Inflammatory responses induced in mice by lectin from Talisia esculenta seeds

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 μg) 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 μg/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.