Increased levels of oxidants and reduced antioxidants in semen of infertile men with varicocele

The Influence of Lifestyle on Male Fertility in the Context of Insulin Resistance-Identification of Factors That Influence Semen Quality

Background: Male fertility is known to have been negatively influenced by the progress of civilization. Another condition whose incidence has been on the increase for the same reason is insulin resistance (IR). In addition, men increasingly often resign from the pursuit of active forms of leisure, preferring more sedentary ones. Considering these trends, this aim of this study was to investigate the relationships between lifestyle factors, insulin resistance, and male fertility in men with and without the condition. A further aim was to select those lifestyle factors that would make it possible to predict the level of male fertility, especially when IR is concerned. Methods: This study was performed in a group of 73 participants, divided into groups based on their insulin resistance status. Their physical activity, diet, perceived stress, sleep quality, libido level, and duration of sexual abstinence were assessed on the basis of a number of parameters, including indices proposed by the authors. In addition, relevant anthropometric measurements were taken and tests related to glucose metabolism and semen quality were carried out. On the basis of these data, statistical tests were performed to establish or disprove relationships between lifestyle choices and semen quality, as measured my sperm motility. Results: The results of this study highlighted the associations between a number of parameters, i.e., micronutrient and vitamin intake, diet quality, body composition, insulin resistance, and the duration of sexual abstinence, and semen quality, as measured by sperm motility. Significantly, the presence or absence of IR was linked to male fertility. A multivariate model was developed, incorporating parameters such as the Matsuda index, vitamin intake, and sexual abstinence duration, to predict motility scores. Conclusions: This study underscores the negative impact of modern civilization's lifestyle choices on male fertility. Notably, vitamin and mineral consumption, especially from antioxidant-rich diets like the Mediterranean diet, emerged as key modifiable factors affecting fertility. Routine diagnostics for insulin resistance in fertility-related interventions is recommended. This study also highlights the importance of considering sexual abstinence duration during semen collection for accurate diagnostic results. Future research should focus on validating the proposed multivariate model and exploring the effects of lifestyle modifications, particularly vitamin supplementation, on fertility outcomes in men, especially in the context of IR.

Investigation of sperm hsa-mir-145-5p and MLH1 expressions, seminal oxidative stress and sperm DNA fragmentation in varicocele

BACKGROUND

Mechanisms by which varicocele causes infertility are not clear and few studies have reported that some miRNAs show expression alterations in men with varicocele. Recently, sperm promoter methylation of MLH1 has been shown to be higher in men diagnosed with varicocele. This study aimed to assess the potential effects of miR-145, which was determined to target MLH1 mRNA in silico on sperm quality and function in varicocele.

METHODS

Sperm miR-145 and MLH1 expressions of six infertile men with varicocele (Group 1), nine idiopathic infertile men (Group 2), and nine fertile men (control group) were analyzed by quantitative PCR. Sperm DNA fragmentation was evaluated by TUNEL and the levels of seminal oxidative damage and total antioxidant capacity were analyzed by ELISA.

RESULTS

Our results have shown that sperm expression of miR-145 was decreased in Group 1 compared to Group 2 (P = 0.029). MLH1 expression was significantly higher in Group 2 than the controls (P = 0.048). Total antioxidant level and sperm DNA fragmentations of Group 1 and Group 2 were decreased (P = 0.001 and P = 0.011, respectively). Total antioxidant capacity was positively correlated with sperm concentration (ρ = 0.475, P = 0.019), total sperm count (ρ = 0.427, P = 0.037), motility (ρ = 0.716, P < 0.0001) and normal morphological forms (ρ = 0.613, P = 0.001) and negatively correlated with the seminal oxidative damage (ρ=-0.829, P = 0.042) in varicocele patients.

CONCLUSION

This is the first study investigating the expressions of sperm miR-145 and MLH1 in varicocele patients. Further studies are needed to clarify the potential effect of miR-145 on male fertility.

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.

Research progress on the role and mechanism of DNA damage repair in germ cell development

In the complex and dynamic processes of replication, transcription, and translation of DNA molecules, a large number of replication errors or damage can occur which lead to obstacles in the development process of germ cells and result in a decreased reproductive rate. DNA damage repair has attracted widespread attention due to its important role in the maintenance and regulation of germ cells. This study reports on a systematic review of the role and mechanism of DNA damage repair in germline development. First, the causes, detection methods, and repair methods of DNA damage, and the mechanism of DNA damage repair are summarized. Second, a summary of the causes of abnormal DNA damage repair in germ cells is introduced along with common examples, and the relevant effects of germ cell damage. Third, we introduce the application of drugs related to DNA damage repair in the treatment of reproductive diseases and related surgical treatment of abnormal DNA damage, and summarize various applications of DNA damage repair in germ cells. Finally, a summary and discussion is given of the current deficiencies in DNA damage repair during germ cell development and future research development. The purpose of this paper is to provide researchers engaged in relevant fields with a further systematic understanding of the relevant applications of DNA damage repair in germ cells and to gain inspiration from it to provide new research ideas for related fields.

Varicocele associated male infertility: cellular and molecular perspectives of pathophysiology

BACKGROUND

Varicocele is a common risk factor associated with reduced male fertility potential. The current understanding of varicocele pathophysiology does not completely explain the clinical manifestation of infertility. The present treatment options such as antioxidant supplementation and varicocelectomy only helps ∼35% of men to achieve spontaneous pregnancy.

OBJECTIVE

This review aims to summarize the available knowledge on cellular and molecular alterations implicated to varicocele associated male infertility and also highlights the new knowledge generated by 'Omics' technologies.

MATERIALS AND METHODS

PubMed, MEDLINE, Cochrane and Google Scholar databases are searched using different combinations of keywords (varicocele, infertile/fertile men with varicocele, cellular changes, molecular mechanisms, proteome, epigenome, transcriptome and metabolome). A total of 229 relevant human and animal studies published till 2021 were included in this review.

