Effect of p38 MAP kinase, ERK and JNK inhibitors on TNF-α release from human monocytes. Monocytes were treated for 18 h with increasing concentrations of VT1 or VT2 (a), or were pretreated with SB203580 (10 μM), SP600125 (10 μM) or PD98059 (50 μM) for 45 min then stimulated with VT1 or VT2 (3 ng ml−1) for 18 h (b–d). After this period, cell supernatants were collected and TNF-α release was measured by ELISA as outlined in the methods. Each graph is representative of at least three independent experiments±s.d., n=3. *P<0.05 compared to control.