Role of oxidants in male infertility: rationale, significance, and treatment

Ellagic acid mitigates heat-induced testicular detriment in a mouse model

Heat stress has been shown to have a detrimental impact on testicular activity and spermatogenesis. Ellagic acid is a plant-derived organic compound that has a variety of biological functions. Thus, it is believed that ellagic acid may improve heat-stressed testicular dysfunction. There has been no research on the impact of ellagic acid on heat-stressed testicular dysfunction. The mice were divided into 4 groups. The first group was the normal control group (CN), and the second received heat stress (HS) by submerging the lower body for 15 min in a water bath with a thermostatically controlled temperature kept at 43°C (HS), and the third and fourth groups were subjected to heat-stress similar to group two and given two different dosages of ellagic acid (5 mg/kg (EH5) and 50 mg/kg (EH50) for 14 days. Ellagic acid at a dose of 50 mg/kg improved the level of circulating testosterone (increased 3βHSD) and decreases the oxidative stress. The testicular and epididymal architecture along with sperm parameters also showed improvement. Ellagic acid treatment significantly increases the germ cell proliferation (GCNA, BrdU staining) and Bcl2 expression and decreases active caspase 3 expression. Heat stress downregulated the expression of AR, ER-α and ER-β, and treatment with ellagic acid increased the expression of ER-α and ER-β markers in the 50 mg/kg treatment group. Thus, our finding suggests that ellagic acid ameliorates heat-induced testicular impairment through modulating testosterone synthesis, germ cell proliferation, and oxidative stress. These effects could be manifested by regulating androgen and estrogen receptors. However, the two doses showed differential effects of some parameters, which require further investigation.

The Role of Chlorella vulgaris in Attenuating Infertility Induced by Cadmium Chloride via Suppressing Oxidative Stress and Modulating Spermatogenesis and Steroidogenesis in Male Rats

Cadmium (Cd) is an environmental pollutant known as endocrine disruptor . Cd has been reported to induce perturbations of the testicular functions and the subsequent decline of the male fertility of both animals and humans. Chlorella vulgaris (ChV) a species of green microalga has been reported to have multiple beneficial activities such as anti-inflammatory, antioxidant, and antiapoptotic effects. Thus, this work was conducted to declare the benefits of Chlorella vulgaris (ChV) (500 mg/kg doses) against cadmium chloride CdCl2 (2 mg/kg doses) toxicity on the main and accessory reproductive organs' weight, structure, and function of male rats. Briefly, 40 adult male rats in 4 groups (n = 10) were used as follows; control, ChV, CdCl2, and CdCl2+ChV. (i) The 1st group was kept as control fed on pellet chow and water ad libitum. (ii) The second group is Chlorella vulgaris (ChV) group fed with C. vulgaris alga for 10 days (500 mg/kg BW). (iii) The third group was administrated CdCl2 (2mg/kg BW) via subcutaneous injection (S/C) daily for 10 days. (iv) The fourth group administered both CdCl2 and ChV with the abovementioned doses daily for successive 10 days. Our observations declared that cadmium exhibited an adverse influence on the testes and prostate gland architecture indicated by seminiferous tubule destruction, testicular edema, degeneration of Leydig cells, and prostate acini damage. All together affect the epididymal semen quality and quantity including sperm viability, motility, and count. Interestingly, ChV could restore the testicular architecture and spermatozoa regeneration accompanied by semen quality improvement and increased reproductive hormones including testosterone. On the other side, ChV suppresses reactive oxygen species (ROS) formation via enhancement the antioxidant-related genes in the testicular tissue including SOD, CAT, GSH, and MDA and maintaining spermatocyte survival via suppression of apoptotic related genes including caspase3 and activating steroidogenic related genes including StAR and HSD17β3 in the cadmium-treated testes. In this study, ChV could enhance male fertility under normal or stressful conditions and ameliorate the adverse effects of hazardous heavy metals that are widely distributed in our environment.

Effects of environmental temperature extremes exposure on sperm quality - evidence from a prospective cohort study in Anhui Province, China

Extreme weather is becoming more frequent due to drastic changes in the climate. Despite this, the body of research focused on the association between temperature extreme events and sperm quality remains sparse. In this study, we elucidate the impact of exposure to environmental temperature extremes on sperm quality. Data for this investigation were derived from the Anhui Prospective Assisted Reproduction Cohort, encompassing the period from 2015 to 2020. Parameters such as sperm concentration, total sperm count, total motility, progressive motility, total motile sperm count, and progressive motile sperm count were quantified from semen samples. We assessed the exposure of participants to temperature extremes during the 0-90 days prior to sampling. This investigation encompassed 15,112 participants, yielding 28,267 semen samples. Our research findings indicate that exposure to low temperature extreme for three consecutive days (at the first percentile threshold) has a detrimental correlation with sperm count parameters and concentration. Similar trends were observed with the second percentile threshold, where significant adverse effects typically manifested after a four-day exposure sequence. Analysis of high temperature extreme showed that exposure at the 98th percentile had adverse effects on all six sperm quality parameters, and the sperm count parameter was particularly sensitive to high temperature, showing significant results immediately after three days of exposure. When considering even more temperature extreme (99th percentile), the negative consequences were more pronounced on the sperm count parameter. Additionally, progressive motility showed a stronger negative response. In summary, parameters associated with sperm count are particularly vulnerable to temperature extremes exposure. Exposure to high temperature extremes environments may also be associated with a decrease in sperm concentration and vitality. The findings of this study suggest that male population should pay attention to avoid exposure to temperature extreme environment, which has important significance for improving the quality of human fertility.

Semen proteome and transcriptome of the endangered black-footed ferret (Mustela nigripes) show association with the environment and fertility outcome

The ex situ population of the endangered black-footed ferret (Mustela nigripes) has been experiencing declines in reproductive success over the past 30 years of human-managed care. A potential cause may be environmental-dependent inbreeding depression with diet being one of the contributing factors since ferrets are not fed their natural diet of prairie dogs. Here, we generated and analyzed semen proteome and transcriptome data from both wild and ex situ ferrets maintained on various diets. We identified 1757 proteins across all samples, with 149 proteins unique to the semen of wild ferrets and forming a ribosomal predicted protein-protein interaction cluster. Wild ferrets also differed from ex situ ferrets in their transcriptomic profile, showing enrichment in ribosomal RNA processing and potassium ion transport. Successful fertility outcomes documented for ex situ ferrets showed the strongest association with the semen transcriptome, with enrichment in genes involved in translation initiation and focal adhesion. Fertility also synergized with the effect of diet on differentially expressed transcriptomes, mainly affecting genes enriched in mitochondrial function. Our data and functional networks are important for understanding the causes and mechanisms of declining fertility in the ex situ ferret population and can be used as a resource for future conservation efforts.

Leptin effects: focusing on the relationship between obesity and male infertility

The human male infertility has several causes interconnected to improper lifestyles such as smoking, sedentarism, environmental factors, toxins accumulation and energy imbalances. All these factors contribute to the obesity accompanied metabolic syndrome and hormonal alterations in the leptin-ghrelin axis. The leptin (Lep) has many pleiotropic effects in several biological systems, directly on the peripheral tissues or through the central nervous system. Many studies suggest that Lep is a key player in gonadal functions beside its documented role in reproductive regulation; however, further investigations are still necessary to elucidate all the molecular pathways involved in these mechanisms. Keeping into account that increased Lep levels in obese men are positively correlated with altered sperm parameters and testicular oxidative stress, evidence refers to Lep as a potential link between obesity and male infertility. This review represents an updated version on the concept of the Lep roles in mediating the male reproductive functions in obese patients.

Discriminant Analysis and Data Mining CHAID Decision Tree as Tools to Evaluate the Buffering Effect of Hydroxytyrosol on Reactive Oxygen Species in Rooster Sperm Cryopreservation

Sperm cryopreservation is effective in safeguarding genetic biodiversity in avian species. However, during this process, spermatozoa are very susceptible to plasma membrane peroxidation in the presence of high concentrations of reactive oxygen species (ROS). To mitigate this effect, the addition of exogenous antioxidants, such as hydroxytyrosol (3,4-dihydroxyphenylethanol; HT), an antioxidant derived from olive oil, to the cryopreservation sperm diluent, could be useful. To verify this, a cryopreservation diluent was supplemented with different concentrations (0 μg/mL, 50 μg/mL, 100 μg/mL, and 150 μg/mL) of HT. For this, semen was collected in 10 replicates from 16 roosters of the Utrerana avian breed, and a pool was prepared with the optimum quality ejaculates in each replicate. After cryopreservation, spermatozoa were thawed and different in vitro semen quality parameters were evaluated. A discriminant canonical analysis (DCA) was carried out and revealed that total motility (TM; Lambda = 0.301, F = 26,173), hypo-osmotic swelling test (HOST; Lambda = 0.338, F = 22,065), and amplitude of lateral head displacement (ALH, Lambda = 0.442; F = 14,180) were the variables with the highest discriminant power. Finally, a chi-squared automatic interaction detection (CHAID) decision tree (DT) was performed excluding fresh semen samples and ROS was found to be the most valuable variable to discriminate between the different established freezing groups. Samples in the absence of HT or with low concentrations of this antioxidant showed less desirable ROS values in cryopreserved rooster semen. The present study could lead to the improvement of cryopreservation techniques for the genetic material of local poultry breeds and optimize the conservation programs of endangered native avian breeds.

