The Protective Effect And Mechanism Of Resveratrol On Diabetic Retinopathy

Part ? The effect of Resveratrol on STZ-induced diabetic retinopathy ratsObjective:To investigate the potential protective effects of resveratrol(Res) on retina in diabetic rats induced by STZ, and then explore the possible mechanisms.Methods:Among 35 adult healthy male SD rats,10 were randomly divided into normal control group (Control),25 were used for the diabetic animal model with STZ.Successfully modeled 20 rats were randomly divided into diabetes mellitus group (DM group)and resveratrol treated group (DM+Res group) equally.The DM+Res group were had intragastric Res administration daily with 40 mg/Kg/day.The weight and blood glucose was measured at 0?4?8?12 weeks after the intragastric administration.After 12 weeks of Res administration, the eyes of three groups were dissected. The content of end product malondialdehyde (MDA) and activity of superoxide dismutase (SOD) in rat retinal were tested. Retinal histology was examined, and the thickness of the retina was measured. Ultrastructural changes in the retinal ganglion cells and capillary basement membrane were observed with electron microscopy. Apoptosis of retinal neural cells was determined with the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling assay.The expression of Bax and Bcl-2 in the retinal tissues was determined with immunohistochemical stainingResults:Compared with the DM group, the blood glucose level decreased (p<0.01) and the body weight increased (p<0.05) in Res-treated group. Compared with the DM group,the content of MDA in the Res group was significantly lower (P<0.01), and the activity of SOD of which were obviously increased (P<0.01). Meanwhile, the thickness of the retina significantly increased (p<0.01)in Res-treated group. Res treatment attenuated the diabetes-induced apoptotic of retinal neural cells and thickening of capillary BM. Consistent with these effects, Res treatment decreased Bax expression level and increased the Bcl-2 level, at the same time, increased the ratio of Bcl-2 to Bax.Conclusions:Res can reduce the blood glucose, ameliorate the body weight loss of diabetic rats, enhance antioxidative capacity of diabetic rat retina and reduce the oxidative damage of the retina. Meanwhile,Res can attenuate diabetes-induced apoptosis in retinal neurons by increasing the expression of Bcl-2?inhibiting Bax protein and increasing the ratio of Bcl-2-to-BaxPart ? Effect of resveratrol on ARPE-19 cells cultured in high glucose conditionObjective:To determine appropriate intervention time and appropriate intervention levels of Res on ARPE-19 cells in high glucose conditions and to investigate whether Res can protect ARPE-19 cells from high glucose damage induced by 30mmol/L glucose?Methods:ARPE-19 cells were cultured in DMEM including 30mmol/L glucose (setting normal glucose control and high mannitol control group) for 24h?48h and 72h,cell viability of all groups were evaluated by Cell counting Kit-8 (CCK-8) assay at the three time points to select the most appropriate intervention time.Then CCK-8 assay was used to quantify the cell viability of ARPE-19 cells cultured in high glucose with series concentration of resveratrol (O?mol/L?5?mol/L?1O?mol/L? 25?mol/L?50?mol/L)for 48h to select the most appropriate intervention levels of resveratrol.Finally,CCK-8 assay was used to quantify the cell viability of ARPE-19 cells cultured in DMEM including 30mmol/L glucose and 10?mol/L resveratrol (setting normal glucose control and high glucose control group for 48h,and cell momorphous was investigated by phase contrast inverted microscope.Results:When ARPE-19 cells cultured in different culture-medium for 48h,statistical difference appeared. And when the concentration of Res is 10?mol/L, the protective effect for ARPE-19 cells is the best.Compared with high-glucose group, the abnormal changes in the morphology of Res-treated group alleviated significantly.Conclusions:30mM high glucose can inhibit the viability of ARPE-19 cells cultured in vitro.The most appropriate intervention time is 48h and the most appropriate intervention levels of Res is 10?mol/L. In such conditions,Res can reduce the damage of ARPE-19 cells induced by high glucose in vitroPart ? The protective effect and mechanism of resveratrol on ARPE-19 cells cultured in high glucoseObjective:To investigate whether resveratrol has the protective effect on ARPE-19 cells cultured in high glucose and its possible mechanismMethods:ARPE-19 cells were divided into three groups:control group?high glucose group and high glucose plus resveratrol group. Apoptosis were analysed by flow cytometry, the expression of bax and bcl-2 was detected by immunofluorescence and western blot assays,ROS was detected by flow cytometry and immunofluorescence, mRNA expression levels of IL-1? and TNF-a were quantified by Real-time quantitative PCRResults:Compared with the high-glucose group, in Res-treated group the ratio of apoptosis reduced;the expression of bcl-2 increased and bax decreased, naturally the ratio of Bcl-2 to Bax increased;the production of ROS reduced and mRNA expression levels of IL-1? and TNF-? reduced.Conclusions:Res can attenuate high glucose-induced apoptosis of ARPE-19 cells by increasing the expression of Bcl-2?inhibiting Bax protein and increasing the ratio of Bcl-2-to-Bax;and reducing the production of ROS and decreasing the release of inflammatory cytokines.It might be the potential application of Res in the prevention and treatment of DR.