JNK inhibitor suppressed the inhibitory effect of melittin and bee venom on the generation of NO induced by LPS or SNP. Raw 264.7 cells (A, C) or synoviocytes (B, D) were pretreated with 10 and 20 μM SP600125 1 hr prior to the treatment with melittin or bee venom with or without LPS (1 μg/ml) or SNP (200 μM) at 37°C for 24 hr. The amounts of NO in the medium of cultured Raw264.7 cells (A, C) or synoviocytes (B, D) were determined by the methods described in the methods. Results are expressed as means ± SE of three independent experiments performed in triplicate. * indicates significantly different from the LPS or SNP treated groups (p < 0.05). # and ##, indicates significantly different from LPS or SNP + melittin or BV treated group (p < 0.05).