(A) HT-29 cells were treated with DPI, 104, 140, 392, or 428 for 24 h, and intracellular ROS production was detected by analytical cytometry using the redox-sensitive dye CM-H2-DCF-DA. (B) The effects of 24 h treatment with different concentrations of DPI on mitochondrial ROS levels in HT-29 cells were evaluated with the MitoSox™ reagent. (C) Upper panel: HT-29 cells received 2 h treatment with 2 μM DPI (blue line), alone or with 6 μM rotenone for 2 h (light green line), or with 2 mM KCN for 40 min (dark green line). The same experiments with 428 are displayed in the lower panel. Representative graphs over multiple experiments are shown.