Effects of Abscisic Acid on the Diabetic Changes in Rat Myocardium

The present study aims to find out the possible protective effect of abscisic acid (ABA) on the development of diabetic cardiomyopathy (DCM) in type 2 diabetic rats. Materials and methods: Fifty male rats divided into: normal control group, diabetic group and three diabetic treated groups with either pioglitazone, or ABA, or both pioglitazone and ABA for 16 weeks. At the end of experiment, ECG was recorded, biochemical measurement of serum glucose, insulin, lipid profile, troponin I, creatine kinase MB (CK-MB), Lactate dehydrogenase (LDH), interleukin-1 beta (IL-1β) and tumor necrosis factor- alpha (TNF-α) was done, caspase 3 and 9 activity in heart, RT- PCR for connexin-43(Cx43) and histopathological examination of cardiac tissue. Results: Treatment with ABA exerted positive effects on blood glucose and insulin levels that found to be reflected on heart weight/body weight ratio in diabetic rats. Also, it exerted significant improvement in cardiac markers and pro-inflammatory cytokines. DCM is associated with increased myocyte cell death that indicated by increasing caspase 3 and 9 that improved significantly by ABA. Also, results indicated that myocardial Cx43 mRNA levels were lesser in diabetic versus non-diabetic rats. Cx43 deterioration in diabetics may be behind the prolongation of the QRS and QTc, that improved by ABA. The histopathological findings showed that ABA improved diabetic cardiomyocyte necrosis and fibrosis. Conclusion: The diabetic rats benefit from ABA intake due to its hypoglycemic, anti-inflammatory and anti-apoptotic effects. So, intake of ABA in combination with anti-diabetic drugs may be beneficial for the management of type 2 diabetes mellitus.