We had previously demonstrated that
Coenzyme Q10 [(
CoQ10) also commonly called
ubiquinone] is present in well-measurable levels in human seminal fluid, where it probably exerts important metabolic and
antioxidant functions; seminal
CoQ10 concentrations show a direct correlation with seminal parameters (count and motility). Alterations of
CoQ10 content were also shown in conditions associated with
male infertility, such as
asthenozoospermia and
varicocele (VAR). The physiological role of this molecule was further clarified by inquiring into its variations in concentrations induced by different medical or
surgical procedures used in
male infertility treatment. We therefore evaluated
CoQ10 concentration and distribution between seminal plasma and spermatozoa in VAR, before and after surgical treatment, and in infertile patients after recombinant
human FSH therapy. The effect of
CoQ10 on sperm motility and function had been addressed only through some in vitro experiments. In two distinct studies conducted by our group, 22 and 60 patients affected by idiopathic
asthenozoospermia were enrolled, respectively.
CoQ10 and its reduced form,
ubiquinol, increased significantly both in seminal plasma and sperm cells
after treatment, as well as spermatozoa motility. A weak linear dependence among the relative variations, at baseline and
after treatment, of seminal plasma or intracellular
CoQ10,
ubiquinol levels and kinetic parameters was found in the treated group. Patients with lower baseline value of motility and
CoQ10 levels had a statistically significant higher probability to be responders to the treatment. In conclusion, the exogenous administration of
CoQ10 increases both
ubiquinone and
ubiquinol levels in semen and can be effective in improving sperm kinetic features in patients affected by idiopathic
asthenozoospermia.