Figure 2.

Catalpol exerted anti-apoptotic protective effect on H₂O₂-induced RPE cells. (a) ARPE-19 cells were treated with H₂O₂ (400 μM) in the presence or absence of catalpol (10, 20 and 40 μM) for 6 h. TUNEL assay was preformed according to the manufacturer’s instructions. The apoptotic cells were identified and captured under fluorescence microscopy (scale bar = 10 μm). (b,c). The cells were incubated with either catalpol (10–40 μM, 24 h) or NAC (10 mM, 2 h) for 24 h before being treated with 400 μM H₂O₂ for 6 h. Cell apoptosis was measured with Annexin V–FITC assay. (d) Pretreatment with ML385, an Nrf2 inhibitor, blocked catalpol-mediated reduction in apoptosis in H₂O₂-treated ARPE-19 cells. 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).