Effect of long-time exposure of green and chemical synthesized silver nanoparticles on antioxidant system and immune action of Asian seabass (Lates calcarifer)

Abstract The unique behavior of silver nanoparticles (AgNPs) led to their increasing use in a wide range of products and high discharge of these particles in the aquatic ecosystem. Regarding little information about the toxicity of AgNPs in the aquatic environment, the prediction of possible environmental hazards is the hot topic of current research studies. This study aimed to investigate the effects of long-time exposure of Asian seabass (Lates calcarifer)‎ to green (using brown macroalga extract) and chemical synthesized ‎AgNPs on oxidant/antioxidant and immunological responses. The LC50 of both synthesized AgNPs was determined after 96 h (LC50 for green synthesize AgNPs= 18.27 mg/l and for chemical synthesize AgNPs= 1.32 mg/l). Fish were exposed to green and chemical synthesized AgNPs concentrations of 0% LC50 (control), 5% LC50 , 10% LC50, and 25% LC50 for 60 days. Fish were sampled at 1, 30, and 60 days after exposure. The liver tissue of fish samples was isolated and homogenized and then the activity of catalase (CAT), superoxide dismutase (SOD) and glutathione (GSH), and malondialdehyde (MDA) was determined. The complement pathway activity (ACP), total immunoglobulin (Ig), total protein, albumin (ALB) ‎concentration, and globulin (GLO) were measured in fish blood samples. The results showed that green synthesized ‎AgNPs first ‎increased the activity of the antioxidant system and then significantly reduced its activity. However, after exposure to chemical synthesized AgNPs, ‎the activity of the antioxidant system showed a significant decrease. Both green and ‎chemical synthesized AgNP exposure caused an increase in proinflammatory activities and ‎immune proteins, and these activities were more ‎pronounced after exposure to green synthesized AgNP.