This review is focused upon the role of
coenzyme Q(10) in
male infertility in the light of a broader issue of oxidative damage and
antioxidant defence in sperm cells and seminal plasma.
Reactive oxygen species play a key pathogenetic role in
male infertility besides having a well-recognized physiological function. The deep involvement of
coenzyme Q(10) in mitochondrial bioenergetics and its
antioxidant properties are at the basis of its role in seminal fluid. Following the early studies addressing its presence in sperm cells and seminal plasma, the relative distribution of the
quinone between these two compartments was studied in infertile men, with special attention to
varicocele. The reduction state of
CoQ(10) in seminal fluid was also investigated. After the first in vitro experiments
CoQ(10) was administered to a group of idiopathic asthenozoospermic infertile patients. Seminal analysis showed a significant increase of
CoQ(10) both in seminal plasma and in sperm cells, together with an improvement in sperm motility. The increased concentration of
CoQ(10) in seminal plasma and sperm cells, the improvement of semen kinetic features
after treatment, and the evidence of a direct correlation between
CoQ(10) concentrations and sperm motility strongly support a cause/effect relationship. From a general point of view, a deeper knowledge of these molecular mechanisms could lead to a new insight into the so-called unexplained
infertility.