The effects of combined conventional treatment, oral antioxidants and essential fatty acids on sperm biology in subfertile men

The influence of oral antioxidants on men with infertility: a systemic review

OBJECTIVE

This study aims to investigate the current evidence regarding the impact of oral antioxidant supplementation on semen parameters of infertile men.

MATERIALS AND METHODS

We conducted a systematic search of PubMed, and Cochrane electronic databases, adhering to modified Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The focus was on studies exploring the effects of antioxidant therapy on infertile men, with an examination of antioxidants in terms of types, doses, rationale for use, and their impact on semen parameters measures.

RESULTS

A total of 18 studies that met the inclusion criteria were included in this study. Out of these, 14 studies reported a significantly positive influence of antioxidant therapy on basic semen parameters and advanced sperm function. These comprised 11 randomized clinical trials and 7 prospective studies. Commonly utilized antioxidants included Vitamin E, Vitamin C, carnitines, co-enzyme Q10, N-acetyl cysteine, zinc, selenium, folic acid, and lycopene.

CONCLUSIONS

Overall, antioxidants generally demonstrate a favorable effect on semen parameters of infertile men. However, further research is necessary to pinpoint the optimal antioxidant regimen that can be applied safely and effectively in clinical practice.

Impact of Antioxidants on Conventional and Advanced Sperm Function Parameters: An Updated Review

Antioxidants include diverse exogenous and endogenous compounds that can neutralize free radical activity, which ultimately protects sperm from oxidative stress (OS). Nevertheless, a controlled balance between oxidation and reduction is of paramount importance for cellular function. Excessive use of antioxidants should be avoided. A combination of antioxidants has been utilized to obtain a synergetic effect in the treatment of male infertility. Antioxidants have been shown to have a positive effect on semen parameters with a decrease in DNA damage. Future large randomized controlled trials are needed to determine the real impact of antioxidants on semen parameters, reproductive outcomes, and DNA integrity.

Effect of Five Different Antioxidants on the Effectiveness of Goat Semen Cryopreservation

The effective combination of semen cryopreservation and artificial insemination has a positive effect on the conservation of germplasm resources, production and breeding, etc. However, during the process of semen cryopreservation, the sperm cells are very susceptible to different degrees of physical, chemical, and oxidative stress damage. Oxidative damage is the most important factor that reduces semen quality, which is affected by factors such as dilution equilibrium, change of osmotic pressure, cold shock, and enzyme action during the freezing-thawing process, which results in the aggregation of a large amount of reactive oxygen species (ROS) in sperm cells and affects the quality of semen after thawing. Therefore, the method of adding antioxidants to semen cryoprotective diluent is usually used to improve the effect of semen cryopreservation. The aim of this experiment was to investigate the effects of adding five antioxidants (GLP, Mito Q, NAC, SLS, and SDS) to semen cryoprotection diluent on the cryopreservation effect of semen from Saanen dairy goats. The optimal preservation concentrations were screened by detecting sperm viability, plasma membrane integrity, antioxidant capacity, and acrosomal enzyme activities after thawing, and the experimental results were as follows: the optimal concentrations of GLP, Mito Q, NAC, SLS, and SDS added to semen cryopreservation diluent at different concentrations were 0.8 mg/mL, 150 nmol/L, 0.6 mg/mL, 0.15 mg/ mL, 0.6 mg/mL, and 0.15 mg/mL. The optimal concentrations of the five antioxidants were added to the diluent and analyzed after 1 week of cryopreservation, and it was found that sperm viability, plasma membrane integrity, and mitochondrial activity were significantly enhanced after thawing compared with the control group (P < 0.05), and their antioxidant capacity was significantly enhanced (P < 0.05). Therefore, the addition of the above five antioxidants to goat sperm cryodilution solution had a better enhancement of sperm cryopreservation. This study provides a useful reference for exploring the improvement of goat semen cryoprotection effect.

Omega 6/Omega 3 Ratio Is High in Individuals with Increased Sperm DNA fragmentation

An imbalance between omega-6 and omega-3 fatty acids in sperm has been linked with lipid peroxidation and DNA damage in sperm, indicating a possible correlation to fertility potential. This cross-sectional study involved 56 infertile men (aged 25-45), and assessed the relationship between the omega-6 to omega-3 fatty acid ratio in sperm and seminal plasma with sperm DNA fragmentation. Individuals were categorized based on high or low levels of sperm DNA fragmentation according to two tests (TUNEL and SCSA assay less or greater than 10 and 30%, respectively), and their fatty acid composition, as well as sperm functional tests, were analyzed. Results showed that men with high DNA fragmentation exhibited higher percentages of total saturated, monounsaturated, and omega-6 to omega-3 fatty acid ratios in both sperm (P < 0.001) and seminal plasma (P < 0.001) compared to men with low DNA fragmentation. The percentage of sperm lipid peroxidation, and residual histone (P < 0.05) were higher, while the percentage of sperm motility (P < 0.001) was lower in the former compared to the latter group. Moreover, Pearson's correlation revealed positive associations between the omega-6 to omega-3 fatty acid ratio with sperm lipid peroxidation, DNA fragmentation, and residual histones in both sperm and seminal plasma. Overall, these observations suggest that consumption of omega-3 fatty acids may be related to male fertility potential, as it appears that individuals with a high percentage of omega-3 fatty acids have better sperm quality compared to men with a lower omega-3 fatty acid.

High sperm DNA fragmentation: do we have robust evidence to support antioxidants and testicular sperm extraction to improve fertility outcomes? a narrative review

To date, infertility affects 10% to 15% of couples worldwide. A male factor is estimated to account for up to 50% of cases. Oral supplementation with antioxidants could be helpful to improve sperm quality by reducing oxidative damage. At the same time, there is a growing interest in the literature on the use of testicular sperm in patients with high DNA fragmentation index (DFI). This narrative review aims to evaluate the effectiveness of supplementation of oral antioxidants in infertile men with high DFI compared to testicular sperm retrieval. The current evidence is non-conclusive because of serious risk of bias due to small sample sizes and statistical methods. Further large well-designed randomised placebo-controlled trials are still required to clarify the exact role of these to different therapeutic approaches.

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.

Antioxidants in Male Infertility-If We Want to Get This Right We Need to Take the Bull by the Horns: A Pilot Study

Antioxidant therapy should be reserved for infertile patients who actually exhibit signs of oxidative stress (OS). Nevertheless, there is no consensus regarding the measure of the primary endpoint and the assay that should be used. The formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG), an early marker of sperm DNA oxidation (SDO), was analyzed using flow cytometry, in men at a University hospital setup for infertility treatment. Similar to conventional semen parameters, 8-OHdG assay was validated on fresh semen samples to reduce the variability of results. SDO was associated with semen volume, sperm concentration, leucocytes and round cells, but not with age, body mass index, sperm DNA fragmentation (SDF) or OS. Whether the semen samples were normal or subnormal according to the WHO criteria, the expression of 8-OHdG was not different. Receiver operating characteristic curve analysis could discriminate two independent populations. Both SDF and SDO were independently expressed. A high SDF did not reveal a high SDO and vice versa. The thresholds for SDO have been established, but vary with the techniques used. The methodology for SDO needs to be further validated and optimized on a larger clinically defined patient population before the outcome measure is fit to monitor antioxidant therapy in male infertility.

