title: Butterbur, a herbal remedy, attenuates adenosine monophosphate induced nasal responsiveness in seasonal allergic rhinitis.
abstract: BACKGROUND
  Butterbur (BB) or Petasites hybridus, a herbal remedy, exhibits in vitro inhibition of cysteinyl leukotriene biosynthesis. However, no placebo-controlled studies have been performed to evaluate the effectiveness of BB on objective outcomes such as nasal provocation testing in seasonal allergic rhinitis (SAR).
  
  
  METHODS
  Twenty patients with grass-pollen-sensitized SAR were randomized in a double-blind, cross-over manner to receive for 2 weeks either BB 50 mg twice daily or placebo (PL) twice daily during the grass pollen season. Nasal adenosine monophosphate (AMP) challenge (the primary outcome) was administered as a single 400 mg/mL dose after each randomized treatment.
  
  
  RESULTS
  Spontaneous recovery following AMP challenge (area under the response time profile curve as % x min+/-SEM) was significantly attenuated (P=0.028) with BB (584+/-289) compared to PL (1438+/-240); mean difference: 854 (95% CI 95-1614), and the maximum % peak nasal inspiratory flow reduction from baseline following AMP challenge was significantly blunted (P=0.036) with BB (30+/-4) compared to PL (43+/-5); mean difference: 13 (95% CI 1-25).
  
  
  CONCLUSIONS
  BB exhibited protection against AMP-induced nasal responsiveness during the grass pollen season in sensitized patients. This is turn may explain its potential clinical efficacy in patients with SAR.
authors.affiliation: Asthma & Allergy Research Group, Ninewells Hospital & Medical School, University of Dundee, Dundee, Scotland, UK.
authors.forename: D K C
authors.initials: DK
authors.lastname: Lee
authors.forename: I J
authors.initials: IJ
authors.lastname: Carstairs
authors.forename: K
authors.initials: K
authors.lastname: Haggart
authors.forename: C M
authors.initials: CM
authors.lastname: Jackson
authors.forename: G P
authors.initials: GP
authors.lastname: Currie
authors.forename: B J
authors.initials: BJ
authors.lastname: Lipworth
mesh_terms: D000249:Adenosine Monophosphate; D000293:Adolescent; D000328:Adult; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009299:Nasal Provocation Tests / Q000379:methods; D036901:Petasites; D008517:Phytotherapy / Q000379:methods*; D006255:Rhinitis, Allergic, Seasonal / Q000188:drug therapy*; D012717:Sesquiterpenes / Q000008:administration & dosage*; D013607:Tablets
chemical_list: D012717:Sesquiterpenes; D013607:Tablets; D000249:Adenosine Monophosphate; C418727:petasin