Evaluation of biochemical markers in the blood plasma of rats exposed to chronic administration of a mixture of metal nanoparticles

Abstract

The aim of this study was to determine the effects of a specific mixture of metal nanoparticles (Ag, Cu, Fe and MnО2) orally administered to rats, on biochemical blood markers as indicators of chronic toxicity. Animals (Wistar line rats (n=20)) in experimental groups were given a solution of a mixture of metal salts or a mixture of nanoparticles with food for 90 days. On days 15, 30, 60 and 90 of the experiment, five rats from each group were anaesthetised with CO2 and decapitated, and blood samples were collected for biochemical studies and spectrophotometric measurement. The toxic effect of the chronic administration of the mixture at a dose of 4.0 mg/kg of body weight in white rats caused partial immunosuppression expressed as hypoproteinaemia, excessive formation of circulating immune complexes and acute phase serum mucoid proteins (P<0.05), and cytolytic damage to hepatocyte membranes. Levels of enzyme activity (AST, GGT, ALT and AP) were significantly elevated (P<0.05). It has been shown that the origin of the toxic effect is due to oxidative stress, which slowed lipoperoxidation along with the elevation of the level of carboxylated proteins, depleting the antioxidant defence resources of the organism, as seen by a decrease in the level of catalase and total antioxidant activity (P<0.05). No such effects were observed at the dose of 0.3 mg/kg as there were no significant negative impacts on the biomarkers. Based on this data, the biochemical markers studied may be suitable for use in pre-clinical in vivo toxicological assessment of metal nanoparticle-candidates for pharmaceuticals.