Abstract
Purpose: :
PURPOSE: Age related macular degeneration (AMD) is the leading cause of blindness in the western world. Oxidative stress plays an important role in the etiopathogenesis of AMD. Lutein (LUT) and zeaxanthin (ZEA), major components in macular pigment, prevent oxidative damage and slow the rate of progression of AMD. In this study, we investigated whether LUT, ZEA, protect retinal pigment epithelium (RPE) from oxidative stress.
Methods: :
3000 cultured human retinal pigment epithelial cells (ARPE-19) were plated in 72-well plate and after 24hrs, cells were exposed to four different concentrations of Lutein (4,2,1 and 0.5 µg/ml) and Zeaxanthin (0.8,0.4,0.2 and 0.1µg/ml ). After 24 hours incubation, cells were subjected to oxidative stress induced with hydrogen peroxide. Cultures containing saline solution and trichloromethane served as controls. Cell cytotoxicity and cell viability were assessed using the Neutral red (NR) assay and WST assay. Cell structural morphological changes were recorded using phase contrast bright field microscopy.
Results: :
Using the WST assay, a dose dependent cytoprotective effect was observed in ARPE-19 cells exposed to hydrogen peroxide after pretreatment with both Lutein and Zexanthin. (Cell viability as a percentage of control were 81.3, 81.1, 88.8 % at 4, 2, and 1 µg/ml, respectively of Lutein). This effect was reversed after cells were incubated with higher concentrations of Lutein (4 µg/ml) and Zexanthin (0.2 and 0.1 µg/ml). Results were validated by analysis of structural morphological changes noted using phase contrast bright field microscopy.
Conclusions: :
These results show that Lutein and Xeaxanthin play an important role in preventing oxidative stress induced RPE cell loss in in-vitro conditions.
Keywords: antioxidants • oxidation/oxidative or free radical damage • retinal pigment epithelium