Systematic review of antioxidant types and doses in male infertility: Benefits on semen parameters, advanced sperm function, assisted reproduction and live-birth rate

Immunonutrients involved in the regulation of the inflammatory and oxidative processes: implication for gamete competence

Purpose

The purpose of this umbrella review is to bring together the most recent reviews concerning the role of immunonutrients for male and female infertility.

Methods

Regarding immunonutrients and fertility, the authors have analyzed reviews, systematic reviews, and meta-analyses published between 2011 and June 2021. All reviews on animal or in vitro studies were excluded. Relevant keywords to term micronutrients were analyzed alone or in association with other terms such as “gamete competence,” “male OR female fertility,” “male OR female infertility,” “fertile, “folliculogenesis,” “spermatogenesis,” “immunomodulation,” “immune system,” “oxidative stress.”

Results

The primary research has included 108 results, and after screening by title, abstract. and not topic-related, 41 studies have been included by full texts. The results show the molecular mechanisms and the immunonutrients related impact on gamete formation, development. and competence. In particular, this review focused on arginine, glutamine, vitamin C, vitamin D, vitamin E, omega-3, selenium, and zinc.

Conclusions

Inflammation and oxidative stress significantly impact human reproduction. For this reason, immunonutrients may play an important role in the treatment of infertile patients. However, due to the lack of consistent clinical trials, their application is limited. Therefore, the development of clinical trials is necessary to define the correct supplementation, in case of deficiency.

Single injection of very mild dose botulinum toxin in the vastus lateralis improves testicular spermatogenesis and sperm motility in ageing experimental mice

Background

Botulinum toxin (BoNT) is a widely used therapeutic agent that blocks the excessive release of acetylcholine at the neuromuscular junction. Previously, repeated intracremasteric injections and slight overdose of BoNT have been reported to induce adverse effects in the testicular parameter of experimental rodents. However, a mild dose of BoNT is highly beneficial against skin ageing, neuromuscular deficits, overactive urinary bladder problems, testicular pain and erectile dysfunctions. Considering the facts, the possible therapeutic benefits of BoNT on the testis might be achieved at a very minimal dosage and via a distal route of action. Therefore, we revisited the effect of BoNT, but with a trace amount injected into the vastus lateralis of the thigh muscle, and analyzed histological parameters of the testis, levels of key antioxidants and sperm parameters in ageing experimental mice.

Results

Experimental animals injected with 1 U/kg bodyweight of BoNT showed enhanced spermatogenesis in association with increased activities of key antioxidants in the testis, leading to enhanced amount of the total sperm count and progressive motility.

Conclusions

This study signifies that a mild intramuscular dose of BoNT can be considered as a potent treatment strategy to manage and prevent male infertility.

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.

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.

Measuring Reactive Oxygen Species in Semen for Male Preconception Care: A Scientist Perspective

Oxidative stress and elevated levels of seminal and sperm reactive oxygen species (ROS) may contribute to up to 80% of male infertility diagnosis, with sperm ROS concentrations at fertilization important in the development of a healthy fetus and child. The evaluation of ROS in semen seems promising as a potential diagnostic tool for male infertility and male preconception care with a number of clinically available tests on the market (MiOXSYS, luminol chemiluminescence and OxiSperm). While some of these tests show promise for clinical use, discrepancies in documented decision limits and lack of cohort studies/clinical trials assessing their benefits on fertilization rates, embryo development, pregnancy and live birth rates limit their current clinical utility. In this review, we provide an update on the current techniques used for analyzing semen ROS concentrations clinically, the potential to use of ROS research tools for improving clinical ROS detection in sperm and describe why we believe we are likely still a long way away before semen ROS concentrations might become a mainstream preconception diagnostic test in men.

The Impact of Oxidative Stress in Male Infertility

At present infertility is affecting about 15% of couples and male factor is responsible for almost 50% of infertility cases. Oxidative stress, due to enhanced Reactive Oxygen Species (ROS) production and/or decreased antioxidants, has been repeatedly suggested as a new emerging causative factor of this condition. However, the central roles exerted by ROS in sperm physiology cannot be neglected. On these bases, the present review is focused on illustrating both the role of ROS in male infertility and their main sources of production. Oxidative stress assessment, the clinical use of redox biomarkers and the treatment of oxidative stress-related male infertility are also discussed.

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.

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.

Toxicity of Antioxidant Supplements in Patients with Male Factor Infertility: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Treating oxidative stress through antioxidant therapy has been considered an appealing strategy in the management of male infertility. However, evidence regarding the toxicity of antioxidant therapy is controversial. We summarized the available clinical evidence on the toxicity associated with the use of antioxidants in infertile males. A systematic review was performed in March 2021. We included randomized controlled trials evaluating the incidence of adverse events in male patients with infertility receiving antioxidant therapy. Thirteen studies involving 1999 male patients were identified. Antioxidant supplementation in patients with male factor infertility was associated with a statistically significantly increased risk of nausea (Odds Ratio: 2.16, 95% Confidence Interval: 1.05–4.43, p = 0.036), headache (Odds Ratio: 3.05, 95% Confidence Interval: 1.59– 5.85 p = 0.001), and dyspepsia (Odds Ratio: 4.12, 95% Confidence Interval: 1.43–11.85, p = 0.009) compared to a placebo. Treatment discontinuation due to adverse events was not significantly higher in patients taking antioxidants compared to a placebo (Odds Ratio: 2.29, 95% Confidence Interval: 0.76–6.88, p = 0.139). When antioxidant supplementation is considered, a more accurate risk/benefit analysis is warranted.

Structural analysis of Panax ginseng glycoproteins and its anti-oligoasthenozoospermia effect in vivo

A component from ginseng in which sugars and proteins are covalently bound is named Panax ginseng glycoproteins (PGG). The contents of neutral carbohydrate, acid carbohydrate, and protein were 45.4%, 4.3% and 51.1%. The average molecular weight was 12,690 Da. The structure analysis showed that PGG had more than 1100 glycoproteins with molecular weight between 308.13 Da and 9991.52 Da, it was divided into two parts: long chain structure and short chain structure. These two parts were compared in molecular mass, number of amino acids, theoretical pI, instability index, aliphatic index and GRAVY. The in vivo distribution test of mice showed that PGG was enriched in mice testis, testicular tissue sections showed strong fluorescence signal expression on the surface of seminiferous tubules. We used cyclophosphamide (CP) to establish a mice model of oligoasthenozoospermia to investigate the anti-oligoasthenozoospermic effect of PGG. The results showed that PGG increased the levels of sex hormones T, FSH, PRL and sperm quality. Histopathology demonstrated that PGG promoted the differentiation process. The organ coefficient indicated that PGG had no obvious toxic and side effects. And the mechanism may be to affect the expression of protein levels such as p-ERK/ERK, p-AKT/AKT, Caspase-3, Bcl-2 and Bax. Therefore, PGG has the potential to develop into drugs for improving spermatogenic disorders.

