The Protective Effect Of Puerarin On Type 2 Diabetic Cardiomyopathy Rats

Objective: To investigate the protective effect of puerarin,an extract of Pueraria lobata,on type 2 diabetic cardiomyopathy rats.Methods: Sixty SPF SD rats were randomly divided into seven groups:normal control group(CON),high-fat model group(GM),high-fat model treatment group(GM+P),diabetic cardiomyopathy model(DCM)group,puerarin(Pue)low-dose treatment group(P+L),Pue high-dose treatment group(P+H),positive control group(3-MA).Except for the normal group,the other groups were fed with high-fat diet for 12 weeks.Among them,the DCM group,the P+L group,the P+L group and the 3-MA group were intraperitoneally injected with streptozotocin(STZ,25 mg/kg/time)twice,and 72 h after the intervention,the tail vein blood samples were taken for detection.When the fasting blood glucose ≥16.7 mmol/L,the animal model of type 2 diabetic cardiomyopathy was regarded as successful,and the high-fat diet feeding was continued for 1 month.After the beginning of treatment,the weight and blood glucose of SD rats in each group were recorded once a week.HE staining was used to detect myocardial histological changes in each group;cardiac weight index of rats was compared;serum creatine kinase isozyme(CK-MB)level,brain natriuretic peptide(BNP)and insulin level were detected by ELISA;The expression of Beclin1 and P62 in myocardium was detected by immunohistochemistry,and the expression of LC3 was detected by Western blot.Results:Compared with GM group,DCM group rats had significantly higher blood glucose,the body weight was decreased significantly and the ventricular mass index was significantly increased(P<0.05).The levels of CK-MB and BNP in serum were significantly increased(P<0.05);the expression of Beclin-1 in myocardial tissue was significantly increased,the expression of P62 was significantly decreased,and the ratio of LC3II/LC3 I was significantly increased.In addition,compared with the CON group,the DCM group rats had disordered cardiomyocyte arrangement,large interstitial space,hypertrophy of cardiomyocytes,enlargement of some nuclei,etc.the blood glucose level of P+H group rats was significantly lower than rats of DCM group(P<0.05).The level of insulin in serum was increased in P+H group,while CK-MB and BNP levels were decreased in P+L group,P+H group and 3-MA group.After intraperitoneal injection of puerarin and 3-MA,the expression of Beclin-1in myocardial tissue of rats was inhibited,the expression of P62 protein was significantly increased and LC3II/LC3 I was significantly decreased in P+L group,P+H group and 3-MA group(P<0.05).Conclusion: Puerarin has a protective effect on type 2 diabetic cardiomyopathy rats,which may be related to reducing blood glucose,serum CK-MB and BNP levels,improving myocardial morphological expression,and inhibiting autophagy in DCM rats.