Oxidative stress-induced apoptosis and autophagy: Balancing the contrary forces in spermatogenesis

Spermatogenesis is a complex process in the testis and is a cornerstone of male infertility. The abundance of unsaturated fatty acid and high cell division rate make male germs cells prone to DNA deterioration. ROS-mediated oxidative stress triggers DNA damage, autophagy, and apoptosis in male germ cells, which are critical causative factors that lead to male infertility. The complex connection and molecular crosstalk between apoptosis and autophagy is seen at multifaceted levels that interconnect the signaling pathways of these two processes. Multilevel interaction between apoptosis and autophagy is a seamless state of survival and death in response to various stressors. Interaction between multiple genes and proteins such as the mTor signaling pathway, Atg12 proteins, and the death adapter proteins, such as Beclin 1, p53, and Bcl-2 family proteins, validates such a link between these two phenomena. Testicular cells being epigenetically different from somatic cells, undergo numerous significant epigenetic transitions, and ROS modulates the epigenetic framework of mature sperm. Epigenetic deregulation of apoptosis and autophagy under oxidative stress conditions can cause sperm cell damage. The current review recapitulates the current role of prevailing stressors that generate oxidative stress leading to the induction of apoptosis and autophagy in the male reproductive system. Considering the pathophysiological consequences of ROS-mediated apoptosis and autophagy, a combinatorial approach, including apoptosis inhibition and autophagy activation, a therapeutic strategy to treat male idiopathic infertility. Understanding the crosslink between apoptosis and autophagy under stress conditions in male germ cells may play an essential role in developing therapeutic strategies to treat infertility.

Nanoscale MRI for Selective Labeling and Localized Free Radical Measurements in the Acrosomes of Single Sperm Cells

Free radicals play a major role in sperm development, including maturation and fertilization, but they are also linked to infertility. Since they are short-lived and reactive, they are challenging to detect with state of the art methodologies. Thus, many details surrounding their role remain unknown. One unknown factor is the source of radicals that plays a role in the sperm maturation process. Two alternative sources have been postulated: First, the NADPH-oxidase system embedded in the plasma membrane (NOX5) and second, the NADH-dependent oxidoreductase of mitochondria. Due to a lack of localized measurements, the relative contribution of each source for capacitation remains unknown. To answer this question, we use a technique called diamond magnetometry, which allows nanoscale MRI to perform localized free radical detection. With this tool, we were able to quantify radical formation in the acrosome of sperm heads. This allowed us to quantify radical formation locally in real time during capacitation. We further investigated how different inhibitors or triggers alter the radical generation. We were able to identify NOX5 as the prominent source of radical generation in capacitation while the NADH-dependent oxidoreductase of mitochondria seems to play a smaller role.

Deciphering the Nexus Between Oxidative Stress and Spermatogenesis: A Compendious Overview

Oxidative stress (OS) and reactive oxygen species (ROS) are one of the main reasons for the multifactorial concern - male infertility. ROS are active components of cellular metabolism that are intrinsic to cellular functioning and are present at minimal and unreactive levels in normal cells. They are an integral component of the sperm developmental physiology, capacitation, and function. As said "anything in excess is poison," so is the case with ROS. These, when produced in excess to the antioxidants present in the seminal plasma, cause multiple malformations during the process of spermatogenesis such as lipid peroxidation, interfere with capacitation, sperm DNA fragmentation and damage to the membrane of the sperm which in turn reduces the motility of the sperm and its ability to fuse with the oocyte. Exposure of spermatozoa to oxidative stress is a major causative agent of male infertility. Thus, a delicate balance between the beneficial and detrimental effects of ROS for proper functions is of utter importance. In this chapter, the influence of ROS in OS which is a key player in male infertility along with the diagnosis, available treatment, and prevention of extensive ROS buildup within the spermatozoa are highlighted.

Vitamin B12 ameliorate Tramadol-induced oxidative stress, endocrine imbalance, apoptosis and NO/iNOS/NF-κB expression in Sprague Dawley rats through regulatory mechanism in the pituitary-gonadal axis

This study aimed at the effect of vitamin B₁₂ (VB₁₂) on tramadol (TRM) induced pituitary-gonadal Axis toxicity. Thirty-two (32) adult male rats were randomized into four groups of eight (n = 8) rats each. Group A served as control was given 1 mL normal saline, group B received 50 mg /kg bwt TRM, group C received 0.5 mg/kg bwt VB₁₂ and group D received 50 mg /kg bwt TRM and 0.5 mg/kg bwt VB₁₂ through gastric gavage daily for 8 weeks. Parameters tested include sperm parameter, male reproductive hormone, testicular histology, glucose, lactate dehydrogenase (LDH), acid phosphate (ACP), and alkaline phosphate (ALP) activity, steroidogenic protein, cytochrome P450 A1, nitric oxide (NO), inducible nitric oxide synthase (iNOS), interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), nuclear factor- kappa B (NF-κB), oxidative and antioxidant makers. Tramadol significantly decreases sperm quality, hormone, steroidogenic protein, cytochrome P450 A1, ACP, ALP, and increases glucose, LDH, oxidative stress, mtTFA, and UCP2, p53 expression, NO, iNOS, NF-κB, IL-1β, IL-6, TNF-α, and caspase-3 activity. Degenerative alterations of the testes' and pituitary architecture and perturbation of spermatogenesis were observed in TRM-treated rats. The intervention of VB₁₂ downregulated testicular oxidative stress, inflammatory markers, glucose, lactate, LDH, p53, caspase-3, mtTFA, and UCP2. And upregulate antioxidant, sperm quality, hormone, and spermatogenic cells. Vitamin B₁₂ exhibited mitigation against TRM-induced testicular dysfunction via its antioxidant, anti-inflammatory and anti-apoptotic effects.

Bacterial Infections Affect Male Fertility: A Focus on the Oxidative Stress-Autophagy Axis

Numerous factors trigger male infertility, including lifestyle, the environment, health, medical resources and pathogenic microorganism infections. Bacterial infections of the male reproductive system can cause various reproductive diseases. Several male reproductive organs, such as the testicles, have unique immune functions that protect the germ cells from damage. In the reproductive system, immune cells can recognize the pathogen-associated molecular patterns carried by pathogenic microorganisms and activate the host's innate immune response. Furthermore, bacterial infections can lead to oxidative stress through multiple signaling pathways. Many studies have revealed that oxidative stress serves dual functions: moderate oxidative stress can help clear the invaders and maintain sperm motility, but excessive oxidative stress will induce host damage. Additionally, oxidative stress is always accompanied by autophagy which can also help maintain host homeostasis. Male reproductive system homeostasis disequilibrium can cause inflammation of the genitourinary system, influence spermatogenesis, and even lead to infertility. Here, we focus on the effect of oxidative stress and autophagy on bacterial infection in the male reproductive system, and we also explore the crosslink between oxidative stress and autophagy during this process.

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.

