title: Evidence of the mechanism of action of Erythrina velutina Willd (Fabaceae) leaves aqueous extract.
abstract: BACKGROUND
  Erythrina velutina is traditionally used for sleepiness, convulsions and nervous system excitation in Brazil. Although central effects have been reported for Erythrina velutina, little is known about its mechanism of action.
  
  
  OBJECTIVE
  To investigate the pharmacological evidences of mechanism of action of Erythrina velutina leaves aqueous extract (AE).
  
  
  METHODS
  Terminal segments of the guinea-pig ileum (n=5-8) were mounted in an organ bath and isotonic contractions were recorded. Phytochemical screening was carried out on AE.
  
  
  RESULTS
  AE (0.025-2.50 mg/ml) produced contractile response in the guinea-pig ileum, yielding typical concentration-response curves (EC50=0.63 mg/ml). Electrically evoked contractions were significantly increased in the presence of AE. AE-elicited contractions were significantly reduced by bicuculline, tetrodotoxin, atropine, verapamil or incubation in low calcium-high potassium solution. Atropine along with verapamil abolished AE contractile response. Alkaloids, catechins, steroids, flavonols, flavononols, flavonoids, phenols, saponins, tannins, triterpenoids, and xanthones were detected in AE.
  
  
  CONCLUSIONS
  AE contains important constituents for pharmacological activities. AE-induced contractions seem to involve GABAA receptor activation, acetylcholine release, muscarinic receptor activation, augmentation of Ca2+ entry through L-type calcium channels, and calcium release from the intracellular stores. These findings provide further support for Erythrina velutina traditional uses.
authors.affiliation: Pharmacology Research Laboratory, Physiology Department, Federal University of Sergipe, Av Marechal Rondon, s/n, São Cristóvão, Sergipe, 49.100-000, Brazil.
authors.forename: Ana Carla C S
authors.initials: AC
authors.lastname: Carvalho
authors.forename: Dayse S
authors.initials: DS
authors.lastname: Almeida
authors.forename: Marcélia G D
authors.initials: MG
authors.lastname: Melo
authors.forename: Sócrates C H
authors.initials: SC
authors.lastname: Cavalcanti
authors.forename: Rosilene M
authors.initials: RM
authors.lastname: Marçal
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D004895:Erythrina; D005260:Female; D018756:GABA Antagonists / Q000494:pharmacology; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects / Q000502:physiology; D008297:Male; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects* / Q000502:physiology; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018515:Plant Leaves; D026941:Sodium Channel Blockers / Q000494:pharmacology
chemical_list: D002121:Calcium Channel Blockers; D018756:GABA Antagonists; D018727:Muscarinic Antagonists; D010936:Plant Extracts; D026941:Sodium Channel Blockers; D002118:Calcium