JPP 2008, 60: 771–777 © 2008 The Authors Received October 17, 2007 Accepted March 5, 2008 DOI 10.1211/jpp.60.6.0013 ISSN 0022-3573 771 Antinociceptive and anti-inflammatory effects of the essential oil from Eremanthus erythropappus leaves Orlando V. Sousa, Marcelo S. Silvério, Glauciemar Del-Vechio-Vieira, Filipe C. Matheus, Célia H. Yamamoto and Maria S. Alves Abstract The chemical composition of the essential oil from air-dried leaves of Eremanthus erythropap- pus was studied. The main compounds were b-pinene (23.24%), b-caryophyllene (22.92%), b- myrcene (10.03%) and germacrene D (9.40%). The essential oil had an LD50 of 2.90 gkg -1 in mice. Doses of 200 and 400 mgkg -1 inhibited 10.69% and 27.06% of acetic-acid-induced writh- ing in mice, respectively. In the formalin-induced nociception test in mice, the essential oil inhibited the first phase of paw licking by 29.13% (400 mgkg -1 ) and the second phase by 32.74% (200 mgkg -1 ) and 37.55% (400 mgkg -1 ). In the hot-plate test in mice, doses of 200 mgkg -1 and 400 mgkg -1 significantly increased the reaction time after 30, 60 and 90 min of treatment. Doses of 200 and 400 mgkg -1 inhibited carrageenan-induced paw oedema in rats by 15.18% and 36.61%, respectively. Doses of 200 and 400 mgkg -1 administered 4 h before intra- pleural injection of carrageenan significantly reduced exudate volume (by 20.20% and 48.70%, respectively) and leucocyte mobilization (by 5.88% and 17.29%, respectively). These results demonstrate that E. erythropappus has analgesic and anti-inflammatory properties, supporting the use of this plant in folk medicine. Essential oils are lipophilic molecules responsible for flavour and fragrance and are obtained by steam distillation (Burt 2004; Pichersky et al 2006). Most of them are mix- tures of terpene and sesquiterpene hydrocarbons, phenylpropanoids and benzenoid oxy- genated derivatives (Pichersky et al 2006). Recently, some studies have demonstrated the antinociceptive and anti-inflammatory properties of essential oils (Öztür & Özbek 2005; Lino et al 2005; Iscan et al 2006; Vendruscolo et al 2006; Passos et al 2007). These properties have been attributed to the chemical composition, such as terpinen- 4-ol (Hart et al 2000), b-caryophyllene (Passos et al 2007) and linalool and linalyl acetate (Peana et al 2002). Eremanthus erythropappus (DC) McLeisch (Asteraceae) (Vanillosmopsis erythropappa Schultz-Bip), known commonly as candeia, is used in folk medicine as an antiphlogistic and antimicrobial agent (Sousa et al 2003). The essential oil obtained from the wood of E. eryth- ropappus contains a-bisabolol, costunolide and eremanthine (Lopes et al 1991; Braun et al 2003), compounds with the cyclocostunolide and eremanthine skeleton (Lima et al 1985; Lopes et al 1991), vanillosmin (Corbrella et al 1974), 15-deoxygoyazenzolide (Vichnewski et al 1976) and lychnopholide (Vichnewski et al 1989). The a-bisabolol, present in other members of Asteraceae such as Chamomilla recutita, exhibits anti-inflammatory properties (Jakovlev et al 1979) and has been widely used in pharmaceutical and cosmetic products (Sousa et al 2003). Despite the exploration and trade of products containing essential oil from the wood of E. erythropappus, as well as chemical and biological studies, no published reports of the pharmacological and toxicological effects of the essential oil from the leaves of this species have been described. Therefore, in the present study we investigated the anti-inflammatory and analgesic effects of the essential oil obtained from E. erythropappus leaves, using a variety of different experimental models. We also established the chemical composition and acute toxicity of the essential oil studied. Introduction Departamento Farmacêutico, Faculdade de Farmácia e Bioquímica, Universidade Federal de Juiz de Fora, 36016-330, Juiz de Fora, MG, Brazil Orlando V. Sousa, Marcelo S. Silvério, Glauciemar Del-Vechio- Vieira, Filipe C. Matheus, Célia H. Yamamoto Departamento de Análises Clínicas, Faculdade de Farmácia e Bioquímica, Universidade Federal de Juiz de Fora, 36016-330, Juiz de Fora, MG, Brazil Maria S. Alves Correspondence: O. V. Sousa, Departamento Farmacêutico, Faculdade de Farmácia e Bioquímica, Universidade Federal de Juiz de Fora, 36016-330, Juiz de Fora, MG, Brazil. E-mail: orlando.sousa@ufjf.edu.br Acknowledgements and funding: We are grateful to Dr Fátima Regina Gonçalves Salimena Pires, Universidade Federal de Juiz de Fora, Minas Gerais, Brazil, for plant identification. Downloaded from https://academic.oup.com/jpp/article/60/6/771/6148040 by guest on 20 July 2022