Mitochondrial Reactive Oxygen Species (ROS) Production Alters Sperm Quality

Praseodymium and warming interactions in mussels: Comparison between observed and predicted results

Being a crucial element for technological development, praseodymium (Pr) has been increasingly used, leading to a rise in its concentration in aquatic systems. However, its potential threats to organisms remain poorly understood. Besides contamination, organisms are also threatened by climate change-related factors, including warming. It is important to evaluate how climate change-related factors may influence the effects of contaminants. To address this, histopathological and biochemical analyses were performed in adult mussels of Mytilus galloprovincialis, following a 28-day exposure to Pr (10 μg/L) and warming (4 °C increase) separately, and in combination. Additionally, biochemical and physiological alterations were analysed in the sperm of mussels after 30-min exposure to the same treatments. Furthermore, it was used the Independent Action model to predict the interaction between Pr and warming. The results showed, in the case of adults exposed to Pr, an increase in superoxide dismutase (SOD) and glutathione S-transferases (GSTs) activities. However, it was insufficient, leading to histopathological injuries, redox imbalance, and cellular damage. In the case of sperm, Pr induced an increase of mitochondrial activity and respiration rate, in response to the increase in systemic metabolic rate and oxygen demand. Warming increased the metabolism, and induced redox imbalance and cellular damage in adults. In sperm, a rise in temperature induced lipid peroxidation and a decrease in velocity. Warming induced some alterations in how adult mussels responded to Pr, activating catalase instead of SOD, and in addition to GSTs, also activated carboxylesterases. However, it was not enough to avoid redox imbalance and cellular damage. In the case of sperm, the combination induced a decrease in H2O2 production, and higher oxygen demand, which prevented the decrease in motility and velocity. This study highlights the limitations of using models and emphasizes the importance of studying the impacts of emerging contaminants, such as rare earth elements, and their combination with climate change-related factors. Under environmental conditions, chronic exposure to the combined effect of different stressors might generate impacts at higher biological levels. This may affect organisms' respiratory and filtration capacity, nutrient absorption, defence capacity against infections or diseases, and sperm viability, ultimately resulting in reduced growth and reproduction, with consequences at the population level.

Mitigation of Oxidative Stress in Idiopathic Pulmonary Fibrosis Through Exosome-Mediated Therapies

Idiopathic pulmonary fibrosis (IPF) poses a formidable clinical challenge, characterized by the thickening of alveolar septa and the onset of pulmonary fibrosis. The pronounced activation of oxidative stress emerges as a pivotal hallmark of inflammation. Traditional application of exogenous antioxidants proves inadequate in addressing oxidative stress, necessitating exploration into strategies to augment their antioxidant efficacy. Exosomes, nano-sized extracellular vesicles harboring a diverse array of bioactive factors, present as promising carriers with the potential to meet this challenge. Recent attention has been directed towards the clinical applications of exosomes in IPF, fueling the impetus for this comprehensive review. We have compiled fresh insights into the role of exosomes in modulating oxidative stress in IPF and delved into their potential as carriers for regulating endogenous reactive oxygen species generation. This review endeavors to bridge the divide between exosome research and IPF, traversing from bedside to bench. Through the synthesis of recent findings, we propose exosomes as a novel and promising strategy for improving the outcomes of IPF therapy.

DNA methylation patterns in patients with asthenospermia and oligoasthenospermia

BACKGROUND

Spermatogenesis is a highly regulated and complex process in which DNA methylation plays a crucial role. This study aimed to explore the differential methylation profiles in sperm DNA between patients with asthenospermia (AS) and healthy controls (HCs), those with oligoasthenospermia (OAS) and HCs, and patients with AS and those with OAS.

RESULTS

Semen samples and clinical data were collected from five patients with AS, five patients with OAS, and six age-matched HCs. Reduced representation bisulfite sequencing (RRBS) was performed to identify differentially methylated regions (DMRs) in sperm cells among the different types of patients and HCs. A total of 6520, 28,019, and 16,432 DMRs were detected between AS and HC, OAS and HC, and AS and OAS groups, respectively. These DMRs were predominantly located within gene bodies and mapped to 2868, 9296, and 9090 genes in the respective groups. Of note, 12, 9, and 8 DMRs in each group were closely associated with spermatogenesis and male infertility. Furthermore, BDNF, SMARCB1, PIK3CA, and DDX27; RBMX and SPATA17; ASZ1, CDH1, and CHDH were identified as strong differentially methylated candidate genes in each group, respectively. Meanwhile, the GO analysis of DMR-associated genes in the AS vs. HC groups revealed that protein binding, cytoplasm, and transcription (DNA-templated) were the most enriched terms in the biological process (BP), cellular component (CC), and molecular function (MF), respectively. Likewise, in both the OAS vs. HC and AS vs. OAS groups, GO analysis revealed protein binding, nucleus, and transcription (DNA-templated) as the most enriched terms in BP, CC, and MF, respectively. Finally, the KEGG analysis of DMR-annotated genes and these genes at promoters suggested that metabolic pathways were the most significantly associated across all three groups.

CONCLUSIONS

The current study results revealed distinctive sperm DNA methylation patterns in the AS vs. HC and OAS vs. HC groups, particularly between patients with AS and those with OAS. The identification of key genes associated with spermatogenesis and male infertility in addition to the differentially enriched metabolic pathways may contribute to uncovering the potential pathogenesis in different types of abnormal sperm parameters.

Donepezil and quercetin alleviate valproate-induced testicular oxidative stress, inflammation and apoptosis: Imperative roles of AMPK/SIRT1/ PGC-1α and p38-MAPK/NF-κB/ IL-1β signaling cascades

The mounting evidence of valproate-induced testicular damage in clinical settings is alarming, especially for men taking valproate (VPA) for long-term or at high doses. Both donepezil (DON) and quercetin (QUE) have promising antioxidant, anti-inflammatory, and anti-apoptotic effects. Therefore, this study aimed to determine whether DON, QUE, and their combination could mitigate VPA-induced testicular toxicity and unravel the mechanisms underlying their protective effect. In this study, male albino rats were randomly categorized into six equal groups: control, VPA (500 mg/kg, I.P., for 14 days), DON (3 and 5 mg/kg), QUE (50 mg/kg), and DON 3 + QUE combination groups. The DON and QUE treatments were administered orally for 7 consecutive days before VPA administration and then concomitantly with VPA for 14 days. VPA administration disrupted testicular function by altering testicular architecture, ultrastructure, reducing sperm count, viability, and serum testosterone levels. Additionally, VPA triggered oxidative damage, inflammatory, and apoptotic processes and suppressed the AMPK/SIRT1/PGC-1α signaling cascade. Pretreatment with DON, QUE, and their combination significantly alleviated histological and ultrastructure damage caused by VPA and increased the serum testosterone level, sperm count, and viability. They also suppressed the oxidative stress by reducing testicular MDA content and elevating SOD activity. In addition, they reduced the inflammatory response by suppressing IL-1β level, NF-κB, and the p38-MAPK expression as well as inhibiting apoptosis by diminishing caspase-3 and increasing Bcl-2 expression. These novel protective effects were mediated by upregulating AMPK/SIRT1/PGC-1α signaling cascade. In conclusion, these findings suggest that DON, QUE, and their combination possess potent protective effects against VPA-induced testicular toxicity.

Impacts of Acrylamide on testis and spermatozoa

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

Uncovering the impact of alcohol on internal organs and reproductive health: Exploring TLR4/NF-kB and CYP2E1/ROS/Nrf2 pathways

This review delves into the detrimental impact of alcohol consumption on internal organs and reproductive health, elucidating the underlying mechanisms involving the Toll-like receptor 4 (TLR4)/Nuclear factor kappa light chain enhancer of activated B cells (NF-kB) pathway and the Cytochrome P450 2E1 (CYP2E1)/reactive oxygen species (ROS)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathways. The TLR4/NF-kB pathway, crucial for inflammatory and immune responses, triggers the production of pro-inflammatory agents and type-1 interferon, disrupting the balance between inflammatory and antioxidant responses when tissues are chronically exposed to alcohol. Alcohol-induced dysbiosis in gut microbes heightens gut wall permeability to pathogen-associated molecular patterns (PAMPs), leading to liver cell infection and subsequent inflammation. Concurrently, CYP2E1-mediated alcohol metabolism generates ROS, causing oxidative stress and damaging cells, lipids, proteins, and deoxyribonucleic acid (DNA). To counteract this inflammatory imbalance, Nrf2 regulates gene expression, inhibiting inflammatory progression and promoting antioxidant responses. Excessive alcohol intake results in elevated liver enzymes (ADH, CYP2E1, and catalase), ROS, NADH, acetaldehyde, and acetate, leading to damage in vital organs such as the heart, brain, and lungs. Moreover, alcohol negatively affects reproductive health by inhibiting the hypothalamic-pituitary-gonadal axis, causing infertility in both men and women. These findings underscore the profound health concerns associated with alcohol-induced damage, emphasizing the need for public awareness regarding the intricate interplay between immune responses and the multi-organ impacts of alcohol consumption.

