Study On Pharmacokinetics Of Glycyrrhizin And It's Effect On The Pharmacokinetics And Bioavailability Of Antipyrine

Glycyrrhizin, a glycoside of glycyrrhetic acid , is a major and active constituent of the root of Glycyrriza sp. (licorice) which is the most commonly used herb in traditional Chinese medicine.Glycyrrhizin possessed a variety of pharmacological effects, including anti-inflammatory, antiviral and antioxidative activities . It has been clinically used as a remedy for the treatment of chronic hepatitis and immunodeficiency virus infection. Moreover , Glycyrrhizin was recently reported to inhibit the replication of the SARS-associated viruses. However,a number of side effects including cardiac dysfunction, oedema and hypertension have been reported in subjects receiving high doses of glycyrrhizin. On the other hand, it has been noted that the liguorice extract , also containing glycyrrhizin, seems to produce fewer adverse effects than does pure glycyrrhizin.It may be attributed to the pharmacokinetic difference between pure glycyrrhizin and the liquorice extract.In this study, we compared the metabolic pharmacokinetics ofequivalent glycyrrhizin between oral administrations of pure glycyrrhizin and the licorice extract to rat. RP-HPLC methods were used for the quantitation of glycyrrhizin at different timepoints. The results indicated the areas under curves(AUC) and Cmax of glycyrrhizin after dosing with pure glycyrrhizin were markedly higher than those after dosing with the liquorice extract in rats.In our study , we also compared the pharmacokinetics and bioavailability of antipyrine after i.g. and i. p. administration of pure glycyrrhizin and the liquorice extract containing equivalent content of glycyrrhizin in mice, the results showed the ingestion of pure glycyrrhizin and the liquorice extract in mice both induced the metabolism of antipyrine, and the liquorice extract showed stronger induction effect.