Department of Biochemistry and Biotechnology, Annamalai University, Annamalai Nagar-608002, Tamil Nadu, South India.
Eur J Pharmacol. 2011 Dec 5;671(1-3):95-101. doi: 10.1016/j.ejphar.2011.09.036. Epub 2011 Sep 21.
(-) Epicatechin rich foods and (-) epicatechin improve cardiovascular function. Consumption of diets rich in flavonoids is associated with reduced risk of cardiovascular diseases. Oxidative stress resulting from increased production of free radicals associated with decreased levels of antioxidants in the myocardium plays a major role in the pathogenesis of myocardial infarction. This study aims to evaluate the preventive effects of (-) epicatechin on oxidative stress in isoproterenol-induced myocardial infarcted rats. Male Wistar rats were pretreated with (-) epicatechin (20mg/kg body weight) daily for 21 days. After pretreatment, isoproterenol (100mg/kg body weight) was injected into the rats at an interval of 24h for two days to induce myocardial infarction. Isoproterenol induced rat's electrocardiogram showed elevated ST segments and significant increase in the activity of serum creatine kinase-MB, level of serum troponin-T and increased intensities of serum lactate dehydrogenase 1 and 2-isoenzymes. The rats also showed significant increased levels of heart lipid peroxidation products and significant decreased activities of heart superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and levels of reduced glutathione. Pretreatment with (-) epicatechin revealed significant protective effects on all the biochemical parameters and electrocardiogram investigated. Histopathology of myocardium confirmed the present findings. The in vitro study on the effects of (-) epicatechin on scavenging free radical 1,1-diphenyl-2-picrylhydrazyl revealed the free radical scavenging potential of (-) epicatechin. Thus, (-) epicatechin exerts protective effects against isoproterenol-induced oxidative stress thereby reducing cardiac tissue damage by its free radical scavenging and antioxidant effects.
(-)表儿茶素丰富的食物和(-)表儿茶素可改善心血管功能。富含类黄酮的饮食可降低心血管疾病的风险。心肌中自由基产生增加导致的氧化应激与抗氧化剂水平降低有关,在心肌梗死的发病机制中起着主要作用。本研究旨在评估(-)表儿茶素对异丙肾上腺素诱导的心肌梗死大鼠氧化应激的预防作用。雄性 Wistar 大鼠每天用(-)表儿茶素(20mg/kg 体重)预处理 21 天。预处理后,每天间隔 24 小时向大鼠注射异丙肾上腺素(100mg/kg 体重),连续两天诱导心肌梗死。异丙肾上腺素诱导的大鼠心电图显示 ST 段升高,血清肌酸激酶-MB 活性、血清肌钙蛋白-T 水平、血清乳酸脱氢酶 1 和 2-同工酶的强度显著增加。大鼠还表现出心脏脂质过氧化产物水平显著升高,心脏超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶、谷胱甘肽还原酶和还原型谷胱甘肽水平显著降低。(-)表儿茶素预处理对所有生化参数和心电图均显示出显著的保护作用。心肌组织病理学证实了这一发现。(-)表儿茶素对 1,1-二苯基-2-苦基肼清除自由基的体外研究揭示了(-)表儿茶素的自由基清除能力。因此,(-)表儿茶素对异丙肾上腺素诱导的氧化应激具有保护作用,通过清除自由基和抗氧化作用减轻心脏组织损伤。