RESULTS

Current understanding advocates oxidative stress (OS) as a major contributory factor to the varicocele associated male infertility. Excessive OS causes alteration in testicular microenvironment and sperm DNA fragmentation which further contributes to infertility. Molecular and omics studies have identified several promising biomarkers such as AAMP, SPINT1, MKI67 (genetic markers), sperm quality and function related protein markers, global sperm DNA methylation level (epigenetic marker), Hspa2, Protamine, Gadd7, Dynlt1 and Beclin1 (mRNA markers), PRDX2, HSPA, APOA2, YKL40 (seminal protein markers), total choline and PHGDH (metabolic markers).

DISCUSSION

Mature spermatozoa harbours a plethora of molecular information in form of proteome, epigenome and transcriptome; which could provide very important clues regarding pathophysiology of varicocele associated infertility. Recent molecular and omics studies in infertile men with varicocele have identified several promising biomarkers. Upon further validation with larger and well-defined studies, some of these biomarkers could aid in varicocele management.

CONCLUSION

The present evidences suggest inclusion of OS and sperm DNA fragmentation tests could be useful to the diagnostic workup for men with varicocele. Furthermore, including precise molecular markers may assist in diagnostics and prognostics of varicocele associated male infertility. This article is protected by copyright. All rights reserved.

Oxidative Stress and Varicocele-Associated Male Infertility

Despite being regarded as one of the most common causes of male subfertility, the pathophysiology of varicocele remains largely unknown. Recently, oxidative stress (OS) is proposed to be the mediator in how varicocele may negatively impact fertility. The imbalance of reactive oxygen species (ROS) and seminal antioxidants results in damage to sperm DNA and lipid membrane. There is evidence demonstrating higher OS level in men with varicocele which is also positively correlated with clinical grading of varicocele. Moreover, a number of studies have revealed the negative correlation between OS and conventional semen parameters. Furthermore, various interventions have shown their potential in alleviating OS in men with varicocele-associated infertility. Although direct evidence on improving pregnancy rate is not available at the moment, varicocelectomy has demonstrated promising results in relieving OS. Oral antioxidants represent another option with a favourable safety profile. The supplement can be used alone or as adjunct to varicocelectomy. However, most of the studies are hampered by heterogenous dose regime and high-level evidence is lacking.

Oxidative stress and DNA damage status in couples undergoing in vitro fertilization treatment

This study examined the status of oxidative stress in 599 couples undertaking in vitro fertilization (IVF) treatment and its association with reproductive hormones, smoking, and outcomes. Oxidative stress biomarkers such as malondialdehyde, 8-hydroxy-2-deoxyguanosine, hydrogen peroxide (H₂O₂), catalase (CAT), and total antioxidant capacity (TAC) were determined in follicular fluid and seminal plasma. Tail moment (TM) was used to evaluate DNA damage in the sperm and granulosa cells. Reproductive hormones in serum and cotinine (COT) in urine, follicular fluid, and seminal plasma samples were determined. Separate multivariate linear regression was used to assess associations between levels of each oxidative stress biomarker and each hormone and smoking parameter (modeled as natural log-transformed). The findings indicate that some oxidative stress and DNA damage biomarkers played a role in disrupting certain reproductive hormones in women and their male partners either by overproducing reactive oxygen species or reducing antioxidant defense capacity. Although women were nonsmokers, COT levels > 50 and 10 µg/L in urine and follicular were observed in 5.7 and 1.7%, respectively. Levels of follicular fluid COT were positively associated with H₂O₂ and TM. We used log-binomial multivariate regression to estimate relative risks for the association between oxidative stress/DNA damage and IVF binary outcomes (fertilization rate > 50%, biochemical pregnancy, clinical pregnancy, and live birth). An increase in the CAT levels of follicular fluid was associated with a 48 and 41% decrease in the risk of poor fertilization rate (≤50%) and unsuccessful live birth, respectively. After the models were adjusted for hormonal factors, the associations remained the same, except that the elevated TAC in follicular fluid became significantly associated with a decrease of 42% in the risk of poor fertilization rate (≤50%). The higher antioxidant activity (CAT and TAC) in follicular fluid might positively impact specific IVF outcomes.

Dietary β-glucan influences the expression of testicular aquaporins, antioxidative defence genes and sperm quality traits in endangered golden mahseer, Tor putitora (Hamilton, 1822)

The effect of dietary β-glucan on seminal plasma composition, sperm characteristics, expression of aquaporins, and antioxidative defence genes of golden mahseer was evaluated. For that, four experimental diets containing 0 (control), 0.5, 1, and 1.5% β-glucan were fed to male golden mahseer brooders for 130 days. Feeding of 0.5% β-glucan was found to improve sperm characteristics, viz. sperm count, motility, viability, and morphology with no effect on gonadosomatic index and seminal plasma energy resources. The marked down-regulation in the transcript abundance of testicular aqp3a noticed in 1.5% β-glucan fed brooders corresponds to their poor sperm quality. Further, the mRNA expression of genes encoding antioxidant enzymes, namely gst and sod1, was lowest in 0.5% β-glucan fed brooders. In contrast, control and higher β-glucan (1 and 1.5%) groups displayed relatively higher expression levels of testicular gst and sod1. On the other hand, the higher seminal plasma total antioxidant capacity observed in 0.5 and 1% β-glucan fed brooders indicated increased scavenging ability of reactive oxygen species. Overall, supplementation of 0.5% β-glucan improved sperm quality and antioxidative potential, but the higher inclusion (1.5%) negatively affected sperm characteristics. Collectively, dietary β-glucan (0.5%) can be a practical approach to developing quality broodstock of golden mahseer.

