LIPID PEROXIDATION AND PROTEIN OXIDATION INDUCED BY DIFFERENT NANOPARTICLES IN ZEBRAFISH ORGANS

The protein oxidation and the lipid peroxidation induced by the presence of five different kinds of nanoparticles were determined in different tissues of zebrafish (Danio rerio). Both oxidative stress markers showed to be dose-dependent. At 1 ppm nanoparticle concentration, the five assayed nanoparticles showed higher protein oxidation than the control experiments. Europium-doped yttrium oxide (Y sub(2)O sub(3):Eu) and carboxylated multi-walled carbon nanotubes (MWCNT-COOH) showed the highest effect, especially in ovaries, testicles and brain, reaching carbonyl content in proteins up to 4-times higher than control, while bismuth germanate (BGO) and MWCNT-COOH nanoparticles induced lipid peroxidation in all analyzed tissues, reaching values up to two-times higher than those from non-exposed control fish. BGO and silver nanoparticles (AgNP) showed less oxidative effect; nevertheless, the protein oxidation still accounted for up to 3-times the control fish values. At 1 ppm, the protein oxidation induced by some nanoparticles reached the values obtained in the experiments with 100 mu M H sub(2)O sub(2). On the other hand, no significant differences were found in gene expression of oxidative stress markers after 48 h treatment. The results from this work clearly indicate that exposure to those nanoparticles may cause significant protein and lipid oxidative damage.