Effects of melatonin on sperm quality, enzyme activity, antioxidant gene expression and fertility of cryopreserved bovine semen

Melatonin (MLT) has strong antioxidant capacity and can reduce the damage caused by oxidative stress in sperm, but there is still little content in the field we have studied. In this study, we are committed to scientific research on adding melatonin to Belgian blue bull semen diluent for cryopreservation. Different concentrations (0, 0.1, 0.3, 0.5 or 0.7 mg/mL) of MLT were added diluent. Sperm kinetic parameters, enzyme activity, antioxidant gene expression and fertility were analyzed after thawing. The results showed that MLT concentration of 0.3 mg/mL exerted positive effects on post-thaw kinetic parameters. Compared with other groups, 0.3 mg/mL MLT treated sperm acrosome and plasma membrane integrity, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels significantly increased. Meanwhile, the mRNA expression of antioxidant genes SOD2, CAT and GPx increased in the 0.3 mg/mL MLT treatment group, and the mRNA expression of apoptosis genes Caspase-3 and Bax were significantly reduced. In addition, in vitro fertilization (IVF) embryo cleavage, blastocyst rate and artificial insemination (AI) pregnancy rate were higher in 0.3 mg/mL MLT. Therefore, MLT showed cryoprotective capacity to the freezing diluent used for Belgian blue bull sperm during the process of freezing-thawing, and the optimal concentration of MLT for the frozen diluent was 0.3 mg/mL.

CDX2 alleviates hypoxia-induced apoptosis and oxidative stress in spermatogenic cells through suppression of reactive oxygen species-mediated Wnt/β-catenin pathway

Hypoxia-induced apoptosis and oxidative stress in spermatogenic cells are considered to be important factors leading to male infertility. It was reported that CDX2 expression was downregulated in hypoxia-stimulated spermatogenic cells. However, the effects of CDX2 on hypoxia-induced apoptosis and oxidative stress in spermatogenic cells are still unknown. This study aimed to explore the roles of CDX2 in hypoxia-induced injury of spermatogenic cells, as well as its mechanism of action. Spermatogenic cells were cultured under 1% oxygen for 48 h to established hypoxia damage model. Reactive oxygen species (ROS) generation was determined using 2',7'-dichlorofluorescein diacetate assay. Apoptosis was assessed using flow cytometry. Enzyme-linked immunosorbent assay was used to evaluate oxidative stress markers, including malondialdehyde (MDA) content and the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidases (GSH-Px). Protein levels were detected using western blotting. Hypoxia exposure induced increase in ROS generation, apoptosis rate, and oxidative stress in spermatogenic cells. ROS scavenger inhibited hypoxia-induced apoptosis, oxidative stress, and Wnt/β-catenin pathway activation. Hypoxia exposure induced CDX2 downregulation. CDX2 overexpression suppressed hypoxia-induced ROS generation, apoptosis rate, oxidative stress, and Wnt/β-catenin pathway activation. Moreover, CDX2 knockdown restores the inhibitory effects of si-β-catenin or NAC on hypoxia-induced activation of the Wnt/β-catenin pathway, apoptosis, and oxidative stress. In conclusion, our study suggests that CDX2 overexpression alleviates hypoxia-induced apoptosis and oxidative stress by suppression of ROS-mediated Wnt/β-catenin pathway in spermatogenic cells.

Effects of different ages on frozen semen quality and in vitro fertilization efficiency in Wannan black pigs

According to previous studies, the quality and fertilization rate of fresh sperm from boars of different ages were significantly different. However, the difference of freeze-thaw sperm quality and fertility in boars of different ages is unclear. In this study, boars of a Chinese native breed were assigned into two groups. Each group consisted of five boars aged aged either 2-3 years (young boars = YB) or 5-6 years (aging boars = AB) A total of 60 ejaculates for each group were collected and cryopreserved. Semen quality and in vitro fertility of post-thaw sperm was evaluated. The results showed that the concentration and motility of fresh sperm collected from AB were similar to YB, but their semen volume was higher than that in YB (p < 0.05). Frozen-thawed sperm of AB had lower viability than YB, and higher abnormal rate and reactive oxygen species (ROS) levels of YB (p < 0.05). There was no effect of the age on post-thaw sperm motility and time survival. Functional assessments indicated that increasing age markedly compromises the integrity of the sperm plasma membrane and acrosome, as well as mitochondrial functionality post-thaw, albeit without affecting DNA integrity. Furthermore, increasing age of boars reduces the ability of sperm to bind to the oocyte zona pellucida after thawing, delaying the time of the first embryo cleavage after fertilization. Finally, the early developmental efficiency of in vitro fertilized embryos progressing from 4-cell to blastocyst derived from post-thaw sperm in AB significantly decreased compared to those from YB (p < 0.05). Taken together, these results suggest that increasing age in boars impairs the quality and in vitro fertility of frozen thawed sperm.

Effects of MnTBAP on Porcine Semen Cryopreservation and Capacitation

Antioxidants protect cellular function and structure by neutralizing the oxidative stress caused by increased reactive oxygen species (ROS) during sperm freezing. Studies on cryopreservation using various antioxidants have demonstrated encouraging results. Many studies have used antioxidants to increase the efficiency of sperm freezing and to improve the success rate of artificial insemination and pregnancy. Manganese (III) tetrakis (4-benzoic acid) porphyrin chloride (MnTBAP) is a newly synthesized antioxidant with positive effects on sperm morphology and capacitation in humans, rams, and stallions. In this study, porcine semen was treated with 0, 50, 100, and 150 μM of MnTBAP based on a Tris-egg-yolk extender and frozen to determine whether MnTBAP can assist the status of sperm during cryopreservation. First, motility was assessed using the computer-assisted sperm analysis (CASA) system, with the 100 μM treatment group showing the highest motile rate (66.8%) compared with that of the other groups (control, 51.1%; 50 μM and 150 μM, 59.6%); therefore, the remaining analyses were conducted comparing the two groups (control vs. 100 μM group; p < 0.01). Second, fluorescence staining was applied to examine the control and 100 μM groups using fluorescence microscopy. The viability (41.7% vs. 62.4%) and the acrosome integrity (77.9% vs. 86.4%) differed significantly (p < 0.05). In addition, the mitochondrial membrane potential (MMP) was 46.5% vs. 51.9%; the fragmentation rate, estimated using the Sperm-sus-Halomax kit, was 63.4% vs. 57.4%; and the detected caspase activity was 30.1% vs. 22.9%. These tended to be higher in the treated group but did not differ significantly. Third, measurements using FACSLyric revealed that the 100 μM treatment group exhibited a state of elevated normal lipid arrangement within the plasma membrane and diminished levels of apoptosis and ROS (p < 0.01). We assessed the expression of genes relevant to antioxidant effectiveness using real-time RT-qPCR. Our findings indicated significant alterations in the expression levels of various mRNA species, with the exception of NOX5 (p < 0.05). Finally, the straws were dissolved and used to treat matured denuded oocytes to investigate the effect on fertilization and embryo development in vitro. The cleavage rate was (77.6% vs. 84.1%), and the blastocyst rate was 9.7% vs. 11.4% (p < 0.05). In conclusion, these results suggest that MnTBAP positively affected sperm freeze-thawing, improving the fertilization capacity, and leading to increased embryo development.

Advancements in Understanding and Enhancing Antioxidant-Mediated Sperm Cryopreservation in Small Ruminants: Challenges and Perspectives

Cryopreservation poses significant challenges to the preservation of sperm integrity and function, particularly in small ruminants where cryodamage is pronounced. This review explores the molecular mechanisms underlying sperm cryodamage and strategies for improving cryopreservation outcomes, with a focus on the role of antioxidants. Cryopreservation-induced alterations in proteins and RNA transcripts critical for sperm function, including motility, capacitation, fertilization, and embryo development, are discussed. Proteomic, transcriptomic, and epigenomic advancements have provided valuable insights into these mechanisms, offering potential biomarkers for predicting sperm freezability and enhancing cryopreservation strategies. Combining technologies such as mass spectrometry and flow cytometry allows for a comprehensive understanding of molecular and cellular changes induced by the freezing-thawing process. However, challenges remain in optimizing cryoprotectant formulations and antioxidant supplementation to improve post-thaw sperm fertility. Further research is needed to explore a wider range of novel cryoprotectants, antioxidants, and proteins for cryopreservation media, as well as to validate their efficacy in enhancing sperm viability and function. Additionally, investigations into the effects of cryopreservation on RNA transcripts and epigenetic factors in small ruminant species are warranted to advance our understanding of sperm preservation. Overall, this review highlights the importance of antioxidants in mitigating cryodamage and underscores the need for continued research to refine cryopreservation protocols and improve reproductive outcomes in small ruminants.

Sperm HSP70: may not be an age-dependent gene but is associated with field fertility in Bali bulls (Bos sondaicus)

This study aimed to analyze the characteristics of the HSP70 gene and protein in spermatozoa of Bali bulls of different age groups and to examine its potential as a biomarker determining bull fertility. This study used frozen semen produced from six Bali bulls divided into two groups based on age (≤ 9 years and ≥ 12 years). Parameters of frozen semen quality analyzed included sperm motility and kinetics using computer-assisted semen analysis, sperm morphological defects using Diff-Quick staining, acrosome integrity using FITC-PNA staining, and DNA fragmentation using acridine orange staining. HSP70 gene expression characterization was analyzed using qRT-PCR, and HSP70 protein abundance was analyzed using enzyme immunoassays. Fertility field data were obtained by analyzing the percentage conception rate for each bull based on the artificial insemination service data contained in the Indonesian-integrated system of the National Animal Health Information System (iSIKHNAS). The results showed significant differences (P<0.05) in total and progressive motility, morphological defects of the neck and midpiece, and tail of sperm, and acrosome integrity between the age groups of Bali bulls. HSP70 gene expression and protein abundance showed no significant differences (P>0.05) in different age groups. HSP70 gene expression correlated with fertility rate (P<0.05). Age affected several semen quality parameters but did not affect HSP70 gene expression and protein abundance. The HSP70 gene molecule could be a biomarker that determines the fertility of Bali bulls.