Antioxidant-Based Therapies in Male Infertility: Do We Have Sufficient Evidence Supporting Their Effectiveness?

Under physiological conditions, reactive oxygen species (ROS) play pivotal roles in various processes of human spermatozoa. Indeed, semen requires the intervention of ROS to accomplish different stages of its maturation. However, ROS overproduction is a well-documented phenomenon occurring in the semen of infertile males, potentially causing permanent oxidative damages to a vast number of biological molecules (proteins, nucleic acids, polyunsaturated fatty acids of biological membrane lipids), negatively affecting the functionality and vitality of spermatozoa. ROS overproduction may concomitantly occur to the excess generation of reactive nitrogen species (RNS), leading to oxidative/nitrosative stress and frequently encountered in various human pathologies. Under different conditions of male infertility, very frequently accompanied by morpho-functional anomalies in the sperm analysis, several studies have provided evidence for clear biochemical signs of damages to biomolecules caused by oxidative/nitrosative stress. In the last decades, various studies aimed to verify whether antioxidant-based therapies may be beneficial to treat male infertility have been carried out. This review analyzed the results of the studies published during the last ten years on the administration of low-molecular-weight antioxidants to treat male infertility in order to establish whether there is a sufficient number of data to justify antioxidant administration to infertile males. An analysis of the literature showed that only 30 clinical studies tested the effects of the administration of low-molecular-weight antioxidants (administered as a single antioxidant or as a combination of different antioxidants with the addition of vitamins and/or micronutrients) to infertile males. Of these studies, only 33.3% included pregnancy and/or live birth rates as an outcome measure to determine the effects of the therapy. Of these studies, only 4 were case–control studies, and only 2 of them found improvement of the pregnancy rate in the group of antioxidant-treated patients. Additionally, of the 30 studies considered in this review, only 43.3% were case–control studies, 66.7% enrolled a number of patients higher than 40, and 40% carried out the administration of a single antioxidant. Therefore, it appears that further studies are needed to clearly define the usefulness of antioxidant-based therapies to treat male infertility.

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.

Current Insights and Latest Updates in Sperm Motility and Associated Applications in Assisted Reproduction

Spermatozoon is a motile cell with a special ability to travel through the woman’s reproductive tract and fertilize an oocyte. To reach and penetrate the oocyte, spermatozoa should possess progressive motility. Therefore, motility is an important parameter during both natural and assisted conception. The global trend of progressive reduction in the number and motility of healthy spermatozoa in the ejaculate is associated with increased risk of infertility. Therefore, developing approaches for maintaining or enhancing human sperm motility has been an important area of investigation. In this review we discuss the physiology of sperm, molecular pathways regulating sperm motility, risk factors affecting sperm motility, and the role of sperm motility in fertility outcomes. In addition, we discuss various pharmacological agents and biomolecules that can enhance sperm motility in vitro and in vivo conditions to improve assisted reproductive technology (ART) outcomes. This article opens dialogs to help toxicologists, clinicians, andrologists, and embryologists in understanding the mechanism of factors influencing sperm motility and various management strategies to improve treatment outcomes.

Varicocoele and oxidative stress: New perspectives from animal and human studies

BACKGROUND

Varicocoele (VCL), one of the main causes of male subfertility, negatively affects testicular function. Due to limited access to human testicular tissue, animal model studies have been used to evaluate molecular and, recently, epigenetic changes attributed to pathophysiology induced by VCL.

OBJECTIVES

This review aims to provide an update on the latest findings regarding the link between VCL-induced biochemical stress and molecular changes in germ cells and spermatozoa. Endocrine and antioxidant status, testicular chaperone-specific hemostasis failure, altered testicular ion balance, metabolic disorders, and altered carbon cycling during spermatogenesis are among the many features that will be presented.

DISCUSSION

Literature review coupled with our own findings suggests that ionic imbalance, hypoxia, hyperthermia, and altered blood flow could lead to severe chronic oxidative and nitrosative stress in patients with VCL leading to defective spermatogenesis and impairment of the integrity of all sperm cell components and compartments down to the epigenetic information they carry.

CONCLUSION

Since oxidative stress is an important feature of the reproductive pathology of VCL, therapeutic strategies such as the administration of appropriate antioxidants could be undertaken as a complementary non-invasive treatment line.

Transcript Isoforms of SLC7A11-AS1 Are Associated With Varicocele-Related Male Infertility

Oxidative stress is one of the crucial mediators of varicocele-related male infertility. Recently, roles of long noncoding RNAs (lncRNAs) in oxidative stress have begun to emerge, however, little is known about their role in male infertility. The aim of this study was to determine the role of lncRNA SLC7A11-AS1 in varicocele-related male infertility. Through a high-throughput bioinformatics investigation, we predicted that lncRNA SLC7A11-AS1 might be involved in this type of infertility. The reactive oxygen species (ROS) levels and expression levels of SLC7A11-AS1 isoforms were evaluated in ejaculated spermatozoa of 25 infertile men with varicocele and 17 fertile individuals as control. Isoform 6 of SLC7A11-AS1 that showed a significant elevation in infertile men with varicocele relative to the fertile group was overexpressed in testicular-derived carcinoma cell lines (NT2 and NCCIT) followed by assessment of ROS, glutathione (GSH), lipid peroxidation, and cell viability. Overexpression of SLC7A11-AS1 isoform 6 in NT2 and NCCIT cell lines resulted in a significant downregulation of SLC7A11 gene expression, which consequently decreased GSH levels and concomitantly increased ROS levels and enhanced lipid peroxidation, which jeopardized cell survival and promoted cell death. Our finding revealed a potential role of oxidative-related lncRNAs in the pathophysiology of male infertility associated with varicocele.

