Abstract
Purpose :
UVA irradiation causes the production of reactive oxygen species (ROS), mitochondrial dysfunction and DNA damage in RPE cells. Fucoxanthin, a marine carotenoid extracted from brown seaweed, is a bioactive compound with anti-inflammatory and antioxidant properties. Fucoxanthin was previously shown to significantly inhibit ROS generation and protect RPE cells from H2O2-induced oxidative stress cell damage. This study aims to investigate the protective effects of fucoxanthin against UVA-irradiated differentiated ARPE-19 cells.
Methods :
ARPE-19 cells were differentiated to a physiologically relevant RPE-like phenotype using α-MEM low serum-containing medium, supplemented with 1% N1, 0.25 mg/ml taurine, 20 ng/ml hydrocortisone, 0.013 ng/ml triiodo-thyronine and 10 nM nicotinamide for 4 weeks. Gene expression of RPE markers RPE65, RLBP1, and RDH5 was investigated using real-time RT-PCR. To assess the impact of fucoxanthin-induced mitigation of UV cytotoxicity, the cells were pretreated with 1.25μM, 2.5μM and 5μM fucoxanthin for 3 days prior to UV treatment. Subsequently, fucoxanthin-treated cells were exposed to UVA at 40 J/cm2 for 40 min, followed by the MTT assay. Intracellular ROS production and SOD activity were assessed by measuring the oxidative conversion of DCFH-DA to fluorescent DCF using a fluorospectrophotometer and colorimetric SOD activity assay, respectively.
Results :
Differentiated ARPE-19 exhibited cobblestone morphology and heavy pigmentation, compared with the fibroblast-like morphology and lack of pigmentation in the undifferentiated ARPE-19. RPE-specific markers RPE65, RLBP1, and RDH5 in differentiated ARPE-19 were upregulated compared to undifferentiated ARPE-19. After UVA exposure, the cell metabolic activity of ARPE-19 cells was decreased to 35%, while cells pretreated with fucoxanthin at concentrations of 1.25 μM, 2.5 μM and 5μM for 72h showed significantly increased metabolic activity to 50.7%, 58.7% and 81.1% (p<0.05) respectively, compared with the untreated group. Pretreatment with fucoxanthin similarly decreased intracellular ROS production compared with the untreated group.
Conclusions :
The results demonstrate that fucoxanthin has a cytoprotective effect and mitigates UVA-induced damage in differentiated ARPE-19 cells. The findings may lead to an additional strategy for AMD prevention and development of new therapeutic agents.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.