In vitro effect of ferrous sulphate on bovine spermatozoa motility parameters, viability and Annexin V-labeled membrane changes

The aim of this study was to assess the dose- and time-dependent in vitro effects of ferrous sulphate (FeSO₄.7H₂O) on the motility parameters, viability, structural and functional activity of bovine spermatozoa. Spermatozoa motility parameters were determined after exposure to concentrations (3.90, 7.80, 15.60, 31.20, 62.50, 125, 250, 500 and 1000 μM) of FeSO₄.7H₂O using the SpermVision^TM CASA (Computer Assisted Semen Analyzer) system in different time periods. Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay, and the Annexin V-Fluos was applied to detect the membrane integrity of spermatozoa. The initial spermatozoa motility showed increased average values at all experimental concentrations compared to the control group (culture medium without FeSO₄.7H₂O). After 2 h, FeSO₄.7H₂O stimulated the overall percentage of spermatozoa motility at the concentrations of ≤ 125 μM. However, experimental administration of 250 μM of FeSO₄.7H₂O significantly (P < 0.001) decreased the spermatozoa motility but had no negative effect on the cell viability (P < 0.05) (Time 2 h). The lowest viability was noted after the addition of ≥ 500 μM of FeSO₄.7H₂O (P < 0.001). The concentrations of ≤ 62.50 μM of FeSO₄.7H₂O markedly stimulated (P < 0.001) spermatozoa activity after 24 h of exposure, while at high concentrations of ≥ 500 μM of FeSO₄.7H₂O the overall percentage of spermatozoa motility was significantly inhibited (P < 0.001) and it elicited cytotoxic action. Fluorescence analysis confirmed that spermatozoa incubated with higher concentrations (≥ 500 μM) of FeSO₄.7H₂O displayed apoptotic changes, as detected in head membrane (acrosomal part) and mitochondrial portion of spermatozoa. Moreover, the highest concentration and the longest time of exposure (1000 μM of FeSO₄.7H₂O; Time 6 h) induced even necrotic alterations to spermatozoa. These results suggest that high concentrations of FeSO₄.7H₂O are able to induce toxic effects on the structure and function of spermatozoa, while low concentrations may have the positive effect on the fertilization potential of spermatozoa.

Reactive oxygen species (ROS): utilizing injectable antioxidative hydrogels and ROS-producing therapies to manage the double-edged sword

Reactive oxygen species (ROS) are generated in cellular metabolism and are essential for cellular signalling networks and physiological functions. However, the functions of ROS are 'double-edged swords' to living systems that have a fragile redox balance between ROS generation and elimination. A modest increase of ROS leads to enhanced cell proliferation, survival and benign immune responses, whereas ROS stress that overwhelms the cellular antioxidant capacity can damage nucleic acids, proteins and lipids, resulting in oncogenic mutations and cell death. ROS are therefore involved in many pathological conditions. On the other hand, ROS present selective toxicity and have been utilised against cancer and pathogens, thus also acting as a double-edged sword in the healthcare field. Injectable antioxidative hydrogels are gel precursors that form hydrogel constructs in situ upon delivery in vivo to maintain an antioxidative capacity. These hydrogels have been developed to counter ROS-induced pathological conditions, with significant advantages of biocompatibility, excellent moldability, and minimally invasive delivery. The intrinsic, readily controllable ROS-scavenging ability of the functionalised hydrogels overcomes many drawbacks of small molecule antioxidants. This review summarises the roles of ROS under pathological conditions and describes the state-of-the-art of injectable antioxidative hydrogels. A particular emphasis is also given to current ROS-producing therapeutic interventions, enabling potential application of injectable antioxidant hydrogels to prevent the adverse effects of many cancer and infection treatments.

Seminal plasma metabolomics profiles following long (4-7 days) and short (2 h) sexual abstinence periods

OBJECTIVE

Metabolomic profiling of seminal plasma has been suggested as a possible approach for a fast and non-invasive male infertility evaluation diagnosis. However, metabolomics profiles in normozoospermic men have not been thoroughly investigated, and the influence of ejaculation-abstinence has not been described. To provide interim reference values and find associations between the metabolomics profiles of human seminal plasma and length of ejaculation-abstinence period in normozoospermic men.

STUDY DESIGN

Semen samples collected after long (4-7 days) and short abstinence (2 h) from 31 normozoospermic males were assessed for routine quality parameters before the seminal plasma was separated by centrifugation. Metabolomics profiles of the seminal plasma were then determined using untargeted Nuclear Magnetic Resonance Spectroscopy.

RESULTS

In total, 30 metabolites were identified. Pyruvate showed a higher concentration, while fructose, acetate, choline, methanol, N-acetylglucosamine, O-acetylcarnitine, uridine, and sn-glycero-3-phosphocoline showed lower concentrations in samples collected after short abstinence (vs. long). All metabolites showed lower absolute amounts (volume × concentration) following shorter abstinence. However, the lower sperm concentration in samples collected after short abstinence resulted in higher absolute amounts of pyruvate and taurine per spermatozoa: pyruvate 1.92 (1.12-3.87) vs. 1.29 (0.83-2.62) (P < 0.001) and taurine 0.58 (0.36-0.92) vs. 0.43 (0.28-0.95) (P < 0.05) ng/10⁶ spermatozoa. Simultaneously, there was a higher percentage of progressively motile spermatozoa in samples collected after the short abstinence.

CONCLUSION

The generally lower concentrations of seminal metabolites after short abstinence periods may be related to the shorter time available for secretion and collection of these metabolites by the accessory glands and the epididymides. The concomitant lower number of spermatozoa in the second ejaculate resulted in increased absolute amounts of pyruvate and taurine per spermatozoa, accompanied by increased spermatozoa motility in these samples. The simultaneous increase in percentages of motile spermatozoa and absolute amounts of pyruvate and taurine per spermatozoa after shorter abstinence might indicate that these two metabolites play a more critical role in sperm motility, which should be further investigated in future studies.

Bayesian Analysis of the Effects of Olive Oil-Derived Antioxidants on Cryopreserved Buck Sperm Parameters

The present study evaluates the effect of olive oil-derived antioxidants, hydroxytyrosol (HT) and 3,4-dihydroxyphenylglycol (DHPG), on cryopreserved caprine sperm using Bayesian inference of ANOVA. For this proposal, sperm was collected, pooled and diluted in freezing media supplemented with different concentrations of HT, DHPG and the mixture (MIX) of both antioxidants. Sperm motility, viability, acrosome integrity, mitochondrial status, and lipid peroxidation (LPO) were assessed in fresh and frozen-thawed sperm samples. The results provided evidence that HT at low concentrations improves sperm motility and viability, and reduces the LPO. Contrastingly, DHPG and MIX exert a positive effect by reducing LPO values as concentration increases. Additionally, mitochondrial potential was reduced when samples were supplemented with HT at low concentrations and mixture of both antioxidants. Conclusively, the addition of olive oil-derived antioxidants (HT at 10 µg/mL and DHPG at 30 µg/mL) implements a protective effect in cryopreserved buck sperm. Bayesian analysis alternatives offer new possibilities to determine the repercussion of antioxidants on sperm, both quantitatively and qualitatively.

Using hair cortisol analysis to understand the biological factors that affect black-footed ferret (Mustela nigripes) stress physiology

The black-footed ferret (Mustela nigripes) was driven to near extinction due to habitat loss and an introduced disease, sylvatic plague (Yersinia pestis). After 35 years of breeding in ex situ facilities, the black-footed ferret has been experiencing infertility with seminal traits declining in males and only about a third of breeding-aged females are whelping. Our goal was to use hair cortisol analysis to determine if the ex situ population was experiencing chronic stress that was affecting reproduction by comparing captive ferrets to wild individuals. Our specific objectives were to (i) compare hair cortisol concentrations (HCCs) between age classes (juveniles versus adults), (ii) compare the HCCs of in situ and across different ex situ facilities and (iii) determine the relationship between HCCs and reproductive success. Overall, wild juveniles had higher HCC than wild adults. Our generalized linear mixed model determined that the parameters that best predict HCC for adults were the interactions among sex, in situ versus ex situ facilities and season. During both seasons, wild females had higher HCCs compared to the ex situ females. During the breeding season, male HCCs across breeding facilities varied and males at the breeding facility with the largest ferret habitats had HCCs similar to wild males. At one breeding facility, HCC was higher in males that sired compared to those that did not sire. In conclusion, ex situ ferrets do not have higher HCC than wild individuals when controlling for season and ex situ habitat size, and ex situ males with higher HCC tended to sire. This suggests that HCC may be metabolically driven and/or that low HCC may be an indication of hypothalamus-pituitary-adrenal axis dysregulation and warrants further investigation both for laboratory validation and biological relevance.

