Glycyrrhizin

Pharmacokinetics

After oral ingestion, glycyrrhizin is hydrolysed to 18β-glycyrrhetinic acid (enoxolone) by intestinal bacteria. After absorption from the gut, 18β-glycyrrhetinic acid is metabolised to 3β-monoglucuronyl-18β-glycyrrhetinic acid in the liver. This metabolite circulates in the bloodstream. Consequently, its oral bioavailability is poor. Most of it 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.

Pharmacological action

The polypharmacological effect of glycyrrhizinic acid, which has at least 12 types of activity (antitumor, hepatoprotective, immunomodulatory, antidiabetic, nephroprotective, cardioprotective, neuroprotective, atheroprotective, anti-inflammatory, antithrombotic, etc.), is closely related to its interaction with various cellular targets. Approximately 88 cellular proteins have been experimentally identified as potential targets of glycyrrhizic acid, including cytochromes P450, UDP-glucouronosyltransferases, oxidoreductases, and proteins involved in amino acid metabolism and steroid hormone biosynthesis.

Flavouring properties

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).

Adverse effects

The most widely reported side effect of glycyrrhizin use via consumption of black liquorice 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. In extreme cases, death can occur as a result of excess consumption.

References

References

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