Screening of xanthine oxidase inhibitor from selected edible plants and hypouricemic effect of Rhizoma Alpiniae Officinarum extract on hyperuricemic rats

This study was aimed at screening a potential anti-hyperuricemia agent with dual xanthine oxidase (XOD) inhibitory effect (XOI) and antioxidant activity from edible plants with health-promoting effects using nontargeted chemometric analysis (hierarchical cluster analysis and principal component analysis), evaluating its in vivo hypouricemic effect and mechanism, and identifying the key XOD inhibitor using ultrafiltration UPLC-MS/MS. Rhizoma Alpiniae Officinarum extract (GE), which has high contents of total phenolics and flavonoids, as well as dual XOI and antioxidant activity, showed significant hypouricemic and renal protective effects on hyperuricemic rats through inhibiting XOD activity, alleviating oxidative stress, down-regulating URAT1 and GLUT9 protein expression, and reducing urea nitrogen and creatinine levels. GE could be a dual-acting agent with XOI and uricosuric effect for preventing and treating hyperuricemia. Four flavonoids and eight diarylheptanoids were identified as potential XOD inhibitors from GE. Galangin, kaempferide and 3-methoxyl-galangin contributing to 70.1% of XOI were the key XOD inhibitors.