About combination of positive and negative outcomes of a subchronic exposure of rats to selenium oxide nanoparticles

Introduction. Occupational contact with selenium and its compounds, including nanoscale forms, occurs in the glass production, rubber industry, metallurgy (metallurgical processes of copper sludge processing, copper pyrite roasting, manganese, selenium and tellurium production). There are scarce data on the toxicity of selenium nanoparticles. Material and methods. Stable suspensions of nanoparticles or deionized water (control group) were administered to male rats 3 times a week for 6 weeks. A single dose of selenium oxide nanoparticles was 0.2 or 1 or 2 mg/kg of body weight). The condition of the animal organism was assessed with a number of indicators of toxic action at the end of the experiment. The statistical significance of intergroup differences was assessed by Student's t-test. Results. Activity of succinate dehydrogenase in blood lymphocytes reflecting the intensity of energy processes in the organism was decreased. The number of eosinophils in smears-imprints of parenchymal organs and mesenteric lymph nodes increased, indicating the ability of selenium nanooxide to trigger signaling cascades in immunocompetent cells. The number of degenerated cells in the proximal and distal tubules in smears of the kidneys was increased. A tendency to a decrease in all hemodynamics parameters was found. A change in the QT duration, together with an increase in the amplitude of the T wave, probably indicates a violation of the processes of myocardial repolarization. The coefficient of fragmentation of genomic DNA in nucleated blood cells decreased. Limitations. The research was limited to the study of indicators of toxic action in only one study using a limited dose range. Conclusion. An ambiguous effect of selenium oxide nanoparticles on rats was found. Along with negative impact of nanoparticles we have demonstrated, for the first time, some beneficial outcomes, in particular, genome -protective action which is in a striking contrast with the genotoxicity of all elemental and element-oxide nanoparticles previously studied in our laboratory.