Abstract
Purpose :
Diabetic retinopathy is associated with carotenoid metabolism in humans, understanding its underlying mechanism of pathogenesis at the very early stage of diabetes is critical to developing preventive strategies focused on diet and nutrition. In this study, the effect of β-carotene on the growth of human retinal pigment epithelial cells (ARPE-19) cells was evaluated and the effects of β-carotene on redox state and the regulation of cytokine secretion were investigated.
Methods :
ARPE-19 cells were treated with different concentrations ofβ- carotenoids, the cell viability was determined by MTT assay. Fatty acid composition was determined by GC chromatogram. Lipoxin LXA4, a Fatty Acid Metabolite, was quantified by ELISA method. Reactive oxygen species generation was evaluated by Fluorescent probe DCFH-DA. MDA and antioxidant enzyme such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities were measured. TNF-α, IL-4 and IL-6 secretions were evaluated by ELISA.
Results :
MTT showed that β- carotenoids concentration in the range of 10-200 μM did not affect the growth of the ARPE-19 cells, but when the concentration exceeded 250 μM the survival rate began to decrease significantly. GC chromatogram showed the proportion of intracellular fatty acid composition was significantly changed after β- carotenoids treatment (100 μM, 24hr). The exogenous β- carotenoids resulted in the accumulation of fatty acids. β- carotenoids treatment could affect the expression of LXA4 in ARPE-19 cells significantly (100 μM, 24hr). The expression of LXA4 was decreased by 23.03%. β- carotenoids treatment(100 μM, 24hr) on ARPE-19 cells caused significant increased ROS generation, MDA accumulation, CAT activity and GSH-Px activity that correlated with corresponding slight decrease in SOD activity(P>0.05). ELISA results showed that β- carotenoids treatment (100 μM, 24hr) significantly reduced IL-4 secretion, but TNF-α and IL-6 secretion were not inhibited.
Conclusions :
These results suggest that exogenous β- carotenoids can protect ARPE-19 cells. β- carotenoid has a safe dose concentration on ARPE-19 cells. The exogenous β- carotenoids resulted in accumulation of intracellular LA and enhanced metabolism of long-chain fatty acids in the downstream. β- carotenoids could alleviate oxidative stress and inflammation. Further study should be working on high glucose induced cell models.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.