Suppression of tumor necrosis factor-alpha-induced neutrophil adherence responses by essential oils.
BACKGROUND
In aromatherapy, essential oils are used as anti-inflammatory remedies, but experimental studies on their action mechanisms are very limited.


OBJECTIVE
To assess their anti-inflammatory activities, effects of essential oils on neutrophil activation were examined in vitro.


METHODS
Neutrophil activation was measured by tumor necrosis factor-alpha (TNF-alpha)-induced adherence reaction of human peripheral neutrophils.


RESULTS
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.


CONCLUSIONS
Thus, some essential oils used as antiinflammatory remedies suppress neutrophil activation by TNF-alpha at a low concentration (0.0125-0.025 %) in vitro.
Abe
Shigeru
S
Teikyo University Institute of Medical Mycology, 350 Otsuka, Hachioji, Tokyo 192-0395, Japan.
Maruyama
Naho
N
Hayama
Kazumi
K
Ishibashi
Hiroko
H
Inoue
Shigeharu
S
Oshima
Haruyuki
H
Yamaguchi
Hideyo
H
D000080462:Acyclic Monoterpenes; D002448:Cell Adhesion / Q000187:drug effects; D002478:Cells, Cultured; D000081005:Cyclohexane Monoterpenes; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology; D039821:Monoterpenes / Q000494:pharmacology; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects*; D009822:Oils, Volatile / Q000737:chemistry / Q000494:pharmacology*; D013729:Terpenes / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D000080462:Acyclic Monoterpenes; D000081005:Cyclohexane Monoterpenes; D008070:Lipopolysaccharides; D039821:Monoterpenes; D009822:Oils, Volatile; D013729:Terpenes; D014409:Tumor Necrosis Factor-alpha; C006923:carvone; C007836:geraniol; D013755:Tetradecanoylphorbol Acetate; C007078:citronellol; C007076:citral