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

BACKGROUND

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

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

COVID-19 and Male Infertility: Is There a Role for Antioxidants?

Coronavirus disease 19 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), jeopardizes male fertility because of the vulnerability of the male reproductive system, especially the testes. This study evaluates the effects of the virus on testicular function and examines the potential role of antioxidants in mitigating the damage caused by oxidative stress (OS). A comprehensive PubMed search examined exocrine and endocrine testicular function alteration, the interplay between OS and COVID-19-induced defects, and the potential benefit of antioxidants. Although the virus is rarely directly detectable in sperm and testicular tissue, semen quality and hormonal balance are affected in patients, with some changes persisting throughout a spermatogenesis cycle. Testicular pathology in deceased patients shows defects in spermatogenesis, vascular changes, and inflammation. Acute primary hypogonadism is observed mainly in severely infected cases. Elevated OS and sperm DNA fragmentation markers suggest redox imbalance as a possible mechanism behind the fertility changes. COVID-19 vaccines appear to be safe for male fertility, but the efficacy of antioxidants to improve sperm quality after infection remains unproven due to limited research. Given the limited and inconclusive evidence, careful evaluation of men recovering from COVID-19 seeking fertility improvement is strongly recommended.

Role of antioxidants in fertility preservation of sperm - A narrative review

Male fertility is affected by multiple endogenous stressors, including reactive oxygen species (ROS), which greatly deteriorate the fertility. However, physiological levels of ROS are required by sperm for the proper accomplishment of different cellular functions including proliferation, maturation, capacitation, acrosomal reaction, and fertilization. Excessive ROS production creates an imbalance between ROS production and neutralization resulting in oxidative stress (OS). OS causes male infertility by impairing sperm functions including reduced motility, deoxyribonucleic acid damage, morphological defects, and enhanced apoptosis. Several in-vivo and in-vitro studies have reported improvement in quality-related parameters of sperm following the use of different natural and synthetic antioxidants. In this review, we focus on the causes of OS, ROS production sources, mechanisms responsible for sperm damage, and the role of antioxidants in preserving sperm fertility.

Impact of Antioxidant Therapy on Natural Pregnancy Outcomes and Semen Parameters in Infertile Men: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

PURPOSE

Seminal oxidative stress (OS) is a recognized factor potentially associated with male infertility, but the efficacy of antioxidant (AOX) therapy is controversial and there is no consensus on its utility. Primary outcomes of this study were to investigate the effect of AOX on spontaneous clinical pregnancy, live birth and miscarriage rates in male infertile patients. Secondary outcomes were conventional semen parameters, sperm DNA fragmentation (SDF) and seminal OS.

MATERIALS AND METHODS

Literature search was performed using Scopus, PubMed, Ovid, Embase, and Cochrane databases. Only randomized controlled trials (RCTs) were included and the meta-analysis was conducted according to PRISMA guidelines.

RESULTS

We assessed for eligibility 1,307 abstracts, and 45 RCTs were finally included, for a total of 4,332 infertile patients. We found a significantly higher pregnancy rate in patients treated with AOX compared to placebo-treated or untreated controls, without significant inter-study heterogeneity. No effects on live-birth or miscarriage rates were observed in four studies. A significantly higher sperm concentration, sperm progressive motility, sperm total motility, and normal sperm morphology was found in patients compared to controls. We found no effect on SDF in analysis of three eligible studies. Seminal levels of total antioxidant capacity were significantly higher, while seminal malondialdehyde acid was significantly lower in patients than controls. These results did not change after exclusion of studies performed following varicocele repair.

CONCLUSIONS

The present analysis upgrades the level of evidence favoring a recommendation for using AOX in male infertility to improve the spontaneous pregnancy rate and the conventional sperm parameters. The failure to demonstrate an increase in live-birth rate, despite an increase in pregnancy rates, is due to the very few RCTs specifically assessing the impact of AOX on live-birth rate. Therefore, further RCTs assessing the impact of AOX on live-birth rate and miscarriage rate, and SDF will be helpful.

Effect of Aqueous Extract of Maca Addition to an Extender for Chilled Canine Semen

Simple Summary

The wide use of artificial insemination in dogs justifies the development of new strategies to prevent the reduction of fertilizing ability of stored semen. In recent years, the use of plant antioxidant supplementation has become increasingly popular. Maca (Lepidium meyenii) is an Andean edible root with antioxidant properties. The effectiveness of the oral supplementation of Maca in improving fresh semen quality and quantity and cooling or freezing ability has already been reported. This is the first in vitro study on the effects of aqueous extract of Maca on canine spermatozoa. The addition of low concentrations of aqueous extract of Maca to the canine chilled extender had positive effects only until 24 h of storage, increasing hyperactivation of sperm cells and preserving DNA integrity of spermatozoa in short-term storage. Meanwhile, a high concentration of Maca had an immediately deleterious effect on semen quality.

Abstract

Antioxidant supplementation has been proposed as a new strategy to improve the long-term preservation of semen. The aim of this study was to evaluate the effect of Maca supplementation of semen extender on quality-related canine semen parameters during cooling. Ejaculates from nine dogs were cooled for 7 days in the absence (control group) or in the presence of 10, 20 and 50 μL/mL of an aqueous extract of Maca. Sperm were evaluated for sperm viability, motility, DNA fragmentation and lipid peroxidation after 3 h, 24 h, 4 days and 7 days of storage. The addition of 10 μL/mL of Maca preserved sperm DNA and plasma membrane integrity at 3 h and increased sperm curvilinear velocity after 24 h. Treatment with 20 and 50 μL/mL of Maca increased the percentage of hyperactivated sperm after 3 h. Moreover, semen treated with 20 μL/mL of Maca decreased lipid peroxidation at 24 h. A significant reduction of sperm DNA and plasma membrane integrity as well as of kinetics parameters between 3 and 24 h of refrigerated storage with the higher concentration tested was observed. Although Maca was not able to protect canine semen with extended refrigeration storage time, it increased hyperactivation and preserved DNA integrity in short-term storage.

