Identification of anti-hyperuricemic components from Cichorium intybus L. taproots

Chicory (Cichorium intybus L.) is a worldwide cultivated plant with the anti-hyperuricemic effect. In this study, the anti-hyperuricemic effect was evaluated using an acute hyperuricemia mouse model to screen out anti-hyperuricemic components of chicory aqueous extract. The effective components significantly reduced serum uric acid levels by inhibiting liver xanthine oxidase (XOD) activity and alleviated kidney injury in hyperuricemia mice. Six compounds, including three chlorogenic acid isomers, were yielded through the column chromatographic isolation of the effective components, and their structures were identified by nuclear magnetic resonance spectroscopy. Among them, chlorogenic acid methyl ester was first isolated from chicory. Cryptochlorogenic acid exhibited XOD inhibitory activity in vitro, with IC50 = 83.86 μg/mL. Because of the different substitution positions of the caffeoyl group and the number of methyl groups, chlorogenic acid isomers had different binding affinities and sites with XOD, showing different XOD inhibitory activities in vitro. This study revealed anti-hyperuricemic compounds of chicory, which helped clarify the material basis of chicory in the prevention and treatment of hyperuricemia.