Evaluation of Sperm Mitochondrial Function: A Key Organelle for Sperm Motility

Abstract

Introduction: The role of nutraceuticals in the treatment of male infertility, especially in the “idiopathic form”, remains the subject of significant debate. Many antioxidants improve sperm motility but the exact mechanism by which they act is still unclear. Although several studies have shown a correlation between sperm motility and mitochondrial function, the effects of antioxidant therapy on mitochondrial membrane potential (MMP) are poorly studied. The first aim of this review was to evaluate the efficacy of antioxidants on mitochondrial function and, consequently, on sperm motility in male infertile patients. Material and Methods: we performed a systematic search of all randomized controlled and uncontrolled studies available in the literature that reported sperm motility and MMP at baseline and after antioxidant administration in-vivo and in-vitro in patients with idiopathic asthenozoospermia. Pubmed, MEDLINE, Cochrane, Academic One Files, Google Scholar and Scopus databases were used. Results: Unexpectedly, among 353 articles retrieved, only one study met our inclusion criteria and showed a significant effect of myoinositol on both MMP and sperm motility. We then summarized the main knowledge on anatomy and metabolism of sperm mitochondria, techniques allowing to assess sperm mitochondria function and its relationships with low sperm motility. Finally, we paid special attention to the effect of antioxidant/prokinetic molecules for the treatment of asthenozoospermia. Conclusions: This is the first systematic review that has attempted to evaluate the effects of antioxidants on MMP and sperm motility. Although results are not conclusive due to the dearth of studies, the close relationship between mitochondria and sperm motility is clear. The investigation of this correlation could provide valuable information to be exploited in clinical practice for the treatment of male infertility.

Quercetin and Naringenin Provide Functional and Antioxidant Protection to Stored Boar Semen

“…The MTT assessment revealed that in vitro exposure of spermatozoa to both flavonoids leads to a significant protection of the mitochondrial function, mirroring the preservation of sperm motility. The logical explanation for such observation would be that axonemes and dense fibers located the central part of spermatozoa are covered by mitochondria, responsible for the production of ATP, directly involved in the sperm motion [ 33 ]. Phenolic compounds have been recognized to exhibit protective effects on the mitochondrial structure and function, with QUE itself being revealed as a strong mitochondrial protector on numerous occasions.…”

“…Phenolic compounds have been recognized to exhibit protective effects on the mitochondrial structure and function, with QUE itself being revealed as a strong mitochondrial protector on numerous occasions. The most prominent oxidative stress-preventing characteristic of QUE is tied to its ability to directly inhibit ROS formation by enzymatic or non-enzymatic systems, particularly NADPH oxidase and NADH-dependent oxidoreductase, localized directly in the sperm mitochondria [ 33 , 34 ]. On the other hand, arguable dose-dependent effects of QUE towards the sperm mitochondria were observed by Silva et al [ 15 ].…”

Reduced spermatozoa functionality during stress is the consequence of adrenergic-mediated disturbance of mitochondrial dynamics markers

“…Epidemiological studies strongly suggested that stress-induced DNA damage may promote various diseases and that a stress-response-β2-adrenergic-receptors(β2-ADRs)-pathway regulates DNA damage 20 . ADRs can activate the biogenesis of new mitochondria, the key components of the stress response 6,8,9 , but also for sperm functionality 21 . Mitochondria are primarily responsible for meeting the enormous energy demands of the "fight and flight response" by using the large amounts of substrates that are made available by stress hormone-induced mobilization from energy storages 6,8,9 .…”

Ultrastructural Sperm Flagellum Defects in a Patient With CCDC39 Compound Heterozygous Mutations and Primary Ciliary Dyskinesia/Situs Viscerum Inversus

“…However, in none of these patients data of the genetic testing are available. Evidence supports the importance of sperm mitochondrial integrity for a normal sperm motility (Barbagallo et al, 2020). Mitochondria is an organelle confined in the mid piece of spermatozoa devoted to oxidative phosphorylation.…”

“…Mitochondria is an organelle confined in the mid piece of spermatozoa devoted to oxidative phosphorylation. There is agreement in literature on the role of sperm mitochondria to supply energy for sperm motility (Barbagallo et al, 2020). Sperm MMP is a bio-functional parameter indicating mitochondrial function.…”