Figure 6.

Roles of ERK1/2 and p38 MAPK in GHP-mediated cytoprotection against H₂O₂-induced oxidative damage in HepG2 cells. (A) Cells were pretreated with PD98059 or SB203580 (20 μM) for 2 h and then incubated with GHP (2.0 mg/mL), or not, for 12 h, followed by stimulation with H₂O₂ for 6 h. Cell viability was measured using MTT assay; (B) Cells were pretreated with either PD98059 or SB203580 each at a concentration of 20 μM for 2 h prior to incubation with GHP (2.0 mg/mL), or not, for additional 12 h, and then stimulated with H₂O₂ for 30 min. The intracellular ROS levels were measured by DCF-DA with fluorescent analysis. The results are presented as the means ± SD of four independent experiments. Means with different letters are significantly different from each other at p < 0.05.