Uric Acid: The Oxidant-Antioxidant Paradox

Abstract

Uric acid, despite being a major antioxidant in the human plasma, both correlates and predicts development of obesity, hypertension, and cardiovascular disease, conditions associated with oxidative stress. While one explanation for this paradox could be that a rise in uric acid represents an attempted protective response by the host, we review the evidence that uric acid may function either as an antioxidant (primarily in plasma) or pro-oxidant (primarily within the cell). We suggest that it is the pro-oxidative effects of uric acid that occur in cardiovascular disease and may have a contributory role in the pathogenesis of these conditions.

Keywords:

• Uric acid
• redox homeostasis
• metabolic syndrome
• cardiovascular disease

Supported by NIH grants HL-68607 (R. J. J.), grant from the American Heart Association 0755595B (Y. S.) and generous funds from Gatorade.

Conflict of Interest: Dr. Johnson has patent applications related to the lowering of uric acid as a means for treating cardiovascular disease and obesity via the University of Florida and University of Washington.