Increased Sperm DNA Fragmentation in Infertile Men with Varicocele: Relationship with Apoptosis, Seminal Oxidative Stress, and Spermatic Parameters

This study intends to determine the extent of nuclear sperm injury in patients with varicocele and to investigate its relationship with apoptosis and oxidative stress (OS). Ejaculated sperm samples from 51 patients diagnosed with varicocele and 29 fertile men were examined. According to the guidelines, the patient's sperm samples were classified into varicocele with normal semen parameters (n = 11) and varicocele with abnormal semen parameters (n = 40). Sperm DNA fragmentation was assessed using terminal deoxynucleotidyl transferase dUTP nick end labeling assay. The proportion of both viable and dead spermatozoa with externalized phosphatidylserine (PS) was detected by the bivariate annexin V/6-CFDA staining method. Seminal malondialdehyde (MDA) amounts and antioxidant enzymes activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were measured spectrophotometrically. Sperm DNA fragmentation, viable spermatozoa with externalized PS, and MDA levels were significantly higher in studied subgroups of patients with varicocele, either with normal or with abnormal semen parameters than controls. The seminal antioxidant enzymes activities were significantly reduced in both subgroups of patients with varicocele compared to the controls. The percentage of spermatozoa with fragmented DNA was positively correlated to the MDA level as well as the proportion of viable spermatozoa with externalized PS. However, the decreased seminal antioxidant status was negatively correlated with the increased proportion of sperm DNA fragmentation and apoptotic spermatozoa. Impaired seminal antioxidant profile and increased seminal level of lipid peroxidation may be involved in the pathophysiological mechanisms of cell death-mediated DNA breaks in patients with varicocele.

Seminal Plasma Analysis of Oxidative Stress in Different Genitourinary Topographical Regions Involved in Reproductive Tract Disorders Associated with Genital Heat Stress

The pathophysiological mechanisms responsible for male subfertility/infertility caused by or complicated by genital heat stress remains unclear in many respects. Because seminal plasma creates the environment for the proper functioning of spermatozoa, in this study, we verified the associations among standard spermiograms, seminal biochemical parameters (neutral alpha-glucosidase, fructose, and citric acid) and oxidative stress markers (total antioxidant capacity, catalase activity, superoxide dismutase activity, and malondialdehyde concentration) in distinct entities associated with male infertility with and without long-time exposure to local hyperthermia. We demonstrated that men exposed to prolonged environmental or clinically recognized local heat stress in adulthood may suffer from dysregulation of seminal antioxidant components, which can be directly associated with epididymal and prostate function. The comparative analysis of the studied parameters showed numerous correlations among all biochemical parameters (particularly neutral alpha-glucosidase) with low standard semen quality in almost all the investigated infertile groups. In light of the data obtained in this originally designed study, we conclude that more attention should be paid to the epididymis and accessory gland function in subfertile and infertile men exposed to genital heat stress, especially in the context of novel treatment algorithms (targeted therapies).

TUNEL assay-Standardized method for testing sperm DNA fragmentation

Sperm DNA integrity is important for normal functions such as fertilization, implantation, pregnancy and fetal development. Sperm DNA fragmentation (SDF) is more common in infertile men and may be responsible for poor reproductive function. Although there are a number of tests available to measure SDF, the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-nick end labelling TUNEL) assay using flow cytometry is becoming more popular to measure the sperm DNA fragmentation. It is a direct test that measures both single- and double- DNA strand breaks. In this review, we describe the protocol, quality control and measurement of sperm DNA fragmentation using a benchtop flow cytometer. We also briefly discuss the factors that can affect the results, challenges and clinical implications of TUNEL in assessing male infertility.

Endogenous and Exogenous Antioxidants As a Tool to Ameliorate Male Infertility Induced by Reactive Oxygen Species

Significance: Antioxidants are essential for the maintenance of cellular redox homeodynamics in the male reproductive tract, playing a key role in fertilizing potential. Reactive oxygen species (ROS), at physiological levels, are essential for sperm function and fertilization. Under pathological conditions, abnormal production of ROS may occur. Redox control is primarily regulated by the inner antioxidant system. However, these endogenous antioxidants may be present at abnormal amounts or may be insufficient. Exogenous antioxidants obtained through the diet may have an important role, particularly in specific pathological conditions. This review addresses the regulation of redox homeodynamics in the male reproductive tract by endogenous and exogenous antioxidants and the importance of their cooperation for the maintenance of fertility. Recent Advances: Many studies have shown the importance of antioxidants for the preservation of male fertility, mostly under pathological conditions. Excessive antioxidants can inhibit ROS-induced signaling pathways that are essential for the reproductive system. The challenge is to keep the balance between oxidants and antioxidants to maintain ROS-amount at physiological concentration. Critical Issues: Although antioxidant therapies are gaining popularity and showing promising results in the improvement of male fertility, there is a lack of knowledge regarding the type of exogenous antioxidant, the doses and time to be administered. Future Directions: It would be of great importance to find a way to restore redox homeostasis under stress conditions. Understanding the poorly studied mechanisms by which exogenous antioxidants cooperate with the inner cellular antioxidant system to counteract free radicals may help in the development of new fertility therapies.

Conventional semen analysis and advanced sperm function tests in diagnosis and management of varicocele

Clinical varicoceles are a common cause of male infertility and affect sperm parameters as measured in a conventional semen analysis. Varicocelectomy has been shown in prospective studies to improve semen parameters in men with a clinical varicocele. Clinical varicoceles are also a well-known source of oxidative stress which may affect the quality of spermatozoa. Spermatozoa are particularly susceptible to oxidative stress due to a limited capacity for DNA repair. The susceptibility of spermatozoa to oxidative stress is modulated by a balance between ROS and antioxidants, which can be quantified by various laboratory assays. Varicocelectomy has been consistently shown to reduce both ROS and sperm DNA fragmentation, and various assays should be utilised in the diagnosis and treatment of infertile men with a clinical varicocele.

