Attenuation of the cardiac inflammatory changes and lipid anomalies by (−)-epigallocatechin-gallate in cigarette smoke-exposed rats

Abstract

Cigarette smoking is a major risk factor for cardiovascular diseases and exerts negative effects on the lipid profile. This study was aimed to evaluate the preventive role of (-)-epigallocatechin-gallate (EGCG) on lipid metabolism and cardiac inflammatory changes in cigarette smoke (CS) induced myocardial dysfunction. Adult male albino rats were exposed to side stream CS for a period of 12 weeks and simultaneously administered with EGCG (20 mg/kg b.w./day, p.o.). Exposure to CS showed significant increased (P < 0.05) activities of cardiac injury markers such as, creatine kinase-MB (CKMB) and lactate dehydrogenase (LDH) in serum and subsequent decrease in these enzyme activities in heart. A significant increase (P < 0.05) in serum total cholesterol, fatty acids, phospholipids, and triglycerides were observed in CS exposed rats, along with elevated low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) cholesterol and decreased high density lipoprotein (HDL) cholesterol. In myocardium, total cholesterol, fatty acids and triglycerides were increased, whereas the phospholipids were found to be decreased. Cardiac lecithin: cholesterol acyl trasferase (LCAT), lipoprotein lipase (LPL), and plasma LCAT activities were significantly decreased (P < 0.05) on CS exposure. Supplementation of EGCG reverted the cardiac injury markers, abnormalities of lipid profile, and lipid-metabolizing enzymes in serum and myocardium. Western blot analysis showed a significant increase in protein expression levels of nuclear factor kappa-B (NF-κB), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), and inducible nitric oxide synthase (iNOS) in heart of CS exposed rats. EGCG-treated rats showed a significant decrease in the expression of inflammatory markers. Our data suggest that chronic CS causes lipidemic anomalies and cardiac inflammatory aberrations which may promote cardiac dysfunction and that the antioxidant EGCG exerts a cardio protective effect via reduction of oxidative stress.