Efficacy of Antioxidant Supplementation on Conventional and Advanced Sperm Function Tests in Patients with Idiopathic Male Infertility

Acetate attenuates lead-induced dysregulation of testicular steroidogenesis and spermatogenesis by targeting oxidative stress, inflammatory cytokines, and apoptosis

Lead exposure has been implicated in the aetiopathogenesis of male infertility via an oxidative stress-sensitive pathway. Conversely, acetate has been shown to confer cellular protection by improving the antioxidant defense mechanism. Yet, the effect of acetate on lead-induced testicular toxicity, viz., dysregulation of testicular steroidogenesis and spermatogenesis, has not been reported. The present study probed the influence of acetate on lead-induced dysregulation of testicular steroidogenesis and spermatogenesis. In our study, a reduction in body weight gain and testicular weight was identified in lead-exposed rats. While histopathological results established distortion of testicular histoarchitecture, reduced germ cell count, and suppressed spermatogenesis, biochemical studies confirmed that lead-deregulated testicular steroidogenesis was associated with reduced circulating gonadotropin-releasing hormone and gonadotropins, as well as down-regulated testicular 3β-HSD and 17β-HSD activities. These findings were accompanied by increased testicular malondialdehyde, TNF-α, IL-1β, and IL-6, and reduced glutathione, thiol and non-thiol protein levels, total antioxidant capacity, superoxide dismutase, and catalase activities. In addition, lead exposure increased NFkB and Bax levels, as well as caspase 3 activity, but reduced Bcl-2 levels. However, co-administration of acetate ameliorated lead-induced alterations. Collectively, acetate attenuated lead-induced dysregulation of testicular steroidogenesis and spermatogenesis by targeting oxidative stress, NFkB-mediated inflammation, and caspase 3-driven apoptosis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43188-024-00250-3.

Sperm chromatin: Evaluation, epigenetic signatures and relevance for embryo development and assisted reproductive technology outcomes

Sperm chromatin is distinct from somatic cell chromatin, as a result of extensive remodeling during the final stages of spermatogenesis. In this process, the majority of histones is replaced with protamines. The chromatin is consequently highly condensed and inert, which facilitates protection of the DNA. The sperm epigenomic landscape is shaped by histone retention, histone and protamine modification, DNA methylation, and RNAs. In recent years, sperm chromatin integrity and its epigenetic marks have been increasingly studied, and the constitution of sperm chromatin is steadily being uncovered. This growing body of research prompts assessment of the frequently overlooked involvement of sperm in fertility and embryonic development. Moreover, numerous endogenous and exogenous factors are known to affect sperm chromatin, which may in turn impact the reproductive success. Concerns have been raised about the effects of assisted reproductive technology (ART) on the sperm epigenome, embryonic development and offspring health. This review examines the structure and epigenetic signatures of sperm chromatin in the context of fertility and early embryonic development. Additionally, sperm chromatin evaluation and causes of aberrant integrity are outlined. Building on the knowledge discussed in the current review, future research should aim to elucidate the intricate relationship between all aspects of sperm chromatin and embryo development. This could lead to the uncovering of new targets for treating infertility, as well as the acquisition of much needed insights into the possible reciprocal association between ART and sperm chromatin integrity.

Impacts of Acrylamide on testis and spermatozoa

Acrylamide (ACR) is an industrial chemical used to produce polyacrylamide, a synthetic polymer with a wide range of applications. Depending on the dosage, its presence in occupational and environmental sources poses potential health risks to humans and animals. ACR can be formed in starchy foods cooked at high temperatures. Its effects on human sperm are not well understood. Animal studies indicate that ACR induces toxicity in the male reproductive system through oxidative stress mechanisms. Exposure to ACR alters the normal structure of testicular tubules, leading to congestion, interstitial edema, degeneration of spermatogenic cells, formation of abnormal spermatid giant cells, and necrosis and apoptosis. It also disrupts the balance of important biomarkers such as malondialdehyde, nitric oxide, superoxide dismutase, catalase, and glutathione. ACR has a negative impact on mitochondrial function, antioxidant enzymes, ATP production, and sperm membrane integrity, resulting in decreased sperm quality. Furthermore, it interferes with the expression of steroidogenic genes associated with testosterone biosynthesis. This review explores the detrimental effects of ACR on sperm and testicular function and discusses the potential role of antioxidants in mitigating the adverse effects of ACR on male reproduction.

Bibliometric and visual analysis on oxidative stress in gynecological and reproductive diseases: A systematic review

BACKGROUND

The imbalance between the generation and elimination of reactive oxygen species (ROS) is defined as oxidative stress (OS). Elevated levels of OS are implicated in various diseases, especially in gynecological and reproductive disorders. The abundance of recent literature makes it challenging to assimilate all available information. This bibliometric analysis seeks to depict the research landscape of OS in gynecological and reproductive diseases and to identify future hotspots and trends.

METHODS

The Web of Science Core Collection served as the source for articles related to OS in gynecological and reproductive diseases. CtieSpace and VOSviewer software were utilized to analyzed countries/regions, institutions, journals, authors, and keywords of all eligible articles.

RESULTS

A total of 1423 articles were included. There was a gradual increase in the number of publications in this field. The USA maintained the highest number of publications, with 372 articles. Cleveland Clinic was the leading institution in terms of publication volume, contributing 67 articles. In total, 6925 authors were identified. Agarwal A as the most frequently co-cited author, received 812 citations across 43 publications. The predominant clusters included "placenta," "polycystic ovary syndrome," "male infertility," and "oocyte quality." Notably, "oocyte quality'" was identified as a current key research topic.

CONCLUSION

There was an uptrend in the number of articles addressing OS in gynecological and reproductive diseases. However, international collaboration and exchange were limited. The topic of male infertility had remained a consistent area of interest, and research on oocyte quality is poised to become a potential focal point in the future.

A multi-modal approach to investigate Desmodium gangeticum's influence on stress-induced male infertility: In vivo, in vitro, and in silico assessments

Physical and psychological stress has an inverse relation with male libido and sperm quality. The present study investigates the potential fertility-enhancing properties of Desmodium gangeticum (DG) root extracts in male Wister rats subjected to immobilization-induced stress (SIMB). DG roots were extracted using n-hexane (HEDG), chloroform (CEDG), and water (AEDG). In the pilot study, aphrodisiac protentional was investigated at two doses (125 and 250 mg kg-1) of each extract. In the main study, the HEDG and AEDG at 125 and 250 mg kg-1 were challenged for the stress by immobilization (SIMB), for 6 h daily over 28 days. Parameters assessed included aphrodisiac effects, gonadosomatic index (GSI), semen quality, sperm quantity, fructose content, serum hormonal levels, testicular oxidative stress, and testicular histopathology. Additional in silico studies, including the lipid solubility index, molecular docking, molecular dynamics, and SymMap studies were conducted for validation. HEDG demonstrated significant aphrodisiac activity, improved - GSI, sperm quality and quantity, and fructose content, serum testosterone levels, histological changes induced by SIMB in the testes. Swiss ADME studies indicated Gangetin (a pterocarpan) had a high brain permeation index (4.81), a superior docking score (-8.22), and higher glide energy (-42.60), compared with tadalafil (-7.17). The 'Lig fit Prot' plot in molecular dynamics simulations revealed a strong alignment between Gangetin and phosphodiesterase type 5 (PDE5). HEDG exerts aphrodisiac effects by increasing blood testosterone levels and affecting PDE5 activity. The protective effects on spermatozoa-related parameters and testicular histological changes are attributed to the antioxidant and anti-inflammatory properties, of pterocarpan (gangetin).

Correlation between seminal plasma biochemical markers and semen parameters in idiopathic oligoasthenoteratospermia: identification of biomarkers for L-carnitine therapy

Background

L-carnitine therapy for idiopathic sperm abnormalities exhibits variable effectiveness, and currently, there are no established criteria to predict patient response. This study investigated correlations between seminal plasma markers and semen parameters to identify biomarkers that can guide indications for L-carnitine therapy indications in patients with idiopathic sperm abnormalities.

Methods

A retrospective review was conducted on 223 male patients with idiopathic oligoasthenoteratospermia, who sought medical attention at our clinic between January 2020 and October 2022. These patients underwent a pretreatment seminal plasma biochemical analysis, followed by a three-month continuous L-carnitine treatment. The correlation between seminal plasma biochemical parameters and pretreatment semen parameters was analyzed. Semen quality was compared between cases with normal and abnormal seminal plasma biochemical parameters, both pretreatment and posttreatment. The correlation between the changes in semen parameters after treatment and seminal plasma biochemical parameters were investigated.

