title: Involvement of Cholinergic and Opioid System in γ-Terpinene-Mediated Antinociception.
abstract: The literature shows that the monoterpenes are great candidates for the development of new drugs for the treatment of various pathological processes, including painful conditions. The gamma terpinene (γ-TPN) is a monoterpene present in plant species that have multiple pharmacological properties and has structural similarity to antinociceptive monoterpenes, such as limonene and alpha-phellandrene. The γ-TPN molecular mass was evaluated by mass spectrometry and showed a pseudomolecular ion with m/z 137.0 Da. The animals did not present any signs of acute toxicity at 2 g/kg, p.o. γ-TPN (1.562 to 50 mg/kg, p.o.) showed an antinociceptive effect in the formalin, capsaicin, and glutamate tests. γ-TPN has antinociceptive action when administered by others routes in glutamate test. To eliminate a possible sedative effect of γ-TPN, the open field and rota-rod test were conducted and the γ-TPN did not show muscle relaxant activity or central depressant effect. To investigate the mechanisms of action, the animals were pretreated with naloxone, glibenclamide, atropine, mecamylamine, or L-arginine in the glutamate test. γ-TPN antinociception was inhibited in the presence of naloxone, glibenclamide, atropine, and mecamylamine. The results suggest that the γ-TPN (p.o.) produced antinociceptive effect in models of chemical nociception through the cholinergic and opioid systems involvement.
authors.affiliation: Medicinal Plants Research Center, Federal University of Piauí, Avenida Nossa Senhora de Fátima s/n, 64049-550 Teresina, PI, Brazil.
authors.forename: Flávia Franceli de Brito
authors.initials: FF
authors.lastname: Passos
authors.affiliation: Medicinal Plants Research Center, Federal University of Piauí, Avenida Nossa Senhora de Fátima s/n, 64049-550 Teresina, PI, Brazil.
authors.forename: Everton Moraes
authors.initials: EM
authors.lastname: Lopes
authors.affiliation: Medicinal Plants Research Center, Federal University of Piauí, Avenida Nossa Senhora de Fátima s/n, 64049-550 Teresina, PI, Brazil.
authors.forename: Jonas Moura
authors.initials: JM
authors.lastname: de Araújo
authors.affiliation: Department of Pharmaceutical Sciences, Federal University of Paraíba, University City, s/n, 58051-900 João Pessoa, PB, Brazil.
authors.forename: Damião Pergentino
authors.initials: DP
authors.lastname: de Sousa
authors.affiliation: Center for Research on Biodiversity and Biotechnology, Federal University of Piauí, Avenida São Sebastião, No. 2819, 64202-020 Parnaíba, PI, Brazil.
authors.forename: Leiz Maria C
authors.initials: LM
authors.lastname: Veras
authors.affiliation: Center for Research on Biodiversity and Biotechnology, Federal University of Piauí, Avenida São Sebastião, No. 2819, 64202-020 Parnaíba, PI, Brazil.
authors.forename: José Roberto S A
authors.initials: JR
authors.lastname: Leite
authors.affiliation: Medicinal Plants Research Center, Federal University of Piauí, Avenida Nossa Senhora de Fátima s/n, 64049-550 Teresina, PI, Brazil.
authors.forename: Fernanda Regina de Castro
authors.initials: FR
authors.lastname: Almeida