Saponins

Saponins are glycosides of plant origin characterized by the properties of foaming in water. Saponins are like soap in that they bond to both water and oil (grease). Many of the major tonic herbs possess saponins, including Gynostemma (gypenosides), Ginseng (ginsenosides), Astragalus (astragalosides), Eleuthero (eleutherosides), etc.