Results

Correlation analyses revealed significant associations between all pretreatment semen parameters and seminal plasma biochemical markers, except for liquefying time and the ratio of normal morphology. Subgroup analysis, stratified by seminal fructose, zinc, citric acid, and neutral glycosidase levels, demonstrated that abnormal groups exhibited significantly different levels of semen parameters compared with the normal groups. The changing difference and changing ratio in the ratio of forward motile sperm showed a negative correlation with seminal fructose levels (r=-0.165 and -0.144). The changing difference in semen volume was negatively correlated with the level of seminal neutral glycosidase (r=-0.158). The changing ratio in semen volume, sperm concentration, total sperm count, and count of forward motile sperm all exhibited negative correlations with the levels of seminal neutral glycosidase (range from -0.178 to -0.224).

Conclusion

Seminal plasma biochemical markers, particularly fructose and neutral glycosidase, may serve as valuable indicators for determining the eligibility of patients with idiopathic sperm abnormalities for L-carnitine therapy.

Decentralized ORP Measurements for Gut Redox Status Monitoring: Toward Personalized Gut Microbiota Balance

Gut microbiome targeting has emerged as a new generation of personalized medicine and a potential wellness and disease driver. Specifically, the gut redox balance plays a key role in shaping the gut microbiota and its link with the host, immune system, and disease evolution. In this sense, precise and personalized nutrition has proven synergy and capability to modulate the gut microbiome environment through the formulation of dietary interventions, such as vitamin support. Accordingly, there are urgent demands for simple and effective analytical platforms for understanding the relationship between the tailored vitamin administration and the gut microbiota balance by rapid noninvasive on-the-spot oxidation/reduction potential monitoring for frequent and close surveillance of the gut redox status and targeting by personalized nutrition interventions. Herein, we present a disposable potentiometric sensor chip and a homemade multiwell potentiometric array to address the interplay of vitamin levels with the oxidation/reduction potential in human feces and saliva. The potentiometric ORP sensing platforms have been successfully validated and scaled up for the setup of a multiapplication prototype for cross-talk-free simple screening of many specimens. The interpersonal variability of the gut microbiota environment illustrates the potential of feces and saliva samples for noninvasive, frequent, and decentralized monitoring of the gut redox status to support timely human microbiota surveillance and guide precise dietary intervention toward restoring and promoting personalized gut redox balance.

Oxidative stress affects sperm health and fertility-Time to apply facts learned at the bench to help the patient: Lessons for busy clinicians

Background

Increased oxidative stress (OS), resulting from the delicate balance between reactive oxygen species (ROS) production and antioxidant defense, is closely linked to sperm abnormalities and male subfertility. Elevated ROS levels particularly affect sperm quality. The vulnerability of spermatozoa to ROS is due to the absence of DNA repair mechanisms and the high presence of polyunsaturated fatty acids in their membranes.

Methods

This article updates and advances our understanding of the molecular damage caused by OS in spermatozoa, including lipid peroxidation, DNA damage, motility, and functionality. Additionally, the review discusses the challenges in diagnosing OS in semen and recommends accurate and sensitive testing methods. Case studies are utilized to demonstrate the effective management of male infertility caused by OS.

Main findings

Highlighting the need to bridge the gap between research and clinical practice, this review suggests strategies for clinicians, such as lifestyle and dietary changes and antioxidant therapies. The review emphasizes lifestyle modifications and personalized care as effective strategies in managing male infertility caused by OS.

Conclusion

This review calls for early detection and intervention and interdisciplinary collaboration to improve patient care in male infertility cases related to increased OS.

Effect of obstructive sleep apnea on semen quality

BACKGROUND

Obstructive sleep apnea (OSA) has several notable complications such as hypertension and diabetes. Studies have also shown that OSA is associated with erectile dysfunction and reduced androgen levels. However, the effect of OSA on semen quality remains poorly studied.

METHODS

Men attending a tertiary reproductive center for semen analysis were tested with a portable sleep breathing monitor. Patients were divided into four groups based on their apnea hypopnea index: none, mild, moderate, and severe obstructive sleep apnea. Differences between groups were assessed using χ2, and associations were tested with multiple regression analysis.

RESULTS

We included a total of 175 male subjects with a mean age of 32.2 ± 3.6 years. There were significant differences between groups in progressive sperm motility (%) (43 ± 16, 42 ± 17, 36 ± 18, 29 ± 18, respectively; p = 0.002), total motility (%) (59 ± 19, 59 ± 20, 49 ± 21, 42 ± 20, respectively; p = 0.010), and vitality (%) (80 ± 10, 81 ± 11, 79 ± 8, 72 ± 19, respectively; p = 0.039). Asthenospermia (progressive motility < 35%) was significantly more common in subjects with OSA (χ2 = 5.195, p = 0.023). In multiple regression models, after adjusting for age and body mass index, apnea hypopnea index remained negatively and significantly associated with progressive motility, total motility, and vitality.

CONCLUSIONS

OSA is an independent risk factor for sperm motility and vitality, and further investigation is now needed to determine if continuous positive pressure ventilation or other therapies can improve semen quality in these patients.

Oxidative Stress and Male Infertility: The Protective Role of Antioxidants

Oxidative stress is a significant factor in male infertility, compromising sperm function and overall reproductive health. As male infertility garners increasing attention, effective therapeutic interventions become paramount. This review investigates the therapeutic role of antioxidants in addressing male infertility. A detailed examination was conducted on antioxidants such as vitamin C, E, B12, D, coenzyme Q10, zinc, folic acid, selenium, l-carnitine, l-arginine, inositols, and alpha-lipoic acid. This analysis examines the methodologies, outcomes, and constraints of current clinical studies. Antioxidants show notable potential in counteracting the negative effects of oxidative stress on sperm. Based on the evidence, these antioxidants, individually or synergistically, can enhance sperm health and reproductive outcomes. However, certain limitations in the studies call for careful interpretation. Antioxidants are integral in tackling male infertility attributed to oxidative stress. The current findings underscore their therapeutic value, yet there's a pressing need for deeper, comprehensive research. Future studies should focus on refining dosage guidelines, identifying potential side effects, and discerning the most efficacious antioxidant combinations for male infertility solutions.

New Insights on Sperm Function in Male Infertility of Unknown Origin: A Multimodal Approach

The global trend of rising (male) infertility is concerning, and the unidentifiable causes in half of the cases, the so-called unknown origin male infertility (UOMI), demands a better understanding and assessment of both external/internal factors and mechanisms potentially involved. In this work, it was our aim to obtain new insight on UOMI, specifically on idiopathic (ID) and Unexplained male infertility (UMI), relying on a detailed evaluation of the male gamete, including functional, metabolic and proteomic aspects. For this purpose, 1114 semen samples, from males in couples seeking infertility treatment, were collected at the Reproductive Medicine Unit from the Centro Hospitalar e Universitário de Coimbra (CHUC), from July 2018-July 2022. Based on the couples' clinical data, seminal/hormonal analysis, and strict eligibility criteria, samples were categorized in 3 groups, control (CTRL), ID and UMI. Lifestyle factors and anxiety/depression symptoms were assessed via survey. Sperm samples were evaluated functionally, mitochondrially and using proteomics. The results of Assisted Reproduction Techniques were assessed whenever available. According to our results, ID patients presented the worst sperm functional profile, while UMI patients were similar to controls. The proteomic analysis revealed 145 differentially expressed proteins, 8 of which were specifically altered in ID and UMI samples. Acrosin (ACRO) and sperm acrosome membrane-associated protein 4 (SACA4) were downregulated in ID patients while laminin subunit beta-2 (LAMB2), mannose 6-phosphate isomerase (MPI), ATP-dependent 6-phosphofructokinase liver type (PFKAL), STAR domain-containing protein 10 (STA10), serotransferrin (TRFE) and exportin-2 (XPO2) were downregulated in UMI patients. Using random forest analysis, SACA4 and LAMB2 were identified as the sperm proteins with a higher chance of distinguishing ID and UMI patients, and their function and expression variation were in accordance with the functional results. No alterations were observed in terms of lifestyle and psychological factors among the 3 groups. These findings obtained in an experimental setting based on 3 well-defined groups of subjects, might help to validate new biomarkers for unknown origin male infertility (ID and UMI) that, in the future, can be used to improve diagnostics and treatments.

