Effect of caffeine on xanthine oxidase activity

: The effect of caffeine on the xanthine oxidase activity in human organism has been studied. It was revealed that caffeine calls the inconsiderable reliable increase of the level of uric acid and the reliable lowering of levels of hypoxanthine and xanthine in urine. The isosteric inhibition of xanthine oxidase activity by caffeine was revealed in the experiments in vitro. It was proved that caffeine cannot be the inhibitor of xantine oxidase in vivo because it demethylases to I-methylxanthine.