title: Gamma-linolenic acid levels correlate with clinical efficacy of evening primrose oil in patients with atopic dermatitis.
abstract: BACKGROUND
  Atopic dermatitis (AD) has been related to a deficiency of delta-6-desaturase, an enzyme responsible for the conversion of linoleic acid to gamma-linolenic acid (GLA). Evening primrose oil (EPO) contains high amounts of GLA. Therefore, this study investigated whether EPO supplementation results in an increase in plasma GLA and its metabolite dihomo-gamma-linolenic acid (DGLA) correlating with clinical improvement of AD, assessed by the SCORing Atopic Dermatitis (SCORAD) index.
  
  
  METHODS
  The open study included 21 patients with AD. EPO (4-6 g) was administered daily for 12 weeks. Before treatment, and 4 and 12 weeks after initiation of EPO supplementation, objective SCORAD was assessed and plasma concentrations of GLA and DGLA were determined by gas chromatography.
  
  
  RESULTS
  A significant increase in plasma GLA and DGLA levels and a decrease in the objective SCORAD were observed 4 and 12 weeks after initiation of EPO treatment. In the per-protocol population (n = 14), a significant inverse correlation between the changes in plasma GLA levels and SCORAD was found (P = 0.008).
  
  
  CONCLUSIONS
  The clinical disease activity under EPO treatment correlates with the individual increase in plasma GLA levels. Thus, the results of this pilot study indicate that an increase in plasma GLA might be used as predictive parameter for responsiveness of AD to EPO therapy.
authors.affiliation: Department of Dermatology, Inselspital, University Hospital of Bern, Bern, Switzerland.
authors.forename: Dagmar
authors.initials: D
authors.lastname: Simon
authors.forename: Peter A
authors.initials: PA
authors.lastname: Eng
authors.forename: Siegfried
authors.initials: S
authors.lastname: Borelli
authors.forename: Roland
authors.initials: R
authors.lastname: Kägi
authors.forename: Christian
authors.initials: C
authors.lastname: Zimmermann
authors.forename: Catherine
authors.initials: C
authors.lastname: Zahner
authors.forename: Jürgen
authors.initials: J
authors.lastname: Drewe
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Hess
authors.forename: Giovanni
authors.initials: G
authors.lastname: Ferrari
authors.forename: Stephan
authors.initials: S
authors.lastname: Lautenschlager
authors.forename: Brunello
authors.initials: B
authors.lastname: Wüthrich
authors.forename: Peter
authors.initials: P
authors.lastname: Schmid-Grendelmeier
mesh_terms: D015126:8,11,14-Eicosatrienoic Acid / Q000097:blood*; D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003876:Dermatitis, Atopic / Q000097:blood / Q000188:drug therapy*; D003879:Dermatologic Agents / Q000737:chemistry / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008041:Linoleic Acids / Q000737:chemistry / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D031665:Oenothera biennis; D010938:Plant Oils / Q000737:chemistry / Q000627:therapeutic use*; D011446:Prospective Studies; D016896:Treatment Outcome; D055815:Young Adult; D017965:gamma-Linolenic Acid / Q000032:analysis / Q000097:blood* / Q000737:chemistry / Q000627:therapeutic use
chemical_list: D003879:Dermatologic Agents; D008041:Linoleic Acids; D010938:Plant Oils; C028498:evening primrose oil; D017965:gamma-Linolenic Acid; D015126:8,11,14-Eicosatrienoic Acid