Yangonin protects against cholestasis and hepatotoxity via activation of farnesoid X receptor in vivo and in vitro.

Cholestasis is a clinical syndrome with systemic and intrahepatic accumulation of excessive toxic bile acids that ultimately cause hepatobiliary injury. Recently obeticholic acid (OCA) which is a farnesoid X receptor (FXR) agonist was approved by FDA to treat cholestatic liver diseases, which provided us a newly therapeutic strategy against cholestasis. The purpose of the current study is to screen novel FXR agonists and verify the anti-cholestasis effect of yangonin in vivo and in vitro. The computational strategy of two-dimensional virtual screening was used to search for new FXR agonists, and dual-luciferase reporter gene assay was used to further demonstrate FXR activation by yangonin. Then, the hepatoprotective effect of yangonin via FXR activation against cholestasis and hepatotoxity was evaluated in mice and was investigated using FXR silence in cells. Yangonin was found to activate FXR to exert hepatoprotective effect against cholestatic liver injury. Dynamic change analysis of bile acids and gene analysis revealed that yangonin promoted bile acid efflux into bile and reduced hepatic uptake via the regulation of FXR-target genes Bsep, Mrp2 and Ntcp expression. Furthermore, yangonin modulated enzymes involved in bile acid synthesis and metabolism including Cyp7a1 Cyp8b1 and Sult2a1. In addition, yangonin promoted liver repair and suppressed liver inflammation. However, the changes in these genes and protein, as well as ameliorative liver histology induced by yangonin were abrogated by FXR antagonist guggulsterone in vivo and FXR siRNA in vitro. Yangonin produces protective effect against cholestasis via FXR activation. Yangonin may be an effective approach for the prevention and treatment for cholestatic liver diseases.