Related Experiment Video
Updated: Jun 22, 2025

Inner Mitochondrial Membrane Sensitivity to Na+ Reveals Partially Segmented Functional CoQ Pools
Published on: July 20, 2022
The Ubiquinone-Ubiquinol Redox Cycle and Its Clinical Consequences: An Overview
David Mantle1, Mollie Dewsbury2, Iain P Hargreaves2
1Pharma Nord (UK) Ltd., Morpeth NE61 2DB, UK.
Abstract:
Coenzyme Q10 (CoQ10) plays a key role in many aspects of cellular metabolism. For CoQ10 to function normally, continual interconversion between its oxidised (ubiquinone) and reduced (ubiquinol) forms is required. Given the central importance of this ubiquinone-ubiquinol redox cycle, this article reviews what is currently known about this process and the implications for clinical practice. In mitochondria, ubiquinone is reduced to ubiquinol by Complex I or II, Complex III (the Q cycle) re-oxidises ubiquinol to ubiquinone, and extra-mitochondrial oxidoreductase enzymes participate in the ubiquinone-ubiquinol redox cycle. In clinical terms, the outcome of deficiencies in various components associated with the ubiquinone-ubiquinol redox cycle is reviewed, with a particular focus on the potential clinical benefits of CoQ10 and selenium co-supplementation.
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