Evaluation of quality and gene expression of goat embryos produced in vivo and in vitro after cryopreservation

In the present study, we aimed to identify morphological and molecular changes of in vivo and in vitro-produced goat embryos submitted to cryopreservation. In vivo embryos were recovered by transcervical technique from superovulated goats, whereas in vitro produced embryos were produced from ovaries collected at a slaughterhouse. Embryos were frozen by two-steps slow freezing method, which is defined as freezing to -32 °C followed by transfer to liquid nitrogen. Morphological evaluation of embryos was carried out by assessing blastocoel re-expansion rate and the total number of blastomeres. The expression profile of candidate genes related to thermal and oxidative stress, apoptosis, epigenetic, and implantation control was measured using RT-qPCR based SYBR Green system. In silico analyses were performed to identify conserved genes in goat species and protein-protein interaction networks were created. In vivo-produced embryos showed greater blastocoel re-expansion and more blastomere cells (P < 0.05). The expression level of CTP2 and HSP90 genes from in vitro cryopreserved embryos was higher than their in vivo counterparts. Unlikely, no significant difference was observed in the transcription level of SOD gene between groups. The high similarity of CPT2 and HSP90 proteins to their orthologs among mammals indicates that they share conserved functions. In summary, cryopreservation negatively affects the morphology and viability of goat embryos produced in vitro and changes the CPT2 and HSP90 gene expression likely in response to the in vitro production process.

In vitro effects of Capparis spinosa L. extract on human sperm function, DNA fragmentation, and oxidative stress

ETHNOPHARMACOLOGICAL RELEVANCE

Oxidative stress is one of the underlying causes of male infertility. Medicinal plants have many benefits for infertility treatment in men.

AIM OF THE STUDY

In the present study, we evaluated in vitro effects of Capparis spinosa leaf extract on human sperm function, DNA fragmentation, and oxidative stress.

MATERIALS AND METHODS

We conducted this study on the hydroalcoholic extract of C. spinosa. Polyphenol compounds and antioxidant effects of the leaf and fruit extract were determined by HPLC and DPPH method, respectively. Flavones and flavonols, total flavonoid, total phenolic content, tannin, and the total carbohydrate content were determined calorimetrically. Semen samples from 50 healthy men (20-45 years) were divided into control and experimental (15, 30, and 45 ppm of C. spinosa leaf extract) groups. Motility, viability, lipid peroxidation, and DNA fragmentation were evaluated 24 h after incubation.

RESULTS

The antioxidant effect of leaf extract was six times greater than fruit. Progressive and total motility of caper-treated groups (30 and 45 ppm) were crucially higher than the control group. Viability in all treatments was significantly higher than the control group. There was no significant difference in lipid peroxidation. DNA fragmentation in the caper-treated group (45 ppm) was significantly lower than the control group.

CONCLUSIONS

Our results suggest the potential positive in vitro effect of C. spinosa leaf extract on human sperm function. The use of C. spinosa leaf extract or its active metabolites in the sperm culture medium may be beneficial for maintaining motility, vitality, and sperm DNA. Since these effects were observed at very low concentrations of caper, other non-antioxidant mechanisms must be considered.

Can troxerutin pretreatment prevent testicular complications in prepubertal diabetic male rats?

OBJECTIVE

The vast majority of type 1 diabetes leads to a higher prevalence of reproductive system's impairments. Troxerutin has attracted much attention owing to its favorable properties, including antihyperglycemic, anti-inflammatory, and antiapoptotic effects. This investigation was proposed to evaluate whether pretreatment with troxerutin could prevent apoptosis-induced testicular disorders in prepubertal diabetic rats.

METHODS

Fifty prepubertal male Wistar rats were randomly allocated into five groups: control (C), troxerutin (TX), diabetic (D), diabetic+troxerutin (DTX), and diabetic+insulin (DI). Diabetes was induced by 55 mg/kg of streptozotocin applied intraperitoneally. In TX and DTX groups, 150 mg/kg troxerutin was administered by oral gavage. Diabetic rats in DI group received 2-4 U NPH insulin subcutaneously. Troxerutin and insulin treatments were begun immediately on the day of diabetes confirmation. After 30 days, the testicular lipid peroxidation and antioxidant activity, apoptosis process, and stereology as well as serum glucose and insulin levels were assessed.

RESULTS

The results showed that diabetes caused a significant increase in the blood glucose, the number of TUNEL positive cells and tubules, and the malondialdehyde level as well as a significant decrease in serum insulin level compared to controls. The stereological analysis also revealed various alterations in diabetic rats compared to controls. Troxerutin treatment improved these alterations compared to the diabetic group.

CONCLUSION

Troxerutin-pretreatment may play an essential role in the management of the type-1 diabetes-induced testicular disorders by decreasing blood glucose and modulating apoptosis.

Analysis of the Functional Aspects of Sperm and Testicular Oxidative Stress in Individuals Undergoing Metabolic Surgery

PURPOSE

Metabolic surgery is a recommended treatment for obese patients that results in BMI reduction; however, the observed impact of this therapy on male fertility is inconsistent. This research aimed to study the effects of BMI changes after metabolic surgery on seminal analysis, sex hormonal profile, sperm functional integrity, and the seminal plasma lipid peroxidation levels.

MATERIALS AND METHODS

A prospective study was performed in 15 patients for whom metabolic surgery was recommended. The patients were evaluated by the techniques proposed in this study before and after the surgical procedure for 12 months. In each analysis, the male sex hormonal profile, semen analysis, sperm functional integrity, and seminal lipid peroxidation levels were assessed.

RESULTS

The surgery resulted in BMI reduction and improvement in seminal characteristics and male sex hormone profile. The semen analysis showed increases in volume, sperm progressive motility, and in sperm morphology and a decrease in immotile sperms. Sperm mitochondrial activity and sperm DNA integrity were improved, and the levels of seminal lipid peroxidation were decreased. The hormonal profile showed lower levels of estradiol and highest levels of luteinizing hormone (LH), sex hormone-binding globulin (SHBG), and testosterone.

CONCLUSION

BMI changes resulting from this treatment and its metabolic consequences can be associated with changes in the male fertile potential, leading to an improvement in the seminal quality, male sex hormone profile, sperm functional aspects, and levels of seminal lipid peroxidation, thus decreasing the testicular oxidative stress.

The impact of reactive oxygen species in the development of cardiometabolic disorders: a review

Oxidative stress, an alteration in the balance between reactive oxygen species (ROS) generation and antioxidant buffering capacity, has been implicated in the pathogenesis of cardiometabolic disorders (CMD). At physiological levels, ROS functions as signalling mediators, regulates various physiological functions such as the growth, proliferation, and migration endothelial cells (EC) and smooth muscle cells (SMC); formation and development of new blood vessels; EC and SMC regulated death; vascular tone; host defence; and genomic stability. However, at excessive levels, it causes a deviation in the redox state, mediates the development of CMD. Multiple mechanisms account for the rise in the production of free radicals in the heart. These include mitochondrial dysfunction and uncoupling, increased fatty acid oxidation, exaggerated activity of nicotinamide adenine dinucleotide phosphate oxidase (NOX), reduced antioxidant capacity, and cardiac metabolic memory. The purpose of this study is to discuss the link between oxidative stress and the aetiopathogenesis of CMD and highlight associated mechanisms. Oxidative stress plays a vital role in the development of obesity and dyslipidaemia, insulin resistance and diabetes, hypertension via various mechanisms associated with ROS-led inflammatory response and endothelial dysfunction.

Impact of oxidative stress on semen parameters in normozoospermic infertile men: a case–control study

Background

Oxidative stress has been implicated in male infertility through decrease in sperm quality. However, men with normal semen parameters (normozoospermia) may be unable to fertilize their partners even when they have normal sperm function. Thus, they would be considered infertile. The purpose of this study was to investigate the role of oxidative stress in the pathogenesis of unexplained male infertility.

Methods

In this case–control study, infertile men with normozoospermia (n = 46) and fertile control group (n = 21) underwent seminal fluid analyses according to WHO 2010 criteria. Serum and seminal plasma levels of total antioxidant capacity (TAC), glutathione, malondialdehyde, uric acid and albumin were also measured using colorimetric methods.

Results

The level of total antioxidant capacity in both serum and seminal plasma was significantly lower in normozoospermic infertile men in comparison with fertile group (p < 0.0001). However, no significant differences were observed in serum and seminal plasma levels of glutathione, uric acid, albumin and malondialdehyde between infertile and fertile groups.

Conclusion

Low TAC level induces oxidative stress and consequently causes sperm dysfunction and male infertility. Estimation of TAC can be a useful tool in the diagnosis of male infertility. Antioxidant supplementation should be considered in the treatment of oxidative stress-induced male infertility.

Antioxidant pretreatment for male partner before ART for male factor subfertility: a randomized controlled trial

STUDY QUESTION

Does oral antioxidant pretreatment for the male partner improve clinical pregnancy rate in couples undergoing ART for male factor subfertility?

SUMMARY ANSWER

There was no significant difference in clinical pregnancy rate following oral antioxidant pretreatment for male partner in couples undergoing ART for male factor subfertility compared to no pretreatment.

