|Trade names||Epigen, Glycyron|
|AHFS/Drugs.com||International Drug Names|
|Metabolism||Hepatic and by intestinal bacteria|
|Elimination half-life||6.2-10.2 hours|
|Excretion||Faeces, urine (0.31-0.67%)|
|E number||E958 (glazing agents, ...)|
|Chemical and physical data|
|Molar mass||822.93 g/mol|
|3D model (JSmol)|
|Solubility in water||1-10 mg/mL (20 °C)|
Glycyrrhizin (or glycyrrhizic acid or glycyrrhizinic acid) is the chief sweet-tasting constituent of Glycyrrhiza glabra (liquorice) root. Structurally, it is a saponin used as an emulsifier and gel-forming agent in foodstuffs and cosmetics. Its aglycone is enoxolone assessed as a prodrug used in Japan to reduce the risk of liver cancer in people with chronic hepatitis C.
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 adverse interactions with prescription medicines.
The effects on body fluids are related to the inhibition of cortisol metabolism within the kidney, subsequent stimulation of the mineralocorticoid receptors, and decrease in blood levels of renin, potassium, and aldosterone, which collectively lead to increases in blood pressure.
Glycyrrhizin is under laboratory and preliminary clinical research for its possible activity against common viruses, such as hepatitis C. In vitro, glycyrrhizin inhibits the enzyme 11β-hydroxysteroid dehydrogenase.
After oral ingestion, glycyrrhizin is first hydrolysed to 18β-glycyrrhetinic acid by intestinal bacteria. After complete absorption from the gut, β-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 (0.31–0.67%) by urine. After oral ingestion of 600 mg of glycyrrhizin the metabolite appeared in urine after 1.5 to 14 hours. Maximal concentrations (0.49 to 2.69 mg/l) were achieved after 1.5 to 39 hours and metabolite can be detected in the urine after 2 to 4 days.
Glycyrrhizin is obtained as an extract from licorice root after maceration and boiling in water. Licorice extract (glycyrrhizin) 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 (table sugar).
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