Pretreatment with quercetin ameliorates lipids, lipoproteins and marker enzymes of lipid metabolism in isoproterenol treated cardiotoxic male Wistar rats

Lipids and lipoproteins play an important role in the pathology of myocardial infarction. This manuscript reports the preventive effect of quercetin on lipids, lipoproteins and electrocardiogram in isoproterenol treated cardiotoxic male Wistar rats. Quercetin (10 mg/kg) was administered orally as pretreatment to Wistar rats daily for seven days. After pretreatment, rats were induced with myocardial infarction by subcutaneous injection of isoproterenol (100 mg/kg) at an interval of 24 h for two days. Quercetin pretreatment significantly (P < 0.05) lowered ST-segment elevation and decreased the levels of lipid peroxidation products in plasma and heart in isoproterenol treated cardiotoxic rats. Quercetin pretreatment also significantly (P < 0.05) reduced the levels of total cholesterol, triglycerides and free fatty acids in serum, heart and heart mitochondria and serum phospholipids in isoproterenol treated cardiotoxic rats. Significantly (P < 0.05) increased levels of heart and heart mitochondria phospholipids were observed in quercetin pretreated isoproterenol treated cardiotoxic rats. It's pretreatment also significantly (P < 0.05) reduced the levels of serum low-density lipoprotein and very low-density lipoprotein-cholesterol and significantly (P < 0.05) increased serum high density lipoprotein-cholesterol in isoproterenol treated cardiotoxic rats. In addition, quercetin significantly (P < 0.05) decreased the activity of 3-hydroxy-3-methyl glutaryl-Coenzyme A reductase in plasma and liver and significantly (P < 0.05) increased the activity of liver lecithin cholesterol acyl transferase in isoproterenol treated cardiotoxic rats. In vitro study on total antioxidant activity clearly revealed the antioxidant property of quercetin. Thus, the antioxidant activity of quercetin inhibits lipid peroxidation and prevents accumulation of lipids, alterations in lipoproteins and electrocardiogram in isoproterenol treated cardiotoxic rats.