WHAT IS KNOWN ALREADY

Damage to sperm mediated by reactive oxygen species (ROS) contributes significantly to male factor infertility. The ROS-related injury reduces fertilization potential and adversely affects the sperm DNA integrity. Antioxidants act as free radical scavengers to protect spermatozoa against ROS induced damage. During ART, use of sperms which have been exposed to ROS-mediated damage may affect the treatment outcome. Pretreatment with antioxidants may reduce the ROS-mediated sperm DNA damage. Currently, antioxidants are commonly prescribed to men who require ART for male factor subfertility but there is ambiguity regarding their role.

STUDY DESIGN SIZE DURATION

This was an open label, randomized controlled trial conducted at a tertiary level infertility clinic between February 2013 and October 2019. The trial included 200 subfertile couples who were undergoing ART treatment for male factor subfertility.

PARTICIPANTS/MATERIALS SETTING METHODS

Couples were randomized into treatment arm (n = 100) and control arm (n = 100). In the treatment arm, the male partner received oral antioxidants (Vitamin C, Vitamin E and Zinc) for 3 months just prior to the ART cycle. In the control arm, no antioxidant was given to the male partner. The primary outcome was clinical pregnancy rate, while live birth rate (LBR), miscarriage rate and changes in semen parameters were the secondary outcomes.

MAIN RESULTS AND THE ROLE OF CHANCE

Out of 200 women randomized, 135 underwent embryo transfer as per protocol. Following intention to treat analysis, no significant difference was noted in clinical pregnancy (36/100, 36% vs 26/100, 26%; odds ratio (OR) 1.60, 95% CI 0.87 to 2.93) and LBR (25/100, 25% vs 22/100, 22%; OR 1.18, 95% CI 0.61 to 2.27) between antioxidant and no pretreatment arms. The clinical pregnancy rate per embryo transfer was significantly higher following antioxidant pretreatment (35/64, 54.7% vs 26/71, 36.6%; OR 2.09, 95% CI 1.05 to 4.16) compared to no pretreatment. There was no significant difference in LBR per embryo transfer (25/64, 39.1%, vs 22/71, 31.0%; OR 1.43, 95% CI 0.70 to 2.91) after antioxidant pretreatment versus no pretreatment. The semen parameters of sperm concentration (median, interquartile range, IQR) (18.2, 8.6 to 37.5 vs 20.5, 8.0 to 52.5, million/ml; P = 0.97), motility (median, IQR) (34, 20 to 45 vs 31, 18 to 45%; P = 0.38) and morphology (mean ± SD) (2.0 ± 1.4 vs 2.2 ± 1.5%; P = 0.69) did not show any significant improvement after intake of antioxidant compared to no treatment, respectively.

LIMITATIONS REASONS FOR CAUTION

The objective assessment of sperm DNA damage was not carried out before and after the antioxidant pretreatment. Since the clinicians were aware of the group allotment, performance bias cannot be ruled out.

WIDER IMPLICATIONS OF THE FINDINGS

The current study did not show any significant difference in clinical pregnancy and LBR following antioxidant pretreatment for the male partner in couples undergoing ART for male subfertility. The findings need further validation in a larger placebo-controlled randomized trial.

STUDY FUNDING/COMPETING INTERESTS

This trial has been funded by Fluid Research grant of Christian Medical College, Vellore (internal funding). The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

CTRI/2013/02/003431.

TRIAL REGISTRATION DATE

26 February 2013.

DATE OF FIRST PATIENT’S ENROLMENT

11 February 2013.

Protective effect of naringenin against cadmium-induced testicular toxicity in male SD rats

This study aimed to investigate the effect of naringenin (Nar) on cadmium (Cd)-induced testicular toxicity. Twenty-four male Sprague-Dawley (SD) rats aged 5 weeks were used. Rats were administered with 0.9% NaCl (control group), CdCl₂ (2 mg/kg b.w. intraperitoneally), Nar (50 mg/kg b.w, orally), and CdCl₂ + Nar (2 mg/kg b.w intraperitoneally and 50 mg/kg b.w. orally, respectively) for 4 weeks. Results showed that body weight, relative testis weights, and sperm quality decreased in the Cd-treated group, and Cd accumulated in serum and testes. Pathological examination showed that Cd can cause testicular damage. Cd decreased the serum concentrations of gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone. It also decreased the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). Moreover, exposure to Cd resulted in decreased content of reduced glutathione (GSH) and total antioxidant capacity (T-AOC) concentrations, as well as increased malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) contents. Cd also provoked testis autophagy by upregulating the expression of the autophagy-related proteins P62 and LC3 II. However, the combined administration of Nar and Cd significantly attenuated the Cd-induced negative effects by increasing the body weight, relative testis weights, and sperm quality and by decreasing testicular damage. Simultaneous supplementation of Nar and Cd markedly restored the decreased levels of GnRH, FSH, LH, testosterone, GSH, and T-AOC and the activities of SOD, CAT, and GPx caused by Cd treatment. Nar further suppressed MDA and H₂O₂ production and protected the testes from Cd-induced autophagy by downregulating P62 and LC3 II expression. Therefore, Nar protected the testes from Cd-induced toxicity.

Influence of vitamin E and carcass feeding supplementation on fecal glucocorticoid and androgen metabolites in male black-footed ferrets (Mustela nigripes)

In recent years, the ex situ population of the endangered black-footed ferret (Mustela nigripes; ferret) has experienced a decline in normal sperm morphology (from 50% to 20%), which may be linked to inbreeding depression and/or a dietary change. We examined the effects of adding carcass and vitamin E to the diet on stress and reproductive biomarkers in male ferrets (n = 42 males including 16 juveniles and 26 adults) housed at the U.S. Fish and Wildlife National Black-footed Ferret Conservation Center (Carr, CO, USA). Fecal samples (3x/week) were collected from November and December (pre-breeding season, no diet change), February through May (breeding season, diet change) and June (post-breeding season, diet change) and analyzed for fecal glucocorticoid metabolites (FGM) via a corticosterone enzyme immunoassay (EIA). A subset of samples from adult males (n = 15) were analyzed for fecal androgen metabolites (FAM) via a testosterone EIA. We first used a linear mixed effects model to identify the important fixed effects among meat treatment, vitamin E treatment, age class (juvenile or adult), and all possible interactions on each hormone. We then examined the important factor’s effects across seasons using the non-parametric Friedman test. We found that age did not influence (p = 0.33) FGMs; however there was a significant effect of meat treatment on FGM (p = 0.04) and an effect of vitamin E on FAMs (p<0.10). When fed carcass, FGMs declined (p<0.001) from pre- to the during the breeding season time period, but was similar (p>0.05) between during and post-breeding season periods. Males that were not fed carcass had higher (p<0.05) FGMs during the breeding season compared to pre- and post-breeding season and FGMs were lower (p<0.05) in the post-breeding season compared to pre-breeding season. Males fed with carcass had lower (p<0.001) FGM than males that were not fed carcass during both the pre-breeding and the breeding season but not during the post-breeding season (p>0.05). Males supplemented with vitamin E had higher (p<0.001) FAM than non-supplemented males during the breeding season only. For both groups, FAM was highest (p<0.05) during the breeding season. In conclusion, adding carcass to the diet can reduce glucocorticoid production and adding vitamin E can increase testosterone during the breeding season, which may influence reproductive success.

Effect of L-carnitine on the expression of the apoptotic genes Bcl-2 and Bax

OBJECTIVE

The genes Bcl-2 and Bax play important roles in apoptosis. Many studies have shown that formalin has a strong deleterious effect on male fertility and can induce apoptosis. L-carnitine has been reported to potentially reverse the negative effects of formalin, leading to improved spermatogenesis. In this study, we examined the levels of expression of Bcl-2 and Bax in mice treated with formalin and L-carnitine.

METHODS

Thirty adult BALB/c mice were categorized into three groups. The mice in the control group (n=10) were not injected with any substance. The mice in the second group (n=10) received 10 mg/kg of formalin daily via an intraperitoneal injection, while those in the final group (n=10) were intraperitoneally injected daily with a dose of 10 mg/kg of formalin and 100 mg/kg of L-carnitine. All mice were kept in isolated cages for 31 days.

RESULTS

The expression of Bax was significantly higher in the formalin-treated mice than in the mice of the control group, while the expression of Bcl-2 was significantly lower in the formalin-treated mice than in the control mice. Additionally, relative to control mice, Bcl-2 expression increased and Bax expression decreased in the mice administered both formalin and L-carnitine.

