Markers of oxidative stress in erythrocytes during aging in humans.

The correlation between antioxidant capacity and oxidative damage during aging has been reported in several tissues in different species; however, data on changes of oxidative stress markers in plasma and erythrocytes of healthy populations during aging are few and sometimes contradictory. Since antioxidant capacity of the plasma is related to dietary intake of antioxidants, it is important to study the correlation between antioxidant capacity of the plasma and markers of oxidative stress in different populations. In the present study we report the age-dependent alteration in erythrocyte malondialdehyde (MDA), intracellular-reduced glutathione (GSH), and membrane sulphydryl (SH) groups in the Indian population and also correlate these parameters with total plasma antioxidant potential. We show an age-dependent increase in erythrocyte MDA level and a decrease in GSH and membrane -SH group concentration. The alterations in these parameters correlated significantly with total antioxidant capacity of the plasma. We observe a higher oxidative stress in the Indian population compared to values reported for European subjects emphasizing the need to establish age-dependent reference values for oxidative stress markers in different populations and in studies involving their role in different disease conditions.