Glycyrrhizin is a bioactive natural glycoside. Glycyrrhetic acid is an aglycone and an active metabolite of glycyrrhizin. The anti-inflammatory activity of glycyrrhetic acid is even stronger than that of glycyrrhizin and glycyrrhetic acid is responsible for the adverse effect of aldosteronism. This study attempted to compare the pharmacokinetics of glycyrrhetic acid after oral administration of equal molar doses of glycyrrhizin and glycyrrhetic acid to rabbits. Six New Zealand White rabbits were orally given glycyrrhizin or glycyrrhetic acid at a dose of 178.5 μmol kg-1 in a randomized crossover design. HPLC methods were used to determine the serum concentrations of glycyrrhizin and glycyrrhetic acid. A noncompartment model was used to calculate the pharmacokinetic parameters and a paired Student's t-test was used for statistical comparison. The results indicated that in addition to the absorption of glycyrrhizin per se at small intestine, oral dosing of glycyrrhizin resulted in higher AUC0-t, and MRT of glycyrrhetic acid by 443% and 354%, respectively, than those after oral dosing of glycyrrhetic acid. It can be concluded that glycyrrhizin is a good prodrug of glycyrrhetic acid.
Ching, H.; Hsiu, S.-L.; Hou, Y.-C.; Chen, C.-C.; and Chao, P.-D.L.
"Comparison of pharmacokinetics between glycyrrhizin and glycyrrhetic acid in rabbits,"
Journal of Food and Drug Analysis: Vol. 9
, Article 3.
Available at: https://doi.org/10.38212/2224-6614.2797