Genistein attenuates D-GalN induced liver fibrosis/chronic liver damage in rats by blocking the TGF-β/Smad signaling pathways

Abstract Background and aim Genistein is a major isoflavonoid abundantly found in soy. Earlier genistein has been reported to possess protective effect against a multitude of disorders including cancer. Previously we demonstrated the protective effects of Genistein in d -Galactosamine (D-GalN) induced fulminant hepatic failure (FHF) in rats. In present study, we evaluated the hepatoprotective activity of Genistein in rat model of chronic liver damage and liver fibrosis. Methods Liver fibrosis was induced by intraperitoneal injection of D-GalN (250 mg/kg BW) twice a week for 12 weeks. Genistein (5 mg/kg BW) was given via intra-gastric route as co-treatment daily for 12 weeks. Results Genistein co-treatment significantly attenuated D-GalN-induced chronic liver damage and liver fibrosis as evident from a significant amelioration in functional impairment, including inhibition of the activation of Hepatic stellate cells (HSC), decreased expression in alpha smooth muscle actin (α-SMA) and accumulation of collagen matrix, and an elevation in serum alanine transaminase (ALT) and aspartate transaminase (AST) level. In addition Genistein co-treatment was associated with elevated expression of hepatic Smad7, which ultimately blunts the expression of TGF-β and the activation of TGF-β/Smad signaling. Furthermore Genistein significantly prevented the histopathological changes induced by D-GalN. Conclusion Our results suggest that Genistein could be a novel therapeutic/nutraceutical agent in treating chronic liver damage and liver fibrosis. In addition our study also suggests a possible mechanism of action in which Smad7-induced inhibition of TGF-β/Smad2/3 can be a central mechanism by which Genistein protects liver from chronic injury.