Supplementing Boar Diet with Nicotinamide Mononucleotide Improves Sperm Quality Probably through the Activation of the SIRT3 Signaling Pathway

Sperm quality is an important indicator to evaluate the reproduction ability of animals. Nicotinamide mononucleotide (NMN) participates in cell energy metabolism and reduces cell oxidative stress. However, the effect and regulatory mechanism of NMN on porcine sperm quality are still unknown. Here, 32 Landrace boars were randomly assigned to four groups (n = 8) and fed with different levels of NMN (0, 8, 16 or 32 mg/kg/d) for 9 weeks, and then serum and semen samples of the boars were collected to investigate the function and molecular mechanism of NMN in sperm quality. The results showed that the dietary NMN supplementation significantly increased sperm volume, density and motility (p < 0.05). Interestingly, NMN apparently improved the antioxidative indexes and increased the levels of testosterone (p < 0.05) in serum. Furthermore, NMN upregulated the protein levels of sirtuin 3 (SIRT3), antioxidation and oxidative phosphorylation (OXPHOS), but downregulated the protein levels of apoptosis in semen. Mechanically, NMN protected sperm from H2O2-induced oxidative stress and apoptosis through SIRT3 deacetylation. Importantly, the SIRT3-specific inhibitor 3-TYP attenuated the antioxidation and antiapoptosis of NMN in sperm. Therefore, NMN exerts antioxidation and antiapoptosis to improve boar sperm quality via the SIRT3 signaling pathway. Our findings suggest that NMN is a novel potential boar antioxidative feed additive to produce high-quality porcine semen.

Increases in computationally predicted deleterious variants of unknown significance and sperm mtDNA copy numbers may be associated with semen quality

BACKGROUND

Mitochondria are essential for sperm motility because they provide the energy required for the movement. Changes in sperm mtDNA, such as point mutations, large-scale deletions, or copy number variations, may interfere with ATP production and reduce sperm motility. However, it is not clear if changes in mtDNA are linked to semen quality.

OBJECTIVES

To explore the association between sperm mitochondrial DNA (mtDNA) changes and semen quality.

MATERIALS AND METHODS

Sixty-five oligo and/or astheno and/or terato patients (O/A/T) patients and 41 controls were recruited from couples undergoing assisted reproduction. Semen and blood samples were collected from the same individual on the day of oocyte retrieval to extract, isolate and purify mtDNA for next-generation sequencing. mtDNA copy numbers were assessed in 64 patient and 39 control sperm DNA samples using quantitative real-time PCR. The 4977 bp deletion was assessed in 20 patient and 20 control sperm DNA samples using polymerase chain reaction.

RESULTS

The mtDNA of patients was more likely to carry pathogenic variants or variants of unknown significance (VUSs) (P = 0.091) with higher heteroplasmy levels (P < 0.05) than that of controls. Interestingly, 33.85% of O/A/T patients (22 out of 65) lacked unique variants in their spermatozoa. but presented an exceptionally high mtDNA copy number (P < 0.0001). Moreover, we observed a decrease in the heteroplasmy level of common mtDNA variants shared by somatic and gamete cells (P < 0.0001) and the emergence of a very large number of de novo mtDNA variants with low-level heteroplasmy in spermatozoa.

DISCUSSION AND CONCLUSION

The increases in the number of computationally predicted deleterious VUS and mtDNA copies in spermatozoa may be associated with semen quality. Exposure to environmental mutation pressure that causes novel mtDNA variants with low-level heteroplasmy may occur during spermatogenesis. Furthermore, when a certain harmful threshold is reached, male germ cells may degrade mtDNA with mutations and replicate the correct mtDNA sequence to maintain the mitochondrial function in spermatozoa.

Effects of reactive oxygen species and mitochondrial dysfunction on reproductive aging

Mitochondria, the versatile organelles crucial for cellular and organismal viability, play a pivotal role in meeting the energy requirements of cells through the respiratory chain located in the inner mitochondrial membrane, concomitant with the generation of reactive oxygen species (ROS). A wealth of evidence derived from contemporary investigations on reproductive longevity strongly indicates that the aberrant elevation of ROS level constitutes a fundamental factor in hastening the aging process of reproductive systems which are responsible for transmission of DNA to future generations. Constant changes in redox status, with a pro-oxidant shift mainly through the mitochondrial generation of ROS, are linked to the modulation of physiological and pathological pathways in gametes and reproductive tissues. Furthermore, the quantity and quality of mitochondria essential to capacitation and fertilization are increasingly associated with reproductive aging. The article aims to provide current understanding of the contributions of ROS derived from mitochondrial respiration to the process of reproductive aging. Moreover, understanding the impact of mitochondrial dysfunction on both female and male fertility is conducive to finding therapeutic strategies to slow, prevent or reverse the process of gamete aging, and thereby increase reproductive longevity.

Dietary Patterns and Fertility

Diet has a key role in the reproductive axis both in males and females. This review aims to analyze the impacts of different dietary patterns on fertility. It appears that the Mediterranean diet has a predominantly protective role against infertility, while the Western diet seems to be a risk factor for infertility. Moreover, we focus attention also on dietary patterns in different countries of the World (Middle Eastern diet, Asian diet). In particular, when analyzing single nutrients, a diet rich in saturated fatty acids, cholesterol, animal proteins, and carbohydrates with high glycemic index is highly associated with male and female infertility. Finally, we evaluate the effects of vegetarian, vegan, and ketogenic diets on fertility, which seem to be still unclear. We believe that comprehension of the molecular mechanisms involved in infertility will lead to more effective and targeted treatments for infertile couples.

Bovine nucleoprotein transitions genes and protein abundance as valuable markers of sperm motility and the correlation with fertility

Bovine nucleoprotein transitions (TNPs), specifically TNP1 and TNP2, are essential molecules in sperm nucleus rich in arginine and lysine. These molecules act in the phase between histone expulsion and before incorporation of protamine in the spermatid nucleus. Therefore, this study aimed to analyze genes and protein abundance of TNP1 and TNP2 in sperm to determine the potential as motility markers and correlation with fertility in the field. An objective evaluation method, CASA-Sperm Vision, was used to separate 22 bulls into two groups (mg-A and mg-B) based on their increasing motility. Sperm quality parameters were also examined including velocity, mitochondrial membrane potential (MMP) by the JC-1 method, head defects using William staining, and DNA fragmentation by Halomax. TNPs genes abundance was performed using the RT-qPCR method, and the protein abundance was examined with the EIA approach. The fertility rate was also analyzed based on the conception rate generated from each bull in the field, with the data obtained from iSIKHNAS. The results showed that TNPs genes and protein abundance were significantly higher (P < 0.05) in mg-A compared to mg-B, followed by various sperm quality parameters and fertility rates (P < 0.05). Positive correlations were found in TNPs genes and protein abundance with motility, velocity, MMP, and fertility (P < 0.01). Meanwhile, a negative correlation (P < 0.01) was found between head defects and DNA fragmentation. These results showed the potential of TNPs as sperm motility markers and bull fertility.

Male Reproductive Toxicity of Antifouling Chemicals: Insights into Oxidative Stress-Induced Infertility and Molecular Mechanisms of Zinc Pyrithione (ZPT)

Zinc pyrithione (ZPT), a widely utilized industrial chemical, is recognized for its versatile properties, including antimicrobial, antibacterial, antifungal, and antifouling activities. Despite its widespread use, recent research has shed light on its toxicity, particularly towards the male reproductive system. While investigations into ZPT's impact on male reproduction have been conducted, most of the attention has been directed towards marine organisms. Notably, ZPT has been identified as a catalyst for oxidative stress, contributing to various indicators of male infertility, such as a reduced sperm count, impaired sperm motility, diminished testosterone levels, apoptosis, and degenerative changes in the testicular tissue. Furthermore, discussions surrounding ZPT's effects on DNA and cellular structures have emerged. Despite the abundance of information regarding reproductive toxicity, the molecular mechanisms underlying ZPT's detrimental effects on the male reproductive system remain poorly understood. This review focuses specifically on ZPT, delving into its reported toxicity on male reproduction, while also addressing the broader context by discussing other antifouling chemicals, and emphasizing the need for further exploration into its molecular mechanisms.

