Pretreatment with a combination of quercetin and alpha-tocopherol ameliorates adenosine triphosphatases and lysosomal enzymes in myocardial infarcted rats.

AIMS Membrane bound adenosine triphosphatases (ATPases) and lysosomal enzymes play an important role in the pathology of myocardial infarction. This study was aimed to evaluate the combined preventive effects of quercetin and alpha-tocopherol on membrane bound ATPases and lysosomal enzymes in isoproterenol induced myocardial infarcted rats. MAIN METHODS Male Wistar rats were pretreated with a combination of quercetin (10mg/kg) and alpha-tocopherol (10mg/kg) daily for 14 days. After the pretreatment period, isoproterenol (100mg/kg) was injected to rats at an interval of 24h for two days to induce myocardial infarction. The activities of ATPases and lysosomal enzymes were assayed. KEY FINDINGS Isoproterenol treated rats showed decreased levels of heart creatine kinase and lactate dehydrogenase. The activity of sodium potassium adenosine triphosphatase was decreased and the activities of magnesium adenosine triphosphatase and calcium adenosine triphosphatase were increased in isoproterenol treated rats. Also, the activities of beta-glucuronidase, beta-N-acetylglucosaminidase, beta-galactosidase, cathepsin-B and D were increased (serum and heart), but the activities of beta-glucuronidase and cathepsin-D were decreased in lysosomal fraction and increased in cytosolic fraction of the heart in isoproterenol treated rats. Furthermore, the heart lipid peroxidation products were increased in isoproterenol treated rats. Combined pretreatment with quercetin and alpha-tocopherol to isoproterenol treated rats normalized all the biochemical parameters studied. The observed effects are due to their membrane stabilizing property and this property might be due to decreased lipid peroxidation. SIGNIFICANCE Our study demonstrated that combined pretreatment was better than single pretreatment. This study may have significant impact on myocardial infarcted patients.