title: Antidepressant-like action of the ethanolic extract from Tabebuia avellanedae in mice: evidence for the involvement of the monoaminergic system.
abstract: The antidepressant-like effect of the ethanolic extract obtained from barks of Tabebuia avellanedae, a plant widely employed in folk medicine, was investigated in two predictive models of depression: forced swimming test (FST) and tail suspension test (TST) in mice. Additionally, the mechanisms involved in this antidepressant-like action and the effects of the association of the extract with the antidepressants fluoxetine, desipramine and bupropion in the TST were investigated. The extract from T. avellanedae produced an antidepressant-like effect, in the FST (100 mg/kg, p.o.) and in the TST (10-300 mg/kg, p.o.), without accompanying changes in ambulation when assessed in the open-field test. The anti-immobility effect of the extract (30 mg/kg, p.o.) in the TST was prevented by pre-treatment of mice with ketanserin (5 mg/kg, i.p., a preferential 5-HT(2A) receptor antagonist), prazosin (1 mg/kg, i.p., an alpha(1)-adrenoceptor antagonist), yohimbine (1 mg/kg, i.p., an alpha(2)-adrenoceptor antagonist), propranolol (2 mg/kg, i.p., a beta-adrenoceptor antagonist), sulpiride (50 mg/kg, i.p., a dopamine D(2) receptor antagonist) and SCH23390 (0.05 mg/kg, s.c., a dopamine D(1) receptor antagonist). The combined administration of a subeffective dose of WAY100635 (0.1 mg/kg, s.c., a selective 5-HT(1A) receptor antagonist) and a subeffective dose of the extract (1 mg/kg, p.o.) produced a significant reduction in the immobility time in the TST. In addition, the combination of fluoxetine (1 mg/kg, p.o.), desipramine (0.1 mg/kg, p.o.), or bupropion (1 mg/kg, p.o.) with a subeffective dose of the extract (1 mg/kg, p.o.) produced a synergistic antidepressant-like effect in the TST, without causing hyperlocomotion in the open-field test. It may be concluded that the extract from T. avellanedae produces an antidepressant-like effect in the FST and in the TST that is dependent on the monoaminergic system. Taken together, our results suggest that T. avellanedae deserves further investigation as a putative alternative therapeutic tool that could help the conventional pharmacotherapy of depression.
authors.affiliation: Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário-Trindade-88040-900, Florianópolis-SC, Brazil.
authors.forename: Andiara E
authors.initials: AE
authors.lastname: Freitas
authors.forename: Josiane
authors.initials: J
authors.lastname: Budni
authors.forename: Kelly R
authors.initials: KR
authors.lastname: Lobato
authors.forename: Ricardo W
authors.initials: RW
authors.lastname: Binfaré
authors.forename: Daniele G
authors.initials: DG
authors.lastname: Machado
authors.forename: Jardel
authors.initials: J
authors.lastname: Jacinto
authors.forename: Patrícia O
authors.initials: PO
authors.lastname: Veronezi
authors.forename: Moacir G
authors.initials: MG
authors.lastname: Pizzolatti
authors.forename: Ana Lúcia S
authors.initials: AL
authors.lastname: Rodrigues
mesh_terms: D000317:Adrenergic alpha-Antagonists / Q000627:therapeutic use; D000704:Analysis of Variance; D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology / Q000627:therapeutic use*; D015306:Biogenic Monoamines / Q000037:antagonists & inhibitors / Q000378:metabolism*; D003863:Depression / Q000188:drug therapy*; D004195:Disease Models, Animal; D015259:Dopamine Agents / Q000627:therapeutic use; D004791:Enzyme Inhibitors / Q000627:therapeutic use; D005106:Exploratory Behavior / Q000187:drug effects; D019417:Hindlimb Suspension / Q000379:methods; D046353:Immobility Response, Tonic / Q000187:drug effects; D007650:Ketanserin / Q000494:pharmacology / Q000627:therapeutic use; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D008517:Phytotherapy / Q000379:methods*; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*; D011224:Prazosin / Q000494:pharmacology / Q000627:therapeutic use; D012702:Serotonin Antagonists / Q000494:pharmacology / Q000627:therapeutic use; D013550:Swimming / Q000523:psychology; D029663:Tabebuia / Q000737:chemistry*
chemical_list: D000317:Adrenergic alpha-Antagonists; D000928:Antidepressive Agents; D015306:Biogenic Monoamines; D015259:Dopamine Agents; D004791:Enzyme Inhibitors; D010936:Plant Extracts; D012702:Serotonin Antagonists; D007650:Ketanserin; D011224:Prazosin