Is There a Balance between Oxidative Stress and Antioxidant Defense System during Development?

For the reason of the biological importance of antioxidant enzymes and reactive oxygen species, it was deemed important to survey the literature for reports on the relation between them. The main aim of this overview not only uncovered the baseline works on aspects of prooxidant and antioxidant processes in different species, but also illuminated the mechanism of the free radical theory of aging. Taken together, this review suggest that the decline in levels of free radicals revealed a coupled with increased antioxidant enzyme activities and the reverse is true, but also critical balance between the generation of oxygen free radicals and antioxidant defense enzymes during development. However, these results are not still entirely accepted because of the difficulties of the direct observation of the active oxygen species in biological systems due to their short lifetime.