title: Evidence of the involvement of the monoaminergic systems in the antidepressant-like effect of Aloysia gratissima.
abstract: BACKGROUND
  Aloysia gratissima (Verbenaceae) is an aromatic plant distributed in South America and, employed in folk medicine for the treatment of nervous systems illness, including depression. The neuroprotective and antidepressant-like activities of the aqueous extract of Aloysia gratissima (AE) administered orally has already been demonstrated.In this study the involvement of monoaminergic systems in the antidepressant-like effect of the AE was investigated.
  
  
  METHODS
  The implication of the monoaminergic systems in the antidepressant-like activity of Aloysia gratissima was evaluated using different pharmacological antagonists that were administered previously to the acute oral administration of AE (10 mg/kg). The antidepressant-like effect was assessed in the TST and locomotor activity was evaluated in the open-field test in mice.
  
  
  RESULTS
  The anti-immobility effect elicited by AE in the TST was prevented by the pre-treatment of mice with the antagonists, NAN-190 (5-HT(1A) receptor), ketanserin (5-HT(2A/2C) receptor), prazosin (α1-adrenoceptor), yohimbine (α2-adrenoceptor), SCH23390 (dopamine D1 receptor), or sulpiride (dopamine D2 receptor).
  
  
  CONCLUSIONS
  These results indicate that the antidepressant-like effect of AE in the TST is dependent on its interaction with the serotonergic (5-HT(1A) and 5-HT(2A/2C)), noradrenergic (α1 and α2-adrenoceptors) and dopaminergic (D1 and D2 receptors) systems, suggesting that this specie might act as a new potential resource for developing antidepressants to treat depressive disorders.
authors.affiliation: Departamento de Ciências Naturais, Centro de Ciências Exatas e Naturais, Universidade Regional de Blumenau, Campus I, 89012-900 SC, Brazil. anazeni@furb.br
authors.forename: Ana Lúcia B
authors.initials: AL
authors.lastname: Zeni
authors.forename: Andréa D E
authors.initials: AD
authors.lastname: Zomkowski
authors.forename: Marcelo
authors.initials: M
authors.lastname: Maraschin
authors.forename: Carla I
authors.initials: CI
authors.lastname: Tasca
authors.forename: Ana Lúcia S
authors.initials: AL
authors.lastname: Rodrigues
mesh_terms: D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology*; D001522:Behavior, Animal / Q000187:drug effects; D019417:Hindlimb Suspension; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves; D018547:Plant Stems; D017982:Receptors, Biogenic Amine / Q000037:antagonists & inhibitors / Q000502:physiology*; D029648:Verbenaceae
chemical_list: D000928:Antidepressive Agents; D010936:Plant Extracts; D017982:Receptors, Biogenic Amine
keywords: Aloysia gratissima; Antidepressant-like effect; Tail suspension test