Antioxidants in male infertility

OBJECTIVE

To study the effect of three antioxidants viz. selenium, carnitine and coenzyme Q10, alone or in combination, on both semen parameters and pregnancy rates in couples with male factor infertility.

METHODS

Using PRISMA guidelines, a systematic search was performed of the PubMed®, Scopus®, EMBASE®, and Web of Science® databases for randomized studies comparing selenium, carnitine or coenzyme Q10 with placebo in the treatment of male infertility and reporting semen and pregnancy outcomes.

RESULTS

3304 studies were screened of which 20 were included. The study protocol was registered with PROSPERO (CRD42020210284). Pregnancy rate in the treatment group (69/426, 16.2%) was not different from the placebo (45/401, 11.2%) (p=0.05). Treatment group showed higher motility [mean difference 5.05, 95% CI (2.77, 7.34), p=<0.0001], progressive motility [mean difference 5.72, 95% CI (2.77, 8.66), p=0.0001], sperm concentration [mean difference 6.58, 95% CI (3.22, 9.93), p=0.0001] than placebo.

CONCLUSIONS

Although antioxidants and their combinations are associated with improvement in sperm concentration, motility, and semen volume, the differences are small. There is no difference in pregnancy rates between patients receiving selenium, carnitine, and coenzyme Q10, or placebo. The quality of studies is poor, limiting the level of evidence.

A 150 kDa Protein Derived from Bull Seminal Plasma Extended the Survival Time of Kacang Goat Sperm Stored at 5°C

Artificial insemination has proven to be an effective method for increasing population size and genetic quality of Kacang goats. However, innovation is required to maintain the quality of Kacang goat semen in storage. This study aimed to examine the effects of supplementing the 150 kDa protein assumed as IGF-I complex derived from bull seminal plasma in skim milk-egg yolk extender on the quality of Kacang goat sperm stored at 5°C. Twelve ejaculates collected from three Kacang goats were divided into three groups. In the control group (T0), the ejaculates were extended with skim milk-egg yolk only. In the treatment groups (T1 and T2), the ejaculates were extended with skim milk-egg yolk supplemented with the IGF-I complex protein at 12 μg and 24 μg/100 mL, respectively. The extended semen was stored at 5°C, and the viability, motility, intactness of the plasma membrane, malondialdehyde concentration, and apoptotic sperm percentage were evaluated daily for five days. The results showed that the T1 was the most effective treatment for maintaining Kacang goat semen at a quality acceptable for artificial insemination over five days of storage at 5°C. However, the T0 and T2 groups retained acceptable qualities for only three days at 5°C. It could be concluded that supplementation of 12 μg of the 150 kDa protein derived from bull seminal plasma per 100 mL extender successfully extended the life span of Kacang goat sperm for five days.

The Role of the Natural Antioxidant Mechanism in Sperm Cells

Molecular studies of the causes of male infertility revealed a significant contribution of oxidative stress. When excessive amounts of reactive oxygen species (ROS) are produced or antioxidant activity fails, the equilibrium between oxidation and reduction is disrupted, causing oxidative stress (OS). High levels of ROS can have an adverse effect on sperm function through the initiation of DNA damage, lipid peroxidation, loss of membrane integrity and increased permeability, inactivation of cellular enzymes, and cell apoptosis. In addition to endogenous factors such as immature sperm, leukocytes, and varicocele, potential causes of excessive ROS can also be found exogenously in males with testicular hyperthermia or exposed to environmental toxicity. To maintain the optimal functioning of sperm cells, it is, therefore, necessary to balance the redox potential, i.e., to balance ROS by antioxidants. The purpose of this review is to present the antioxidant defense systems in semen.

The Effect of Oral Vitamin E on Semen Parameters and IVF Outcome: A Double-Blinded Randomized Placebo-Controlled Clinical Trial

Background

Male infertility is a main clinical problem that affects about 7% of all men worldwide. Many patients with male infertility are caused by a reduced antioxidant capacity of semen. Several antioxidant supplements, especially vitamin E, are proposed to help male infertility treatment. This project was goaled to study the effects of oral synthetic vitamin E (400 IU/day) for eight weeks on betterment of semen parameters and pregnancy rate.

Methods

After dropping the cases, 124 infertile couples with a male factor who were admitted to the IVF program were included. The male patients with idiopathic abnormal motility and/or morphology were randomized into two groups: 61 receiving vitamin E and 63 as the control group receiving placebo for eight weeks. The pretreatment semen parameters of both groups were compared with those of posttreatment. The pregnancy outcomes were considered between the two groups.

Results

There were no significant differences statistically between before and after treatment in the term of sperm volume, count, motility, and morphology. Furthermore, the IVF outcomes of the two groups were not different significantly, either. Interestingly, the percent of normal sperm in the placebo group was significantly decreased after eight weeks.

Conclusion

Vitamin E supplementation might neutralize free radical activity to keep sperm from more oxidative damages. Further studies regarding the influence of higher acceptable doses of vitamin E on semen characteristics and fertility rates are needed. This study was registered as a two-arm, blinded, randomized, placebo-controlled clinical trial (IRCTID: IRCT2014020616506N1, 2014-03-18).

Effect of insulin-like growth factor-1 complex of Simmental bull seminal plasma on post-thawed Kacang buck semen fertility

Background and Aim

Kacang buck sperm is cryosensitive due to the seminal plasma of semen itself. Meanwhile, bull seminal plasma contains the insulin-like growth factor-1 (IGF-1) complex, which is cryoprotective. The addition of the crude protein of Simmental bull seminal plasma increased the quality of post-thawed semen of Kacang buck. The study was conducted to determine the effects of Simmental bull seminal plasma with IGF-1 on the fertility of post-thawed Kacang buck semen.

Materials and Methods

Buck semen was diluted in the following skim milk-egg yolk extender preparations: Without the addition of Simmental bull seminal plasma IGF-1 complex protein (T0); with the addition of 12-μg Simmental bull seminal plasma IGF-1 complex protein (T1); and with the addition of 24-μg Simmental bull seminal plasma IGF-1 complex protein (T2). The extended semen was packed in 0.25-mL straws and frozen. Post-thawed semen fertility was evaluated based on the following variables: Sperm motility, viability, intact plasma membrane (IPM), malondialdehyde (MDA) levels, capacitation status, and acrosome reaction. The difference in each variable among the groups was evaluated using analysis of variance, followed by Tukey's honestly significant difference test, at a 95% level of significance. Meanwhile, principal component analysis (PCA) was used to identify the principal component of semen fertility among the seven parameters.

Results

The T1 group showed the highest sperm motility, viability, IPM, and percentage of incapacitated sperm and the lowest MDA levels, percentage of capacitated sperm, and acrosome reaction. PCA revealed that sperm motility had a moderate to very robust correlation with other variables and is the most crucial parameter, accounting for 80.79% of all variables.

