Inflammatory responses induced in mice by lectin from Talisia esculenta seeds M.G.M. Freire a, * , I.A. Desouza b , A.C.M. Silva c , M.L.R. Macedo a,d , M.S. Lima c , W.M.S.C. Tamashiro e , E. Antunes b , S. Marangoni a a Departamento de Bioquı ´mica, Instituto de Biologia (IB), Universidade Estadual de Campinas (UNICAMP), Cidade Universita ´ria Zefferino Vaz, C.P. 6109, CEP 13083-970 Campinas, SP, Brazil b Departamento de Farmacologia, Faculdade de Cie ˆncias Me ´dicas (FCM), Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil c Departamento de Bioquı ´mica e Biologia Molecular, Centro de Cie ˆncias da Sau ´de, Universidade Federal do Ceara ´ (UFC), Fortaleza, CE, Brazil d Departamento de Cie ˆncias Naturais, Universidade Federal de Mato Grosso do Sul (UFMS), Tre ˆs Lagoas, MS, Brazil e Departamento de Microbiologia e Imunologia, Instituto de Biologia (IB), Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil Received 16 October 2002; accepted 5 June 2003 Abstract A novel lectin from Talisia esculenta seeds (TEL) has recently been purified and characterized. In this study we investigated the proinflammatory activity of TEL in mice using both the air-pouch and peritoneal cavity as well as paw oedema models. TEL (10–40 mg) induced significant neutrophil and mononuclear cell recruitment when injected into either mouse air-pouch or peritoneal cavity. The neutrophil accumulation into the air-pouch was dose- and time-dependent with a maximal response at 16 h, returning to control levels at 72 h whereas maximal mononuclear cell accumulation was observed at 24 h after TEL injection. The same profile of neutrophil accumulation was observed when this lectin was injected into mouse peritoneal cavity, although the maximal mononuclear cell recruitment was observed 48 h after TEL injection. Additionally, TEL (12.5 – 200 mg/paw) caused a dose-dependent mice paw, as evaluated at 4 h after the lectin injection. D-mannose, better than D- glucose, significantly inhibited TEL-induced neutrophil migration into the peritoneal cavity or air-pouch. D-galactose had no effect on TEL-induced neutrophil migration in either cavity studied. On the other hand, D-mannose slightly inhibited the TEL- induced paw oedema, whereas neither D-glucose nor D-galactose affected this phenomenon. In conclusion, our data show that TEL induces neutrophil and mononuclear cell accumulation by a mechanism related to their specific sugar-binding properties. q 2003 Elsevier Ltd. All rights reserved. Keywords: Talisia esculenta lectin; Mouse paw oedema; Leukocyte immigration 1. Introduction Plant lectins can mimic endogenous mammalian lectins, and therefore, have been widely used to study physiopatho- logical processes (Bento et al., 1993; Lima et al., 1999). The isolation and characterization of plant lectins were traditionally carried out from dry seeds of leguminous species (Chrispeels and Raikhel, 1991). More recently, the lectins have also been found in numerous other plant families (Etzler, 1986; Peumans and Van Damme, 1995, 1998). Previous studies reported that plant lectins act as potent mitogens, inducing in vitro proliferation of human lympho- cytes by cytokine-independent mechanisms (Ito et al., 1984; Borreback and Carlson, 1989). Additionally, lectins isolated from Dioclea grandiflora (Moreira et al., 1983), Canavalia 0041-0101/03/$ - see front matter q 2003 Elsevier Ltd. All rights reserved. doi:10.1016/S0041-0101(03)00142-9 Toxicon 42 (2003) 275–280 www.elsevier.com/locate/toxicon * Corresponding author. Fax: þ 55-19-37886129. E-mail address: maria.freire@terra.com.br (M.G.M. Freire).