Micronutrient supplements as antioxidants in improving sperm quality and reducing DNA fragmentation

BACKGROUND

Spermatogenesis and sperm quality may be negatively impacted by an increase in reactive oxygen species. This study investigates the efficacy of combined antioxidant therapy for treating male infertility, as measured by semen analyses and the sperm DNA fragmentation index (DFI). Infertile men with a high sperm DNA fragmentation index were instructed to take two oral micronutrient capsules daily for three months. Each antioxidant formulation contained 60 mg vitamin E, 400 µg folic acid, 30 mg selenium, 125 mg L-arginine, 220 mg L-carnitine, 7.5 mg coenzyme Q10, 40 mg L-glutathione, and 20 mg zinc citrate. At entry and post-treatment, the general characteristics, semen analysis, and sperm chromatin dispersion assays were recorded and compared.

RESULTS

After three months of treatment with antioxidant compounds, the quality of spermatozoa improved significantly, as indicated by a decrease in the mean DNA fragmentation index from 45.6 ± 17.2% to 34.8 ± 20.3%; an increase in sperm concentration from 29.7 × 106/mL to 35.7 × 106/mL (p < 0.001), an increase in a total number of spermatozoa from 72.1 × 106 to 95.5 × 106 (p = 0.012), and an increase in the vitality from 75.5 ± 17.1 to 81.1 ± 14.4% viable forms (p < 0.001).

CONCLUSIONS

Micronutrient supplementation can improve sperm quality and DNA integrity in infertile men. Men with infertility and significant sperm DNA fragmentation who take antioxidants for three months experience a reduction in DNA fragmentation index and an increase in sperm quality as measured by the semen analysis.

TRIAL REGISTRATION

NCT04509583 . Registered 12 August 2020, Hue University of Medicine and Pharmacy Ethics Committee-Retrospectively registered.

The Palliative and Antioxidant Effects of Hesperidin against Lead-Acetate-Induced Testicular Injury in Male Wistar Rats

Lead (Pb)-induced reprotoxicity is a detrimental consequence of Pb exposure, which results in abnormal spermatogenesis, testicular degeneration, and pathogenic sperm changes. The association between impaired male reproductive function and Pb-induced oxidative stress (OS) has been demonstrated, with consequent testicular antioxidant deficiency. The current study investigated the protective role of the natural antioxidant hesperidin (HSD) against lead-acetate (PbAc)-induced testicular toxicity. Male Wistar rats (n = 40) were randomly divided into four experimental groups: Group I (negative control) received 2.0 mL/kg BW 0.9% saline; Group II received 100 mg/kg BW PbAc; Group III received 100 mg/kg BW HSD; and Group IV received HSD two hours before PbAc using the abovementioned doses. The treatments were administered daily for 30 consecutive days. The results showed that HSD treatment significantly restored PbAc-induced decrease in body, epididymal, and testicular weights as well as in semen parameters, reproductive hormones, and testicular markers of OS. Reduced MDA levels and improved testicular histopathological findings were also observed. Collectively, this study sheds light on the preventive role of HSD against PbAc-induced testicular injury, which is mediated via the suppression of OS and the modulation of reproductive hormones as well as the plausibility of HSD being used as a supplementary therapeutic option for recovery.

Role of oxidative stress in male infertility

Abstract

Infertility affects millions of couples worldwide. Oxidative stress (OS) causes peroxidation of lipids and damage to spermatozoa, thus, reducing the quality of seminal parameters. In addition, the differences in the levels of antioxidants and reactive oxygen species (ROS) caused by intrinsic and extrinsic variables linked to lifestyle, diet, genetics, and OS also contribute to male infertility. High levels of ROS result in sperm damage of sperm parameters due to lipid peroxidation and oxidation of proteins. Other significant causes of ROS include changes in sex hormone levels, sperm DNA damage, including mutations, and immature spermatozoa. Treating the root causes of OS, by changing one's lifestyle, as well as antioxidant therapy, may be helpful strategies to fight OS-related infertility. However, the determination of male infertility induced by OS is currently a challenge in the field of reproductive health research. This review intends to describe the role of oxidative stress on male infertility and the current understanding of its management.

Lay summary

The inability to conceive affects many couples globally. Oxidative stress refers to imbalances between different oxygen species which can lead to male fertility problems by damaging sperm and semen. Oxidative stress may be caused by several factors, including diets high in fats, sugars and processed foods, lifestyle (including smoking, alcohol consumption and having a sedentary lifestyle), and genetics. Treatment that focuses on the root cause may help combat male infertility. However, there is currently no consensus on the best way to treat male fertility problems, particularly those associated with oxidative stress. This paper describes the role of oxidative stress on male infertility and discusses the current techniques employed in treating male fertility issues.

The effect of co-administration of artemisinin and N-acetyl cysteine on antioxidant status, spermatological parameters and histopathology of testis in adult male mice

OBJECTIVES

This in vivo study aimed to evaluate the effect of various concentrations of artemisinin (Art) alone or together with N-acetyl cysteine (NAC) on spermatological indices, antioxidant status, and histopathological parameters of testicular tissue in adult male mice.

METHODS

Six groups of five healthy male mice (25-30 g) were randomly assigned to different experimental groups. These groups received DMSO and corn oil (0.1%) as an Art solvent (Control), 50 mg kg^-1 Art (Art-50), 250 mg kg^-1 Art (Art-250), 50 mg kg^-1 Art + 150 mg kg^-1 NAC (Art-50+NAC-150), 250 mg kg^-1 Art + 150 mg kg^-1 NAC (Art-250+NAC-150) and 150 mg kg^-1 NAC (NAC-150) for a period of 7 days. Testes and epididymis were prepared to evaluate the malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), spermatological indices, and histological parameters.

RESULTS

We showed that the high dose of Art (Art-250) significantly reduced the sperm count, motility, viability, and the activity of CAT and increased the levels of MDA compared to the control group. Also, the overdose of Art caused adverse changes in testicular tissue. Co-administration of NAC with Art (Art-250+NAC-150) corrected the adverse effects of Art.

CONCLUSIONS

The current study reports that a high dose of Art affects, spermatological parameters, antioxidant/stress oxidative status of the male reproductive system, and NAC is capable neutralize all adverse effects caused by Art.

Machine Learning Predictive Models for Evaluating Risk Factors Affecting Sperm Count: Predictions Based on Health Screening Indicators

In many countries, especially developed nations, the fertility rate and birth rate have continually declined. Taiwan's fertility rate has paralleled this trend and reached its nadir in 2022. Therefore, the government uses many strategies to encourage more married couples to have children. However, couples marrying at an older age may have declining physical status, as well as hypertension and other metabolic syndrome symptoms, in addition to possibly being overweight, which have been the focus of the studies for their influences on male and female gamete quality. Many previous studies based on infertile people are not truly representative of the general population. This study proposed a framework using five machine learning (ML) predictive algorithms-random forest, stochastic gradient boosting, least absolute shrinkage and selection operator regression, ridge regression, and extreme gradient boosting-to identify the major risk factors affecting male sperm count based on a major health screening database in Taiwan. Unlike traditional multiple linear regression, ML algorithms do not need statistical assumptions and can capture non-linear relationships or complex interactions between dependent and independent variables to generate promising performance. We analyzed annual health screening data of 1375 males from 2010 to 2017, including data on health screening indicators, sourced from the MJ Group, a major health screening center in Taiwan. The symmetric mean absolute percentage error, relative absolute error, root relative squared error, and root mean squared error were used as performance evaluation metrics. Our results show that sleep time (ST), alpha-fetoprotein (AFP), body fat (BF), systolic blood pressure (SBP), and blood urea nitrogen (BUN) are the top five risk factors associated with sperm count. ST is a known risk factor influencing reproductive hormone balance, which can affect spermatogenesis and final sperm count. BF and SBP are risk factors associated with metabolic syndrome, another known risk factor of altered male reproductive hormone systems. However, AFP has not been the focus of previous studies on male fertility or semen quality. BUN, the index for kidney function, is also identified as a risk factor by our established ML model. Our results support previous findings that metabolic syndrome has negative impacts on sperm count and semen quality. Sleep duration also has an impact on sperm generation in the testes. AFP and BUN are two novel risk factors linked to sperm counts. These findings could help healthcare personnel and law makers create strategies for creating environments to increase the country's fertility rate. This study should also be of value to follow-up research.

