Al-Malki Abdulrahman L, Moselhy Said S
Biochemistry Department, Faculty of Science, King AbdulAziz University, Jeddah, Saudi Arabia.
Toxicol Ind Health. 2013 Mar;29(2):202-8. doi: 10.1177/0748233711430976. Epub 2012 Jan 27.
Nicotine is a major pharmacologically active and addictive component of tobacco smoke, which is regarded to be a primary risk factor in the development of cardiovascular and pulmonary diseases. Epicatechin is one of the most potent antioxidants present in the human diet. Particularly high levels of this compound are found in tea, apples and chocolate. It has been reported that tea extracts and/or its constituents have antibacterial, antiviral, antioxidative, antitumor and antimutagenic activities. Vitamin E is a major lipid-soluble antioxidant vitamin and free radical scavenger, presents as an integral component of cellular membranes and has important biological functions. The primary mechanism by which vitamin E is proposed to prevent cancer is through their antioxidant properties. The goal of this study is to evaluate the effect of epicatechin alone or combined with vitamin E in inhibiting the oxidative stress induced by nicotine in rats. Results obtained indicated that there was a significant elevation in the levels of malondialdhyde (MDA) in nicotine injected rats. The combined treatment (epicatechin + Vit E) group showed a potential reduction of these parameters more than individual treatment. The activities of superoxide dismutase, catalase and glutathione peroxidase were found significantly higher in combined treated than untreated rats. In nicotine group, a negative significant correlation between reduced glutathione and MDA (r = -0.92) was observed. In conclusion, these results suggested that the supplementation of diet with epicatechin and vitamin E provided antioxidant defense with strong chemopreventive activity against nicotine-induced carcinogenesis.
尼古丁是烟草烟雾中主要的具有药理活性和成瘾性的成分，被认为是心血管疾病和肺部疾病发生的主要危险因素。表儿茶素是人类饮食中最有效的抗氧化剂之一。在茶、苹果和巧克力中发现这种化合物的含量特别高。据报道，茶提取物和/或其成分具有抗菌、抗病毒、抗氧化、抗肿瘤和抗诱变活性。维生素E是一种主要的脂溶性抗氧化维生素和自由基清除剂，是细胞膜的组成成分，具有重要的生物学功能。维生素E预防癌症的主要机制是通过其抗氧化特性。本研究的目的是评估单独使用表儿茶素或与维生素E联合使用对抑制尼古丁诱导的大鼠氧化应激的影响。获得的结果表明，注射尼古丁的大鼠丙二醛（MDA）水平显著升高。联合治疗（表儿茶素+维生素E）组显示这些参数的降低比单独治疗更明显。联合治疗组中超氧化物歧化酶、过氧化氢酶和谷胱甘肽过氧化物酶的活性显著高于未治疗的大鼠。在尼古丁组中，观察到还原型谷胱甘肽与MDA之间呈显著负相关（r = -0.92）。总之，这些结果表明，在饮食中补充表儿茶素和维生素E可提供抗氧化防御，对尼古丁诱导的致癌作用具有强大的化学预防活性。
