Hindawi Publishing Corporation Evidence-Based Complementary and Alternative Medicine Volume 2013, Article ID 715650, 9 pages http://dx.doi.org/10.1155/2013/715650 Research Article Antinociceptive and Anti�In�ammatory Activities of the Ethanolic Extract from Synadenium umbellatum Pax. (Euphorbiaceae) Leaves and Its Fractions Rodrigo Borges, 1, 2 Marcus Vinícius Mariano Nascimento, 1 Adryano Augustto Valladão de Carvalho, 1 Marize Campos Valadares, 1 José Realino de Paula, 1 Elson Alves Costa, 3 and Luiz Carlos da Cunha 1 1 Faculdade de Farmácia, Universidade Federal de Goiás, Avenida Universitária com 1a Avenida, Quadra 62, 2 Andar, Sala 36, 74605-220 Goiânia, GO, Brazil 2 Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), Avenida Nossa Senhora das Graças, 50 Xerém, Duque de Caxias, 25250-020 Rio de Janeiro, RJ, Brazil 3 Instituto de Ciências Biológicas, Universidade Federal de Goiás, Campus II-Samambaia, Saída para Nerópolis (Km 13), Caixa Postal 131, 74001-970 Goiânia, GO, Brazil Correspondence should be addressed to Luiz Carlos da Cunha; lucacunha@gmail.com Received 1 October 2012; Revised 15 December 2012; Accepted 23 December 2012 Academic Editor: Mohd Roslan Sulaiman Copyright © 2013 Rodrigo Borges et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Synadenium umbellatum Pax., popularly known in Brazil as “cola-nota,” “avelós,” “cancerola,” and “milagrosa”, is a plant species used in folk medicine for the treatment of in�ammation, pain, and several diseases. is study aimed to investigate the antinociceptive and anti-in�ammatory activities of the ethanolic extract from Synadenium umbellatum Pax. leaves (EES) and its hexane (HF), chloroform (CF), and methanol/water (MF) fractions using the acetic acid-induced abdominal writhing test, formalin-induced paw licking test, tail �ick test, croton oil-induced ear edema test, and carrageenan-induced peritonitis test. EES and MF reduced the number of acetic acid-induced abdominal writhes, while CF and HF did not. EES effect on acetic acid-induced abdominal writhing was reversed with a pretreatment with naloxone. EES reduced licking time in both phases of the formalin-induced paw licking test, but did not prolong the latency in the tail �ick test. ese results show that EES presented antinociceptive activity, probably involving the opioid system, anti-in�ammatory activity in the croton oil-induced ear edema test, and leukocyte migration into the intraperitoneal cavity. MF also presented anti-in�ammatory activity in the croton oil-induced ear edema test. In conclusion, EES and MF have antinociceptive activity involving the opioid system and anti-in�ammatory activity. 1. Introduction Medicinal plants are oen used in order to replace or assist conventional therapies in the treatment of various diseases. Among other factors, the preference for the use of medicinal plants may be related to their availability and low cost. It is known that medicinal plants have a large diversity of secondary metabolites with different biological activities [1, 2], which justi�es the research on pharmacological properties of plant species and their potential uses in drug development. Despite the preference of pharmaceutical companies for drug development using synthetic routes, in recent decades, a major concern of the market about the therapeutic potential of plants has been observed [3, 4]. is fact has been proven by the evidence that nowadays about 25% of the prescribed drugs in the world are directly or indirectly obtained from plants. In addition, approximately 49% of the drugs devel- oped between 1981 and 2002 were obtained from natural products, or similar semisynthetic or synthetic compounds based on natural products [4]. Brazil is privileged because it ranks �rst among the richest countries in biodiversity in the world, accounting for 22% of the higher plant species on the planet [5]. e immense variety of plant, animal, and microorganism species in