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 theirbiological effects and environmental fate. Silver nanoparticle, often referred to as nanosilver (n-Ag), maycause health problems because of its wide and ever growing use in many applications. n-Ag is used intreatments of wounds, disinfection of water and/or air and coatings textiles. n-Ag is shows toxic effectsonly when oxidized to silver ions (Ag+). There is a limited knowledge concerning environmental andhealth consequences of exposure to n-Ag. In the current study, we aimed to evaluate the potential ecotoxicityof 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 of 96 hr. Theconcentrations of n-Ag used in this study are not environmentally relevant but provide a model system toexamine its ecotoxicity.It was revealed that n-Ag imposes a severe lipid peroxidation (LPO/MDA) in Gammarus whole bodyextract. In addition, the activity of some antioxidant enzymes changed. Catalase (CAT) activity wasdecreased 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 has the potential to exert a strong oxidativestress, leading to altered physiological state.