Evaluation of oxidative stress biomarkers and acetylcholinesterase activity in Gammarus pseudosyriacus exposed to nanosilver

Abstract

The extensive use of nanoparticles in a variety of applications has raised great concerns regarding their<br />biological effects and environmental fate. Silver nanoparticle, often referred to as nanosilver (n-Ag), may<br />cause health problems because of its wide and ever growing use in many applications. n-Ag is used in<br />treatments of wounds, disinfection of water and/or air and coatings textiles. n-Ag is shows toxic effects<br />only when oxidized to silver ions (Ag+). There is a limited knowledge concerning environmental and<br />health consequences of exposure to n-Ag. In the current study, we aimed to evaluate the potential ecotoxicity<br />of n-Ag for freshwater crustacean model organism, Gammarus pseudosyriacus.<br />Three low concentration solutions of n-Ag (2.5, 5 and 7.5 ppm) were used over a period of 96 hr. The<br />concentrations of n-Ag used in this study are not environmentally relevant but provide a model system to<br />examine its ecotoxicity.<br />It was revealed that n-Ag imposes a severe lipid peroxidation (LPO/MDA) in Gammarus whole body<br />extract. In addition, the activity of some antioxidant enzymes changed. Catalase (CAT) activity was<br />decreased and glutathione peroxidase (GPx) activity significantly increased. Acetylcholinesterase (AChE)<br />activity was also markedly decreased. An abnormal vigorous movement was observed among animals.<br />Briefly, n-Ag was found highly toxic to aquatic organisms and has the potential to exert a strong oxidative<br />stress, leading to altered physiological state.