Pyrroloquinoline Quinone Improves Ram Sperm Quality through Its Antioxidative Ability during Storage at 4 °C

Sperm motility is an important factor in the migration of sperm from the uterus to the oviduct. During sperm preservation in vitro, sperm generates excessive ROS that damages its function. This study aims to investigate whether the addition of pyrroloquinoline quinone (PQQ) to the diluted medium could improve chilled ram sperm quality, and then elucidates the mechanism. Ram semen was diluted with Tris-citric acid-glucose (TCG) medium containing different doses of PQQ (0 nM, 10 nM, 100 nM, 1000 nM, 10,000 nM), and stored at 4 °C. Sperm motility patterns, plasma membrane integrity, acrosome integrity, mitochondrial membrane potential, reactive oxygen species (ROS) levels, malondialdehyde (MDA) levels, superoxide dismutase (SOD) activity, and ATP levels were measured after preservation. Furthermore, the expressions of NADH dehydrogenase 1 (MT-ND1) and NADH dehydrogenase 6 (MT-ND6) in sperm were also detected by western blotting. In addition, sperm capacitation and the ability of sperm to bind to the zona pellucina were also evaluated. It was observed that the addition of PQQ significantly (p < 0.05) improved ram sperm motility, membrane integrity, and acrosome integrity during preservation. The percentage of sperm with high mitochondrial membrane potential in the PQQ treatment group was much higher than that in the control. In addition, supplementation of PQQ also decreased the sperm MDA and ROS levels, while increasing ATP levels. Interestingly, the levels of MT-ND1 and MT-ND6 protein in sperm treated with PQQ were also higher than that of the control. Furthermore, the addition of 100 nM PQQ to the medium decreased ROS damage in MT-ND1 and MT-ND6 proteins. The addition of 100 nM PQQ significantly (p < 0.05) increased protein tyrosine phosphorylation in ram sperm after induced capacitation. Furthermore, the value of the sperm-zona pellucida binding capacity in the 100 nM PQQ treatment group was also much higher than that of the control. Overall, during chilled ram- sperm preservation, PQQ protected ram sperm quality by quenching the ROS levels to reduce ROS damage and maintain sperm mitochondrial function, and preserved the sperm's high ability of fertilization.

Assessment of reproductive toxicity of gold nanoparticles and its reversibility in male albino rats

Nanotechnology has become a trending area in science all over the world. Although gold nanoparticles (AuNPs) have been utilized widely in biomedical fields, potential toxicities may arise from their interactions with biological systems. The current study aimed at evaluating the toxic effects of AuNPs on the reproductive system of adult male albino rats and assessing the recovery probability. In this study, AuNPs (13 ± 4 nm in diameter) were synthesized, and the experimental work was conducted on 60 adult male albino rats divided into the following groups: control group (received deionized water daily intraperitoneally (IP) for 28 days), test group, and withdrawal groups I and II (received 570 μg/kg of 13 ± 4 nm AuNPs daily IP for 28 days). Withdrawal groups I and II were left for another 30 and 60 days without sacrification, respectively. The test group showed significant decreases in final body and absolute testicular weights, testosterone hormone level, sperm count and motility, and spermatogenesis score, as well as significant increase in the percentage of sperms of abnormal morphology compared to the control group, associated with significant light and electron microscopic histopathological changes. Partial improvement of all studied reproductive parameters was detected after one month of withdrawal in withdrawal group I, and significant improvement and reversibility of all these parameters were reported after two months of withdrawal in withdrawal group II. So, AuNPs induce male reproductive toxicity, which partially improves after one month of withdrawal and significantly improves and reverses after two months of withdrawal.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43188-023-00203-2.

Resveratrol Improves the Frozen-Thawed Ram Sperm Quality

Cryopreservation generates a substantial quantity of ROS in semen, leading to a decline in sperm quality and fertilization capacity. The objective of this study was to investigate the effects of resveratrol and its optimal concentration on ram sperm quality after cryopreservation. Ram semen was diluted with a freezing medium containing different concentrations of resveratrol (0, 25, 50, 75, and 100 μM). After thawing, various sperm parameters such as total motility, progressive motility, acrosome integrity, plasma membrane integrity, mitochondrial membrane potential, glutathione (GSH) content, glutathione synthase (GPx) activity, superoxide dismutase (SOD) activity, catalase (CAT) activity, lipid peroxidation (LPO) content, malondialdehyde (MDA) content, ROS level, SIRT1 level, DNA oxidative damage, and AMPK phosphorylation level were assessed. In addition, post-thaw sperm apoptosis was evaluated. Comparatively, the addition of resveratrol up to 75 μM significantly improved the sperm motility and sperm parameters of cryopreserved ram sperm. Specifically, 50 μM resveratrol demonstrated a notable enhancement in acrosome and plasma membrane integrity, antioxidant capacity, mitochondrial membrane potential, adenosine triphosphate (ATP) content, SIRT1 level, and AMPK phosphorylation levels compared to the control group (p < 0.05). It also significantly (p < 0.05) reduced the oxidative damage to sperm DNA. However, detrimental effects of resveratrol were observed at a concentration of 100 μM resveratrol. In conclusion, the addition of 50 μM resveratrol to the cryopreservation solution is optimal for enhancing the quality of cryopreserved ram sperm.

Antioxidants positively regulate obesity dependent circRNAs - sperm quality - functional axis

Obesity is a pathophysiological condition, dependent on body fat accumulation, that progressively induces systemic oxidative stress/inflammation leading to a set of associated clinical manifestations, including male infertility. CircRNAs, covalently closed RNA molecules, are key regulators of sperm quality. Recently, we have characterized a complete profile of high-fat diet (HFD) spermatic circRNA cargo, predicting paternal circRNA dependent networks (ceRNETs), potentially involved in sperm oxidative stress and motility anomalies. In the current work, using HFD C57BL6/J male mice, orally treated with a mix of bioactive molecules (vitamin C; vitamin B12; vitamin E; selenium-L-methionine; glutathione-GSH) for 4 weeks, a reversion of HFD phenotype was observed. In addition, the functional action of the proposed formulations on circRNA biogenesis was evaluated by assessing the endogenous spermatic FUS-dependent backsplicing machinery and related circRNA cargo. After that, spermatic viability and motility were also analyzed. Paternal ceRNETs, potentially involved in oxidative stress regulation and sperm motility defects, were identified and used to suggest that the beneficial action of the food supplements here conveniently formulated on sperm motility was likely due to the recovery of circRNA profile. Such a hypothesis was, then, verified by an in vitro assay.

Insulin desensitization and cell senescence induced by heat stress in pig testicular cell model

Thermostatic animals need to maintain a stable body temperature. A high-temperature environment can cause body temperature to exceed the range of tolerance of the organism, resulting in a heat stress response. The reproductive organs (such as the testes) are more sensitive to temperature due to their special anatomical location. However, to date, the effect of heat stress on the biological function of insulin in testicular cells has not been revealed. Therefore, the current study established a testis cell model to study the effect of heat stress on the biological activity of insulin. The results showed significant alterations in the insulin-induced intracellular signaling under heat stress conditions. Moreover, the IR-mediated intracellular signaling pathway was significantly downregulated under heat stress conditions. Further studies demonstrated that heat stress led to senescence of testicular cells by Sa-β-gal staining. Furthermore, the expression of senescence markers (p16 and p21) was increased under heat stress. In addition, heat stress was found to cause oxidative stress in testicular cells, which may be the underlying molecular mechanism by which heat stress changes the signaling properties of insulin. Collectively, the current study showed that heat stress caused alterations in insulin-induced intracellular signaling. Heat stress also induced testicular cell senescence.

Observational Cross-Sectional Study on Mediterranean Diet and Sperm Parameters

Infertility, affecting 15 to 25% of couples in the most developed countries, is recognized by the World Health Organization as a public health issue at a global level. Different causes are acknowledged to reduce fertility in both sexes. In particular, about 40-50% of cases recognize a male factor. Dietary habits and lifestyle are acknowledged to influence sperm quality and are therefore important modifiable factors in male reproductive health. Conditions such as overweight/obesity, impaired glucose metabolism and determinants of metabolic syndrome, together with unhealthy lifestyle behavior, i.e., smoking cigarettes and physical inactivity, are suggested to have a negative impact on male fertility. While individual elements and characteristics of the Western diet and habits are considered risk factors for male infertility, the Mediterranean diet (MD) seems to promote reproductive potential for improving sperm quality. It is also interesting to note that previous observational studies reported a positive correlation between the consumption of the single food classes of the MD pattern (i.e., vegetables and fruits, poultry, fish and seafood, whole grains, low-fat dairy products) and the quality of several sperm parameters. To evaluate the relationship between sperm parameters and MD adherence, we performed a cross-sectional study on the seminal data of 300 males (mean age 34.6 ± 9.1 years) who spontaneously referred to our center of reproductive medicine. The evaluation of adherence to MD was performed with a validated 14-point Mediterranean Diet Adherence Screener (MEDAS) questionnaire. Our findings showed that sperm parameters such as sperm count, motility, viability and normal morphology are significantly and positively correlated with MEDAS, independently of BMI and age. In addition, the application of an ROC curve on MEDAS value vs. seminal alterations identified 6.25 as the score threshold value below which altered sperm parameters were more likely to occur [AUC = 0.096 (CI: 0.059-0.133; p < 0.00)]. Therefore, adhering to the MD with at least a MEDAS score of 6.26 increases the probability of normozoospermia. Moreover, subjects who had a MEDAS value lower than 6.25 had an Odds Ratio of 6.28 (CI = 3.967-9.945) for having at least one altered sperm parameter compared to those who were more adherent to the MD. In conclusion, our findings show that a higher adherence to the MD is associated with better semen parameters, in particular in relation to sperm count, sperm concentration, typical sperm morphology, and sperm progressive motility.

