Scavenging of reactive oxygen species by a urinary preparation

In the present paper, the antioxidant properties of a preparation of human urine (PHU) were evaluated by studying the ability of this drug to react wi th relevant biological oxidants such as superoxide anion radical (O-2(-)) a nd hydroxyl radical (OH.-). In addition, its effect on lipid peroxidation w as investigated in vitro and ex vivo. PHU is not a good scavenger of O-2(-) . However, it reacts rapidly with OH.-. radicals with a second-order rate c onstant of 2.8 x 10(9)/M/sec. The studies on rat brain homogenates showed t hat PHU had an inhibitory effect, which was dependent on its concentration and the magnitude of lipid peroxidation. Ex vivo studies also showed that o ral administration of PHU increased the antioxidant capacity of plasma from rats. The ability of PHU to scavenge free radicals suggests that this drug may be potentially useful in counteracting free radical-mediated diseases.