Interactions of Soybean Lectin, Soyasaponins, and Glycinin with Rabbit Jejunal Mucosa In Vitro

Abstract

SummaryMucosal samples from rabbit jejunum were incubated (30 min, 25°C) with ('251)glycinin in the presence of buffer, soybean lectin (50 pg/ml) soyasaponins (1 mglml), or both lectin and saponins.The mucosal uptake of (1251)glycinin was negligible with buffer, and increased progressively with additions of soybean lectin (P < 0.05), soyasaponins (P < 0.005), and both (P < 0.0001). The stimulation of uptake by lectin and saponins together was greater than the sum of their individual effects (P < 0.0005). The effect of soybean lectin on glycinin uptake was concentration dependent, reaching a maximum at approximately 50 pg/ml for the stimulation of uptake in the presence of saponins, and was inhibited by DGalNAc. Although the mechanisms involved in mucosal uptake of glycinin cannot be described from these data, we have assumed the presence of two independent pathways for lectin-stimulated and saponin-induced uptakes. In addition, we have proposed that soybean lectin, by binding to terminal galactoside sites at the enterocyte apical membrane, enhances a crenator effect of saponins that leads to increasing leakage of glycinin into the cell.

Food Proteins and Gut Mucosal Barrier. II. Differential Interaction of Cow's Milk Proteins with the Mucous Coat and the Surface Membrane of Adult and Immature Rat Jejunum

“…In contrast, data obtained here showed that binding of cow's milk proteins to MVM was nonspecific and weak. These food proteins did not exhibit any lectin-like characteristics as have, for instance, been shown for soy proteins (2). Use of MVM allowed for the study of newborn as well as preweanling rats.…”

Analysis, Heat Stability and Physiological Effects of Saponins from Oats

“…Thus, Johnson et al (1986) observed an increased uptake of Lglucose and polyethylene glycol 4000 in vitro in presence of Gypsophila saponins. The glycinin (a soya protein) uptake in vitro in intestine from rabbit was increased when saponins from soya was added (Alvarez and Torres-Pinedo, 1982). Increased sensitization to food allergens in rats, probably due to an increased uptake of antigens, has been demonstrated (Atkinson et al, 1994).…”

Modulation of Experimental Autoimmune Uveitis with Formosanin-C in Guinea Pigs

“…However, the mechanisms whereby formosanin-C modulates the immune system still remains unclear. The surfactant nature of saponins is considered to induce changes at the cell surface membrane (33). Selective effect of saponins to different lineages of immune cells is likely to depend on the chemical structure of the individual saponins and the nature of the cell surface.…”