Sperm Mitochondrial Content and Mitochondrial DNA to Nuclear DNA Ratio Are Associated with Body Mass Index and Progressive Motility

BACKGROUND

Mitochondrial dysfunction is a risk factor in the pathogenesis of metabolic disorders. According to the energy requirements, oxidative phosphorylation and the electron transport chain work together to produce ATP in sufficient quantities in the mitochondria of eukaryotic cells. Abnormal mitochondrial activity causes fat accumulation and insulin resistance as cells require a balance between the production of ATP by oxidative phosphorylation (OXPHOS) in the mitochondria and the dissipation of the proton gradient to reduce damage from reactive oxygen species (ROS). This study aims to explore the relationship between the mitochondrial content of sperm and the ratio of mitochondrial DNA to nuclear DNA in relation to body mass index (BMI) and how it may affect the progressive motility of sperm cell. Understanding the relationships between these important variables will help us better understand the possible mechanisms that could connect sperm motility and quality to BMI, as well as further our understanding of male fertility and reproductive health.

METHODS

Data were collected from 100 men who underwent IVF/ICSI at the University Hospital of Ioannina's IVF Unit in the Obstetrics and Gynecology Department. The body mass index (BMI) of the males tested was used to classify them as normal weight; overweight; and obese. Evaluations included sperm morphology; sperm count; sperm motility; and participant history.

RESULTS

In the group of men with normal BMI, both BMI and progressive motility displayed a statistically significant association (p < 0.05) with mitochondrial DNA content, relative mitochondrial DNA copy number, and the mtDNA/nDNA ratio. Similar to this, there was a positive association between BMI and motility in the groups of men who were overweight and obese, as well as between the expression of mitochondrial DNA and the mtDNA/nDNA ratio, with statistically significant differences (p < 0.05). There was not a statistically significant difference observed in the association between the relative mtDNA copy number and BMI or motility for the overweight group. Finally, the relative mtDNA copy number in the obese group was only associated with motility (p = 0.034) and not with BMI (p = 0.24).

CONCLUSIONS

We found that in all three groups, BMI and progressive motility exhibited comparable relationships with mitochondrial DNA expression and the mtDNA/nDNA ratio. However, only in the normal group and in the obese group, the relative mitochondrial DNA copy number showed a positive association with BMI and progressive motility.

Association between dietary total antioxidant capacity and semen quality among men attending an infertility clinic: a cross-sectional study

STUDY QUESTION

Is dietary non-enzymatic antioxidant capacity related to semen quality?

SUMMARY ANSWER

The only statistically significant association of semen quality parameters with dietary total antioxidant capacity (DTAC) detected was an inverse association between DTAC and ejaculate volume.

WHAT IS KNOWN ALREADY

Growing interest exists regarding the role of diet in influencing semen quality. While DTAC is linked to favorable health outcomes, its association with semen quality, especially among men attending infertility clinics, remains understudied.

STUDY DESIGN SIZE DURATION

This cross-sectional study was carried out between June and December of 2020. In total, 1715 participants were included in the final analysis.

PARTICIPANTS/MATERIALS SETTING METHODS

Men who attended an infertility clinic in China were enrolled. Experienced clinical technicians performed the semen analysis. The DTAC indices included the ferric-reducing ability of plasma, oxygen radical absorbance capacity, total reactive antioxidant potential, and Trolox equivalent antioxidant capacity. The quantile regression model was used for multivariate analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

After adjustment for a variety of confounding variables, a significant inverse association was identified between DTAC and ejaculate volume (βcontinuous FRAP = -0.015, 95% CI = -0.023, -0.006, βT3 vs T1 = -0.193, 95% CI = -0.379, -0.006, Ptrend = 0.007; βcontinuous TRAP = -0.019, 95% CI = -0.041, 0.002, βT3 vs T1 = -0.291, 95% CI = -0.469, -0.112, Ptrend = 0.002). The majority of DTAC indices have no statistically significant association with semen quality parameters.

LIMITATIONS REASONS FOR CAUTION

We cannot infer causality because of the nature of the cross-sectional study design. The robustness of the conclusion may be compromised by the exactness of non-enzymatic antioxidant capacity estimation.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings demonstrated no association between DTAC indices and semen quality parameters among men attending an infertility clinic, except for ejaculate volume. Even though our findings are mostly non-significant, they contribute novel knowledge to the field of study while also laying the groundwork for future well-designed studies.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the JieBangGuaShuai Project of Liaoning Province [grant number 2021JH1/10400050], the Clinical Research Cultivation Project of Shengjing Hospital [grant number M1590], and the Outstanding Scientific Fund of Shengjing Hospital [grant number M1150]. The sponsors had no role in study design, or in the collection, analysis, and interpretation of data, or in the writing of the report, or in the decision to submit the article for publication. There are no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Garden Cress Seed Oil Abrogates Testicular Oxidative Injury and NF-kB-Mediated Inflammation in Diabetic Mice

Diabetes mellitus is a metabolic disorder associated with various complications encompassing male reproductive dysfunction. The present study aimed to investigate the therapeutic potential of biologically active Lepidium sativum seed oil (LSO) against the testicular dysfunction associated with streptozotocin (STZ)-induced diabetes. Male adults (n = 24) were divided into four groups: control, LSO-administered, diabetic (D), and LSO-treated diabetic (D+LSO) groups. LSO was extracted from L. sativum seeds, and its chemical composition was determined using GC-MS. Serum testosterone levels, testicular enzymatic antioxidants (catalase (CAT) and superoxide dismutase (SOD)), an oxidative stress (OS) biomarker, malondialdehyde (MDA), pro-inflammatory markers (NF-kB, IL-1, IL-6, and TNF-α), and the expression level of NF-kB were assessed. In addition, histopathological changes were evaluated in testicular tissues. The results obtained showed that the chemical composition of LSO indicated its enrichment mainly with γ-tocopherol (62.1%), followed by 2-methylhexacosane (8.12%), butylated hydroxytoluene (8.04%), 10-Methylnonadecane (4.81%), and δ-tocopherol (3.91%). Moreover, LSO administration in the D+LSO mice significantly increased testosterone levels and ameliorated the observed testicular oxidative damage, inflammatory response, and reduced NF-kB expression compared to the diabetic mice. Biochemical and molecular analyses confirmed the histological results. In conclusion, LSO may prevent the progression of diabetes-induced impairment in the testes through inhibition of the OS- and NF-kB-mediated inflammatory response.

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.

Evaluation of Genistein as a Mitochondrial Modulator and Its Effects on Sperm Quality

Phytoestrogens, such as isoflavones, are bioactive compounds found in plants with defense and protection functions. In the human body, they simulate the behavior of the hormone estradiol and can modulate the function of the male hypothalamic-pituitary-gonadal axis. This study aims to describe the effects of genistein on sperm quality of Wistar rats (male/adult) after a short oral administration protocol (50 mg/day, for 5 days), focusing on mitochondrial function. No signs of toxicity were observed in the animals during the period. The testicular mass of rats from the genistein-treated group was lower than that from the control group. Isoflavone increased the number of viable Leydig and Sertoli cells, spermatogonia, and primary spermatocytes in the treated group. The rounded spermatid count was similar to the control group, and a decrease in elongated spermatids was observed in the treated group. Genistein treatment increased plasma testosterone levels in the treated group. To the best of our knowledge, this is the first report of an in vivo short protocol demonstrating that genistein administration stimulates the overall oxygen consumption in rat seminal samples. Therefore, genistein induced a pro-spermatogenesis effect, enhanced plasma testosterone levels, and increased oxygen consumption, improving sperm mitochondrial efficiency. Similar protocols can be explored in animal and human infertility issues.

SUMO1 and Defective Spermatozoa Correlate with Endogenous Hydrogen Peroxide and Live Birth Outcome in Intrauterine Insemination Cycles for Unexplained Infertility

This study aimed to investigate the correlation between hydrogen peroxide (H2O2), small ubiquitin-like modifier molecules (SUMO), and pregnancy outcomes in couples with unexplained infertility (UI) undergoing intrauterine insemination (IUI) treatment. We prospectively collected semen samples from 56 couples with UI and divided the spermatozoa into motile and immotile fractions by density gradient centrifugation (DSC). Immunofluorescence staining was used to examine the immunostaining and localization of nuclear pore complex (NPC), SUMO1, and SUMO2/3 in spermatozoa. We detected H2O2 levels by chemiluminescence methods. We found that H2O2 levels correlated with NPC (neck) (r = 0.400) and NPC (tail) (r = 0.473) in motile sperm fractions. In immotile fractions, H2O2 positively correlated with NPC (tail) (r = 0.431) and SUMO1 (neck) (r = 0.282). Furthermore, the positive NPC (tail) group had a significantly lower live birth rate than the negative NPC group (17.9% = 5/28 vs. 42.9% = 12/28). In conclusion, H2O2 positively correlated with SUMO1 (neck) and NPC (tail) in human spermatozoa. The DSC may partially eliminate defective spermatozoa (positive NPC staining); however, if defective spermatozoa remain in the motile fraction, this scenario is associated with a low live birth rate following IUI treatment.

Bovine sperm HSP-70 molecules: a potential cryo-tolerance marker associated with semen quality and fertility rate

Introduction

Freezability is the ability of sperm to maintain its vitality and quality from various stress during the cryopreservation process, which is very important for the success of fertilization in AI programs. Heat shock proteins (HSPs) are unique proteins induced in response to various stress, including excess reactive oxygen species (ROS) and oxidative damage to intracellular enzymes that can harm cells. This study aimed to analyze the potential of HSP-70 molecules in bovine sperm as a marker of freezability or cryo-tolerance, as well as its association with semen quality and fertility rate.