Carryover effects of feeding bulls with an omega-3-enriched-diet-From spermatozoa to developed embryos

The impact of omega-3 nutritional manipulation on semen cryosurvival and quality post thawing is controversial. Our aim was to examine how feeding bulls with omega-3 supplementation from different sources affects the spermatozoa quality parameters. Fifteen Israeli Holstein bulls were fed for 13 weeks with a standard ration top-dressed with encapsulated-fat supplementation: fish or flaxseed oil or saturated fatty acids (control). Ejaculates were collected before, during, and after the feeding trial. Frozen–thawed samples were evaluated by a flow cytometer for spermatozoa viability, mitochondrial membrane potential, the level of reactive oxygen species (ROS), acrosome membrane integrity, DNA fragmentation, phosphatidylserine translocation, and membrane fluidity. Both fish and flaxseed oil treatment resulted in lower ROS levels vs. control groups, during and after the feeding trial. Fewer spermatozoa with damaged acrosomes were observed in the fish oil group after the feeding trial. The spermatozoa membrane fluidity was altered in both the fish and flaxseed oil groups throughout the feeding trial, but only in the flaxseed oil group after the feeding trial. The proportion of spermatozoa with fragmented DNA was lower in the flaxseed oil group after the feeding trial. The spermatozoa fertilization competence did not differ between groups however, blastocyst formation rate was higher in the fish and flaxseed oil groups relative to the control. This was associated with differential gene expression in the blastocysts. Overall, the omega-3-enriched food improved the spermatozoa characteristics; this was further expressed in the developing blastocysts, suggesting a carryover effect from the spermatozoa to the embryos.

COVID-19, Oxidative Stress and Male Reproduction: Possible Role of Antioxidants

Coronavirus disease 2019 (COVID-19) involves a complex pathogenesis and with the evolving novel variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the long-term impacts of the unceasing COVID-19 pandemic are mostly uncertain. Evidence indicates deleterious impact of this disease upon male reproductive health. It is concerning that COVID-19 may contribute to the already global declining trend of male fertility. The adverse impacts of COVID-19 on male reproduction may primarily be attributed to the induction of systemic inflammatory responses and oxidative stress (OS), which operate as a vicious loop. Bringing the systemic inflammation to a halt is critical for ‘putting out’ the ‘cytokine storm’ induced by excessive reactive oxygen species (ROS) generation. The possibility of OS playing a prime role in COVID-19-mediated male reproductive dysfunctions has led to the advocacy of antioxidant therapy. An array of antioxidant defense medications has shown to be effective in experimental and clinical studies of COVID-19. The present review thus discusses the possibilities as to whether antioxidant drugs would contribute to combating the SARS-CoV-2 infection-induced male reproductive disruptions, thereby aiming at kindling research ideas that are needed for identification and treatment of COVID-19-mediated male reproductive impairments.

Enhancement of sperm quality and fertility-related parameters in Hubbard grandparent rooster fed diets supplemented with soybean lecithin and vitamin E

The purpose of this study was to investigate the effect of dietary supplementation of different levels of soybean lecithin and vitamin E on semen quality parameters and some reproductive hormones in Hubbard grandparent roosters. The experiment was conducted in a 3 × 2 factorial arrangement with 3 levels of soybean lecithin (0, 1, and 2%) and 2 levels of vitamin E (0 and 300 mg/kg). Semen samples were collected on d 0, 20, 40 and 60 of the experiment and analyzed. Adding 1% soybean lecithin and vitamin E into the diet increased semen volume and sperm concentration, membrane integrity and viability (P < 0.05). Supplementing diets with 1 or 2% lecithin in addition to vitamin E significantly improved total motility and progressive motility (P < 0.05). Vitamin E significantly increased the amplitude of lateral head displacement (ALH) of sperm (P < 0.05). Although there was no effect on LH and FSH when diets were supplemented with vitamin E and 1 or 2% lecithin, testosterone concentration was increased (P < 0.05). Malondialdehyde (MDA) concentration was significantly lower in all 3 treatments containing vitamin E (P < 0.05). It can be concluded that supplementation of rooster diets with vitamin E and 1% lecithin can improve fertility related parameters in Hubbard grandparent roosters.

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.

Fatty acid compositions of immature and mature testis are differently responsive to dietary docosahexasenoic acid during development in rats exposed to prenatal ethanol

BACKGROUND

Ethanol (EtOH) exposure impairs, but docosahexaenoic acid (DHA) supports testis functions. This study investigated whether dietary DHA and prenatal EtOH exposure affected fatty acid profiles equally in immature and mature testis during developmental stages.

METHODS

Female rats were exposed to ± EtOH (3g/kg BW, twice a day via gavage) throughout pregnancy, while consuming a diet supplemented ± DHA (1.4%, w/w). Pups were continued on their mother's diet after weaning with testes collected for fatty acid analysis at different stages of reproductive development, at gestational day 20 (GD20) and postnatal day (PD) 4, 21, 49, and 90, to present fetal, neonatal, weaning, prepubertal and adult stages, respectively.

RESULTS

Regardless of EtOH exposure, dietary DHA significantly increased in testis DHA at all ages, with testis at weaning and prepuberty being more responsive to the diet (p<0.0002). Immature testis at GD20 and PD4 contained more DHA than n-6 docosapentaenoic acid (n-6 DPA) compared to mature testis while being well responsive to the maternal DHA diet through gestation and lactation. The level of n-6 very long chain fatty acids and (VLCFA) and n-6 DPA, distinctively increased from weaning and prepuberty, respectively, and were not reduced by the DHA diet at prepuberty and adulthood. Prenatal EtOH minimally affected testis fatty acids during development.

CONCLUSION

Immature and mature testis responds differently to dietary DHA. The age around sexual maturity might be a critical time for dietary intervention as testis was more responsive to diet at this time point. The increase in DPA and n-6 VLCFA in matured testis while not affected by dietary DHA, indicates their critical roles in male reproductive function in rodents.

The effect of N-acetyl cysteine consumption on men with abnormal sperm parameters due to positive history of COVID-19 in the last three months

Male infertility is an important factor accounting for 40-50% of infertility cases that may be due to disturbance in one of the parameters as concentration, motility and morphology observed in one or two semen analysis with an interval of 1 and 4 weeks. COVID-19 may affect male fertility through virus division, cytotoxic effects on testicular tissue and immunopathological effect. N-acetyl cysteine (NAC) improved sperm concentration and acrosome reaction while reducing reactive oxygen species (ROS) and oxidation of sperm DNA. This interventional study was conducted on 200 men who were referred to private infertility clinics for female factor (their previous semen analysis was normal) and got COVID-19 infection in the last 3 months showing an impairment of the latest semen analysis due to COVID. Men were placed in two groups of control (n = 100) and intervention (NAC consumption). Subjects who got COVID-19 infection had a significant impairment of sperm quality (sperm concentration, sperm motility, and normal sperm morphology) compared to their semen analysis evaluated before the COVID-19 infection. NAC consumption significantly improved sperm total motility, sperm morphology and sperm concentration. COVID-19 infection has a negative effect on sperm parameters. NAC supplementation may have positive effect on sperm parameters.

