Antioxidant and Anti-inflammatory Effects of Curcumin on CCl4 – induced Liver Fibrosis in Rats

Background: Liver fibrogenesis can lead to the development of cirrhosis and hepatocellular carcinoma. This study was designed to evaluate the hepatoprotective effect of curcumin on CCl4-induced fibrosis in rats and to assess its antioxidant and anti-inflammatory properties. Method: Rats were divided into four groups. Group 1 (n=10) was control vehicle, Group 2 (n=10); rats were injected with CCl4 (1 mL/Kg of 1:1v/v i.p. twice weekly for 12 week). Group 3 (n=10); rats were injected with similar doses of CCl4 and given oral curcumin (300 mg/kg) for 4 weeks after withdrawal of CCl4. Group 4 (n=10); rats were injected with similar doses of CCl4 and given curcumin orally (300 mg/kg) on the 6 th week of CCl4 treatment simultaneously for 6 weeks. Fibrosis was assessed histologically and by measuring liver hydroxyproline content. α-smooth muscle actin was detected immunohistochemically. Serum markers of liver damage and oxidative stress were quantified. TGF-β1expression in liver was determined by RT-PCR and quantified in plasma. Results: CCl4 resulted in elevation of ALT, AST, total bilirubin, TGF-β1 and liver hydroxyproline (P<0.05), whereas plasma total protein, glutathione peroxidase and superoxide dismutase activities were reduced (P<0.05). The histopathological changes were apparently ameliorated in the curcumin treated rats. Curcumin suppressed liver fibrosis indices and TGF-β1expression in hepatocytes following CCl4 injections (P<0.001). Curcumin enhanced liver antioxidant enzyme activities (P<0.001). Conclusion: These findings suggested that the antioxidant and anti-inflammatory effects of oral curcumin on hepatic fibrogenesis might be considered as its mechanisms to improve hepatic fibrogenesis.