Conclusion

The IGF-1 complex in Simmental bull seminal plasma was useful for increasing the fertility of post-thawed Kacang buck semen, and sperm motility was the principal component of semen fertility.

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.

Infertility cell therapy and epigenetic insights

Recent advances in assisted reproductive technology (ART) have allowed couples with severe infertility to conceive, but the methods are not effective for all cases. Stem cells as undifferentiated cells which are found in different stages of embryonic, fetal and adult life are known to be capable of forming different cell types, tissues, and organs. Due to their unlimited resources and the incredible power of differentiation are considered as potential new therapeutic biological tools for treatment of infertility. For reproductive medicine, stem cells are stimulated in vitro to develop various specialized functional cells including male and female gametes. The epigenetic patterns can be modified in the genome under certain drugs exposure or lifestyle alterations. Therefore, epigenetics-related disorders may be treated if the nature of the modifications is completely admissible. It is proved that our understanding of epigenetic processes and its association with infertility would help us not only to understand the etiological factors but also to treat some type of male infertilities. Exploration of both genetic and epigenetic variations in the disease development could help in the identification of the interaction patterns between these two phenomena and possible improvement of therapeutic methods.

Oral Antioxidant Treatment of Men Significantly Improves the Reproductive Outcome of IVF Cycles

Some 30% to 80% of male sub-fertility may be associated with oxidative stress that damages spermatozoa and can decrease success of in vitro fertilization (IVF) techniques. This multicenter, longitudinal, prospective study aimed to investigate whether oral antioxidant supplementation improved the reproductive competence of men who had had low fertilization rates in their previous intracytoplasmic sperm injection (ICSI) cycles without azoospermia or severe oligozoospermia or any identifiable andrological disease. Seventy-seven men from couples who had an ICSI attempt with unexplained <60% fertilization rate took an antioxidant mix of myo-inositol, alpha-lipoic acid, folic acid, coenzyme Q10, zinc, selenium, and vitamins B2, B6, and B12. Semen parameters were analyzed before (T0) and after 90 days (T90) of treatment, and outcomes of the paired T0 and T90 cycles were compared. After the treatment there was an increase in sperm concentration (p = 0.027), total motile sperm count (p = 0.003), progressive motility (p < 0.0001), and a decreasing trend of DNA-fragmented spermatozoa. Embryological outcomes (fertilization, embryo quality, blastocyst development) were significantly higher in T90 than T0 cycles. No T0 cycle resulted in an evolutive pregnancy. Conversely, in T90 cycles 29 singleton clinical pregnancies were obtained. No negative neonatal outcomes were recorded in newborns after antioxidant treatment. Diet supplementation of men who have had low fertilization rates in their previous ICSI cycles with a combination of myo-inositol, alpha-lipoic acid, folic acid, coenzyme Q10, zinc, selenium, betaine, and vitamins may improve semen reproductive potential and ICSI clinical outcome.

Oral Antioxidant Treatment of Men Significantly Improves the Reproductive Outcome of IVF Cycles

Some 30% to 80% of male sub-fertility may be associated with oxidative stress that damages spermatozoa and can decrease success of in vitro fertilization (IVF) techniques. This multicenter, longitudinal, prospective study aimed to investigate whether oral antioxidant supplementation improved the reproductive competence of men who had had low fertilization rates in their previous intracytoplasmic sperm injection (ICSI) cycles without azoospermia or severe oligozoospermia or any identifiable andrological disease. Seventy-seven men from couples who had an ICSI attempt with unexplained <60% fertilization rate took an antioxidant mix of myo-inositol, alpha-lipoic acid, folic acid, coenzyme Q10, zinc, selenium, and vitamins B2, B6, and B12. Semen parameters were analyzed before (T0) and after 90 days (T90) of treatment, and outcomes of the paired T0 and T90 cycles were compared. After the treatment there was an increase in sperm concentration (p = 0.027), total motile sperm count (p = 0.003), progressive motility (p < 0.0001), and a decreasing trend of DNA-fragmented spermatozoa. Embryological outcomes (fertilization, embryo quality, blastocyst development) were significantly higher in T90 than T0 cycles. No T0 cycle resulted in an evolutive pregnancy. Conversely, in T90 cycles 29 singleton clinical pregnancies were obtained. No negative neonatal outcomes were recorded in newborns after antioxidant treatment. Diet supplementation of men who have had low fertilization rates in their previous ICSI cycles with a combination of myo-inositol, alpha-lipoic acid, folic acid, coenzyme Q10, zinc, selenium, betaine, and vitamins may improve semen reproductive potential and ICSI clinical outcome.

Impacts of Immunometabolism on Male Reproduction

The physiological process of male reproduction relies on the orchestration of neuroendocrine, immune, and energy metabolism. Spermatogenesis is controlled by the hypothalamic-pituitary-testicular (HPT) axis, which modulates the production of gonadal steroid hormones in the testes. The immune cells and cytokines in testes provide a protective microenvironment for the development and maturation of germ cells. The metabolic cellular responses and processes in testes provide energy production and biosynthetic precursors to regulate germ cell development and control testicular immunity and inflammation. The metabolism of immune cells is crucial for both inflammatory and anti-inflammatory responses, which supposes to affect the spermatogenesis in testes. In this review, the role of immunometabolism in male reproduction will be highlighted. Obesity, metabolic dysfunction, such as type 2 diabetes mellitus, are well documented to impact male fertility; thus, their impacts on the immune cells distributed in testes will also be discussed. Finally, the potential significance of the medicine targeting the specific metabolic intermediates or immune metabolism checkpoints to improve male reproduction will also be reassessed.

Nutritional supplementation of the pharmacotherapy of prostate diseases

Introduction: Nutritional supplementation is an integral part of modern pharmacotherapeutic strategies for prostate diseases with different levels of evidence for specific nutrients.

Provitamin A (beta-carotene), vitamin A (retinol) and prostate diseases. Their effects have not been sufficiently studied, and the available data are conflicting to recommend them as a nutritional supplement.

Vitamin E (tocopherol) and prostate diseases. Its effects have not been sufficiently studied, and the available data are conflicting to recommend it as a nutritional supplement.

Vitamin C (ascorbic acid) and prostate diseases. Its effects have not been sufficiently studied, and the available data are conflicted to recommend it as a nutritional supplement.

Vitamin K and prostate diseases. Its effects have not been sufficiently studied, and the available data are conflicted to recommend it as a nutritional supplement.

Vitamin D and prostate diseases. The evidence base of the vitamin D prostatotropic effects has been accumulated, which allows us to consider its deficiency replacement as an effective nutritional supplement in prostate diseases.

Omega-3 PUFAs and prostate diseases. They have universal physiological effects; however, the evidence base for their recommendation as a nutritional supplement for prostate diseases is still insufficient.

