INFLUENCE OF OAT SAPONINS ON INTESTINAL PERMEABILITY IN-VITRO AND IN-VIVO IN THE RAT

The aim of the present study was to investigate whether oat saponins ( avenacosides A and B) have any effect on the permeability of the rat i ntestine to actively and passively transported markers in vitro and in vivo. Intestinal segments were mounted in modified Ussing chambers, a nd the passage of the different marker compounds from the mucosal to t he serosal side was measured for 120 min. Avenacosides (1 mg/ml) gave a significantly higher passage of the macromolecule ovalbumin and ther e was a tendency to increased passage of [C-14]D-mannitol and [Cr-51]E DTA. On the other hand, the saponins did not affect the active transpo rt of [H-3]methyl glucose. When rats were given saponins (40 mg/kg bod y weight) together with markers by gastric intubation, the passage of [Cr-51]EDTA into blood and urine was somewhat reduced. For the macromo lecule bovine serum albumin, no evident effect on the passage was obse rved in the presence of saponins. Thus, in contrast to the in vitro re sults, the in vivo marker passage seemed to be unaffected or even redu ced in the presence of avenacosides. The study shows that saponins can affect the permeability of the rat intestine. However, this effect ne eds further investigation in vivo, especially regarding proteins.