It is well known that oxidative stress (OS), defined as an imbalance between radicals and antioxidant defense, is implicated as a pathophysiological mechanism of different diseases and is a topic of growing interest. Cell injury is a consequence of OS; recognized targets are DNA, lipids and proteins, which react with hydroxyl radicals to form specific products1. Especially in the field of cardiovascular diseases, the role of OS has been revaluated2, even if the therapeutic aftermath is still debated. Antioxidant defenses include enzymatic and
non-enzymatic molecules and they are modulated by hormones, which regulate their synthesis and turnover as previously reviewed3. CoQ10 is a lipophilic antioxidant, with a key role in energy metabolism, showing its alteration in thyroid and pituitary disorders. It is also called ubiquinone because of its ubiquitous diffusion in
organisms and tissues. It is a key component of the mitochondrial oxidative phosphorylation chain as a link between flavoproteins and cytochromes in the inner mitochondrial membrane. It also has many other functions, first of all a powerful antioxidant activity, and new roles in different cellular functions are continuously
discovered. This molecule can participate in oxido-reductive reactions in mitochondria, in lysosomes, in the Golgi apparatus and plasma membranes; it also contributes to membrane fluidity.