Search Results (412)

Waterfowl semen cryopreservation technology is a key link in genetic resource conservation and artificial breeding, but poultry spermatozoa, due to their unique morphology and biochemical properties, are prone to oxidative stress during freezing, resulting in a significant decrease in vitality. In this study, we first used four different freezing procedures (P1–P4) to freeze duck semen and compared their effects on duck sperm quality. Then, the changes in antioxidant indexes in semen were monitored. The results showed that program P4 (initial 7 °C/min slow descent to −35 °C, followed by 60 °C/min rapid descent to −140 °C) was significantly better than the other programs (p < 0.05), and its post-freezing sperm vitality reached 71.41%, and the sperm motility was 51.73%. In the P1 and P3 groups, the sperm vitality was 65.56% and 53.41%, and the sperm motility was 46.99% and 31.76%, respectively. In terms of antioxidant indexes, compared with the fresh semen group (CK), the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-px) in the P2 group were significantly decreased (p < 0.05), while the activities of SOD and CAT in the P4 group showed no significant changes (p > 0.05) except that the activity of GSH-px was significantly decreased (p < 0.05). And the CAT and GSH-px activities in the P4 group were significantly higher than those in the P2 group (p < 0.05). The content of malondialdehyde (MDA) in the P2 group was significantly higher than that in the fresh semen group (p < 0.05), and there was no significant difference between the P2 group and the P4 group (p > 0.05). The total antioxidant capacity (T-AOC) content of the P2 and P4 groups was significantly lower than that of the fresh semen group (p < 0.05). The staged cooling strategy of P4 was effective in reducing the exposure time to the hypertonic environment by balancing intracellular dehydration and ice crystal inhibition, shortening the reactive oxygen species accumulation and alleviating oxidative stress injury. On the contrary, the multi-stage slow-down strategy of P2 exacerbated mitochondrial dysfunction and the oxidative stress cascade response due to prolonged cryogenic exposure time. The present study confirmed that the freezing procedure directly affects duck sperm quality by modulating the oxidative stress pathway and provides a theoretical basis for the standardization of duck semen cryopreservation technology. Full article

Varicocele is a common, potentially correctable condition associated with impaired male fertility. Despite being frequently encountered in clinical andrology, its pathophysiological mechanisms, diagnostic criteria, and therapeutic approaches remain areas of active investigation and debate. The authors conducted a comprehensive literature search, using the PubMed database, covering clinical studies, systematic reviews, meta-analyses, and current international guidelines from the past ten years. Emphasis was placed on studies investigating novel diagnostic modalities, therapeutic innovations, and prognostic markers. Emerging evidence supports the multifactorial pathophysiology of varicocele, involving oxidative stress, hypoxia, inflammatory pathways, and potential genetic predisposition. Biomarkers, including microRNAs, antisperm antibodies, and sperm DNA fragmentation, offer diagnostic and prognostic utility, though their routine clinical implementation requires further validation. Advances in imaging, such as shear wave elastography, may improve diagnostic accuracy. While microsurgical subinguinal varicocelectomy remains the gold standard, technological refinements and non-surgical alternatives are being explored. Indications for treatment have expanded to include selected cases of non-obstructive azoospermia, hypogonadism, and optimization for assisted reproduction, though high-level evidence is limited. Full article

Objectives: Parental exposure to tobacco smoke is a significant public health concern, with over 1.1 billion smokers worldwide. The aim of this systematic review was to evaluate the impact of maternal, paternal, and dual-parental cigarette smoke exposure on offspring reproductive health. Methods: Original human clinical and animal research studies were included; titles and abstracts were manually scanned for relevance to the effect of parental smoking on offspring reproductive outcomes (Date of search:18/03/2025). Results: This systematic review incorporates 30 studies identified from three databases (PubMed, Web of Science, and Scopus). The results indicate that male offspring exhibit reduced spermatogenic capacity, characterized by decreased testicular size, lower sperm count, and impaired hormonal biosynthesis, with reductions of 30–40% in sperm production. Dual-parental smoking exacerbates these effects, with sperm counts averaging 85 million per ml in human male offspring from dual-smoking households, compared to 111 million per ml in single-smoking households. Animal studies provide mechanistic insights, revealing reduced testis weight in nicotine-exposed male rats and increased oxidative stress in offspring. Conclusions: This review highlights the dose-dependent and sex-specific effects of smoking on the fertility of offspring and underscores the need for standardized protocols to enhance the consistency and comparability of future research in both human and animal studies. Full article

