Affiliations: Operative Unit of Endocrinology, Catholic University
School of Medicine, Rome, Italy | Institute of Biochemistry, Polytechnic University of
Marche, Ancona, Italy | Endocrinology, Andrology Unit, Dept of Clinical
Medicine and Applied Biotechnologies, Polytechnic University of Marche, Umberto
I Hospital, Ancona, Italy
Note: [] Address for correspondence: A. Mancini, Operative Unit of
Endocrinology, Catholic University School of Medicine, Rome, Italy. E-mail:
Mancini.giac@mclink.it
Abstract: 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 _{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.
