Figure 2. Intracellular reactive oxygen species (ROS) levels in ARPE-19 cells when pretreated with myricitrin, myricetin, leaf extract of Syzygium malaccense, and F2 (myricetin derivatives) for 2 h before exposure to GO-H₂O₂ induced stress. The concentration of glucose oxidase (GO) used is 12 mUnit/ml. Intracellular ROS that was generated during the incubation period was monitored using the 2′,7′-dichlorofluorescin diacetate (DCFH-DA) fluorescent probe. Control (100%) is the untreated cells grown in basal medium. The fold change was normalized to 10,000 cells for all GO-treated cells with and without pretreatment of samples by considering the number of viable cells after the treatment. Data are expressed in mean ± standard deviation (SD), n=3. The paired t test between the GO-treated cells and control showed statistical significance at ^###p<0.001. The one-way ANOVA Tukey’s post hoc test showed statistical significance at *p<0.05, ** p<0.01, and *** p<0.001 when the test samples were compared to the GO-treated cells. S. mal = Syzygium malaccense.