Increased Cytotoxicity of Vanadium to CHO-K1 Cells in the Presence of Inorganic Selenium

The effect of selenium applied as sodium selenite (Na2SeO3) on the cytotoxicity of vanadyl sulphate (VOSO4) was examined using CHO-K1 cells. From the resazurin-based assay, it appears that Na2SeO3 at low doses (0.5 and 1 mu M) can enhance 100 mu M VOSO4-induced cell damage. The two-way ANOVA analysis revealed that the increased cell damage was a consequence of a synergistic interaction of 0.5 mu M Na2SeO3 with VOSO4 and 1 mu M Na2SeO3 with VOSO4. Observations performed with a phase-contrast microscope showed most cells to be rounded upon treatment with VOSO4 alone. In turn, a majority of cells co-treated with VOSO4 and 1 mu M Na2SeO3 were elongated, and exhibited cytoplasmic vacuolization. These results warn of the potential contribution of inorganic selenium to vanadium-induced toxicity.