title: Pharmacokinetics of valerenic acid after administration of valerian in healthy subjects.
abstract: OBJECTIVE
  To describe the pharmacokinetics of valerenic acid in a group of healthy adults after a single oral dose of valerian using a newly developed sensitive assay for serum concentrations of valerenic acid, a commonly used marker for qualitative and quantitative analysis of valerian root and valerian products.
  
  
  METHODS
  Six healthy adults (22-61 years, five men, one female) received a single 600 mg dose of valerian at 08:00. Blood samples were collected for 8 h after administration. Valerenic acid was extracted from serum and measured using a LC/MS/MS method developed in our laboratory.
  
  
  RESULTS
  The maximum serum concentration of valerenic acid for five of the six subjects occurred between 1 and 2 h ranging from 0.9 to 2.3 ng/mL. Valerenic acid serum concentrations were measurable for at least 5 h after the valerian dose. One subject showed a peak plasma value at 1 h and a second peak at 5 h. The elimination half-life (T(1/2)) for valerenic acid was 1.1 +/- 0.6 h. The area under the concentration time curve (AUC) as a measure of valerenic acid exposure was variable (4.80 +/- 2.96 microg/mL. h) and not correlated with subject's age or weight.
  
  
  CONCLUSIONS
  Assuming that valerenic acid serum concentrations correlate with the pharmacological activity of valerian, the timing of the valerenic acid peak concentration is consistent with the standard dosage recommendation to take valerian 30 min to 2 h before bedtime. Ongoing studies are evaluating the relationship between valerenic acid serum concentrations and objective measures of sleep in patients.
authors.affiliation: Department of Pharmacy, University of Washington, Seattle, 98195, USA. gaila@u.washington.edu
authors.forename: Gail D
authors.initials: GD
authors.lastname: Anderson
authors.forename: Gary W
authors.initials: GW
authors.lastname: Elmer
authors.forename: Eric D
authors.initials: ED
authors.lastname: Kantor
authors.forename: Ian E
authors.initials: IE
authors.lastname: Templeton
authors.forename: Michael V
authors.initials: MV
authors.lastname: Vitiello
mesh_terms: D000284:Administration, Oral; D000328:Adult; D019540:Area Under Curve; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D007192:Indenes / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D008297:Male; D008875:Middle Aged; D008517:Phytotherapy; D012717:Sesquiterpenes / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D014632:Valerian
chemical_list: D006993:Hypnotics and Sedatives; D007192:Indenes; D012717:Sesquiterpenes; C037133:valerenic acid