Soapwort is a plant with detergent cleansing properties. There is some research showing it also has antiviral and antibacterial properties.
Saponins when mixed with water reduce the surface tension of water, allowing the formation of small stable bubbles. As a consequence of their surface-active properties, saponins are excellent foaming agents (very stable). Today, saponins are used in the manufacture of fire extinguisher foam, toothpaste, shampoos, liquid soaps, and cosmetics and to increase the foaming qualities of beer and soft drinks.
Soapwort, like the other so-called “soap plants” such as soapweed (Yucca glauca), soapbark (Quillaja saponaria), and soap berries (Sapindus species), are relatively high in saponins, the substances that account for the long-lasting lather produced when parts of these plants are vigorously mixed with water. The antifungal and antibacterial properties of saponins are important in cosmetic applications, in addition to their emollient effects.
Biochemical and Biophysical Research Communications, May 1997, pages 129–132
Phytotherapy Research, 1990, volume 4, pages 97–100