Zinc and prostate diseases. Positive effects of zinc on the prostate gland are known for a fact and allow us to recommend it as a nutritional supplement for prostate diseases.

Selenium and prostate diseases. The reliably proven positive effects of selenium on the prostate gland allow us to recommend it as a nutritional supplement for prostate diseases.

Magnesium and prostate diseases. Its effects have not been sufficiently studied, and the available data are conflicting to recommend it as a nutritional supplement.

Can Nutrition Help in the Treatment of Infertility?

Infertility is defined as the inability to conceive after 12 months of unprotected intercourse or six months for women aged 35 years or older. The physical, emotional, psychological, and financial statuses of infertile couples are tremendously affected especially after undergoing diagnostic and/or curative treatments. Human fertility is influenced by multiple factors including female or male, and modifiable or non-modifiable factors. There is growing evidence that nutri-tion may play an important role in adjusting fertility-related outcomes in both men and women. The objective of our study was to summarize the latest data on nutritional factors (specific food groups, nutrients, and nutritional supplements) that have an impact on female or male sexual and reproductive function. PubMed and Google Scholar platforms were used to collect appropriate articles for the review using several combinations of keywords (infertility, diet, dietary supplements, antioxidants, and beverages). Adherence to a healthy dietary pattern favoring fish, poultry, whole grains, fruits, vegetables, and healthy fats, was related to better fertility in both genders. Despite the multifactorial etiology of sexual infertility, nutrition may affect the sexual/reproductive function in both women and men.

Coenzyme Q10, oxidative stress markers, and sperm DNA damage in men with idiopathic oligoasthenoteratospermia

Objective

Oxidative stress (OS) plays a key role in the etiology of unexplained male infertility. Coenzyme Q10 (CoQ10) is a potent antioxidant that may improve semen quality and OS in infertile men with idiopathic oligoasthenoteratospermia (OAT), but the underlying mechanism is unknown. Therefore, the present study was undertaken to investigate the effect of CoQ10 on OS markers and sperm DNA damage in infertile patients with idiopathic OAT.

Methods

This prospective controlled study included 50 patients with idiopathic OAT and 50 fertile men who served as controls. All patients underwent a comprehensive medical assessment. Patients and controls received 200 mg of oral CoQ10 once daily for 3 months. Semen and blood were collected and analyzed for sperm parameters, seminal CoQ10 levels, reactive oxygen species (ROS) levels, total antioxidant capacity, catalase, sperm DNA fragmentation (SDF), and serum hormonal profile.

Results

The administration of CoQ10 to patients with idiopathic OAT significantly improved sperm quality and seminal antioxidant status and significantly reduced total ROS and SDF levels compared to pretreatment values.

Conclusion

CoQ10, at a dose of 200 mg/day for 3 months, may be a potential therapy for infertile patients with idiopathic OAT, as it improved sperm parameters and reduced OS and SDF in these patients.

Protective effect of vitamin E on sperm parameters, chromatin quality, and DNA fragmentation in mice treated with different doses of ethanol: An experimental study

BACKGROUND

Excessive consumption of alcohol induces an increase in oxidative stress production and can lead to detrimental effects on the male reproductive system.

OBJECTIVE

To evaluate the possible protective effects of coadministration of vitamin (vit) E on the detrimental changes in the sperm quality of mice administered ethanol.

MATERIALS AND METHODS

Fifty-four BALB/c mice were categorized into nine groups (n = 6/each). The control group received a basal diet while the eight experimental groups received ethanol 10%; ethanol 20%; vit. E 100 mg; vit. E 200 mg; ethanol 10% + vit. E 100 mg; ethanol 10% + vit. E 200 mg; ethanol 20% + vit. E 100 mg; ethanol 20% + vit. E 200 mg. After 35 days, the sperm parameters and sperm chromatin were assessed.

RESULTS

The results demonstrated a significant reduction in the motility rate, normal morphology rate, viability rate, increase in abnormal DNA structure and packaging (TB staining), and DNA damage (TUNEL) in ethanol consumer groups. In addition, the findings showed a significant increase in the aforementioned parameters in ethanol- and vit. E-consumer groups compared to the ethanol-only consumer groups. The ethanol group received 20% of the most damage among the groups. The group receiving vit. E 100 mg and those receiving ethanol 10% + vit. E 200 mg gained the highest benefit among the groups.

CONCLUSION

Sperm forward progressive motility, normal morphology rate, and viability decreased in the ethanol groups. Also, the rates of spermatozoa with abnormal DNA structure and DNA fragmentation increased in the ethanol groups. Our findings revealed that the coadministration of vit. E and ethanol can protect destructive changes in DNA structure and damage.

Low-fat diets and testosterone in men: Systematic review and meta-analysis of intervention studies

BACKGROUND

Higher endogenous testosterone levels are associated with reduced chronic disease risk and mortality. Since the mid-20th century, there have been significant changes in dietary patterns, and men's testosterone levels have declined in western countries. Cross-sectional studies show inconsistent associations between fat intake and testosterone in men.

METHODS

Studies eligible for inclusion were intervention studies, with minimal confounding variables, comparing the effect of low-fat vs high-fat diets on men's sex hormones. 9 databases were searched from their inception to October 2020, yielding 6 eligible studies, with a total of 206 participants. Random effects meta-analyses were performed using Cochrane's Review Manager software. Cochrane's risk of bias tool was used for quality assessment.

RESULTS

There were significant decreases in sex hormones on low-fat vs high-fat diets. Standardised mean differences with 95 % confidence intervals (CI) for outcomes were: total testosterone [-0.38 (95 % CI -0.75 to -0.01) P = 0.04]; free testosterone [-0.37 (95 % CI -0.63 to -0.11) P = 0.005]; urinary testosterone [-0.38 (CI 95 % -0.66 to -0.09) P = 0.009]; and dihydrotestosterone [-0.3 (CI 95 % -0.56 to -0.03) P = 0.03]. There were no significant differences for luteinising hormone or sex hormone binding globulin. Subgroup analysis for total testosterone, European and North American men, showed a stronger effect [-0.52 (95 % CI -0.75 to -0.3) P < 0.001].

CONCLUSIONS

Low-fat diets appear to decrease testosterone levels in men, but further randomised controlled trials are needed to confirm this effect. Men with European ancestry may experience a greater decrease in testosterone, in response to a low-fat diet.

