Sruthi S, Millot N, Mohanan P V
Toxicology Division, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, 695 012, Kerala, India.
Département Nanosciences, Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS/Université de Bourgogne Franche-Comté, 9 av. A. Savary, BP 47 870, 21 078 Dijon, France.
Int J Biol Macromol. 2017 Oct;103:808-818. doi: 10.1016/j.ijbiomac.2017.05.088. Epub 2017 May 17.
Zinc oxide nanoparticles (ZnO NPs) are widely used in a variety of products and are currently being investigated for biomedical applications. However, they have the potential to interact with macromolecules like proteins, lipids and DNA within the cells which makes the safe biomedical application difficult. The toxicity of the ZnO NP is mainly attributed reactive oxygen species (ROS) generation. Different strategies like iron doping, polymer coating and external supply of antioxidants have been evaluated to minimize the toxic potential of ZnO NPs. Melatonin is a hormone secreted by the pineal gland with great antioxidant properties. The melatonin is known to protect cells from ROS inducing external agents like lipopolysaccharides. In the present study, the protective effect of melatonin on ZnO NPs mediated toxicity was evaluated using C6 glial cells. The Cytotoxicity, mitochondrial membrane potential and free radical formation were measured to study the effect of melatonin. Antioxidant assays were done on mice brain slices, incubated with melatonin and ZnO NPs. The results of the study reveal that, instead of imparting a protective effect, the melatonin pre-treatment enhanced the toxicity of ZnO NPs. Melatonin increased antioxidant enzymes in brain slices.
氧化锌纳米颗粒（ZnO NPs）广泛应用于各种产品中，目前正在进行生物医学应用方面的研究。然而，它们有可能与细胞内的蛋白质、脂质和DNA等大分子相互作用，这使得安全的生物医学应用变得困难。ZnO NPs的毒性主要归因于活性氧（ROS）的产生。人们已经评估了不同的策略，如铁掺杂、聚合物涂层和抗氧化剂的外部供应，以尽量降低ZnO NPs的潜在毒性。褪黑素是松果体分泌的一种具有强大抗氧化特性的激素。已知褪黑素能保护细胞免受脂多糖等诱导ROS的外部因素的影响。在本研究中，使用C6神经胶质细胞评估了褪黑素对ZnO NPs介导的毒性的保护作用。测量了细胞毒性、线粒体膜电位和自由基形成，以研究褪黑素的作用。对用褪黑素和ZnO NPs孵育的小鼠脑片进行了抗氧化测定。研究结果表明，褪黑素预处理非但没有起到保护作用，反而增强了ZnO NPs的毒性。褪黑素增加了脑片中的抗氧化酶。
