title: Involvement of 5-HT1A in the anxiolytic-like effect of dichloromethane fraction of Pimenta pseudocaryophyllus.
abstract: BACKGROUND
  Medicinal applications of Pimenta pseudocaryophyllus infusion as a diuretic and aphrodisiac agent as well as tranquilizer in the form of tea for the treatment of emotional tension in Brazilian folk medicine has been in practice since time immemorial. Despite its popular therapeutic acceptance and claims, there are scanty scientific reports to corroborate its central biological activities.
  
  
  OBJECTIVE
  To characterize anxiolytic-like effect of the dichloromethane fraction (DF) obtained from ethanolic leaf extract of the Pimenta pseudocaryophyllus and identify mechanisms of action involved while seeking to support its popular use as a soothing agent.
  
  
  METHODS
  Mice (25-35 g) were treated orally with DF obtained from ethanolic leaf extract of Pimenta pseudocaryophyllus and were submitted to light-dark box (LDB) and elevated plus maze (EPM) tests. Different groups of mice were treated with flumazenil and NAN-190 to identify mechanisms of action involved in the anxiolytic-like effect of DF.
  
  
  RESULTS
  Treatment with DF increased number of transitions and time spent in the light compartment of the LDB while the time spent and numbers of entries in the open arm of the LCE were significantly increased. Pre-treatment of the animal with flumazenil (2 mg/kg, i.p.--competitive antagonist of benzodiazepine site of GABA(A) receptor) did not block this effect, thereby excluding participation of benzodiazepine site of the GABA(A) receptor. However, anxiolytic-like effect of DF was reversed by pre-treatment with NAN-190 (0.5 mg/kg, i.p.--an antagonist of the 5-HT(1A) receptor) thereby suggesting involvement of 5-HT(1A) receptor. The thin layer chromatography and high-performance liquid chromatography analysis indicated the predominance of (E)-methyl isoeugenol and oleanolic acid in DF.
  
  
  CONCLUSIONS
  These results support the popular use of Pimenta pseudocaryophyllus as a calming agent and suggest the involvement of 5-HT(1A) receptor.
authors.affiliation: Institute of Biological Sciences, Department of Physiological Sciences, Federal University of Goiás, Campus Samambaia, Goiânia-GO, Brazil.
authors.forename: James Oluwagbamigbe
authors.initials: JO
authors.lastname: Fajemiroye
authors.forename: Pablinny Moreira
authors.initials: PM
authors.lastname: Galdino
authors.forename: Suzana Fereirra
authors.initials: SF
authors.lastname: Alves
authors.forename: Joelma Abadia Marciano
authors.initials: JA
authors.lastname: de Paula
authors.forename: José Realino
authors.initials: JR
authors.lastname: de Paula
authors.forename: Paulo Cesár
authors.initials: PC
authors.lastname: Ghedini
authors.forename: Elson Alves
authors.initials: EA
authors.lastname: Costa
mesh_terms: D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001007:Anxiety / Q000188:drug therapy / Q000503:physiopathology*; D001522:Behavior, Animal / Q000187:drug effects; D004195:Disease Models, Animal; D000431:Ethanol / Q000737:chemistry; D005442:Flumazenil / Q000494:pharmacology; D018757:GABA Modulators / Q000494:pharmacology; D008297:Male; D008752:Methylene Chloride / Q000737:chemistry; D051379:Mice; D027841:Pimenta; D010879:Piperazines / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D018515:Plant Leaves; D044282:Receptor, Serotonin, 5-HT1A / Q000502:physiology*; D058829:Serotonin 5-HT1 Receptor Antagonists / Q000494:pharmacology; D012997:Solvents / Q000737:chemistry
chemical_list: D014151:Anti-Anxiety Agents; D018757:GABA Modulators; D010879:Piperazines; D010936:Plant Extracts; D058829:Serotonin 5-HT1 Receptor Antagonists; D012997:Solvents; D044282:Receptor, Serotonin, 5-HT1A; C058895:1-(2-methoxyphenyl)-4-(4-(2-phthalimido)butyl)piperazine; D000431:Ethanol; D005442:Flumazenil; D008752:Methylene Chloride