Muzandu Kaampwe, Ishizuka Mayumi, Sakamoto Kentaro Q, Shaban Zein, El Bohi Khlood, Kazusaka Akio, Fujita Shoichi
Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
Toxicol Appl Pharmacol. 2006 Sep 15;215(3):330-40. doi: 10.1016/j.taap.2006.03.006. Epub 2006 May 2.
Peroxynitrite formed by the reaction of superoxide and nitric oxide is a highly reactive species with a role in various pathological processes such as cancer, chronic inflammation, and cardiovascular and neurological diseases. In the present study, the effect of the carotenoids, lycopene and beta-carotene, on peroxynitrite-mediated modifications in plasmid DNA as well as cellular DNA and proteins were investigated. In pUC18 plasmid DNA, these carotenoids strongly inhibited DNA strand breaks caused by peroxynitrite generated from 3-morpholinosydnonimine (SIN-1). SIN-1 was also used to determine effects on DNA damage and protein tyrosine nitration in Chinese hamster lung fibroblasts. SIN-1 dose-dependently increased nitration of proteins in cells above basal levels as determined by Western blotting. This nitration was inhibited in the presence of the uric acid as well as lycopene. Physiological concentrations (0.31-10 microM) of lycopene and beta-carotene also had protective effects on DNA damage, as measured by the comet assay. Lycopene significantly reduced DNA damage particularly, in the median range of concentrations (2.5 microM). The protective effects of lycopene and beta-carotene could be due to their scavenging of reactive oxygen (ROS) and/or nitrogen species (RNS) as they reduce the amount of intracellular ROS/RNS produced following treatment with SIN-1 by as much as 47.5% and 42.4%, respectively. The results obtained in this study suggest that carotenoids may alleviate some of the deleterious effects of peroxynitrite and possibly other reactive nitrogen species as well in vivo.
超氧化物与一氧化氮反应生成的过氧亚硝酸盐是一种高反应活性物质，在多种病理过程中发挥作用，如癌症、慢性炎症以及心血管和神经疾病。在本研究中，研究了类胡萝卜素番茄红素和β-胡萝卜素对过氧亚硝酸盐介导的质粒DNA以及细胞DNA和蛋白质修饰的影响。在pUC18质粒DNA中，这些类胡萝卜素强烈抑制由3-吗啉代-sydnonimine（SIN-1）产生的过氧亚硝酸盐引起的DNA链断裂。SIN-1还用于测定对中国仓鼠肺成纤维细胞中DNA损伤和蛋白质酪氨酸硝化的影响。通过蛋白质印迹法测定，SIN-1剂量依赖性地增加细胞中蛋白质的硝化水平，使其高于基础水平。在尿酸以及番茄红素存在的情况下，这种硝化作用受到抑制。通过彗星试验测定，生理浓度（0.31 - 10 microM）的番茄红素和β-胡萝卜素对DNA损伤也具有保护作用。番茄红素尤其在中等浓度范围（2.5 microM）时能显著减少DNA损伤。番茄红素和β-胡萝卜素的保护作用可能归因于它们对活性氧（ROS）和/或氮物种（RNS）的清除，因为它们分别将用SIN-1处理后产生的细胞内ROS/RNS量减少了47.5%和42.4%。本研究获得的结果表明，类胡萝卜素在体内可能减轻过氧亚硝酸盐以及可能其他活性氮物种的一些有害影响。
