Composition and Biological Activity of the Essential Oils from Wild Horsemint, Yarrow, and Yampah from Subalpine Meadows in Southwestern Montana: Immunomodulatory Activity of Dillapiole

Agastache urticifolia (Benth.) Kuntze (horsemint), Achillea millefolium L. (yarrow), and Perideridia gairdneri (Hook. & Arn.) Mathias (yampah) are native, culturally important plants that grow in the subalpine meadows of Montana. Analysis composition essential oils extracted from these showed main components obtained flowers leaves A. (designated as AUF/AUL) were menthone (2.7/25.7%), isomenthone (2.6/29.1%), pulegone (78.9/28.8%), limonene (4.2/6.2%), whereas inflorescence AMI) high α-thujone (17.1%) β-thujone (14.9%), 1,8-cineole (17.0%), camphor (13.0%), sabinene (7.0%), guaia-3,9-dien-11-ol (3.2%), terpinen-4-ol (2.5%). Essential P. PGI) contained amounts dillapiole (30.3%), p-cymen-8-ol (14.1%), terpinolene (12.0%), 4-hydroxy-4-methyl-cyclohex-2-enone (6.2%), γ-terpinene (2.4%). Evaluation their immunomodulatory activity demonstrated all could activate human neutrophils with varying efficacy. individual activated neutrophil intracellular Ca2+ flux ([Ca2+]i) (EC50 = 19.3 ± 1.4 μM), while α-thujone, β-thujone, menthone, isomenthone, inactive. Since neutrophils, we also evaluated if it was able to down-regulate responses subsequent agonist activation found pretreatment inhibited by chemoattractant fMLF (IC50 34.3 2.1 μM). Pretreatment oil or chemotaxis induced fMLF, suggesting treatments inflammatory chemoattractants. Thus, may be a novel modulator function.