title: Hyptis pectinata: redox protection and orofacial antinociception.
abstract: Hyptis pectinata L. Poit, known as 'sambacaitá', is used in Brazil to treat inflammatory and painful disorders. In this study, the antioxidant and orofacial antinociceptive properties of the aqueous extract of H. pectinata leaves (AEPH) were assessed using in vitro and in vivo models. Thus, AEPH reduced the 2,2-diphenyl-1-picrylhydrazyl radical up to 72.10% with an EC₅₀ of 14.56 µg/ml. It also inhibited 40.80% of the lipoperoxidation induced by 2'-azobis (2-amidinopropane) dihydrochloride in the thiobarbituric acid-reactive substances assay. The orofacial antinociceptive activity was evaluated in mice pre-treated with AEPH (100, 200 and 400 mg/kg, p.o.) and morphine (5 mg/kg, i.p.), which received afterwards formalin- (20 µl, 2% solution, s.c.), glutamate- (40 µl, 25 mM, s.c.) and capsaicin- (20 µl, 2.5 µg, s.c.) to induce orofacial nociception. AEPH at all doses reduced (p < 0.001) the nociceptive response in the first (43-62%) and second (47-80%) phases of the formalin test. Besides, the effect of AEPH (400 mg/kg) was not changed in the presence of naloxone (1.5 mg/kg, i.p.), an opioid antagonist. AEPH significantly inhibited mice face rubbing for capsaicin (23-69%, p < 0.05) and glutamate (48-77%, p < 0.001) at all doses. The findings suggested the AEPH has peripheral and central antinociceptive activities, which are not related to opioid receptors.
authors.affiliation: Departamento de Fisiologia, Universidade Federal de Sergipe-DFS/UFS, São Cristóvão, SE, Brazil. paixao.monicasilveira@gmail.com
authors.forename: M S
authors.initials: MS
authors.lastname: Paixão
authors.forename: M S
authors.initials: MS
authors.lastname: Melo
authors.forename: M G B
authors.initials: MG
authors.lastname: Oliveira
authors.forename: M T
authors.initials: MT
authors.lastname: Santana
authors.forename: A C B
authors.initials: AC
authors.lastname: Lima
authors.forename: N P
authors.initials: NP
authors.lastname: Damascena
authors.forename: A S
authors.initials: AS
authors.lastname: Dias
authors.forename: B S
authors.initials: BS
authors.lastname: Araujo
authors.forename: C S
authors.initials: CS
authors.lastname: Estevam
authors.forename: M A
authors.initials: MA
authors.lastname: Botelho
authors.forename: L J
authors.initials: LJ
authors.lastname: Quintans
mesh_terms: D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D001713:Biphenyl Compounds / Q000378:metabolism; D002211:Capsaicin / Q000009:adverse effects; D005157:Facial Pain / Q000188:drug therapy*; D016166:Free Radical Scavengers / Q000494:pharmacology*; D018698:Glutamic Acid / Q000009:adverse effects; D031331:Hyptis / Q000737:chemistry*; D015227:Lipid Peroxidation; D008297:Male; D051379:Mice; D009020:Morphine / Q000494:pharmacology; D010147:Pain Measurement; D010851:Picrates / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D017392:Thiobarbituric Acid Reactive Substances
chemical_list: D000700:Analgesics; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D010851:Picrates; D010936:Plant Extracts; D017392:Thiobarbituric Acid Reactive Substances; D018698:Glutamic Acid; D009020:Morphine; C004931:1,1-diphenyl-2-picrylhydrazyl; D002211:Capsaicin
keywords: DPPH; Hyptis pectinata; Lamiaceae; TBARS; antioxidant; orofacial pain