Rational Design of Mitochondria-Targeted Antioxidants: From Molecular Determinants to Clinical Perspectives

Oxidative stress, caused by an imbalance between the production of reactive oxygen species and endogenous antioxidant capacity, is a key etiological factor in numerous pathologies, including neurodegenerative and cardiovascular diseases. The limited clinical efficacy of conventional antioxidants is primarily due to their insufficient accumulation within the mitochondria, the main site of intracellular ROS generation. This article reviews the design and application of Mitochondria-Targeted Antioxidants, which represent a major advance in precision medicine. The design of these compounds involves linking an antioxidant “payload” to a lipophilic cation, such as the triphenylphosphonium group. This positive charge leverages the negative electrochemical gradient across the inner mitochondrial membrane to drive the antioxidant into the organelle. This mechanism allows the drug to reach concentrations over 100 times higher than non-targeted alternatives. The discussion encompasses the structure-activity analysis of the carrier, the payload (e.g., quinone derivatives), and the linker, which determine optimal subcellular partitioning and scavenging efficiency. Preclinical data highlight the therapeutic potential of this approach, showing strong neuroprotection in models of Parkinson’s and Alzheimer’s diseases, as well as improved outcomes in cardiovascular and ocular health. By restoring redox balance specifically within the mitochondria, these targeted therapies offer a more effective way to treat chronic oxidative damage.