Antioxidants, oxidative pathology

A long-standing and fundamental problem that has frustrated attempts to directly demonstrate free radical-mediated toxicity relates to the inability to verify various reaction products seen in vivo as being derived from specific radical species. The ability of various antioxidants, such as ascorbate, tocopherol, glutathione, and cysteine, to limit or prevent injury in various models is suggestive of oxidative pathology but offers little with regard to... 

Free-radical generation occurs normally in the human body, and rates of free-radical generation are probably increased in most diseases (see Table 13.1). Their importance as a mechanism of tissue injury is still uncertain, largely because the assays used to measure them have, until recently, been primitive. The development of new assays applicable to humans (such as the assays of oxidative DNA damage described above) should allow rapid evaluation of the role of free radicals in disease pathology and provide a logical basis for the therapeutic use of antioxidants. A rationale is presented in Fig. 13.3. Attempts to use antioxidants in the treatment of human disease can be divided into three main areas ... 

In conclusion, it should be mentioned that there are numerous proposals for the application of various food products having antioxidant activity for the protection against various free radical-mediated pathologies. For example, it has been suggested that nutritional interventions such as increasing dietary intake of fruits and vegetables can decrease the age-related declines in brain functions probably via the suppression of oxidative stress [368],... 

At present, numerous free radical studies related to many pathologies have been carried out. The amount of these studies is really enormous and many of them are too far from the scope of this book. The main topics of this chapter will be confined to the mechanism of free radical formation and oxidative processes under pathophysiological conditions. We will consider the possible role of free radicals in cardiovascular disorders, cancer, anemias, inflammation, diabetes mellitus, rheumatoid arthritis, and some other diseases. Furthermore, the possibilities of antioxidant and chelating therapies will be discussed. 

Bhattacharyya, A. et al. (2007) Black tea-induced amelioration of hepatic oxidative stress through antioxidative activity in EAC-bearing mice. Journal of Environmental Pathology, Toxicology and Oncology, 26 (4), 245-254. 

Flavonoids are a family of antioxidants found in fruits and vegetables as well as in popular beverages such as red wine and tea. Although the physiological benefits of flavonoids have been largely attributed to their antioxidant properties in plasma, flavonoids may also protect cells from various insults. Nerve cell death from oxidative stress has been implicated in a variety of pathologies, including stroke, trauma, and diseases such as Alzheimer s disease and Parkinson s disease. 

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