Oxidative stress and male infertility

European Association of Urology Guidelines on Male Sexual and Reproductive Health: 2025 Update on Male Infertility

BACKGROUND AND OBJECTIVE

To present a summary of the updated 2025 European Association of Urology (EAU) Guidelines on Sexual and Reproductive Health (SRH) on male infertility, providing practical recommendations on the clinical work-up with a focus on diagnosis, treatment and follow-up.

METHODS

For the 2025 SRH guidelines, new and relevant evidence was identified, collated, and appraised via a structured assessment of the literature. Databases searched included Medline, EMBASE, and the Cochrane Libraries. Recommendations within the guidelines were developed by the panel to prioritise clinically important care decisions. The strength of each recommendation was determined according to a balance between desirable and undesirable consequences of alternative management strategies, the quality of the evidence (including the certainty of estimates), and the nature and variability of patient values and preferences.

KEY FINDINGS AND LIMITATIONS

Key recommendations emphasise the importance of a thorough urological assessment of all men seeking medical help for fertility problems to ensure appropriate treatment. The guidelines also stress the clinical relevance of a parallel investigation of the female partner during the diagnostic and management work-up of the infertile couple, to promote shared-decision making in terms of timing and therapeutic strategies. Furthermore, the guidelines recommend to counsel all infertile men and men with abnormal semen parameters on the associated health risks. Key changes in the male infertility guidelines for 2025 include: the addition of two new sections addressing exome sequencing and probiotic treatment; and significant update of the evidence base and recommendations for the diagnostic work-up of male infertility.

CONCLUSIONS AND CLINICAL IMPLICATIONS

This overview of the 2025 SHR guidelines offers valuable insights into the diagnosis, classification, treatment and follow-up of male factor infertility and are designed for effective integration into clinical practice.

Lycopene in male infertility

Male infertility is a major concern around the world, and efforts to find effective therapies to improve reproductive results are continuing. Factors such as genetics, hormonal disorders, lifestyle, and environmental pollutants have been mentioned as the pathoetiology of male infertility. The treatment of male infertility is far from optimal despite the recent signs of progress provided by assisted reproductive technology. Therefore, many efforts are being made to improve the therapeutical approaches to male infertility, which generally target the factors involved in the pathophysiology of the disease. Lycopene is a naturally occurring pigment belonging to the carotenoid family, which imparts a vibrant red color to various fruits and vegetables. It is widely assumed that lycopene may be an optimal option for the improvement of male fertility, however, the verification its therapeutic potential in male infertility has not been comprehensively reviewed. The study discusses the ability of lycopene to improve semen parameters, including sperm morphology, and motility which are important determinants of male reproductive health. Moreover, lycopene's capacity to regulate sex hormones, such as testosterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which play crucial roles in sperm production and maturation is explained. Additionally, lycopene effects on specific signaling pathways involved in male fertility, including prokineticin-2 (PROK2) and PI3K/Akt pathways, that influence sperm function are clarified. Furthermore, the impacts of lycopene as a potent antioxidant in defending against oxidative stress, a leading cause of male infertility, are presented. Overall, the results indicate that lycopene may have beneficial effects on improving male fertility by increasing sperm parameters, modulating sex hormones and signaling pathways, and providing antioxidant protection. Due to limited reports, additional clinical data is required to confirm the positive effects of lycopene on male fertility in humans.

Impact of chronic sleep deprivation on male reproductive health: Insights from testicular and epididymal responses in mice

BACKGROUND

Sleep deprivation (SD) can cause damage to the male reproductive system. However, the duration required for such damage and the specific sequence and severity of damage to the testis and epididymis remain unclear.

OBJECTIVE

To investigate the effects of different durations of SD on different parts of the testis and epididymis caput, corpus, and cauda.

METHODS

Adult ICR mice were randomly assigned to five groups: the SD group (SD for 18 h/day for 1, 2, 3, or 4 weeks), the SD + Vit E group (supplemented with Vit E 50 mg/kg/d during 4 weeks of SD, the SD+NS group (saline supplementation during 4 weeks of SD), the SD + RS group (5 weeks of recovery sleep after 4 weeks of SD), and a normal sleep control (Ctrl) group. Following the interventions, sperm parameters, testicular and epididymal histopathology, inflammatory response, and oxidative stress markers were compared between the groups.

RESULTS

Compared to the Ctrl group, the SD group showed a decrease in sperm motility and concentration from SD 2 W and SD 3 W, respectively. Decreases in sperm concentration and motility were more pronounced in the cauda compared to the caput and corpus. Pathological damage was less severe in the epididymis caput than in the corpus and cauda. After 4 weeks of SD, inflammation and oxidative stress increased in both testes and epididymis. Both sleep recovery and vitamin E supplementation showed significant improvements, though they did not fully reach the level of the Ctrl group.

CONCLUSION

Chronic SD for more than 2 weeks causes varying degrees of damage to the testis, epididymis caput, corpus, and cauda in male mice. This damage is not fully reversible after 5 weeks of sleep recovery and antioxidant stress treatment. These findings help us to identify and prevent SD damage to the male reproduction at an early stage.

Insulin‑like growth factor 2 in spermatogenesis dysfunction (Review)

Spermatogenesis dysfunction is characterized by abnormal morphology, destruction, atrophy of seminiferous tubules, blocked differentiation of spermatogenic cells, decreased sperm count and increased sperm abnormalities. Inflammation, oxidative stress, endoplasmic reticulum stress and obesity are important factors leading to spermatogenesis dysfunction. It has been demonstrated that insulin‑like growth factor 2 (IGF2) is closely related to the aforementioned factors. In the present review, the relationship between IGF2 and inflammation, oxidative stress, ER stress and obesity was investigated, providing theoretical and experimental evidence on the role of IGF2 in the prevention and treatment of spermatogenesis dysfunction of male infertility.

Allicin and hesperidin protect sperm production from environmental toxins in mice

This study investigates the protective effects of Allicin (A), a bioactive compound from garlic, and Hesperidin (HSD), a citrus flavonoid, against reproductive damage induced by para-nonylphenol (p-NP), an environmental pollutant, in mice. Fifty 8- to 10-week-old NMRI mice were divided into five groups: a control group, a group exposed to p-NP, and three groups treated with p-NP plus either Allicin, Hesperidin, or both. Treatments lasted for 35 days. Researchers analyzed sperm count, viability, motility, DNA damage, and morphology, alongside testicular parenchyma markers like antioxidant capacity (TAC), superoxide dismutase (SOD), glutathione peroxidase (GPx), and malondialdehyde (MDA) levels. Hormone levels (testosterone, LH, and FSH), testicular histopathology, apoptosis-related gene expression, and fertility indices were also evaluated. Results showed that mice treated with Allicin, Hesperidin, or both had reduced abnormal sperm morphology and DNA damage, with improvements in sperm motility, viability, and membrane integrity compared to the p-NP group. Antioxidant enzyme activities (TAC, SOD, GPx) and hormone levels increased, while MDA levels decreased, indicating reduced oxidative stress. Furthermore, expression of pro-apoptotic genes Bax and caspase-3 declined, while anti-apoptotic Bcl-2 expression rose. Treated mice demonstrated higher fertility indices and hormone levels. These findings suggest Allicin and Hesperidin mitigate p-NP-induced testicular damage by enhancing antioxidant defenses and regulating cell death pathways.

Molecular Mechanisms Contributing to the Impairment of Steroid Hormones, Sperm Characteristics, and Testicular Architecture in Male Rabbits After Chronic Exposure to Cadmium: Role of Gallic Acid and Selenium as Antioxidants

One hazardous material that occurs naturally in the environment and induces oxidative stress is cadmium (Cd). Epidemiological data revealed that exposure to cadmium in the workplace and environment might be linked to many illnesses and serious testicular injuries.

AIMS

It is taught that antioxidants can protect different organs against environmental toxic compounds. Therefore, the current investigation aims to show the role of antioxidants (gallic acid and selenium) in the protection against cadmium toxicity, including the architecture of the testes, semen properties, steroid hormones, protein expression of cytochrome P450 [CYP 19 and 11A1] contributing to the production of steroid hormones, and antioxidant enzyme activities, in male rabbits.

METHODS

Male rabbits were given cadmium orally three times/week [1 mg/kg BW] for twelve weeks. In addition, gallic acid (20 mg/kg) or selenium (1 mg/kg BW) was administered two hours before cadmium treatment. This investigation included a spectrophotometer, histopathology, and Western immunoblotting techniques.

RESULTS

Cadmium treatment significantly reduced sperm counts, testosterone, and estrogen levels after four, eight, and twelve weeks of treatment. In addition, after a 12-week treatment of rabbits with cadmium, the activity of 17β-hydroxysteroid dehydrogenase and antioxidant enzymes, including catalase, superoxide dismutase, glutathione reductase, glutathione peroxidase, and glutathione S-transferase, as well as the glutathione levels, were inhibited in the testes tissue. On the other hand, following cadmium treatment, rabbit's testes showed a discernible increase in free radical levels. Interestingly, the activity of antioxidant enzymes and level of free radicals were recovered in rabbits treated with gallic acid or selenium before cadmium treatment. In addition, after 12 weeks of cadmium treatment, the steroidogenic protein expressions of CYP 11A1 and CYP 19 were upregulated and downregulated in the testes, respectively. Interestingly, after pretreatment of rabbits with either gallic acid or selenium for two hours before cadmium administration, the downregulated CYP11A1 was restored to normal levels. In the histopathological investigation, immature spermatozoids and sloughed spermatogonium cells were observed in cadmium-treated rabbits' testes. On the other hand, pretreatments of rabbits with gallic acid or selenium mitigated and alleviated the adverse effects of cadmium on testes architecture and increased the production of healthy sperm.

