Infertility is generally defined as a partner's failure to conceive after at least 12
months off contraception and is steadily increasing worldwide. In industrialised
countries, it is estimated that around 15% of couples who wish to have a child are now
facing it, and in half of the cases, an abnormality in sperm quality or at least a male
factor is identified.
In males, the measurement of male fertility is mainly based on analyses that assess sperm
quality macroscopically (spermiogram, spermocytogram) by evaluating the number,
morphology, motility, presence of abnormalities, etc. These indicators are still
considered to be the preferred indicators for assessing male fertility.
Nevertheless, since the mid-2000s, numerous in vitro and in vivo studies in humans and
animals have shown that the integrity of sperm DNA, assessed by measuring the rate of DNA
fragmentation and chromatin decondensation in spermatozoa, could be a relevant parameter
in the etiology of male infertility. Furthermore, it has been observed that the rate of
sperm DNA fragmentation is inversely correlated with pregnancy rate, success rate of
assisted reproductive techniques and embryo quality.
The major identified cause of direct damage to DNA molecules and their possible
fragmentation, but also to proteins and cell membranes in spermatozoa is oxidative
stress. Unreduced Reactive oxygen species produced in the mitochondria-rich midpiece in
excess are susceptible to damage the DNA in the sperm head. Several exogenous factors
such as exposure to toxins, smoking, alcohol or unbalanced diet are also associated with
promoting oxidative stress.
A fragmentation rate higher than 30% is considered high, it is indicative of altered
chromatin and especially associated with a low probability of conceiving naturally or
through in vitro techniques.
To resolve this problem and improve the process of spermatogenesis and fertilisation, it
is relevant to evaluate the effectiveness of a food supplement (Isitol®), manufactured
and marketed by the company Gynov SAS (2B Rue Sauteyron - 33000 Bordeaux - France), which
provides myo-inositol and a complex with antioxidant properties based on
N-acetyl-cysteine, group B vitamins (B2, B3, B6, B9), vitamin E and zinc.
In addition to providing the nutrients that contribute to a better management of the
reactive oxygen species, the food supplement provides myo-inositol, which is essential
for the functioning of a wide range of cellular functions. This molecule, related to
glucose, is produced in the testis, mainly by Sertoli cells, and is excreted into the
seminiferous tubules as a gradient. This gradient contributes to sperm maturation by
reducing sperm viscosity and increasing sperm motility. Numerous studies evaluating the
impact of myo-inositol have shown a significant improvement in sperm parameters
(concentration, motility, morphology) and in particular in the rate of sperm DNA
fragmentation.
In order to evaluate the efficacy of this dietary supplement, a single-centre,
prospective, randomised, double-blind, interventional vs. placebo clinical study was set
up in France at Laboratoire Drouot (21 Rue Drouot - 75009 Paris - France) and directed by
Dr. Nino-Guy Cassuto. A total of 72 men aged between 20 and 45 years, with sperm DNA
fragmentation rate ≥ 30% and with negative semen culture are recruited. The recruited
patients were randomised in a 1:1 design into 2 groups (Isitol® treated vs placebo
treated).
The primary hypothesis is that after 16 (± 2) weeks of treatment with the dietary
supplement, the expected decrease in sperm DNA fragmentation rate will be ≥ 23% compared
to the placebo treated group to validate the efficacy hypothesis. The measurement of the
sperm DNA fragmentation rate is performed by TUNEL (Terminal deoxynucleotidyl transferase
dUTP (deoxyuridine triphosphate) nick end labeling) method. The secondary objectives are
the evaluation of classical sperm parameters (spermiogram, spermocytogram), sperm
morphology score, chromatin decondensation rate, sperm red/ox potential, differential
expression of 11 specific genes involved in spermatogenesis and/or at different stages of
the fertilisation process (AURKA, CCDC60, CCDC88B, etc.)).
[Results to be reported later]