Xanthine oxidase (XO), belonging to the oxidoreductase family, consists of molybdenum and iron-sulfur centers and is primarily localized in the cytoplasm of the liver and small intestine cells. It is responsible for purine metabolism, converting purines into uric acid, while also participating in the generation of reactive oxygen species and signaling pathways. The gene expression of XO is tissue-specific and regulated by various physiological and pathological conditions. Mutations in its gene may lead to excessive uric acid production, associated with gout and certain kidney diseases. Studies indicate that XO inhibitors may serve as potential drugs for treating these conditions.