Figure 3.

Activation of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling is corelated with the protective effect of hispidin against H₂O₂-induced cell death on ARPE-19 cells. (A) Cells were treated with various concentrations (2.5–20 μM) of hispidin for 24 h, and the expression levels of Nrf2, heme oxygenase-1 (HO-1), NAD(P)H:Quinine oxidoreductase-1 (NQO-1), glutamate-cysteine ligase catalytic subunit (GCLC), glutamate-cysteine ligase modifier subunit (GCLM), catalase, superoxide dismutase 1 (SOD1), and superoxide dismutase 2 (SOD2) were analyzed by Western blot or real-time PCR (B). (C) Cells were transfected with 40 μM Nrf2 siRNA or scramble siRNA (#) for 48 h, and then pre-treated with hispidin for 24 h, followed by 24 h H₂O₂ treatment. Protein levels of Nrf2, HO-1, and NQO-1 were analyzed by Western blot, and cell viability was assessed by MTT assay (D). * p < 0.05 versus hispidin+H₂O₂ group.