Effects of vitamin E on immune and inflammatory responses in rheumatic diseases

In rheumatic diseases immune and inflammatory responses result in the damage of the involved tissue. The immune response is mediated by cells of the immune system, which are activated and stimulated by vitamin E, eventually resulting in an enhanced immune reaction. The inflammatory response is associated with formation of free oxygen radicals, leading to activation of the eicosanoid cascade and the cytokine system. Liberation of arachidonic acid from membrane lipids, and its oxidative transformation to eicosanoids are inhibited by vitamin E, resulting in amelioration of the inflammatory response. Moreover, vitamin E has been shown to decrease formation of adhesion molecules, and to diminish proinflammatory signaling to the nucleus of the cell. These findings demonstrate several antiinflammatory properties of Vitamin E. Free oxygen radicals are also involved in cartilage and bone destruction in rheumatoid arthritis. Findings from animal experiments argue for an osteoprotective effect of vitamin E. Some short-term clinical studies have demonstrated an amelioration of laboratory findings and clinical symptoms in patients with rheumatic diseases during supplementation with vitamin E. Studies over prolonged periods of time are needed to evaluate the effect of vitamin E on immune and inflammatory responses, on osteodestruction and on clinical symptoms in rheumatic diseases, especially with regard to the interactions with the other antioxidants of the redox chain.