CONCLUSION

In this study, L-carnitine was shown to augment Bcl-2 expression and to reduce Bax expression, indicating that this compound may inhibit apoptosis. Due to its positive effects, L-carnitine can be used as a prophylactic treatment for people who routinely come into direct contact with formalin as an occupational hazard.

Role of isoprostanes in human male infertility

One of the major causes of defective sperm function is oxidative stress, which limits the fertilizing potential of these cells as the result of collateral damage to proteins and lipids in the sperm plasma membrane. On this point, a derangement of both generation and neutralization of reactive oxygen species (ROS) is a recognized cause of male infertility. Antioxidant protection in sperm has been widely investigated, as well as the sperm composition of fatty acids (FA), which represents the preferred substrate for ROS, most frequently linked to the disease-related infertility. Isoprostanes are compounds derived from free radical-mediated oxidation of FAs. As such, they are considered an index of lipid oxidative damage and lipid mediators. This article discusses the role of isoprostanes as relevant factors both to sperm FA composition and sperm membrane integrity. Additionally, isoprostane's influence on sperm quality is reviewed. With reference to male reproductive dysfunction, increasing evidence indicates isoprostanes, detectable in biological fluids or sperm membrane, as the specific index of 1) exposure to chemical etiological agents, 2) oxidative damage, 3) reduced antioxidant response, and 4) sperm immaturity.

ABBREVIATIONS

OS: oxidative stress; ROS: reactive oxygen species; PUFAs: polyunsaturated fatty acids; ARA: arachidonic acid, F₂-IsoPs; F₂-isoprostanes, PLA₂: phospholipase A₂; NADPH: nicotinamide adenine dinucleotide phosphate; IVF: in vitro fertilization.

Leptin and its actions on reproduction in males

Leptin, an adipocyte-derived hormone, serves numerous physiological functions in the body, particularly during puberty and reproduction. The exact mechanism by which leptin activates the gonadotropin-releasing hormone (GnRH) neurons to trigger puberty and reproduction remains unclear. Given the widespread distribution of leptin receptors in the body, both central and peripheral mechanisms involving the hypothalamic-pituitary-gonadal axis have been hypothesized. Leptin is necessary for normal reproductive function, but when present in excess, it can have detrimental effects on the male reproductive system. Human and animal studies point to leptin as a link between infertility and obesity, a suggestion that is corroborated by findings of low sperm count, increased sperm abnormalities, oxidative stress, and increased leptin levels in obese men. In addition, daily leptin administration to normal-weight rats has been shown to result in similar abnormalities in sperm parameters. The major pathways causing these abnormalities remain unidentified; however, these adverse effects have been attributed to leptin-induced increased oxidative stress because they are prevented by concurrently administering melatonin. Studies on leptin and its impact on sperm function are highly relevant in understanding and managing male infertility, particularly in overweight and obese men.

Inclusion of ovine enriched serum with vitamin E and polyunsaturated fatty acids in the freezing medium: a new strategy to improve human frozen-thawed sperm parameters

The objective was to evaluate the effect of inclusion of 2.5% and 5% ovine serum, enriched with vitamin E (Vit E) and fish oil (FO), in human sperm freezing medium. Serum samples were prepared from sixteen rams (n = 4) feeding on a without supplemented diet, and diets supplemented with Vit E, FO and Vit E + FO. Semen samples, from 60 normozoospermic men, were frozen in: (I) a commercial freezing medium (SpermFreeze™; control medium), (II) the commercial freezing medium containing foetal bovine serum, (III) the commercial freezing medium + nonenriched serum (serum group), (IV) the commercial freezing medium + Vit E enriched serum (Vit E group), (V) the commercial freezing medium + FO enriched serum (FO group) and (VI) the commercial freezing medium + Vit E + FO enriched serum (Vit E + FO group). Sperm total and progressive motility, morphology, viability and plasma membrane integrity were significantly higher (p ≤ .05) in Vit E and Vit E + FO groups compared with the control group. Mitochondrial membrane potential did not differ between treatments (p > .05). It was concluded that ovine serum enriched with vitamin E and vitamin E + FO improved the quality of human spermatozoa but enriched serum containing FO could not improve the sperm cryo-injuries.

Effect of olive-derived antioxidants (3,4-dihydroxyphenylethanol and 3,4 dihydroxyphenylglycol) on sperm motility and fertility in liquid ram sperm stored at 15°C or 5°C

The aim of the present study was to evaluate the effect of the addition of two olive oil-derived antioxidants, hydroxytyrosol (3,4-dihydroxyphenylethanol, HT) and 3,4-dihydroxyphenylglycol (DHPG), on ovine semen during liquid storage at 5°C and 15°C. Semen was collected, pooled, diluted and then divided into aliquots supplemented with different concentrations (5 μg/ml, 10 μg/ml, 50 μg/ml and 100 μg/ml) of HT, DHPG and a mixture (MIX) of both antioxidants. Sperm motility characteristics were assessed in the different samples at 0, 6, 24, 48, 72 and 96 hr after cooling, and a fertility trial was also conducted. The results showed that the antioxidant addition did not significantly improve total and progressive motility in ovine cooled sperm maintained at 15° or 5°C. However, in samples stored at 5°C, LIN (48, 72, 96 hr), STR (0 hr) and WOB (0, 48, 72, 96 hr) values significantly decreased in comparison with control treatment when high antioxidant concentrations were added (MIX100 or HT100). When samples were maintained at 15°C, MIX50 showed significantly higher VCL values than the control treatment after 6 hr cooling, and MIX100 showed significantly lower VCL values at 96 hr after cooling. According to the artificial insemination trial, no significant differences were observed when antioxidants were added. In conclusion, the use of HT and DHPG showed small impact in sperm motility and fertility was not affected (nor detrimentally nor positively) when insemination was carried out using antioxidant-supplemented liquid sperm.

Effects of Diets Enriched in Linseed and Fish Oil on the Expression Pattern of Toll-Like Receptors 4 and Proinflammatory Cytokines on Gonadal Axis and Reproductive Organs in Rabbit Buck

Infections of the genital tract can perturb the fertility in humans and animals. Pathogen recognition and activation of innate immunity onset through the pattern recognition receptor activation, such as Toll-like receptor 4 (TLR4), leading to the production of proinflammatory cytokines and mediators. TLR4 is expressed both on leukocytes and nonimmune cells. Rabbit TLR4 shows great similarity to its human counterpart. Moreover, the TLR4 signalling pathway could be modulated by long-chain polyunsaturated fatty acids (LC-PUFA). The objectives of this study were (i) to determine the expression levels of TLR4 and proinflammatory cytokines in the reproductive hypothalamic-gonadal axis of the male rabbit and (ii) to evaluate if the n-3 PUFA-enriched diets can modify their expression levels in the tissues and LC-PUFA profiles in seminal plasma. Fifteen rabbit bucks (n = 5/experimental group) were fed with different diets: commercial standard (group C), rich in extruded linseed (10%, group L), and in fish oil (3%, group FO) for 110 days. TLR4, TNF-α, and IL-1β mRNA were ubiquitously expressed throughout the hypothalamic-gonadal axis. However, TLR4 mRNA expression was lower in the hypothalamus than the epididymis (P < 0.01), seminal vesicles (P < 0.01), and pituitary gland (P < 0.05). Dietary enrichment in PUFA did not modify the gene expression profile nor the histological characteristics of the tissues. Conversely in seminal plasma, rabbits fed with L and FO had lower n-6 (P < 0.05), LC-PUFA n-6 (P < 0.05), and n-6/n-3 ratio (P < 0.05) but higher n-3 (P < 0.001) and LC-PUFA n-3 (P < 0.01) compared to the control group. Our study builds a map of the gene expression of TRL4 and proinflammatory cytokines in the reproductive hypothalamic-gonadal axis of the male rabbit, fundamental step for understanding the immune defence mechanisms. Diets enriched in LC-PUFA did not affect basal gene expression but modulated sperm fatty acid composition. Finally, rabbit may be an excellent animal model to study the relationship between inflammation and infertility, and the nutritional modulation of immune functions.

Attenuation of sleep deprivation dependent deterioration in male fertility parameters by vitamin C

PURPOSE

Male fertility is multifaceted and its integrity is as well multifactorial. Normal spermatogenesis is dependent on competent testicular function; namely normal anatomy, histology, physiology and hormonal regulation. Lifestyle stressors, including sleep interruption and even deprivation, have been shown to seriously impact male fertility. We studied here both the effects and the possible underlying mechanisms of vitamin C on male fertility in sleep deprived rats.

