To test this selleck compound hypothesis, we isolated a lectin-enriched fraction (LEF) from I. asarifolia leaves composed of a 44.0 kDa protein band ( Fig. 1, lane 3) that presented high

hemagglutination activity against trypsin-treated rabbit erythrocytes. The N-terminal sequence of LEF has 69%, 65%, 65% and 38% identity with the 41 kDa chloroplast nucleoid DNA-binding proteins (CND-41) of Oryza sativa subsp. Japonica, Nicotiana tabacum, Nicotiana sylvestris and Arabidopsis thaliana, respectively ( Murakami et al., 2000, Nakano et al., 1993 and Nakano et al., 1997). Nakano et al. (1997) observed that CND-41 was rare in actively photosynthesizing cells and/or tissues and suggested that CND-41 acts as a negative regulator of chloroplast gene expression. Oligomycin A chemical structure Incidentally, in this study, the leaves of I. asarifolia were kept in the dark after mechanically wounded. Our research group showed that LEF has affinity for fetuin, a glycoprotein that has sialic acid at the terminal sugar residues (Ashida et al., 2000) and for N-acetyl-d-neuramic acid (sialic acid) (Santos, 2001 and this study). Sialic acid is a component of the cell plasma membrane that modulates signal transduction particularly in gangliosides, a class of complex glycosphingolipids present in neuronal cell membranes (Mlinac and Bognar, 2010). There is evidence that sialic acids mediate specific

cellular and molecular recognition by regulating association with glycan-binding proteins such as lectins (Zhuo and Bellis, 2011). Therefore, there are potential bind sites for LEF in animal cells, especially in the neural tissue. Of particular interest is the finding that the hemagglutination C1GALT1 activity of

LEF was not abolished by the in vitro digestion with the proteolytic enzymes pepsin, trypsin and chymotrypsin. Several plant lectins are known to survive in vivo the breakdown by proteolytic enzymes and interact with cell surface sugar receptors, mediating endocytosis, an essential event that precedes cellular toxicity ( Vasconcelos and Oliveira, 2004). Thus it is possible that, in vivo, LEF binds to sialic acid bearing receptors in the goat gut cells allowing its systemic internalization and disturbance of the neural system. For instance, Ríos et al. (2008) carried out a histopathologic study that revealed the presence of cytoplasmatic vacuolation mainly in medulla oblongata and cerebellum of 1–3-year-old goats that received daily oral doses of 50 g/kg body weight of fresh leaves, flowers and stems of Ipomoea carnea, during 43–60 days. I. carnea is also a poisonous plant to cattle, sheep and goats ( Tokarnia et al., 2002). The effect of I. asarifolia upon autonomic neurotransmission has never been assessed before. In this study, inhibition of autonomic neurotransmission of mouse vas deferens by LEF indicated that this fraction has neurotoxic properties. Indeed, LEF was more effective than the leaf crude extract regarding to inhibition of autonomic neurotransmission in mouse.