Relationships between Ghrelin and Obestatin with MDA, Proinflammatory Cytokines, GSH/GSSG Ratio, Catalase Activity, and Semen Parameters in Infertile Patients with Leukocytospermia and Varicocele

Ghrelin and obestatin are involved in many biological functions including reproduction. Growing evidences suggest that both peptides could exert protective and antioxidant activities. In this study, the relationships between ghrelin/obestatin, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), malondialdehyde (MDA), reduced glutathione (GSH), oxidized glutathione (GSSG), expressed as the GSH/GSSG ratio, catalase (CAT), and semen parameters in infertile patients with varicocele or leukocytospermia and controls were investigated. Fifty-six infertile patients (32 with leukocytospermia and 24 with varicocele) and 14 controls participated in this study. Semen analysis was performed following the WHO guidelines. Apoptotic and necrotic sperm were scored by annexin V/propidium iodide assay. Seminal plasma samples were used for the following determinations: ghrelin, obestatin, IL-6, and TNF-α were measured by an immunological method, GSH/GSSG by an enzymatic method, and CAT by spectrophotometric determination. With respect to controls, both the leukocytospermia and varicocele groups showed altered sperm parameters, significantly increased sperm apoptosis (P = 0.009 and P = 0.011, respectively), IL-6 (P = 0.0001 and P = 0.004, respectively), and TNF-α levels (P = 0.0001 and P = 0.002, respectively); both groups had significantly decreased levels of ghrelin (P = 0.0001), obestatin (P = 0.0001 and P = 0.006, respectively), and GSH/GSSG ratio (P = 0.003 and P = 0.0001, respectively). The MDA concentration was significantly increased in the leukocytospermia group vs. controls (P = 0.0001), in the varicocele group vs. controls (P = 0.011), and in the leukocytospermia group vs. the varicocele group (P = 0.008). CAT activity was augmented in both the leukocytospermia and varicocele groups (P = 0.0001)vs. controls. The results indicate that both ghrelin and obestatin may play a protective role in human semen and this effect is probably due to their antioxidant properties.

Interventions to Prevent Sperm DNA Damage Effects on Reproduction

Excessive oxidation and antioxidant imbalance resulting from several conditions may cause sperm DNA damage, which, in turn, affect male fertility, both natural and assisted. Sperm DNA damage transferred to the embryo might also affect the health of offspring. Several conditions associated with excessive oxidative stress are modifiable by the use of specific treatments, lifestyle changes, and averting exposure to environmental/occupational toxicants. Here, we discuss the strategies to reduce sperm DNA damage with a focus on clinical and surgical interventions.

Potentiometry as a Tool for Monitoring of Antioxidant Activity and Oxidative Stress Estimation in Medicine

The complexity of biological objects and the rapid change in their composition after sampling, the variety of compounds of different chemical nature, possessing oxidative and antioxidant properties, make the task of its estimating extremely nontrivial and important for food, nutrients and human health characterization. The paper discusses the use of potentiometry in determining integral antioxidant/oxidant activity mainly of biological fluids and human skin. The source of information is the electrode potential shift that occurs when the analyzed object is inserted in the solution of the mediator system or when the mediator system is exposed to human skin. The experimental approaches, protocols, calculations are described. A number of examples of antioxidant activity and oxidative stress estimation in medicine are presented. The works show lower levels of antioxidant activity (AOA) of plasma and blood serum in patients with cardiovascular diseases, obesity, and malignant neoplasms as compared with the healthy volunteers. It was found out that antioxidant activity of fertile men semen is higher than AOA of infertile patients. Using the method discussed have shown that in some infertile male patients antioxidant activity of semen has been accompanied by oxidant activity. It has been found, that antioxidant activity of skin increases after intake of ascorbic acid and vitamin-enriched juices. The described approach holds considerable promise for monitoring oxidative stress of the whole organism and its systems, and for selecting effective and safe therapy. Thus, it opens up new opportunities in expanding the use of analytical chemistry in such an important field as medicine.

Thiol-disulphide homoeostasis as an oxidative stress marker in men with varicocele

Oxidative stress is the most common factor leading to infertility in men with varicocele. Reactive oxygen species and other markers of oxidative stress are measured to predict the extent of oxidative stress. Thiol groups are important antioxidants and essential molecules protecting organism against the harmful effects of reactive oxygen species. Thiol-disulphide homoeostasis is a unique, easy and new method to demonstrate oxidative stress. The aim of this study was to determine thiol-disulphide homoeostasis as an oxidative stress marker in infertile men with varicocele. The hormonal profile and parameters of thiol-disulphide homoeostasis were studied in 46 infertile men with varicocele, 70 fertile men with varicocele and 37 fertile controls. Infertile men with varicocele had significantly higher disulphide concentrations and disulphide/native thiol, disulphide/total thiol and native/total thiol ratios than those of fertile men with varicocele and fertile controls. According to these results, the blood plasma of patients with varicocele contains excessive oxidative stress, even in men with normospermia, and therefore, thiol-disulphide homoeostasis may be useful as an oxidative stress marker in men with varicocele.

Chrysin Administration Protects against Oxidative Damage in Varicocele-Induced Adult Rats

Oxidative stress is known as the leading factor responsible for varicocele-related infertility and for that reason, many antioxidant therapies have been proposed. Considering that, we evaluated the reproductive outcomes and fertility of varicocelized rats and the impact of chrysin within these parameters. The animals were allocated into three groups: sham (control), varicocele treated via gavage with 50 mg/kg/day of chrysin (V1), or vehicle (V2) for 56 days. Chrysin treatment prevented oxidative damage resulting from varicocele by decreasing testicular concentrations of malondialdehyde and sperm DNA fragmentation. It also improved histological aspect of the testis and maintained morphometric parameters similar to the sham group. Furthermore, there were no differences in body and reproductive organ weights, histopathological analysis of epididymis, sperm counts and morphology, testosterone levels, sexual behavior, and fertility parameters among experimental groups. Our results reinforce the idea that injuries provoked by experimental varicocele are related, at least in part, to oxidative stress. Moreover, varicocele showed bilateral deleterious effects without interfering with fertility. Chrysin administration significantly ameliorated sperm parameters, protecting the reproductive system against varicocele damages. For that reason, chrysin might be an alternative adjuvant therapy to improve sperm quality in men presenting this condition.

