Determination of Glycyrrhetic Acid in Rat Plasma by HPLC After Oral Administration of Licorice Aqueous Extract

Abstract

Licorice is obtained from <em>Glycyrrhiza glabra</em> (<em>G. glabra</em>) in Iran. Glycyrrhizin is the main constituent of <em>G. glabra</em> and has several pharmacological effects. It is hydrolyzed to glycyrrhetic acid (GA) in the intestine after oral administration. In this study, a novel HPLC method was used to determine the concentration of GA in rat plasma after oral administration of licorice aqueous extract. The method was linear (r² >0.999) in the range of 0.1-5.0 μg/ml for GA. Maximum plasma concentration of GA was achieved 8 h after oral administration of licorice aqueous extract. The developed method was suitable for determination of GA in rat plasma.