Influence of Saponins on Gut Permeability and Active Nutrient Transport in Vitro

Abstract

The influence of four saponins, three triterpenoid glycosides and one steroidal amine glycoside, upon intestinal transport was investigated in vitro. In the presence of Gypsophylla saponin, carrier-mediated galactose transport was inhibited, although the uptake of the passively transported L-isomer of glucose increased. The uptake of the extracellular space marker, polyethylene glycol 4000, was also higher, indicating that the saponin inhibited active transport by increasing the general permeability of the enterocytes. Gypsophylla saponin, in contact only with the mucosal surface of everted jejunal sacs, induced a rapid decline in glucose-stimulated transmural potential difference. The rate of decline increased as the saponin concentration was raised over the approximate range of 0.3 to 8 mM. Saponaria saponin and alpha-tomatine also reduced transmural potential difference, but soya saponins were much less effective. The results indicate that some saponins readily increase the permeability of the small intestinal mucosal cells, thereby inhibiting active nutrient transport, and facilitating the uptake of materials to which the gut would normally be impermeable.

Use of ‘natural’ products as alternatives to antibiotic feed additives in ruminant production

“…They increase the permeability of intestinal cells through their ability to complex sterols in mucosal cell membranes (Johnson et al, 1986), which enables the uptake of non-absorbable substances (Gee et al, 1997). This property has been exploited to enhance absorption of orally administered drugs (Chao et al, 1998).…”

Local (gut) and systemic metabolism of rats is altered by consumption of raw bean (Phaseolus vulgarisL. var.athropurpurea)

“…Total phytate content was determined by ion-exchange chromatography , and total tannins by the vanillin colorimetric procedure (Deshpande & Cheryan, 1987). Total saponin content was evaluated by TLC (Johnson et al 1986). Albumin and globulin protein fractions were prepared as described previously (Carvalho, 1992;Bardocz et al 1996), analysed by SDS-PAGE (Hajos et al 1985), and lectins isolated and determined (Martinez-Aragón et al 1995;Bardocz et al 1996).…”

Effects of Saponins from the Root Bark of Aralia elata on the Transport of Chondroitin Sulfate in Caco-2 Cell Monolayers and Rats

“…Soyasaponins stimulate the uptake of [ 125 I]glycinin into rabbit jejunal mucosa in vitro, 17) and Gypsophila and Quinoa saponins increase the uptake of [ 14 C]polyethylene glycol 4000 in isolated rat jejunum. 16,18) 21) These findings suggest that saponins from plants can be used as absorption enhancers by affecting transport mechanisms in the intestinal epithelium. We have tested several kinds of saponins from Aralia elata, Panax ginseng (ginsenoside Re, Rc, and Rb 1 ), Phytolacca americana (phytolaccoside B, D 2 , E, F, G, and I), 22) and Kalopanax pictus.…”

“…Most saponins are highly surface-active and form addition-complexes with sterols, including those associated with the plasma membranes of fungi, plants and animal cells. 16) Moreover, these saponin properties can affect the integrity of biological membranes. Previous researchers have shown that saponins from different plants can facilitate the uptake of molecules not normally absorbed.…”