Antidepressantlike effect of lectin from Canavalia brasiliensis (ConBr) administered centrally in mice

• Published in: Pharmacology, biochemistry and behavior biochemistry and behavior, 2006-09, Vol.85 (1), p.160-169
• Main Authors: Barauna, Sara C, Kaster, Manuella P, Heckert, Bettina T, Nascimento, Kyria Sdo, Rossi, Francesco M, Teixeira, Edson H, Cavada, Benildo S, Rodrigues, Ana Lucia S, Leal, Rodrigo B
• Format: Article
• Language: English
• ISSN: 0091-3057
• DOI: 10.1016/j.pbb.2006.07.030

This study investigates the action of the central administration of the lectins isolated from Canavalia brasiliensis seeds (ConBr) and from Canavalia ensiformes seeds, (Concanavalin A, ConA) in the forced swimming test (FST) in mice. ConBr (1-10 mu g/site, i.c.v.), but not ConA, produced a decrease in the immobility time in the FST (observed at the time points 15, 30, 60 and 120 min after the injection), without changing the locomotor activity in the openfield test. The effect of ConBr in the FST was dependent on its protein structure integrity. ConBr (0.1 mu g/site, i.c.v.) caused a potentiation of the action of fluoxetine, a selective 5HT reuptake inhibitor. The antiimmobility effect elicited by ConBr (10 mu g/site, i.c.v.) in the FST was prevented by the pretreatment of mice with pindolol (32 mg/kg, a 5HT sub(1A/1B) receptor/ beta adrenoceptor antagonist), NAN190 (0.5 mg/kg, a 5HT sub(1A) receptor antagonist), ketanserin (5 mg/kg, a 5HT sub(2A/2C) receptor antagonist), sulpiride (50 mg/kg, a D sub(2) receptor antagonist) or yohimbine (1 mg/kg, an alpha sub(2)adrenoceptor antagonist), but not with SCH 23390 (0.05 mg/kg, a D sub(1) receptor antagonist) or prazosin (1 mg/kg, an alpha sub(1)adrenoceptor antagonist). These results indicate that the antidepressantlike effect of ConBr in the FST is dependent on its interaction with the serotoninergic (via 5HT sub(1A) and 5HT sub(2)), noradrenergic (via alpha sub(2)adrenoceptors) and dopaminergic (via D sub(2) receptors) systems. Considering the presence of lectins in the brain and based on the results, it will be important to determine a possible role of endogenous lectins in the modulation of the central nervous system function.