Figure 5. CMS decreased the level of ROS in HG-treated hRMECs. (A) Representative images of ROS shown by CM-H2DCFDA staining (green) in hRMECs treated with sh-NC, sh-SIRT1, sh-SIRT1 + DMSO and sh-SIRT1 + CMS, respectively (× 400) (scale bar = 25 μm). (B) Relative fluorescence in the hRMECs. (C) Quantitative analysis of ROS content in hRMECs. * p < 0.05, ** p < 0.01, *** p < 0.001, compared to sh-NC-treated hRMECs and # p < 0.05, ## p < 0.01, ### p < 0.001, compared to the hRMECs treated with sh-SIRT1 + DMSO. The results were measurement data and expressed as mean ± standard deviation. Comparisons between multiple groups were analyzed by one-way ANOVA with Tukey’s post hoc test. The cell experiments were repeated three times independently. CMS, coumestrol, ROS, reactive oxygen species; hRMECs, human retinal microvascular endothelial cells; SIRT1, sirtuin 1; DMSO, dimethyl sulfoxide; ANOVA, analysis of variance.