Hyperviscous Semen Causes Poor Sperm Quality and Male Infertility through Induction of Oxidative Stress

Abstract

Background/aims: Semen hyperviscosity (SHV) is one of the significant factors involved in poor semen quality and male infertility. It also leads major problems during assisted reproduction techniques and in vitro fertilization process. Although influence of SHV on sperm quality, fertilization rate and male infertility have been widely considered, molecular and cellular mechanisms for these abnormalities are not well understood. In this review, we aimed to discuss the proposed cellular and molecular mechanisms of SHV on male reproductive system, the importance of oxidative stress (OS) and the mechanisms by which SHV induces OS and impairment of other antioxidants.

Methods: A PubMed/Medline and EM-BASE search was performed using keywords: "hyperviscosity semen", "oxidative stress", and "male infertility".

Conclusion: OS induced by reactive oxygen species can be considered as a major mechanism in patients with hyperviscosity semen that is associated with DNA fragmentation, lipid peroxidation and sperm membrane disintegrity, apoptosis, depletion of antioxidants, and subsequently poor sperm quality and male infertility. Therefore, antioxidant therapy may improve main pathological effects of hyperviscosity semen, especially oxidative damages and inflammation, on sperm quality and function. Further, randomized controlled studies are necessary to confirm these results and make a comparison between effects of various antioxidants such as N-acethyl-cysteine and Curcumin on fertility problem in patients with hyperviscous semen.

Keywords: Antioxidants; Lipid peroxidation; Male infertility; Oxidative stress; Semen hyperviscosity.

Fig. 1

Proposed mechanisms for the effects of hyperviscous semen on poor sperm quality and male infertility. SHV decreases sperm quality and fertilization rate through several mechanisms including: impairment of sperm motility, increased number of inflammatory cytokines and leukocytes, enhanced ROS production and OS, reduced uptake of Zn, impairment of seminal plasma antioxidants, changes in some trace elements and apoptosis. OS induced by overproduction of ROS and antioxidants impairment is the major mechanism of SHV which is associated with sperm DNA oxidation, membrane lipid peroxidation, and subsequently poor sperm quality.