High-Dose Supplementation of Folic Acid in Infertile Men Improves IVF-ICSI Outcomes: A Randomized Controlled Trial (FOLFIV Trial)

Dietary supplementation is commonly used in men with male infertility but its exact role is poorly understood. The aim of this multicenter, randomized, double-blind, placebo-controlled trial was to evaluate the impact of high-dose folic acid supplementation on IVF-ICSI outcomes. 162 couples with male infertility and an indication for IVF-ICSI were included for one IVF-ICSI cycle. Male partners of couples wishing to conceive, aged 18-60 years old, with at least one abnormal spermatic criterion were randomized in a 1:1 ratio to receive daily supplements containing 15 mg of folic acid or a placebo for 3 months from Day 0 until semen collection for IVF-ICSI. Sperm parameters and DNA fragmentation before and after the treatment and the biochemical and clinical pregnancy rates after the fresh embryo transfer were analyzed. We observed an increase in the biochemical pregnancy rate and a trend for a higher clinical pregnancy rate in the folic acid group compared to placebo (44.1% versus 22.4%, p = 0.01 and 35.6% versus 20.4%, p = 0.082, respectively). Even if no changes in sperm characteristics were observed, a decrease in DNA fragmentation in the folic acid group was noted (8.5 ± 4.5 vs. 6.4 ± 4.6, p < 0.0001). High-dose folic acid supplementation in men requiring IVF-ICSI for male infertility improves IVF-ICSI outcomes.

Advancing Semen Evaluation Using Lipidomics

Developing a deeper understanding of biological components of sperm is essential to improving cryopreservation techniques and reproductive technologies. To fully ascertain the functional determinants of fertility, lipidomic methods have come to the forefront. Lipidomics is the study of the lipid profile (lipidome) within a cell, tissue, or organism and provides a quantitative analysis of the lipid content in that sample. Sperm cells are composed of various lipids, each with their unique contribution to the overall function of the cell. Lipidomics has already been used to find new and exciting information regarding the fatty acid content of sperm cells from different species. While the applications of lipidomics are rapidly evolving, gaps in the knowledge base remain unresolved. Current limitations of lipidomics studies include the number of available samples to analyze and the total amount of cells within those samples needed to detect changes in the lipid profiles across different subjects. The information obtained through lipidomics research is essential to systems and cellular biology. This review provides a concise analysis of the most recent developments in lipidomic research. This scientific resource is important because these developments can be used to not only combat the reproductive challenges faced when using cryopreserved semen and artificial reproductive technologies in livestock such as cattle, but also other mammals, such as humans or endangered species.

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.

Impact of Coenzyme Q10 and Selenium on Seminal Fluid Parameters and Antioxidant Status in Men with Idiopathic Infertility

Oxidative stress (OS) is a key contributing factor in 30-80% of male infertility cases. To date, several antioxidant treatments have been put forth to manage OS-induced male infertility. This study intended to elucidate the impact of coenzyme Q10 (CoQ10) and selenium on seminal fluid parameters and antioxidant status in infertile men with idiopathic oligoasthenoteratospermia (OAT). In this prospective study, 70 patients with idiopathic OAT were randomly allocated to receive CoQ10 (200 mg/day) or selenium (200 μg/day) for 3 months. Semen quality parameters (following WHO guidelines, 5th edition), total antioxidant capacity (TAC), catalase (CAT), and superoxide dismutase (SOD) activities were compared before and after the treatment. The results of the study showed an increase in sperm concentration with CoQ10 treatment (p < 0.01) as well as increased progressive sperm motility (p < 0.01 and p < 0.05) and total sperm motility (p < 0.01 and p < 0.05) with CoQ10 and selenium treatment respectively. There was also a significant improvement in TAC (p < 0.01 and p < 0.05) and SOD (p < 0.01 and p < 0.05) following treatment with CoQ10 and selenium respectively while CAT improved only with CoQ10 therapy (p < 0.05). Sperm concentration, motility, and morphology also correlated significantly with TAC, SOD, and CAT (r = 0.37-0.76). In conclusion, treatment with CoQ10 (200 mg) or selenium (200 μg) could improve sperm concentration, motility, and antioxidant status in infertile men with idiopathic OAT with CoQ10 providing the higher improvement.

Dietary Antioxidants in the Treatment of Male Infertility: Counteracting Oxidative Stress

Infertility affects about 15% of the population and male factors only are responsible for ~25-30% of cases of infertility. Currently, the etiology of suboptimal semen quality is poorly understood, and many environmental and genetic factors, including oxidative stress, have been implicated. Oxidative stress is an imbalance between the production of free radicals, or reactive oxygen species (ROS), and the capacity of the body to counteract their harmful effects through neutralization by antioxidants. The purpose of this review, by employing the joint expertise of international researchers specialized in nutrition and male fertility areas, is to update the knowledge about the reproductive consequences of excessive ROS concentrations and oxidative stress on the semen quality and Assisted Reproduction Techniques (ART) clinical outcomes, to discuss the role of antioxidants in fertility outcomes, and finally to discuss why foods and dietary patterns are more innocuous long term solution for ameliorating oxidative stress and therefore semen quality results and ART fertility outcomes. Since this is a narrative review and not a systematic/meta-analysis, the summarized information in the present study should be considered cautiously.

Green tea extract increases the quality and reduced DNA mutation of post-thawed Kacang buck sperm

The study aimed to determine the addition of green tea extract (GTE) in extender on the quality and DNA mutation of post-thawed Kacang buck sperm. The sperm DNA mutation was observed on nicotinamide adenine dinucleotide hydride (NADH) dehydrogenase 1 (ND1) of mitochondrial Deoxyribonucleic Acid (mtDNA). A pool of 12 Kacang buck ejaculates was diluted in skim milk-egg yolk extender contained 0, 0.05, 0.10, and 0.15 mg of GTE/100 mL for T0, T1, T2, and T3 group, respectively. Each of the aliquot groups was packaged in 0.25 mL French mini straw contained 60 million alive sperm and froze according to the protocol. The ND1 mtDNA amplification of samples was carried out Polymerase Chain Reaction machine, followed by DNA sequencing using the Sanger method. Meanwhile, the phylogenetic tree was constructed using the neighbor-joining (NJ) method with MEGA 7.0 software. The results showed that the T2 group maintained the highest quality for Kacang buck post-thawed semen. There was the highest percentages of sperms viability, motility, intact plasma membrane (IPM), the lowest of malondialdehyde (MDA) concentration, sperm DNA fragmentation (SDF), the total and types of ND1 mtDNA mutation frequency. The phylogenetic tree analysis revealed that the clade of the T2 group was most closely related to the sequence reference. However, there was no correlation between the semen quality parameters (sperm viability, motility, IPM, MDA concentration, and SDF) with ND1 mtDNA mutation of post-thawed Kacang buck semen. It could be concluded that GTE was useful as an antioxidant for Kacang buck semen extender for frozen sperm.

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.

Mitochondria: their role in spermatozoa and in male infertility

BACKGROUND

The best-known role of spermatozoa is to fertilize the oocyte and to transmit the paternal genome to offspring. These highly specialized cells have a unique structure consisting of all the elements absolutely necessary to each stage of fertilization and to embryonic development. Mature spermatozoa are made up of a head with the nucleus, a neck, and a flagellum that allows motility and that contains a midpiece with a mitochondrial helix. Mitochondria are central to cellular energy production but they also have various other functions. Although mitochondria are recognized as essential to spermatozoa, their exact pathophysiological role and their functioning are complex. Available literature relative to mitochondria in spermatozoa is dense and contradictory in some cases. Furthermore, mitochondria are only indirectly involved in cytoplasmic heredity as their DNA, the paternal mitochondrial DNA, is not transmitted to descendants.