The effect of alpha-lipoic acid on sperm functions in rodent models for male infertility: A systematic review

In this systematic review, we assessed different studies to evaluate the protective effect of alpha-lipoic acid (ALA), as a multifaceted antioxidant, on sperm functions in rodent models. Four databases were searched to find papers reporting the effect of ALA treatment on animal models of male infertility. Up to December 2022, 11,787 articles were identified to explain the ALA protective effects. The included studies were evaluated for eligibility and risk of bias (CRD42022341370). Finally, we identified 23 studies that explain the effect of ALA on sperm functions in rodents. Among them, 15 studies indicated that ALA could restore sperm parameters. Six studies showed a significant reduction in sperm DNA damage by ALA treatment. Seventeen papers displayed the ALA antioxidant ability, and four studies indicated the ALA anti-inflammatory effect. Besides, thirteen studies displayed that ALA could modulate androgenesis. Also, eighteen studies revealed that ALA restored the testicular architecture to normal, and was also effective in restoring reproductive performance in two included studies. This systematic review provided cogent evidence for the protective effect of ALA in rodent models for male infertility by re-establishing spermatogenesis and steroidogenesis and maintaining redox and immune systems homeostasis.

Coenzyme Q10 and Melatonin for the Treatment of Male Infertility: A Narrative Review

BACKGROUND

Lifestyle and environmental factors can negatively impact fertility by means of oxidative stress. In this context, antioxidant supplementation therapy has gained much interest in recent years, and different molecules, alone or in combination, have been studied.

OBJECTIVE

The purpose of the present review is to investigate the evidence regarding the efficacy of coenzyme Q10 (CoQ10) and melatonin on male infertility.

METHODS

A literature search using PUBMED database from 2000 to October 2022 was performed to explore the role of CoQ10 and melatonin on male reproductive function.

CONCLUSIONS

The analysis involved a narrative synthesis. CoQ10, alone or in combination, appears to reduce testicular oxidative stress and sperm DNA fragmentation and to improve sperm parameters; particularly sperm motility. Moreover, CoQ10 treatment is associated with higher pregnancy rates, both naturally and through assisted reproductive technology (ART). Larger studies are needed to precisely determine its clinical efficacy. Melatonin is a known antioxidant and preclinical studies have shown its ability to modulate reproductive function through hormonal and immune system regulation and sperm cell proliferation. Regardless, clinical studies are necessary to assess its potential in male infertility.

Alpha-Lipoic Acid Ameliorates Sperm DNA Damage and Chromatin Integrity in Men with High DNA Damage: A Triple Blind Randomized Clinical Trial

OBJECTIVE

Evidence suggests the contributory role of oxidative stress (OS) to sperm DNA damage and eventually, male infertility. Antioxidant supplementation has exhibited favorable results regarding seminal OS, sperm DNA damage, and chromatin integrity. We aimed to evaluate the effect of alpha-lipoic acid (ALA) supplementation on semen analysis, sperm DNA damage, chromatin integrity, and seminal/intracellular OS in infertile men with high sperm DNA damage.

MATERIALS AND METHODS

In this randomized triple-blind placebo-controlled clinical trial study, we opted for a triple-blind controlled clinical trial design. Considering the study's inclusion criteria for the level of sperm DNA fragmentation (higher than the threshold of 30 and 15%), 70% of participants were selected for this clinical research study. Subjects were divided into case and control groups receiving oral ALA (600 mg/day) and placebo for eighty days, respectively. Sperm parameters and functional tests were examined and compared before and after treatment. The final sample size was 34 and 29 for ALA and placebo receivers, respectively.

RESULTS

No significant differences were observed about anthropometrics and baseline measures of semen analysis, DNA damage, OS, and chromatin integrity between the two groups. Conventional semen parameters were enhanced insignificantly in both groups (P>0.05). DNA damage decreased significantly in the ALA group, as per sperm chromatin structure assay (SCSA, P<0.001). Moreover, chromomycin A3 (CMA3) staining results indicated a decrease in nuclear protamine deficiency post-ALA therapy (P=0.004). Lipid peroxidation decreased significantly after treatment with ALA (P=0.003). Further, seminal antioxidant capacity/activity did not differ significantly in either of the groups (registration number: IRCT20190406043177N1).

CONCLUSION

An 80-day course of oral ALA supplementation (600 mg/day) alleviates sperm OS, DNA damage, and chromatin integrity in men with high sperm DNA damage.

Molecular Clues to Understanding Causes of Human-Assisted Reproduction Treatment Failures and Possible Treatment Options

More than forty years after the first birth following in vitro fertilization (IVF), the success rates of IVF and of IVF-derived assisted reproduction techniques (ART) still remain relatively low. Interindividual differences between infertile couples and the nature of the problems underlying their infertility appear to be underestimated nowadays. Consequently, the molecular basis of each couple's reproductive function and of its disturbances is needed to offer an individualized diagnostic and therapeutic approaches to each couple, instead of applying a standard or minimally adapted protocols to everybody. Interindividual differences include sperm and oocyte function and health status, early (preimplantation) embryonic development, the optimal window of uterine receptivity for the implanting embryo, the function of the corpus luteum as the main source of progesterone production during the first days of pregnancy, the timing of the subsequent luteoplacental shift in progesterone production, and aberrant reactions of the uterine immune cells to the implanting and recently implanted embryos. In this article, the molecular basis that underlies each of these abnormalities is reviewed and discussed, with the aim to design specific treatment options to be used for each of them.

Sperm Morphology Assessment in the Era of Intracytoplasmic Sperm Injection: Reliable Results Require Focus on Standardization, Quality Control, and Training

Semen analysis is the first, and frequently, the only step in the evaluation of male fertility. Although the laboratory procedures are conducted according to the World Health Organization (WHO) guidelines, semen analysis and especially sperm morphology assessment is very difficult to standardize and obtain reproducible results. This is mainly due to the highly subjective nature of their evaluation. ICSI is the choice of treatment when sperm morphology is severely abnormal (teratozoospermic). Hence, the standardization of laboratory protocols for sperm morphology evaluation represents a fundamental step to ensure reliable, accurate and consistent laboratory results that avoid misdiagnoses and inadequate treatment of the infertile patient. This article aims to promote standardized laboratory procedures for an accurate evaluation of sperm morphology, including the establishment of quality control and quality assurance policies. Additionally, the clinical importance of sperm morphology results in assisted reproductive outcomes is discussed, along with the clinical management of teratozoospermic patients.

[Hyperoside protects mouse spermatocytes GC-2 cells from oxidative damage by activating the Keap1/Nrf2/HO-1 pathway]

OBJECTIVE

To study the protective effect of hyperoside (Hyp) against ydrogen peroxide (H2O2)- induced oxidative damage in mouse spermatocytes GC-2 cells and explore the role of the Keap1/Nrf2/HO-1 pathway in this protective mechanism.

METHODS

GC-2 cells were treated with 2.5 mmol/L azaacetylcysteine (NAC), 50, 100, and 200 μmol/L hyperoside, or the culture medium for 48 h before exposure to H2O2 (150 μmol/L) for 2 h. CCK-8 assay was used to detect the changes in cell viability, and cell apoptosis was analyzed using flow cytometry. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), catalase (CAT) activity and malondialdehyde (MDA) in the culture medium. Western blotting and RT-qPCR were used to detect the protein and mRNA expression levels of nuclear factor erythroid 2-related factor2 (Nrf2), Kelch-like ECH-associated protein 1 (Keap1), and heme oxygenase-1 (HO-1); the nuclear translocation of Nrf2 was detected using immunofluorescence assay.

RESULTS

Exposure to H2O2 significantly lowered the proliferation rate, reduced the activities of SOD, GSH and CAT, and obviously increased MDA content, cell apoptosis rate, and the expressions of Keap1 and Nrf2 mRNA and Keap1 protein in GC-2 cells (P < 0.05 or 0.01). Treatment of the cells prior to H2O2 exposure with either NAC or 200 μmol/L hyperoside significantly increased the cell proliferation rate, enhanced the activities of SOD, GSH-PX and CAT, and lowered MDA content and cell apoptosis rate (P < 0.05). Treatment with 200 μmol/L hyperoside significantly decreased the mRNA and protein expressions of Keap1 and increased the expressions of HO-1 mRNA and the protein expressions of Nrf2 and HO-1 (P < 0.05 or 0.01). Hyperoside also caused obvious nuclear translocation of Nrf2 in the cells (P < 0.05).