Mitochondria are central to energy production and redox regulation in spermatozoa, supporting key functions such as progressive motility, capacitation, and the acrosome reaction. These processes are essential for successful fertilization and embryo development. However, species-specific differences exist in the reliance on oxidative phosphorylation versus glycolysis. Mitochondria also generate reactive oxygen species, which at physiological levels aid in sperm function but can cause oxidative stress and damage when overproduced. Mitochondrial dysfunction and excessive ROS can impair membrane potential, induce apoptosis, and damage nuclear and mitochondrial DNA, ultimately compromising sperm quality. Sperm mitochondrial DNA is highly susceptible to mutations and deletions, contributing to reduced motility and fertility. Targeted antioxidant strategies have emerged as promising therapeutic interventions to mitigate oxidative damage. This article provides a comprehensive overview of mitochondrial regulation in spermatozoa, the consequences of redox imbalance, and the potential of mitochondria-targeted antioxidants to improve sperm function and male fertility outcomes. The paper aims to deepen our understanding of mitochondrial roles in sperm physiology and contribute to the advancement of strategies for addressing male infertility. Full article

Background: Oxidative stress is a critical factor contributing to male infertility, impairing spermatogonial stem cells (SSCs) and disrupting normal spermatogenesis. This study aimed to isolate and characterize human SSCs and to investigate oxidative stress-related gene expression, protein interaction networks, and developmental trajectories involved in SSC function. Methods: SSCs were enriched from human orchiectomy samples using CD49f-based magnetic-activated cell sorting (MACS) and laminin-binding matrix selection. Enriched cultures were assessed through morphological criteria and immunocytochemistry using VASA and SSEA4. Transcriptomic profiling was performed using microarray and single-cell RNA sequencing (scRNA-seq) to identify oxidative stress-related genes. Bioinformatic analyses included STRING-based protein–protein interaction (PPI) networks, FunRich enrichment, weighted gene co-expression network analysis (WGCNA), and predictive modeling using machine learning algorithms. Results: The enriched SSC populations displayed characteristic morphology, positive germline marker expression, and minimal fibroblast contamination. Microarray analysis revealed six significantly upregulated oxidative stress-related genes in SSCs—including CYB5R3 and NDUFA10—and three downregulated genes, such as TXN and SQLE, compared to fibroblasts. PPI and functional enrichment analyses highlighted tightly clustered gene networks involved in mitochondrial function, redox balance, and spermatogenesis. scRNA-seq data further confirmed stage-specific expression of antioxidant genes during spermatogenic differentiation, particularly in late germ cell stages. Among the machine learning models tested, logistic regression demonstrated the highest predictive accuracy for antioxidant gene expression, with an area under the curve (AUC) of 0.741. Protein oxidation was implicated as a major mechanism of oxidative damage, affecting sperm motility, metabolism, and acrosome integrity. Conclusion: This study identifies key oxidative stress-related genes and pathways in human SSCs that may regulate spermatogenesis and impact sperm function. These findings offer potential targets for future functional validation and therapeutic interventions, including antioxidant-based strategies to improve male fertility outcomes. Full article

Semen cryopreservation is associated with sperm vulnerability to oxidative stress and ice crystal-induced damage, adversely affecting in vitro fertilization (IVF) success. This study aimed to investigate the effects of freezing diluent supplemented with antioxidant limonin (Lim), myo-inositol (MYO), and the ice crystal formation inhibitor L-proline (LP) through sperm motility, morphological integrity, and antioxidant capacity. The Lim (150 mM), MYO (90 mM), and LP (100 mM) significantly ameliorated the quality of post-thaw sperm in Debao boar, and combined treatment of these agents significantly enhanced sperm motility, structural integrity, and antioxidant capacity compared with individual agents (p < 0.05). Notably, the combined use of these agents reduced glycerol concentration in the freezing diluent from 3% to 2%. Meanwhile, the integrity of the sperm plasma membrane, acrosome membrane, and mitochondrial membrane potential was significantly improved (p < 0.05), and the result of IVF revealed the total cell count of the blastocysts was also greater in the 2% glycerol group (p < 0.05). In conclusion, the newly developed freezing diluent for semen, by adding Lim (150 mM), MYO (90 mM), and LP (100 mM), can enhance the quality of frozen–thawed Debao boar sperm and reduce the concentration of glycerol from 3% to 2% as high concentrations of glycerol can impair the quality of thawed sperm and affect in vitro fertilization outcomes. In conclusion, the improved dilution solution formulated demonstrated efficacy in enhancing the quality of porcine spermatozoa following cryopreservation and subsequent thawing. Full article

