ABSTRACT
Background: This study was initiated to improve our understanding of the health and environmental impact of silver nanoparticles [Ag-np]
Objectives: The purpose of the study is application and direct effects of silver nanoparticles on Zebra fish [Danio rerio]
Methods: After characterizing the AgNPs using TEM, EDX, UV-Vis Spectroscopy, XRF and SEM methods, their effects on some vital tissues have been tested successfully in vitro. In this study, 540 fish [2+/-0.05 g] were randomly divided into 9 groups in triplicate for acute tests [0,10, 50, 100,200,400, 600, 800 and 1000 mg/kgfood]. After short term [96h], chronic toxicity tests were evaluated using under lethal concentration [100, 400, 600 and 800 mg/kgfood] fed with experimental diet for 8 weeks. Fish in groups 1 to 4 were fed by food supplemented with 100, 400, 600 and 800 mg/kg food, respectively. Group 5 was fed with basal food without supplementation. After histopathology, heavy metals were measured by spectrum photometry reveal
Results: According to the results of acute tests, the 96h LC50 values in 24, 48, 72 and 96h were 804.601, 486.637, 323.696 and 195.208 mg/kgfood AgNPs for the Zebra fishes respectively. According to the results of chronic toxicity tests, fed via oral administration of AgNPs produced significant histopathological effects. Also, the most important histopathological effects of AgNPs were observed in the liver [vasculature and exposure, degeneration of some hepatocytes], intestine [increase in the submucosa layer, narrowing of the intestinal lumen and reduced intestinal absorption], gills [clubbing of gill secondary lamaleas, hyperplasia, hyperemia and shortening of the primary lamaleas gills] and kidney [degeneration, high increase in interstitial cells and dilatation of Bowman's space of glomeruli], respectively. The greatest bioaccumulation of silver occurred in the liver, gills and muscle offish respectively [p<0.05]
Conclusions: The release of untreated nanoparticle waste to the environment should be restricted for the well-being of human and aquatic species
Subject(s)
Animals , Silver/pharmacology , Zebrafish , Animal FeedABSTRACT
Outbreaks causing mass mortalities have been observed in the golden grey mullet [Liza auratus] population in southern coastal area of the Caspian Sea since 2002. The clinical signs include neurological abnormalities, such as erratic swimming behavior, spiral swimming, belly-up at rest and over inflation of the swim bladder. Three hundred and twelve samples of moribund fish with sizes that ranged from 15-26 cm showing abdominal enlargement were collected from 2006-2008. No pathogenic bacteria and parasite were found. The observed histopathological changes in 29 fish were necrosis and vacuolation of the brain, optic nerve and retina. Cytopathological effects of nodavirus characterized by vacuolation were observed in the SSN-1 cell line at 25°C, 5 d after inoculation with the filtered supernatant of the brain and eye of four affected fish. The recovered virus from cell line exhibited 10[4] TCID[50] per mL when titrated. Indirect immunoflorescent antibody test showed nodavirus antigens in the retina and positive-CPE SSN-1 cells. Also, a RT-PCR product of approximately 289 bp was amplified from the brain and retina of the 23 samples, including the SSN-1 positive samples. This is the first report of the isolation and characterization of nodavirus from golden grey mullet from the Caspian Sea and, therefore, possible infections in other valuable species of the Caspian Sea warrant further studies