Hypouricemic and nephroprotective effects of total flavonoids from the residue of supercritical CO2 extraction of Humulus lupulus in potassium oxonate-induced mice

Total flavonoids of humulus lupulus (tfhl) were prepared using ethanol extraction,liquid-liquid partition and purification with polyamide resin. different dose of tfhl were orally administered to normal and hyperuricemic mice for 7 days. the xanthine oxidase (xod) inhibitory activity and hypouricemic effects of tfhl on potassium oxonate-induced hyperuricemic mice were examined. the tfhl showed very potent xod inhibitory activity with ic50=66.8 μg/ml. at a single oral dose of 100mg/kg tfhl,the serum uric acid levels of hyperuricemic mice significantly decreased (p<0.01) compared with a hyperuricemic control group,and the xod activity was inhibited by 22%. moreover,tfhl has a protective role against potassium oxonate-induced renal damage in mice. the results suggested that tfhl could be used as a promising drug or ingredient for treatment of hyperuricemia and gout.