A soluble flavonoid-glycoside, αG-rutin, is absorbed as glycosides in the isolated gastric and intestinal mucosa

Abstract

We investigated the absorption and metabolism of the highly soluble quercetin glycoside αG-rutin, a glucose adduct of insoluble rutin, using the isolated mucosa of the rat stomach and intestines equipped with the Ussing chamber. αG-rutin and rutin appeared in the serosal sides of the gastric body and all the intestinal mucosa after the addition of αG-rutin (1 mM) to the mucosal fluid. The degree of αG-rutin appearance was much lower in the gastric fundus than in the other parts. Quercetin was not found in the mucosal fluid of any mucosal specimen. The concentrations (μM) of αG-rutin and rutin in the serosal fluid as a result of transport from the mucosal side increased time-dependently and linearly with mucosal αG-rutin concentration (1, 10 or 100 mM). The highest transport was shown in the ileal mucosa. These results indicate that αG-rutin is partly hydrolyzed to rutin through the intestine and absorbed as such.