No abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of coronavirus infectious disease (COVID-19) and has rapidly spread worldwide, causing serious problems to the healthcare systems of many countries and hundreds of thousand deaths. In this review we discuss data from the literature to understand whether the various districts of the male reproductive system may represent another vulnerable target for SARS-CoV-2. Studies were searched from electronic databases such as Google Scholar, PubMed, Scopus, and COVID-19 specific databases such as LitCovid, until July 31, 2021. It appears that SARS-CoV-2 virus infection not only causes damage to the respiratory system, but could have a serious impact on the reproductive system of male patients modulating many physiological processes. Like some other infections, SARS-CoV-2 also leads to a worsening of semen quality and an increase in oxidative stress (OS) levels. However, due to the limited number of studies, it is unclear whether this deterioration in semen parameters is temporary or lasts over time. It is certainly important that patients' reproductive function is monitored after coronavirus infection to avoid problems in reproductive health in the future.

Infertility affects 15% of couples worldwide. A male factor is involved in 50% of cases. The etiology of male infertility is poorly understood, but there is evidence for a strong association between oxidative stress (OS) and poor seminal fluid quality. For this reason, therapy with antioxidants is one of the cornerstones of empirical treatment of male infertility. Coenzyme Q10 (CoQ10)—an essential cofactor for energy production with major antioxidant properties—is commonly used to support spermatogenesis in idiopathic male infertility. This systematic review aims to elucidate the usefulness of CoQ10 supplementation in the treatment of male infertility, particularly with regard to semen quality assessed by conventional and advanced methods, and pregnancy rates. All studies report a beneficial effect of CoQ10 supplementation on semen parameters, although randomized controlled trials are a minority. Moreover, the optimal dosage of CoQ10 or how it can be combined with other antioxidant molecules to maximize its effect is unknown. However, CoQ10 is still one of the most promising molecules to treat idiopathic male infertility and warrants further investigation.

Erectile Dysfunction (ED) is defined as the inability to maintain and/or achieve a satisfactory erection. This condition can be influenced by the presence of atherosclerosis, a systemic pathology of the vessels that also affects the cavernous arteries and which can cause an alteration of blood flow at penile level. Among the cardiovascular risk factors affecting the genesis of atherosclerosis, hyperhomocysteinemia (HHcys) plays a central role, which is associated with oxidative stress and endothelial dysfunction. This review focuses on the biological processes that lead to homocysteine-induced endothelial damage and discusses the consequences of HHcys on male sexual function