Ganoderma lucidum polysaccharide peptide alleviates hepatoteatosis via modulating bile acid metabolism dependent on FXR-SHP/FGF

OBJECTIVE Ganoderma lucidum polysaccharide peptide(GLPP)is a group of extract from Ganoderma lucidum with a molecular mass of approximately 5×10^5,which ratio of polysaccharide to peptide is approximately 95%/5%.The purpose of this study was to determine whether GLPP has therapeutic effect on Non-alcoholic fatty liver disease(NAFLD).METHODS Ob/ob mouse model and ApoC3 transgenic mouse model were used for exploring the effect of GLPP on NAFLD.Key metabolic pathways and enzymes were identified by metabolomics combining with KEGG and PIUmet analyses and key enzymes were detected by Western blotting.Hepatosteatosis models of HepG2 cells and primary hepatocytes were used to further confirm the therapeutic effect of GLPP on NAFLD.RESULTS GLPP administrated for a month alleviated hepatosteatosis,dyslipidemia,liver dysfunction and liver insulin resistance.Pathways of glycerophos⁃pholipid metabolism,fatty acid metabolism and primary bile acid biosynthesis were involved in the therapeutic effect of GLPP on NAFLD.Detection of key enzymes revealed that GLPP reversed low expression of CYP7A1,CYP8B1,FXR,SHP and high expression of FGFR4 in ob/ob mice and ApoC3 mice.Besides,GLPP inhibited fatty acid synthesis by reducing the expression of SREBP1c,FAS and ACC via a FXR-SHP dependent mechanism.Additionally,GLPP reduced the accumulation of lipid droplets and the content of TG in HepG2 cells and primary hepatocytes induced by oleic acid and palmitic acid.CONCLUSION GLPP significantly improves NAFLD via regulating bile acid synthesis dependent on FXR-SHP/FGF pathway,which finally inhibits fatty acid synthesis,indicating that GLPP might be developed as a ther⁃apeutic drug for NAFLD.