CONCLUSIONS

The lower levels of steroid hormones could be due to the downregulation of CYP11A1, inhibition of 17β-hydroxysteroid dehydrogenase, antioxidant enzyme activities, and the induction of free radical levels. Furthermore, the pretreatment of rabbits with gallic acid or selenium mitigated the adverse effects of cadmium on the tissue architecture of testes and steroid hormone levels.

Zinc as a Modulator of Male Fertility: Interplay Between Lipid Metabolism, Oxidative Stress, and Sperm Function

Infertility is a multifaceted and pressing global health challenge, with male reproductive impairment playing a significant role in its overall burden. Zinc (Zn), a biologically indispensable trace element, is fundamental to spermatogenesis and overall male reproductive function. This narrative review explores the following aspects: (1) the mechanistic function of Zn in spermatogenesis, (2) the impact of oxidative stress on Zn status and male infertility, (3) the interplay between Zn and lipid metabolism in male reproductive physiology, (4) the relationship between Zn concentrations and semen parameters, and (5) the effects of Zn supplementation on sperm quality, alongside relevant institutional recommendations. The molecular pathways underlying Zn deficiency-induced enzymatic dysfunction, oxidative stress, and lipid homeostasis disruption remain partially elucidated, warranting further investigation into their interdependent effects on male infertility. While accumulating evidence suggests that Zn supplementation may have therapeutic potential in male infertility management, guidelines for its clinical application vary considerably across institutions and regions. To establish a clear and evidence-based framework for the function of Zn in male reproductive health, future research should prioritize determining of optimal Zn levels, the mechanistic links between Zn and lipid metabolism, and the long-term clinical outcomes of Zn supplementation in infertile populations.

Co-administration of atorvastatin with piperine induces reproductive toxicity in male Wistar rats through oxidative stress induction and downregulation of StAR, CYP11a1, 3βHSD and 17βHSD genes

Atorvastatin is a statin group of medicine that inhibits biosynthesis of cholesterol and mainly prescribed for treating cardiovascular diseases. Black pepper is a one of the mostly used spices that contains an alkaloid called piperine in its fruits which is known to cause male reproductive toxicity. Both atorvastatin and black pepper (piperine) are randomly consumed by the patients of chronic hyperlipidemia and it is important to know the synergistic effects of atorvastatin and piperine on male fertility parameters. Twenty rats were taken for the study and divided into four groups each containing five rats. Group I served as a control, group II animals are treated with atorvastatin (ATR) (8mg/kg BW), group III animals received piperine (PIP) (10mg/kg BW) and group IV animals were co-administered with piperine (10mg/kg BW) and atorvastatin (8mg/kg BW). All treatments were done by using water suspension of atorvastatin and piperine and using oral gavage for consecutive 28 days and thereafter assessed for gravimetric and histomorphometry analysis, sperm motility and morphology, ROS generation, anti-oxidant enzymes, serum testosterone quantification, qRTPCR (StAR, CYP11a1, 3βHSD and 17βHSD genes) and toluidine blue staining for analyzing chromatin integrity of spermatozoa. The results showed that co-administration of ATR+PIP significantly reduced body weight, changed in GSI also found. Activities of major two antioxidant enzymes (SOD and Catalase) were found to reduce whereas levels of TBARS and ROS in testicular tissues increased significantly. The study found that combined administration of atorvastatin and piperine negatively impacted male fertility potential, causing reproductive toxicity.

Protective effect of hydrogen-rich water on spermatogenesis in high-fat diet obese rats

Obesity can impair spermatogenesis by various mechanisms such as decreased sperm concentration and increased oxidative DNA damage. Hydrogen-rich water (HRW) possesses therapeutic antioxidant properties that may help offer protection to sperm. This study aimed to investigate the therapeutic potential of HRW on spermatogenesis dysfunction in rats with high-fat diet (HFD)-induced obesity. In this experiment, thirty male Wistar Albino rats were divided into three groups. 1) Control group: fed a normal diet, 2) Obese group: fed a HFD (45 % fat), and 3) HFD + HRW group: fed a high-fat diet and received HRW. HRW (1.5 mM) was administered orally every day. After 16 weeks, blood and tissue samples (testis and epididymis) were collected for biochemical and histopathological analysis. Serum LH, FSH and testosterone and oxidative and antioxidative markers, malondialdehyde (MDA), superoxide dismutase (SOD), and total thiol groups were measured in testis and epididymal tissues. The results showed that the HFD significantly increased food intake, body weight, and lee index, all of which were reduced in the HRW-treated obese group. Testis weight, sperm count, Serum LH and histological evaluation of testis including Sertoli and spermatogonia cell counts were significantly lower in the obese group but improved with HRW treatment. Additionally, HRW treatment increased the luminal diameter of seminiferous tubules, epididymal epithelia height, tissue SOD, and total thiol levels, while reducing MDA level in the testis. This study showed that administration of HRW can improve spermatogenesis in obese animals by reducing oxidative stress and ameliorating histological changes in the testis and epididymis, suggesting its potential benefits in combating high-fat diet-induced reproductive dysfunction.

Impact of the Environmental Endocrine Disruptor 4-Octylphenol on Reproductive Function in Pubertal Male Mice

4-Octylphenol, a major environmental degradation product of alkylphenols (Aps) used in industry, is an endocrine-disrupting chemical with significant estrogenic activity. It is one of the most toxic Aps, poorly biodegradable in the environment, and can accumulate in organisms through the food chain, thereby affecting the male reproductive system. In this study, the effect of 4-octylphenol on male reproductive health was analyzed. Male pubertal mice were exposed to 4-octylphenol at doses of 0, 1, 10, and 100 mg/kg once daily for 28 days. Our findings indicated that pubertal exposure to 4-octylphenol has significant negative effects on the male reproductive system. Pubertal mice exposed to 4-octylphenol exhibited dose-dependent reproductive toxicity. In the medium- and high-dose groups, a significant reduction in testicular mass, structural damage to the seminiferous tubules, increased oxidative stress and apoptosis within the testicular tissue, and a decline in sperm quality were observed. Additionally, autophagy processes in the testicular tissue, germ cell proliferation, and meiotic processes are inhibited. Serum testosterone and estradiol levels decreased, whereas oxidative stress levels in the testes and spermatozoa increased. In contrast, the low-dose group showed only a reduction in body weight, a decrease in motile sperm count, and mild oxidative stress in the testes without significant pathological changes in western blot experiments. These results indicate that 4-octylphenol exposure during puberty caused reproductive toxicity in male mice.

WTAP-mediated m6A modification of Hmgb2 contributes to spermatogenic damage induced by PM2.5 exposure

N6-methyladenosine (m6A) is extensively involved in complex spermatogenesis while being extremely sensitive to environmental exposure. Numerous studies have revealed the toxicity of fine particulate matter (PM2.5) to the male reproductive system, but the specific epigenetic mechanisms involved have been underexplored. Here, we investigated the effect of m6A modification on PM2.5-induced male reproductive impairment by establishing a real-time PM2.5-exposed mouse model and a GC-2spd cell model. PM2.5 exposure resulted in damage to the spermatogenic epithelium and mitochondrial abnormalities in spermatocytes and significantly reduced sperm motility in mice. Gene enrichment analyses of testicular tissue differential m6A modified genes were significantly enriched to spermatogenesis in the PM2.5-treated mice compared with the control group, and the expression of the methylase WTAP was markedly decreased after PM2.5 exposure. Moreover, PM2.5 exposure resulted in a significant reduction in the expression of the spermatogenesis-related gene Hmgb2, as well as in the level of the Hmgb2 m6A modification. Transcriptome sequencing and verification experiments suggested that Hmgb2 may regulate spermatocyte ATP levels. In addition, we demonstrated that the m6A methylase WTAP affects Hmgb2 mRNA stability via m6A modification. Our study provides new insights into PM2.5-induced damage to spermatogenesis and reduced sperm motility.

Contemporary Diagnostic Work-Up for Male Infertility: Emphasizing Comprehensive Baseline Assessment

Infertility is a prevalent issue affecting many couples during their reproductive years, with a significant number facing challenges in conceiving despite regular unprotected intercourse. Male factor infertility (MFI) contributes significantly to these cases, with a significant proportion of men lacking an identifiable etiology. As such, a thorough assessment of MFI has become increasingly vital for personalized management. This position paper from the Andrology team at IRCCS Ospedale San Raffaele emphasizes a comprehensive and individualized approach to MFI work-up, addressing the evolving challenges encountered in clinical practice. Our approach involves a thorough diagnostic work-up to identify the underlying causes of MFI, integrating insights from extensive literature review and our proprietary data. Our data demonstrates that an extensive diagnostic assessment allows us to identify at least one underlying cause of MFI in most infertile men. However, challenges persist in diagnosing less severe phenotypes with unclear etiology. We discuss the importance of individualized MFI work-up and its implications for developing rational therapeutic protocols. Lastly, this paper highlights the necessity for a personalized diagnostic assessment, addressing the daily clinical challenges and emphasizing tailored approaches to try to improve outcomes among couples seeking first medical help for infertility.

