São Carlos Institute of Chemistry, University of São Paulo, Av. Trabalhador São Carlense, 400, 13560-970 São Carlos, SP, Brazil.
Department of Ecology and Evolutionary Biology, Federal University of São Carlos, Rodovia Washington Luis, km 235, 13565-905 São Carlos, SP, Brazil.
Ecotoxicol Environ Saf. 2018 Oct 30;162:85-91. doi: 10.1016/j.ecoenv.2018.06.076. Epub 2018 Jun 30.
In this study, effects of parabens on antioxidant defenses and oxidative damages in gills and liver of Nile tilapia (Oreochromis niloticus) were evaluated. Adult Nile tilapia were exposed to methyl, ethyl, propyl, butyl and benzylparaben and a mixture of methyl and propylparaben for 6 and 12 days. The biomarkers analyzed were superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), total glutathione (GSH-t) and lipid peroxidation measured by malondialdehyde (MDA) content. Results indicated that exposure to parabens caused biochemical changes in gill and liver cells, which in turn modulated enzymatic and non-enzymatic antioxidants in Nile tilapia. SOD, GPx and GR activity significantly increased in gills and liver after exposure to most parabens. CAT activity had little (liver) or no alteration (gills) in this fish species after treatment with parabens. GSH-t content in liver decreased after 6 days of exposure to parabens, but after 12 days, GSH-t levels increased in liver in all treatments, indicating an antioxidant adaptation to exposure to sublethal doses of parabens. Regarding the MDA levels, no alterations were observed in gills compared to control and in liver the MDA content was reduced after 12d of exposure to ethylparaben, butylparaben and paraben mixture, indicating no lipid peroxidation in the analyzed tissues. Our results demonstrate parabens-induced adaptive responses in fish, which were important in the protection against oxidative damages.
本研究评价了对羟基苯甲酸酯类物质对尼罗罗非鱼（Oreochromis niloticus）鳃和肝脏抗氧化防御系统和氧化损伤的影响。成年尼罗罗非鱼分别暴露于甲基对羟基苯甲酸酯、乙基对羟基苯甲酸酯、丙基对羟基苯甲酸酯、丁基对羟基苯甲酸酯和苄基对羟基苯甲酸酯以及混合的甲基对羟基苯甲酸酯和丙基对羟基苯甲酸酯中 6 天和 12 天。分析的生物标志物有超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GPx）、谷胱甘肽还原酶（GR）、总谷胱甘肽（GSH-t）和丙二醛（MDA）含量来衡量的脂质过氧化作用。结果表明，对羟基苯甲酸酯类物质的暴露导致了尼罗罗非鱼鳃和肝脏细胞的生化变化，进而调节了尼罗罗非鱼的酶和非酶抗氧化剂。暴露于大多数对羟基苯甲酸酯类物质后，尼罗罗非鱼鳃和肝脏中的 SOD、GPx 和 GR 活性显著增加。在这种鱼类中，CAT 活性在接触对羟基苯甲酸酯类物质后几乎没有（肝脏）或没有变化（鳃）。暴露于对羟基苯甲酸酯类物质 6 天后，肝脏中的 GSH-t 含量下降，但 12 天后，所有处理组的肝脏中 GSH-t 水平均升高，表明肝脏对接触亚致死剂量的对羟基苯甲酸酯类物质有抗氧化适应能力。关于 MDA 水平，与对照组相比，鳃中没有变化，而在暴露于乙基对羟基苯甲酸酯、丁基对羟基苯甲酸酯和对羟基苯甲酸酯混合物 12 天后，肝脏中的 MDA 含量降低，表明分析组织中没有脂质过氧化作用。我们的研究结果表明，对羟基苯甲酸酯类物质诱导鱼类产生适应性反应，这对于防止氧化损伤很重要。