Adverse effects of oxytetracycline and enrofloxacin on the fertility of Saanen bucks

This study aimed to determine the adverse effects of oxytetracycline and enrofloxacin application on the fertility of Saanen bucks. For this purpose, twenty-four bucks were divided into three groups. Group I (control group) received only 5 ml of 0.9% NaCl for 7 days, group II was given a single dose of 20 mg/kg oxytetracycline and group III was given at a dose of 2.5 mg/kg per day for 7 days intramuscularly. Serum and semen samples were collected from the bucks at post-treatment 1, 3, 5, 7, and 9 days and examined spermatological parameters (quantity, motility, density, abnormal sperm ratio, and live-dead sperm ratio), serum testosterone levels (with ELISA) and sperm DNA parameters (with Comet assay). The results showed no change in sperm volume, abnormal sperm rate, and dead-live sperm ratio in group II and III following oxytetracycline and enrofloxacin administration. However, a decrease in sperm density, sperm motility, mass activity, and testosterone levels, and an increase in sperm DNA damage were detected. These spermatological parameters (density, motility, mass activity) and testosterone levels were less decreased and sperm DNA damage was less increased in group II than group III. The greater damage in group III may be attributed to the longer duration of enrofloxacin administration compared to oxytetracycline and the effect of enrofloxacin on DNA. The results obtained from this study suggest that usage of oxytetracycline and especially enrofloxacin should be restricted and antibiotics with fewer side effects on sperm should be preferred in Saanen bucks during the reproduction period.

Comparison of 3- and 6-Month Outcomes of Combined Oral L-Carnitine Fumarate and Acetyl-L-Carnitine Therapy, Included in an Antioxidant Formulation, in Patients with Idiopathic Infertility

The male factor is responsible for infertility in about 35-40% of all cases. Idiopathic oligo- and/or astheno- and/or therato-zoospermia is one of the most common male fertility disorders and remains a significant therapeutic challenge. The primary cause of idiopathic male infertility remains unknown but seems to be associated with oxidative stress. Objective: The use of antioxidative formulation to improve qualitative and quantitative deficiencies in the male gametes.In total, 78 subjects were treated with a combination of 1,725 mg L-carnitine fumarate, 500 mg acetyl-L-carnitine, 90 mg vitamin C, 20 mg coenzyme Q10, 10 mg zinc, 200 µg folic acid, 50 µg selenium, and 1.5 µg vitamin B12 (Proxeed® Plus, Sigma-Tau, Italy) for 6 months; the preparation was taken twice daily from the time idiopathic infertility was diagnosed. Basic seminal parameters were evaluated by a European Society of Human Reproduction and Embryology (ESHRE) -certified embryologist following the fifth edition of the World Health Organisation (2010) guidelines at three time points: at baseline and 3 and 6 months of treatment.Improvements in semen parameters (differing in terms of dynamics) were evident at 3 months and gradually improved over the 6 months of treatment. Each parameter: sperm concentration, total sperm count, sperm total and progressive motility improved significantly after treatment except for the percentage of sperm of abnormal morphology and ejaculate volume.Proxeed Plus was effective for patients with idiopathic infertility; however, a long treatment period is needed to achieve optimal results.

Freeze-thawing impairs the motility, plasma membrane integrity and mitochondria function of boar spermatozoa through generating excessive ROS

Background

Cryopreservation is an efficient way to store spermatozoa and is closely associated with the quality of sperm after the freeze-thaw process. During freeze-thaw cycling, excessive reactive oxygen species (ROS) are produced, and the effects of ROS on boar sperm during cryopreservation have not been identified.

Results

In this study, we evaluated the quality of boar spermatozoa in different steps of cryopreservation (extension, cooling, and thawing for 30 min and 240 min) with or without boar-sperm antioxidant (N-acetylcysteine (NAC)). The ROS levels, sperm motility, plasma membrane integrity, mitochondrial activity, sperm chromatin structure, ATP content, and sperm apoptosis were assayed. After thawing, the ROS level and sperm apoptosis were significantly increased, and the sperm motility, plasma membrane integrity, mitochondrial activity, sperm chromatin structure, and ATP content were significantly impaired compared with those at the extension period and cooling period. Moreover, the addition of N-acetyl L-cysteine (NAC) reversed these changes.

Conclusion

The freeze-thawing of boar spermatozoa impaired their motility, plasma membrane, mitochondrial activity, sperm chromatin structure and apoptosis by producing excessive ROS. Thus, the downregulation of ROS level by antioxidants, especially the NAC, is important for manufacturing frozen pig sperm to increase reproductive cells and livestock propagation, as well as to improve the application of frozen semen in pigs worldwide.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-021-02804-1.

A Meta-Analysis of the Efficacy of L-Carnitine/L-Acetyl-Carnitine or N-Acetyl-Cysteine in Men With Idiopathic Asthenozoospermia

The meta-analysis was performed to access efficacy of L-carnitine/L-acetyl-carnitine (LC/LAC) and N-acetyl-cysteine (NAC) in men with idiopathic asthenozoospermia. We researched PubMed, EMBASE, and Cochrane Library databases and references to related articles. Finally, seven articles including 621 patients were analyzed. The results indicated that LC/LAC and NAC had a considerable improvement in sperm motility (p = .03 and p < .0001, respectively) and normal morphology (p = .006, p = .0002, respectively) compared with the placebo group. Besides, NAC had a significantly greater increase in sperm concentration (p < .00001) and ejaculate volume (p = .002) compared with the placebo group, and there was no significant difference in LC/LAC. For the analysis of serum hormones, NAC had no obvious differences in improving the serum testosterone, luteinizing hormone, follicle-stimulating hormone, and prolactin compared with non-treatment group. Conclusively, LC/LAC and NAC showed a greater improvement in sperm motility and normal morphology. Moreover, NAC has a positive effect on sperm concentration and ejaculate volume, whereas no obvious effect was observed in serum hormones.

Effect of antioxidant supplementation containing L-carnitine on semen parameters: a prospective interventional study

Objective:

One of the remarkable causes of infertility in men is oxidative stress having a reducing effect on their reproductive function. In the present study, we investigated the efficacy of supplementation with antioxidants and L-Carnitine (contained in Androferti) on semen parameters.

Methods:

We included 180 infertile male patients diagnosed with idiopathic oligoastenoteratozoospermia (OAT) in this study, and we analyzed the semen sample from 59 patients before and after oral antioxidant treatment, with the commercial name of Androferti (containing 1500 mg of L-Carnitine, 60 mg of vitamin C, 20 mg of coenzyme Q10, 10 mg of vitamin E, 10 mg of zinc, 200 µg of vitamin B9, 50 µg of selenium, 1 µg of vitamin B12). All of the patients received Androferti twice a day for 3 months.

Results:

There were significant improvements in the sperm concentration (p=0.004) after the antioxidant supplementation. There was also a meaningfully improvement in sperm morphology (p=0.01) after treatment. However, sperm motility was not significantly altered after antioxidant treatment (p=0.2).

Conclusions:

Antioxidants supplementation containing 1500 mg L-carnitine can improve the semen quality in infertile men diagnosed with idiopathic OAT. However, further studies are required to determine the antioxidant effects on reproduction function.

