Mechanism of Tea Polyphenols in Improving Glucose and Lipid Metabolism in Diabetic Rats Based on AMPK Pathway
Objective:To explore how tea polyphenols regulate glucose and lipid metabolism in diabetic rats through the AMP-activated protein kinase(AMPK)pathway.Methods:Total 45 six-week-old SD rats were screened by the glucose tolerance test and divided into the normal group of 10 rats and the model group of 35 rats according to the random number table method.After successfully establishing the diabetic model,the remaining 30 rats were stratified by body weight and blood glucose levels into the model group,the metformin group,and the tea polyphenol group,with 10 rats in each group.Each group was gavaged every afternoon:the normal and model groups received sterile saline,the metformin group received metformin solution,and the tea polyphenol group received tea polyphenols.After 120 days of intervention,fasting blood glucose(FBG),total cholesterol(TC),triglycerides(TG),high-density lipoprotein cholesterol(HDL-C),and low-density lipoprotein cholesterol(LDL-C)were measured in each group.Enzyme linked immunosorbent assay was used to detect liver acetyl-CoA carboxylase(ACC)and hormone-sensitive lipase(HSL).Real-time fluorescence quantification was used to detect liver ACC mRNA,transcription factor sterol regulatory element-binding protein 1(SREBP-1)mRNA,3-hydroxy-3-methylglutaryl-CoA reductase(HMGCR)mRNA.Western blotting was used to detect liver AMPKα1,P-AMPKα1,SREBP1,HMGCR,carnitine palmitoyltransferase 1(CPT1),glucose transporter 4(GLUT4),and phosphoenolpyruvate carboxykinase(PEPCK).Results:Compared with the normal group,the general condition of rats in the model group was poor,FBG,TG,TC,LDL-C,ACC were increased(P＜0.05),SREBP1,HMGCR protein,and mRNA expression were increased(P＜0.05),CPTI,PEPCK protein expression were increased(P＜0.05),HDL-C,HSL were decreased(P＜0.05),AMPKα1,P-AMPKα1,GLUT4 protein expression were decreased(P＜0.05).Compared with the model group,the general condition of rats in the tea polyphenol group improved,TG,LDL-C,ACC were decreased(P＜0.05),SREBP1,HMGCR protein and mRNA expression were decreased(P＜0.05),PEPCK protein expression was decreased(P＜0.05),HDL-C,HSL were increased(P＜0.05),AMPKα1,P-AMPKα1,GLUT4,CPT1 protein expression were increased(P＜0.05).Compared with the metformin group,the tea polyphenol group showed an increase in TC(P＜0.05),with no statistical significance in the relative expression of FBG,TG,LDL-C,HDL-C,HSL,ACC,ACC mRNA,HMGCR mRNA,SREBP1 mRNA,AMPKα1,P-AMPKα1,SREBP1,HMGCR,CPT1,GLUT4,PEPCK(P＞0.05).Conclusion:Tea polyphenols may improve glucose and lipid metabolism in diabetic rats by regulating the AMPK pathway,affecting HSL,HMGCR,SREBP1,CPTI,GLUT4,and PEPCK.
diabetestea polyphenolsmetforminAMP-activated protein kinase pathwayglucose and lipid metabolismrat
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维普