Stem cell exosomes: new hope and future potential for relieving liver fibrosis

Liver fibrosis is a chronic liver injury resulting from factors like viral hepatitis, autoimmune hepatitis, non-alcoholic steatohepatitis, fatty liver disease, and cholestatic liver disease. Liver transplantation is currently the gold standard for treating severe liver diseases. However, it is limited by a shortage of donor organs and the necessity for lifelong immunosuppressive therapy. Mesenchymal stem cells (MSCs) can differentiate into various liver cells and enhance liver function when transplanted into patients due to their differentiation and proliferation capabilities. Therefore, it can be used as an alternative therapy for treating liver diseases, especially for liver cirrhosis, liver failure, and liver transplant complications. However, due to the potential tumorigenic effects of MSCs, researchers are exploring a new approach to treating liver fibrosis using extracellular vesicles (exosomes) secreted by stem cells. Many studies show that exosomes released by stem cells can promote liver injury repair through various pathways, contributing to the treatment of liver fibrosis. In this review, we focus on the molecular mechanisms by which stem cell exosomes affect liver fibrosis through different pathways and their potential therapeutic targets. Additionally, we discuss the advantages of exosome therapy over stem cell therapy and the possible future directions of exosome research, including the prospects for clinical applications and the challenges to be overcome.

Detection of sperm DNA damage in male infertility patients and evaluation of Levocarnitine efficacy using sperm chromatin diffusion (SCD) and AI-DFI methods: a cross-sectional study

The objective of this study was to elucidate the relationship between sperm DNA damage and sperm parameters in male infertility patients and to assess the changes in sperm DNA fragmentation index before and after treatment with Levocarnitine in patients with asthenozoospermia and oligozoospermia. The results of 508 patients' semen samples tested between August 2021 and December 2022 in our Department of Urology and Reproductive Medicine were retrospectively analyzed. The 508 patients were divided into 3 groups: normal semen group (n = 181), asthenozoospermia group (n = 170), and oligozoospermia group (n = 157). Their sperm DNA integrity was evaluated using the sperm chromatin diffusion (SCD) method and an artificial Intelligence-based DNA fragmentation index (AI-DFI). The patients were divided into two groups based on the assessment of sperm DNA integrity: a sperm DNA damage group and a sperm DNA integrity group. The two groups were then compared in terms of sperm concentration, motility, viability, and the proportion of normal sperm morphology. Pearson's correlation coefficient analysis was employed to examine the relationship between sperm DNA damage and semen parameters. The results showed that sperm concentration, progressive motility, viability, and normal morphology rate were significantly lower in the DNA damaged group, and correlation analysis showed that the results of sperm DNA damage detection was negatively correlated with these semen parameters. And the DNA fragmentation index (DFI) was highest in the asthenozoospermia group, followed by the oligospermia group and the normal group, with significant differences between the groups (20.30 ± 2.85; 18.62 ± 2.42; 12.83 ± 2.13, P = 0.01). Treatment of patients in the group with sperm DNA damage with Levocarnitine oral solution was found to significantly improve sperm concentration, progressive motility, viability, normal morphology rate, and DFI results after its use (t = 7.265, 5.823, 7.750, 8.737, 8.355; P = 0.03, 0.02, 0.02, 0.03, 0.01). This study concludes that men with asthenozoospermia and oligozoospermia have a high DFI, and Levocarnitine is effective in reducing DNA damage and improving sperm quality, suggesting that Levocarnitine has potential for clinical use.

Yoga an integrated mind body intervention for improvement in quality of life in individuals with Alzheimer's disease and their caregivers

Background and objective

Alzheimer's disease (AD) presents profound challenges, significantly impairing quality of life (QOL) for patients and increasing the burden on caregivers. This study aims to investigate the effectiveness of a tailored 12-week yoga intervention in improving the quality of life for individuals with mild to moderate AD and reducing caregiver burden (CB).

Methods

This is yoga interventional study with healthy controls enrolled 30 participants (18 males, 12 females) diagnosed with mild to moderate AD by an expert neurologist. Participants were aged 60 years or older and were recruited from an old age home. A 12-week yoga program, including specific postures (asanas), pranayama (breathing exercises), and meditation, was conducted for 1 hour daily, 6 days a week. Neurocognitive assessments were performed pre- and post-intervention using the Geriatric Depression Scale (GDS), Montreal Cognitive Assessment (MoCA), and Caregiver Burden (CB) Scale. MoCA scores were analyzed across specific domains, including language, memory, attention, visuospatial ability, delayed recall, abstraction, and orientation.

Results

The intervention led to significant improvements in quality-of-life measures. GDS scores decreased from 8.36 ± 2.79 to 5.13 ± 3.07 (P < 0.01; 95% CI: -3.98 to -2.31), while MoCA total scores improved from 18.23 ± 4.90 to 21.10 ± 5.09 (P < 0.01; 95% CI: 2.17-3.89). Domain-specific MoCA scores also showed significant enhancements, particularly in language, attention, and delayed recall. Caregiver burden, measured using the CB Scale, demonstrated notable reductions following the intervention (P < 0.01; 95% CI: -2.54 to -1.23).

Conclusion

This study underscores the significant improvements in depression and cognitive function, and overall quality of life in individuals with mild to moderate AD. Additionally, the intervention alleviated caregiver burden, highlighting its potential as an effective mind-body approach for AD management.

Lifestyle and Environmental Factors Affecting Male Fertility, Individual Predisposition, Prevention, and Intervention

Current lifestyles bring about an increasing prevalence of unhealthy habits that can negatively affect male fertility. Cigarette smoking, alcohol intake, stress, inadequate physical activity, an unequilibrated diet leading to obesity, and use of mobile telephones and portable electronic devices can affect the male reproductive system through multiple mechanisms. Moreover, the modern man is often exposed to environmental factors independent of his will, such as air pollution, exposure to heat or toxicants in his workplace, or the presence of harmful chemicals in food, beverages, agricultural and industrial products, etc. The susceptibility to these factors depends on genetic and epigenetic predisposition, potentially present systemic disease and medication, and local affections of the genitourinary system. The multifaceted nature of both the causative factors and the susceptibility background makes the resulting fertility disturbance highly individual and variable among different men exposed to the same conditions. This paper critically reviews the current knowledge of different causative and susceptibility factors with a special attention to the molecular mechanisms of their action. Finally, strategies for the prevention of abnormalities due to lifestyle and environmental factors and available treatment modalities for already-present abnormalities are exposed.

Impact of physical activity on semen quality: a review of current evidence

A growing global trend indicates a decline in semen quality, with a lack of physical activity identified as one of the contributing factors. Exercise is medication, and numerous studies have explored its effects on semen quality. However, there is no consensus on the most effective type and intensity of exercise for improving semen quality, owing to inconsistent findings across studies. These discrepancies may be attributable to variations in study populations (e.g., healthy versus infertile individuals) and research methodologies (e.g., observational versus interventional studies). This paper reviews the existing literature from the databases PubMed, Web of Science, and Google Scholar, reclassifying articles on their subject and research designs to delineate the relationship between exercise and semen quality. It also summarizes the mechanisms through which exercise influences semen quality, including hormonal regulation, oxidative stress, and inflammatory factors.

Protective role of extracellular vesicles against oxidative DNA damage

BACKGROUND

Oxidative stress, a source of genotoxic damage, is often the underlying mechanism in many functional cell disorders. Extracellular vesicles (EVs) have been shown to be key regulators of cellular processes and may be involved in maintaining cellular redox balance. Herein, we aimed to develop a method to assess the effects of EVs on DNA oxidation using porcine seminal plasma extracellular vesicles (sEVs).

RESULTS

The technique was set using a cell-free plasmid DNA to avoid the bias generated by the uptake of sEVs by sperm cells, employing increasing concentrations of hydrogen peroxide (H2O2) that generate DNA single-strand breaks (SSBs). Because SSBs contain a free 3'-OH end that allow the extension through quantitative PCR, such extension -and therefore the SYBR intensity- showed to be proportional to the amount of SSB. In the next stage, H2O2 was co-incubated with two size-differentiated subpopulations (small and large) of permeabilized and non-permeabilized sEVs to assess whether the intravesicular content (IC) or the surface of sEVs protects the DNA from oxidative damage. Results obtained showed that the surface of small sEVs reduced the incidence of DNA SSBs (P < 0.05), whereas that of large sEVs had no impact on the generation of SSBs (P > 0.05). The IC showed no protective effect against DNA oxidation (P > 0.05).

CONCLUSIONS

Our results suggest that the surface of small sEVs, including the peripheral corona layer, may exert a protective function against alterations that are originated by oxidative mechanisms. In addition, our in vitro study opens path to detect, localize and quantify the protective effects against oxidation of extracellular vesicles derived from different fluids, elucidating their function in physiopathological states.

