The effect of vitamin E and selenium combination in repairing fluoride-induced DNA damage to NRK-52E cells.

Prolonged and excessive fluoride exposure can lead to fluorosis. The kidney is one of the organs that are injured mostly due to fluoride-induced damage. Fluoride can induce DNA damage at cytotoxic concentrations. This study aims to determine the extent of NaF-induced DNA damage and to investigate the effect of vitamin E and selenium combination (ES) in preventing and repairing this damage. For this purpose, we administered different combinations of NaF and ES to NRK-52E cells and determined the effective concentrations of ES and the NaF IC50 values associated with different incubation times (3, 12, and 24 h) by using the MTT assay. The determined quantities of NaF IC50 in association with time and the NaF IC50 + ES combination were administered to the cells. The extent of DNA damage was determined with the comet assay and the expression levels of the Ku70/80 and PARP-1 genes were determined with the RT-qPCR method. DNA damage significantly increased in all experimental groups compared to the control group (p < 0.05). It was found out that the NaF and ES combination statistically reduced the DNA damage compared to the damage observed in the NaF-treated groups (p < 0.05). Treatment of the ES combination significantly increased the expressions of Ku70 and Ku80 genes involved in DNA repair (p < 0.05). We concluded that vitamin E and selenium can potentially be effective in the repair of fluoride-induced DNA damage based on the results of this in vitro study. Our results may shed light on the prevention of DNA damage associated with fluorosis.