Thymol attenuates altered lipid metabolism in β-adrenergic agonist induced myocardial infarcted rats by inhibiting tachycardia, altered electrocardiogram, apoptosis and cardiac hypertrophy

The ability of thymol to attenuate the altered lipid metabolism by inhibiting tachycardia, altered electrocardiogram, apoptosis and cardiac hypertrophy in isoproterenol induced myocardial infarcted rats was evaluated. Rats were pre-and co-treated with thymol (7.5 mg/kg) for a period of 7 days. Isoproterenol (100 mg/kg) was injected subcutaneously into rats at an interval of 24 h for two days (6th and 7th day) to induce myocardial infarction. Isoproterenol induced rats showed increased levels of serum cardiac troponins, heart weight, left ventricular hypertrophy, elevated ST segments and tachycardia with increased levels of serum and heart lipids, alterations in the levels/activities of lipoproteins and lipid marker enzymes. Furthermore, isoproterenol induced myocardial infarcted rats showed a decrease in the expression of myocardial B-cell leukemia/lymphoma-2 (bcl-2) gene and an increase in the expression of myocardial bcl-2 associated-x (bax)-gene. Thymol pre-and co-treatment showed significant protective effects on all the biochemical parameters and molecular mechanisms studied. The in vitro studies confirmed its potent free radical scavenging effect. Thus, thymol attenuates the altered lipid metabolism by its antitachycardial, antihypertrophic, anti-apoptotic and antihyperlipidemic effects in isoproterenol induced myocardial infarcted rats.