Discovery of 3,7-dimethoxyflavone that inhibits liver fibrosis based on dual mechanisms of antioxidant and inhibitor of activated hepatic stellate cell.

The important pathway toward liver fibrosis is the TGF-β1-induced activation of hepatic stellate cells (HSCs). To discover chemicals to inhibit liver fibrosis, we screened 3000 chemicals using cell array system where human HSCs line LX2 cells are activated with TGF-β1. We discovered 3,7-dimethoxyflavone (3,7-DMF) as a chemical to inhibit TGF-β1-induced activation of HSCs. In the thioacetamide (TAA)-induced mouse liver fibrosis model, 3,7-DMF treatment via intraperitoneal or oral administration prevented liver fibrosis as well as reversed the established fibrosis in the separate experiments. It also reduced liver enzyme elevation, suggesting protective effect on hepatocytes because it has antioxidant effect. Treatment with 3,7-DMF induced antioxidant genes, quenches ROS away, and improved the hepatocyte condition that was impaired by H 2 O 2 as reflected by restoration of HNF-4α and albumin. In the TAA-mouse liver injury model also, TAA significantly increased ROS in the liver which led to decrease of albumin and nuclear expression of HNF-4α, increase of TGF-β1 and hepatocytes death, accumulation of lipid, and extra-nuclear localization of HMGB1. Treatment of 3,7-DMF normalized all these pathologic findings and prevented or resolved liver fibrosis. In conclusion, we discovered 3,7-DMF that inhibits liver fibrosis based on dual actions; antioxidant and inhibitor of TGF-β1-induced activation of HSCs. [Display omitted] • We developed a cell array system to identify new compounds capable of inhibiting liver fibrosis, using the human hepatic stellate cells activated by TGF-β1. • We identified 3,7-DMF as a potential chemical to prevent liver fibrosis after injury. • Daily oral administration of 3,7-DMF effectively resolved established liver fibrosis after injury. • 3,7-DMF protected hepatocytes through two mechanisms: scavenging ROS and decreasing the expression of TGF-β1. • 3,7-DMF had a protective effect on injured liver tissues by restoring hepatocyte functional genes, inhibiting hepatic steatosis, regenerating injured hepatocytes, and inhibiting activated HSCs. [ABSTRACT FROM AUTHOR]