Drugs Research For Metabolic Syndrome Therapy Based On The Regulation Of Metabolism And Immunity

Objective:Metabolic syndrome(MS)is a chronic disease with metabolic disorders and low-grade inflammation as its main features.The natural products or derivatives of monocoumarin ADMC and ginsenoside G-Rh2 isolated from the traditional Chinese medicine Yinchen and ginseng have anti-inflammatory,hypoglycemic and other pharmacological activities.The purpose of our study was to confirm the therapeutic effects of the two monomer compounds on MS,and further to explore their mechanism.Methods:(1)We adopted a high-fat diet feded C57BL/6J mice for 3 months to establish MS model,and performed intragastric administration for 4 weeks.Insulin tolerance test(ITT)and oral glucose tolerance test(OGTT)were conducted to investigate the insulin sensitivity.Using the blood glucose meter and ELISA kit measured fasting blood glucose(FBG)and serum insulin content to calculate the insulin resistance(IR)index by the steady-state model HOMA-IR.(2)Weighed mice body weight and adipose tissue to calculate fat index.Adopted HE,oil red O staining to observe the fatty liver or hepatitis.Biochemical kit were used to detect mice serum lipids,including TC,TG,NEFA,LDL-C and HDL-C.(3)IR-cells model were established by low glucose/high insulin-treated mouse hepatocytes AML12,and the effect of ADMC on glucose metabolism was measured using fluorescent reagent 2-NBDG and glucose kit.The changes of lipid metabolism were investigated in high glucose/high lipid environment cultured AML12 cells.(4)Adopted non-target lipid metabolomics technology to analyze the effect of G-Rh2 on lipid metabolism patterns in MS mice liver.(5)The effects of ADMC and G-Rh2 on key enzymes of glycolysis,insulin signaling pathway PI3K/AKT,and related genes of lipid synthesis and decomposition were detected by PCR.(6)The numbers of immune cells in mice thymus,spleen and liver tissues were detected by flow cytometry.TNF-α,IL-6 in serum were detected by ELISA kits.The expression of CD68 and CD11c in pancreas were examined by Immunohistochemistry to investigate tissue inflammation.Results:(1)ADMC significantly reduced the IR index,FBG,the area under the curve(AUC)of ITT and OGTT in MS mice.G-Rh2 slightly reduced the AUC of OGTT and IR index,but had no significant effect on FBG.(2)Both ADMC and G-Rh2 reduced mice body weight and fat index,which suggested obesity was significantly prevented.ADMC and G-Rh2 protected liver from excessive fat accumulation and inflammatory infiltration.ADMC down-regulated blood lipids mainly by NEFA and LDL-C,while G-Rh2 decreased TC,NEFA and LDL-C levels.(3)ADMC significantly enhanced the uptake and consumption of glucose in IR-AML12 cells.Simultaneously,ADMC inhibited the accumulation of lipid droplets and TC,TG contents in high glucose/high lipid stimulated AML12 cells.(4)G-Rh2 significantly down-regulated 74 lipid metabolites in the liver,mainly including TGs and phosphatidylcholines.(5)ADMC promoted the m RNA expression of PI3K/AKT in metabolic organs(liver,skeletal muscle,adipose tissues)and glycolytic genes HK2,Pfkfb1/2/3 in liver of MS mice,which was consistent with AML12 cells.G-Rh2 significantly down-regulated fatty acid synthesis genes SREBP1,ACC,FASN,and up-regulated lipolytic genes ADPN,Atgl,and Sir T3 in liver.(6)ADMC reduced TNF-α,IL-6,AST/ALT levels in serum,and reduced the numbers of T cells in liver and pancreatic CD11c~+macrophages.It regulated thymic T cells,macrophages and Treg cells balanced,slightly down-regulated T cells in spleen.G-Rh2 also reduced serum TNF-α,IL-6,liver index,AST/ALT levels in liver homogenate,T cells and NK cells in spleen,significantly increased the marrow-derived suppressor cells(MDSCs).But G-Rh2 had no effect on CD4~+T,CD8~+T,NK and Treg cells in the thymus.Conclusion:(1)ADMC has obvious effect on MS,which is manifested in alleviating IR and obesity,increasing insulin sensitivity and glucose tolerance,controlling hyperglycemia and hyperlipidemia,and protecting liver from fat accumulation or hepatitis.(2)ADMC maintains the metabolic homeostasis of MS mice,enhances insulin/PI3K/AKT signaling in metabolic organs,accelerates liver uptake of glucose,and promotes glycolysis and lipolysis.(3)ADMC regulates the systematic immune balance via inhibiting T cells and macrophages in the thymus and spleen to exert anti-inflammatory effects in liver and pancreas tissues,which maintain the normal metabolic functions.(4)The efficacy of G-Rh2 in MS treatment is main reflected in lipid metabolism,which significantly inhibits obesity,hyperlipidemia and fatty liver.G-Rh2slightly alleviates IR,but has a poor effect on FBG.(5)The key mechanism of G-Rh2to MS is improving the lipid metabolism pattern in liver via inhibiting fatty acid synthesis and promoting lipolysis,further preventing the excessive production of lipid metabolites,mainly glycerides.Thereby maintains liver metabolism and blood lipids homeostasis.(6)G-Rh2 regulates the ratio of Th1 immune cells/MDSCs in peripheral immune organs(spleen)and reduces inflammatory factors,which is of great significance in resisting chronic low-grade inflammation in liver and adipose tissue.Innovative points:This is the first time to explore the efficacy and mechanism of two traditional Chinese medicine monomers for MS treatment from both metabolism and immunity.We expecte to discover some specific drugs and provide a new strategy for treating MS based on the mutual regulation of metabolism and immunity.