Laboratory tests for oxidative stress

INTRODUCTION

Oxidative stress (OS) is considered a significant contributor to male infertility. A number of laboratory techniques have been developed to evaluate oxidative stress in the semen. We review these tests and their current use.

METHODS

A literature review was performed utilizing the PubMed search engine for articles studying OS etiology and impact on male fertility, and the laboratory tests used in its assessment.

RESULTS

The state of OS results from exaggerated production of oxygen-derived free radicals, also known as reactive oxygen species, to an extent overwhelming the body's antioxidant defense mechanisms. Several laboratory tests have been utilized in OS measurement during male fertility evaluation. These tests are classified into direct assays which measure the degree of oxidation within a sperm cell and indirect assays which estimate the detrimental effects of OS. The chemiluminescence assay, flow cytometry, nitroblue tetrazolium assay, and cytochrome c reduction are examples of direct assays while the myeloperoxidase test and measurements of lipid peroxidation, oxidation-reduction potential, and total antioxidant capacity are examples of the indirect assays.

CONCLUSION

OS measurement is an important tool that may help in understanding the pathophysiology of male infertility and provide valuable information that would guide treatment decisions and patient follow-up.

Specialized sperm function tests in varicocele and the future of andrology laboratory

Varicocele is a common medical condition entangled with many controversies. Though it is highly prevalent in men with infertility, still it marks its presence in males who do have normal fertility. Determining which patients are negatively affected by varicocele would enable clinicians to better select those men who benefitted the most from surgery. Since conventional semen analysis has been limited in its ability to evaluate the negative effects of varicocele on fertility, a multitude of specialized laboratory tests have emerged. In this review, we examine the role and significance of specialized sperm function tests with regards to varicocele. Among the various tests, analysis of sperm DNA fragmentation and measurements of oxidative stress markers provide an independent measure of fertility in men with varicocele. These diagnostic modalities have both diagnostic and prognostic information complementary to, but distinct from conventional sperm parameters. Test results can guide management and aid in monitoring intervention outcomes. Proteomics, metabolomics, and genomics are areas; though still developing, holding promise to revolutionize our understanding of reproductive physiology, including varicocele.

Effect of varicocele on semen characteristics according to the new 2010 World Health Organization criteria: a systematic review and meta-analysis

This study investigated the effects of varicocele on semen parameters in infertile men based on the new 2010 World Health Organization laboratory manual for the examination of human semen. Semen analysis results (volume, sperm count, motility, and morphology) were the primary outcomes. An electronic search to collect the data was conducted using the Medline/PubMed, SJU discover, and Google Scholar databases. We searched articles published from 2010 to August 2015, i.e., after the publication of the 2010 WHO manual. We included only those studies that reported the actual semen parameters of adult infertile men diagnosed with clinical varicocele and contained a control group of either fertile men or normozoospermic men who were not diagnosed with varicocele. Ten studies were included in the meta-analysis, involving 1232 men. Varicocele was associated with reduced sperm count (mean difference: −44.48 × 10⁶ ml⁻¹; 95% CI: −61.45, −27.51 × 10⁶ ml⁻¹; P < 0.001), motility (mean difference: −26.67%; 95% CI: −34.27, −19.08; P < 0.001), and morphology (mean difference: −19.68%; 95% CI: −29.28, −10.07; P < 0.001) but not semen volume (mean difference: −0.23 ml; 95% CI: −0.64, 0.17). Subgroup analyses indicated that the magnitude of effect was influenced by control subtype but not WHO laboratory manual edition used for semen assessment. We conclude that varicocele is a significant risk factor that negatively affects semen quality, but the observed pooled effect size on semen parameters does not seem to be affected by the WHO laboratory manual edition. Given most of the studies published after 2010 still utilized the 1999 manual for semen analysis, further research is required to fully understand the clinical implication of the 2010 WHO laboratory manual on the association between varicocele and semen parameters.

Comparison of Before and After Varicocelectomy Levels of Trace Elements, Nitric Oxide, Asymmetric Dimethylarginine and Malondialdehyde in the Seminal Plasma and Peripheral and Spermatic Veins

Increased oxidative damage has been suggested to play an important role in the spermatogenesis and sperm function changes in patients with varicocele. However, changes in levels of nitric oxide (NO), asymmetric dimethylarginine (ADMA), malondialdehyde (MDA), iron (Fe), zinc (Zn) and copper (Cu) in blood and seminal plasma, and semen quality, are unknown. The aim of this study was to investigate the NO, ADMA, Fe, Cu, Zn and MDA levels from seminal plasma and peripheral and spermatic vein blood samples of patients with varicocele before and after varicocelectomy. In this before and after comparative study, 29 consecutive patients attending a training hospital in Tekirdag, Turkey, were recruited. MDA and NO levels were determined by spectrophotometric methods. The levels of ADMA were determined by enzyme-linked immunosorbent assay method. Trace element level was determined by atomic absorption spectrophotometric method. The levels of MDA in the seminal plasma and peripheral and spermatic vein samples were observed to decrease significantly in the comparison of before and after phases of the study group (p = 0.022, p = 0.001 and p = 0.034, respectively). Also, the levels of NO in the seminal plasma and spermatic vein samples decreased significantly in the comparison of before and after phases of the study group (p = 0.025 and p = 0.001, respectively), while the levels of ADMA in seminal plasma and spermatic vein samples increased significantly in the comparison of before and after phases of the study group (p = 0.003 and p = 0.001, respectively). There were no significant differences in the levels of trace elements and sperm count (p > 0.05). Oxidative stress is significantly higher in the spermatic vein and seminal plasma samples of patients with varicocele before varicocelectomy. In conclusion, these events may be evaluated accordingly for the potentially beneficial treatment methods.