Male infertility is a pathological condition that affects many subjects and for which a progressive increase in cases has been observed in recent years. The mechanisms underlying male reproductive system dysfunction are not fully understood and the specific drugs use has not produced optimal results. Therefore, the focus on developing new therapeutic options to prevent or treat this dysfunction is continuously growing. Defective sperm function has been associated with oxidative stress (OS) due to reactive oxygen species (ROS) excessive production. OS is related to mitochondrial dysfunction, lipid peroxidation, DNA damage and fragmentation, and ultimately sperm cell death. Many defense mechanisms to protect from ROS injuries have been developed; natural antioxidants, such as vitamin C and E are able to interact with oxidizing radicals, neutralizing them. Interestingly, resveratrol (RSV), a natural polyphenol with proven health-promoting actions, has been found to be an effective free radical scavenger in several in vitro and in vivo models, providing protection against OS. In this review, we discussed mechanisms related to the modulation of redox homeostasis in the testis and how the alteration of these processes can determine a damage in testicular function; particularly, we focused on the antioxidant properties of RSV that could give beneficial effects in preserving male fertility. Full article

Polystyrene microplastics (PS-MPs) released in the environment reportedly affect the reproduction of various organisms, induced oxidative stress and apoptosis, resulting in altered sperm parameters. In this in vitro study, we tested the cytotoxicity and genotoxicity of PS-MPs by exposing human semen samples to PS-MPs levels (105 and 210 μg/mL) for 30–60–90 min. Semen parameters, genome stability, sperm DNA fragmentation (SDF) and reactive oxygen species (ROS) production were analyzed before and after exposure. Moreover, we also evaluated the expression level of spermatozoa-specific expressed genes essential for the fusion with oocyte (DCST1, DCST2, IZUMO1, SPACA6, SOF1, and TMEM95). After PS-MP exposure, semen concentration and morphology did not differ, while sperm vitality and motility decreased in a time-dependent manner. In addition, sperm agglutination was observed in the groups exposed to both PS-MPs concentrations tested. A time- and concentration-dependent reduction in genomic stability, as well as increased SDF and ROS production, was also observed. Moreover, all investigated transcripts were down-regulated after PS-MP exposure. Our results confirm the oxidative stress-mediated genotoxicity and cytotoxicity of PS-MPs on human spermatozoa. The sperm agglutination observed after treatment could be due to the aggregation of PS-MPs already adhered to the sperm membranes, hindering sperm movement and fertilizing capability. Interestingly, the downregulation of genes required for sperm–oocyte fusion, resulting from data on the in vitro experimental system, suggests that PS-MP exposure may have implications for sperm functionality. While these findings highlight potential mechanisms of sperm dysfunction, further investigations using in vivo models are needed to determine their broader biological implications. Possible environmental and working exposure to pollutants should be considered during the counselling for male infertility. Full article

Infertility is a significant global health concern, and incorporating antioxidants into sperm preparation media is one strategy to enhance sperm quality and decrease infertility rates. This study aimed to investigate the phytochemical compounds of red cotton stamen extracts and their effects as antioxidants in improving the quality of bull frozen semen. Among the extracts, RCU contained the highest levels of total phenolics, total tannins, and total monomeric anthocyanins along with the strongest ABTS free radical scavenging activity and protein denaturation inhibition. Exposing sperm to FeSO₄-induced oxidative stress resulted in significantly reduced motility, viability, and normal morphology. However, treatment with RCD, RCU, and RCM improved these parameters. Additionally, the FeSO₄-induced group showed elevated levels of reactive oxygen species (ROS) and advanced glycation end products (AGEs) compared to the normal control, whereas all red cotton stamen extracts effectively reduced these levels. In conclusion, red cotton stamen extracts, rich in phenolic bioactive compounds, demonstrated strong free radical scavenging capacity and improved sperm motility, viability, and morphology by neutralizing free radicals and enhancing antioxidant defenses. These findings suggest that the red cotton stamen extracts, particularly RCD and RCU, offer benefits for sperm preservation. Full article

