Anti-inflammatory activity of β-patchoulene isolated from patchouli oil in mice

β-Patchoulene (β-PAE) is a tricyclic sesquiterpene isolated from the oil of Pogostemon cablin (patchouli oil), which has been widely used in traditional Chinese medicine for the treatment of inflammatory diseases. However, as one of the major principle of patchouli oil, the biological activity of β-PAE has not been explored so far. In the present study, the anti-inflammatory activity in vivo, and the underlying mechanism, of β-PAE was investigated on experimental mice models of acute inflammation, i.e. xylene-induced ear edema, acetic acid-induced vascular permeability and carrageenan-induced paw edema. The results showed that β-PAE evoked a significant dose-dependent inhibition of ear edema induced by xylene, paw edema induced by carrageenan and suppressed the increase of vascular permeability elicited by acetic acid. Histopathological analysis indicated that β-PAE could markedly decrease the cellular infiltration in paw tissue. β-PAE was also shown to significantly decrease the malondialdehyde (MDA) level and myeloperoxidase (MPO) activity in edema paw. In addition, carrageenan-induced production of some pro-inflammatory cytokines: tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), prostaglandin E2 (PGE2) and nitric oxide (NO), were suppressed in a dose-dependent manner in mice subjected to β-PAE pretreatment, and it also significantly down-regulated the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Further analysis revealed that β-PAE also inhibited the translocation of nuclear factor-κB (NF-κB) from the cytoplasm to the nucleus and stabilize the conversion of nuclear factor-κBα (IκBα) level. These results provided additional chemical and pharmacological basis for the traditional application of P. cablin in inflammatory disorders.