Protective Effect of Alpha-Tocopherol Isomer from Vitamin E against the H2O2Induced Toxicity on Dental Pulp Cells

The aim of this study was to evaluate the protective effects of different concentrations of vitamin E alpha-tocopherol ( α -T) isomer against the toxicity of hydrogen peroxide (H 2 O 2 ) on dental pulp cells. The cells (MDPC-23) were seeded in 96-well plates for 72 hours, followed by treatment with 1, 3, 5, or 10 mM α -T for 60 minutes. They were then exposed or not to H 2 O 2 for 30 minutes. In positive and negative control groups, the cells were exposed to culture medium with or without H 2 O 2 (0.018%), respectively. Cell viability was evaluated by MTT assay (Kruskal-Wallis and Mann-Whitney tests; α = 5%). Significant reduction of cell viability (58.5%) was observed in positive control compared with the negative control. Cells pretreated with α -T at 1, 3, 5, and 10 mM concentrations and exposed to H 2 O 2 had their viability decreased by 43%, 32%, 25%, and 27.5%, respectively. These values were significantly lower than those observed in the positive control, thereby showing a protective effect of α -T against the H 2 O 2 toxicity. Overall, the vitamin E α -T isomer protected the immortalized MDPC-23 pulp cells against the toxic effects of H 2 O 2 . The most effective cell protection was provided by 5 and 10 mM concentrations of α -T.