title: Isolation of a dihydrobenzofuran lignan, icariside E4, with an antinociceptive effect from Tabebuia roseo-alba (Ridley) Sandwith (Bignoniaceae) bark.
abstract: The antinociceptive activity of icariside E4, a dihydrobenzofuran-type lignan isolated from Tabebuia roseo-alba (Ridley) Sandwith (Bignoniaceae) bark, was evaluated in mice by using chemical and thermal models of nociception. Intraperitoneal (i.p.) administration of crude T. roseo-alba bark extract and its methanol fraction inhibited acetic acid-induced abdominal constriction in mice. Furthermore, i.p. administration of 0.1, 1, and 10 mg/kg of icariside E4 reduced the number of writhes evoked by acetic acid injection by 46.9, 82.3, and 66.6%, respectively. Icariside E4 administration had no effect in the first phase of the formalin test, but it reduced nociceptive behavior in the second phase as indicated by a reduction in the licking time. Icariside E4 did not modify thermal nociception in the hot-plate test model, suggesting that it had a peripheral antinociceptive action. The antinociceptive effect of icariside E4 in the writhing test was reversed by pre-administration of glibenclamide, but not of naloxone, atropine, yohimbine, or haloperidol. Together, these results indicated that the antinociceptive activity of icariside E4 from T. roseo-alba in models of chemical pain occurred through ATP-sensitive K(+) channel-dependent mechanisms.
authors.affiliation: Instituto de Química e Biotecnologia, Universidade Federal de Alagoas, Maceió-AL, 57072-970, Brazil.
authors.forename: Jesu C
authors.initials: JC
authors.lastname: Ferreira-Júnior
authors.forename: Lucia M
authors.initials: LM
authors.lastname: Conserva
authors.forename: Rosangela P
authors.initials: RP
authors.lastname: Lyra Lemos
authors.forename: Genilda C
authors.initials: GC
authors.lastname: de Omena-Neta
authors.forename: Araken
authors.initials: A
authors.lastname: Cavalcante-Neto
authors.forename: Emiliano
authors.initials: E
authors.lastname: Barreto
mesh_terms: D019342:Acetic Acid; D000700:Analgesics / Q000302:isolation & purification* / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005557:Formaldehyde; D006027:Glycosides / Q000302:isolation & purification* / Q000494:pharmacology*; D006358:Hot Temperature; D007274:Injections, Intraperitoneal; D054086:KATP Channels / Q000187:drug effects; D017705:Lignans / Q000302:isolation & purification* / Q000494:pharmacology*; D008297:Male; D051379:Mice; D010146:Pain / Q000139:chemically induced / Q000188:drug therapy; D010147:Pain Measurement; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D029663:Tabebuia / Q000737:chemistry*
chemical_list: D000700:Analgesics; D006027:Glycosides; D054086:KATP Channels; D017705:Lignans; D010936:Plant Extracts; C000605636:icariside E4; D005557:Formaldehyde; D019342:Acetic Acid