METHODS

Thirty male Wistar albino rats were used in the present study. Rats were divided (10/group) into: control (remained in their cages with free access to food and water), sleep deprivation (SD) group (subjected to paradoxical sleep deprivation for 5 consequent days, rats received intra-peritoneal injections of vehicle daily throughout the sleep deprivation), and sleep deprivation vitamin C-treated (SDC) group (subjected to sleep deprivation for 5 consequent days with concomitant intra-peritoneal injections of 100 mg/kg/day vitamin C). Sperm analysis, hormonal assay, and measurement of serum oxidative stress and inflammatory markers were performed. Testicular gene expression of Nrf2 and NF-κβ was assessed. Structural changes were evaluated by testicular histopathology, while PCNA immunostaining was conducted to assess spermatogenesis.

RESULTS

Sleep deprivation had significantly altered sperm motility, viability, morphology and count. Serum levels of cortisol, corticosterone, IL-6, IL-17, MDA were increased, while testosterone and TAC levels were decreased. Testicular gene expression of Nrf2 was decreased, while NF-κβ was increased. Sleep deprivation caused structural changes in the testes, and PCNA immunostaining showed defective spermatogenesis. Administration of vitamin C significantly countered sleep deprivation induced deterioration in male fertility parameters.

CONCLUSION

Treatment with vitamin C enhanced booth testicular structure and function in sleep deprived rats. Vitamin C could be a potential fertility enhancer against lifestyle stressors.

Protective effect of curcumin on fertility in cyclophosphamide exposed rats: Involvement of multiple pathways

This study assesses the effect of curcumin on cyclophosphamide (CPA)-induced functional alterations of the testicular, brain, and pituitary axis in common rodents, rats. Only CPA was given at 150 mg/kg body weight only on Day 1 or orally pre and posttreated with curcumin at 20 mg/kg body weight successively for 14 days. The outcomes showed that curcumin pre and posttreatments significantly affected the elevation of biomarkers of oxidative stress in CPA-induced rats, moreover, it increased nonenzymatic antioxidant levels in the epididymis, testes, and brain of the treated rats used in this study. In addition, followed by the preservation of histo-architectures of the epididymis, testes, and brain in the rats treated with CPA, curcumin helped in increasing the sperm quality and quantity and suppressing both the inflammatory indices and the activities of caspase-3, while pretreatment with curcumin gave a better result than posttreatment with curcumin. This may, therefore, represent a prospective adjuvant against CPA-induced spermatogenic deficits in humans. PRACTICAL APPLICATIONS: Jointly, through the antiapoptotic, antioxidant, and anti-inflammatory activities of curcumin, it instigated the toxicity of CPA-induced to be modulated along the testicular, brain, and pituitary axis in the rats. This may, therefore, represent a prospective therapeutic adjuvant against CPA-induced spermatogenic deficits in humans.

Novel association between apoptotic sperm biomarkers with seminal biochemical parameters and acetylcholinesterase activity in patients with teratozoospermia

OBJECTIVE

We aimed to determine whether the dysfunction of physiological apoptosis and specific seminal biochemical parameters could be associated with male infertility and sperm morphological defects.

STUDY DESIGN

Ejaculated sperm samples from sixty patients with isolated teratozoospermia and thirty fertile donors were analyzed. The proportion of both viable and dead spermatozoa expressing activated caspases was detected by fluorescence microscopy through the use of different specific carboxyfluorescein-labeled caspase inhibitors FLICA. The different stages of apoptosis in human were qualitatively and quantitatively determined by using the AO/EB fluorescent staining method. The levels of the seminal biochemical parameters (acetylcholinesterase (AChE), lactate dehydrogenase (LDH), creatine phosphokinase (CK), iron (Fe), calcium (Ca), and phosphorus (P)) were evaluated spectrophotometrically.

RESULTS

Patients with teratozoospermia showed significantly higher proportions of dead and live spermatozoa with activated caspases and spermatozoa in the late stage of apoptosis when compared to controls. Among the different studied biochemical seminal parameters, the rates of acetylcholinesterase activity, creatine phosphokinase, iron, and calcium were significantly increased in the patient group. However, the rate of phosphorus was significantly decreased. Interestingly, significant relationships were found between the studied biochemical and apoptotic biomarkers and the rates of atypical sperm forms with the incidences of head, mid-piece, and tail abnormalities. Furthermore, positive correlations were found between P, AChE, Fe, CK, and LDH with apoptotic markers.

CONCLUSIONS

These results emphasize the impact of apoptosis in the pathophysiology of teratozoospermia and suggest that seminal biochemical disturbance may arise such damage.

Appraisal of immediate and late effects of mobile phone radiations at 2100 MHz on mitotic activity and DNA integrity in root meristems of Allium cepa

The present study evaluated the potential of 2100 MHz radiofrequency radiations to act as cytotoxic and genotoxic agent. Fresh onion (Allium cepa L.) roots were exposed to electromagnetic field radiations (EMF-r) for different durations (1 h and 4 h) and evaluated for mitotic index (MI), phase index, chromosomal aberrations, and DNA damage. DNA damage was investigated with the help of the comet assay by assessing various parameters like % head DNA (HDNA), % tail DNA (TDNA), tail moment (TM), and olive tail moment (OTM). Effects of EMF-r exposure were also compared with that of methyl methanesulfonate (MMS; 90 μM), which acted as a positive control. The post-exposure effects of EMF-r after providing the test plants with an acclimatization period of 24 h were also evaluated. Compared to the control, a significant increase in the MI and aberration percentage was recorded upon 4 h of exposure. However, no specific trend of phase index in response to exposure was detected. EMF-r exposure incited DNA damage with a significant decrease in HDNA accompanied by an increase in TDNA upon exposure of 4 h. However, TM and OTM did not change significantly upon exposure as compared to that of control. Analysis of the post-exposure effects of EMF-r did not show any significant change/recovery. Our data, thus, suggest the potential cytotoxic and genotoxic nature of 2100 MHz EMF-r. Our study bears great significance in view of the swiftly emergent EMF-r in the surrounding environment and their potential for inciting aberrations at the chromosomal level, thus posing a genetic hazard.

Are There Any Relationships Between Abnormal Seminal Parameters and Neutrophil-Lymphocyte Ratio, Platelet-Lymphocyte Ratio, and Red Blood Cell Distribution-Platelet Ratio?

Objective The aim of this study is to determine the relationship between neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), and red blood cell distribution width (RDW)/platelet ratio (RPR) values, which are pro-inflammatory markers, with abnormal sperm parameters, and to evaluate their availability as predictive markers. Materials and methods A total of 160 patients, 80 of whom were the control group, formed with match-pair analysis (Group 1), and 80 patients with abnormal sperm analysis, who met the study criteria (Group 2), were included in the study. Complete blood count results were recorded. NLR, PLR, and RPR values were calculated using hematological parameters, and a comparison was made between the two groups. Results The mean age was 31.23 ± 5.1 years in Group 1 and 31.33 ± 6.4 years in Group 2. NLR values were 1.84 ± 0.57-1.87 ± 0.65 (P =0.77), PLR values were 105.42 ± 23.89-111.42 ± 34.54 (P = 0.62) and RPR values were 0.05 ± 0.009-0.05 ± 0.01 (P =0.45), respectively. There was no statistically significant difference between the groups. Conclusions We investigated whether NLR, PLR, and RPR results can be used as a predictive marker on abnormal sperm parameters. We do not recommend the use of these parameters as a predictive marker.

Stress Hormone and Oxidative Stress Biomarkers Link Obesity and Diabetes with Reduced Fertility Potential

Objective

Tilting the balance in favor of antioxidant agents could increase infertility problems in obese and diabetic individuals. The aim of this study was to evaluate oxidative stress status in semen of men with type 2 diabetes and obesity to investigate whether excessive amounts of oxidative stress, as a result of diabetes and obesity, influence infertility potential.

Materials and Methods

A case-control study was conducted in men (n=150) attending the Infertility Center of Royan Institute between December 2016 and February 2017. Participants were categorized into four groups; normal weight (BMI<25 kg/m²) and non-type-2 diabetic (control=40), obese and non- type-2 diabetic (obese=40), non-obese and type- 2 diabetic (Nob-DM=35), and obese and type-2 diabetic (Ob-DM=35). The semen analysis was performed according to the World Health Organization criteria. Oxidative stress, DNA fragmentation, sperm apoptosis, and total antioxidant capacity (TAC) were evaluated in semen samples of men. Serum glucose, HbA1c, cortisol, and testosterone levels were determined using the enzyme-linked immunosorbent assay (ELISA) method.