Association of oxidative balance score with incident cardiovascular disease in patients with type 2 diabetes: findings of the UK Biobank study

BACKGROUND & AIMS

To clarify how dietary and lifestyle factors work on diabetes-related cardiovascular disease (CVD), we investigated whether the increased risk of CVD in patients with type 2 diabetes mellitus (T2DM) could be offset by an increase in diet and/or lifestyle with antioxidant potential.

RESEARCH DESIGN AND METHODS

A total of 7,658 individuals from UK Biobank (UKB) with T2DM but no diagnosed CVD were included in this study. We screened combinations of 16 nutrients and/or 4 lifestyles to calculate the Oxidative Balance Score (OBS), dietary OBS (DOBS), and lifestyle OBS (LOBS). Cox proportional hazards (CPH) regression models and mediation statistical models were performed.

RESULTS

After adjusting for covariates, CPH regression models showed inverse associations between both OBS and LOBS and CVD. The highest tertile of LOBS was significantly associated with a lower risk of CVD compared to the lowest tertile, with hazard ratios and 95% CIs as follows: Atherosclerotic Cardiovascular Disease (ASCVD) 0.81 (0.68-0.97), Coronary Artery Disease (CAD) 0.79 (0.67-0.93), Atrial Fibrillation (AF) 0.56 (0.45-0.70) and CVD mortality 0.67(0.51-0.88). Correspondingly, the results of associations between the highest tertile of OBS and risks of CVDs above were ASCVD 0.80 (0.64-0.99), CAD 0.83(0.68-1.01), AF 0.73 (0.57-0.92) and CVD mortality 0.68 (0.50-0.92). No associations between DOBS and CVDs were observed [ASCVD 0.83 (0.66-1.05), CAD 0.86 (0.70-1.05), AF 0.77 (0.60-1.00), and CVD mortality 0.79 (0.57-1.10)]. These results were consistent in stratified analyses. Additionally, we identified a mediating role for C-reactive protein (CRP) and white blood cell count (WBC) in the observed relations, with indirect effect and mediation estimates as follows: CRP - 0.003 6.0% (OBS and CAD), -0.008 17.2%, -0.003 11.7%, and - 0.010 14.5% (OBS/DOBS/LOBS and CVD mortality); WBC - 0.006 14.3%, -0.006 12.6%, -0.006 13.4%, -0.005 23.3% (OBS and CVDs), -0.008 11.8%, -0.008 11.9%, -0.008 11.8%, and - 0.005 5.3% (LOBS and CVDs).

CONCLUSION

Sustained adherence to diets and lifestyles with high antioxidant potential may significantly reduce the risk of CVD in individuals with T2DM.

The combined effect between environmental exposure and oxidative stress-related susceptible gene polymorphisms on human semen quality

PURPOSE

The aim of the current study was to investigate the relationship between environmental factors and metabolic gene genotypes related to semen quality.

METHODS

A total of 341 men were recruited and classified into normal or abnormal semen quality groups according to the World Health Organization's 2010 criteria. Alcohol and tobacco use among men was self-reported. Pb (lead), As (arsenic), Ti (titanium), and Zn (zinc) metal elements in seminal plasma were measured using inductively coupled plasma mass spectrometry (ICP-MS). The ALDH2 rs671 and GSTP1 rs1695 polymorphism were detected using high-resolution melting (HRM) PCR.

RESULTS

Individual environmental factors, including smoking, drinking, and exposure to Pb, As, Ti, or Zn, did not significantly associate with the risk of semen abnormalities. The ALDH2 GA/AA mutation genotype increased the risk of semen abnormalities in smoking males (AOR = 1.27; 95% CI, 1.01-1.62) and in males with high seminal Ti levels (AOR = 1.36; 95% CI, 1.00-1.90). The GSTP1 rs1695 gene (GG/AG) mutation genotype exhibited a protective effect on semen quality in males who did not consume alcohol (AOR = 0.65; 95% CI, 0.51-0.85) or smoke (AOR = 0.79; 95% CI, 0.61-1.00), as well as in those with low Pb (AOR = 0.63; 95% CI, 0.46-0.88) and Ti (AOR = 0.64; 95% CI, 0.47-0.90) exposure.

CONCLUSIONS

The current study demonstrated that genetic and environmental factors interact with semen quality, and that men with the ALDH2 rs671A or GSTP1 rs1695A allele are susceptible to Ti-, alcohol-, and tobacco-induced semen quality abnormalities.

Polydatin, a derivative of resveratrol, ameliorates busulfan-induced oligozoospermia in mice by inhibiting NF-κB pathway activation and suppressing ferroptosis

Polydatin (PD), a glucoside derivative of resveratrol (RES), is extracted as a monomer compound from the dried rhizome of Polygonum cuspidatum. Our laboratory synthesized PD via the biotransformation of resveratrol. To assess the reproductive protective effects of PD, an oligozoospermia mouse model was induced by administering 30 mg/kg busulfan (BUS) via intraperitoneal injection. Initially, mice were categorized into groups based on PD concentrations of 10, 50, and 100 mg/kg. Subsequently, the optimal concentration of 10 mg/kg was ascertained based on testis weight and spermatological parameters. Additionally, a 10 mg/kg resveratrol group was included as a control. The findings revealed that exposure to BUS resulted in a reduction of testicular weight, diminished spermatogenic cells and epididymal sperm counts, increased sperm deformity, disordered testicular cytoskeleton, compromised blood-testis barrier integrity, and a significant decrease in serum sex hormone levels, notably testosterone. This resulted in decreased expression of androgen receptors and other testosterone-related proteins, increased levels of malondialdehyde and reactive oxygen species, and promoted testicular ferroptosis. However, PD could successfully reverse these injuries. High-throughput sequencing data demonstrated that polydatin significantly downregulated the expression of inflammatory and metabolic genes, including PRKCQ and CARD11. These proteins are pivotal in the activation of the NF-κB pathway during the inflammatory response. Molecular docking studies showed that PD could interact with PRKCQ and CARD11 to reduce the level of inflammation. Additionally, PD was shown to interact with the ferroptosis-promoting gene ACSL4, modulating ferroptosis. In summary, PD facilitates the reversal of BUS-induced oligozoospermia through the mitigation of oxidative stress and inflammation, the inhibition of ferroptosis, and the modulation of hormonal levels.

Correlation of IGF2 levels with sperm quality, inflammation, and DNA damage in infertile patients

ABSTRACT

Insulin-like growth factor 2 (IGF2) is a critical endocrine mediator implicated in male reproductive physiology. To investigate the correlation between IGF2 protein levels and various aspects of male infertility, specifically focusing on sperm quality, inflammation, and DNA damage, a cohort of 320 male participants was recruited from the Women's Hospital, Zhejiang University School of Medicine (Hangzhou, China) between 1 st January 2024 and 1 st March 2024. The relationship between IGF2 protein concentrations and sperm parameters was assessed, and Spearman correlation and linear regression analysis were employed to evaluate the independent associations between IGF2 protein levels and risk factors for infertility. Enzyme-linked immunosorbent assay (ELISA) was used to measure IGF2 protein levels in seminal plasma, alongside markers of inflammation (tumor necrosis factor-alpha [TNF-α] and interleukin-1β [IL-1β]). The relationship between seminal plasma IGF2 protein levels and DNA damage marker phosphorylated histone H2AX (γ-H2AX) was also explored. Our findings reveal that IGF2 protein expression decreased notably in patients with asthenospermia and teratospermia. Correlation analysis revealed nuanced associations between IGF2 protein levels and specific sperm parameters, and low IGF2 protein concentrations correlated with increased inflammation and DNA damage in sperm. The observed correlations between IGF2 protein levels and specific sperm parameters, along with its connection to inflammation and DNA damage, underscore the importance of IGF2 in the broader context of male reproductive health. These findings lay the groundwork for future research and potential therapeutic interventions targeting IGF2-related pathways to enhance male fertility.

Chronic psychological stress induces testicular oxidative stress affecting reproductive behavior in rats

The inhibitory effect of chronic psychological stress on reproductive behavior is widely recognized since long. However, the biological mechanisms underlying these effects, especially the cellular biology of the testicular cells, have not been fully investigated. This study aimed to investigate the effects of chronic psychological stress on rat reproductive behavior and its correlation with testicular cell damage and oxidative stress. The results showed that chronic psychological stress led to a decline in the preference scores of male rats for female rats and caused damage to the testicular tissue structure. Subcellular structures were particularly affected in the chronic psychological stress rats. Furthermore, the levels of MDA, NO, and NOS in testicular cells substantially increased under chronic psychological stress conditions. In conclusion, male reproductive behavioral disorders induced by chronic psychological stress are potentially linked to oxidative damage in testicular tissue.

Association between the composite dietary antioxidant index and risk of infertility: Evidence from NHANES 2013-2020 and a Mendelian randomization study

OBJECTIVE

The Composite Dietary Antioxidant Index (CDAI) measures the antioxidant capacity of the diet, which is believed to provide protection against various diseases, including depression, osteoporosis, and papillomavirus infection, by neutralizing harmful oxidative stress. However, the relationship between CDAI and infertility is not well understood. This research aims to explore the potential correlations between CDAI and the risk of infertility.

