A previous study revealed the antioxidant potential of both ebselen and NAC, respectively, in human peripheral blood mononuclear cells and CD4+ T cells derived from healthy young (25–30 year olds) and older aged (55–60 year olds) donors. We observed significantly higher intracellular GSH:GSSG ratio, reduced levels of oxidative DNA damage and increased proliferative capacity in either of the antioxidant treated samples