Effect of vitamin B6 on oxygen radicals, mitochondrial membrane potential, and lipid peroxidation in H2O2-treated U937 monocytes

Vitamin B-6 (Vit.B6) supplementation has been shown to be beneficial in reducing diabetic complications, cognitive aging, and in the prevention of coronary heart disease. It was hypothesized that Vit.B-6 compounds may function as antioxidants and thus offer protection against oxidative stress under various pathophysiological and or experimental conditions. To test this hypothesis, U937 monocytes were cultured with pyridoxine (P), pyridoxal phosphate (PP) and pyridoxamine (PM) and H2O2, either alone or together for 2 h. Oxidative stress was determined by measuring superoxide radical production, lipid peroxidation, and mitochondrial transmembrane potential. Results demonstrate that Vit.B-6 compounds can prevent the oxygen radical generation and lipid peroxidation caused by hydrogen peroxide in U937 monocytes, and that some of the protective effect of Vit.B-6 may occur via modification of mitochondrial function. (C) 2004 Elsevier Inc. All rights reserved.