title: Antinociceptive and anti-inflammatory effect of the aqueous extract from leaves of Pimenta racemosa var. ozua (Mirtaceae).
abstract: The leaves of Pimenta racemosa var. ozua (Urban & Ekman) Landrum L. (Myrtaceae) are used against the pain and the inflammation in popular medicine of the Caribe area. In the present work, the antinociceptive, anti-inflammatory effect, and acute toxicity of the aqueous extract from leaves of Pimenta racemosa have been investigated. The antinociceptive action was assayed in several experimental models in mice: acetic acid, formalin, and hot plate tests. The aqueous extract (125 and 250 mg/kg) significantly and in a dose-dependent manner reduced the nociception induced by the acetic acid intraperitoneal injection (P<0.001). In the formalin test, the extract also significantly reduced the painful stimulus in both phases of the test (P<0.001). On the contrary, the extract neither significantly increased the latency time of licking nor jumping in the hot plate test. In the anti-inflammatory study, the plant also showed an interesting effect. Aqueous extract (125 and 250 mg/kg) orally administered, significantly reduced the carrageenan-induced edema in rat paw at 1, 3, and 5 h (P<0.001). In the TPA test the edema was dose-dependent and significantly reduced by the extract (0.5, 1, and 3 mg per ear) when it was topically applied (P<0.01; P<0.001). The levels of myeloperoxidase enzyme also were reduced in the inflamed tissue by the extract. Acute toxicity also was investigated and the results indicated a moderate toxicity (LD50: 287 +/- 12.9 mg residue/kg; 1.854 +/- 0.083 g plant/kg). These results revealed that the extract from leaves of Pimenta racemosa var. ozua exerts an important antinociceptive activity, associated to an anti-inflammatory effect which to appear be markedly influenced by the inhibition of neutrophil migration into inflamed tissue and that lack of toxic effects at usual doses.
authors.affiliation: Departamento de Farmacología, Facultad de Farmacia, Universidad de Sevilla, C/Profesor García González s/n, 41012, Sevilla, Spain.
authors.forename: M D
authors.initials: MD
authors.lastname: García
authors.forename: M A
authors.initials: MA
authors.lastname: Fernández
authors.forename: A
authors.initials: A
authors.lastname: Alvarez
authors.forename: M T
authors.initials: MT
authors.lastname: Saenz
mesh_terms: D000700:Analgesics / Q000302:isolation & purification / Q000627:therapeutic use*; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000302:isolation & purification / Q000627:therapeutic use*; D007249:Inflammation / Q000188:drug therapy* / Q000201:enzymology; D008297:Male; D051379:Mice; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D009195:Peroxidase / Q000378:metabolism; D008517:Phytotherapy; D027841:Pimenta; D018515:Plant Leaves; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000700:Analgesics; D000894:Anti-Inflammatory Agents, Non-Steroidal; D009195:Peroxidase