Methods

The classification of bulls is based on freezability (good freezability/GF and poor freezability/PF), which is obtained from the value of post-thaw viability using the SYBR-14/PI-flow cytometry. Semen quality assessed included sperm motility and kinetics (computer-assisted sperm analyses), plasma membrane integrity (HOS test), acrosome integrity (FITC-PNA), mitochondrial membrane (JC-1), and DNA damage (Halomax kit). The bull fertility rate assessment was analyzed based on the first service conception rate of each bull derived from data on the success of artificial insemination contained in the Indonesian-integrated National Animal Health Information System (iSIKHNAS). Gene expression levels of HSP-70 bovine sperm were performed using the RT-qPCR method. The protein abundance of HSP-70 bovine sperm was determined using the enzyme immunoassay (EIA) method.

Results

Bovine sperm HSP-70 molecules, at the gene and protein level, showed a higher abundance in GF (p < 0.05) than in PF bulls. The percentage of each parameter of frozen-thawed sperm quality was significantly higher in GF (p < 0.05) than in PF bulls. The HSP-70 molecules at the gene and protein levels were significantly positively correlated (p < 0.01) with the fertility rate. Furthermore, HSP-70 molecules were negatively associated (p < 0.01) with low mitochondrial membrane potential and sperm DNA damage and positively correlated (p < 0.01) with other frozen-thawed sperm quality parameters. The overall quality of frozen-thawed sperm was closely related (p < 0.01) to the fertility rate.

Conclusion

We may conclude that HSP-70 molecules in bovine sperm at the gene and protein level have the potential to be developed as a marker for cryo-tolerance or freezability, which may be utilized as a predictor of fertility and frozen-thawed sperm quality in bulls.

An Overview on Assay Methods to Quantify ROS and Enzymatic Antioxidants in Erythrocytes and Spermatozoa of Small Domestic Ruminants

The present review aims to provide an overview of the assay methods for the quantification of ROS and principal enzymatic antioxidants as biomarkers of oxidative stress in erythrocytes and spermatozoa of small domestic ruminants. A complete literature search was carried out in PubMed, Scopus and the World Wide Web using relevant keywords and focusing on the last five years (2018-2023). Among spectrophotometry, fluorometry and chemiluminescence, the most widely used method for ROS assay is fluorometry, probably because it allows to simultaneously assay several ROS, using different probes, with greater economic advantages. Regarding intracellular antioxidant enzymes, recent literature reports only spectrophotometric methods, many of which use commercial kits. The use of a less sensitive but cheapest method is suitable because both erythrocytes and spermatozoa samples are highly concentrated in domestic ruminant species. All methods considered in this review have been found to be appropriate; in general, the differences are related to their costs and sensitivity. Quantification of ROS and enzymatic antioxidant activity in erythrocytes and spermatozoa may find application in the study of the welfare and health status of small domestic ruminants for monitoring livestock production.

Evaluation of the Effect of Vitamin E on Reproductive Parameters in Morphine-Treated Male Mice

Background

Morphine is a narcotic pain reliever that is prescribed to reduce postoperative pain and can produce reactive oxygen species (ROS). Therefore, it can have negative effects on spermatogenesis and male fertility. Vitamin E is an effective antioxidant which plays an important role in membrane lipid peroxidation due to increased ROS. The present study aimed to evaluate the effects of vitamin E and morphine on sperm parameters, level of malondialdehyde (MDA), and diameter of seminiferous tubules in morphine-treated mice.

Methods

In this experimental study, 80 mice were divided into ten groups (n=8) including control, normal saline, vehicle, morphine, various doses of vitamin E (100, 200, 300 mg/kg), and morphine plus vitamin E (100, 200, 300 mg/kg) groups. The groups were followed up for 30 consecutive days. Sperm parameters, testis weight, the diameter of seminiferous tubules, and the level of MDA were analyzed and compared.

Findings

Data analysis showed seminal parameters decreased significantly (excluding sperm count) and there was an increase in the level of MDA in morphine-treated mice compared with the normal saline group (P<0.05). Administration of E100 to morphinetreated mice did not show a significant difference in the evaluated parameters compared with the morphine group. However, E200 and E300 significantly reduced MDA and improved sperm parameters (P≤0.05).

Conclusion

The results showed co-administration of vitamin E in high doses (200 & 300) could prevent the deleterious effects of morphine on some reproductive parameters and decrease the level of MDA in morphine-treated mice.

Male obesity is associated with sperm telomere shortening and aberrant mRNA expression of autophagy-related genes

BACKGROUND

Obesity is regarded a global public health crisis. It has been implicated in a variety of health problems, but when it comes to male fertility, how and to what extent obesity affects it are poorly understood. Accordingly, semen samples from 32 individuals with obesity (body mass index (BMI) ≥ 30 kg/m²) and 32 individuals with normal weight (BMI: 18.5-25 kg/m²) were obtained. Here, for the first time, we examined the association between obesity, relative sperm telomere length (STL) and autophagy-related mRNA levels such as Beclin1, AMPKa1, ULK1, BAX, and BCL2. Each group was also evaluated for conventional semen parameters, sperm apoptotic changes, DNA fragmentation index (DFI), sperm chromatin maturation, and reactive oxygen species (ROS) levels.

RESULTS

Based on our findings, there was a marked reduction in relative STL in individuals with obesity as compared to the normal-weight group. We also found a significant negative correlation between relative STL and age, BMI, DFI, percentage of sperm with immature chromatin, and intracellular ROS levels in patients with obesity. In the normal-weight group, relative STL was only negatively correlated with DFI and intracellular ROS levels. Regarding mRNA expression, there was considerable upregulation of Beclin1, ULK1, and BCL2 in the group with obesity compared to the normal-weight group. Obesity was also found to be associated with a considerable decline in semen volume, total sperm count, progressive motility, and viability in comparison to normal-weight individuals. Furthermore, obesity was associated with considerably higher percentages of DFI, sperm with immature chromatin, late-stage apoptosis, and elevated ROS levels.

CONCLUSION

According to our findings, obesity is associated with sperm telomere shortening and aberrant autophagy-related mRNA expression. It should be emphasized that telomere shortening in sperm may be an indirect consequence of obesity due to the oxidative stress associated with the condition. Nevertheless, further investigation is required for a more comprehensive understanding.

CYP19A1 TC/CC Polymorphism, along with Deletion of GSTM1 and GSTT1 Genes, Strongly Influences Female Infertility Risk

Oxidative stress has a fundamental role in the pathophysiology of various conditions, like infertility. This case-control study was performed to assess the potential role of CYP19A1, GSTM1, and GSTT1 in modifying individual predisposition to female infertility. Genotyping of 201 women with established infertility and 161 fertile female controls was performed, and statistical associations were analyzed. For carriers of GSTM1 null genotype along with CYP19A1 C allele, there is a significant association with female infertility risk (OR 7.023; 95% CI (3.627-13.601; p < 0.001), and, also for carriers of GSTT1 null genotype along with the CYP19A1 TC/CC genotype (OR 24.150; 95% CI (11.148-52.317; p < 0.001). A positive association with female infertility risk for carriers of the C allele in CYP19A1 and null genotypes in GTSM1 (OR 11.979; 95% CI (4.570-31.400; p < 0.001) or GSTT1 (OR 13.169; 95% CI (4.518-38.380; p < 0.001) was found. When both GSTs are deleted, the risk of developing female infertility is significant, independently of the CYP19A1 genotype; when all the presumed high-risk genotypes are present, we found a significant association with female infertility risk (OR 47,914; 95% CI (14,051-163,393; p < 0.001).

Proteomic analysis reveals the potential positive effects of Mito-TEMPO on ram sperm motility and fertility during cryopreservation

The aim of this study was to investigate the effects of mitochondria-targeted antioxidant Mito-TEMPO on the protein profile of ram sperm during cryopreservation and evaluate the cryoprotective roles of Mito-TEMPO on ram sperm quality and fertilization capacity. Semen collected from 8 Dorper rams was cryopreserved in TCG-egg yolk extender supplemented with various concentrations of Mito-TEMPO (0, 20, 40 and 60 μM). After thawing, sperm characteristics, antioxidant status and the abundance of hexose transporters (GLUT 3 and 8) were analyzed. The cervical artificial insemination (AI) was performed to evaluate the fertilization ability of cryopreserved ram sperm. The alterations of sperm proteomic profile between the control and MT₄₀ groups were determined using iTRAQ-coupled LC-MS. Supplementation with 40 μM of Mito-TEMPO resulted in the highest post-thaw sperm motility and kinematics. Sperm quality, antioxidant capacity and glucose transporter abundance of frozen-thawed ram sperm were elevated in the MT₄₀ group. The inclusion of 40 μM Mito-TEMPO in freezing extender also resulted in the higher pregnancy rate of ewes. A total of 457 proteins including 179 upregulated proteins and 278 downregulated proteins were defied as differentially expressed proteins (DEPs) using fold change (FC) > 1.2 with P < 0.05. Sixty-one DEPs with (FC > 1.5) were dramatically regulated by Mito-TEMPO. These DEPs are mainly involved in sperm motility, energy metabolism and capacitation. Our data suggest that the beneficial effects of Mito-TEMPO on sperm motility and fertility potential of cryopreserved ram semen are achieved by regulating sperm antioxidant capacity and sperm proteins related to energy metabolism and fertility.

