Oxidative stress arises in living organisms when pro-oxidant and antioxidant systems are imbalanced. It can be associated with different physiological states (fasting, physical activity, aging, etc.) and pathological processes (diseases of cardiovascular, central nervous and endocrine, respiratory system, etc.). All these diseases and physiological processes are accompanied by formation of stress in the organism. Stress is followed by stimulation of sympathetic adrenal system which causes increase of epinephrine secretion and formation of tissue hypoxia phenomena. As a consequence, the generation of free radicals in cells enhances and chain free radical processes initiate. Increasing of the free radicals level causes damage of cell components.

Oxidative stress is one of the central nonspecific components of pathogenesis of visceral diseases. Therefore, correction of its manifestations can use as non-specific approach to their treatment and prevention. The use of antioxidants nowadays becomes traditional in protecting against oxidative stress. However, the initial hopes for the effectiveness of their use for this purpose have largely failed to materialize. The use of inefficient natural and synthetic antioxidants, as well as their use in inadequate doses may be the reason for this. In this context, it seems more appropriate to increase production of native antioxidants in the organism, primarily enzymes of first line of antioxidant defense for protection against oxidative stress.

Considering the possibility of antioxidants application for protection against oxidative stress, it is necessary to pay attention to the fact that oxidative stress plays an important role in the cells adaptation to free radical damage. This effect is implemented through the stimulation of intracellular signaling pathways associated with the synthesis of antioxidant enzymes and heat shock proteins by reactive oxygen species. Therefore the suppression of this process is not justified. K. Uchida (2000) considers carbonyl products of free radical oxidation as the damaging messengers of oxidative stress.

In this regard, limitation of the negative effect of intensively generated aldehydes during stress can be considered as a fundamentally different approach to protecting against oxidative stress. For this purpose, aldehyde scavengers can be used as well as methods for increasing the rate of gene expression of enzymes catalyzing aldehyde catabolism.

Taking into account the practical importance of searching for new effective approaches to the protection from negative manifestations of oxidative stress in the development of new methods for treatment and prevention of stress-induced diseases, we dedicate a special issue of the journal to this problem.