resumo
This in vitro study investigates the impact of silicacoated magnetite particles (Fe3O4@SiO2/SiDTC, hereafter called IONP; 2.5 mg L-1) and its interference with coexposure to persistent contaminant (mercury, Hg; 50 mu g L-1) during 0, 2, 4, 8, 16, 24, 48, and 72 h on European eel (Anguilla anguilla) brain and evaluates the significance of the glutathione (GSH) redox system in this context. The extent of damage (membrane lipid peroxidation, measured as thiobarbituric acid reactive substances, TBARS; protein oxidation, measured as reactive carbonyls, RCs) decreased with increasing period of exposure to IONP or IONP + Hg which was accompanied with differential responses of glutathione redox system major components (glutathione reductase, GR; glutathione peroxidase, GPX; total GSH, TGSH). The occurrence of antagonism between IONP and Hg impacts was evident at late hour (72 h), where significantly decreased TBARS and RC levels and GR and glutathione sulfotransferase (GST) activity imply the positive effect of IONP + Hg concomitant exposure against Hg-accrued negative impacts [vs. early (2 h) hour of exposure]. A period of exposuredependent IONP alone and IONP + Hg joint exposureaccrued impact was perceptible. Additionally, increased susceptibility of the GSH redox system to increased period of exposure to Hg was depicted, where insufficiency of elevated GR for the maintenance of TGSH required for membrane lipid and cellular protein protection was displayed. Overall, a finetuning among brain glutathione redox system components was revealed controlling IONP + Hg interactive impacts successfully.
palavras-chave
IRON-OXIDE NANOPARTICLES; LIPID-PEROXIDATION; METHYLMERCURY EXPOSURE; CELLS; CYTOTOXICITY; ENVIRONMENT; DEPLETION; RESPONSES; TOXICITY; RECOVERY
categoria
Environmental Sciences & Ecology
autores
Anjum, NA; Srikanth, K; Mohmood, I; Sayeed, I; Trindade, T; Duarte, AC; Pereira, E; Ahmad, I
nossos autores
agradecimentos
The authors are grateful to the Portuguese Foundation for Science and Technology (FCT) for Post-doctoral grants to NAA (SFRH/BPD/84671/2012) and KS (SFRH/BPD/79490/2011) and PhD grant to IM (SFRH/BD/74410/2010) and to the Aveiro University Research Institute/CESAM. The authors are also indebted to Daniela S. Tavares, University of Aveiro, Portugal for providing IONPs for the current bioexperiments.