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Oxidative Medicine and Cellular Longevity 3:1, 2-12; January/February 2010; © 2010 Landes Bioscience

Markers of oxidative stress in erythrocytes and plasma during aging in humans
Kanti Bhooshan Pandey and Syed Ibrahim Rizvi*
Department of Biochemistry; University of Allahabad; Allahabad, India

ging is an inevitable universal biological process, which can becharacterized by a general decline in physiological function with the accumulation of diverse adverse changes and increased probability of death. Among several theories, oxidative stress/free radical theory offers the best mechanistic elucidation of the aging process and other age-related phenomenon. In the present paper, we discuss the aging process and have focused on the importance of some reliable markersof oxidative stress which may be used as biomarkers of the aging process. Introduction Aging is a complex progressive physiological alteration of the organism which ultimately leads to death. Observational and descriptive studies performed on a large variety of aging systems have demonstrated that the main molecular characteristic of aging is the progressive accumulation of damages inmacromolecules. Although different types of molecular damage accumulate at different rates and to different extents in different cells, the fact remains that there is a progressive increase in molecular heterogeneity with age.1 There are many ways to define aging and gerontologists are struggling for years to come to an agreement due to the complexity of the aging process. The aging process induces agerelated changes and leads to increased occurrence of many diseases. Aged individuals exhibit an inherited susceptibility to various degenerative diseases and appear less able than their young and adult counterparts to withstand physiological stress. Thus broadly, aging may be defined as an inherently complex

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process that is manifested within an organism at genetic, molecular, cellular, organand system levels.2 Although the fundamental mechanisms are still poorly understood, a growing body of evidence points toward the oxidative damage caused by reactive oxygen species (ROS) as one of the primary determinant of aging.3 A certain amount of oxidative damage takes place even under normal conditions, however the rate of this damage increases during the pathological conditions like diabetes,cardiovascular diseases and cancer.4,5 An increased oxidative stress has been linked to a shortening of life span.2,6 Free Radical/Oxidative Stress Theory of Aging There are several theories which attempt to explain the process of aging including caloric restriction, telomere theory and evolutionary theory. The oxidative stress hypothesis/free radical theory of aging proposed in 1956, updated in2006 by Harman,7,8 offers the best mechanistic elucidation of the aging process and other age-related events. ROS are produced by aerobic cells as a byproduct of their metabolic processes as well as mitochondrial respiration. These ROS exist in the cell in balance with antioxidant molecules. A condition of oxidative stress occurs when this critical balance is disrupted due to depletion ofantioxidants or excess accumulation of ROS or both i.e., when antioxidants are depleted and/or if the formation of ROS increases beyond the ability of the defenses to cope, then oxidative stress occurs and causes its detrimental

Key words: oxidative stress, human aging, biomarkers, erythrocyte, plasma Submitted: 10/26/09 Revised: 10/29/09 Accepted: 10/30/09 Previously published online:www.landesbioscience.com/journals/ oximed/article/10476
*Correspondence to: Syed Ibrahim Rizvi; Email: sirizvi@gmail.com

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Oxidative Medicine and Cellular Longevity

Volume 3 issue 1

OpiniOn paper

OpiniOn paper

Figure 1. reactive oxygen species (rOS) generated by endogenous as well as exogenous sources, cause damage and accumulation of proteins, lipids and Dnas, when defensive (repair)...