title: Lavender oil suppresses indoleamine 2,3-dioxygenase activity in human PBMC.
abstract: BACKGROUND
  Lavender remedies have been used in traditional medicine because of antimicrobial, anti-inflammatory and mood alleviating effects, but underlying molecular mechanisms are not yet fully elucidated. Recently, studies investigating the effects of lavender oil in the context of psychiatric disorders have indicated potent pharmacological properties. Metabolism of tryptophan by indoleamine 2,3-dioxygenase (IDO) was found to provide a biochemical link between immunology and neuroendocrinology and to be a frequent target of natural products.
  
  
  METHODS
  In this in vitro study, interferences of lavender oil and constituents (-)-linalool, (+)-α-pinene and (+)-limonene with tryptophan catabolism by IDO and formation of neopterin via guanosine triphosphate (GTP)-cyclohydrolase-I and of interferon-γ have been investigated using unstimulated and phytohemagglutinin (PHA)-stimulated human peripheral blood mononuclear cells (PBMC).
  
  
  RESULTS
  Treatment with lavender oil dose-dependently suppressed PHA-induced tryptophan breakdown and kynurenine formation. Similar effects were observed for the three constituents. In parallel, formation of neopterin and interferon-γ was diminished upon lavender oil treatment. In unstimulated PBMC, effect of lavender oil treatment was similar, but less pronounced.
  
  
  CONCLUSIONS
  Data from this in vitro study suggest that lavender oil treatment might contribute to the modulation of the immune and neuroendocrine system by interfering with activation-induced tryptophan breakdown and IDO activity.
authors.forename: Johanna M
authors.initials: JM
authors.lastname: Gostner
authors.forename: Markus
authors.initials: M
authors.lastname: Ganzera
authors.forename: Kathrin
authors.initials: K
authors.lastname: Becker
authors.forename: Simon
authors.initials: S
authors.lastname: Geisler
authors.forename: Sebastian
authors.initials: S
authors.lastname: Schroecksnadel
authors.forename: Florian
authors.initials: F
authors.lastname: Überall
authors.forename: Harald
authors.initials: H
authors.lastname: Schennach
authors.affiliation: Division of Biological Chemistry, Biocenter, Medical University of Innsbruck, Innsbruck, Austria. dietmar.fuchs@i-med.ac.at.
authors.forename: Dietmar
authors.initials: D
authors.lastname: Fuchs
mesh_terms: D000080462:Acyclic Monoterpenes; D000081008:Bicyclic Monoterpenes; D002478:Cells, Cultured; D053138:Cyclohexenes / Q000494:pharmacology; D006801:Humans; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000037:antagonists & inhibitors*; D007371:Interferon-gamma / Q000378:metabolism; D007737:Kynurenine / Q000378:metabolism; D027523:Lavandula / Q000737:chemistry*; D007963:Leukocytes, Mononuclear / Q000187:drug effects* / Q000201:enzymology; D000077222:Limonene; D039821:Monoterpenes / Q000494:pharmacology; D019798:Neopterin / Q000378:metabolism; D009822:Oils, Volatile / Q000737:chemistry / Q000494:pharmacology*; D010835:Phytohemagglutinins / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology*; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology*; D013729:Terpenes / Q000494:pharmacology*; D014364:Tryptophan / Q000378:metabolism*
chemical_list: D000080462:Acyclic Monoterpenes; D000081008:Bicyclic Monoterpenes; D053138:Cyclohexenes; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D039821:Monoterpenes; D009822:Oils, Volatile; D010835:Phytohemagglutinins; D010936:Plant Extracts; D010938:Plant Oils; D013729:Terpenes; D007737:Kynurenine; D019798:Neopterin; D007371:Interferon-gamma; D014364:Tryptophan; D000077222:Limonene; C018584:linalool; C005451:alpha-pinene; C045718:lavender oil