CONCLUSION

Hyperoside protects GC-2 cells against H2O2- induced oxidative damage possibly by activation of the Keap1/Nrf2/HO-1 signaling pathway.

Comparison of the effects of coenzyme Q10 and Centrum multivitamins on semen parameters, oxidative stress markers, and sperm DNA fragmentation in infertile men with idiopathic oligoasthenospermia

Objective

Oxidative stress and sperm DNA fragmentation (SDF) have been linked to idiopathic male infertility (IMI). Various antioxidants have been tried to improve semen parameters and fertility potential in IMI patients, but with inconsistent results. The study aimed to compare the effects of coenzyme Q10 (CoQ10) and Centrum multivitamins on semen parameters, seminal antioxidant capacity, and SDF in infertile men with idiopathic oligoasthenospermia (OA).

Methods

This prospective controlled clinical study involved 130 patients with idiopathic OA and 58 fertile controls. The patients were divided randomly into two groups: the first group received CoQ10 (200 mg/day orally) and the second group received Centrum multivitamins (1 tablet/day) for 3 months. Semen parameters, CoQ10 levels, reactive oxygen species (ROS), total antioxidant capacity (TAC), catalase, SDF, and serum hormone levels (follicle-stimulating hormone, luteinizing hormone, testosterone, and prolactin) were compared at baseline and after 3 months.

Results

Both CoQ10 and Centrum improved sperm concentration and motility, but the improvement was greater with Centrum therapy (p<0.05). Similarly, both therapies improved antioxidant capacity, but TAC and catalase improvement was greater (p<0.01 and p<0.001 respectively) with CoQ10, whereas ROS (p<0.01) and SDF (p<0.001) improvements were greater with Centrum administration. Centrum therapy was associated with reduced serum testosterone (p<0.05).

Conclusion

In conclusion, both CoQ10 and Centrum were effective in improving semen parameters, antioxidant capacity, and SDF, but the improvement was greater with Centrum than with CoQ10. Therefore, Centrum—as a source of combined antioxidants—may provide more effective results than individual antioxidants such as CoQ10 in the treatment of infertile men with idiopathic OA.

Natural self-emulsifying reversible hybrid-hydrogel delivery (N'SERH) of tocopherol enhances bioavailability and modulates alcohol-induced reproductive toxicity in rats

Alpha-tocopherol (α-Toc), an antioxidant vitamin, has been widely prescribing in the treatment of infertility, in spite of its limited oral bioavailability. The present study describes the enhanced bioavailability and efficacy of a novel 'natural self-emulsifying reversible hydrogel' (N'SERH)-based oral delivery form of α-Toc-rich sunflower oil (Tα-fen) using fenugreek galactomannan hydrogel scaffold (hybrid-FENUMATTM ). Tα-fen was characterised by FTIR, SEM, TEM and DLS as a hybrid-hydrogel powder. The bioavailability study on thirty (n = 30) male Sprague Dawley rats randomised into two groups indicated 4.84-fold increase in the oral bioavailability when the formulation was provided at 15 mg/kg b. wt. of α-Toc by oral gavage. The efficacy study on 24 animals randomised into four groups as control, ethanol treated (4 mg/kg b. wt.), ethanol+unformulated, UTα (15 mg/kg b. wt.) and ethanol+formulation, Tα-fen (15 mg/kg b. wt.) revealed significant improvement (*p < 0.05) and reversal of alcohol-induced reproductive toxicity as evident from the enhanced sperm count, motility and viability parameters, testosterone levels, fructose content, and SDH activity and plasma antioxidant status among Tα-fen-treated rats, compared with unformulated, UTα-treated group. Histopathology further confirmed the reversal of the alterations in the testes morphology of Tα-fen-treated animals, indicating its promising potential in the treatment of reproductive health issues.

Viral Infections and Male Infertility: A Comprehensive Review of the Role of Oxidative Stress

Viral infections have been a part of human existence to date, though viruses have posed a huge threat with various outbreaks lately. These threats are associated with reproductive health challenges, especially male infertility. The prime focus of this review is to highlight the mechanisms associated with viral infection-induced male infertility/subfertility and identify new treatment strategies with the aim to preserve male fertility. The reviewed data showed that viral infections stimulate inflammatory responses, resulting in the release of proinflammatory cytokines, which induces oxidative stress. This oxido-inflammatory cycle could continue in a vicious cycle and threaten male fertility. Existing data from human and experimental studies show that viral infection-induced oxido-inflammatory response results in testicular damage, atrophy of the seminiferous tubules and Sertoli cells, and reduced Leydig cell mass. This is accompanied by reduced circulatory testosterone, impaired spermatogenesis, reduced sperm motility, lipid peroxidation, DNA fragmentation and apoptosis of the sperm cells. Based on the available pieces of evidence, antioxidant therapy, in vivo and in vitro, may be beneficial and protects against the potential risk of male infertility from viral infection. It is, however recommended that more clinical studies be conducted to demonstrate the possible protective roles of antioxidants used as adjuvant therapy in viral infections, and in the in vitro treatment of semen samples for those utilizing semen washing and artificial reproductive techniques.

Predictors of pregnancy and time to pregnancy in infertile men with idiopathic oligoasthenospermia pre- and post-coenzyme Q10 therapy

Different antioxidants including coenzyme Q10 (CoQ10) have been tried to treat idiopathic male infertility (IMI) with variable results. Therefore, this study aimed to determine the clinical and biochemical predictors of pregnancy outcome and time to pregnancy (TTP) in infertile men with idiopathic oligoasthenospermia (OA) pre‐ and post‐CoQ10 therapy. This prospective controlled clinical study included 178 male patients with idiopathic OA and 84 fertile men (controls). Patients received 200 mg of oral CoQ10 once daily for 6 months. Demographics, semen parameters, seminal CoQ10 levels, reactive oxygen species (ROS) levels, total antioxidant capacity (TAC), catalase (CAT), glutathione peroxidase (GPx), sperm DNA fragmentation (SDF) and body mass index were measured and compared at baseline and after 6 months. All participants were followed up for another 18 months for pregnancy outcome and TTP. CoQ10 therapy for 6 months significantly improved semen parameters, antioxidant measures and reduced SDF. The pregnancy rate was 24.2% and TTP was 20.52 ± 6.72 months in patients as compared to 95.2% and 5.73 ± 6.65 months in fertile controls. After CoQ10 therapy, CoQ10 level, sperm concentration, motility and ROS were independent predictors of pregnancy outcome and CoQ10 level, male age, sperm concentration, motility, ROS and GPx were independent predictors of TTP in patients. In conclusion, CoQ10 therapy of 6 months is a potential treatment for men with idiopathic OA. CoQ10 level, male age, semen parameters, ROS and GPx could potentially be used as diagnostic biomarkers for male fertility and predictors for pregnancy outcome and TTP in these patients.

Oxidative Stress and Toxicity in Reproductive Biology and Medicine: A Comprehensive Update on Male Infertility Volume II - Conclusion

Infertility is a globally under-recognized public health problem significantly impacting individual health and socioeconomics affecting millions of couples. The reasons for infertility are manifold and not only include many couples decision to postpone having children but also diseases (e.g., diabetes, infections, or varicocele), lifestyle (e.g., obesity), and environmental factors (e.g., bisphenol A, DTT or dioxin). In the pathology of many causes of infertility, oxidative stress plays a significant role as reactive oxygen species (ROS) exert significant detrimental effects. On the other hand, a small amount of ROS is essential to trigger physiological events such as capacitation. Therefore, a fine balance between oxidation and reduction has to be maintained. Apart from treating the underlying disease or correcting the cause of the infertility, oxidative stress can be treated by antioxidant supplementation. Since plants and their extracts contain numerous phytochemicals which exhibit antioxidant activity, many people tend to use herbal products. Alternatively, isolated antioxidants such as vitamin C or E are also used. However, when using purified antioxidants, it is essential that the redox balance is maintained to avoid a "reductive stress" situation, which is as harmful as oxidative stress.

