Effect of N-acetyl cysteine supplementation on sperm quality parameters and biochemical markers on the infertile people: A systematic review on clinical trials

One of the most important factors in the development of infertility is oxidative damagewhich is mentioned by free radicals. N-acetylcysteine (NAC) is an antioxidant compound that is able to recover free radicals preventing tissue damage as well as protecting the sperm. This study aimed to summarize the data from the clinical trials in relation to the effects of NAC on oxidative stress parameters, sperm count, motility, and morphology of the sperms in the infertile men.

By searching in the scientific databases of PubMed, Google Scholar, Science Direct, Scopus, and Web of Science using the N-Acetyl-L-cysteine, NAC, Infertility, Sterility, Sub-fertility keywords, articles released between in 1990-2018 were extracted. Only clinical trials were studied and other types including cross-sectional, prospective, retrospective, overview, etc were excluded. Therefore, the inclusion criteria for this study were considered N-acetylcysteine supplementation.

NAC, as part of glutathione plays a role in restoring reserves and increasing antioxidant activity and due to its sulfidryl group it has the ability to clear free radicals by reacting with reactive oxygen species. On the other hand, increasing the production of active oxygen species due to the imbalance between peroxide and antioxidant substances on the sperm plasma membrane could have a negative effect on sperm performance.

In most studies, the positive effects of NAC supplementation on sperm parameters, antioxidant capacity, and antioxidant enzymes have been proven, but due to the shortage of studies, more trials are needed.