Vasodilator effects of Diocleinae lectins from the Canavalia genus

Abstract

This study investigated and compared vascular actions of leguminous lectins obtained from the Canavalia genus (Canavalia brasiliensis, Canavalia gladiata, and Canavalia maritima) in the rat models of paw edema and isolated aorta. Paw edema was induced by subcutaneous injection of lectins (0.01-1 mg/kg) in animals pre-treated or not with indomethacin or L-NAME. In isolated aorta, cumulative concentration curves of C. gladiata or C. brasiliensis (1-100 microg/ml) were performed at the contraction plateau induced by phenylephrine or at tissue basal tonus. The mechanism of the lectin relaxant action was investigated by previous addition of L-NAME, indomethacin, or tetraethylammonium. In both models, the lectin domain involvement was evaluated by incubation of lectins with their ligand and non-ligand sugars. The lectins induced paw edema paralleled by protein leakage. The edematogenic activity elicited by C. gladiata and C. brasiliensis involves prostaglandins and nitric oxide (NO), while that of C. maritima occurs without NO interference. C. gladiata and C. brasiliensis elicited aorta relaxation involving NO and prostacyclin, while that of C. gladiata included EDHF. All lectin effects were prevented by their binding sugars. The present study demonstrated important vasodilator effects of different degrees and mechanisms in vivo and in vitro of Canavalia lectins. In vivo, the edematogenic activity was paralleled by plasma exudation, and in vitro, aorta relaxation was strictly dependent on intact endothelium. All effects occurred via interaction with lectin domains and participation of NO and/or prostanoids.

Purification, characterization and partial sequence of a pro‐inflammatory lectin from seeds of Canavalia oxyphylla Standl. & L. O. Williams

“…The edematogenic effect elicited by CoxyL was characteristic of acute inflammatory responses. Similar responses had been previously shown for the lectin isolated from Canavalia maritma seeds, in which the edematogenic effect lasted 300 min, while the edematogenic effect induced by ConBr and CGL was more lasting, about 32 h, compared with CoxyL (Assreuy et al ., ). These data are in line with other reports that highlights the relation structure and biological activities of these homologous lectins (Barral‐Netto et al ., ; Calvete et al ., ; Gadelha et al ., ; Cavada et al ., 2011).…”

Purification and partial characterization of a novel lectin from Dioclea lasiocarpa Mart seeds with vasodilator effects

“…The relaxation induced by DLL effect was found to be strictly dependent on the intact endothelium and highlighted the importance of the lectins carbohydrate‐binding sites. A variety of lectin elicited endothelium dependent relaxation in aorta with participation of NO that was reversed by their binding sugars: the algae lectins from Bryothaminium triquetrum (Lima et al ., ) and Bryothamnion seaforthii (Lima et al ., ) and the plant lectins from Canavalia genus (Gadelha et al ., ; Assreuy et al ., ) and from Dioclea virgata (Nóbrega et al ., ).…”

Vascular Smooth Muscle Relaxation by a Lectin from Pisum arvense: Evidences of Endothelial NOS Pathway

“…On the other hand, prostacyclin and NO increase intracellular concentrations of AMPc e GMPc respectively, initiating the biochemical pathway that leads to signal transduction [11,21]. These data strongly suggest the participation of NO in the relaxant effect of PAL, as shown for other leguminous lectins [4][5]. These data strongly suggest the participation of NO in the relaxant effect of PAL, as shown for other leguminous lectins [4][5].…”

“…The involvement of carbohydrate recognition sites was already demonstrated for other plant lectins [4][5][15][16][17]. The involvement of carbohydrate recognition sites was already demonstrated for other plant lectins [4][5][15][16][17].…”