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

The extensive use of nanoparticles in a variety of applications has raised great concerns regarding their biological effects and environmental fate. Silver nanoparticle، often referred to as nanosilver (n-Ag)، may be cause health problems because of its wide and ever growing use in many applications. n-Ag is used in treatments of wounds، disinfection of water and/or air and coatings textiles. n-Ag is shows toxic effects only when oxidized to silver ions (Ag+). There is a limited knowledge concerning environmental and health consequences of exposure to n-Ag. In the current study، we aimed to evaluate the potential ecotoxicity of n-Ag for freshwater crustacean model organism، Gammarus pseudosyriacus. Three low concentration solutions of n-Ag (2. 5، 5 and 7. 5 ppm) were used over a period 96 hr. The concentrations of n-Ag used in this study are not environmentally relevant but provide a model system to examine its ecotoxicity. It was revealed that n-Ag imposes a severe lipid peroxidation (LPO/MDA) in Gammarus whole body extract. In addition، the activity of some antioxidant enzymes changed. Catalase (CAT) activity was decreased and glutathione peroxidase (GPx) activity significantly increased. Acetylcholinesterase (AChE) activity was also markedly decreased. An abnormal vigorous movement was observed among animals. Briefly، n-Ag was found highly toxic to aquatic organisms and with the potential to exert a strong oxidative stress، leading to altered physiological state.