title: Essential oil composition and antinociceptive activity of Thymus capitatus.
abstract: BACKGROUND
  The essential oil (EO) from Thymus capitatus Hoff. et Link. (Lamiaceae) has been traditionally used for its medicinal properties, such as anti-inflammatory, analgesic, antioxidant and antimicrobial properties.
  
  
  OBJECTIVE
  Characterize the constituents from T. capitatus EO and further evaluate the antinociceptive activity by in vivo and in vitro procedures.
  
  
  METHODS
  Gas chromatography-mass spectrometry was used to identify and quantify the constituents of the T. capitatus EO. The antinociceptive activity was evaluated in vivo by the glutamate-induced nociception model in male Swiss mice (25 g), at doses of 3, 6 and 12 mg/kg, 1 h before evaluation of the licking time response (0-15 min). The mechanism of T. capitatus EO (1-500 μg/mL) on the isolated nerve excitability of Wistar rat (300 g) was assessed by the single sucrose technique.
  
  
  CONCLUSIONS
  The EO of T. capitatus presented 33 components, mainly monoterpenes and sesquiterpenes, carvacrol (ca. 80%) was its major constituent. T. capitatus EO induced antinociception in orally treated mice (3, 6, and 12 mg/kg) reducing the licking time from control (100.3 ± 11.9 s) to 84.8 ± 12.2, 62.7.6 ± 9.9, and 41.5 ± 12.7 s, respectively (n = 8; p < 0.05). Additionally, we have demonstrated that T. capitatus EO (500 μg/mL) decreased the compound action potential amplitude (VCAP) of about 80.0 ± 4.3% from control recordings (n = 4; p < 0.05). Such activity was presumably mediated through a voltage-gated Na+channels.
  
  
  CONCLUSIONS
  The present study demonstrated the antinociceptive activity of Thymus capitatus essential oil, which acts via peripheral nervous excitability blockade.
authors.affiliation: a Núcleo de Pesquisas em Plantas Medicinais, Universidade Federal do Piauí , Teresina , Brazil.|b Centro de Biotecnologia, Universidade Federal da Paraíba , João Pessoa , Brazil.
authors.forename: Juan Carlos Ramos
authors.initials: JC
authors.lastname: Gonçalves
authors.affiliation: b Centro de Biotecnologia, Universidade Federal da Paraíba , João Pessoa , Brazil.
authors.forename: Danilo Andrade
authors.initials: DA
authors.lastname: de Meneses
authors.affiliation: b Centro de Biotecnologia, Universidade Federal da Paraíba , João Pessoa , Brazil.
authors.forename: Aliny Pereira
authors.initials: AP
authors.lastname: de Vasconcelos
authors.affiliation: a Núcleo de Pesquisas em Plantas Medicinais, Universidade Federal do Piauí , Teresina , Brazil.
authors.forename: Celyane Alves
authors.initials: CA
authors.lastname: Piauilino
authors.affiliation: a Núcleo de Pesquisas em Plantas Medicinais, Universidade Federal do Piauí , Teresina , Brazil.
authors.forename: Fernanda Regina de Castro
authors.initials: FR
authors.lastname: Almeida
authors.affiliation: c Consiglio Nazionale delle Ricerche, Istituto di Chimica Biomolecolare , Catania , Italy.
authors.forename: Edoardo Marco
authors.initials: EM
authors.lastname: Napoli
authors.affiliation: c Consiglio Nazionale delle Ricerche, Istituto di Chimica Biomolecolare , Catania , Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Ruberto
authors.affiliation: b Centro de Biotecnologia, Universidade Federal da Paraíba , João Pessoa , Brazil.
authors.forename: Demetrius Antônio Machado
authors.initials: DA
authors.lastname: de Araújo
mesh_terms: D000700:Analgesics / Q000032:analysis* / Q000494:pharmacology; D000818:Animals; D004305:Dose-Response Relationship, Drug; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D008297:Male; D051379:Mice; D009822:Oils, Volatile / Q000032:analysis* / Q000494:pharmacology; D010147:Pain Measurement / Q000187:drug effects / Q000379:methods; D010938:Plant Oils / Q000032:analysis* / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D046930:Thymus Plant
chemical_list: D000700:Analgesics; D009822:Oils, Volatile; D010938:Plant Oils
keywords: Pain; action potential; glutamate