Dietary intake of resveratrol enhances the adaptive immunity of aged rats.

It is well known that immune response declines with aging. Resveratrol, a polyphenol that occurs naturally in several plant species including grapevines and berries, has been shown to have potent antiaging and health-promoting activities. However, the mechanism underlying these activities remains largely unknown. Here we clearly demonstrate that: (1) Dietary intake of resveratrol induced a significant increase in T helper cells (CD4(+)) in middle-aged (12 months old) and aged (21 months old) Wistar male rats; (2) resveratrol supplementation considerably increased the delayed-type hypersensitivity response, a T cell-mediated immune response, in aged rats; and (3) reveratrol supplementation remarkably promoted the production of total anti-keyhole limpet hemocyanin (KLH) immunoglobulin G (IgG), anti-KLH IgG(1), and anti-KLH IgG(2α) in aged rats without disturbing immune homeostasis. These data together indicate that resveratrol is capable of counteracting immunosenescence, thereby leading to rejuvenation. In practice, resveratrol can be useful to help the elderly generate an improved response to vaccine with stronger humoral and cell-mediated immune responses.