title: N-Acyl ethanolamide and eicosanoid involvement in irritant dermatitis.
abstract: BACKGROUND
  Sodium lauryl sulfate (SLS) and ultraviolet radiation (UVR) are two commonly encountered cutaneous inflammatory stimuli. Differing histopathological and clinical features implicate involvement of alternative inflammatory pathways; bioactive lipid mediators (eicosanoids, endocannabinoids and sphingolipids) are likely candidates for regulation of the divergent inflammatory responses.
  
  
  OBJECTIVE
  To assess comprehensively bioactive lipid involvement in SLS- and UVR-induced inflammatory responses, to provide a better understanding of bioactive lipid mediator pathways in irritant inflammation.
  
  
  METHODS
  Buttock skin from 10 healthy volunteers was treated with two minimal erythema doses of UVR (275-380 nm, peak 305 nm) or an SLS dose optimized for each individual, to produce a comparable, moderate erythema. Punch biopsies were taken 24 h postchallenge and from untreated skin, and separated into dermis and epidermis. Lipids [including 15 prostanoids, 15 hydroxy fatty acids (HFAs), nine endocannabinoids and related N-acyl ethanolamides (NAE), and 21 sphingolipids] were extracted and quantified using liquid chromatography-tandem mass spectrometry.
  
  
  RESULTS
  Increased epidermal NAE and HFA expression was observed in response to SLS but not UVR-induced low-level inflammation. Significant changes following SLS treatment included augmented levels of NAE, possessing proinflammatory and some reported anti-inflammatory properties, with 3·7-fold (P = 0·02) and threefold (P = 0·01) increased expression of palmitoyl and stearoyl ethanolamides, respectively, in addition to 1·9-fold (P = 0·02) increased expression of 12-hydroxyeicosatetraenoic acid.
  
  
  CONCLUSIONS
  The differential bioactive lipid upregulation implicates their involvement in skin irritant responses, potentially reflecting roles in inflammatory cell recruitment and subsequent resolution of inflammation, giving scope for new treatment approaches to irritant dermatitis.
authors.affiliation: Manchester Pharmacy School, Institute of Inflammation and Repair, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, U.K.
authors.forename: A C
authors.initials: AC
authors.lastname: Kendall
authors.affiliation: Dermatology Centre, Institute of Inflammation and Repair, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, U.K.|Salford Royal NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, U.K.
authors.forename: S M
authors.initials: SM
authors.lastname: Pilkington
authors.affiliation: Safety and Environmental Assurance Centre, Unilever, Sharnbrook, MK44 1LQ, U.K.
authors.forename: G
authors.initials: G
authors.lastname: Sassano
authors.affiliation: Dermatology Centre, Institute of Inflammation and Repair, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, U.K.|Salford Royal NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, U.K.
authors.forename: L E
authors.initials: LE
authors.lastname: Rhodes
authors.affiliation: Manchester Pharmacy School, Institute of Inflammation and Repair, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, U.K.
authors.forename: A
authors.initials: A
authors.lastname: Nicolaou
mesh_terms: D000328:Adult; D001095:Arachidonic Acids / Q000009:adverse effects*; D017453:Dermatitis, Irritant / Q000209:etiology*; D015777:Eicosanoids / Q000009:adverse effects* / Q000378:metabolism; D063388:Endocannabinoids / Q000009:adverse effects*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D010328:Patch Tests; D010787:Photosensitivity Disorders / Q000209:etiology; D053284:Polyunsaturated Alkamides / Q000009:adverse effects*; D012867:Skin / Q000187:drug effects / Q000528:radiation effects; D012967:Sodium Dodecyl Sulfate / Q000009:adverse effects; D013107:Sphingolipids / Q000378:metabolism; D014466:Ultraviolet Rays / Q000009:adverse effects; D055815:Young Adult
chemical_list: D001095:Arachidonic Acids; D015777:Eicosanoids; D063388:Endocannabinoids; D053284:Polyunsaturated Alkamides; D013107:Sphingolipids; D012967:Sodium Dodecyl Sulfate; C078814:anandamide