Iron and copper in male reproduction: a double-edged sword

Iron and copper are essential trace nutrients playing important roles in general health and fertility. However, both elements are highly toxic when accumulating in large quantities. Their direct or indirect impact on the structure and function of male gonads and gametes is not completely understood yet. Excess or deficiency of either element may lead to defective spermatogenesis, reduced libido, and oxidative damage to the testicular tissue and spermatozoa, ultimately leading to fertility impairment. This review will detail the complex information currently available on the dual roles iron and copper play in male reproduction.

Sperm quality after density gradient centrifugation with three commercially available media: a controlled trial

BACKGROUND

Density gradient is the preferred technique for sperm processing for ART. However, no study has examined sperm quality using different processing media simultaneously and under identical conditions. Therefore, we evaluated semen quality following sperm preparation by three commonly used commercially available density gradient media in a well-designed controlled trial.

METHODS

We obtained semen samples from 20 healthy volunteers. Percent motility, total motile sperm (TMS), % recovery and DNA damage were assessed before and after separation in three different sperm density gradient media-PureCeption, ISolate and SpermGrad-125.

RESULTS

Percent motility was higher in the ISolate (81.4% ± 6.6%) and SpermGrad-125 samples (85.7% ± 8.0%) (P < 0.0001) than in the PureCeption samples (62.5% ± 13.2%) (P = 0.07). TMS was higher in the PureCeption(TM) and ISolate samples (14.2% ± 15.9% and 15.8% ± 18.2%) than in those prepared with SpermGrad-125 (10.6% ± 19.7%) (P < 0.0001). Percent recovery was significantly higher in the PureCeption(TM) and ISolate samples (45.3% and 48.9%) than in the SpermGrad-125(TM) samples (30.8%) (P < 0.01). DNA fragmentation was comparable across the three gradients (PureCeption = 8.8% ± 4.7%; ISolate = 7.2 ± 5.2% and SpermGrad-125 = 11.2% ± 7.4%).

CONCLUSIONS

Three different density gradient processing media PureCeption, ISolate, and SpermGrad-125 were examined for their effects on sperm quality. Sperm processed by ISolate and Sperm Grad 125 had better motility and TMS after processing. The extent of DNA damage was comparable in all three gradients.

Role of varicocele repair for male infertility in the era of assisted reproductive technologies

Varicocele is an abnormal condition characterized by dilatation of the pampiniform plexus veins draining the testis and is present in 15 % of men. Varicoceles have an adverse effect on spermatogenesis and are the most common cause of male infertility. Approximately 35 % of infertile men and more than 70 % of men with secondary infertility were reported to have varicoceles. Although data on methods of varicocele repair are accumulating, there remains controversy regarding the indications and techniques for varicocele repair. In addition, the role of varicocele repair in this era of assisted reproductive technologies continues to be debated. In this study, we performed a comprehensive PubMed search in order to review the current status of varicocele repair for male infertility. We reviewed English-language studies published from 1992 through 2013. After reviewing the articles, we identified a recent meta-analysis of four randomized controlled trials, which found that varicocele repair for oligozoospermic men was associated with better pregnancy rates as compared with observation. Our review of prospective studies showed that all semen parameters, including sperm concentration, motility, and progressive motility, were significantly improved after varicocele repair. We also summarize the findings of recent studies reporting beneficial effects of varicocele repair, i.e., decreased oxidative stress and sperm DNA fragmentation after varicocele repair and superior cost effectiveness versus in vitro fertilization/intracytoplasmic sperm injection alone, which may be important in the era of assisted reproductive technologies. Varicocele repair is a widespread, well-established procedure that can improve semen parameters in men with infertility. The effect of such treatment on the pregnancy rate is unclear because evidence is limited due to difficulties in recruiting patients for studies. Among the repair techniques, microsurgical repair using a subinguinal approach is potentially the best practice, although this procedure requires training in microsurgery. All these topics require further research in studies with sufficient patient enrollment and follow-up.

Male infertility: non-surgical therapy

Infertility is defined as the inability of a couple to conceive after 12 months of unprotected intercourse and affects 15% of couples with male component of 50%. The failure of spermatogenesis can result from hypothalamic, pituitary or testicular disorders although in the majority of cases it remains idiopathic. The diagnostic process includes medical history, semen analysis, hormonal studies, genetic studies and radiological evaluation.

Targeted hormonal therapies are available for patients whose infertility is caused by altered levels of androgens, prolactin, or TSH. Main treatments aim to restore normal sexual function by administering testosterone and to increase spermatogenesis with pulsatile GnRH.

Fertility in men suffering from hypogonadotrophic hypogonadism can be restored through hormone therapy using GnRH or with the use of gonadotropins when there is hypothalamic failure. In the past, treatment options for the factors of idiopathic male infertility were mainly based on the use of anti-estrogens that cause an increased secretion of FSH and LH and therefore of testosterone.

Oxytocin promotes the progression of the sperm and increases the conversion of testosterone into dihydrotestosterone. The aromatase's inhibitors decrease the conversion of androgens to estrogens, increasing serum levels of androgens, resulting in an increased release of gonadotropins.

Two areas showed interesting future perspectives for the treatment of infertility: gene therapy and transplantation of spermatogonial stem cells.

