Effect of CWE on PMA-stimulated ERK1/2 activation. A-B: THP-1 cells were incubated with or without U0126 (20 μM) or CWE in the presence of PMA for 72 h. C-D: THP-1 cells were preincubated with or without U0126 (20 μM) or CWE for 1 h and then stimulated with PMA for 30 min. SRA protein and phospho-ERK1/2 were analyzed by Western blotting. Actin or ERK1/2 was used as endogenous control. One representative Western blot of four experiments is shown.