Ameliorative effect of an ethanol extract of Embelia ribes fruits on isoproterenol-induced cardiotoxicity in diabetic rats

The present study explored the protective effect of Embelia ribes Burm. (Myrsinaceae) fruit ethanol extract on isoproterenol (ISO)-induced cardiomyopathy in streptozotocin (STZ)-induced diabetic rats. STZ (40 mg/kg, intravenously, single-injection)-induced diabetic rats had significantly (p<0.01) increased heart rate (HR), systolic blood pressure (SBP), blood glucose, HbA(1C), serum LDH, serum CK, and myocardial TBARS levels, and decreased blood glutathione and myocardial endogenous antioxidants, viz. SOD, CAT, and GSH levels in comparison to group I rats. ISO (5.25 and 8.5 mg/kg, s.c., for two consecutive days) administration produced myocardial necrosis as evidenced by a significant (p < 0.01) increase in HR, SBP, serum LDH, serum CK, and myocardial TBARS levels and a significant (p < 0.01) decrease in blood glutathione, and myocardial endogenous antioxidant levels in comparison to group I rats. Further, ISO administration to diabetic rats showed a significant (p < 0.01) increase in SBP, blood glucose, and HbA(1c) levels along with a significant (p<0.01) decrease in HR, blood glutathione, serum LDH, serum CK, myocardial TBARS, SOD, CAT, and GSH levels as compared to ISO-only treated (i.e. group IV) rats. Forty days treatment of Embelia ribes ethanol extract (200 mg/kg) to pathogenic (STZ + ISO treated) rats resulted in a significant (p<0.01) increase in HR, blood glutathione, serum LDH, and myocardial endogenous antioxidant levels with a significant (p < 0.01) decrease in SBP, blood glucose, HbA(1C), serum CK, and myocardial TBARS levels as compared to pathogenic (STZ + ISO treated) rats. The study demonstrates the ability of Embelia ribes extract to attenuate ISO-induced oxidative stress in diabetic rats, enhancing cellular antioxidant defense.