We report that incorporation of very low concentrations of redox protein cytochrome c and redox active small molecule vitamin C impacted the outcome of one-electron oxidations mediated by structurally distinct plant/fungal heme peroxidases. Evidence suggests that cytochrome c and vitamin C function as a redox relay for diffusible reduced oxygen species in the reaction system, without invoking specific or affinity-based molecular interactions for electron transfers. The findings provide novel perspectives to understanding - (1) the promiscuous role of cytochrome 65 in the metabolism mediated by liver microsomal xenobiotic metabolizing systems and (2) the roles of antioxidant molecules in affording relief from oxidative stress. (C) 2012 Elsevier Inc. All rights reserved.