Fumaric acid and its esters: an emerging treatment for multiple sclerosis with antioxidative mechanism of action.

Fumaric acid was originally therapeutically used in psoriasis. Several lines of evidence have demonstrated immunomodulatory but also neuroprotective effects for FAE. Clinical studies in psoriasis showed a reduction of peripheral CD4+ and CD8+ T-lymphocytes due to the ability of FAE to induce apoptosis. In vitro studies with the ester dimethylfumarate (DMF) described an inhibitory effect on nuclear factor kappa B (NF-κB)-dependent transcription of tumor necrosis factor-alpha (TNF-α) induced genes in human endothelial cells. Animal experiments in the mouse model of central nervous system demyelination, MOG-induced experimental autoimmune encephalomyelitis, revealed a clear preservation of myelin and axonal density in the plaque. Molecular studies showed that this is based on the antioxidative mechanism of action via induction of the transcription factor Nrf-2. A phase II clinical trial in relapsing-remitting multiple sclerosis (RRMS) patients with dimethylfumarate showed a significant reduction in the number of gadolinium enhancing lesions after 24weeks.