The Effect of Antioxidants on Sperm Quality Parameters and Pregnancy Rates for Idiopathic Male Infertility: A Network Meta-Analysis of Randomized Controlled Trials

PURPOSE

Male infertility is a global public health issue recognized by the WHO. Recently, antioxidants are increasingly used to treat idiopathic male infertility. However, the lack of available evidence has led to the inability to rank the effects of antioxidants on the sperm quality parameters and pregnancy rate of infertile men. This network meta-analysis studied the effects of different antioxidants on the sperm quality and pregnancy rate of idiopathic male infertility.

METHODS

We searched PubMed, Embase, Web of Science, and Cochrane Library databases for randomized controlled trials (RCTs). The weighted mean difference (WMD) and odds ratio (OR) were applied for the comparison of continuous and dichotomous variables, respectively, with 95% CIs. The outcomes were sperm motility, sperm concentration, sperm morphology, and pregnancy rate.

RESULTS

A total of 23 RCTs with 1,917 patients and 10 kids of antioxidants were included. l-Carnitine, l-carnitine+l-acetylcarnitine, coenzyme-Q10, ω-3 fatty acid, and selenium were more efficacious than placebo in sperm quality parameters. l-Carnitine was ranked first in sperm motility and sperm morphology (WMD 6.52% [95% CI: 2.55% to 10.05%], WMD 4.96% [0.20% to 9.73%]). ω-3 fatty acid was ranked first in sperm concentration (WMD 9.89 × 10⁶/ml, [95% CI: 7.01 to 12.77 × 10⁶/ml]). In terms of pregnancy rate, there was no significant effect as compared with placebo.

CONCLUSIONS

l-Carnitine was ranked first in sperm motility and sperm morphology. ω-3 fatty acid was ranked first in sperm concentration. Coenzyme-Q10 had better effective treatment on sperm motility and concentration. Furthermore, high-quality RCTs with adequate sample sizes should be conducted to compare the outcomes of different antioxidants.

Oxidative Stress-Induced Male Infertility: Role of Antioxidants in Cellular Defense Mechanisms

Male infertility is linked to several environmental and mutagenic factors. Most of these factors, i.e., lifestyle, radiations, and chemical contaminations, work on the fundamental principles of physics, chemistry, and biology. Principally, it may induce oxidative stress (OS) and produce free radicals within the cells. The negative effect of OS may enhance the reactive oxygen species (ROS) levels in male reproductive organs and impair basic functions in a couple's fertility. Evidence suggests that infertile men have significantly increased ROS levels and a reduced antioxidant capacity compared with fertile men. Although, basic spermatic function and fertilizing capacity depend on a delicate balance between physiological activity of ROS and antioxidants to protect from cellular oxidative injury in sperm, that is essential to achieve pregnancy. The ideal oxidation-reduction (REDOX) equilibrium requires a maintenance of a range of ROS concentrations and modulation of antioxidants. For this reason, the chapter focuses on the effects of ROS in sperm functions and the current concepts regarding the benefits of medical management in men with diminished fertility and amelioration of the effect to improve sperm function. Also, this evidence-based study suggests an increasing rate of infertility that poses a global challenge for human health, urging the need of health care professionals to offer a correct diagnosis, comprehension of the process, and an individualized management of the patients.

The combined effect of lifestyle intervention and antioxidant therapy on sperm DNA fragmentation and seminal oxidative stress in IVF patients: a pilot study

PURPOSE

Sperm DNA fragmentation (SDF) and seminal oxidative stress are emerging measurable factors in male factor infertility, which interventions could potentially reduce. We evaluated (i) the impact of lifestyle changes combined with oral antioxidant intake on sperm DNA fragmentation index (DFI) and static oxidation-reduction potential (sORP), and (ii) the correlation between DFI and sORP.

MATERIALS AND METHODS

We conducted a prospective study involving 93 infertile males with a history of failed IVF/ICSI. Ten healthy male volunteers served as controls. Semen analysis was carried out according to 2010 WHO manual, whereas seminal sORP was measured using the MiOXSYS platform. SDF was assessed by sperm chromatin structure assay. Participants with DFI >15% underwent a three-month lifestyle intervention program, primarily based on diet and exercise, combined with oral antioxidant therapy using multivitamins, coenzyme Q10, omega-3, and oligo-elements. We assessed changes in semen parameters, DFI, and sORP, and compared DFI results to those of volunteers obtained two weeks apart. Spearman rank correlation tests were computed for sORP and DFI results.

RESULTS

Thirty-eight (40.8%) patients had DFI >15%, of whom 31 participated in the intervention program. A significant decrease in median DFI from 25.8% to 18.0% was seen after the intervention (P <0.0001). The mean DFI decrease was 7.2% (95% CI: 4.8-9.5%; P <0.0001), whereas it was 0.42% (95%CI; -4.8 to 5.6%) in volunteers (P <0.00001). No differences were observed in sperm parameters and sORP. Based on paired sORP and DFI data from 86 patients, no correlation was observed between sORP and DFI values (rho=0.03).

CONCLUSION

A 3-month lifestyle intervention program combined with antioxidant therapy reduced DFI in infertile men with elevated SDF and a history of failed IVF/ICSI. A personalized lifestyle and antioxidant intervention could improve fertility of subfertile couples through a reduction in DFI, albeit controlled trials evaluating reproductive outcomes are needed before firm conclusions can be made. Trial registration number and date: clinicaltrials.gov NCT03898752, April 2, 2019.

The combined effect of lifestyle intervention and antioxidant therapy on sperm DNA fragmentation and seminal oxidative stress in IVF patients: a pilot study

PURPOSE

Sperm DNA fragmentation (SDF) and seminal oxidative stress are emerging measurable factors in male factor infertility, which interventions could potentially reduce. We evaluated (i) the impact of lifestyle changes combined with oral antioxidant intake on sperm DNA fragmentation index (DFI) and static oxidation-reduction potential (sORP), and (ii) the correlation between DFI and sORP.

MATERIALS AND METHODS

We conducted a prospective study involving 93 infertile males with a history of failed IVF/ICSI. Ten healthy male volunteers served as controls. Semen analysis was carried out according to 2010 WHO manual, whereas seminal sORP was measured using the MiOXSYS platform. SDF was assessed by sperm chromatin structure assay. Participants with DFI >15% underwent a three-month lifestyle intervention program, primarily based on diet and exercise, combined with oral antioxidant therapy using multivitamins, coenzyme Q10, omega-3, and oligo-elements. We assessed changes in semen parameters, DFI, and sORP, and compared DFI results to those of volunteers obtained two weeks apart. Spearman rank correlation tests were computed for sORP and DFI results.

RESULTS

Thirty-eight (40.8%) patients had DFI >15%, of whom 31 participated in the intervention program. A significant decrease in median DFI from 25.8% to 18.0% was seen after the intervention (P <0.0001). The mean DFI decrease was 7.2% (95% CI: 4.8-9.5%; P <0.0001), whereas it was 0.42% (95%CI; -4.8 to 5.6%) in volunteers (P <0.00001). No differences were observed in sperm parameters and sORP. Based on paired sORP and DFI data from 86 patients, no correlation was observed between sORP and DFI values (rho=0.03).

CONCLUSION

A 3-month lifestyle intervention program combined with antioxidant therapy reduced DFI in infertile men with elevated SDF and a history of failed IVF/ICSI. A personalized lifestyle and antioxidant intervention could improve fertility of subfertile couples through a reduction in DFI, albeit controlled trials evaluating reproductive outcomes are needed before firm conclusions can be made. Trial registration number and date: clinicaltrials.gov NCT03898752, April 2, 2019.

Effects of antioxidant co-supplementation therapy on spermatogenesis dysfunction in relation to the basal oxidation-reduction potential levels in spermatozoa: A pilot study

Purpose

In this pilot study, the authors compared the effects of antioxidant co-supplementation therapy and methylcobalamin therapy in patients with impaired semen quality.

Methods

Eighty-four subjects who visited male infertility clinics and showed abnormal semen test results were randomly subjected to one of the two therapies: antioxidant co-supplementation therapy with vitamin C, vitamin E, coenzyme Q10, and flaxseed oil or methylcobalamin therapy. The oxidation-reduction potential (ORP) and 8-hydroxy-2'-deoxyguanosine levels were used as indicators of oxidative stress levels in semen. Semen analysis was also performed.

Results

The authors obtained results from 67 patients who had completed 3 months of treatment. Neither antioxidant co-supplementation therapy nor methylcobalamin therapy changed the semen parameters significantly (except for the sperm concentration, which was increased by the latter therapy). When the pre-treatment ORP value in semen was higher than the cutoff value, both therapies significantly increased the sperm concentration. The 8-hydroxy-2'-deoxyguanosine level did not yield any meaningful predictive value with regard to increased sperm concentrations.

