Deoxyschizandrin ameliorates obesity and non-alcoholic fatty liver disease: Involvement of dual Farnesyl X receptor/G protein-coupled bile acid receptor 1 activation and leptin sensitization.

Abstract

Natural dual farnesyl X receptor (FXR)/G protein-coupled bile acid receptor 1 (TGR5) activators have received little attention in the management of metabolic diseases. Deoxyschizandrin (DS), a natural lignan, occurs in S. chinensis fruit and has potent hepatoprotective effects, whereas its protective roles and mechanisms against obesity and non-alcoholic fatty liver disease (NAFLD) are largely elusive. Here, we identified DS as a dual FXR/TGR5 agonist using luciferase reporter and cyclic adenosine monophosphate(cAMP) assays. DS was orally or intracerebroventricularly administrated to high-fat diet-induced obesity (DIO) mice, and methionine and choline-deficient L-amino acid diet (MCD diet)-induced non-alcoholic steatohepatitis to evaluate its protective effects. Exogenous leptin treatment was employed to investigate the sensitization effect of DS on leptin. The molecular mechanism of DS was explored by Western blot, quantitative real-time PCR analysis, and ELISA. The results showed that DS activated FXR/TGR5 signaling and effectively reduced NAFLD in DIO and MCD diet-fed mice. DS countered obesity in DIO mice by promoting anorexia and energy expenditure and reversing leptin resistance, involving both peripheral and central TGR5 activation and leptin sensitization. Our findings indicate that DS may be a novel therapeutic approach for alleviating obesity and NAFLD through regulating FXR and TGR5 activities and leptin signaling.