Effect of crude extract of roots of Bredemeyera floribunda Willd. III. Effect on hormone-stimulated water transport in isolated frog skin.

The diuretic activity of the crude extract of roots of Bredemeyera floribunda Willd. (Polygalaceae) was investigated on basal and hormone-stimulated absorptive water transport in the isolated frog skin. The extract, added to the mucosal skin surface, at the peak of oxytocin (Oxy) action induces steady and dose-dependent reduction of water transport. Pre-treatment of the skins during 2 h with the extract, added to mucosal skin surface, renders the epithelium non-responsive to oxytocin. These effects are not observed when the extract is added to the serosal skin surface. Basal water transport is not altered by the extract. The results, apart from indicating inhibition of the oxytocin-stimulated water transport in frog skin epithelium, support the folk therapeutic use of infusion of the root extract as a diuretic.