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 role of N-acetyl-cysteine (NAC) orally daily on the sperm parameters and serum hormones in idiopathic infertile men: A systematic review and meta-analysis of randomised controlled trials

The meta-analysis was performed to access the role of N-acetyl-cysteine (NAC) orally daily on the sperm parameters and serum hormones in idiopathic infertile men. Randomised controlled trials (RCTs) were retrieved using PubMed, EMBASE and Cochrane register databases. The references of included studies were also searched. Finally, three articles including 431 infertile men were analysed. The results indicated that the NAC group had a considerable improvement in sperm concentration (mean difference [MD], 3.80; p < .00001), ejaculate volume (MD, 0.69; p = .002), sperm motility (MD, 4.69; p < .0001) and normal morphology (MD, 1.68; p = .0002) compared with the placebo group. However, in terms of serum hormones, the NAC group did not show significant difference in increasing the serum levels of testosterone (MD, 1.35; p = .21), luteinising hormone (MD, 0.82; p = .40), follicle-stimulating hormone (MD, -7.48; p = .29) and prolactin (MD, -0.34; p = .32) compared with the placebo group. In conclusion, NAC orally daily produced a greater improvement in sperm concentration, ejaculate volume, sperm motility and normal morphology for idiopathic infertile men, whereas no significant influence in serum hormones, which required more high-quality RCTs with sufficient sample sizes and statistics to prove.

Can the biological mechanisms of ageing be corrected by food supplementation. The concept of health care over sick care

"From care for the sick to care for health" implies that age-related diseases and discomforts, which impair the quality of life, should be prevented rather than treated. Healthy lifestyle and nutrition, and hormone supplementation - when needed - are of crucial importance. Food supplementation with nutraceuticals composed of vitamins, oligo-minerals, plant extracts and essential amino- and fatty acids should reduce age-related oxidative and epigenetic damage to DNA, and inhibit inflammatory and metabolic impairment. This study of the potential beneficial effects of novel nutraceuticals on the biological mechanisms of physical and mental ageing suggests these supplements may be scientifically justified. In the absence of adverse side effects and the expected favourable effect on the quality-adjusted life years, the benefit over risk ratio of nutraceutical supplementation should be positive.

Effects of coadministration of DHA and vitamin E on spermatogram, seminal oxidative stress, and sperm phospholipids in asthenozoospermic men: a randomized controlled trial

BACKGROUND

It is unknown which compounds in spermatozoa or seminal plasma may be involved in the regulation of sperm motility.

OBJECTIVES

The aim of this study was to investigate the effects of DHA (22:6n-3), vitamin E, and their probable interactions in men with asthenozoospermia.

METHODS

A factorial, randomized, double-blind, placebo-controlled trial was conducted in infertility clinics in Tehran, Iran. The participants were idiopathic asthenozoospermic men aged 20-45 y, with normal endocrine function. Their concentration of spermatozoa and percentage of morphologically normal spermatozoa were equal to or above the lower reference limits, according to the fifth edition of the WHO guideline. Out of 717 men referred to the infertility clinics, 180 asthenozoospermic men were randomly assigned to 1 of 4 groups according to stratified blocked randomization by age and sperm concentration. Participants took daily 465 mg DHA plus 600 IU vitamin E (DE), 465 mg DHA plus placebo (DP), 600 IU vitamin E plus placebo (EP), or both placebo capsules (PP) for 12 wk. Sperm characteristics, oxidative stress of seminal plasma, serum and sperm membrane fatty acids, dietary intakes, anthropometric measurements, and physical activity were measured at baseline and after 12 wk.

RESULTS

After the intervention, mean ± SD sperm progressive motility was greater in the DE group (27.9 ± 2.8) than in the DP (25.7 ± 3.4), EP (26.1 ± 2.8), and PP (25.8 ± 2.6) groups (P < 0.05). Sperm count (P = 0.001) and concentration (P = 0.044) increased significantly in the DE group compared with the other 3 groups, whereas other semen parameters were not significantly different between the groups after the intervention. Serum concentrations of n-3 PUFAs were significantly higher in the DE and DP groups than in the EP and PP groups.

CONCLUSIONS

Combined DHA and vitamin E supplements led to increased sperm motility; however, no significant changes occurred in sperm morphology and vitality in asthenozoospermic men.This trial was registered at clinicaltrials.gov as NCT01846325.

Relevance of Fatty Acids to Sperm Maturation and Quality

Almost 50% of infertility cases are associated with human male infertility. The sperm membrane is a key structure influencing sperm morphology and function in normal and pathological conditions. The fatty acid profile determines the performance not only of sperm motility but also of acrosomal reaction and sperm-oocyte fusion. This review presents available knowledge on the role of fatty acid composition in human sperm and spermatogenesis and discusses the influence of dietary fatty acids on the sperm fatty acid profile. Recent studies in biological sciences and clinical researches in this field are also reported. The topic object of this review has potential application in medicine by identifying potential causes of infertility.

Dietary polyunsaturated fatty acids affect volume and metabolism of Drosophila melanogaster sperm

Dietary fatty acids can accumulate in sperm and affect their function in vertebrates. As Drosophila melanogaster shares several pathways of lipid metabolism and shows similar lipid-dependent phenotypes but lacks some hormones that in vertebrates regulate lipid metabolism, there is currently no clear prediction as to how dietary fatty acids affect the sperm of D. melanogaster. We manipulated the amount and identity of dietary polyunsaturated fatty acids (PUFA) in the food of D. melanogaster males (a treatment known to affect membrane fluidity) and measured changes in sperm parameters. We found that (a) males reared on food containing PUFA-rich, plant-derived lipids showed a slower increase in sperm volume over male age compared to males reared on yeast-derived lipid food which is richer in saturated fatty acids. (b) The resistance of sperm membrane integrity to osmotic stress was not altered by dietary lipid treatment, but (c) food containing yeast-derived lipids induced a 46% higher in situ rate of production of reactive oxygen species in sperm cells. These findings show that dietary lipids have similar effects on sperm parameters in Drosophila as in vertebrates, affect some, but not all, sperm parameters and modulate male reproductive ageing. In concert with recent findings of sex-specific seasonal variation of diet choice in the wild, our results suggest a substantial dietary impact on the dynamics of male reproduction in the wild.

Mass Spectrometry Reveals New Insights into the Production of Superoxide Anions and 4-Hydroxynonenal Adducted Proteins in Human Sperm

The free-radical theory of male infertility suggests that reactive oxygen species produced by the spermatozoa themselves are a leading cause of sperm dysfunction, including loss of sperm motility. However, the field is overshadowed on several fronts, primarily because: i) the probes used to measure reactive oxygen species (ROS) are imprecise; and ii) many reports suggesting that oxygen radicals are detrimental to sperm function add an exogenous source of ROS. Herein, a more reliable approach to measure superoxide anion production by human spermatozoa based on MS analysis is used. Furthermore, the formation of the lipid-peroxidation product 4-hydroxynonenal (4-HNE) during in vitro incubation using proteomics is also investigated. The data demonstrate that neither superoxide anion nor other free radicals that cause 4-HNE production are related to the loss of sperm motility during incubation. Interestingly, it appears that many of the 4-HNE adducted proteins, found within spermatozoa, originate from the prostate. A quantitative SWATH analysis demonstrate that these proteins transiently bind to sperm and are then shed during in vitro incubation. These proteomics-based findings propose a revised understanding of oxidative stress within the male reproductive tract.

