Description_x000D_ General description_x000D_ Formerly E.C. 1.1.3.22_x000D_ Application_x000D_ Xanthine Oxidase from bovine milk has been used as a source for superoxide generation. It has also been used as a model enzyme in the internally calibrated electrochemical continuous enzyme assay (ICECEA)._x000D_ Packaging_x000D_ 5, 25, 50 units in poly bottle_x000D_ Biochem/physiol Actions_x000D_ The isoflavanoid genistein was shown to inhibit xanthine oxidase at concentrations between 0.1-4.0 μM and then activate xanthine oxidase at concentrations higher than 5 μM._x000D_ Xanthine Oxidase acts as a potential biomarker for oxidative stress. It is also implicated in tissue and vascular injuries such as liver damage, inflammatory diseases and chronic heart failure._x000D_ Xanthine oxidase is a molybdenum-containing enzyme that is found in the cytosol, and may be strongly inhibited by flavonoids. It plays a vital role in the metabolism of some drugs, as well as purines and pyrimidines. It is also known to be a biological source of reactive oxygen species._x000D_ Unit Definition_x000D_ One unit will convert 1.0 μmole of xanthine to uric acid per min at pH 7.5 at 25 °C. Approx. 50% of the activity is obtained with hypoxanthine as substrate._x000D_ Physical form_x000D_ Contains 0.5% sodium salicylate._x000D_ Analysis Note_x000D_ Protein determined by biuret