Preventive effect of caffeic acid on lysosomal dysfunction in isoproterenol-induced myocardial infarcted rats.

We evaluated the preventive effect of caffeic acid (CA) on lysosomal enzymes in isoproterenol (ISO)-treated myocardial infarcted rats. Male albino Wistar rats were pretreated with CA (15 mg/kg) daily for a period of 10 days. After the pretreatment period, ISO (100 mg/kg) was subcutaneously injected to rats twice at an interval of 24 h. The activity of serum creatine kinase-MB and lactate dehydrogenase was increased significantly (P < 0.05) in ISO-induced myocardial infarcted rats. The levels of plasma thiobarbituric acid reactive substances and lipid hydroperoxides were significantly (P < 0.05) increased, and the level of plasma-reduced glutathione was significantly (P < 0.05) decreased in ISO-induced myocardial infarcted rats. The activities of lysosomal enzymes (beta-glucuronidase, beta-N-acetylglucosaminidase, beta-galactosidase, cathepsin-B and cathepsin-D) were increased significantly (P < 0.05) in the serum and heart of ISO-induced myocardial infarcted rats. ISO induction also resulted in decreased stability of membranes, which was reflected by lowered activities of beta-glucuronidase and cathepsin-D in different fractions except cytosol. Pretreatment with CA (15 mg/kg) to ISO-treated rats significantly (P < 0.05) prevented the changes in the activities of cardiac marker enzymes, the levels of lipid peroxidation products, reduced glutathione and the activities of lysosomal enzymes in the serum, heart, and subcellular fractions. Oral treatment with CA (15 mg/kg) to normal control rats did not show any significant effect. Thus, the results of our study showed that CA prevented the lysosomal membrane damage against ISO-induced myocardial infarction. The observed effects of CA are due to membrane-stabilizing, antilipo peroxidative, and antioxidant effects.

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.