title: Phytoncides (wood essential oils) induce human natural killer cell activity.
abstract: To explore the effect of forest bathing on the human immune system, we investigated the effect of phytoncides (wood essential oils) on natural killer (NK) activity and the expression of perforin, granzyme A and granulysin in human NK cells. We used NK-92MI cell, an interleukin-2 independent human NK cell line derived from the NK-92 cell, in the present study. NK-92MI cells express the CD56 surface marker, perforin, granzyme A, and granulysin by flow cytometry and are highly cytotoxic to K562 cells in chromium release assay. Phytoncides significantly increase cytolytic activity of NK-92MI cells in a dose-dependent manner and significantly increase the expression of perforin, granzyme A, and granulysin in the NK-92MI cells. Phytoncides also partially, but significantly, restore the decreased human NK activity and the decreased perforin, granzyme A, and granulysin expression in NK-92MI cells induced by dimethyl 2,2-dichlorovinyl phosphate (DDVP), an organophosphorus pesticide. Pretreatment with phytoncides partially prevents DDVP-induced inhibition of NK activity. Taken together, these data indicate that phytoncides significantly enhance human NK activity and this effect is at least partially mediated by induction of intracellular perforin, granzyme A, and granulysin.
authors.affiliation: Department of Hygiene and Public Health, Nippon Medical School, Tokyo, Japan. qing-li@nms.ac.jp
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
authors.forename: Ari
authors.initials: A
authors.lastname: Nakadai
authors.forename: Hiroki
authors.initials: H
authors.lastname: Matsushima
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Miyazaki
authors.forename: Alan M
authors.initials: AM
authors.lastname: Krensky
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Kawada
authors.forename: Kanehisa
authors.initials: K
authors.lastname: Morimoto
mesh_terms: D000943:Antigens, Differentiation / Q000276:immunology; D029779:Cupressaceae / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000276:immunology; D006801:Humans; D007155:Immunologic Factors / Q000737:chemistry / Q000494:pharmacology*; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000276:immunology*; D008213:Lymphocyte Activation / Q000187:drug effects* / Q000276:immunology; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000943:Antigens, Differentiation; D007155:Immunologic Factors; D010938:Plant Oils