Conclusions

Both antioxidant co-supplementation therapy and methylcobalamin therapy increased the sperm concentration in patients with impaired semen quality when the basal ORP levels in their semen were elevated.

Telomere Signaling and Maintenance Pathways in Spermatozoa of Infertile Men Treated With Antioxidants: An in silico Approach Using Bioinformatic Analysis

Telomere shortening is considered as a marker of cellular senescence and it is regulated by various signaling pathways. Sperm telomere appears to play important role in its longevity and function. Antioxidant intake has been known to prevent the shortening of telomere. In the management of male infertility, antioxidants are commonly used to counterbalance the seminal oxidative stress. It is important to understand how antioxidants treatment may modulate telomere signaling in sperm. In the current study, we have identified 377 sperm proteins regulated by antioxidants based on data mining of published literature. Bioinformatic analysis revealed involvement of 399 upstream regulators and 806 master regulators associated with differentially expressed sperm proteins. Furthermore, upstream regulator analysis indicated activation of kinases (EGFR and MAPK3) and transcription factors (CCNE1, H2AX, MYC, RB1, and TP53). Hence, it is evident that antioxidant supplementation activates molecules associated with telomere function in sperm. The outcome of this in silico study suggests that antioxidant therapy has beneficial effects on certain transcription factors and kinases associated with sperm telomere maintenance and associated signaling pathways that may play an important role in the management of male factor infertility.

Highly Cited Articles in the Field of Male Infertility and Antioxidants: A Scientometric Analysis

PURPOSE

The objective of this scientometric analysis was to recognize the top 100 cited articles on 'Male infertility and Antioxidants' and analyze its publication characteristics.

MATERIALS AND METHODS

The Scopus database was used to retrieve related articles and the top 100 identified based on citation rate.

RESULTS

The articles were published in 56 journals between 1995 and 2019 with a median (interquartile range) citation score of 17 (5-62). Among the top 100 articles, 69 were clinical studies, which included controlled and blinded (33.33%), prospective (27.54%), randomized-controlled trials (26.09%), uncontrolled (11.59%), and retrospective (1.45%) studies. In addition to conventional semen parameters, advanced sperm function tests such as oxidative stress (51%) and sperm DNA damage (23%) were reported. Pregnancy rate (33%) was found to be the most reported reproductive outcome. Antioxidant therapy was mostly investigated in male cohorts with sperm abnormalities such as asthenozoospermia (28%) and clinical conditions such as idiopathic male infertility (20%), varicocele/varicocelectomy (17%) and general male infertility (16%).

CONCLUSIONS

The most influential publications on antioxidants and male infertility were identified for the first time in the literature. This will serve as a reliable source of information for researchers and clinicians alike.

Redox Balance in Male Infertility: Excellence through Moderation-"Μέτρον ἄριστον"

Male infertility, a relatively common and multifactorial medical condition, affects approximately 15% of couples globally. Based on WHO estimates, a staggering 190 million people struggle with this health condition, and male factor is the sole or contributing factor in roughly 20–50% of these cases. Nowadays, urologists are confronted with a wide spectrum of conditions ranging from the typical infertile male to more complex cases of either unexplained or idiopathic male infertility, requiring a specific patient-tailored diagnostic approach and management. Strikingly enough, no identifiable cause in routine workup can be found in 30% to 50% of infertile males. The medical term male oxidative stress infertility (MOSI) was recently coined to describe infertile men with abnormal sperm parameters and oxidative stress (OS), including those previously classified as having idiopathic infertility. OS is a critical component of male infertility, entailing an imbalance between reactive oxygen species (ROS) and antioxidants. ROS abundance has been implicated in sperm abnormalities, while the exact impact on fertilization and pregnancy has long been a subject of considerable debate. In an attempt to counteract the deleterious effects of OS, urologists resorted to antioxidant supplementation. Mounting evidence indicates that indiscriminate consumption of antioxidants has led in some cases to sperm cell damage through a reductive-stress-induced state. The “antioxidant paradox”, one of the biggest andrological challenges, remains a lurking danger that needs to be carefully avoided and thoroughly investigated. For that reason, oxidation-reduction potential (ORP) emerged as a viable ancillary tool to basic semen analysis, measuring the overall balance between oxidants and antioxidants (reductants). A novel biomarker, the Male infertility Oxidative System (MiOXSYS^®), is a paradigm shift towards that goal, offering a quantification of OS via a quick, reliable, and reproducible measurement of the ORP. Moderation or “Μέτρον” according to the ancient Greeks is the key to successfully safeguarding redox balance, with MiOXSYS^® earnestly claiming its position as a guarantor of homeostasis in the intracellular redox milieu. In the present paper, we aim to offer a narrative summary of evidence relevant to redox regulation in male reproduction, analyze the impact of OS and reductive stress on sperm function, and shed light on the “antioxidant paradox” phenomenon. Finally, we examine the most up-to-date scientific literature regarding ORP and its measurement by the recently developed MiOXSYS^® assay.

Oxidative Stress and Male Fertility: Role of Antioxidants and Inositols

Infertility is defined as a couple’s inability to conceive after at least one year of regular unprotected intercourse. This condition has become a global health problem affecting approximately 187 million couples worldwide and about half of the cases are attributable to male factors. Oxidative stress is a common reason for several conditions associated with male infertility. High levels of reactive oxygen species (ROS) impair sperm quality by decreasing motility and increasing the oxidation of DNA, of protein and of lipids. Multi-antioxidant supplementation is considered effective for male fertility parameters due to the synergistic effects of antioxidants. Most of them act by decreasing ROS concentration, thus improving sperm quality. In addition, other natural molecules, myo-inositol (MI) and d-chiro–inositol (DCI), ameliorate sperm quality. In sperm cells, MI is involved in many transduction mechanisms that regulate cytoplasmic calcium levels, capacitation and mitochondrial function. On the other hand, DCI is involved in the downregulation of steroidogenic enzyme aromatase, which produces testosterone. In this review, we analyze the processes involving oxidative stress in male fertility and the mechanisms of action of different molecules.

Coenzyme Q10 and Male Infertility: A Systematic Review

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.

A Global Survey of Reproductive Specialists to Determine the Clinical Utility of Oxidative Stress Testing and Antioxidant Use in Male Infertility

Purpose

The use of antioxidants is common practice in the management of infertile patients. However, there are no established guidelines by professional societies on antioxidant use for male infertility.

Materials and Methods

Using an online survey, this study aimed to evaluate the practice pattern of reproductive specialists to determine the clinical utility of oxidative stress (OS) testing and antioxidant prescriptions to treat male infertility.

Results

Responses from 1,327 participants representing 6 continents, showed the largest participant representation being from Asia (46.8%). The majority of participants were attending physicians (59.6%), with 61.3% having more than 10 years of experience in the field of male infertility. Approximately two-thirds of clinicians (65.7%) participated in this survey did not order any diagnostic tests for OS. Sperm DNA fragmentation was the most common infertility test beyond a semen analysis that was prescribed to study oxidative stress-related dysfunctions (53.4%). OS was mainly tested in the presence of lifestyle risk factors (24.6%) or sperm abnormalities (16.3%). Interestingly, antioxidants were prescribed by 85.6% of clinicians, for a duration of 3 (43.7%) or 3–6 months (38.6%). A large variety of antioxidants and dietary supplements were prescribed, and scientific evidence were mostly considered to be modest to support their clinical use. Results were not influenced by the physician's age, geographic origin, experience or training in male infertility.

Conclusions

This study is the largest online survey performed to date on this topic and demonstrates 1) a worldwide understanding of the importance of this therapeutic option, and 2) a widely prevalent use of antioxidants to treat male infertility. Finally, the necessity of evidence-based clinical practice guidelines from professional societies is highlighted.

