title: Vascular effects of Tanacetum vulgare L. leaf extract: in vitro pharmacological study.
abstract: OBJECTIVE
  Tanacetum vulgare L. (Asteraceae/Compositae) is principally used in traditional Moroccan medicine as antihypertensive remedy. The aim of the present study was to investigate the in vitro vascular activity of the aqueous extract of Tanacetum vulgare L.
  
  
  METHODS
  The activity of Tanacetum vulgare L. extract was tested on contractile response of Wistar rat aorta to high KCl and noradrenaline and on endothelium-dependent relaxation evoked by acetylcholine.
  
  
  RESULTS
  The addition of Tanacetum extract during the plateau phase of noradrenaline-evoked contraction produced a rapid relaxation that reached a maximum of 30% of the contraction and was suppressed by the NO synthase inhibitor N(G)-nitro-l-arginine. At higher extract concentrations this rapid relaxation was followed by a slowly developing, N(G)-nitro-l-arginine-resistant, relaxing effect. Tanacetum extract also depressed KCl-evoked contraction by 30% at maximum. This effect was abolished in the presence of N(G)-nitro-l-arginine. The endothelium-dependent relaxation induced by acetylcholine was depressed in the presence of Tanacetum extract in the bathing solution.
  
  
  CONCLUSIONS
  This study indicates that the aqueous extract of Tanacetum possesses NO-mediated and NO-independent vasorelaxing properties in vitro.
authors.affiliation: UFR Physiology-Pharmacology, Faculty of Sciences, Dhar-Elmahraz, Fes, Morocco.
authors.forename: Sanaa
authors.initials: S
authors.lastname: Lahlou
authors.forename: Khadija Cherkaoui
authors.initials: KC
authors.lastname: Tangi
authors.forename: Badiaâ
authors.initials: B
authors.lastname: Lyoussi
authors.forename: Nicole
authors.initials: N
authors.lastname: Morel