Effect of aged garlic extract and s-allyl cysteine and their interaction with atenolol during isoproterenol induced myocardial toxicity in rats

OBJECTIVES: The study evaluates the cardioprotective effect of aged garlic extract (AGE) and its constituent; S-allylcysteine (SAC) and their interaction with atenolol during isoproterenol induced cardiac toxicity in rats. MATERIALS AND METHODS: Rats were administered AGE at two different doses of 2 ml/kg or 5 ml/kg orally whereas SAC was administered either at a dose 13.1 mg/kg or 32.76 mg/kg. The AGE or SAC was given alone or in combination with atenolol (6 mg/kg, p.o), every alternate day for three weeks. At the end of treatment, two doses of isoproterenol (150 mg/kg, s.c) were administered to rats. The electrocardiogram (ECG) was recorded followed by withdrawal of blood to estimate serum lactate dehydrogenase (LDH) and creatinine kinase-MB (CK-MB) activities. The activities of LDH, CK-MB as well as superoxide dismutase (SOD), catalase and thiobarbituric acid reactive substances (TBARS) were also determined in the heart tissue homogenate (HTH). RESULTS: The isoproterenol induced ECG changes were restored to normal in all treated groups. The AGE and SAC administration caused a decrease in serum LDH and CK-MB activities and an elevation of LDH and CK-MB activities in HTH. Atenolol alone or in combination with AGE and S-allylcsyteine demonstrated similar changes in biomarker activities. CONCLUSION: AGE showed dose-dependent cardioprotection. However, concurrent administration of SAC with atenolol (6 mg/kg, p.o) combated more effectively the myocardial dysfunction during isoproterenol induced cardiotoxicity in rats.