Figure 3.

Effect of catalpol on cell cycle arrest in H₂O₂-induced 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. The cell cycle progression was measured using PI assay. (b) The expression levels of related regulatory proteins in the cell cycle were determined with Western blot assay. β-actin was used as internal control. 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).