XDH and hyperuricemia: To search for these natural products, we first used the following key words in PubMed: “uric acid” or “hyperuricemia” or “gout” and “medicinal plant” or “herb” or “herbal medicine” or “natural products” or “phytomedicine” or “phytotherapy” and “xanthine oxidase” or “XOD” or “XDH”.