Evaluation of Ipomoea carnea Toxicity to Growing Goats: Clinical, Biochemical, Haematological and Pathological Alterations

摘要

Ipomoea carnea, a shrub from the Convolvulaceae family, has been incriminated as responsible for several outbreaks of livestock poisoning, mainly in goats (Tartour et al., 1974; De Balogh et al., 1999). Swainsonine, an indolizidinic alkaloid, is the most important active principle displayed by I. carnea. It promotes cellular accumulation of non-metabolized oligosaccharides due to the inhibition of acid or lysosomal enzyme alpha-mannosidase, causing cellular vacuolation. This alkaloid also inhibits Golgi mannosidase II, affecting glycoprotein synthesis, processing and transport, resulting in cellular adhesion dysfunction, in addition to hormonal changes and alterations in some membrane receptors. Ipomoea carnea also presents two other alkaloids, calistegeins C1 and B2, which inhibit beta-glycosidase (Asano et al., 1995) and because of this may aggravate swainsonine effects.