OBJECTIVE AND RATIONAL

This review aims to summarize available literature on mitochondria in spermatozoa, and, in particular, that with respect to humans, with the perspective of better understanding the anomalies that could be implicated in male infertility.

SEARCH METHODS

PubMed was used to search the MEDLINE database for peer-reviewed original articles and reviews pertaining to human spermatozoa and mitochondria. Searches were performed using keywords belonging to three groups: 'mitochondria' or 'mitochondrial DNA', 'spermatozoa' or 'sperm' and 'reactive oxygen species' or 'calcium' or 'apoptosis' or signaling pathways'. These keywords were combined with other relevant search phrases. References from these articles were used to obtain additional articles.

OUTCOMES

Mitochondria are central to the metabolism of spermatozoa and they are implicated in energy production, redox equilibrium and calcium regulation, as well as apoptotic pathways, all of which are necessary for flagellar motility, capacitation, acrosome reaction and gametic fusion. In numerous cases, alterations in one of the aforementioned functions could be linked to a decline in sperm quality and/or infertility. The link between the mitochondrial genome and the quality of spermatozoa appears to be more complex. Although the quantity of mtDNA, and the existence of large-scale deletions therein, are inversely correlated to sperm quality, the effects of mutations seem to be heterogeneous and particularly related to their pathogenicity.

WIDER IMPLICATIONS

The importance of the role of mitochondria in reproduction, and particularly in gamete quality, has recently emerged following numerous publications. Better understanding of male infertility is of great interest in the current context where a significant decline in sperm quality has been observed.

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.

The effect of folate on ischemia/reperfusion injury in a rat adnexal torsion model

PURPOSE

The ischemia/reperfusion (I/R) injury of ovaries in adnexal torsion may have inadvertent consequences. Many agents have been studied in terms of their ability to prevent reperfusion damage to ovaries in suspected cases. In this study, folic acid, known to have antioxidative properties, was investigated to determine whether it played a role in the prevention of I/R damage in a rat ovarian torsion model.

METHODS

In this experimental study, 40 female adult Wistar-Albino rats were randomly divided into five groups as control, ischemia, I/R, Fol2 (2 mg/kg folic acid), and Fol4 (4 mg/kg folic acid). In the Fol2 and Fol4 groups, folic acid was intraperitonelly administered 30 min before reperfusion. Blood samples were obtained from the tails of each rat at the second hour of reperfusion.

RESULTS

The total oxidant status (TOS), total antioxidant status, cystatin C and folic acid levels of the five groups were investigated. Folic acid in 2 mg/kg dose could moderately increase the serum folic acid concentration (15.75-19.95 ng/ml, p < 0.05), reduce the level of cystatin C (0.18-0.12 μg/L, p < 0.05), and had a tendency to improve the oxidative stress injury (OSI: 76.05-33.06, p > 0.05), although there was no statistical difference in TOS levels (p = 0.07). Folic acid in 4 mg/kg dose, could significantly increase the serum folic acid concentration (15.75-37.65 ng/ml). However, it did not significantly reduce the level of cystatin C (0.18-0.19 μg/L, p > 0.05), and did not improve oxidative stress injury (76.05-130.58, p > 0.05).

CONCLUSION

Folic acid in 2 mg/kg dose might improve the ovarian I/R injury though this was not statistically significant. Further studies are required to reach a definitive conclusion about the protective effect of folic acid in I/R injury.

Mechanistic Insight into the Regulation of Lipoxygenase-Driven Lipid Peroxidation Events in Human Spermatozoa and Their Impact on Male Fertility

A prevalent cause of sperm dysfunction in male infertility patients is the overproduction of reactive oxygen species, an attendant increase in lipid peroxidation and the production of cytotoxic reactive carbonyl species such as 4-hydroxynonenal. Our previous studies have implicated arachidonate 15-lipoxygenase (ALOX15) in the production of 4-hydroxynonenal in developing germ cells. Here, we have aimed to develop a further mechanistic understanding of the lipoxygenase-lipid peroxidation pathway in human spermatozoa. Through pharmacological inhibition studies, we identified a protective role for phospholipase enzymes in the liberation of peroxidised polyunsaturated fatty acids from the human sperm membrane. Our results also revealed that arachidonic acid, linoleic acid and docosahexanoic acid are key polyunsaturated fatty acid substrates for ALOX15. Upon examination of ALOX15 in the spermatozoa of infertile patients compared to their normozoospermic counterparts, we observed significantly elevated levels of ALOX15 protein abundance in the infertile population and an increase in 4-hydroxynonenal adducts. Collectively, these data confirm the involvement of ALOX15 in the oxidative stress cascade of human spermatozoa and support the notion that increased ALOX15 abundance in sperm cells may accentuate membrane lipid peroxidation and cellular dysfunction, ultimately contributing to male infertility.

Recent advances and controversies in diagnosing and treating male infertility

Interest in male infertility has increased, as it plays an important role in up to 50% of couples struggling with infertility, which is an estimated 48.5 million couples globally. Despite recent advances, diagnosing and treating male infertility remain a significant clinical challenge owing to complex multifactorial pathways and the diversity of treatment options. This review will assess current controversial topics on male infertility such as the use of home-based semen testing, management of subclinical varicocele, and recent advances in the field of sperm proteomics.

Antioxidant effects of N-acetylcysteine on the male reproductive system: A systematic review

This study aimed to evaluate the effect of N-acetyl cysteine on the male reproductive system and consensus and classification of data found from previous studies. It is undeniable that N-acetyl cysteine as a powerful antioxidant compound can medicate many diseases such as cardiovascular, kidney, liver and reproductive system disorders. With the increasing environmental pollution that has a direct adverse effect on male fertility, the use of this compound is able to positively function on human fertility health. In this study, we have been collected the main data of scientific articles (1994-2020) about N-acetyl cysteine effects. By searching in the scientific databases of PubMed, Google Scholar, Science Direct, Wiley and Web of Science, related articles were extracted. As a result, all observations have confirmed that N-acetyl cysteine can improve and normalise the spermatogenesis in the male reproduction system.

L-carnitine as primary or adjuvant treatment in infertile patients with varicocele. A systematic review

BACKGROUND

Varicocele has been found to impair the function of the epididymis resulting in subfertility whereas the varicocelectomy can resolve the phenomenon. L-carnitine is regarded as a biomarker for the function of the epididymis and has been found in reduced concentrations in infertile patients of various causes, including infertile men with varicocele. It seems that Lcarnitine and varicocele share clinical significance and the area of research looks promising.

