Toxic Responses of the Plasma Total Antioxidant Power (FRAP)

Abstract

Production of free radicals and other reactive species, including free radicals, is an integral part of human metabolism. Potentially harmful reactive oxygen species (ROS) are produced as a consequence of normal aerobic metabolism (Gutteridge 1994; Halliwell 1994). These “free radicals” are usually removed or inactivated in vivo by a team of antioxidants (Gutteridge 1994; Halliwell 1994; Halliwell and Gutteridge 1990; Frei et al. 1988, 1989). Individual members of the antioxidant defense team are deployed to prevent generation of ROS, to destroy potential oxidants, and to scavenge ROS. Thus, oxidative stress-induced tissue damage is minimized. However, an absolute or relative deficiency of antioxidant defenses may lead to a situation of increased oxidative stress, and this may be associated with both the causes and consequences of a variety of disorders, including coronary heart disease and cancer (Aruoma 1994; Knight 1995; Cheeseman and Slater 1993; Frei 1995; Schwartz et al. 1993; Cerutti 1994; Emerit 1994; Gutteridge 1995). Because of the high potential to damage vital biological systems, reactive species have now been incriminated in aging and in more than 100 disease states (Ames et al. 1993; Halliwell et al. 1992).