METHODS

This research harnessed data from the National Health and Nutrition Examination Survey (NHANES) to execute a cross-sectional analysis involving 8263 US women aged 20-45. Each participant was subjected to two distinct 24-h dietary recall interviews. We calculated the CDAI using average daily antioxidant intake. Infertility was assessed using a standardized questionnaire. The association between CDAI and infertility was examined using weighted multiple logistic regression models, while nonlinear correlations were explored through restricted cubic splines. To affirm the robustness of our findings, sensitivity and subgroup analyses were performed using unweighted logistic regression. Additionally, to ascertain the causal influence of circulating antioxidant levels on infertility, a two-sample univariable Mendelian randomization (MR) analysis was conducted, using the inverse variance weighted (IVW) method as the primary analytic approach.

RESULTS

Participants who were infertile exhibited lower CDAI levels compared to their fertile counterparts. When confounding variables were accounted for in the multivariate weighted logistic regression model, an inverse relationship was observed between CDAI and infertility, with the odds ratio for the highest versus lowest quartile being 0.55 (0.33-0.90, P = 0.02). However, the IVW method indicated that genetically predicted elevated levels of CDAI did not significantly correlate with infertility.

CONCLUSION

Cross-sectional observational studies indicate that antioxidants from diets might diminish infertility risks. However, findings from MR studies do not confirm a causal connection. Additional prospective research is required to elucidate this association further.

Ferroptosis emerges as the predominant form of regulated cell death in goat sperm cryopreservation

BACKGROUND

Freezing-induced sperm damage, often associated with oxidative stress, can result in regulated cell death. Given that oxidative stress can trigger various forms of regulated cell death, the prevailing form during sperm cryopreservation remains unknown. Our study aimed to investigate this issue using cashmere goats as a model.

RESULTS

We found a significant increase in lyso-phospholipids in frozen-thawed sperm suggested ferroptosis. Assessment of cryopreserved sperm, with or without prior treatment with ferroptosis or apoptosis inhibitors, demonstrated the significant efficacy of ferroptosis inhibitors in reducing freezing damage. This implicates ferroptosis as the primary form of regulated cell death induced during sperm cryopreservation. Additionally, the positive rate of transferrin receptor protein 1 was significantly lower in fresh live sperm (47.8%) than in thawed live sperm (71.5%), and the latter rate was lower than that in dead sperm (82.5%). By contrast, cleaved caspase-3 positivity showed no significant difference between fresh live sperm and thawed live sperm but was notably lower in thawed live sperm than in dead sperm.

CONCLUSIONS

Our findings establish ferroptosis as the dominant regulated cell death form during goat sperm cryopreservation, providing novel insights into freezing-induced sperm damage mechanisms. These findings have significant implications for optimizing cryopreservation protocols and enhancing sperm viability after freezing-thawing.

A review of antioxidant strategies to improve reproduction in aging male broiler breeders

As only 10% of the broiler breeder flock is roosters, their fertility is very important. The rooster sperm plasma membrane has high concentrations of polyunsaturated fatty acids that are sensitive to oxidative stress. Lipid peroxidation can change membrane structure, permeability, and fluidity, adversely affecting the acrosome reaction and fertility. Aging roosters have decreases in sexual behavior, serum androgen concentrations, sperm quantity and quality, and fertility. Low fertility in aging roosters is attributed to an imbalanced testicular oxidant-antioxidant system, with increased reactive oxygen species (ROS) damaging spermatogenic epithelium. However, antioxidant components can enhance antioxidant defenses in aging broiler breeder roosters. Protection against oxidative damage, particularly in the testes, improves reproductive hormone concentrations, testicular histology, sperm membrane function, and mitochondrial activity and thereby improves semen volume, sperm concentration, viability, motility, and sperm polyunsaturated fatty acid content, sperm-egg penetration, fertility, and reproductive performance. This review summarizes antioxidants that could improve fertility and reproductive performance and delay or prevent age-related declines in broiler breeder roosters, with benefits for poultry production.

Physical activity and male reproductive function

Fecundity is declining in humans, which is partly due to male infertility. Poor sperm parameters, the main contributors to male infertility, are associated with sedentary, unhealthy lifestyle and poor dietary habits. Long periods of sedentary work lead to visceral adiposity and persistently elevated scrotal temperatures, which adversely affect spermatogenesis. Apart from increasing scrotal temperatures, excessive visceral adiposity exacerbates adipocyte dysfunction with increased pro-inflammatory adipokine release, like leptin. These, together with the increased scrotal temperature, are responsible for the poor sperm quality. The importance of regular physical activity in male fertility remains a matter of debate, as not all forms of exercises have been found to benefit sperm function. Sperm parameters are, nevertheless, somewhat better in active than in sedentary men. It now appears that low-to-moderate intensity exercises are more beneficial for male reproductive health than high-intensity exercises, which have a negative effect on spermatozoa. Low-to-moderate intensity exercises, in general, improve the overall organ-system function in the body, improve the management of body weight and oxidative stress, consequently improving sperm parameters. The detrimental effects of high-intensity exercises on spermatozoa result from disruption in the hypothalamus-pituitary-gonadal-axis, raised testicular temperature and increased oxidative stress. It, therefore, seems that not all types of exercises are beneficial for male reproductive health. Although some low-to-moderate intensity exercises improve male reproductive function, there remains a need to identify the best form of low-to-moderate intensity exercises, particularly those that do not increase testicular temperature or oxidative stress, to help maintain normal body weight and male reproductive health.

From Hypoxia to Oxidative Stress: Antioxidants' Role to Reduce Male Reproductive Damage

Hypoxia is one of the main reasons causing male reproductive damage for people living in high altitude. Pathological evidences have been presented both in humans and animal models. Spermatogenesis disruption, worse sperm parameters, hormone disorder and erectile dysfunction are emblematic of male reproductive impairments brought by hypoxia. Among many mechanisms impairing male reproductive systems, oxidative stress is always a field of interest to explore. Although previous reviews have discussed about hypoxia or oxidative stress and antioxidants on male fertility respectively, no one has elucidated the concrete role of oxidative stress in hypoxia and correlating antioxidants that can ameliorate the negative effects. In this review, we firstly introduce hypoxia etiology and describe specific damage of hypoxia on male reproductive functions. Then, we emphasized interplays between hypoxia and oxidative stress as well as negative influences brought by oxidative stress. Finally, we listed antioxidants for oxidative stress and hypoxia-induced reproductive damage and discussed their controversial experimental effects for male infertility.

ASB1 engages with ELOB to facilitate SQOR ubiquitination and H2S homeostasis during spermiogenesis

Male infertility, frequently driven by oxidative stress, impacts half of infertile couples globally. Despite its significance, the precise mechanisms governing this process remain elusive. In this study, we demonstrate that ASB1, the substrate recognition subunit of a ubiquitin ligase, is highly expressed in the mouse testis. Mice lacking the Asb1 gene exhibit severe fertility impairment, characterized by oligoasthenoteratozoospermia. Subsequent investigations unveiled that Asb1 knockout (Asb1-KO) mice encountered excessive oxidative stress and decreased hydrogen sulfide (H2S) levels in their testes, and severe sperm DNA damage. Notably, the compromised fertility and sperm quality in Asb1-KO mice was significantly ameliorated by administering NaHS, a H2S donor. Mechanistically, ASB1 interacts with ELOB to induce the instability of sulfide-quinone oxidoreductase (SQOR) by enhancing its K48-linked ubiquitination on residues K207 and K344, consequently triggering proteasomal degradation. This process is crucial for preserving H2S homeostasis and redox balance. Overall, our findings offer valuable insights into the role of ASB1 during spermiogenesis and propose H2S supplementation as a promising therapeutic approach for oxidative stress-related male infertility.

Heat-not-burn technology affects plasma testosterone levels and markers of inflammation, oxidative stress in the testes of rats

Introduction

Heating tobacco products (HTPs) are advanced electronic cigarette models. Classified by the FDA as a modified-risk tobacco product and can be used as part of efforts to quit smoking. Using heat-not-burn (HnB) technology, these devices heat tobacco avoiding complete combustion. Although the levels of toxicants in the mainstream are significantly lower than those observed in tobacco smoke, some recent studies have raised concerns about potential health risks associated with their use, particularly regarding their effects on male gonadal function, which remain largely unexplored.

Methods

Adult male Sprague-Dawley rats were exposed, whole body, 5 days/week for 4 weeks to HnB mainstream.

Results

The expression of the cell cycle regulators Bax/Bcl-2 ratio is not affected, along with no changes in p-38. On the other hand, an increase in oxidative stress markers, including those associated with DNA damage, was observed in exposed animals, along with the induction of NF-kB dependent pro-inflammatory mediators: TNF-α, IL-1β, IL-6 and COX-2. Furthermore, inactivation of key androgenic enzymes, such as 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase, together with decreased testosterone synthesis suggest a potential impairment of male gonadal function.

