Cassiae Semen improves non-alcoholic fatty liver disease through autophagy-related pathway

Objective:Cassiae Semen(CS,Juemingzi in Chinese)has been used for thousands of years in ancient Chinese history for relieving constipation,improving liver function as well as preventing myopia.Here we aimed to elucidate the anti-steatosis effect and underlying mechanism of CS against non-alcoholic fatty liver disease(NAFLD).Methods:High-performance liquid chromatography(HPLC)was used to identify the major components of CS water extract.Mice were fed with a high-fat and sugar-water(HFSW)diet to induce hepatic steatosis and then treated with CS.The anti-NAFLD effect was determined by measuring serum biomarkers and histopathology staining.Additionally,the effects of CS on cell viability and lipid metabolism in oleic acid and palmitic acid(OAPA)-treated HepG2 cells were measured.The expression of essential genes and proteins involved in lipid metabolism and autophagy signalings were measured to uncover the underlying mechanism.Results:Five compounds,including aurantio-obtusin,rubrofusarin gentiobioside,cassiaside C,emodin and rhein were simultaneously identified in CS extract.CS not only improved the diet-induced hepatic steatosis in vivo,as indicated by decreased number and size of lipid droplets,hepatic and serum triglycerides(TG)levels,but also markedly attenuated the OAPA-induced lipid accumulation in hepatocytes.These lipid-lowering effects induced by CS were largely dependent on the inhibition of fatty acid synthase(FASN)and the activation of autophagy-related signaling,including AMP-activated protein kinase(AMPK),light chain 3-II(LC3-II)/LC3-1 and autophagy-related gene5(ATG5).Conclusion:Our study suggested that CS effectively protected liver steatosis via decreasing FASN-related fatty acid synthesis and activating AMPK-mediated autophagy,which might become a promising therapeutic strategy for relieving NAFLD.