Protective Effect Of Luteolin On Sodium Iodate-induced Retinal Pigment Epithelial Cells And Retinal Damage

ObjectiveTo investigate the protective effect of luteolin on sodium iodate-induced RPE cells and retinal damage.MethodsIn vitro,ARPE-19 cells were selected and the cells were first divided into control group,luteolin concentration gradient group and control group,sodium iodate model group,luteolin concentration gradient treatment group,MTT was used to detect the viability of each group.Then the cells were divided into control group,sodium iodate model group,luteolin treatment group(50?mol·L^-1),Hoechst33342 staining and flow cytometry were used to detect apoptosis,Western blotting was used to detect the relative expression of Bcl-2,Bax,cleaved caspase-3,and HMGB1,TLR4 and NF-?B.In vivo,30 C57BL/6J male mice were randomly divided into control group,sodium iodate model group and luteolin treatment group.After 1 week of luteolin treatment in the luteolin treatment group,the sodium iodate model group and the treatment group were given sodium iodate in the tail vein,and the luteolin treatment group continued to be administered as before for 4 weeks.OCT measurement measured retinal thickness,HE staining was used to observe morphological changes and count the number of drusen,ERG was used to detect the amplitude of a wave and b wave and their latency.ResultsIn vitro,MTT showed that compared with the control group,the optical density of luteolin concentration gradient group with the concentration of luteolin alone?10-100??mol·L^-1 had no significant change?P>0.05?,and the optical density of the concentration of luteolin 200?mol·L^-1 was lower?P<0.05?.The optical density of the sodium iodate model group was lower than that of the control group?P<0.05?,and the optical density of the luteolin concentration gradient treatment group was higher than that of the sodium iodate model group?P<0.05?.Hoechst33342 staining showed that the apoptosis rate of the sodium iodate model group was higher than that of the control group?P<0.05?,and the apoptosis rate of the luteolin treatment group was lower than that of the sodium iodate model group?P<0.05?.Flow cytometry showed that compared with the control group,the apoptosis rate of sodium iodate model group was higher?P<0.05?,and the apoptosis rate of luteolin treatment group was lower than that of sodium iodate model group?P<0.05?.Western blotting showed that the relative expression of Bcl-2 in the sodium iodate model group was lower than that in the control group?P<0.05?.The relative expression of Bcl-2 in the luteolin treatment group was higher than that in the sodium iodate model group?P<0.05?.The relative expressions of Bax,cleaved caspase-3 and HMGB1,TLR4 and NF-?B were higher than those in the control group?P<0.05?,the relative expressions of Bax,cleaved caspase-3 and HMGB1,TLR4 and NF-?B in the luteolin treatment group were lower than those in the sodium iodide model group?P<0.05?.In vivo,OCT showed that the structure of each layer of the control group was neatly arranged.Compared with the sodium iodate model group,the high reflection point of the RPE layer in the luteolin treatment group was reduced,the relative thickness of INL and ONL were increased?P<0.05?,and the relative thickness of the total retina was increased?P<0.05?.HE staining showed that compared with the sodium iodate model group,the density of INL and ONL of the luteolin treatment group was higher?P<0.05?,the continuity of the RPE layer was increased,and the number of drusen was decreased?P<0.05?,ERG showed that the amplitudes of a wave and b wave and their latency were lower in the sodium iodate model group than in the control group?P<0.05?,the amplitudes of a wave and b wave and their latency in the luteolin treatment group were higher than those of the sodium iodate model group?P<0.05?.ConclusionsLuteolin inhibits sodium iodate-induced apoptosis in RPE cells and reduces retinal damage by attenuating HMGB1/TLR4/NF-?B-mediated inflammation.