Protective Effect Of Lycium Barbarum Extract On Human Retinal Pigment Epithelial Cells

Purpose:Human retinal pigment epithelial?RPE?cells are an important part of regulating and maintaining retinal health and homeostasis in human eyes.Oxidative stress-induced damage to RPE cells has been suggested to be an important factor in the pathogenesis of age-related macular degeneration.Age-related macular degeneration is one of the major factors of vision loss and even blindness in the elderly population worldwide.Lycium barbarum,a Solanaceae plant,has been shown to have particularly pronounced antioxidative biological activity.In human retinal pigment epithelial cells,oxidative damage caused by H₂O₂ can induce apoptosis and up-regulation of inflammatory cytokines.The purpose of this study was to investigate whether wolfberry extract polysaccharides and carotenoids have protective effects.METHODS:1)The oxidative damage model was constructed with different concentrations of H₂O₂?200?mol/L,300?mol/L,500?mol/L,and 800?mol/L?;the oxidative damage model was established by screening the LD50;2)The sulforhodamine B?SRB?method was used to detect the cell toxicity of Lycium barbarum polysaccharides and carotenoids on ARPE-19 cells,and to select the optimal experimental concentration;3)The effects of lycium barbarum polysaccharides and carotenoids on H₂O₂-induced cell viability were determined by CCK-8method;4)Flow cytometry was used to detect the effect of LBP and carotenoids on the incidence of apoptosis induced by H₂O₂;5)MDA content was detected with MDA kit;6)A DCFH-DA fluorescence probe and flow cytometry were used to detect the release of ROS in cells;7)The secretion of cytokines TNF-?and IL-1?were detected using ELISA kit.Results:1)The experimental results showed that when the H₂O₂ treatment concentration was300?mol/L,the survival rate and the mortality ratio of human retinal pigment epithelial cells were equal to about 1,so this concentration was chosen as the optimal concentration to establish the oxidative damage model.When the concentrations of lycium barbarum extract LBP and carotenoids were in the range of 10^-5-10^-2 mg/mL,the cell proliferation rate was not statistically different from that of the untreated cells in the control group.2)When the lycium barbarum polysaccharides extract and carotenoids at a concentration of 10^-1 mg/mL the cell proliferation rate was statistically different from that of the untreated cells in the control group.3)The cck-8test showed after adding carotenoids that the viability of cells was higher than that in the control group treated with H₂O₂.4)The results of flow cytometry showed that pretreatment with the extracts of Lycium barbarum polysaccharides and carotenoids downregulated the apoptotic rate when compared to cells treated with only 300?mol/L H₂O₂;5)MDA test results showed that the content of MDA in H₂O₂ oxidative damage treatment group showed an increasing trend compared with that of normal control group,and the content of MDA in the extracts of Lycium barbarum polysaccharides and carotenoids were reduced;6)The results of flow cytometry detection of reactive oxygen species showed that polysaccharides and carotenoids reduced the release of ROS;7)ELISA test results showed that polysaccharides and carotenoid inhibited the secretion of TNF-?and IL-1?.Conclusion:The extracts of Lycium barbarum polysaccharides and carotenoids have protective effects on H₂O₂ and ROS-induced oxidative damage and inflammation.This study suggests that extracts of Lycium barbarum polysaccharides and carotenoids can protect the human retinal pigment epithelial cells and achieve the purpose of brightening.