title: Acute effect of Copaifera reticulata Ducke copaiba oil in rats tested in the elevated plus-maze: an ethological analysis.
abstract: OBJECTIVE
  Copaiba oil oleoresin exuded from Copaifera reticulata Ducke (CRD) is commonly used in anti-inflammatory, healing and anti-tumoral folk medicines. The purpose of this study was to investigate the putative anxiolytic effect of acute administration of CRD.
  
  
  METHODS
  CRD was administered (100, 400 and 800 mg/kg, p.o.) to male Wistar rats submitted to the elevated plus-maze model of anxiety using an ethopharmacological analysis.
  
  
  RESULTS
  In comparison with control rats, CRD increased the percentage of entries in the open arms over the entire dose range tested (vehicle, 33.6 +/- 4.5; CRD 100 mg/kg, 44.67 +/- 3.68; CRD 400 mg/kg, 47.2 +/- 2.3; CRD 800 mg/kg, 50.7 +/- 2.2) and the percentage of time spent in the open arms of the elevated plus-maze at the highest dose (800 mg/kg) (vehicle, 26.4 +/- 5.7; CRD 800 mg/kg, 52.0 +/- 2.7). A standard anxiolytic, diazepam (3 mg/kg, p.o.), was used as a positive control. In a similar way, diazepam increased the percentage of entries and time spent in the open arms when compared with vehicle (% open entries: vehicle, 45.4 +/- 1.3; diazepam, 50.7 +/- 1.9; % time spent in open arms: vehicle, 28.2 +/- 0.9; diazepam, 38.9 +/- 1.2). Regarding ethological measures, CRD at the highest dose (800 mg/kg) reduced peeping out (anxiety-related behaviour) (vehicle, 3.1 +/- 0.6; CRD, 0.9 +/- 0.2) and increased end-arm activity (vehicle, 0.2 +/- 0.2; CRD, 2.0 +/- 0.4), indicating an enhanced tendency of the rats to explore actively the potentially dangerous areas of the maze. Diazepam decreased peeping out (vehicle, 3.3 +/- 0.3; diazepam, 1.0 +/- 0.2) and flat-back approach (vehicle, 0.8 +/- 0.2; diazepam, 0.2 +/- 0.1) and increased end-arm activity (vehicle, 0.3 +/- 0.1; diazepam, 2.5 +/- 0.3) and head-dipping (vehicle, 8.2 +/- 0.4; diazepam, 12.0 +/- 0.5).
  
  
  CONCLUSIONS
  These data showed, for the first time, that acute treatment with CRD copaiba oil produced a dose-dependent anxiolytic-like effect over the dose range tested, on conventional and ethological parameters, without adversely affecting general activity levels.
authors.affiliation: Laboratório de Psicologia Comparada, Departamento de Psicologia e Educação, Universidade Estácio de Sá, Nova Friburgo, Rio de Janeiro, Brazil.
authors.forename: Mateus
authors.initials: M
authors.lastname: Curio
authors.forename: Hellena
authors.initials: H
authors.lastname: Jacone
authors.forename: Jaime
authors.initials: J
authors.lastname: Perrut
authors.forename: Angelo C
authors.initials: AC
authors.lastname: Pinto
authors.forename: Valdir F Veiga
authors.initials: VF
authors.lastname: Filho
authors.forename: Regina C B
authors.initials: RC
authors.lastname: Silva
mesh_terms: D000818:Animals; D014151:Anti-Anxiety Agents / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology; D001007:Anxiety / Q000188:drug therapy*; D001453:Balsams / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D003975:Diazepam / Q000494:pharmacology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D007887:Fabaceae / Q000737:chemistry*; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D008519:Medicine, Traditional; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
chemical_list: D014151:Anti-Anxiety Agents; D001453:Balsams; C114971:copaiba balsam; D003975:Diazepam