Protective effect of anthocyanidin extracts on light-induced retinal functional and structural damage in rat / 中华实验眼科杂志

ABSTRACT

Background Light leads to the damage of retinal function and structure by promoting the reproduction of radicals and lipid peroxides when retina is exposed to an intense light environment for a long time.It is necessary to study how to protect the retina against light-induced injury in ophthalmology.Objective The aim of this study was to evaluate the effect of anthocyanidin extracts in preventing retinal photic damage.Methods Eighteen clean male Sprague-Dawley (SD) rats were randomly assigned to normal saline group,anthocyanidin group and mixed (hydrogen-rich saline (HRS) + anthocyanidin,11 in volume) group and 6 rats for each.The electroretinogram (ERG) with international standardized 5 items was recorded from all the rats before experiment.Normal saline,anthocyanidin extracts or mixed solution of 5 ml/kg were intraperitoneally injected in the three groups,respectively,for consecutive 5 days.Then the diffused light with the luminance intensity of (5000±300)lx was used to irradiate the right eyes of the rats for consecutive 3 hours during 1900 through 700 in a device made by our laboratory,and the left eyes were covered at the same time.The ERG was repeatedly recorded 5 days after light irradiation.The rats were sacrificed at the end of the experiment and retinal sections were prepared for the histopathological examination.The functional and structural changes of retinas were compared among the different groups.The use of the rats followed the Statement of ARVO.Results The differences of rat body weight were not statistically significant among the three groups (before experimentF =0.472,P =0.841 ; after experimentF =0.658,P=0.762).No any significant difference was found in scotopic 0.01 ERG b wave,scotopic 3.0 ERG a and b waves,scotopic 3.0 oscillatory potentials,photopic 3.0 ERG b wave and 3.0 flicker P1wave between the left eyes and the right eyes in the three groups before experiment (P＞0.05).The amplitudes of various waves of ERG were significantly declined in the right eyes compared with the left eyes (P＜0.05).The mean differential values of scotopic 0.01 ERG b wave,scotopic 3.0 ERG a and b waves,scotopic 3.0 oscillatory potentials were significantly different(F =4.594,P=0.029; F=3.834,P=0.037; F=12.823,P=0.000; F=3.976,P=0.032),but those in photopic 3.0 ERG b wave were not statistically significant (F =1.488,P =0.259).Compared with the normal saline group,the differential values of scotopic 0.01 ERG b wave,scotopic 3.0 ERG a and b waves,scotopic 3.0 oscillatory potentials were all reduced in the anthocyanidin group and mixed group (P ＜ 0.05).The cells of outer nuclear layer were decreased in the right eyes in the three groups compared with the left eyes,especially around the optic nerve head and the upside of the retina,with significant differences between them (P＜0.05),and those in the anthocyanidin group and mixed group were significantly less than normal saline group (P＜0.05).Conclusions Anthocyanidin has a protective effect on light-induced retinal damage of SD rats.The protective effect of anthocyanidin extracts is similar to the integrated effect of the mixed group.