats treated with SIL;the expressions of TGF-β1 and CTGF decreased in the liver of the rats which were given SIL (P 0.01).Immunoreactive signals were mainly located in the cytoplasm of fiber space.【Conclusion】SIL may have protective effect in liver injury,and it can inhibit liver fibrosis induced by common bile duct ligation.The effect might possibly be attributed to its anti-inflammatory activity,together with its effect of down regulating CTGF and TGF-β1 .