OBJECTIVE

To identify the role of L-carnitine in the treatment of varicocele.

MATERIALS AND METHODS

A systematic search was performed in Pubmed/Medline with the terms (L-carnitine) and (varicocele) and (L-carnitine) and (varicocelectomy). Inclusion criteria were studies reported outcomes of L-carnitine administration alone or in duet, as primary or adjuvant treatment to varicocele. Exclusion criteria were non-English language and animal studies. Studies using L-carnitine as part of a panel of therapeutic agents were avoided.

RESULTS

Only four suitable studies were identified for discussion. In one randomized study, the combination of L-carnitine and cinnoxicam improved semen parameters in patients with non-high-grade varicocele compared to L-carnitine alone and had a favourable effect on pregnancy rates but the effect of grade is unknown. In another study, as an adjuvant treatment to varicocelectomy, L-carnitine showed no clear benefit. Finally, in comparison to surgery, the results are inconclusive; two studies showed some benefit might be expected in low-grade or subclinical varicocele, but surgery appears superior.

CONCLUSIONS

The evidence regarding the role of L-carnitine as a primary or adjuvant treatment of varicocele is sparse. The pathophysiological significance of L-carnitine implicates a potential role of the molecule in the management of varicocele, but the evidence so far is controversial for any recommendations. L-carnitine might be taken into consideration in selected cases; however, further search is needed in order the optimal role of L-carnitine in infertile patients with varicocele to be clarified.

Probiotic effects on sperm parameters, oxidative stress index, inflammatory factors and sex hormones in infertile men

Decreased sperm motility is one of the main causes of male infertility. The aim of this study was to evaluate the effects of probiotic supplementation on semen quality, seminal oxidative stress biomarkers, inflammatory factors and reproductive hormones. In this randomised, double-blind controlled clinical trial, 52 men with idiopathic oligoasthenoteratozoospermia attending a urology clinic, were randomly assigned to either an intervention or placebo (n = 26) group. This investigation was registered by the identification code of IRCT20141025019669N7 in the clinical trials registry of Iran. The Intervention group took 500 mg of Probiotics daily and the placebo group took a daily placebo for 10 weeks. Semen parameters, total antioxidant capacity, malondialdehyde, inflammatory factors and reproductive hormones were measured at baseline and at the end of the study. After the intervention, ejaculate volume, number, concentration and the percentage of motile sperm, total antioxidant capacity of plasma significantly increased and the concentration of plasma malondialdehyde and inflammatory markers significantly decreased in the intervention group. Probiotic supplementation in infertile men lead to a significant increase in sperm concentration and motility and a significant reduction in oxidative stress and inflammatory markers. Therefore, oral intake of probiotics has the potential to be one of the ways to deal with oxidative damage of sperm.

Comparison of the Effect of Ceratonia siliqua L. (Carob) Syrup and Vitamin E on Sperm Parameters, Oxidative Stress Index, and Sex Hormones in Infertile Men: a Randomized Controlled Trial

Herbal products with an antioxidant capacity can boost male reproductive functions. The empiric use of Ceratonia siliqua (carob) for its antioxidant properties is common among infertile men in Iran and Turkey. The objective of this study is to investigate the effects of C. siliqua (carob) on semen parameters, oxidative stress markers, and pregnancy rate in a parallel randomized, controlled study. A total of 60 infertile men with oligozoospermia, asthenospermia, and teratospermia were recruited from April 2018 to March 2019. Participants were divided randomly into the following two groups: carob syrup twice a day or vitamin E 100 mg twice a day for 3 months. Semen analysis was performed and hormonal levels and stress oxidative markers were measured in each treatment arm after 3 months. The quality of semen parameters improved in the carob group compared with Vit E semen count (p = 0.04 Cohen's d = .51), morphology (p = 0.001 Cohen's d = .93) and motility parameters (p = 0.002 Cohen's d = .90) were significantly higher in the carob group. No significant difference can be detected in post-treatment hormonal parameters and oxidative markers between groups, except for total antioxidant capacity(TAC) which was higher after post-treatment in carob group. A significantly higher pregnancy rate was found among the carob group. The administration of carob may be an effective agent for the improvement of semen parameters, probably related both to its involvement in the changing of testosterone level and to its antioxidant properties. Nevertheless, additional studies to evaluate the optimal dose and duration of treatment are needed. The trial has been registered in the Iranian Registry of Clinical Trials (Registration number: IRCT20171209037794N1.

Capsaicin improves sperm quality in rats with experimental varicocele

Capsaicin is the main capsaicinoid in chilli peppers that have numerous biological and pharmaceutical roles in the body such as antioxidant, anti-inflammatory, anticarcinogenic, analgesic, counterirritant and antiarthritic properties. Numerous studies have shown increased oxidative stress in men with varicocele that is caused by dilation of the spermatic vein and increase of testicular temperature. Therefore, we aimed to assess the effect of Capsaicin on sperm parameters in rats with experimental varicocele. At first, we induced varicocele in 30 Wistar rats and, verify varicocele model only in 10 rats by assessment of sperm parameters, oxidative stress, DNA damage and persistent histone after 2 months. Of the remaining 20 varicocelised rats, half of them were treated with 2.5 mg/kg Capsaicin for two months and the other half served as control. Then, sperm tests were assessed, and the results showed that Capsaicin can restore the mean of sperm oxidative stress (38.78 ± 3.75 versus 58.37 ± 4.34; p < .05), sperm concentration (60.14 ± 7.66 versus 34.87 ± 5.78; p < .05) and motility (62.43 ± 3.10 versus 41.22 ± 5.11; p < .05) in varicocelised rats treated with Capsaicin compared to varicocelised rats that were not treat. Therefore, Capsaicin possibly with reduction of oxidative stress level could improve mean of sperm concentration and motility in varicocele condition.

Do antioxidants improve serum sex hormones and total motile sperm count in idiopathic infertile men?

OBJECTIVE

Reactive oxygen species reduce the male sex hormone levels and disrupt the hormonal balance that regulates male reproductive functions. They disrupt spermatozoa and other testicular cells. This study aimed at evaluating the effect of antioxidant treatment on serum gonadal hormones and sperm parameters in men with idiopathic infertility.

MATERIAL AND METHODS

A total of 100 idiopathic infertile men aged 23-46 years were included in the study. Control group and antioxidant treatment group consisted of 50 men each. Patients in the treatment group received oral antioxidant supplement once a day. The antioxidant supplement content included L-carnitine, L-arginine, vitamin E, vitamin C, coenzyme Q, glutathione, beta-carotene, magnesium, vitamin B12, zinc, vitamin A, vitamin B6, vitamin D3, folic acid, and selenium. Reproductive hormones and sperm parameters were compared between the groups at 6 months after starting the antioxidant therapy.