The association between serum vitamin D, fertility and semen quality: A systematic review and meta-analysis

PURPOSE

A number of studies have examined the association between vitamin D, fertility and semen quality, however, findings have been inconclusive. Herein, we systematically reviewed available observational studies to elucidate the overall relationship between vitamin D, fertility and semen quality in adult population.

METHODS

PubMed, Cochrane's Library, Science Direct, Scopus, Google Scholar and ISI Web of Science databases were searched until December 2018 for all available studies evaluating the association between vitamin D, fertility and semen quality. The Newcastle-Ottawa Quality Assessment Scale was used to examine the quality of each study.

RESULTS

A total of 18 studies out of 1843 met our inclusion criteria and were included in our systematic review and meta-analysis. Serum 25(OH)D3 was significantly higher in fertile subjects compared to infertile ones (WMD -0.63; 95% CI, -1.06 to -0.21; P = 0.003). Furthermore, there was a significant association between serum 25(OH)D, sperm motility (WMD -5.84; 95% CI, -10.29 to -1.39; P = 0.01) and sperm progressive motility (WMD -5.24; 95% CI, -8.71 to -1.76; P = 0.003).

CONCLUSION

Our findings add to the existing literature supporting the concept that nutrition, especially vitamin D, plays an important role in men's sexual health. It should be noted that because of significant heterogeneity among the included studies, caution is warranted when interpreting the results. Further well-designed prospective cohort studies and clinical trials are needed for better understanding of the relationship between vitamin D and fertility and its components.

Effects of N-acetyl-cysteine supplementation on sperm quality, chromatin integrity and level of oxidative stress in infertile men

BACKGROUND

Infertile men have higher levels of semen reactive oxygen species (ROS) than fertile men. High levels of semen ROS can cause sperm dysfunction, sperm DNA damage and reduced male reproductive potential. This study investigated the effects of supplementation with N-acetyl-cysteine (NAC) on the sperm quality, chromatin integrity and levels of oxidative stress in infertile men.

METHODS

The study was carried out in the unit of ACECR Infertility Research Center, Qom, Iran. The patients consisted of 50 infertile men with asthenoteratozoospermia who received NAC (600 mg/d) orally for 3 months, after which they were compared with pre-treatment status. Semen was analyzed according to WHO (2010), followed by the assessment of protamine content [chromomycin A3 (CMA3)] and DNA integrity [terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)]. Oxidative stress markers, i.e. total antioxidant capacity (TAC) and malondialdehyde (MDA), as well as hormonal profile (LH, FSH, Testosterone and Prolactin) were determined by ELISA kit.

RESULTS

After NAC treatment, patients' sperm count and motility increased significantly whereas abnormal morphology, DNA fragmentation and protamine deficiency showed significant decreases compared to pre-treatment levels (P < 0.05). Hormonal profile improvement was associated with lowered FSH and LH levels and increased amount of testosterone (P < 0.05). TAC significantly increased and MDA decreased with an inverse significant correlation between TAC and MDA (P < 0.05).

CONCLUSION

NAC oral supplementation may improve sperm parameters and oxidative/antioxidant status in infertile males.

Nitrite-induced testicular toxicity in rats: therapeutic potential of walnut oil

Objective:

To determine the impact of walnut oil on nitrite-induced testicular toxicity in Sprague-Dawley (SD) rats. Available evidence suggests that walnut oil contains high levels of important unsaturated fatty acids including alpha-linolenic acid (ALA) and omega-3; nitrite is a reproductive toxicant that causes the loss of germ cells in the seminiferous tubules and generates oxidative stress in the testes, thus reducing sperm counts and affecting sperm morphology.

Methods:

This study included 24 male and 24 female adult SD rats. The male rats randomly assigned to Group A (controls) were given normal saline 2 ml/kg. The rats in Groups B, C, and D were given 50mg/kg body weight (bwt) of walnut oil, 0.08 mg/kg bwt of nitrite, and 0.08 mg/kg bwt of nitrite + 50 mg/kg of walnut oil respectively for 28 days via gastric gavage. Tested parameters included: testicular histology, sperm parameters, reproductive hormones, fertility, malondialdehyde (MDA), superoxide dismutase (SOD), reduced glutathione, and catalase (CAT).

Results:

A severe decrease in spermatogenic cell series, hypocellularity, tubular atrophy, decreased sperm quality, and increased MDA levels were observed in the rats given nitrite only when compared to controls. Rats given 50 mg/kg of walnut oil had significant growth of seminiferous epithelium compared to controls. The rats given walnut oil and nitrite had significant growth of seminiferous epithelium, improved sperm quality, and had decreased MDA levels.

Conclusion:

Walnut oil attenuated the deleterious effects of nitrite to the testes, reduced oxidative stress, and promoted spermatogenesis.

Docosahexaenoic acid in the treatment of male infertility

Literature review is devoted to the analysis of modern data on the use of docosahexaenoic acid in the treatment of male infertility. A brief description of modern ideas about the possible causes of male infertility (a disturbance of function of the cell membrane and genetic damage of sperm) was conducted. The data on the anti-inflammatory properties of omega-3 polyunsaturated fatty acids are described in detail. The bioavailability of docosahexaenoic acid and the choice of drugs containing it for the treatment of male infertility are discussed. Increasing the content of polyunsaturated fatty acids, in particular docosahexaenoic acid, in the sperm membrane was associated with higher ejaculate quality. Therapy with the use of these substances led to the improvement of standard indicators of semen and a decrease in the proportion of sperm with fragmented DNA.

Histomorphology, Sperm Quality and Hormonal Profile in Adult Male Sprague-Dawley Rats following administration of aqueous crude Extract of Solanum nigrum by gastric gavage

Objective

The present study focused on histomorphology, sperm quality, hormonal profile and hematological parameters in adult male Sprague-Dawley rats following the administration of aqueous crude extract of Solanum nigrum by gastric gavage.

Methods

Fourty healthy male adult (12-14 weeks old) Sprague-Dawley rats weighing 200-220g were randomly divided into four groups (A,B,C and D) of ten (n=10) rats each. Group A which served as control were given distilled water 2ml/kg b.wt each, daily for 28 days. Group B, C and D rats were administered 100, 300 and 500mg/kg b.wt each daily respectively for 28 days. The extract was saved with LD₅₀ >5000mg/Kg. Sperm counts, percentage motility, morphology and percentage live sperm, hormonal profile and hematological parameter were quantified; testis, epididymal and general body weights were measured using a weighing scale. The extract was administered once daily for six days within a week via oral gavage. After the last administration, all rats were sacrificed by cervical dislocation, the testis were harvested and fixed in Bouin‘s fluid for histology processing.

Results

Our results revealed an increase in sperm counts, percentage of motility, morphology and percentage of live sperm, blood level of follicle stimulating hormone, Luteinizing hormone and testosterone, hematological parameters, testis, epididymal and general body weights across the groups in a dose-depentant manner. The testis histoarchtecture showed normal cellular composition in their germinal epithelium, with sperm cells in the lumen and a normal interstitium.

