Mitochondrial dysfunction and targeted drugs: a focus on diabetes.

Diabetes is a severe, heterogeneous, multifactorial, chronic disease. Diabetes and oxidative stress are related to continuous and acute overproduction of reactive oxygen species (ROS). These ROS are released principally from mitochondria, but also have other sources. Oxidative stress seems to play an important role in mitochondria-mediated disease processes, though the exact molecular mechanisms responsible remain elusive. ROS are necessary for the proper functioning of the cell, but their excessive production can be harmful, making antioxidant defenses essential. Some substances with antioxidant properties, such as vitamins C and E, have been used to eradicate the oxidative stress associated with diabetes. The results of clinical trials employing anti-oxidative stress reagents in patients with diabetes are contradictory, perhaps due to inadequate study design or the specific targets selected. This review considers the process of diabetes from a mitochondrial perspective and evaluates strategies currently under development for the targeted delivery of antioxidants or other molecules to mitochondria. The evidence compiled herein endorses the selective targeting of specific molecules to mitochondria as an effective strategy for modulating mitochondrial respiration and ROS production and protecting mitochondria against oxidative stress.