Despite previous reports of anti-aging effects of Korean red ginseng (KRG), the underlying mechanisms remain poorly understood. Therefore, this study investigated possible mechanisms of KRG-mediated anti-aging effects in aged mice. KRG significantly inhibited thymic involution in old mice. Interestingly, KRG only increased protein expression, but not mRNA expression, of aging-related genes Lin28a, GDF-11, Sirt1, IL-2, and IL-17 in the thymocytes of old mice. KRG also modulated the population of some types of immune cells in old mice. KRG increased the population of regulatory T cells and interferon-gamma (IFN-γ)-expressing natural killer (NK) cells in the spleen of old mice, but serum levels of regulatory T cell-specific cytokines IL-10 and TGF-β were unaffected. Finally, KRG recovered mRNA expression of Lin28a, GDF-11, and Sirt1 artificially decreased by concanavalin A (Con A) in both thymocytes and splenocytes of old mice without cytotoxicity. These results suggest that KRG exerts anti-aging effects by preventing thymic involution, as well as modulating the expression of aging-related genes and immune cell subsets.
Keywords: aging-related genes; anti-aging; immune cell population; korean red ginseng; thymic involution.