Results

Compared with the control group, sperm motility, progressive motility, and normal morphology were significantly decreased in the obese, Nob-DM, and Ob-DM groups (P<0.01). The obese, Nob-DM, and Ob-DM groups showed significantly lower levels of TAC and higher amounts of oxidative stress, early apoptotic sperm, and the percentage of DNA fragmentation as compared with the control group (P<0.05). Testosterone concentration was decreased in the obese, Nob-DM, and Ob-DM groups when compared with healthy individuals (P<0.05), whereas the cortisol level was significantly increased in the Nob-DM and Ob-DM groups in comparison to the obese and control group (P<0.01).

Conclusion

Increased amount of reactive oxygen species (ROS) levels and DNA fragmentation in men affected by either diabetes or obesity could be considered prognostic factors in sub-fertile patients, alerting physicians to an early screen of male patients to avoid the development of infertility in prone patients.

Potential inhibitory effect of swimming exercise on the Kisspeptin-GnRH signaling pathway in male rats

Aerobic exercises are considered as an effective method of improving several undesirable health outcomes; however, their implications in the male reproductive axis have remained controversial. The present study evaluated the impact of physical exercise on the male reproductive system in rats and investigated the potential central and peripheral mechanisms involved in it. Twenty male Sprague-Dawley rats were randomly divided into control and exercise groups, with 10 rats per group. The rats were subjected to a swimming exercise for 60 min/day for five days a week and the protocol was followed for six constitutive weeks. We found that the swimming exercise significantly decreased the testicular weight and the testicular somatic index. Furthermore, there was a marked reduction in several sperm characteristics, including sperm count, motility, morphology, and viability in the exercised rats. The serum levels of reproductive hormones, i.e., testosterone (T), luteinizing hormone (LH), and follicle stimulating hormone (FSH) were significantly decreased. A histological examination of testes and epididymis revealed defective spermatogenesis. Molecular analysis revealed the downregulation of the expression of mRNAs of the hypothalamic kisspeptin (Kiss1), Kiss1 receptor (Kiss1r), gonadotropin-releasing hormone (GnRH1), GnRH1 receptor (GnRHr), and testicular Kiss1r along with an upregulation in the gene expression of GnRHr in the pituitary. We also observed a significant reduction in the activity and the expression of mRNAs of testicular superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) and a marked elevation in the levelsof malondialdehyde (MDA). These findings implied that chronic swimming exercise suppressed the Kisspeptin-GnRH signaling pathway, consequently reducing the production of male reproductive hormones. A simultaneous increase in the oxidative stress could contribute to exercise-induced inhibition of male reproductive functions. To conclude, an appropriate training program is important to maximize the benefits and minimize the side effects of physical exercises on the male reproductive system.

Reduced sperm telomere length in individuals with varicocele is associated with reduced genomic integrity

Varicocele, defined as enlarged varicose veins in the scrotum, is the most common identifiable cause of male infertility. There are significant correlations between oxidative stress and varicocele-related infertility due to testicular hyperthermia, which can result in low sperm function. In addition, recent excessive oxidative stress can affect sperm telomere length and integrity of sperm DNA. Therefore, we assessed sperm telomere length as a potential marker of paternal genome integrity and leukocyte telomere length as an internal control (real-time PCR), along with sperm chromatin status (TUNEL and chromomycin A3 assay), and lipid peroxidation (Bodipy probe) in 18 infertile men with grade II or III varicocele, and 20 fertile men. Means of sperm parameters, sperm and leukocyte telomere length were significantly lower, while means of sperm DNA fragmentation, protamine deficiency, and lipid peroxidation were significantly higher in infertile men with varicocele compared to fertile men. Therefore, shortened telomere length in sperm and leukocytes is likely associated with increased oxidative stress related to the state of varicocele, which also accounts for increase in sperm DNA fragmentation. Thus, assessment of leukocyte telomere length could be taken as an indicator of antioxidant capacity in an individual, which also affects sperm function.

Ameliorative effects of Saussurea lappa root aqueous extract against Ethephon-induced reproductive toxicity in male rats

This study was designed to evaluate protective effect of Saussurea lappa root aqueous extract against Ethephon (2-chloroethylphosphonic acid)-induced reproductive toxicity in rats. Control group received distilled water. Second group was given S. lappa extract at a dose 50 mg/kg bw. Third group was given Ethephon at a dose 200 mg/kg bw. Fourth, fifth, and sixth groups were given S. lappa extract before, with or after Ethephon administration, respectively. Ethephon intoxication significantly decreased serum levels of follicle stimulating hormone, luteinizing hormone, testosterone, and prolactin. Also, it significantly decreased sperms count, vitality, morphology index, total motility, progressive motility, and proliferating cell nuclear antigen protein expressions in spermatogonia. However, it significantly increased sperms abnormalities, testicular tissue and DNA damages, P53 protein expressions, noprogressive motility, and immotile sperms. In contrast, S. lappa extract ameliorated these alterations. These results indicated that S. lappa had potential preventive and curative effects against Ethephon-induced reproductive toxicity in rats.

The Effect of Dietary Supplementation of Vitamin E, Selenium, Zinc, Folic Acid, and N-3 Polyunsaturated Fatty Acids on Sperm Motility and Membrane Properties in Dogs

Sub-fertility represents a common challenge in canine reproduction. Different protocols, supplementing daily given quantities of micronutrients, were investigated to improve poor sperm concentration and/or function, which represent breeding major constraining factors in the canine species. Little information is available for dogs concerning the effect of a daily supplementation with a complex of vitamin E, zinc, selenium, folic acid, and n-3 polyunsaturated fatty acids (PUFA) on semen quality. Thus, the present study investigated this effect on semen motility and sperm membrane properties. Serial semen analyses from fourteen healthy normospermic dogs, fed with the same commercial diet, were performed on Days 0 (T0), 30 (T30), 60 (T60), and 90 (T90). Seven dogs were randomly included in the treatment (T) group, receiving a supplementation of vitamin E, zinc, selenium, folic acid, n-3 PUFA; and seven other subjects composed the control (C) group. Total Sperm Count (TSC), Computer-Assisted Sperm Analysis (CASA) indexes, mortality, and functional membrane integrity were assessed. The ANOVA compared results between groups and sampling times (p < 0.05). From T60, the supplementation significantly improved TSC, progressive motility, functional membrane integrity, and decreased mortality. Present results lead us to consider ameliorative effects of a two-month healthy diet supplementation on canine spermatozoa. The positive effects of the described balanced integration of micronutrients on sperm motility and prevention of oxidative stress should be considered, especially when decreased seminal parameters may result from inadequate intake, reduced absorption, increased losses or demand, or to attenuate the impact of age.

Effect of different olive oil-derived antioxidants (hydroxytyrosol and 3,4-dihydroxyphenylglycol) on the quality of frozen-thawed ram sperm

The aim of the present study was to evaluate the effect of the addition of different concentrations of two olive oil-derived antioxidants, hydroxytyrosol (3,4-dihydroxyphenylethanol, HT) and 3,4-dihydroxyphenylglycol (DHPG), on ovine semen during the freezing-thawing process. Sperm was collected, pooled and diluted with commercial extenders and then divided into aliquots supplemented with different concentrations (10 μg/ml, 30 μg/ml, 50 μg/ml and 70 μg/ml) of HT, DHPG and a mixture (MIX) of both antioxidants. A control group, without antioxidant, was also prepared. Sperm motility, viability, acrosome integrity, mitochondrial membrane potential and lipid peroxidation (LPO) were assessed. The results showed that frozen-thawed ram spermatozoa exhibited lower values for motility, membrane integrity, acrosome and mitochondrial membrane potential than fresh samples (P ≤ 0.01). However, when antioxidants were added, thawed spermatozoa exhibited relatively low LPO, recording values similar to fresh spermatozoa; by contrast, the control group of frozen-thawed spermatozoa without antioxidants exhibited significantly higher LPO (P ≤ 0.01). The addition of a HT+DHPG mixture (MIX) had a negative impact on sperm membrane and acrosome integrity, suggesting that a pure antioxidant supplementation has the potential to offer superior results. In conclusion, HT and DHPG exhibited a positive effect on the frozen-thawed spermatozoa inasmuch as they reduced the LPO. These olive oil-derived antioxidants have the potential to improve frozen-thawed sperm quality, although further studies should be carried out to analyse the antioxidant effect at different times after thawing.