Anti‐inflammatory effect of buddlejasaponin IV through the inhibition of iNOS and COX‐2 expression in RAW 264.7 macrophages via the NF‐ κ B inactivation

1 Buddlejasaponin IV isolated from Pleurospermum kamtschatidum is an anti‐inflammatory compound that inhibits NO, PGE 2 and TNF‐ α production. Here, we studied the mode of action of this compound. 2 Buddlejasaponin IV (2.5–10  μ M ) reduced lipopolysaccaride (LPS (1  μ g ml −1 ))‐induced levels of iNOS and COX‐2 at the protein levels, and iNOS, COX‐2, TNF‐ α , interleukin (IL)‐1 β and IL‐6 mRNA expression in RAW 264.7 macrophages in a concentration‐dependent manner, as determined by Western blotting and RT–PCR, respectively. 3 Buddlejasaponin IV inhibited the LPS‐induced activation of nuclear factor‐ κ B (NF‐ κ B), a transcription factor necessary for proinflammatory mediators, iNOS, COX‐2, TNF‐ α , IL‐1 β and IL‐6 expression. This effect was accompanied by a parallel reduction in I κ B‐ α degradation and phosphorylation, and by the nuclear translocation of the NF‐ κ B p65 subunit. 4 The effects of buddlejasaponin IV on acute phase inflammation were studied on serotonin‐ and carrageenan–induced paw edema. The antiedematous effect of buddlejasaponin IV was compared with 10 mg kg −1 of indomethacin p.o. Maximum inhibitions of 26 and 41% were noted at a dose of 20 mg kg −1 for serotonin‐ and carrageenan‐induced paw edema, respectively. 5 The analgesic effect of buddlejasaponin IV was evaluated using acetic acid‐induced writhing and hot‐plate tests. Buddlejasaponin IV (10 and 20 mg kg −1 , p.o.) was found to have a marked analgesic effect in both models. 6 These results suggest that the inhibitions of the expressions of iNOS, COX‐2, TNF‐ α , IL‐1 β and IL‐6 by blocking NF‐ κ B activation, are responsible for the anti‐inflammatory effects of buddlejasaponin IV isolated from P. kamtschatidum .British Journal of Pharmacology (2006) 148 , 216–225. doi: 10.1038/sj.bjp.0706718