Discussion

The results indicate that animals exposed to HnB smoke show higher levels of oxidative stress markers, including those associated with DNA damage, as well as higher levels of pro-inflammatory cytokines. The impairment of some androgenic key enzymes and those related to the activity of seminiferous epithelium, together with the decrease in testosterone levels, suggest an impairment of gonadal function through the alteration of some cellular pathways typically associated with tobacco consumption.

Oxidative-Stress-Mediated Epigenetic Dysregulation in Spermatogenesis: Implications for Male Infertility and Offspring Health

Male reproductive health is governed by an intricate interplay of genetic, epigenetic, and environmental factors. Epigenetic mechanisms-encompassing DNA methylation, histone modifications, and non-coding RNA activity-are crucial both for spermatogenesis and sperm maturation. However, oxidative stress, driven by excessive reactive oxygen species, disrupts these processes, leading to impaired sperm function and male infertility. This disruption extends to epigenetic modifications, resulting in abnormal gene expression and chromatin remodeling that compromise genomic integrity and fertilization potential. Importantly, oxidative-stress-induced epigenetic alterations can be inherited, affecting the health and fertility of offspring and future generations. This review investigates how oxidative stress influences epigenetic regulation in male reproduction by modifying DNA methylation, histone modifications, and non-coding RNAs, ultimately compromising spermatogenesis. Additionally, it discusses the transgenerational implications of these epigenetic disruptions and their potential role in hereditary infertility and disease predisposition. Understanding these mechanisms is vital for developing therapeutic strategies that mitigate oxidative damage and restore epigenetic homeostasis in the male germline. By integrating insights from molecular, clinical, and transgenerational research, this work emphasizes the need for targeted interventions to enhance male reproductive health and prevent adverse outcomes in progeny. Furthermore, elucidating the dose-response relationships between oxidative stress and epigenetic changes remains a critical research priority, informing personalized diagnostics and therapeutic interventions. In this context, future studies should adopt standardized markers of oxidative damage, robust clinical trials, and multi-omic approaches to capture the complexity of epigenetic regulation in spermatogenesis. Such rigorous investigations will ultimately reduce the risk of transgenerational disorders and optimize reproductive health outcomes.

Efficacy of Chlorogenic Acid in Treating Tripterygium Glycoside-Induced Asthenozoospermia in Rats and Its Possible Mechanisms

Tripterygium glycosides (TGs) are the most common form of traditional Chinese medicine, known as Tripterygium wilfordii Hook F (TWHF) [...].

ALDH2 plays a role in spermatogenesis and male fertility by regulating oxidative stress in mice

Spermatogenesis and sperm maturation are complex biological processes that involve intricate cellular and molecular interactions. The Aldh2 gene is involved in the metabolism of specific aldehydes generated by oxidative stress. Aldh2 is abundantly expressed in the testis and epididymis; however, the specific role of Aldh2 in regulating spermatogenesis and sperm maturation remains unclear. In the present study, we generated Aldh2 knockout (Aldh2-/-) mice by using CRISPR/Cas9 technology. Aldh2 gene knockout decreased the fertility of male mice. Compared to the control group mice, Aldh2-/- mice showed a significant decrease in the thickness of the seminiferous tubules and the number of germ cells. Further investigation revealed that the meiosis of spermatocytes and acrosome formation in sperm were disrupted in Aldh2-/- mice, leading to oligoasthenoteratozoospermia in male mice. However, the caput epididymis and cauda epididymis in Aldh2-/- mice showed identical proportions of morphologically abnormal sperm. Mechanistically, 4-hydroxynonenal, 3-nitro-L-tyrosine, and malondialdehyde levels were significantly elevated in both the testis and epididymis of Aldh2-/- mice, thus indicating increased oxidative stress in the reproductive system. Collectively, our findings demonstrate that Aldh2 plays a critical role in spermatogenesis by regulating oxidative stress in mice.

Micronucleus counts correlating with male infertility: a clinical analysis of chromosomal abnormalities and reproductive parameters

ABSTRACT

Investigating the correlation between micronucleus formation and male infertility has the potential to improve clinical diagnosis and deepen our understanding of pathological progression. Our study enrolled 2252 male patients whose semen was analyzed from March 2023 to July 2023. Their clinical data, including semen parameters and age, were also collected. Genetic analysis was used to determine whether the sex chromosome involved in male infertility was abnormal (including the increase, deletion, and translocation of the X and Y chromosomes), and subsequent semen analysis was conducted for clinical grouping purposes. The participants were categorized into five groups: normozoospermia, asthenozoospermia, oligozoospermia, oligoasthenozoospermia, and azoospermia. Patients were randomly selected for further study; 41 patients with normozoospermia were included in the control group and 117 patients with non-normozoospermia were included in the study group according to the proportions of all enrolled patients. Cytokinesis-block micronucleus (CBMN) screening was conducted through peripheral blood. Statistical analysis was used to determine the differences in micronuclei (MNi) among the groups and the relationships between MNi and clinical data. There was a significant increase in MNi in infertile men, including those with azoospermia, compared with normozoospermic patients, but there was no significant difference between the genetic and nongenetic groups in azoospermic men. The presence of MNi was associated with sperm concentration, progressive sperm motility, immotile spermatozoa, malformed spermatozoa, total sperm count, and total sperm motility. This study underscores the potential utility of MNi as a diagnostic tool and highlights the need for further research to elucidate the underlying mechanisms of male infertility.

Icariin targets PDE5A to regulate viability, DNA synthesis and DNA damage of spermatogonial stem cells and improves reproductive capacity

ABSTRACT

Icariin is a pure compound derived from Epimedium brevicornu Maxim, and it helps the regulation of male reproduction. Nevertheless, the role and underlying mechanisms of Icariin in mediating male germ cell development remain to be clarified. Here, we have demonstrated that Icariin promoted proliferation and DNA synthesis of mouse spermatogonial stem cells (SSCs). Furthermore, surface plasmon resonance iron (SPRi) and molecular docking (MOE) assays revealed that phosphodiesterase 5A (PDE5A) was an important target of Icariin in mouse SSCs. Mechanically, Icariin decreased the expression level of PDE5A. Interestingly, hydrogen peroxides (H2O2) enhanced the expression level of phosphorylation H2A.X (p-H2A.X), whereas Icariin diminished the expression level of p-H2A.X and DNA damage caused by H2O2 in mouse SSCs. Finally, our in vivo animal study indicated that Icariin protected male reproduction. Collectively, these results implicate that Icariin targets PDE5A to regulate mouse SSC viability and DNA damage and improves male reproductive capacity. This study thus sheds new insights into molecular mechanisms underlying the fate decisions of mammalian SSCs and offers a scientific basis for the clinical application of Icariin in male reproduction.

Abnormalities in mitochondrial energy metabolism induced by cryopreservation negatively affect goat sperm motility

The motility of sperm decreases following cryopreservation, which is closely associated with mitochondrial function. However, the alterations in mitochondrial metabolism after sperm freezing in goats remain unclear. This experiment aimed to investigate the impact of ultra-low temperature freezing on goat sperm's mitochondrial energy metabolism and its potential correlation with sperm motility. The results revealed that goat sperm exhibited mitochondrial vacuolization, reduced matrix density, and significantly decreased levels of high-membrane potential mitochondria and adenosine triphosphate content, accompanied by a substantial increase in reactive oxygen species levels, ultimately leading to a significant decline in sperm viability. Further investigations unveiled that energy-related differential metabolites (capric acid, creatine, and D-glucosamine-6-phosphate) and differential metabolites with antioxidant effects (saikosaponin A, probucol, and cholesterol sulfate) were significantly downregulated. In addition, the activity of key rate-limiting enzymes involved in very long-chain fatty acid biosynthesis and β-oxidation-specifically acetyl-CoA carboxylase, fatty acid synthase, and carnitine palmitoyltransferase I related to capric acid metabolism-was considerably reduced. Furthermore, supplementation of differential metabolite capric acid (500 μM) significantly enhanced the motility of frozen-thawed goat sperm. These findings indicated that the mitochondrial ultrastructure of goat sperm is damaged and energy metabolism becomes abnormal after cryopreservation, potentially affecting sperm viability. The addition of different metabolites such as capric acid to the freezing extender can alleviate the decrease in sperm motility induced by cryopreservation.

Epiberberine ameliorates MNNG-induced chronic atrophic gastritis by acting on the EGFR-IL33 axis

Chronic atrophic gastritis (CAG) is a prevalent form of chronic gastritis that presents with chronic inflammation of the gastric mucosa, localised gastric mucosal glandular atrophy and intestinal metaplasia. Despite the existence of diagnostic criteria, effective therapeutic strategies for this condition remain to be developed. The objective of this study was to examine the potential therapeutic benefits of epiberberine in mitigating MNNG-induced CAG and to elucidate the underlying mechanisms. MNNG was employed to establish a CAG mouse model and a GES-1 cell model, and EPI was observed to be efficacious in ameliorating the gastric mucosal injury and inflammatory infiltration induced by MNNG in the CAG model mice, a finding that was subsequently validated in the GES-1 model cells. Bioinformatics analysis indicated that EPI may exert a direct effect on EGFR, thereby regulating the expression of IL-33 and thereby achieving the therapeutic effect of CAG. This hypothesis was also validated by molecular docking prediction, CETSA, and overexpression of EGFR in GES-1 model cells, using EGFR agonists and inhibitors to further demonstrate that EPI may act as an antagonist supplement to EGFR for the treatment of CAG.

