Study On The Hypoglycemic Effect And Mechanism Of Astragaloside Based On Intestinal Flora And Insulin Pathway

Diabetes is one of the most serious epidemics in the world.Insulin resistance is a key factor in the onset and progression of diabetes,mainly affecting the metabolic regulation of insulin,including glucose transport,glycogen synthesis and gene expression.There is increasing evidence that changes in the gut microbiota are related to insulin resistance and diabetes.Astragaloside Ⅳ is an important substance in astragalus and has a hypoglycemic effect.However,the mechanism of how astragaloside Ⅳ exerts a hypoglycemic effect by regulating intestinal flora and insulin signaling pathway is not yet clear.Therefore,by establishing an in vivo and in vitro diabetes model,this experiment explains the molecular mechanism of astragaloside glycemic effect from the perspective of intestinal flora and insulin signaling pathway,in order to provide new ideas and strategies for the prevention and treatment of diabetes.The specific resear-ch contents are as follows:Construction of mouse DM model and protection of astragaloside IV:High-fat and high-sugar feeding combined with 75 mg/kg streptozotocin(STZ)to construct the DM mouse model,and the pHysiological and biochemical indexes,oxidative stress level and histomorpHological changes of mice were detected and analyzed.Research results demonstrated that the levels of drinking water diet,FBG,OGTT,AUC,HOMA-IR,TG,LDL,and MDA in the DM group significantly increased(p<0.05),compared with the CON group;weight and SOD decreased significantly(p<0.05);liver and pancreas tissues are damaged to varying degrees.After treatment with different concentrations of astragaloside Ⅳ,the above parameters were significantly reversed,indicating that astragaloside Ⅳcan significantly improve the damage of DM mice.Protective effect of astragaloside IV on DM mice based on AMPK/SIRT1 and PI3K/AKT pathway:The expression of AMPK/SIRT1 and PI3K/AKT pathway proteins and mRNA were analyzed by Western blot and RT-PCR.Research results demonstrated that the protein and mRNA expression levels of AMPK,SIRT1,PI3K,and p-AKT in the DM group were significantly decreased(p<0.05),compared with the CON group;The protein and mRNA expression levels were significantly up-regulated(p<0.05).This suggests that astragaloside may improve the oxidative stress and insulin resistance by promoting the callback of AMPK/SIRT1 and PI3K/AKT pathway,and play a role in protecting DM mice.Study on the regulation of intestinal flora of astragaloside DM mice based on metagenomics:Metagenomics was used to detect stool samples from DM mice and astragaloside-protected mice.The results showed that at the level of phylum,the number of Bacteroidetes in the intestinal tract of mice in the astragaloside group increased,and the relative abundance of Firmicutes was reduced;At the genus level,beneficial bacteria that produce short-chain fatty acids,including Lachnospiraceae,Ruminococcaceae,Blautia,Butyrivibrio,Rikenellaceae,Alistipes,etc.,have increased.increased.Through environmental factor correlation analysis,it was found that the genus Riken,Alistipes,and Odoribacter can up-regulate the PI3K/AKT and AMPK/SIRT1 pathways and improve DM symptoms.It shows that astragaloside IV improves DM by regulating the overall balance of intestinal flora and affecting body metabolism.Construction of HepG2 insulin resistance model and protection of astragaloside Ⅳ:The IR-HepG2 model was constructed with high concentration of insulin,and glucose consumption and cell viability were measured to determine the modeling conditions.The results showed that glucose consumption was reduced while cell viability was not reduced when stimulated with 1×10-8 mol/L insulin for 48 hours,so it was selected as the best modeling condition to construct IR-HepG2 model.The biochemical oxidation indexes of HepG2 cells were detected,and the results showed that compared with the CON group,the glucose consumption of cells in the IR group was significantly reduced,the TG content was significantly increased,the MDA level was significantly increased,and the SOD activity was significantly reduced(p<0.05);Astragalus A at different concentrations After 48 hours of glycoside treatment,the above indexes of AST group cells were significantly improved(p<0.05).It shows that astragaloside can significantly improve the insulin resistance of IR-HepG2 cells.Protective effect of astragaloside Ⅳ on IR-HepG2 cells based on AMPK/SIRT1 and PI3K/AKT pathway:SIRT1 inhibitor and PI3K inhibitor were used to inhibit the related pathways.The expression of AMPK/SIRT1 and PI3K/AKT metabolic pathway proteins and mRNA were analyzed by Western blot and RT-PCR.The results showed that IR group and SIRT1 inhibitors EX527 and PI3K The expression of p-AMPK/AMPK,SIRT1,PI3K,p-AKT/AKT protein in IR+EX,IR+LY,AST+EX,and AST+LY cells treated with the inhibitor LY294002 was significantly down-regulated(p<0.05),and mRNA expression of AMPK,SIRT1,PI3K,and AKT was significantly reduced.The levels were also significantly down-regulated;p-AMPK/AMPK,SIRT1,PI3K,p-AKT/AKT protein expression and AMPK,SIRT1,PI3K,AKT mRNA expression were significantly up-regulated in the astragaloside group(p<0.05).It was verified that the pathogenesis of IR and DM is due to the inhibition of AMPK/SIRT1 and PI3K/AKT pathways,which can cause oxidative stress and insulin resistance.The protective mechanism of astragaloside IV is by up-regulating the expression of AMPK/SIRT1 and PI3K/AKT proteins to relieve injuries such as insulin resistance and oxidative stress.