Lack of trusted diagnostic tools for undetermined male infertility

Semen analysis is the cornerstone of evaluating male infertility, but it is imperfect and insufficient to diagnose male infertility. As a result, about 20% of infertile males have undetermined infertility, a term encompassing male infertility with an unknown underlying cause. Undetermined male infertility includes two categories: (i) idiopathic male infertility-infertile males with abnormal semen analyses with an unknown cause for that abnormality and (ii) unexplained male infertility-males with "normal" semen analyses who are unable to impregnate due to unknown causes. The treatment of males with undetermined infertility is limited due to a lack of understanding the frequency of general sperm defects (e.g., number, motility, shape, viability). Furthermore, there is a lack of trusted, quantitative, and predictive diagnostic tests that look inside the sperm to quantify defects such as DNA damage, RNA abnormalities, centriole dysfunction, or reactive oxygen species to discover the underlying cause. To better treat undetermined male infertility, further research is needed on the frequency of sperm defects and reliable diagnostic tools that assess intracellular sperm components must be developed. The purpose of this review is to uniquely create a paradigm of thought regarding categories of male infertility based on intracellular and extracellular features of semen and sperm, explore the prevalence of the various categories of male factor infertility, call attention to the lack of standardization and universal application of advanced sperm testing techniques beyond semen analysis, and clarify the limitations of standard semen analysis. We also call attention to the variability in definitions and consider the benefits towards undetermined male infertility if these gaps in research are filled.

Utility of Antioxidants in the Treatment of Male Infertility: Clinical Guidelines Based on a Systematic Review and Analysis of Evidence

It is widely accepted that oxidative stress plays an important role in the pathophysiology of male infertility and that antioxidants could have a significant role in the treatment of male infertility. The main objectives of this study are: 1) to systematically review the current evidence for the utility of antioxidants in the treatment of male infertility; and 2) propose evidence-based clinical guidelines for the use of antioxidants in the treatment of male infertility. A systematic review of the available clinical evidence was performed, with articles published on Scopus being manually screened. Data extracted included the type of antioxidant used, the clinical conditions under investigation, the evaluation of semen parameters and reproductive outcomes. The adherence to the Cambridge Quality Checklist, Cochrane Risk of Bias for randomized controlled trials (RCTs), CONSORT guidelines and JADAD score were analyzed for each included study. Further, we provided a Strength Weakness Opportunity Threat (SWOT) analysis to analyze the current and future value of antioxidants in male infertility. Of the 1,978 articles identified, 97 articles were included in the study. Of these, 52 (53.6%) were uncontrolled (open label), 12 (12.4%) unblinded RCTs, and 33 (34.0%) blinded RCTs, whereas 44 (45.4%) articles tested individual antioxidants, 31 (32.0%) a combination of several products in variable dosages, and 22 (22.6%) registered antioxidant products. Based on the published evidence, we 1) critically examined the necessity of additional double-blind, randomized, placebo-controlled trials, and 2) proposed updated evidence-based clinical guidelines for antioxidant therapy in male infertility. The current systematic review on antioxidants and male infertility clearly shows that antioxidant supplementation improves semen parameters. In addition, it provides the indications for antioxidant treatment in specific clinical conditions, including varicocele, unexplained and idiopathic male infertility, as well as in cases of altered semen quality.

Oxidative stress and male infertility

BACKGROUND

Between 30% and 80% of patients with male infertility produce excessive reactive oxygen species (ROS) in their ejaculate even though the cause of male infertility is unexplained in approximately half of cases. The strong connection between oxidative stress (OS) and male infertility has led recent investigators to propose the term "Male Oxidative Stress Infertility (MOSI)" to describe OS-associated male infertility.

METHODS

We searched the PubMed database for original and review articles to survey the effects of OS on male infertility, and then verified the effects and treatments.

MAIN FINDINGS

Seminal plasma contains many antioxidants that protect sperm from ROS, because low amounts of ROS are required in the physiological fertilization process. The production of excessive ROS causes OS which can lower fertility through lipid peroxidation, sperm DNA damage, and apoptosis. Several assays are available for evaluating OS, including the MiOXSYS® analyzer to measure oxidation-reduction potential. Several measures should be considered for minimizing OS and improving clinical outcomes.

CONCLUSION

Accurately diagnosing patients with MOSI and identifying highly sensitive biomarkers through proteomics technology is vital for better clinical outcomes.

Normal sperm parameters per se do not reliably account for fertility: A case-control study in the real-life setting

A proportion of men are infertile despite having normal medical history/physical examination and normal semen analysis. We aimed to assess whether normal sperm parameters per se account for male factor fertility. 1,957 infertile men were compared with 103 age-comparable fertile controls. Semen analysis was based on 2010 World Health Organization reference criteria. Of all, 12.1% of infertile men and 40.8% of fertile men presented with normal sperm parameters. Among fertile men, 36.9% had isolated sperm abnormalities and 22.3% men showed two or more concomitant sperm abnormalities. Serum total testosterone was higher in infertile men with normal sperm parameters compared to those with ≥2 sperm abnormalities or azoospermia, but similar to those with isolated sperm abnormalities (p ≤ .001). Circulating hormones were similar among sperm parameters groups in fertile men. At multivariable analyses, testicular volume (OR 1.12, p ≤ .001) and FSH (OR 0.8, p ≤ .001) were associated with normal sperm parameters. Overall, the longer the infertility period, the greater the number of sperm parameters abnormalities (p < .01). In conclusion, we found that 12% of infertile men and only 41% of fertile men present with normal sperm parameters. Normal sperm parameters per se do not reliably account for fertility in the real-life setting.

Scientific landscape of oxidative stress in male reproductive research: A scientometric study

Unraveling the role of reactive oxygen species and associated oxidative stress (OS) in male reproduction is one of the key areas of male reproductive research. This article illustrates the scientific landscape of OS in male reproductive research over the past several decades (1941-2018) using a scientometric approach. Scientometric data (articles per year, authors, affiliations, journals, and countries) on OS related to male reproduction were retrieved from the Scopus database and analyzed for each decade. Our analysis revealed an increasing trend in OS-based male reproductive research from 1941 to 2018 with a steep raise in publications and research collaborations starting from the period 1991-2000 (R² = 0.81). Semen abnormalities and varicocele were the major areas investigated in relation to OS with the highest positive trend in publications from the time interval 1981-1990 to 2011-2018. Analysis of publications based on OS assessment techniques revealed chemiluminescence (n = 180) and evaluation of antioxidants (n = 300) as the most widely used direct and indirect tests, respectively. Furthermore, prognostic/diagnostic studies on OS evaluation increased significantly over the time. Our analysis highlights the evolution of OS in male reproductive research and its emergence as an important prognostic and diagnostic tool in the evaluation of male infertility.

The role of infections and leukocytes in male infertility

Declining birth rates are one of the problems facing society today. Male counterparts are responsible for about half of the infertility cases, and genitourinary tract infections may play a contributing role in approximately 15% of male infertility cases. Leukocytospermia is an established indicator of infection in the male urogenital tract, although other microorganisms such as bacteria and virus may also be contributors to the etiology of male infertility. The pathophysiology of these infectious agents may be initiated by a local inflammatory reaction resulting in an increase in reactive oxygen species (ROS). This results in testicular injury, thereby affecting sperm morphology, sperm motility, sperm viability and elevation of the seminal leukocyte as a result of the genital tract infection. The infectious and inflammatory changes can result in male infertility. It is proposed that high concentrations of seminal leukocyte and infectious agents may affect sperm function resulting in clumping of motile spermatozoa, decreasing acrosomal functionality and also causing alterations in sperm morphology. However, the literature has poorly clarified the role of infection in male infertility, provoking further debate and research on this topic.

Mitigating the Effects of Oxidative Sperm DNA Damage

Sperm DNA damage is correlated with reduced embryo development and increased miscarriage risk, reducing successful conception. Given its links with oxidative stress, antioxidants have been investigated as a potential treatment, yet results are conflicting. Importantly, individual antioxidants are not identical in composition, and some compounds may be more effective than others. We investigated the use of the polyphenol-rich, high-antioxidant-capacity fruit acai as a treatment for elevated sperm DNA fragmentation (>16%), measured by terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL). Following ≥ 74 days of treatment, we observed a significant decrease in sperm DNA fragmentation (-17.0% ± 2.5%) to 11.9 ± 1.7% (0-37%), with a 68.6% success rate (defined as post-treatment TUNEL < 16%). Post-treatment decreases in DNA fragmentation and success rates were not significantly impacted by low motility and/or concentration, or exceptionally high (> 25%) TUNEL. Treatment significantly reduced concentration in men with normal semen parameters, but 88% remained normal. Overall, successful treatment was not associated with age, semen parameters or TUNEL result at baseline. However, body mass index was significantly higher in nonresponders at baseline. This study provides evidence of a low-cost, effective treatment for elevated sperm DNA damage using acai.