Anti-inflammatory effects of compounds alpha-humulene and (-)-trans-caryophyllene isolated from the essential oil of Cordia verbenacea

This study evaluated the anti-inflammatory properties of two sesquiterpenes isolated from Cordia verbenacea's essential oil, (X-humulene and (-)-trans-caryophyllene. Our results revealed that oral treatment with both compounds displayed marked inhibitory effects in different inflammatory experimental models in mice and rats. alpha-humulene and (-)-trans-caryophyllene were effective in reducing platelet activating factor-, bradykinin- and ovoalbumin-induced mouse paw oedema, while only alpha-humulene was able to diminish the oedema formation caused by histamine injection. Also, both compounds bad important inhibitory effects on the mouse and rat carrageenan-induced paw oedema. Systemic treatment with alpha-humulene largely prevented both tumor necrosis factor-alpha (TNF alpha) and interieukin-1 beta (IL-1 beta) generation in carrageenan-injected rats, whereas (-)-trans-caryophyllene diminished only TNF alpha release. Furthermore, both compounds reduced the production of prostaglandin E, (PGE(2)), as well as inducible nitric oxide symbase (NOS) and cyclooxygenase (COX-2) expression, induced by the intraplantar injection of carrageenan in rats. The anti-inflammatory effects of a.-humulene and (-)-trans-caryopfiyllene were comparable to those observed in dexametbasone-treated animals, used as positive control drug. All these findings indicate that alpha-humulene and (-)-trans-caryophyllene, derived from the essential oil of C. verbenacea, might represent important tools for the management and/or treatment of inflammatory diseases. (c) 2007 Elsevier B.V. All rights reserved.