Anti-cataract effects of Dajizhi(Euphorbium) eye drops on selenite-induced cataracts in rats

OBJECTIVE:To evaluate the effects of Dajizhi(Euphorbium)on selenite-induced cataracts.METHODS:Wistar rat pups were divided into 9 groups.Rats in group 1 were subcutaneously injected with saline,and rats in the other groups were injected with sodium-selenite.Every right eye was treated with 5μL eye drops 3 times per day,and the left eye received no treatment.The eyes of rats in group 3 were treated with pirenoxine;rats in groups 4,5,6,7,8 and 9 were respectively treated with Dajizhi(Euphorbium)(25 mg/m L),Dajizhi(Euphorbium)(5 mg/m L),Dajizhi(Euphorbium)methanol extract(25 mg/m L),Dajizhi(Euphorbium)methanol extract(5 mg/m L),euphol(25 mg/m L),euphol(5 mg/m L).Cataracts were observed by a slit lamp before and after treatment.Electroretinograms were acquired at set intervals.The morphological changes of the rat eyes were observed in vitro,and the levels of glutathione peroxidase(GSH-Px)and superoxide dismutase(SOD)in the lenses and aqueous humour were estimated at set intervals.RESULTS:Slit lamp examination showed decreased degrees of cataracts after administration of the different treatments.Morphological comparison showed that Dajizhi(Euphorbium)can reduce the turbidity of the lenses,meaning that Dajizhi(Euphorbium)has the anti-cataract effects.Low-concentration of Dajizhi(Euphorbium),its methanol extract and euphol treatment prevented the b-wave amplitudes of the electroretinograms from falling.Euphorbium treatment significantly restored GSH-Px and SOD levels in the lenses and aqueous humour,especially after 10 and 25 d of administration.Euphorbium may help lenses fight oxidative stress caused by selenite.CONCLUSION:The administration of Dajizhi(Euphorbium)can inhibit selenite-induced cataracts.

Retinal damage after exposure to white light emitting diode lights at different intensities in Sprague-Dawley rats

Background:The usage of the light emitting diode(LED)has been increasingly applied in the illumination setting and electronic equipment.However,the effect of LED lights on the retina remains unclear.In this study,we observed and analyzed the impact of white LED lights at different intensities on the function and morphology of rat retinas.Methods:Thirty-six Sprague-Dawley rats weighing 150-180 g were randomly divided into six groups(n=6 in each group)including a normal control(NC)group,4 white LED groups at different light intensities(4,000,6,000,7,000,and 10,000 lux),and an ultraviolet B(UVB)lighting group(302 nm,1,000μw/cm2).After 24 hours of continuous illumination,full-field flash electroretinogram(FERG)and pathological examination were performed in each group.Results:As revealed by FERG,the impairment of retinal function gradually worsened with the increase of LED light intensity.In contrast,the UVB group had the most severe retinal function impairment.Particularly,the functional damage of rod cells and inner nuclear layer cells was the main FERG finding in each group.In the NC group,the retina had typical morphologies featured by well-defined structures,clearly visible border between the inner and outer segments,and neatly arranged inner and outer nuclear layer cells.After 24 hours of illumination,the inner and outer parts of the retina in the 4,000 lux group were still neatly arranged,along with a clear border;however,the inner and outer nuclear layers were randomly arranged,and some irregular nuclei and cells were lost.The damage of the internal and external retinal segments and the internal and external nuclear layers became more evident in the 6,000 lux group,7,000 lux group,and 10,000 lux group.The UVB group had a more obviously disordered arrangement of inner and outer nuclear layers and loss of cells.Conclusions:Continuous exposure to white LED light can cause structural and functional damage to rat retinas,and such damage is related to the intensity of illumination.Therefore,the risk of retinal damage should be considered during LED illumination,and proper LED illumination intensity may help to maintain eye health.

Sirolimus eye drops inhibit acute alkali-burn-induced corneal neovascularization by regulating VEGFR2 and caspase-3 expressions

Background:To investigate the effect of sirolimus(SRL)eye drops on acute alkali-burn-induced corneal neovascularization(CNV)and explore its possible mechanism.Methods:A total of 57 male Sprague-Dawley rats weighing 160-180 g were randomly divided into four groups including a normal control group(NC group,n=12),an untreated alkali-burned model control group(MC group,n=15),a blank eye drop treatment group(BT group,n=15),and an SRL eye drop treatment group(ST group,n=15).Corneal inflammation and CNV were observed and scored under a slit-lamp microscope 3,7,and 14 days after alkali exposure.Three rats were randomly sacrificed in each group before modeling and 3,7,14 days after modeling,and the corneas of right eyes were harvested for Western blotting to compare the expression levels of VEGFR2 and caspase-3.Results:Corneal inflammation scoring showed that the corneal edema and conjunctival congestion were severe in the MC,BT,and ST groups 1 day after alkali exposure but were alleviated at day 3.The corneal transparency was significantly higher in the ST group than in the MC and BT groups at days 7(F=9.77,P<0.05)and 14(F=5.81,P<0.05).At day 1,the corneal limbal vascular network was markedly filled.SNV was obvious at days 3,7,and 14.The new blood vessels were shorter and sparser in the ST group than in the MC and BT groups,and the CNV scores showed significant differences among these groups(day 3:F=8.60,P<0.05;day 7:F=11.40,P<0.05;and day 14:F=41.59,P<0.01).Western blotting showed that the expressions of VEGFR2 and caspase-3 were low before modeling and showed no significant difference among the different groups(F=0.52,P>0.05;F=0.98,P>0.05).The corneal expression of VEGFR2 became significantly higher in the MC and BT groups than in the ST group 3,7,and 14 days after alkali exposure,and there were significant differences in relative gray-scale values among these groups(day 3:F=32.16,P<0.01;day 7:F=85.96,P<0.01;day 14:F=57.68,P<0.01).The increase in the corneal expression of caspase-3 was significantly larger in the ST group than in the MC and BT groups at days 3,7,and 14,and there were significant differences in relative gray-scale values among groups(day 3:F=32.16,P<0.01;day 7:F=53.02,P<0.01;day 14:F=38.67,P<0.01).Conclusions:SRL eye drops can alleviate acute alkali-burn-induced corneal inflammation and inhibit alkali-burn-induced CNV in rat models.It can reduce VEGFR2 expression and increase caspase-3 expression in the corneal tissue,which may contribute to the inhibition of alkali-burn-induced CNV.