Background: Varicocele is a common condition involving the dilation of veins in the scrotum, often linked to male infertility and testicular dysfunction. This study aimed to elucidate the molecular effects of successful varicocele treatment on sperm proteomes following percutaneous sclero-embolization. Methods: High-resolution tandem mass spectrometry was performed for proteomic profiling of pooled sperm lysates from five patients exhibiting improved semen parameters before and after (3 and 6 months) varicocele sclero-embolization. Data were validated by Western blot analysis. Results: Seven proteins were found exclusively in varicocele patients before surgery—such as stathmin, IFT20, selenide, and ADAM21—linked to inflammation and oxidative stress. After sclero-embolization, 55 new proteins emerged, including antioxidant enzymes like selenoprotein P and GPX3. Thioredoxin (TXN) and peroxiredoxin (PRDX3) were upregulated, indicating restoration of key antioxidant pathways. Additionally, the downregulation of some histones and the autophagy-related protein ATG9A suggests a shift toward an improved chromatin organization and a healthier cellular environment post-treatment. Conclusions: Varicocele treatment that improves sperm quality and fertility parameters leads to significant proteome modulation. These changes include reduced oxidative stress and broadly restored sperm maturation. Despite the limited patient cohort analyzed, these preliminary findings provide valuable insights into how varicocele treatment might enhance male fertility and suggest potential biomarkers for improved male infertility treatment strategies. Full article

Sperm freezability exhibits marked individual variability, yet the mechanisms remain unclear. Using bulls as the experimental model, we integrated proteomic (sperm) and metabolomic (seminal plasma) analyses of high-freezability (HF) and control (CF) bulls to identify key biomarkers associated with sperm freezability. Post-thaw motility and membrane integrity were significantly higher in HF bulls (p < 0.05). Sperm proteome analysis revealed upregulated antioxidant proteins (PRDX2, GSTM4), heat shock proteins (HSP70, HSP90), and key enzymes in arginine and proline metabolism (PRODH, LAP3). Seminal plasma metabolomics revealed elevated spermine in HF bulls. Meanwhile, we found that spermine abundance was positively correlated with post-thaw motility, as well as with the expression levels of both PRODH and LAP3 (r > 0.6, p < 0.05). Functional validation demonstrated that 200 μM spermine supplementation in cryopreservation extenders enhanced post-thaw motility, kinematic parameters (VAP, VSL, VCL), membrane integrity, and acrosome integrity (p < 0.05). Concurrently, spermine enhanced antioxidant enzyme (SOD, CAT, GSH-Px) activity and reduced ROS and MDA levels (p < 0.05). Our study reveals a spermine-driven antioxidant network coordinating sperm–seminal plasma synergy during cryopreservation, offering novel strategies for semen freezing optimization. Full article

The conservation of small and genetically vulnerable brown bear populations, such as the Cantabrian subpopulation in Spain, depends on developing species-specific assisted reproductive technologies and genetic resource banks. However, the lack of standardized sperm collection and cryopreservation protocols hinders their application. This study provides the first comparative analysis of sperm quality and proteomic profiles from three different origins: epididymal, pre-ejaculated, and ejaculated. Sperm quality parameters —motility and kinetic, viability, apoptosis, and oxidative stress— and protein expression were assessed. Although yields were similar, marked differences were observed in sperm quality and protein profiles. Sixty-three proteins involved in metabolism, stress response, and oxidative balance were differentially expressed depending on sperm origin. Epididymal sperm showed the highest viability and motility, lowest apoptosis, and a proteomic profile indicative of active spermatogenesis and enhanced oxidative stress defense. In contrast, ejaculated sperm had increased oxidative stress and reduced expression of metabolic proteins, while pre-ejaculated sperm exhibited lower motility, likely due to urine contamination and mitochondrial protein alterations, despite comparable viability and apoptosis. These findings offer novel insights into brown bear sperm biology and highlight the importance of sperm origin in developing optimized assisted reproduction strategies, ultimately supporting ex situ conservation efforts for this species. Full article

