Reduction-oxidation (redox) state constitutes such a potential signaling mechanism for the regulation of an inflammatory signal associated with oxidative stress. Interleukin (IL)-10 has recently emerged as an anti-inflammatory cytokine with antioxidant properties. Interestingly, redox- and oxidant-mediated pathways positively and/or negatively regulate the expression, distribution, and functional properties of IL-10, thus, allowing the evolution of what is known as an anti-inflammatory redox-oxidant revolving axis. This axis is directly involved in regulating phosphorylation mechanisms, which eventually control gene expression and the biosynthesis of oxidative stress-related cofactors, such as reactive species and inflammatory cytokines. The association between IL-10, an anti-inflammatory antioxidant, with redox- and oxidant-related pathways governing the regulation of inflammatory and closely dependent processes is thereafter discussed. (C) 2002 Elsevier Science (USA). All rights reserved.