Protective effect of caffeic acid on cardiac markers and lipid peroxide metabolism in cardiotoxic rats: an in vivo and in vitro study.

Myocardial infarction affects a large population in the world. Lipid peroxide metabolism plays an important role in the pathology of myocardial infarction. This study aims to evaluate the preventive effect of caffeic acid on lipid peroxides, antioxidants, cardiac marker enzymes, and histopathological findings in isoproterenol (ISO)-induced myocardial-infarcted male Wistar rats. Myocardial infarction was induced in rats by subcutaneous injection of ISO (100 mg/kg) at an interval of 24 hours for 2 days. The ISO-induced rats showed significant increase in the levels of thiobarbituric acid reactive substances, lipid hydroperoxides in the heart, plasma uric acid, and serum cardiac marker enzymes, and significant decrease in the activities of heart superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, and the levels of reduced glutathione, vitamin E, and vitamin C in the plasma and heart. Oral pretreatment with caffeic acid (15 mg/kg) daily for 10 days showed significant decrease in the levels of serum cardiac marker enzymes, heart lipid peroxidation products and plasma uric acid and significant increase in the levels of antioxidant system. Histopathology of myocardium also confirmed the protective effect of caffeic acid in myocardial-infarcted rats. In vitro study on total antioxidant activity (2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid assay) confirmed the strong antioxidant action of caffeic acid. Thus, the present study revealed that caffeic acid ameliorates cardiac damage in ISO-induced myocardial infarction by maintaining lipid peroxide metabolism due to its free radical scavenging and antioxidant effects. A diet containing caffeic acid may be beneficial to myocardial infarction.