Glycyrrhizin


Glycyrrhizin is the chief sweet-tasting constituent of Glycyrrhiza glabra root. Structurally, it is a saponin used as an emulsifier and gel-forming agent in foodstuffs and cosmetics. Its aglycone is enoxolone.

Adverse effects

The most widely reported side effect of glycyrrhizin use via consumption of black licorice is reduction of blood potassium levels, which can affect body fluid balance and function of nerves. Chronic consumption of black licorice, even in moderate amounts, is associated with an increase in blood pressure, may cause irregular heart rhythm, and may have adverse interactions with prescription drugs.

Pharmacokinetics

After oral ingestion, glycyrrhizin is first hydrolysed to 18β-glycyrrhetinic acid by intestinal bacteria. After complete absorption from the gut, 18β-glycyrrhetinic acid is metabolised to 3β-monoglucuronyl-18β-glycyrrhetinic acid in the liver. This metabolite then circulates in the bloodstream. Consequently, its oral bioavailability is poor. The main part is eliminated by bile and only a minor part by urine. After oral ingestion of 600 mg of glycyrrhizin the metabolite appeared in urine after 1.5 to 14 hours. Maximal concentrations were achieved after 1.5 to 39 hours and metabolite can be detected in the urine after 2 to 4 days.

Flavouring properties

Glycyrrhizin is obtained as an extract from licorice root after maceration and boiling in water. Licorice extract is sold in the United States as a liquid, paste, or spray-dried powder. When in specified amounts, it is approved for use as a flavor and aroma in manufactured foods, beverages, candies, dietary supplements, and seasonings. It is 30 to 50 times as sweet as sucrose.