RESUMO
PROJECT: Beside its useful functions at very low concentrations, selenium including supplementary Se sources pose a potential toxicological risk. The toxicity of selenium species was tested in HaCaT cell culture and related nephrotoxicity in mice. PROCEDURE: The apoptotic shrinkage and necrotic expansion of cells were measured by time-lapse image microscopy. Acute nephrotoxicity was estimated upon administration of various selenium species to mice for two weeks. To confirm or to refute the accumulation of Se in the kidney and its potential chronic effect, Se concentration in kidney tissue and histopathlology were tested. RESULTS: The comparison of selenium species showed that organic lactomicroSe did not affect cell growth at 5ppm, but inorganic nanoSe severely hampered it at lower concentration (1ppm). The in vivo Se treatment (0.5, 5, 50ppm, corresponding to 4, 40 and 400µg/kg) was misleading as it did neither affect the outward appearance nor the weight of the kidney. Se accumulation was observed after selenate, selenite, SelPlex, selenite and nanoSe administration, while lactomicroSe caused no traceable accumulation. In vivo, ex vivo and in vitro experiments reflected this order of selenium toxicity: selenate>selenite>SelPlex=nanoSe>lactomicroSe. CONCLUSION: Within the tested species lactomicroSe was the only non-nephrotoxic selenium source recommended for nutritional Se supplementation.