Saponins are found in many plants. Saponins are glycosides. Like soap they lather when they are mixed with water. Soapwort has a high saponin content and can be used to make natural soap. Saponins have an expectorant effect on the body (bring up mucus from the lungs), are diuretic (elevate the rate of urination), and are said to be beneficial for the circulatory system.