Apigeninsignificantly Protects Against Oxidative Injury In Retina Of Mice Associated With Activation Of Nrf2 Pathway

Objective:C57BL/6 mice were used to study the protective effect of apigenin on the retina of oxidized injury.To investigateNrf2 Signal pathway in the pathogenesisand the role of apigenin in the prevention of dry AMD,the differences of oxidative damage in the retina and the study of Nrf2 and related downstream target gene before and after drug intervention were compared.Methods:C57BL/6 mice were randomly divided into normal comparing group,model control group and administration group.In the model control group:high fat diet+hydroquinone modeling were used to cause oxidative damage to mouse retina,simulating dry AMD animal model;in the administration group:low dose apsein group(100mg/kg/d),middle dose apsein group(200mg/kg/d)and high dose apsein group(400mg/kg/d)were observed through electron microscopy.The thickness and width of sediment under the RPE,the thickness of Bruch film,the contents of SOD,GSH-Px,CAT and the contents of ROS and MDA in serum of mice were determined by colorimetry;the transcription and expression of Nrf2,HO-1,NQO-1 and GCL in the retina of normal animals and model animals were detected by real-time PCR and western blot.Results:Electron microscopy showed that the RPE of the retina was changed,and a large amount of lipid deposits were observed under the RPE layer.The Bruch film was thickened and showed typical pathological changes similar to that of AMD.Compared with model control group,the levels of total ROS in serum of low,middle and high dose groups were significantly lower than those in control group(P<0.01,P<0.01),and MDA content was also significantly decreased(low,medium and high dose group were P<0.01),the higher the concentration decreased the more obvious,dose-dependent relationship.It was suggested that apigenin could decrease the total ROS and MDA content in serum,and could improve the oxidative stress of the retina of model mice and reduce the damage of reactive oxygen species and various oxygen free radicals on mouse retina.Western Blot showed that the expression of Nrf2 protein in the cytoplasm was significantly decreased and the expression of Nrf2 protein in the nucleus was significantly increased after oxidative stress induced by high-fat diet and hydroquinone.It was confirmed that Nrf2 was in the nucleus when subjected to oxidative stress,the transfer was occurred to be the oxidative stress state.The expression of Nrf2,HO-1,NQO-1 and GCL mRNA in the model group was significantly higher than that in the normal comparing group(P<0.01),indicating that high-fat diet+hydroquinone modeling of the mouse body in the oxidative stress state,thus activating the Nrf2 channel,to stimulate the release of its own phase Ⅱ enzyme play antioxidant;After apigenin treatment,the expression levels of Nrf2,HO-1,NQO-1 and GCL mRNA in the administration group were decreased,compared with the model control group,suggesting that the expression of Nrf2,HO-1,NQO-1 and GCL mRNA in the administration group may be strongly oxidative stress after the model group was stimulated by oxidative stimulation to be stable.Conclusion:High fat diet+hydroquinone feeding,can successfully manufacture oxidative damage mouse retina model,by observing RPE changes,RPE sediment and Bruch film thickness,proved that the modeling method can successfully simulate the dry AMD animal model;Apigenin can improve the activity of antioxidant enzymes in serum of oxidized injured mice,decrease the content of ROS andMDA in serum,and thus play an anti-oxidative stress and dose-dependent;After treatment with apigenin,the expression levels of Nrf2,HO-1,NQO-1 and GCL mRNA in the administration group were decreased compared with the model control group,which may be the difference of oxidative/antioxidant balance between apigenin and model mice Of the state,the compensatory reduction of Nrf2 and other protein expression to increase the body’s antioxidant capacity,and then adjust the body balance in mice to reduce oxidative stress-induced damage.