RESULTS

No significant differences were observed in the patient age (p=0.861), partner age (p=0.081), total motile sperm count (TMSC) (p=0.324), and follicle-stimulating hormone (FSH) (p=0.557), luteinizing hormone (LH) (p=0.235), and total testosterone levels (p=0.851) at baseline between the treatment and control groups. Although the mean TMSC did not increase significantly, the mean FSH (p=0.008), LH (p=0.008), and total testosterone (p=0.006) levels significantly increased from baseline to post-treatment in the treatment group. However, no significant differences from baseline to post-treatment were observed in TMSC (p=0.486), FSH (p=0.712), LH (p=0.696), and total testosterone levels (p=0.546) in the control group.

CONCLUSION

The research draws attention to the alternate treatment approaches in infertile men. Antioxidant treatment can increase the serum sex hormone levels.

Comparative analysis of tests used to assess sperm chromatin integrity and DNA fragmentation

Male infertility has a complex etiology, and many times, the cause is unknown. While routine semen analysis provides an overview of basic semen parameters, such as sperm concentration, motility, viability and morphology, a significant overlap of these parameters has been reported in fertile and infertile men. Moreover, conventional semen parameters do not reveal the cellular or molecular mechanisms of sperm dysfunctions leading to infertility. Therefore, sperm functional parameters, including sperm chromatin integrity, are evaluated to provide information on subtle sperm defects that are not routinely identified. Incomplete or defective sperm chromatin condensation increases the susceptibility of the sperm DNA to oxidative damage or other factors. To evaluate sperm chromatin integrity, different methods with varying degrees of diagnostic and prognostic capabilities are available. Among these assays, SCSA, TUNEL and SCD assays are most commonly used. While these assays rather evaluate the DNA directly for damages, the aniline blue and chromomycin A3 stains test for the quality of chromatin condensation. Thus, this review discusses and compares different methods used to evaluate sperm chromatin integrity and condensation, and their inclusion in the routine evaluation of the male infertility.

Total antioxidant capacity-Relevance, methods and clinical implications

Oxidative stress is pre-empted by an adequate level of antioxidants, which scavenge oxidants when they are produced in excess by different sources, including leukocytes and immature spermatozoa. Enzymatic antioxidants, such as superoxide dismutase, catalase and glutathione peroxidase, and several non-enzymatic antioxidants (proteins, vitamins and minerals), working as oxidant scavengers and cofactors of enzymatic antioxidants have been identified in seminal plasma. The total antioxidant capacity (TAC) is a diagnostic test that can be utilised in the male infertility workup. TAC measures the amount of total antioxidants in seminal plasma. Therefore, it provides an assessment of the reductive potential in seminal plasma. Several studies have investigated the diagnostic application of TAC in various andrology conditions. There is substantial evidence in the literature to show that infertile patients have lower seminal TAC in comparison with fertile men. Moreover, there is a positive correlation between TAC and seminal parameters, such as sperm concentration, motility and morphology. Evaluation of TAC together with reactive oxygen species (ROS) and sperm DNA fragmentation index (DFI) may be beneficial in the diagnosis of male infertility.

Diet and Nutritional Factors in Male (In)fertility-Underestimated Factors

In up to 50% of cases, infertility issues stem solely from the male. According to some data, the quality of human semen has deteriorated by 50%–60% over the last 40 years. A high-fat diet and obesity, resulting from an unhealthy lifestyle, affects the structure of spermatozoa, but also the development of offspring and their health in later stages of life. In obese individuals, disorders on the hypothalamic-pituitary-gonadal axis are observed, as well as elevated oestrogen levels with a simultaneous decrease in testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) levels. Healthy dietary models clearly correlate with better sperm quality and a smaller risk of abnormalities in parameters such as sperm count, sperm concentration and motility, and lower sperm DNA fragmentation. Apart from mineral components such as zinc and selenium, the role of omega-3 fatty acids and antioxidant vitamins should be emphasized, since their action will be primarily based on the minimization of oxidative stress and the inflammation process. Additionally, the incorporation of carnitine supplements and coenzyme Q10 in therapeutic interventions also seems promising. Therefore, it is advisable to have a varied and balanced diet based on vegetables and fruit, fish and seafood, nuts, seeds, whole-grain products, poultry, and low-fat dairy products.

Methyl parathion causes genetic damage in sperm and disrupts the permeability of the blood-testis barrier by an oxidant mechanism in mice

Methyl parathion (Me-Pa) is an extremely toxic organophosphorus pesticide still used in developing countries. It has been associated with decreased sperm function and fertility and with oxidative and DNA damage. The blood-testis barrier (BTB) is a structure formed by tight junction (TJ) proteins in Sertoli cells and has a critical role in spermatogenesis. We assessed the effect of repeated doses of Me-Pa (3-12 mg/kg/day for 5 days, i.p.) on sperm quality, lipid oxidation, DNA integrity, and BTB permeability in adult male mice and explored oxidation as a mechanism of toxicity. Me-Pa caused dose-dependent effects on sperm quality, lipoperoxidation, and DNA integrity. Testis histology results showed the disruption of spermatogenesis progression and atrophy of seminiferous tubules. The pesticide opened the BTB, as evidenced by the presence of a biotin tracer in the adluminal compartment of the seminiferous tubules. This effect was not observed after 45 days of exposure when a spermatogenic cycle had completed. The coadministration of the antioxidant α-tocopherol (50 mg/kg/day for 5 days, oral) prevented the effects of Me-Pa on sperm quality, DNA and the BTB, indicating the importance of oxidative stress in the damage generated by Me-Pa. As evidenced by immunochemistry, no changes were found in the localization of the TJ proteins of the BTB, although oxidation (carbonylation) of total proteins in testis homogenates was detected. Our results show that Me-Pa disturbs the BTB and that oxidation is involved in the observed toxic effects on sperm cells.

Coenzyme Q10 effect on semen parameters: Profound or meagre?

Coenzyme Q10 has shown promise in treating male infertility; however, there are inconsistencies across the published data. We undertook a quantitative meta-analysis by pooling data from three placebo-controlled randomised clinical trials (RCTs) in order to evaluate the efficacy of CoQ10 in improving semen parameters. Sperm count, sperm motility, sperm forward motility, sperm morphology and CoQ10 level in the seminal plasma were measured and quantitatively correlated with CoQ10 oral administration. Pooled analysis showed a significant impact of CoQ10 in improving sperm motility and forward motility, without a significant impact on sperm count, sperm morphology, ejaculate volume or seminal plasma level of CoQ10. Efficacy assessment suggested that CoQ10 shows better results at higher doses and when administered for a period of more than 3 months but not longer than 6 months. We conclude that CoQ10 has a profound effect on sperm motility and a meagre effect on all other parameters. Therefore, CoQ10 can be used for treating asthenozoospermic infertility with the dosage and duration depending upon the severity of the disorder and the patient's response to the treatment.