Figure 5.

Effect of catalpol on ROS production and antioxidant enzyme activity in H₂O₂-treated RPE cells. (a) ARPE-19 cells were pretreated with or without catalpol (10, 20, and 40 μM) for 24 h and then treated with 400 μM H₂O₂ for 6 h. ROS production was measured and analyzed using the DCFH-DA assay. (b) The levels of cellular GSH, SOD, and MDA were determined. (c) Treatment with ML385, an Nrf2 inhibitor, blocked the antioxidant protective effects of catalpol on H₂O₂-treated ARPE-19 cells. The levels of cellular SOD2, CAT, GSH-Px, and ROS were determined. Data are presented as mean ± S.D. of three independent experiments (* p < 0.05 vs. control group, # p < 0.05 vs. H₂O₂ (400 μM)-treated group).