Figure 6.

The propolis derivative, GS-002, induced ATF-3 expression that was mediated by MAPK pathways. Hep3B cells were treated with (a) 20 μg/mL GS-002 for the indicated time periods, or (b) with various concentrations of GS-002 for 1 h. Total cell lysates were used to detect protein expressions of p38, phosphor-p38 (p-p38), c-Jun N-terminal kinase (JNK), phospho-JNK (p-JNK), extracellular signal-regulated kinase (ERK), and phospho-ERK (p-ERK) by Western blotting. Ten micrograms of 15-deoxy-Δ12,14-prostaglandin J₂ (15d-PGJ₂) was used as a positive control. (c) Hep3B cells were pretreated with 5 and 10 μM of the p38 inhibitor, SB203580, the ERK inhibitor, PD98059, or the JNK inhibitor, SP600125, for 90 min, then treated with GS-002 (20 μg/mL) for another 12 h, and the ATF-3 protein level was detected by Western blotting.