Electron transfer mediators and other metabolites and cofactors in the treatment of mitochondrial dysfunction.

Mitochondrial disorders (MDs) are caused by impairment of the mitochondrial electron transport chain (ETC). The ETC is needed for oxidative phosphorylation, which provides the cell with the most efficient energy outcome in terms of ATP production. One of the pathogenic mechanisms of MDs is the accumulation of reactive oxygen species. Mitochondrial dysfunction and oxidative stress appear to also have a strong impact on the pathogenesis of neurodegenerative diseases and cancer. The treatment of MDs is still inadequate. Therapies that have been attempted include ETC cofactors, other metabolites secondarily decreased in MDs, antioxidants, and agents acting on lactic acidosis. However, the role of these dietary supplements in the treatment of the majority of MDs remains unclear. This article reviews the rationale for their use and their role in clinical practice in the context of MDs and other disorders involving mitochondrial dysfunction.