Screening of Uric Acid-lowering Food and Medicinal Materials Based on Inhibiting Xanthine Oxidase Activity and Zebrafish Hyperuricemia Model

Through the combination of in vitro (the xanthine oxidase inhibitory activity) and in vivo (a zebrafish hyperuricemia model) methods, the uric acid-lowering activity of 15 edible herbs crude ethanol extracts was screened. In vitro experiment set up blank group, enzyme reaction group, inhibitor group and control group. The absorbance at 295 nm with microplate reader was measured. In vivo experiment 5 days post fertilization zebrafish larvae with normal development were randomly divided into blank group, model group (200 μmol/L PO+10 μmol/L XSS), edible herbs group (200 μmol/L PO+10 μmol/L XSS+extracts of different concentrations) and positive control group (200 μmol/L PO+10 μmol/L XSS+APL 2 mmol/L). All groups were cultivated at 28.5 ℃ for 24 h to determine the uric acid contents and further verify the uric acid-lowering activity. In vitro experiment showed that 15 ethanol extracts were inhibitory, with 8 having greater than 50% inhibitory rate at 400 μm/mL. The most active one was the ethanol extracts of the Rhodiola crenulate, which was followed closely by Lagotis brevituba, Poeania suffruticosa, Patrinia scabiosaefolia, Phellodendron chinense, Scindapsus aureus, Cassia tora and Coreopsis tinctorial. In vivo experiment showed that the uric acid level of all these eight extract groups were significantly lower than the model group (P<0.05 or P<0.01).