Figure 2. CMS decreased the level of ROS in the retinal tissues of DR rats. (A) Representative images of ROS shown by CM-H2DCFDA staining (green) in the retinal tissues of sham-operated and STZ-treated rats administrated with DMSO, 10 mg/kg CMS, 50 mg/kg CMS, and 100 mg/kg CMS (× 400) (scale bar = 25 μm). (B) Relative fluorescence in retinal tissues. (C) Quantitative analysis of ROS content in the retinal tissues. *p < 0.05, **p < 0.01, ***p < 0.001, compared to the sham-operated rats and #p < 0.05, ##p < 0.01, ###p < 0.001, compared to the rats injected with STZ and treated with DMSO. Data were shown as mean ± standard deviation. Comparisons between multiple groups were analyzed by one-way ANOVA with Tukey’s post hoc test. (n = 15). CMS, coumestrol, DR, diabetic retinopathy; STZ, streptozotocin; ROS, reactive oxygen species; DMSO, dimethyl sulfoxide; ANOVA, analysis of variance; n, number.