Perspective in the Mechanisms for Repairing Sperm DNA Damage

DNA damage in spermatozoa is a major cause of male infertility. It is also associated with adverse reproductive outcomes (including reduced fertilization rates, embryo quality and pregnancy rates, and higher rates of spontaneous miscarriage). The damage to sperm DNA occurs during the production and maturation of spermatozoa, as well as during their transit through the male reproductive tract. DNA damage repair typically occurs during spermatogenesis, oocytes after fertilization, and early embryonic development stages. The known mechanisms of sperm DNA repair mainly include nucleotide excision repair (NER), base excision repair (BER), mismatch repair (MMR), and double-strand break repair (DSBR). The most severe type of sperm DNA damage is double-strand break, and it will be repaired by DSBR, including homologous recombination (HR), classical non-homologous end joining (cNHEJ), alternative end joining (aEJ), and single-strand annealing (SSA). However, the precise mechanisms of DNA repair in spermatozoa remain incompletely understood. DNA repair-associated proteins are of great value in the repair of sperm DNA. Several repair-related proteins have been identified as playing critical roles in condensing chromatin, regulating transcription, repairing DNA damage, and regulating the cell cycle. It is noteworthy that XRCC4-like factor (XLF) and paralog of XRCC4 and XLF (PAXX) -mediated dimerization promote the processing of populated ends for cNHEJ repair, which suggests that XLF and PAXX have potential value in the mechanism of sperm DNA repair. This review summarizes the classic and potential repair mechanisms of sperm DNA damage, aiming to provide a perspective for further research on DNA damage repair mechanisms.

Assessing Seminal Plasma Malondialdehyde Acid as a Diagnostic Tool for Male Infertility: A Case-Control Study

AIM

The aim of this study was to assess the role of seminal Malondialdehyde Acid (MDA) in the diagnosis of male infertility.

BACKGROUND

Both male and female infertility is increasing all over the world.

OBJECTIVE

The purpose of this study was to assess the impact of seminal MDA levels on various semen parameters of healthy fertile men and men with infertility, and to know the efficacy of seminal MDA in the diagnosis of male infertility.

METHODS

This case-control study was carried out at the Department of Obstetrics and Gynaecology of a tertiary care center in rural Southern India over a period of two years. The study included 90 infertile men (≥21-50 years) having some pathology in semen reports as cases and 90 fertile men (having biological children) with normal semen reports as controls. Biochemical tests for MDA were performed using Human MDA Assay kits on 180 cryopreserved semen samples following the standard protocol. Results of seminal MDA levels were assessed among cases and controls and correlated with different semen parameters.

RESULTS

The mean±SD age for cases was 30.10 ± 4.75 years, and for controls, it was 29.79 ± 5.08 years. Of all the cases, 44 (48.9%) had asthenozoospermia, 22 (24.4%) had oligoasthenozoospermia, 14(15.6%) had oligozoospermia, and 10 (11.1%) had azoospermia. A statistically substantial variance was observed in mean values of MDA (1.03 ± 0.31 mmol/mL vs. 0.60 ± 0.14 mmol/mL; p =0.001) between fertile men and men with abnormal semen reports. A negative association was observed between semen MDA levels with sperm motility, concentration, and normal morphology in 180 participants. The sensitivity of MDA for male infertility prediction was 86.67% at 76.67% specificity, 78.79% positive predictive value, and 78.79% negative predictive value.

CONCLUSION

MDA has been found to be a promising biomarker for predicting male infertility. However, large sample sizes and prospective cohort studies are required to further confirm its predictive accuracy across various populations.

Unveiling the Emerging Role of Klotho: A Comprehensive Narrative Review of an Anti-aging Factor in Human Fertility

Klotho, an anti-aging protein, plays a vital role in diverse biological functions, such as regulating calcium and vitamin D levels, preventing chronic fibrosis, acting as an antioxidant and anti-inflammatory agent, safeguarding against cardiovascular and neurodegenerative conditions, as well as exerting anti-apoptotic, anti-senescence effects. Additionally, it contributes to metabolic processes associated with diabetes and exhibits anti-cancer properties. This protein is commonly expressed in organs, such as kidneys, brain, pancreas, parathyroid glands, ovaries, and testes. Recent research has highlighted its significance in human fertility. This narrative review provides insight into the involvement of Klotho protein in male and female fertility, as well as its potential role in managing human infertility in the future. In this study, a search was conducted on literature spanning from November 1997 to June 2024 across multiple databases, including PUBMED, SCOPUS, and Google Scholar, focusing on Klotho proteins. The search utilized keywords, such as "discovery of Klotho proteins," "Biological functions of Klotho," "Klotho in female fertility," "Klotho and PCOS," "Klotho and cryopreservation," and "Klotho in male infertility." Inclusion criteria comprised full-length original or review articles, as well as abstracts, discussing the role of Klotho protein in human fertility, published in English in various peer-reviewed journals. Exclusion criteria involved articles published in languages other than English. Hence, due to its anti-aging characteristics, Klotho protein presents potential roles in male and female fertility and holds promising prospects for reproductive medicine. Further, it holds the potential to become a valuable asset in addressing infertility concerns for both males and females.

Progress in the Study of TAp73 and Sperm Apoptosis

The study of the mechanism of oligoasthenospermia, which is a major cause of male infertility, has been the focus of research in the field of male reproduction. TAp73, a member of the p53 family of oncogenes, is endowed with tumor-suppressing activity due to its structural and functional homology with p53. It has been found that TAp73, plays a key role in spermatogenesis and maintaining male reproduction. When TAp73 is low-expressed or absent, the process of spermatogenesis is severely impaired, and mice deficient in TAp73 exhibit spermatogonial DNA damage, disturbed apical cytoplasmic specialization, and spermatocyte malformations resulting in reduced male fertility. Nevertheless, when TAp73 is overexpressed, it not only drives exogenous death receptors to regulate germ cell apoptosis, but also interacts with its various substrate proteins to promote the translocation of cytoplasmic Bax proteins to the mitochondria, resulting in the upregulation of the Bax/Bcl-2 ratio on the mitochondrial membrane and triggering a series of mitochondrial apoptotic effects. In this article, we will analyze the mechanism of TAp73 and sperm apoptosis, and elaborate the mechanism of TAp73 upregulation, exogenous apoptosis pathway and mitochondrial apoptosis pathway to systematically explain that the process of apoptosis induced by high expression of TAp73 is not fixed and single, but is interconnected, so as to provide a basis for the treatment of oligoasthenospermia and the research and development of new drugs using TAp73 as a target.

Role of Lipoic Acid in Testosterone Production in Males

Testosterone extends its impact beyond sexual function, playing a crucial role in shaping overall male health, including aspects such as muscle mass, bone density, mood regulation, and energy levels. Lipoic acid, a cofactor for specific enzymes, particularly dehydrogenases involved in cellular energy production, has been studied for its impact on testosterone. This comprehensive review systematically scoured PubMed and Scopus databases using the keywords "lipoic acid" and "testosterone." It encompassed all relevant English papers published from November 1971 to the present, including full texts and abstracts, along with research elucidating the biochemical mechanisms linking lipoic acid to testosterone. In summary, lipoic acid consistently restores testosterone levels, offering promise as an intervention in testicular health, especially in cases of testicular toxicity caused by various harmful agents. Its mechanisms encompass nitric oxide enhancement, fortification of testicular antioxidants, elevation of luteinizing hormone, enhancement of steroidogenesis, and the maintenance of energy production. These mechanisms underscore the therapeutic potential of lipoic acid for testicular health.

Effect of grape seed extract on doxorubicin-induced testicular and epididymal damage in rats

IntroductionDoxorubicin (DXR), a chemotherapeutic antibiotic, is widely used as an anticancer drug in clinics. Grape seed extract is known for its potent antioxidant properties. The aim of this study is to investigate the effect of high-antioxidant content Vitis vinifera L. seed extract against DXR-induced testicular and epididymal damage.Methods30 male rats were randomly divided into five groups with six animals in each group: Control, Sham, DXR (a single i.p. dose of 15 mg/kg), DXR + VIT (120 mg/kg VIT seed extract via gavage for 14 days and a single i.p. dose of DXR (15 mg/kg) on day 5, VIT (120 mg/kg VIT seed extract via gavage for 14 days). Animals were sacrificed under anesthesia 24 hours after the last drug administration, and blood, testis, and epididymis tissues were collected.ResultsTissues from the DXR group exhibited atrophic seminiferous tubules, Leydig cell degeneration, tunica albuginea and basal membrane thinning, immature spermatogenic cells, vascular congestion, epididymal atrophy, epithelial cell deletion, decreased sperm count, increased connective tissue, and absence of sperm in the lumen. Serum levels of interleukin 6 (IL-6), interleukin 1β (IL-1β), Tumor Necrosis Factor α (TNF-α), Total Oxidant Status (TOS), Total Antioxidant Status (TAS), and testosterone were increased in the DXR group, while interleukin 10 (IL-10) levels were decreased. The DXR + VIT group showed a near-recovery similar to the control.ConclusionDXR increased oxidative stress, apoptosis, and inflammation in the testis and epididymis, whereas VIT exhibited protective effects against these damages.