Study of the effects of oral zinc supplementation on peroxynitrite levels, arginase activity and NO synthase activity in seminal plasma of Iraqi asthenospermic patients

BACKGROUND

Low concentrations of nitric oxide (NO) are necessary for the biology and physiology of spermatozoa, but high levels of NO are toxic and have negative effects on sperm functions. Although several studies have considered the relationship between infertility and semen NO concentrations, no study on the effects of asthenospermia treatments such as oral zinc supplementation on concentrations of NO, which are important in fertility, has been reported. Studies have shown that oral zinc supplementation develops sperm count, motility and the physical characteristics of sperm in animals and in some groups of infertile men. The present study was conducted to study the effect of zinc supplementation on the quantitative and qualitative characteristics of semen, along with enzymes of the NO pathway in the seminal plasma of asthenospermic patients.

METHODS

Semen samples were obtained from 60 fertile and 60 asthenozoospermic infertile men of matched age. The subfertile group was treated with zinc sulfate; each participant took two capsules (220 mg per capsule) per day for 3 months. Semen samples were obtained (before and after zinc sulfate supplementation). After liquefaction of the seminal fluid at room temperature, routine semen analyses were performed. The stable metabolites of NO (nitrite) in seminal plasma were measured by nitrophenol assay. Arginase activity and NO synthase activity were measured spectrophotometrically.

RESULTS

Peroxynitrite levels, arginase activity, NO synthase activity and various sperm parameters were compared among fertile controls and infertile patients (before and after treatment with zinc sulfate). Peroxynitrite levels and NO synthase activity were significantly higher in the infertile patients compared to the fertile group. Conversely, arginase activity was significantly higher in the fertile group than the infertile patients. Peroxynitrite levels, arginase activity and NO synthase activity of the infertile patient were restored to normal values after treatment with zinc sulfate. Volume of semen, progressive sperm motility percentage and total normal sperm count were increased after zinc supplementation.

CONCLUSIONS

Treatment of asthenospermic patients with zinc supplementation leads to restored peroxynitrite levels, arginase activity and NO synthase activity to normal values and gives a statistically significant improvement of semen parameters compared with controls.

Seminal soluble fas relationship with oxidative stress in infertile men with varicocele

OBJECTIVE

To assess seminal plasma soluble Fas (sFas) relationship with oxidative stress and varicocele (Vx) grade in infertile men.

METHODS

In all, 230 men were prospectively investigated: fertile men without Vx, fertile men with Vx, infertile men without Vx, and infertile men with Vx. In their semen, seminal oxidant (malondialdehyde [MDA]), antioxidants (ascorbic acid, glutathione peroxidase [GPx], catalase [CAT], and superoxide dismutase [SOD]), and seminal sFas were assessed.

RESULTS

Either fertile or infertile men with Vx demonstrated significantly higher seminal oxidants (MDA) and significantly lower seminal antioxidants (SOD, GPx, CAT, and ascorbic acid), sFas compared with fertile or infertile men without Vx. Infertile men with or without Vx had significantly higher seminal MDA and significantly lower seminal antioxidants, sFas compared with fertile men with or without Vx. Men with Vx grade III had significantly higher seminal MDA and significantly lower antioxidants, sFas compared with Vx grade II and I, respectively. Seminal sFas demonstrated significant positive correlation with sperm count, sperm motility, sperm normal forms, seminal ascorbic acid, SOD, GPx, and CAT and significant negative correlation with seminal MDA.

CONCLUSION

Down regulation of seminal sFas in Vx associated men is related to increased oxidative stress and is correlated with Vx grade.

Is thioredoxin reductase involved in the defense against DNA fragmentation in varicocele?

We aimed to investigate the role of thioredoxin reductase (TR) and inducible heat shock protein 70 (iHsp70) and their relationship with sperm quality in varicocele (VAR) patients. Semen samples were obtained from 16 subfertile men diagnosed as VAR and 10 fertile men who applied to the Andrology Laboratory of Istanbul Medical Faculty of Istanbul University. The sperm TR and iHsp 70 expression levels were determined using Western blot analysis. The TR activity of the sperm was assayed spectrophometrically. The sperm quality was evaluated both by conventional sperm analysis and by a terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) technique that assayed DNA-fragmented spermatozoa in semen samples. The percentage of TUNEL-positive spermatozoa in the VAR group (16.3%± 5.6%) was higher than that in the fertile group (5.5%± 1.9%). Significant inverse correlations were detected between the percentage of TUNEL-positive cells and both the concentration (r=-0.609; P=0.001) and motility (r=-0.550; P=0.004) of spermatozoa. Both the TR expression and activity were increased significantly in the VAR group (U=22.0; P=0.001 and U=33.5; P=0.012, respectively) as analyzed using the Mann-Whitney U Wilcoxon rank sum W test. Furthermore, significant positive correlations were found between TR expression and activity (r=0.406; P=0.040) and between TR expression and the percentage of TUNEL-positive cells (r=0.665; P=0.001). Sperm iHsp70 expression did not differ between the VAR and fertile groups. In conclusion, increased sperm TR expression might be a defense mechanism against apoptosis in the spermatozoa of men with VAR.

Insight into oxidative stress in varicocele-associated male infertility: part 2

Varicocele, the leading cause of male infertility, can impair spermatogenesis through several pathophysiological mechanisms. Of these, current evidence suggests that oxidative stress is the central element contributing to infertility in men with varicocele, to which the testis responds by way of heat stress, ischaemia or production of vasodilators, such as nitric oxide. Surgical varicocele repair (varicocelectomy) is beneficial not only for alleviating oxidative stress-associated infertility, but also for preventing and protecting against the progressive character of varicocele and its consequent upregulations of systemic oxidative stress. However, antioxidant therapy in infertile men with surgically treated and those with untreated varicocele is poorly studied, and well-designed trials are needed.