title: Chemical composition and vasorelaxant effect induced by the essential oil of Lippia alba (Mill.) N.E. Brown. (Verbenaceae) in rat mesenteric artery.
abstract: OBJECTIVE
  To investigate the chemical composition and vasorelaxant effect of the essential oil of Lippia alba (EOLA) in rat mesenteric artery.
  
  
  METHODS
  Chemical composition of EOLA was investigated by gas chromatography-mass spectrometry (GC/MS). Vasorelaxant effect was evaluated in vitro in rat superior mesenteric artery rings.
  
  
  RESULTS
  GC/MS analysis revealed the presence of 19 compounds, with geranial (48.58%) and neral (35.42%) being the major constituents. In intact rings precontracted with phenylephrine (Phe: 1 μM), EOLA (100-1000 μg/mL) induced relaxation, where the maximal effect (Emax) was 110.8 ± 10.8%. This effect was not modified after endothelium removal (Emax = 134.8 ± 16.5%), after tetraethylammonium (TEA) (Emax = 117.2 ± 4.96%), or in rings precontracted with KCl (80 mM) (Emax = 112.6 ± 6.70%). In addition, EOLA was able to inhibit the contraction caused by CaCl(2) and produced a small but significant (P<0.05) additional effect (from 70.5 ± 3.4 to 105.3 ± 13.5%, n = 5) on the maximal relaxation of nifedipine (NIF: 10 μM).
  
  
  CONCLUSIONS
  The results demonstrated that EOLA induces endothelium-independent vasorelaxation, which appears to be caused, at least in part, by blocking Ca(2+) influx through voltage-operated Ca(2+) channels.
authors.affiliation: Departamento de Fisiologia, Universidade Federal de Sergipe, São Cristóvão - SE, Brazil.
authors.forename: Luana G
authors.initials: LG
authors.lastname: Maynard
authors.forename: Kátia C
authors.initials: KC
authors.lastname: Santos
authors.forename: Patrícia S
authors.initials: PS
authors.lastname: Cunha
authors.forename: André S
authors.initials: AS
authors.lastname: Barreto
authors.forename: Magna G
authors.initials: MG
authors.lastname: Peixoto
authors.forename: Fátima
authors.initials: F
authors.lastname: Arrigoni-Blank
authors.forename: Arie F
authors.initials: AF
authors.lastname: Blank
authors.forename: Péricles B
authors.initials: PB
authors.lastname: Alves
authors.forename: Leonardo R
authors.initials: LR
authors.lastname: Bonjardin
authors.forename: Márcio R V
authors.initials: MR
authors.lastname: Santos