Cuscuta chinensis flavonoids reducing oxidative stress of the improve sperm damage in bisphenol A exposed mice offspring

Bisphenol A (BPA) is a common environmental endocrine disruptor, and overexposure is a threat to male reproduction. Although studies have confirmed that BPA exposure causes a decrease in sperm quality in offspring, the dosage used, and the underlying mechanism is not clear. The purpose of this study is to investigate whether Cuscuta chinensis flavonoids (CCFs) can antagonize or alleviate BPA-induced reproductive injury by analyzing the processes associated with BPA's impairment of sperm quality. BPA and 40 mg/kg bw/day of CCFs were administered to the dams at gestation day (GD) 0.5-17.5. Testicles and serum of male mice are collected on postnatal day 56 (PND56), and spermatozoa are collected to detect relevant indicators. Our results showed that compared with the BPA group, CCFs could significantly increase the serum contents of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone (T) in males at PND 56, as well as the transcription levels of estrogen receptor alpha (ERα), steroidogenic acute regulatory protein (StAR) and Cytochrome P450 family 11, subfamily A, and member 1 (CYP11A1). CCFs also significantly inhibit the production of reactive oxygen species (ROS), reduce oxidative stress, increase mitochondrial membrane potential, and reduce sperm apoptosis. It also has a certain regulatory effect on sperm telomere length and mitochondrial DNA copy number. These results suggest that CCFs can increase reproductive hormone and receptor levels in adult males by regulating the expression of oxidative stress correlated factors, and ultimately mitigate the negative effects of BPA on sperm quality in male mice.

Novel Insights into circRNA Saga Coming from Spermatozoa and Epididymis of HFD Mice

Obesity is a pathophysiological disorder associated with adiposity accumulation, oxidative stress, and chronic inflammation state that is progressively increasing in younger population worldwide, negatively affecting male reproductive skills. An emerging topic in the field of male reproduction is circRNAs, covalently closed RNA molecules produced by backsplicing, actively involved in a successful spermatogenesis and in establishing high-quality sperm parameters. However, a direct correlation between obesity and impaired circRNA cargo in spermatozoa (SPZ) remains unclear. In the current work, using C57BL6/J male mice fed with a high-fat diet (HFD, 60% fat) as experimental model of oxidative stress, we investigated the impact of HFD on sperm morphology and motility as well as on spermatic circRNAs. We performed a complete dataset of spermatic circRNA content by a microarray strategy, and differentially expressed (DE)-circRNAs were identified. Using a circRNA/miRNA/target network (ceRNET) analysis, we identified circRNAs potentially involved in oxidative stress and sperm motility pathways. Interestingly, we demonstrated an enhanced skill of HFD sperm in backsplicing activity together with an inefficient epididymal circRNA biogenesis. Fused protein in sarcoma (FUS) and its ability to recruit quaking (QKI) could be involved in orchestrating such mechanism.

From oxidative imbalance to compromised standard sperm parameters: Toxicological aspect of phthalate esters on spermatozoa

The exponential rise in global male infertility and subfertility-related issues raises severe concern. One of the major contributors is phthalate esters, typical endocrine disruptors affecting millions of lives. The inevitable exposure to phthalates due to their universal application as plasticizers leaves the human population vulnerable to this silent threat. This review explicitly deals with the spermiotoxic effects of different phthalate esters on in vivo and in vitro models and on surveyed human populations to find the most plausible link between global usage of phthalates and poor sperm health. As the free radicals in spermatozoa are prerequisites for their standard structure and functioning, the precise regulation and phthalate-mediated impairment of pro-oxidant:anti-oxidant balance with subsequent loss of structural and functional integrity have also been critically discussed. Furthermore, we also provided future directives, which, if addressed, will fill the still-existing lacunae in phthalate-mediated male reproductive toxicity research.

Arsenic exposure and its implications in male fertility

Arsenic exposure is a global health concern. This toxic metalloid is ubiquitous in the environment and contaminates food and drinking water. Once ingested, it undergoes a complex metabolic process within the body, which contributes to its accumulation and reactivity. Arsenic toxicity stems from the induction of oxidative stress, inhibition of thiol-containing proteins, and mimicry of inorganic phosphates. Arsenic poisoning is associated with the development of reproductive disorders. In males, arsenic causes a reduction in testicular weight and alterations in steroidogenesis and spermatogenesis. Moreover, it reduces the number and quality of spermatozoa harvested from the cauda epididymis. The mitochondria are targets of arsenic toxicity because of the production of free radicals and their high content of cysteine-rich proteins and fatty acids. Mitochondrial dysfunction may contribute to reproductive disorders because this organelle is crucial for controlling testicular and epididymal events related to sperm production and maturation. All of these alterations mediated by arsenic exposure contribute to the failure of male reproductive competence by reducing gamete viability. This review describes the potential mechanisms of arsenic toxicity, its detrimental effects on male reproductive organs, and consequences on sperm fertility.

GRIM-19 in asthenozoospermia regulates GC-2 spd cell proliferation, apoptosis and migration

Asthenozoospermia (AZS) is a severe form of male infertility with no clear pathogenesis, despite numerous research efforts, there is no consensus on this. This study was to investigate the expression of gene-associated with retinoid-interferon-induced mortality 19 (GRIM-19) in the sperm of patients with asthenozoospermia and the regulation of GC-2 spd cell proliferation, apoptosis and migration. We analyzed the sperm samples from 82 asthenozoospermia and normal patients were collected in the First People's Hospital of Shangqiu and the First Affiliated Hospital of Zhengzhou University. Immunofluorescence, western blots and RT-qPCR analyses were used to verify the expressions of GRIM-19. MTT assays were used to assess cell proliferations, flow cytometry was performed to assess cell apoptosis, wound‑healing was performed to measure cell migration. Immunofluorescence showed that GRIM-19 is predominantly expressed in the sperm mid-piece, the mRNA expressions of GRIM-19 in sperms of the asthenozoospermia group were significantly low, relative to the normal group (OR 0.266; 95% CI = 0.081-0.868; P = 0.028). The protein expressions of GRIM-19 in sperms of the asthenozoospermia group were significantly lower than that of the normal group as well (GRIM-19/GAPDH: 0.827 ± 0.063 vs 0.458 ± 0.033; P < 0.001). GRIM-19 overexpression promotes GC-2 spd cell proliferation and migration and reduces apoptosis, while GRIM-19-silenced reduces GC-2 spd cell proliferation and migration and increased apoptosis. GRIM-19 is closely related to the occurrence of asthenozoospermia and promotes GC-2 spd cell proliferation and migration and reduces apoptosis.

Inhibition of Mitochondrial Uncoupling Proteins Arrests Human Spermatozoa Motility without Compromising Viability

Mitochondrial uncoupling proteins (UCPs) are central in the regulation of mitochondrial activity and reactive oxygen species (ROS) production. High oxidative stress is a major cause of male infertility; however, UCPs expression and function in human spermatozoa are still unknown. Herein, we aimed to assess the expression and function of the different homologs (UCP1-6) in human spermatozoa. For this purpose, we screened for the mRNA expression of all UCP homologs. Protein expression and immunolocalization of UCP1, UCP2, and UCP3 were also assessed. Highly motile spermatozoa were isolated from human normozoospermic seminal samples (n = 16) and incubated with genipin, an inhibitor of UCPs (0, 0.5, 5, and 50 µM) for 3 h at 37 °C. Viability and total motility were assessed. Mitochondrial membrane potential and ROS production were evaluated. Media were collected and the metabolic profile and antioxidant potential were analyzed by ¹H-NMR and FRAP, respectively. The expression of all UCP homologs (UCP1-6) mRNA by human spermatozoa is herein reported for the first time. UCP1-3 are predominant at the head equatorial segment, whereas UCP1 and UCP2 are also expressed at the spermatozoa midpiece, where mitochondria are located. The inhibition of UCPs by 50 µM genipin, resulting in the UCP3 inhibition, did not compromise sperm cell viability but resulted in irreversible total motility loss that persisted despite washing or incubation with theophylline, a cAMP activator. These effects were associated with decreased mitochondrial membrane potential and lactate production. No differences concerning UCP3 expression, however, were observed in spermatozoa from normozoospermic versus asthenozoospermic men (n = 6). The inhibition of UCPs did not increase ROS production, possibly due to the decreased mitochondrial activity and genipin antioxidant properties. In sum, UCPs are major regulators of human spermatozoa motility and metabolism. The discovery and characterization of UCPs' role in human spermatozoa can shed new light on spermatozoa ROS-related pathways and bioenergetics physiology.

