Protective effects of Lycium barbarum polysaccharides on retinal photoreceptor cells induced by exposure to N-methyl-D-aspartate
Objective To investigate the protective effects of Lycium barbarum polysaccharide(LBP)on retinal photoreceptor cell damage caused by exposure to N-methyl-D-aspartate(NMDA)and its possible mechanism.Methods The experiment was divided into normal group,model group,control group and experimental-L,-M,-H groups.The experimental-L,-M,-H groups were given 0.01,0.50 and 2.00 mg·mL-1 LBP,respectively,while the control group was given 10 μamol·L-1 MK-801 solution.The normal and model groups were given the same volume of complete culture medium.Cell counting kit-8(CCK-8)was used to measure cell survival.Flow cytometry was used to measured cell apoptosis.Calcium imaging was used to measure changes in intracellular calcium concentration.Western blot was used to determine protein levels of B-cell lymphoma-2(Bcl-2)and Bcl-2 associated X protein(Bax).Results The cell survival rates of experimental-M,control,model and normal groups were(85.92±6.21)%,(72.33±5.45)%,(37.92±2.31)%and(97.12±5.11)%;the apoptosis rates were(13.80±0.52)%,(15.22±0.51)%,(38.10±0.67)%and(5.34±0.46)%;the intracellular calcium relative concentration after NMDA was added 30 s were 3.00±0.37,4.65±0.24,27.24±0.96 and 1.02±0.32;the relative expression levels of Bel-2 protein were 0.80±0.05,0.78±0.02,0.30±0.04 and 1.00±0.05;the relative expression levels of Bax protein were 1.57±0.04,1.91±0.05,5.18±0.06 and 1.00±0.04,respectively.Compared with the model group,the above-mentioned indexes in the experimental-M and control groups had statistical significance(all P<0.05).Conclusion LBP could preclude the damage of retinal photoreceptor cells induced by exposure to NMDA,the possible mechanisms are related to inhibit the internal flow of calcium,and decrease the Bax expression and increase Bel-2 expression at protein level.