Figure 4.

Hispidin induces c-Jun N-terminal kinase (JNK) activation in ARPE-19 cells exposed to H₂O₂-induced oxidative stress. (A) ARPE-19 cells were treated with or without hispidin (20 μM) for 24 h and then treated with 300 μM H₂O₂ for 10–360 min. Proteins were collected and subjected to analyze the expression levels of p-ERK, p-JNK, and p-p38, which were then evaluated by Western blot. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was used as an internal control. (B) ARPE-19 cells were treated with hispidin for 24 h in the presence or absence of the mitogen-activated protein kinase (MAPK) pathway inhibitors, followed by a 300 μM H₂O₂ treatment for 24 h. Cell viability was analyzed by MTT assay. * p < 0.05, ** p < 0.01, *** p < 0.001 versus hispidin+H₂O₂ group.