Conclusion

This experiment revealed that aqueous extract of Solanum nigrum bears profertility properties which may be beneficial to those who consume it.

The effects of oral antioxidants on the semen of men with idiopathic oligoasthenoteratozoospermia

It has been estimated that approximately 15% of reproductive-age couples suffer from infertility. Male factors contribute to almost half of infertility cases, and in many patients the underlying cause of oligoasthenoteratozoospermia is unknown. Accumulating evidence suggests that oxidative stress plays a role as a contributing factor to male infertility, and reactive oxygen species have been shown to impair sperm function and motility and to damage sperm membrane and DNA. Therefore, this review explored the evidence provided by studies published from 2002 to 2017 on the impact of oral antioxidants (vitamin C, vitamin E, L-carnitine, coenzyme Q10, zinc, selenium, and pentoxifylline) on seminal fluid parameters in men with idiopathic oligoasthenoteratozoospermia. Most of the studies were randomized controlled studies that investigated the effect of single or combined antioxidants and reported improvements in at least one semen parameter. The most noteworthy effect that was found was that the use of multiple antioxidants increased sperm motility and concentration. Nonetheless, there is a lack of agreement on the dose, the duration of treatment, and whether individual or combined oral antioxidants should be used. Therefore, the current review provides evidence supporting the use of oral antioxidants in the treatment of infertile men with idiopathic oligoasthenoteratozoospermia.

Lower dietary n-6 : n-3 ratio and high-dose vitamin E supplementation improve sperm morphology and oxidative stress in boars

A 2×2 factorial experiment (10 boars per treatment) was conducted for 16 weeks to evaluate the effects of the dietary n-6:n-3 ratio (14:1 vs 6:1) and vitamin E (200 vs 400mg kg^-1) on boar sperm morphology and oxidative stress. Sperm mitochondrial membrane potential (MMP), reactive oxygen species (ROS), DNA damage (8-hydroxydeoxyguanosine; 8-OHdG), seminal lipoperoxidation (malondialdehyde; MDA) and antioxidant capacity in the serum, spermatozoa and seminal plasma were assessed as indicators of oxidative stress. Sperm production was similar among groups but increased (P<0.05) throughout the 16 weeks of the study. Although sperm α-tocopherol content, ROS and seminal MDA did not differ between the two dietary n-6:n-3 ratio treatments, enhanced antioxidant enzyme activity and MMP, but decreased 8-OHdG, were found in spermatozoa from boars consuming the 6:1 diet. The diet with the 6:1 ratio positively affected sperm morphology at Weeks 12 and 16 (P<0.05). The α-tocopherol content and antioxidant capacity increased in boars with increasing levels of vitamin E supplementation. Compared with low-dose vitamin E, high-dose vitamin E supplementation improved sperm morphology. Overall, the results indicate that an n-6:n-3 ratio of 6:1 and 400 mg/kg vitamin E have beneficial effects on sperm morphology by improving antioxidative stress.

Protective potential of royal jelly against cadmium-induced infertility in male rats

This study aimed to investigate the protective potential of Royal jelly (RJ) against cadmium (Cd)-induced testicular dysfunction in rats. Thirty-five adult male Wistar rats were assigned into five groups. G I; (control) injected intraperitoneally with saline, G II injected intraperitoneally with a single dose of CdCl₂ (1 mg/kg BW), G III received RJ (100 mg/kg BW/day) orally, G IV was pre-treated with RJ for 1 week then, treated with CdCl₂ , and G V was co-treated with RJ and CdCl₂ . After day 56, serum and tissue samples were collected and analysed. The results showed decreased serum testosterone, luteinising hormone (LH), follicle-stimulating hormone (FSH), superoxide dismutase, glutathione reductase, sperm motility and count while increased malondialdehyde, nitric oxide, tumour necrosis factor-α (TNF-α) and sperm abnormalities, along with a severely damaged seminiferous tubules epithelium with cytoplasmic and nuclear disruptions following Cd toxicity. Additionally, Cd stimulated testicular mRNA expression of TNF-α while inhibited those of steroidogenic acute regulatory protein, cytochrome P450 cholesterol side chain cleavage enzyme androgen binding protein, FSH-receptor, LH-receptor, androgen receptor, 3β-hydroxysteroid dehydrogenase (HSD), 17β-HSD, and cytochrome P450 17A1. These negative alterations of cadmium were greatly reduced by RJ treatment. This study concluded that RJ protects against Cd-induced testicular toxicity.

Increased F2-Isoprostane Levels in Semen and Immunolocalization of the 8-Iso Prostaglandin F2α in Spermatozoa from Infertile Patients with Varicocele

Polyunsaturated fatty acid damages lead to alterations in sperm function. This study aimed to investigate the involvement of F₂-isoprostanes (F₂-IsoPs), oxidized lipid products from arachidonic acid, in sperm quality impairment. For this purpose, F₂-IsoP levels in semen and F₂-IsoP localization in spermatozoa were explored in infertile subjects affected by idiopathic infertility or varicocele, as well as in fertile men. As compared to fertile men, in the idiopathic infertility and varicocele groups, sperm concentration, motility, morphology, viability, and fertility index were significantly lower and the mean scores concerning sperm apoptosis, necrosis, and immaturity were significantly higher. The idiopathic infertile group showed a reduction in sperm motility and fertility index, as well as an increase of apoptosis and necrosis percentages, in comparison to the varicocele group. The varicocele group showed the highest levels of F₂-IsoPs, a significant increase of sperm immaturity, and a significant correlation between F₂-IsoP levels and sperm immaturity. 8-Iso Prostaglandin F_2α, biomarker of in vivo F₂-IsoP, was clearly localized in sperm midpiece and cytoplasmic residues. Data show that F₂-IsoP formation is relevant in semen and sperm from infertile patients with varicocele and high percentage of immaturity, suggesting that a correct fatty acid integrity is needed for sperm maturation.

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

Objective

To explore the current evidence concerning the effect of oral antioxidant supplementation on various male fertility outcomes, as antioxidants are widely available compounds that are commonly used for the treatment of male infertility.

Materials and methods

PubMed, Medline and Cochrane electronic databases were searched according to a modified Preferred Reporting Items for Systemic Reviews and Meta-Analyses (PRISMA) guidelines looking for studies investigating the effect of antioxidant therapy on infertile men. The studies were explored looking for antioxidants: (i) types and doses; (ii) mechanism of action and rationale for use; and (iii) effect on the different outcome measures reported.

Results

In all, 26 studies reported a significant positive effect of antioxidant therapy on basic semen parameters, advanced sperm function, outcomes of assisted reproductive therapy, and live-birth rate. Vitamin E, vitamin C, carnitines, N-acetyl cysteine, co-enzyme Q10, zinc, selenium, folic acid and lycopene were most commonly used. The vitamins’ mechanism of action and reported doses is presented in Table 1, Table 2.

Conclusion

Antioxidants generally have a favourable effect on male fertility. Further studies are needed to identify the optimal antioxidant regimen that can be used safely and efficiently in clinical practice.

