, 2003). This intoxication is clinically characterized by mild depression, sleepiness, weak tremors of the head and neck muscles or discrete head nodding after exercise, severe lack of movement coordination, sideway progression and fall, hypermetria, sway while standing and wide based stance ( Medeiros et al., 2003). Previously, it was suggested that the symptoms observed upon I. asarifolia consumption were due to lysosomal storage disease ( Medeiros et al., 2000) as demonstrated for Ipomoea sericophylla and Ipomoea riedelii ( Barbosa et al., 2006). However, no evidence of such disease was found after histological or ultrastructural evaluation

this website of tissues or organs from goats experimentally intoxicated with I. asarifolia ( Medeiros et al., 2003). In addition, the presence of negligible amount of swainsonine and the absence of calystegines in the samples of I. asarifolia used in previous experiments further suggest that AT13387 the experimental intoxication induced by I. asarifolia in goats was probably not due to a storage disease ( Medeiros et al., 2003). Actually, there are few studies on I. asarifolia toxicity and the toxic substances

involved are unknown, and their mechanisms of action are not yet understood. Nevertheless, experimental evidence strongly suggested that a lectin present in the leaves of I. asarifolia could be involved in its toxic effects to goats ( Santos, 2001). Lectins are widely distributed in nature and several hundred of these molecules have been isolated from plants, viruses, bacteria, invertebrates and vertebrates, including mammals Cyclic nucleotide phosphodiesterase (Kennedy et al., 1995). Lectins are a class of proteins of non-immune origin, which possess at least one non-catalytic domain that specifically and reversibly bind to mono- or oligosaccharides (Peumans and Van Damme, 1995). A typical lectin has two or more carbohydrate-binding sites, being able to agglutinate cells. Thus they are commonly designated as agglutinins or hemagglutinins. Based on differences

in molecular structures, biochemical properties, and carbohydrate-binding specificities, plant lectins are usually considered a complex and heterogeneous group of proteins with different pharmacological and toxicological properties. This study was conducted to isolate a lectin-enriched fraction (LEF) from the leaves of I. asarifolia and assess its toxic effects on various models of study as an attempt to establish an association between this leaf lectin with the plant toxicity. I. asarifolia leaves were collected from naturally growing plants at the campus of Federal University of Ceará (UFC), Fortaleza, Brazil. A voucher specimen (registration number 040477) was deposited at Prisco Bezerra Herbarium of UFC, where it was botanically identified.