Combined Effect of Green Tea Extract and Vitamin E on Serum and Heart Tissue Lipids, Lipid Metabolizing Enzymes and Histopathological Alteration in Isoproterenol-Induced Myocardial Infarction in Rats

The present study investigated the protective effect of green tea and vitamin E combination on serum and heart tissue lipid profile, lipid metabolizing enzymes and histopathological changes in isoproteranol (ISO)-induced myocardial infarction in rats. Adult male albino rats, treated with ISO (200mg/kg, s.c.) for 2 consecutive days at an interval of 24 hrs. showed a significant increase in the levels of triglycerides (TG), total cholesterol (TC) and free fatty acids (FFA), in both serum and cardiac tissue. A rise in the levels of phospholipids (PL), low density lipoprotein (LDL) and very low density lipoprotein-cholesterol (VLDL-c) was also observed in the serum of isoproterenol-intoxicated rats. Further, a decrease in the level of high density lipoprotein-cholesterol (HDL-c) in serum and phospholipid levels, in the heart of isoproterenol-intoxicated rats was observed. Further a significant decrease in the activities of cholesterol ester synthetase (CES) and lecithin: cholesterol acyl transferase (LCAT) was shown whereas lipoprotein lipase (LPL) was found to be increased. Administration of alcoholic extract (60% polyphenols) of green tea (100 mg/kg/day, p.o.) and Vitamin E (DL-α-Tocopherol acetate) (100 mg/kg/day, p.o.) together for 30 consecutive days and challenged with ISO on day 29^th and 30^th , significantly attenuated these alterations and restored the levels of serum and heart lipids along with lipid metabolizing enzymes. Histopathological observations were also in correlation with the biochemical parameters. These findings indicate the protective effect of green tea and vitamin E in combination during ISO-induced myocardial infarction in rats.