Effects of 1,25 Dihydroxyvitamin D3 on Human Retinal Pigment Epithelial Cell Lines

Abstract

To assess the effects of 1,25 dihydroxyvitamin D3 (vitamin D3) either alone or under oxidative damage on human retinal pigment epithelium cell lines. The human retinal pigment epithelial cell lines were pretreated with hydrogen peroxide with different concentrations (100-1000μM) and durations (4, 12 and 24h) to determine the appropriate dose. A group of cells were treated with vitamin D3 alone, and another group of cells were co-treated with different concentrations of (10-100nM) vitamin D3 and hydrogen peroxide. Anti-cytotoxic, anti-apoptotic and anti-genotoxic effects of vitamin D3 on the hydrogen peroxide treated cell line were evaluated. In addition, mitochondrial membrane potentials of treated cell lines were measured. Vitamin D3 showed statistically significant anti-cytotoxic effects and increased cell viability in all concentrations (p < 0.001). It has also significantly decreased the intracellular ROS generation at concentrations between 10-60nM and increased intracellular reactive oxygen species in high doses over 90nM (p < 0.01). When apoptosis was evaluated, vitamin D3 caused statistically significant decrease in a dose-dependent manner (p < 0.001). In terms of DNA damage which was caused by oxidative stress, it was observed that vitamin D3 significantly reduced the damage in a dose-dependent manner (p < 0.001). At the doses of 10-50nM, vitamin D3 significantly decreased the mitochondrial membrane potential (p < 0.01). Our study suggests that 1,25 (OH)2 D3 is capable for alleviating the oxidative damage in ARPE cell lines. With these results, vitamin D is thought to be a therapeutic alternative for the prevention of age-related macular degeneration. This warrants further investigations.