Figure 9.

Induction of ROS production by compounds 3a, 3b, and 3d. The data show a significant dose-dependent increase in CellROX^® Deep Red fluorescence intensity for compounds 3a and 3b. Interestingly, compound 3a showed only a small (1.1-fold) increase in ROS production at 12.5 µM (below its IC₅₀), but the ROS production increased to 7.1 times relative to the control at 25 µM. This indicates a significant dose-dependent increase in ROS production in the presence of this substance. Other substituted isatins 3b and 3d led to increased ROS production relative to the control. **—p < 0.01 and ****—p < 0.0001 versus control. The statistical analysis was performed using a one-way ANOVA and the Dunnett test.