Dietary patterns and semen quality: a systematic review and meta-analysis of observational studies

A number of studies have examined the association between dietary patterns and semen quality, but the findings have been inconclusive. Herein, we conducted a systematic review and meta-analysis of observational studies to assess the association between dietary patterns and semen quality. PubMed, Cochrane library, Science direct, Scopus, Google Scholar, and ISI web of science databases were searched up to August 2016 for observational studies assessing the association between common dietary patterns and sperm quality markers. Data were pooled by the generic inverse variance method with random effects and expressed as mean differences with 95% confidence intervals (CIs). Heterogeneity was assessed (Cochrane Q-statistic) and quantified (I² -statistic). The Newcastle-Ottawa Scale assessed study quality. Six eligible studies, involving 8207 participants, were included in our systematic review and meta-analysis. The pooled mean difference of sperm concentration for the healthy dietary pattern versus unhealthy dietary pattern intake was mean difference: 0.66; 95% CI, 0.305-1.016; p < 0.001. In comparison with those who had the highest adherence to healthy dietary pattern, individuals in the lowest adherence had significantly lower level of sperm concentration. However, no significant association was seen between eating patterns and other semen quality. Healthy dietary pattern seems to be associated with elevated sperm concentration level. Further longitudinal studies are needed to clarify this relationship.

Does sperm quality and DNA integrity differ in cryopreserved semen samples from young, adult, and aged Nellore bulls?

Background

In humans, it is now well documented that rising paternal age is correlated with decreased sperm DNA integrity and embryonic developmental failures. On the other side of the coin, it is also reported that very young fathers such as teenagers carry an increased risk of adverse birth outcomes. These observations suggest that, at least in humans, there is an age window for optimal sperm DNA integrity. In bovine, little is known about sperm DNA quality in young bulls and how it evolves with age. This study aimed to fill in this gap as it may be of importance for the bovine industry to know when exactly a bull is an optimal performer for reproductive programs.

Methods

Forty Nellore bulls were divided into three age groups: 1.8 to 2 years – young bulls; 3.5 to 7 years – adult bulls; and 8 to 14.3 years – aged bulls. Three ejaculates were collected from each bull, cryopreserved and evaluated for various parameters including: computer-assisted sperm analysis (CASA), plasma membrane and acrosome integrity, mitochondrial potential, sperm nuclear protamination, DNA oxidative damage, and Sperm Chromatin Structure Assay (SCSA).

Results

We report here that young bulls presented superior values for motility, plasma and acrosomal membrane integrity, and high mitochondrial potential. However, they also presented higher values for sperm morphological abnormalities compared to adult and aged animal groups (p < 0.05). In addition, young bulls exhibited more defective protamination than older animals did. The oldest bulls showed more nuclear oxidative damage than the younger groups of bulls while both the young and aged groups were found more susceptible to DNA denaturation as revealed with the SCSA test (p < 0.05).

Conclusion

These results indicate that young bulls spermatozoa best survived the freezing procedure, followed by adult and aged bulls. However, young and aged bulls were found to be more susceptible to DNA damage, respectively caused by protamine deficiency and oxidation. Therefore, although young bulls have correct semen parameters according to classical evaluation, our results indicate that they may show some structural nuclear immaturity.

Association of decreased spermatozoa omega-3 fatty acid levels and increased oxidative DNA damage with varicocele in infertile men: a case control study

Varicocele is commonly associated with male infertility because it impairs normal sperm morphology and activity. Polyunsaturated fatty acids (PUFA) are important determinants of sperm cell structure and function, but their relationship with varicocele remains unclear. The aim of the present study was to investigate the PUFA composition in spermatozoa of infertile men with varicocele and to evaluate the potential relationship between PUFA and varicocele. This case control study recruited 92 infertile men with varicocele, 99 infertile men without varicocele and 95 fertile male control subjects. Semen morphology and activity parameters were assessed and seminal plasma 8-hydroxy-2-deoxyguanosine (8-OHdG) content was determined by ELISA. Sperm concentrations of omega-3 and omega-6 fatty acids were measured by gas chromatography. Infertile men with varicocele had lower concentrations of omega-3 PUFA, higher omega-6:omega-3 PUFA ratios and greater oxidative DNA damage in spermatozoa compared with infertile men without varicocele and normal subjects. The degree of varicocele and DNA damage was associated with decreased omega-3 PUFA concentrations and semen quality in infertile men with varicocele. The findings suggest that omega-3 PUFA deficiency could be implicated in varicocele-associated infertility, and highlight the need for intervention trials to test the usefulness of omega-3 supplementation in reducing sperm abnormalities in infertile men with varicocele.

Supplementing oregano essential oil to boar diet with strengthened fish oil: Effects on semen antioxidant status and semen quality parameters

Previous research has shown benefits of dietary fish oil supplementation on semen quality of boars. However, little is known about how antioxidant protects lipid peroxidation on spermatozoa from n-3 polyunsaturated fatty acid (PUFA) addition. This study evaluated the effect of oregano essential oil (OEO) supplementation on semen antioxidant status and semen quality in boars fed a diet enriched with fish oil. Thirty-four mature boars of proven fertility, received daily 2.5 kg basal diet top-dressed with 45 g soybean oil and 15 g fish oil to meet the n-3 PUFA requirement of spermatozoa, randomly allocated to one of four groups supplemented with 100 mg α-tocopheryl acetate kg^-1 (control), or 250 or 500 or 750 mg OEO kg^-1 for 16 weeks. Semen was collected at weeks 0, 8, 12 and 16 for measurements of sperm production, motion characteristics, sperm α-tocopherol content, antioxidant enzyme activities, reactive oxygen species (ROS), DNA damage (8-hydroxydeoxyguanosine, 8-OHdG), lipoperoxidation (malondialdehyde, MDA) and seminal total antioxidant capacity (TAC). Sperm production and motion characteristics were similar (p > .05) among groups throughout the experimental week 16, but increased (p < .01) with experimental week. Although higher α-tocopherol content and superoxide dismutase (SOD) activities were in OEO group spermatozoa, feeding diet with 500 mg/kg OEO resulted in elevation in seminal TAC, decrease in sperm ROS, MDA and 8-OHdG than control group (p < .05). Overall, these results support the view that oregano essential oil has a positive effect on antioxidant capacity in boar when used fish oil.

Conservative Nonhormonal Options for the Treatment of Male Infertility: Antibiotics, Anti-Inflammatory Drugs, and Antioxidants

The nonhormonal medical treatment can be divided into empirical, when the cause has not been identified, and nonempirical, if the pathogenic mechanism causing male infertility can be solved or ameliorated. The empirical nonhormonal medical treatment has been proposed for patients with idiopathic or noncurable oligoasthenoteratozoospermia and for normozoospermic infertile patients. Anti-inflammatory, fibrinolytic, and antioxidant compounds, oligo elements, and vitamin supplementation may be prescribed. Infection, inflammation, and/or increased oxidative stress often require a specific treatment with antibiotics, anti-inflammatory drugs, and/or antioxidants. Combined therapies can contribute to improve sperm quality.