title: Anxiolytic-like effects of acute and chronic treatment with Achillea millefolium L. extract.
abstract: BACKGROUND
  Achillea millefolium L. (Asteraceae), known as yarrow ("mil folhas"), has been used as folk medicine for gastrointestinal disorders, inflammation, anxiety, and insomnia.
  
  
  OBJECTIVE
  To evaluate the potential anxiolytic-like effect of hydroalcoholic extract of Achillea millefolium L. in animal models.
  
  
  METHODS
  The present study evaluated the effects of the hydroalcoholic extract from the aerial parts of Achillea millefolium L. in mice subjected to the elevated plus-maze, marble-burying, and open-field tests. Additionally, the GABA(A)/benzodiazepine (BDZ) mediation of the effects of Achillea millefolium was evaluated by pretreatment with the noncompetitive GABA(A) receptor antagonist picrotoxin and the BDZ antagonist flumazenil and by [(3)H]-flunitrazepam binding to the BDZ site on the GABA(A) receptor.
  
  
  RESULTS
  Achillea millefolium exerted anxiolytic-like effects in the elevated plus-maze and marble-burying test after acute and chronic (25 days) administration at doses that did not alter locomotor activity. This behavioral profile was similar to diazepam. The effects of Achillea millefolium in the elevated plus-maze were not altered by picrotoxin pretreatment but were partially blocked by flumazenil. Furthermore, Achillea millefolium did not induce any changes in [(3)H]-flunitrazepam binding.
  
  
  CONCLUSIONS
  The results indicate that the orally administered hydroalcoholic extract of Achillea millefolium L. exerted anxiolytic-like effects that likely were not mediated by GABA(A)/BDZ neurotransmission and did not present tolerance after short-term, repeated administration.
authors.affiliation: Instituto de Ciências Biológicas, Médicas e da Saúde - Farmacologia, Universidade Paranaense, Umuarama 87502-210, PR, Brazil. irineiapaulina@hotmail.com
authors.forename: Irinéia Paulina
authors.initials: IP
authors.lastname: Baretta
authors.forename: Regiane Américo
authors.initials: RA
authors.lastname: Felizardo
authors.forename: Vanessa Fávero
authors.initials: VF
authors.lastname: Bimbato
authors.forename: Maísa Gonçalves Jorge
authors.initials: MG
authors.lastname: dos Santos
authors.forename: Candida Aparecida Leite
authors.initials: CA
authors.lastname: Kassuya
authors.forename: Arquimedes
authors.initials: A
authors.lastname: Gasparotto Junior
authors.forename: Cássia Regina
authors.initials: CR
authors.lastname: da Silva
authors.forename: Sara Marchesan
authors.initials: SM
authors.lastname: de Oliveira
authors.forename: Juliano
authors.initials: J
authors.lastname: Ferreira
authors.forename: Roberto
authors.initials: R
authors.lastname: Andreatini
mesh_terms: D031162:Achillea; D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001007:Anxiety / Q000188:drug therapy*; D001522:Behavior, Animal / Q000187:drug effects*; D001569:Benzodiazepines / Q000494:pharmacology; D004195:Disease Models, Animal; D018682:GABA Agents / Q000494:pharmacology; D008124:Locomotion / Q000187:drug effects; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008519:Medicine, Traditional; D051379:Mice; D008815:Mice, Inbred Strains; D008517:Phytotherapy; D035261:Plant Components, Aerial; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D014151:Anti-Anxiety Agents; D018682:GABA Agents; D010936:Plant Extracts; D001569:Benzodiazepines