Daidzein mitigates myocardial injury in streptozotocin-induced diabetes in rats

Aim: Present study focuses on the effect of daidzein in an experimental model of diabetic cardiomyopathy in rats. Materials and methods: Diabetes was induced in male Sprague Dawley rats by a single intraperitoneal injection of STZ at dose 55 mg/kg. Daidzein treatment was started after six weeks of diabetes induction. Animals received daidzein at a dose of 25, 50, and 100 mg/kg orally for the next four weeks. Key findings: Diabetic control animals showed significant prolongation in QT interval, PR interval, and R wave amplitude as compared to normal control animals. Treatment with daidzein at dose 100 mg/kg significantly normalized the QT interval, PR interval, and R wave amplitude. A significant reduction in QRS duration was observed in diabetic animals. Treatment with daidzein significantly improved the QRS duration after treatment. Hemodynamic parameters like systolic pressure (SBP), diastolic pressure (DBP) and mean atrial pressure (MAP) were found to be significantly decreased in diabetic animals. Treatment with daidzein at dose 100 mg/kg significantly improved the SBP, DBP, and MAP. Daidzein treatment prevented the loss of cardiac marker enzyme from heart tissue and also increased the level of AMPK and SIRT1 in plasma. Protein expression of NOX-4 and RAC-1 was also found to be reduced in cardiac tissue of daidzein treated animals. Daidzein treatment improved oxidative defense mechanism and reduced cardiac tissue necrosis and fibrosis. Significance: From the results, it can be concluded that daidzein mitigates the progression of diabetic cardiomyopathy by inhibiting NOX-4 induced oxidative stress in cardiac tissue.