ABSTRACT
There is considerable evidence to suggest that free radicals are a major component of many pathophysiological disorders such as ischemia/reperfusion, inflammation, and neurodegenerative diseases. In fact, oxygen-derived free radicals have been implicated in the pathology of more than 100 diseases. Cells have evolved antioxidant defense systems that serve to control the level of these reactive oxygen species. Under physiological conditions, protection is ensured by enzymes such as superoxide dismutase, catalase or gluthathione peroxidase, or by nonenzymatic mechanisms. Free-radical production has been measured directly during angioplasty reperfusion by means of electron paramagnetic resonance spectroscopy. In addition to a strong radical scavenging effect in vitro, high tissue penetration or rather tissue specificity would be needed for an antioxidant to be considered for therapeutic applications. The brain is particularly sensitive to oxidative damage because of its high concentration of polyunsaturated fatty acids and its high rate of oxygen consumption.
