Evaluation of Effects of Selenium Nanoparticles as an Occupational and Environmental Chemical Hazard on Cellular Bioenergetic Processes

Abstract

Introduction: High-volume manufacturing of selenium and a widespread use of its compounds pose potential risks to human health. Certain copper production processes emit selenium-containing nanoparticles. Objective: To assess health effects of selenium oxide nanoparticles as an industrial and environmental toxicant. Materials and methods: Selenium oxide nanoparticles (SeO NPs) were obtained by laser ablation. Their toxicity was studied both in vitro on human lung-derived embryonic fibroblasts (FLEH-104 cell line) by assaying adenosine triphosphate (ATP) bioluminescence and the rate of oxygen consumption, and in vivo on outbred albino rats by analyzing ultrastructural changes in tissues using electron microscopy, measuring succinate dehydrogenase activity of blood lymphocytes, and conducting a blood-based metabolomic test. Results: The in vitro experiment showed a decrease in ATP bioluminescence by 75.9 % and in the oxygen consumption rate of cells by 79.8 % in the incubation medium with 100 μg/mL concentration of SeO NPs. In the in vivo experiment, succinate dehydrogenase activity of blood lymphocytes decreased inversely with the increasing dose by 10.12 %, 14.0 %, 15.9 % compared to the control animals in the SeO NPs 0.1, SeO NPs 0.5, and SeO NPs 1 exposure groups, respectively. The study of ultrastructural changes in liver tissue showed a smaller number of normal mitochondria (7.78 % less in the SeO NP 1 group) compared to the controls while the metabolomic test revealed decreased acylcarnitines and increased lysophosphatidylinositols following the exposure to SeO NPs (p > 0.05). Conclusion: The results of our in vitro and in vivo studies showed adverse effects of SeO NPs on bioenergetics processes in cells involving at least two mechanisms: disruption of mitochondrial β-oxidation of fatty acid and inactivation of succinate dehydrogenase. The fundamental role of the latter in the mitochondrial electron transport chain makes its vitally important for most multicellular organisms. Our findings can serve as a rationale for assessing selenium-containing nanoparticles as a chemical hazard and searching for approaches to managing their health risks.