title: Analgesic effects of the ethanolic extract from Magnolia ovata (Magnoliaceae) trunk bark and of N-acetylxylopine, a semi-synthetic analogue of xylopine.
abstract: This study investigated the antinociceptive effects of the ethanolic extract (EEMO) obtained from Magnolia ovata (A.St.-Hil.) Spreng and N-acetylxylopine (AXyl), a stable derivative of xylopine in different models of nociception. The EEMO and AXyl inhibited the nociception induced by acetic acid in mice, in a dose-dependent manner with a maximal inhibition of 91 ± 9% and 50 ± 11%, respectively. Oral administration of EEMO or AXyl also significantly inhibited the inflammatory phase of formalin-induced nociception with maximal reduction of 87 ± 3.9% and 71 ± 10%, respectively. Confirming the effectiveness of the extract and the isolated compound in inflammatory responses, EEMO or AXyl inhibited carrageenan-induced mechanical allodynia with percentage of inhibition of 40 ± 6% for EEMO and 82 ± 8% for AXyl. Intraplantar injection of AXyl in the ipsilateral paw, but not in the contralateral paw, also reduced carrageenan-induced mechanical allodynia in mice. The response of the animals for maximal doses tested of EEMO and AXyl in the hot-plate or rota-rod models were not altered. These results show that the extract from M. ovata and the stable derivative AXyl possess analgesic properties towards inflammatory pain acting on peripheral sites.
authors.affiliation: Department of Pharmacology, Universidade Federal do Paraná, Curitiba, PR, Brazil.
authors.forename: Lídia Sayuri
authors.initials: LS
authors.lastname: Mori
authors.forename: Shirley
authors.initials: S
authors.lastname: Boller
authors.forename: Cândida Aparecida Leite
authors.initials: CA
authors.lastname: Kassuya
authors.forename: Maria Élida Alves
authors.initials: MÉ
authors.lastname: Stefanello
authors.forename: Aleksander Roberto
authors.initials: AR
authors.lastname: Zampronio
mesh_terms: D019342:Acetic Acid; D000700:Analgesics / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001060:Aporphines / Q000494:pharmacology / Q000627:therapeutic use*; D002351:Carrageenan; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005557:Formaldehyde; D006358:Hot Temperature; D006930:Hyperalgesia / Q000188:drug therapy*; D029562:Magnoliaceae / Q000737:chemistry*; D051379:Mice; D010146:Pain / Q000188:drug therapy*; D008517:Phytotherapy; D024301:Plant Bark; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use; D018547:Plant Stems
chemical_list: D000700:Analgesics; D000893:Anti-Inflammatory Agents; D001060:Aporphines; D010936:Plant Extracts; D005557:Formaldehyde; C062700:xylopine; D002351:Carrageenan; D019342:Acetic Acid