Saponins (from Latin sāpō, dop. Sāpōnis – “soap”) – a group of chemical compounds belonging to glycosides, whose molecular weight is 600-1500 u. They consist of two parts: aglycon – sapogenin (sapogenol) and gluconide – saccharide ( sugar). They are made by many plants and by some marine organisms, including sea cucumbers.
Action of saponins
They show the ability to reduce the surface tension of aqueous solutions. Foam in the water like soap (especially good in warm), which is why plant organs rich in saponins were used as a substitute for soap, for washing.
They have a therapeutic effect: diuretic, expectorant, increase mucus secretion, increase the absorption of nutrients from the intestines into the blood, anti-inflammatory, antibacterial, protozoanicidal, antifungal and antiviral, stimulate the secretion of gastric juice, bile and intestinal juice. They can affect cholesterol levels. Increase fat digestion. Some of them are poisons.
Saponins cause hemolysis of red blood cells. Saponins easily penetrate the lipid layer of the cell membrane next to the cholesterol molecules, pull cholesterol into the outer layer of the membrane, which causes the penetration of subsequent saponin molecules. The bulging and subsequent rupture of erythrocyte cell membranes occurs.
This property is used to determine the potency of saponins through the hemolytic index – the largest dilution of the saponin solution that still causes hemolysis of red blood cells.
High doses of saponins, given orally, are emetic.
Division and occurrence of saponins
• triterpene saponins – the triterpene nature of aglycone
• Steroid saponins – the steroid nature of aglycon
Saponins are most common in the skin of stems and fruits, and in roots, including plants such as:
• foam (soapstone)
• licorice smooth
• soap dish (in the roots)
• gypsophila (in the roots of several species)
• horse chestnut
• common ivy (Hedera helix)
• American knot
• chickweed (Stellaria media)
• holly (Yerba Mate)