Plantain-based diet decreases oxidative stress and inflammatory markers in the testes of rats exposed to atrazine

Exposure to the herbicide atrazine (ATZ) has deleterious effects on male fertility. This fact underscores the need for measures to protect against the detrimental impact of atrazine exposure on male fertility. The study assessed the protective effects of plantain-based diet (PBD) on rat testes exposed to ATZ by exploring oxid-inflammatory homeostasis. The study evaluated the preventive and therapeutic effects of PBD in a two-phased experiment. Male rats were randomized into seven groups for therapeutic model (Control, ATZ only, ATZ recovery, ATZ + 50% PBD, ATZ + 25% PBD, ATZ + 12.5% PBD and ATZ + quercetin-QUE) while the preventive model had ten groups (Control, ATZ, 50% PBD + ATZ, 25% PBD + ATZ, 12.5% PBD + ATZ and QUE + ATZ). The oxidative stress parameters (DNA fragmentation and MDA level), purinergic activity (ATPase), acetylcholine esterase, and inflammatory markers (NO level, MPO activity, and TNF-α) were increased while the Nrf2 levels were decreased by the ATZ treatment. However, the PBD was able to restore the oxido-inflammatory parameters in the rat testes. The chemical fingerprint of the diet revealed that the diets contained 16 bioactive compounds with quercetin being the most prominent compound. Overall, treatment with PBD was able to protect and prevent the toxicity caused by ATZ by modulating the redox and inflammatory status as well as purinergic activity in the rat testes.

Relationship of the levels of reactive oxygen species in the fertilization medium with the outcome of in vitro fertilization following brief incubation

Embryo selection in in vitro fertilization-embryo transfer (IVF-ET) mostly relies on morphological assessment using a conventional microscope or the time-lapse monitoring system, which is not comprehensive. Inappropriate levels of reactive oxygen species (ROS) in the fertilization medium may cause damage to gametes, eventually leading to adverse IVF outcomes. The present study aimed to identify the optimal oxidation-reduction level in the fertilization medium for IVF outcomes by measuring the static oxidation-reduction potential (sORP) using a highly accurate and sensitive MiOXSYS system. A total of 136 patients undergoing IVF following brief incubation were divided equally into 4 groups in this prospective cohort study. The sORP value in the fertilization medium was detected using the MiOXSYS system, and its relationship with IVF outcomes was analyzed. The primary outcome was pregnancy outcomes, including live birth rate (LBR), clinical pregnancy rate (CPR), biochemical pregnancy rate (BPR), and implantation rate (IR). The secondary outcome was embryo quality, including fertilization rate (FR), cleavage rate (CR), available embryo rate (AER), and good-quality embryo rate (GQER). Group II (sORP: 228.7-235.3 mV) showed a higher LBR, CPR, BPR, and IR compared with Group III (sORP: 235.4-242.7 mV), presented as follows: LBR (32.0% for Group II vs 3.6% for Group III, P = 0.033), CPR (32.0% for Group II vs 3.6% for Group III, P = 0.033), BPR (36.0% for Group II vs 3.6% for Group III, P = 0.019), and IR (31.3% for Group II vs 2.7% for Group III, P = 0.003). The FR in Groups I and II had lower significant differences compared with that in Groups III and IV (71.7% and 70.3% for Groups I and II vs 83.5% and 80.4% for Groups III and IV, P = 0.000). The GQER in Group I to Group IV was 32.7%, 37.4%, 26.5%, and 33.3%, respectively (P = 0.056). This study indicated that the sORP value in the fertilization medium might be a potential indicator of embryo quality and pregnancy outcome.

Sperm Mitochondria, the Driving Force Behind Human Spermatozoa Activities: Its Functions and Dysfunctions - A Narrative Review

Male infertility is a major issue, and numerous factors contribute to it. One of the important organelles involved in the functioning of human spermatozoa is mitochondria. There are 50-75 mitochondria helically arranged in mid-piece bearing one mitochondrial DNA each. Sperm mitochondria play a crucial role in sperm functions, including the energy production required for sperm motility and the production of reactive oxygen species, which in the physiological range helps in sperm maturation, capacitation, and acrosome reaction. It also plays a role in calcium signaling cascades, intrinsic apoptosis, and sperm hyperactivation. Any structural or functional dysfunction of sperm mitochondria results in increased production of reactive oxygen species and, a state of oxidative stress, decreased energy production, all leading to sperm DNA damage, impaired sperm motility and semen parameters, and reduced male fertility. Furthermore, human sperm mitochondrial DNA mutations can result in impaired sperm motility and parameters leading to male infertility. Numerous types of point mutations, deletions, and missense mutations have been identified in mtDNA that are linked with male infertility. Methods: Recent literature was searched from English language peer-reviewed journals from databases including PubMed, Scopus, EMBASE, Scholar, and Web of Science till September 2021. Search terms used were "Sperm mitochondria and male fertility", "Bioenergetics of sperm", "Sperm mitochondria and reactive oxygen species", "Sperm mitochondrial mutations and infertility". Conclusion: Sperm mitochondria is an important organelle involved in various functions of human spermatozoa and sperm mitochondrial DNA has emerged as one of the potent biomarkers of sperm quality and male fertility.

Varicocele, Functional Foods and Nutraceuticals: From Mechanisms of Action in Animal Models to Therapeutic Application

Varicocele is one of the main causes of infertility in men, thus representing an important clinical problem worldwide. Inflammation contributes mainly to its pathogenesis, even if the exact pathophysiological mechanisms that correlate varicocele and infertility are still unknown. In addition, oxidative stress, apoptosis, hypoxia, and scrotal hyperthermia seem to play important roles. So far, the treatment of varicocele and the care of the fertility-associated problems still represent an area of interest for researchers, although many advances have occurred over the past few years. Recent experimental animal studies, as well as the current epidemiological evidence in humans, demonstrated that many functional foods of natural origin and nutraceuticals that are particularly abundant in the Mediterranean diet showed anti-inflammatory effects in varicocele. The aim of the present narrative review is to mainly evaluate recent experimental animal studies regarding the molecular mechanisms of varicocele and the state of the art about possible therapeutic approaches. As the current literature demonstrates convincing associations between diet, food components and fertility, the rational intake of nutraceuticals, which are particularly abundant in foods typical of plant-based eating patterns, may be a reliable therapeutic supportive care against varicocele and, consequently, could be very useful in the cure of fertility-associated problems in patients.

Male infertility and somatic health - insights into lipid damage as a mechanistic link

Over the past decade, mounting evidence has shown an alarming association between male subfertility and poor somatic health, with substantial evidence supporting the increased incidence of oncological disease, cardiovascular disease, metabolic disorders and autoimmune diseases in men who have previously received a subfertility diagnosis. This paradigm is concerning, but might also provide a novel window for a crucial health reform in which the infertile phenotype could serve as an indication of potential pathological conditions. One of the major limiting factors in this association is the poor understanding of the molecular features that link infertility with comorbidities across the life course. Enzymes involved in the lipid oxidation process might provide novel clues to reconcile the mechanistic basis of infertility with incident pathological conditions. Building research capacity in this area is essential to enhance the early detection of disease states and provide crucial information about the disease risk of offspring conceived through assisted reproduction.

Statins and Male Fertility: Is There a Cause for Concern?

The well-known 3-hydroxyl 3-methyl glutaryl-Coenzyme A reductase inhibitors, called statins, have been the main medication used in the treatment of hypercholesterolemia and some cases of cardiovascular diseases. The effectiveness of this drug in controlling cholesterol production is impeccable, however, patients often complain of a variety of side effects, such as myalgia, muscle atrophy, and in some cases, rhabdomyolysis. Not only has the use of statins caused the aforementioned side effects, but they are also shown to cause testicular discomfort, erectile dysfunction, altered semen parameters, and modified steroid hormone production. These reported adverse effects on male fertility are not generally agreed upon, as some have shown the use to be beneficial. Hence, this makes the aftermath effect of statin use on male fertility debatable and controversial. The negative effects have been associated with imbalanced or reduced steroid hormones, which are necessary for proper spermatogenesis and other sexual functions. Meanwhile, the beneficial effects are related to statin's anti-inflammatory and cardioprotective properties. These contradictory findings are in part due to the different age of users, concentrations of statins, the type and duration of treatment, and the underlying disease and/or comorbidities. Therefore, the current study aims to analyze the literature and gather evidence as to the effects of statin on male sexual health and reproductive parameters, and subsequently give recommendations for the direction of future studies.

Male Infertility Coexists with Decreased Sperm Genomic Integrity and Oxidative Stress in Semen Irrespective of Leukocytospermia

Our research was designed to verify the relationship between male infertility, basic semen characteristics (with respect to detailed sperm morphology), sperm DNA fragmentation (SDF), oxidation-reduction potential in semen (ORP), and leukocytospermia. The obtained results showed that infertile groups (with or without leukocytospermia) had significantly lower basic semen characteristics and higher SDF, raw ORP, and static ORP (sORP) than fertile controls. The thresholds of 13% SDF (AUC = 0.733) and 1.40 sORP (AUC = 0.857) were predictive values for discriminating infertile from fertile men. In infertile groups, a higher prevalence and risk for >13% SDF and >1.40 sORP were revealed. Unexpectedly, leukocytospermic subjects had lower sORP, prevalence, and risk for >1.40 sORP than leukocytospermic-negative men. These groups did not differ in SDF and raw ORP. Both SDF and sORP negatively correlated with basic semen parameters but positively correlated with sperm head and midpiece defects. sORP positively correlated with sperm tail defects, immature sperm cells with excess residual cytoplasm, and SDF. In turn, raw ORP negatively correlated with sperm count but positively correlated with SDF and sORP. These findings indicate that (1) there is a relationship between male infertility, SDF, and OS in semen; (2) in infertile men, there is a clinically significant risk of SDF and OS irrespective of leukocytospermia; and (3) the assessment of SDF and oxidative stress should be independent of leukocytospermia.