Effects of Silver Nanoparticles on Fish Prochilodus lineatus: Oxidative Stress and Metabolic Responses

ALE A; ROSSI A; BACCHETTA C; DE LA TORRE FR; CAZENAVE J

Buenos Aires

Congreso; SETAC Latin America 11th Biennial Meeting; 2015

Silvernanoparticles (AgNPs) are present in a multitude of consumer and medical stuffdue to their antimicrobial properties. The increase in production and consumptionof silver-containing products leads to the release of AgNPs into the environment,therefore safety concerns have raised. The aim of the study was to analyzeoxidative stress responses and metabolic parameters in different tissuesofjuvenile Prochilodus lineatus exposed to AgNPs. Fish were exposed to the followingAgNPs concentrations (Colloidal nanosilver, Nanotek S.A.): 25 μg·L-1;2,5 μg·L-1(0.5 and 0.05 of 96-h LC50 value approximately) and 0 μg·L-1 (control)(2 fish per aquarium, with 5 replicates per treatment). The aquarium solutionswere renewed every 48 hours. After 5 and 15 days, liver, intestine, gills, brainand muscle samples were obtained from exposed and control fish. Oxidativestress biomarkers were evaluated in all organs through activities of antioxidantenzymes (catalase, glutathione S-transferase, glutathione reductase andglutathione peroxidase) and lipid peroxidation levels (LPO). Glycogen, proteinand lipid content were determined in liver and muscle. In the liver of fish exposedto 25 μg·L-1of AgNPs for 15 days, an induction of all antioxidant enzymes activities wasobserved in comparison with the control. It was accompanied by an increase inLPO levels which duplicated the control values. In regard to gills, all enzymesactivities decreased after 5 days of exposure at the lowest concentration ofAgNPs with respect to the control. On the contrary, the LPO levels decreasedafter 5 days at both concentrations. The enzyme activities measured inintestine and brain showed no differences among the treatments. However,the LPO levels in intestine decreased after 5 days of exposure at both concentrations.Regarding the metabolic responses, glycogen content showed a significantincrease in liver and muscle of fish exposed to 25 μg·L-1 ofAgNPs for 15 days, while protein concentration decreased only in muscle. Theresults confirmed that the presence of AgNPs, in short and subchronicexposures, cause oxidative stress mainly in the liver of fish. Furthermore,energy reserves were alteredunder the highest concentration and time of exposure. Thus it could threatenthe health of fish and generate vulnerability in cases of environmental stressconditions.