Effects of silver nanoparticles administration on the liver of rainbow trout (Oncorhynchus mykiss): histological and biochemical studies

Despite increasing application of silver nanoparticles (NPs) in industry and consumer products, there is still little known about their potential toxicity, particularly to organisms in aquatic environments. Regarding fast development of the nanotechnology and its diverse applications, is very important having enough data on the probably its side effects on the aquatic body organs. Therefore, present investigations were taken on the effects of nanosilver administration on the liver's histology and biochemistry in rainbow trout. For this study, the silver nanoparticles were synthesized in a one-step reduction process in an aqueous solution. 60 O. mykiss were obtained from a local commercial hatchery. Fish were divided randomly into four groups. Experimental fish were exposed to concentration of 3, 300 and 1000 mg/L of nanosilver solution for eight weeks. At the end of experiments, blood samples were collected and biochemical analyses of sera were performed. Tissue samples were also taken and histological alterations of the liver were examined. In the hepatic structure of the treated fish with nanosilver; local congestion in the liver parenchyma, decreasing in the size and diameter of the hepatocytes and massive destination in the hepatic sinusoids sizes were seen In addition, the serum levels of total protein was decreased significantly (P<0.05) by elevation in the nanosilver concentration. On the other hands, AST and ALT levels in sera showed a significant increase in the nanosilver treated fish (P<0.05) when compared to control group. It is concluded that nanosilver treating could induces hepatic side effects and its administrating in the aquatic systems should be reconsidered.