Suppression of inflammatory responses by celastrol, a quinone methide triterpenoid isolated from Celastrus regelii.

BACKGROUND

Celastrol, a quinone methide triterpenoid isolated from the Celastraceae family, exhibits various biological properties, including chemopreventive, antioxidant and neuroprotective effects. In this study, we showed that celastrol inhibits inflammatory reactions in macrophages and protects mice from skin inflammation.

METHODS

Anti-inflammatory effects of celastrol (0-1 microM) were examined in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. To investigate the effects of celastrol (0-50 microg per mice) in vivo, activation of myeloperoxidase (MPO) and histological assessment were examined in the 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced mouse ear oedema model.

RESULTS

Our in vitro experiments showed that celastrol suppressed not only LPS-stimulated generation of nitric oxide and prostaglandin E(2), but also expression of inducible nitric oxide synthase and cyclooxygenase-2 in RAW264.7 cells. Similarly, celastrol inhibited LPS-induced production of inflammatory cytokines, including tumour necrosis factor-alpha and interleukin-6. In an animal model, celastrol protected mice from TPA-induced ear oedema, possibly by inhibiting MPO activity and production of inflammatory cytokines.

CONCLUSIONS

Our data suggest that celastrol inhibits the production of inflammatory mediators and is a potential target for the treatment of various inflammatory diseases.