Glycyrrhizin acid

Liquorice root Glycyrrhiza Glycyrrhizinic acid In addition to expectorant... 

Carbenoxolone derives from the hydrolysis of glycyrrhizinic acid after its extraction from licorice root. Carbenoxolone was the first drug found to accelerate peptic ulcer healing by a mechanism not involving the inhibition of acid secretion. Several mechanisms of action have been proposed as follows to explain the pharmacological activity of carbenoxolone ... 

Composite figure for the two /3-D-glucosiduronic acid groups in the glycyrrhizinic acid molecule there is, in addition, an element of non-competitive inhibition with this di-D-glucosiduronic acid. 

Glycyrrhinic acid Glycyrrhizin Glycyrrhizinic acid) (triterpene saponin) Fabaceae) [rhizome, root] CBG, CORT-R, EST-R, 11 (3HSDH, SBG) [anti-ulcerogenic, expectorant, sweet]... 

Glycyrrhizinic acid) (triterpene glycoside saponin) expectorant, sweet]... 

In healthy volunteers who took licorice corresponding to glycyrrhizinic acid 75-540 mg/day for periods of 2-4 weeks, there was an average increase in systolic blood pressure of 3.1-14.4 mmHg (34). The increase in blood pressure was dose-related and the authors concluded that as little as 50 g/day of licorice for 2 weeks would have caused a significant rise in blood pressure. 

Five patients who had consumed large amounts (0.1-1 kg) of licorice subsequently had transient visual loss/ aberrations (35). Glycyrrhizinic acid in licorice causes vasoconstriction in vascular smooth muscle and the authors therefore speculated that vasospasm of the retinal or occipital artery had caused the problems. 

In two cases prolonged intake of relatively small amounts of licorice resulted in hypertension, encephalopathy, and pseudohyperaldosteronism (37). Both patients were highly susceptible to the adverse effects of glycyrrhizinic acid because of 11-beta-hydroxysteroid dehydrogenase deficiency. 

A 67-year-old Chinese man developed progressive muscular weakness (40). His medical history was unremarkable, but his urinary potassium excretion was high and he had hypokalemia and low plasma renin activity. He admitted taking a powdered Chinese herbal formulation for about 4 months, which was shown to contain large amounts of glycyrrhizinic acid (336 mg/day). He was treated with spironolactone, and 2 weeks later his potassium values had normalized. 

A 21-year-old woman who took licorice about 100 g/day developed a headache, hypertension (190/ 120 mmHg), and hypokalemia (2.6 mmol/1). She stopped eating licorice and instead used a chewing gum that also contained licorice (daily intake of glycyrrhizinic acid about 120 mg). Three weeks after she stopped using the gum her blood pressure was 110/ 80 mmHg and plasma potassium concentration 5.3 mmol/1. 

A 35-year-old woman developed pretibial edema and hypokalemia (2.2 mmol/1) after using a licorice-flavored chewing gum (about 50 mg of glycyrrhizinic acid per day). She stopped using the gum and improved within 2 weeks. 

In six male volunteers who took glycyrrhizinic acid for 7 days, serum, urinary, and sweat electrolytes values were consistent with a mineralocorticoid-like effect (41). Plasma renin activity was suppressed, and plasma cortisol and aldosterone progressively fell during treatment. The authors proposed that glycyrrhizinic acid initially acts by increasing the effect of endogenous mineralocorticoids, and then when it or its metabolites accumulate it may also have a direct mineralocorticoid-like effect itself. 

Oral contraceptive use may increase sensitivity to glycyrrhizin acid women are reportedly more sensitive than men to adverse effects of licorice... 

Hansen H.K., Hansen S.H., Kraunspe M., Petersen GM., Comparison of high-performance liquid chromatography and capiUary electrophoresis methods for quantitative determination of glycyrrhizinic acid in pharmaceutical preparations. Eur. J. Pharm. Sci., 9,41 6 (1999). 

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