Protective effect of (-)-epigallocatechin-gallate (EGCG) on lipid peroxide metabolism in isoproterenol induced myocardial infarction in male Wistar rats: a histopathological study.

This study aims to evaluate the preventive effect of (-)-epigallocatechin-gallate (EGCG) on lipid peroxides, enzymatic and non-enzymatic antioxidants and histopathological findings in isoproterenol (ISO)-induced rats. Myocardial infarction (MI) is induced in rats by subcutaneous injection of ISO (100 mg/kg body weight) at an interval of 24h for 2 days. ISO-treated rats show a significant increase in the levels of thiobarbituric acid reactive substances, lipid hydroperoxides in plasma and heart and plasma uric acid and a significant decrease in the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione-S-transferase in heart and the levels of reduced glutathione, vitamin C and vitamin E in plasma and the heart and ceruloplasmin in plasma. Oral pretreatment with EGCG (10, 20 and 30 mg/kg body weight) daily for a period of 21 days show significant decrease in the levels of lipid peroxidation products and uric acid and improved the antioxidant status by increasing the activities of antioxidant enzymes and non-enzymic antioxidants. Histopathological findings of the myocardial tissue show the protective effect of EGCG in ISO-induced rats. The effect at a dose of 30 mg/kg of EGCG was more pronounced than that of the other two doses (10 and 20 mg/kg body weight). Thus, the present study reveals that EGCG exerts cardioprotective effect against ISO-induced MI due to its free radical scavenging and antioxidant effects, which maintains the tissue defense system against myocardial damage.