Can Myo-inositol in Combination With N-Acetyl-Cysteine Plus an Antioxidant Mix be Useful for the Management of Men Affected by Idiopathic Infertility and Semen Hyperviscosity?

According to the World Health Organization (WHO), the incidence of infertile couples is relatively high, with a range from 15% to 20% in the developed countries. In accordance with WHO, spermatogenesis disorders occur in almost 50% of all the cases of male infertility. In the recent decades, an unexplained reduction has been found, not only in sperm quality and quantity but also in the volume of the ejaculate. This evidence allows speculations on the number of male infertility factors, which will keep increasing in the future. An important impact on male infertility caused by environmental factors, such as bad habits (alcohol and smoking), body overload and in particular the reluctance of men undergoing prevention is widely reported. A reduced fertility is often related to a lower sperm motility. Over the recent years, the percentage of motile sperms in the ejaculate is constantly reducing. For these reasons, WHO, in the latest edition, indicated a percentage of sperms progressive motility less than 32% as a parameter of the reduced chance of getting pregnant spontaneously. The etiopathogenesis of male infertility is extremely complex, and the factors and processes causing these disorders in the reproduction are different. A common cause of reduced sperms motility seems to be related to the toxic action of reactive oxygen species (ROS). Pathological effects of free radicals in the male reproductive tract are associated with DNA fragmentation, lipid peroxidation, and apoptosis, and these lead to reduced fertility and miscarriages. Due to this evidence, antioxidant species were introduced in the management of male infertility. Between these molecules, Selenium and L-Arginine had shown a strong impact in contrasting ROS generation and restoring the oxidative status of the seminal environment. Myo-inositol (MI) is an isomer of the inositol's family. In nature are present 9 isomers of this sugar-like and MI represents the most abundant one. It plays a key role in more than one cellular pathways as FSH, insulin and TSH second intracellular messenger. It has been also demonstrated an important effect of MI in improving semen parameters such as motility, morphology, and quality, both in vitro and in vivo. From the reported studies, the effect of this isomer seems to be related to an improvement in the membrane potential of spermatozoa's mitochondria and in the reduction of the semen amorphous material that frequently impairs male fertility. Based on this evidence, recent scientific researches have been focused on the clinical use of MI in the management of male infertility caused by semen alterations. A further growing issue impairing male fertility is semen hyperviscosity (SHV). SHV is a condition that can seriously impair the physical and chemical characteristics of the seminal fluid and it can have a serious impact on sperm function. Worth of spreading, SHV seems to be associated with reduced sperm motility, possibly due to a 'trapping effect' that prevents normal sperm progression through the female genital tract. N-acetyl-L-cysteine (NAC) is a derivative of the naturally occurring amino acid L-cysteine that has free radical scavenging activity and it is also commonly used as a mucolytic agent. In addition to NAC antioxidant activity, Cifci et al. found it effective in reducing semen viscosity and its oxidative status as well as in increasing semen volume and spermatozoa motility.