Ouroboros weighs in on SkQ1 research: "Mitochondria produce rreactive oxygen species (ROS) as a byproduct of metabolism. These ROS are implicated in the mitochondrial free radical theory of aging (MFRTA) as the major cause of aging phenotypes. If the MFRTA is true, one could delay aging by removing these mitochondrially-produced ROS with enzymes or antioxidants. Although many antioxidant therapies for cancer and other age-related diseases have proved fruitless, these studies did not specifically target antioxidants to the mitochondria. One group recently did just that in mice with catalase, an antioxidant enzyme normally found in peroxisomes. By translocating catalase to the mitochondria, the scientists expanded the lifespan of the animals by five months. Such genetic manipulations such as these are not in the cards when it comes to preventing human aging. Therefore, other mitochondrial targeting strategies must be employed. Accordingly, Vladamir Skulachev's group synthesized an antioxidant attached to a positively charged ion, which they call SkQ1. This compound can readily pass through the cell membrane and travel to the mitochondrial intermembrane space, the only negatively charged region in the cell. There, SkQ1 will soak up any ROS formed by the electron transport chain. SkQ1 works similarly to the popular MitoQ, but does not have the pro-oxidant properties MitoQ is known to have at higher concentrations. SkQ1 is also better than MitoQ at inhibiting apoptosis induced by hydrogen peroxide."

Link: http://ouroboros.wordpress.com/2009/01/28/skq1-a-mitochondrially-targeted-antioxidant-that-extends-lifespan/