Sperm membrane stability is a key factor in determining sperm viability and fertilization capability, with broad implications ranging from basic reproductive biology to livestock breeding practices. This comprehensive review examines the structural and functional mechanisms underlying sperm membrane integrity, including defensive barrier functions, potentiometric ion channel regulation, and motility modulation that collectively optimize sperm survival, motility, and fertilization potential. Environmental factors such as temperature fluctuations, abnormal pH levels (outside the optimal 7.2–8.2 range), pathological conditions, and hormonal imbalances can compromise membrane stability by inducing oxidative stress and protein denaturation. Key regulatory proteins, notably NPC2 for cholesterol homeostasis, Flotillin proteins for lipid raft organization, and Annexin V for membrane repair mechanisms, demonstrate essential roles in maintaining structural integrity. In livestock reproduction, membrane stability research facilitates the optimization of cryoprotectant formulations and freezing protocols, resulting in 15–25% improvements in post-thaw sperm survival rates and enhanced artificial insemination success. These findings provide valuable insights for advancing assisted reproductive technologies and improving reproductive efficiency in animal husbandry. Full article

Background: Doxorubicin (DOX) is a potent anti-cancer agent that is widely described in cancer treatment. However, its administration is often limited by its adverse effects, particularly its testicular toxicity, which can induce infertility in male patients. DOX-induced testicular damage is due to oxidative stress, apoptosis, and inflammation. Nanocurcumin (NCR) is a nano-formulated edition of curcumin with a higher therapeutic potential. NCR has demonstrated antioxidant and anti-inflammatory properties. Methods: This study is designed to inspect the potential validity of NCR on DOX-induced testicular damage in male rats. We used thirty-two Wistar albino rats (150–200 g) and divided them into four groups. NCR (80 mg/kg/ dissolved in 1% CMC) was given orally by oral gavage for 14 days. A single dose of DOX (15 mg/kg) (i.p.) was injected on the 7th day of the experiment. Results: DOX treatment reduced the sperm viability and motility rate, cellular antioxidants, and gonadal hormones; it led to higher levels of inflammatory mediators, necrosis, and sloughing in seminiferous tubules. Conversely, NCR treatment significantly alleviated these side effects by improving sperm count/motility and reducing sperm abnormalities. The testicular function recovery was likely driven by stimulating the cytoprotective SIRT1/NF-κB pathway, depressing the testicular level of oxidative indicators such as MDA, TNF-α, iNOS, IL-1β, and NO, and increasing levels of antioxidants such as GSH and SOD. In addition, NCR contradicted the apoptotic changes by downregulating the pro-apoptotic signals Bax and caspase-3, while inducing Bcl-2 upregulation. Moreover, NCR increased levels of gonadal hormones, attenuated histological abnormalities, and preserved testicular structure when compared with the DOX group. Conclusions: NCR treatment can effectively ameliorate DOX-induced testicular toxicity. Full article

Introduction: Infertility affects 15% of couples, with oxidative stress recognized as a key contributor to male infertility. Night-shift work, through circadian disruption, may exacerbate oxidative imbalance and impair reproductive function. This study investigates the impact of night-shift work on oxidative stress and semen quality and evaluates the potential benefits of antioxidant supplementation in this context. Materials and Methods: We retrospectively analysed 96 white-European men aged 18–45, seeking fertility assessment at a single academic centre. Participants were classified as day or night workers based on their shift schedule, and all underwent standardised clinical, hormonal, and semen evaluations. Oxidative stress was assessed using the d-ROMs test. A subgroup of 40 patients (20 per group) treated for 3 months with antioxidant supplementation (Drolessano) to evaluate changes in oxidative stress and semen parameters was also considered. Statistical comparisons were performed using non-parametric tests and logistic regression analyses. Results: Night-shift workers exhibit significantly higher oxidative stress levels compared to day workers (median D-ROMs values of 340 vs. 280 U.CARR, p = 0.01), and a greater proportion of men exceeding the oxidative stress threshold (74.4% vs. 24.4%, p = 0.01). Logistic regression confirmed night-shift work as an independent predictor of elevated oxidative stress (OR 2.1, p = 0.001), even after adjusting for age and smoking. Following three months of antioxidant supplementation with Drolessano, both groups experienced significant reductions in oxidative stress (all p < 0.01), but night workers showed a substantially greater decrease (mean change −58.5 vs. −15.4 U.CARR, p = 0.001). Improvements in semen quality, including sperm concentration, motility, and morphology, were also more pronounced in the night group after treatment. Conclusions: At baseline, night-shift workers had significantly higher oxidative stress than day workers, likely due to circadian disruption. Both groups improved after antioxidant treatment, but night workers showed a greater reduction in D-ROMs. This pilot study might suggest a potential benefit of antioxidant therapy particularly in night workers. Full article