Simple and rapid multicolor sensor for seminal plasma ROS detection based on synergistic catalytic etching of gold nanobipyramids dopped agarose composite gel

Excessive reactive oxygen species (ROS) in seminal plasma can trigger male infertility. Therefore, the development of simple and rapid ROS detection methods is urgently needed, particularly for the early self-screening of preconception couples. Herein, a gold nanobipyramid (Au NBP)-based colorimetric hydrogel for convenient and fast ROS detection is described. In the hydrogel, Au NBP is etched efficiently by ROS under the synergistic effect of Fe2+and I-, which finally causes color variations. Besides, agarose gel with the function of molecular sieve enables the separation of biomacromolecules, improving the interference resistance of the system and the stability of Au NBP. This chemical sensor can complete all the tests within 20 min, covering two detection range of 10-125 μM at relative low H2O2 concentration and 125-1000 μM at relative high H2O2 concentration, with the detection limits of 1.76 μM and 12.10 μM (S/N = 3) respectively. Furthermore, via visual observation of the color variations, it allows the initial interpretation of ROS concentration without any additional equipment. We applied this device to the detection of ROS in clinical seminal plasma samples and obtained promising results, demonstrating its potential for rapid and convenient detection in clinical applications.

Selenium-Enriched Aspergillus oryzae A02 Enhances Testicular Antioxidant Capacity in Mice by Regulating Intestinal Microbiota and Serum Metabolite

Selenium (Se) is a trace element that is essential for health. Organic Se created by Se-enriched microorganisms has the characteristics of low toxicity, high bioavailability, and regulation of physiological functions. Here, the regulatory effect of Se-enriched Aspergillus oryzae A02 on the reproductive function of male mice and its potential molecular mechanism was studied. Specifically, twenty-four male mice were randomly divided into a control group and a Se-enriched A. oryzae A02 (Nano-Se) (daily gavage of 0.5 mg/kg, dissolved in saline) for an 8-week experiment. The results showed that Nano-Se intervention did not affect body weight and testicular index, but increased sperm concentration and seminiferous epithelium height in experimental mice, indicating that Nano-Se has the potential to improve the reproductive performance of male mice. Mechanistically, Nano-Se intervention increased the levels of antioxidant-related indicators catalase (CAT) and glutathione peroxidase (GSH-Px) in mouse serum, and increased the relative mRNA expression of GSH-Px, heme oxygenase-1 (HO-1), and NADPH quinine oxidoreductase-1 (NQO-1) in testicular tissues. We identified 9,10,13-trihydroxyoctadecenoic acids (TriHOMEs), stearidonic acid and selenomethionine linked with alpha-linolenic acid metabolism, selenocompound metabolism, folate biosynthesis, ubiquinone, and other terpenoid-quinone biosynthesis and biosynthesis of cofactors. In addition, Nano-Se did not influence the fecal bacterial alpha and beta diversity (P > 0.05), but increased the abundance of the Actinobacteriota and Proteobacteria phyla and the Staphylococcus and Corynebacterium genera, and lowered the abundance of the Bacteroidota phylum and the Lactobacillus and norank_f_Muribaculaceae genera. Nano-Se is considered a novel and promising nutritional regulator to improve reproductive function.

Cyberpharmacology uncover the mechanism of the total Rhizoma Coptidis extracts ameliorate chronic atrophic gastritis

ETHNOPHARMACOLOGICAL RELEVANCE

Characterized by inflammation of the gastric mucosa, atrophy of gastric gland cells, and intestinal metaplasia, Chronic Atrophic Gastritis (CAG) is a precancerous lesion disease. In traditional Chinese medicine, Rhizoma Coptidis (RC) is extensively used for treating gastrointestinal disorders, mainly because RC alkaloids-based extracts are the main active pharmaceutical ingredients. Total Rhizoma Coptidis extracts (TRCE) is a mixture of Rhizoma Coptidis extracts from Rhizoma Coptidis with alkaloids as the main components. However, the efficacy and mechanism of TRCE on CAG need further study.

AIM OF THE STUDY

To explore the therapeutic effect and underlying mechanisms of action of TRCE on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced chronic atrophic gastritis (CAG) using network pharmacological analysis.

MATERIALS AND METHODS

The amelioration effect of TRCE on CAG was evaluated in MNNG-induced CAG mice. The pathological severity of the mice was evaluated through H&E staining. Detection of gastric mucosal parietal cell loss was conducted using immunofluorescence staining, and serum indices were measured using ELISA. Additionally, the active compounds and drug targets of Rhizoma Coptidis were curated from the STP, SEA, and TCMSP databases, alongside disease targets of CAG sourced from PharmGkb, OMIM, and GeneCards databases. By mapping drug targets to disease targets, overlapping targets were identified. A shared protein-protein interaction (PPI) and drug target network were constructed for the overlapping targets and analyzed for KEGG enrichment.

RESULTS

The results of animal experiments demonstrate that TRCE has the potential to improve the CAG process in mice. In conjunction with disease characteristics, cyberpharmacology analysis has identified nine core compounds, 151 targets, 10 core targets, and five significant inflammatory pathways within the compound-target-pathway network. Furthermore, there is a remarkable coincidence rate of 98% between the core compound targets of TRCE and the targets present in the CAG disease database. The accurate search and calculation of literature reports indicate that the coverage rate for 121 predicted core targets related to CAG reaches 81%. The primary characteristic of CAG lies in its inflammatory process. Both predicted and experimental findings confirm that TRCE can regulate ten key inflammation-associated targets (TP53, STAT3, AKT1, HSP90AA1, TNF, IL-6, MAPK3, SRC, JUN, and HSP90AA1) as well as inflammation-related pathways (MAPK, HIF-1, Toll-Like Receptor, IL-17, TNF, and other signaling pathways). These mechanisms mitigate inflammation and reduce gastric mucosal damage in CAG mice.

CONCLUSIONS

In conclusion, TRCE was shown to alleviate CAG by modulating TP53, STAT3, AKT1, HSP90AA1, TNF, IL-6, MAPK3, SRC, JUN, and EGFR, as demonstrated by combined network pharmacology and biological experiments. In conclusion, our study provides a robust foundation for future clinical trials evaluating the efficacy of RC in treating CAG.

Therapeutic potential of diosgenin against methotrexate-induced testicular damage in the rat

This study evaluated diosgenin effects on methotrexate-induced testicular injury in the rats. A single dose of methotrexate (MTX) (20 mg/kg, i.p) was administered, followed by two weeks of diosgenin treatment via gavage starting one day before methotrexate injection. Testicular damage was evaluated through histological examination of seminiferous tubules, as well as analysis of serum testosterone level, oxidative stress and inflammation biomarkers, and antioxidant levels. The results of this study showed that in the MTX-exposed group, oxidative stress indices of malondialdehyde (MDA), reactive oxygen species (ROS), nitrite and indices of inflammation consisting of tumor necrosis factor α (TNFα), and interleukin 6 (IL-6) have a significant increase compared to the control group. Additionally, reductions were observed in antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH). In addition, testosterone level decreased and signs of testicular damage were observed in the MTX group. Conversely, in the group treated with diosgenin alongside MTX at a dosage of 50 mg/kg, there was a significant decrease in oxidative stress markers (MDA, ROS, nitrite) and inflammatory markers (TNFα and IL-6). Moreover, there was a significant increase in the levels of antioxidant enzymes (SOD, CAT, and GSH). Diosgenin appears to have the potential to protect testicular tissue from damage caused by the toxic effects of MTX through the reduction of oxidative stress and inflammation.

Carnitine traffic and human fertility

Carnitine is a vital molecule in human metabolism, prominently involved in fatty acid β-oxidation within mitochondria. Predominantly sourced from dietary intake, carnitine also derives from endogenous synthesis. This review delves into the complex network of carnitine transport and distribution, emphasizing its pivotal role in human fertility. Together with its role in fatty acid oxidation, carnitine modulates the acety-CoA/CoA ratio, influencing carbohydrate metabolism, lipid biosynthesis, and gene expression. The intricate regulation of carnitine homeostasis involves a network of membrane transporters, notably OCTN2, which is central in its absorption, reabsorption, and distribution. OCTN2 dysfunction, results in Primary Carnitine Deficiency (PCD), characterized by systemic carnitine depletion and severe clinical manifestations, including fertility issues. In the male reproductive system, carnitine is crucial for sperm maturation and motility. In the female reproductive system, carnitine supports mitochondrial function necessary for oocyte quality, folliculogenesis, and embryonic development. Indeed, deficiencies in carnitine or its transporters have been linked to asthenozoospermia, reduced sperm quality, and suboptimal fertility outcomes in couples. Moreover, the antioxidant properties of carnitine protect spermatozoa from oxidative stress and help in managing conditions like polycystic ovary syndrome (PCOS) and endometriosis, enhancing sperm viability and fertilization potential of oocytes. This review summarizes the key role of membrane transporters in guaranteeing carnitine homeostasis with a special focus on the implications in fertility and possible treatments of infertility and other related disorders.