Metabolic profiling of mice plasma, bile, urine and feces after oral administration of two licorice flavonones.

Abstract Ethnopharmacological relevance Licorice is an ancient food and medicinal plant. Liquiritigenin and liquiritin, two kinds of major flavonoes in licorice, are effective substances used as antioxidant, anti-inflammatory and tumor-suppressive in food, cosmetics or medicines. However, their in vivo metabolites have not been fully explored. Aim of study To clarify the metabolism of liquiritigenin and liquiritin in mice. Materials and methods In this study, we developed a liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry method to determine the metabolites in mice plasma, bile, urine and feces after oral administration of liquiritigenin or liquiritin. The structures of those metabolites were tentatively identified according to their fragment pathway, accurate mass, characteristic product ion, metabolism law and reference standard matching. Results A total of 26 and 24 metabolites of liquiritigenin or liquiritin were respectively identified. The products related with apigenin, luteolin or quercetin were the major metabolites of liquiritigenin or liquiritin in mice. Seven main metabolic pathways including (de)hydrogenation, (de)hydroxylation, (de)glycosylation, (de)methoxylation, acetylation, glucuronidation and sulfation were summarized to tentatively explain their biotransformation. Conclusion This study not only can provide the evidence for in vivo metabolites and pharmacokinetic mechanism of liquiritigenin and liquiritin, but also may lay the foundation for further development and utilization of liquiritigenin, liquiritin and then licorice.