The effect of lectin from taro tuber (Colocasia antiquorum) given by force-feeding on the growth of mice.

Abstract

SummaryIn earlier experiments in our laboratory, a lectin from the Kintoki bean (Phaseolus vulgaris) was found to have not only erythrocyte agglutinating activity but also toxicities for mice and rats, including growth inhibitory activity and even lethal activity. A number of studies on legume lectins have been carried out in other laboratories as well. But relatively little attention has been paid to lectins from non-leguminous foods. In the present study, we chose Taro tuber as a source of non-leguminous lectins and prepared two types of Taro tuber lectin. One was crude lectin precipitated with ammonium sulfate from the aqueous extract and the other was pure lectin isolated as we described previously. The two were compared with regards to the antinutritional functions in mice. The daily doses were 100mg for either intact or autoclaved crude lectin, which was a maximum amount available to give to mice in 1ml, and 30mg for the pure lectin which was equivalent to 100mg of the crude lectin in hemagglutinating activity. Control mice were given 1ml of water and the experiment was conducted for 6days. Growth retardation was found in the mice given either lectin, but no significant difference was found in the weight increase between the control group and the auto claved lectin group. For 3days during the experimental period, physical activity was measured as an index of vigor of mice. The activities of the crude lectin and the pure lectin groups leveled down to 62.9 and 64.2% of that of the control group, respectively. No apparent difference was observed in the tissue weights among the groups at the end of the experiment. Protein efficient ratio (PER) values indicated worse effi ciency of protein utilization in the lectin groups. Enzyme activities of 277

PASTA PRODUCTS CONTAINING TARO (COLOCASIA ESCULENTA L. SCHOTT) and CHAYA (CNIDOSCOLUS CHAVAMANSA L. MCVAUGH)

“…Ferredoxin has been isolated from taro. It is considered an electron carrier in the chloroplasts, containing nonheme iron, and it may contribute to the iron content in taro (Seo et al 1990). The size of the starch granules varies with the variety and ranges from 1.5 to 6.6 p. The shape is polygonal.…”