Six herbs essential oils suppressing inflammatory responses via inhibiting COX-2/TNF-α/IL-6/NF-κB activation

Frankincense, Myrrh, Radix aucklandiae, Matricaria chamomilla, Jasminum sambac and Syzygium aromaticum have been widely used as Chinese herbs. The composition and anti-inflammatory activity of essential oils from Frankincense, Myrrh, R. aucklandiae, M. chamomilla, J. sambac and S. aromaticum are analyzed in this study. The dominant compositions of Frankincense essential oils are octyl acetate (39.62%), octane-1-ol (10.23%) and eucalyptol (7.42%). The major components of Myrrh essential oils are α-elemene (13.17%), β-elemene (7.92%), germacrene D (6.85%) and α-copaene (6.42%). The main compositions of R. aucklandiae essential oils are 1,4,8-cyclododecatriene (10.88%), γ-costol (10.4%), γ-gurjunenepoxide-(2) (8.18%) and caryophyllene oxide (5.67%). The major compositions of M. chamomilla oils are (E)-tonghaosu (30.83%), α-bisabolone oxide A (18.89%), α-bisabolone oxide B (10.73%) and chamazulene (6.63%). The major compounds of J. sambac and S. aromaticum essential oils are eugenol with a percentage of 52.47% and 96.71%, respectively. In TPA-induced ear edema assay, most of essential oils reveal decent anti-inflammatory activity, especially that Myrrh, R. aucklandiae and M. chamomilla essential oils are even better than commercial anti-inflammatory medicine (ibuprofen), via markedly down-regulating the expression of inflammatory cytokines, like cyclooxygenase 2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and nuclear factor-κB (NF-κB) in vivo. Therefore, it is reasonably speculated that these natural essential oils will be potential anti-inflammatory drug for inflammation with little side effects.