Suppression of tumor necrosis factor-alpha-induced neutrophil adherence responses by essential oils.

Kazumi Hayama,Shigeru Abe,Haruyuki Oshima,Shigeharu Inoue,Naho Maruyama,Hideyo Yamaguchi,Hiroko Ishibashi

doi:10.1080/09629350310001633342

Abstract

In aromatherapy, essential oils are used as anti-inflammatory remedies, but experimental studies on their action mechanisms are very limited. To assess their anti-inflammatory activities, effects of essential oils on neutrophil activation were examined in vitro. Neutrophil activation was measured by tumor necrosis factor-alpha (TNF-alpha)-induced adherence reaction of human peripheral neutrophils. All essential oils tested at 0.1% concentration suppressed TNF-alpha-induced neutrophil adherence,and, in particular, lemongrass, geranium and spearmint oils clearly lowered the reaction even at 0.0125%. Similar inhibitory activities for the neutrophil adherence were obtained by their major constituent terpenoids: citral, geraniol, citronellol and carvone. In contrast, very popular essential oils, tea tree oil and lavender oil, did not display the inhibitory activity at the concentration. Thus, some essential oils used as antiinflammatory remedies suppress neutrophil activation by TNF-alpha at a low concentration (0.0125-0.025 %) in vitro.

Highlights

Aromatherapy is a folk medicine originated from the traditional therapeutic use of essential oils, and in recent years it has attracted attention as one of the alternative medicines especially in the modern medical field
We have confirmed that addition of dimethyl sulfoxide (DMSO) (0.4%) to the medium has no significant effects on TNF-ainduced neutrophil adherence
Tea tree and lavender oils showed weak suppressing activity (IC50 0/0.033% and 0.027%, respectively), while eucalyptus oil showed no suppressing activity (IC50 /0.05%). These results indicate that the suppressing activities of the essential oils on tumor necrosis factor-alpha (TNF-a)-induced neutrophil adhesion differ

Summary

Introduction

Aromatherapy is a folk medicine originated from the traditional therapeutic use of essential oils, and in recent years it has attracted attention as one of the alternative medicines especially in the modern medical field. Several investigators found that tea tree oil[1] Á 3 and lavender oil[4] suppressed allergic symptoms through the suppression of histamine release[5,6] and cytokine production.[7] It is known that in inflammatory response, neutrophils accumulate around the lesional area infected by microbes, and play a major role in host defense responses. On the contrary, may induce excessive inflammatory responses and damage tissues around the area and make the symptoms worse by the secretion of superoxides, proteases and other antibacterial substances. These neutrophils are well recognized to play these major regulatory roles in inflammation, the effects of essential oils on neutrophil function have not been investigated.

Objectives

Methods

Results

Conclusion