Vitamin C and E suppress mitogen-stimulated peripheral blood mononuclear cells in vitro.

Background/aims: The antioxidant properties of vitamin C and E are considered to be important for their anti-inflammatory activity. Recently, antioxidant resveratrol was found to suppress neopterin production and tryptophan degradation in mitogen-treated human peripheral blood mononuclear cells.

Methods: In this study, the effects of vitamin C and E were investigated in unstimulated peripheral blood mononuclear cells and in cells stimulated with the mitogens phytohaemagglutinin and concanavalin A in vitro.

Results: The mitogens induced a significant production of neopterin and a degradation of tryptophan. Vitamin C (0.1-10 microM) and E (5-100 microM) suppressed these immunobiological pathways in a dose-dependent way (p < 0.01).

Conclusion: Neopterin production and tryptophan degradation in monocyte-derived macrophages are both triggered by the pro-inflammatory cytokine interferon-gamma. Thus, their concurrent suppression by vitamin C and E suggests an effect on the formation and release of this cytokine by stimulated T cells. These findings may be related to the general health benefits which are associated with the antioxidant nature of these vitamins.