Nitric oxide, 8-hydroxydeoxyguanosine, and total antioxidant capacity in human seminal plasma of infertile men and their relationship with sperm parameters

Glyphosate presence in human sperm: First report and positive correlation with oxidative stress in an infertile French population

Environmental exposure to endocrine disruptors, such as pesticides, could contribute to a decline of human fertility. Glyphosate (GLY) is the main component of Glyphosate Based Herbicides (GBHs), which are the most commonly herbicides used in the world. Various animal model studies demonstrated its reprotoxicity. In Europe, GLY authorization in agriculture has been extended until 2034. Meanwhile the toxicity of GLY in humans is still in debate. The aims of our study were firstly to analyse the concentration of GLY and its main metabolite, amino-methyl-phosphonic acid (AMPA) by LC/MS-MS in the seminal and blood plasma in an infertile French men population (n=128). We secondly determined Total Antioxidant Status (TAS) and Total Oxidant Status (TOS) using commercial colorimetric kits and some oxidative stress biomarkers including malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) by ELISA assays. We next analysed potential correlations between GLY and oxidative stress biomarkers concentration and sperm parameters (sperm concentration, progressive speed, anormal forms). Here, we detected for the first time GLY in the human seminal plasma in significant proportions and we showed that its concentration was four times higher than those observed in blood plasma. At the opposite, AMPA was undetectable. We also observed a strong positive correlation between plasma blood GLY concentrations and plasma seminal GLY and 8-OHdG concentrations, the latter reflecting DNA impact. In addition, TOS, Oxidative Stress Index (OSI) (TOS/TAS), MDA blood and seminal plasma concentrations were significantly higher in men with glyphosate in blood and seminal plasma, respectively. Taken together, our results suggest a negative impact of GLY on the human reproductive health and possibly on his progeny. A precaution principle should be applied at the time of the actual discussion of GLY and GBHs formulants uses in Europe by the authorities.

Oxidative Stress Biomarkers in Male Infertility: Established Methodologies and Future Perspectives

Male fertility can be affected by oxidative stress (OS), which occurs when an imbalance between the production of reactive oxygen species (ROS) and the body's ability to neutralize them arises. OS can damage cells and influence sperm production. High levels of lipid peroxidation have been linked to reduced sperm motility and decreased fertilization ability. This literature review discusses the most commonly used biomarkers to measure sperm damage caused by ROS, such as the high level of OS in seminal plasma as an indicator of imbalance in antioxidant activity. The investigated biomarkers include 8-hydroxy-2-deoxyguanosine acid (8-OHdG), a marker of DNA damage caused by ROS, and F2 isoprostanoids (8-isoprostanes) produced by lipid peroxidation. Furthermore, this review focuses on recent methodologies including the NGS polymorphisms and differentially expressed gene (DEG) analysis, as well as the epigenetic mechanisms linked to ROS during spermatogenesis along with new methodologies developed to evaluate OS biomarkers. Finally, this review addresses a valuable insight into the mechanisms of male infertility provided by these advances and how they have led to new treatment possibilities. Overall, the use of biomarkers to evaluate OS in male infertility has supplied innovative diagnostic and therapeutic approaches, enhancing our understanding of male infertility mechanisms.

Omega-3 with and without insulin replacement alleviates detrimental effects of type II diabetes on reproductive system of male C57BL/6 mice

AIMS

this study aimed to examine the protective role of omega-3 and insulin on reproductive system of the male mouse model of type II diabetes mellitus (T2DM), especially DNA integrity and chromatin quality.

MAIN METHODS

adult age-matched mice were divided into intact, sham, or T2DM groups (n = 7) which received a high-fat diet/low-dose streptozotocin. T2DM-induced animals underwent no treatment as diabetic control (T2DM), received omega-3 (T2DM + Omg3), received insulin (T2DM + Ins) and their combination (T2DM + Omg3 + Ins) for 35 days. After which, testicular and sperm parameters and testosterone levels were evaluated.

KEY FINDINGS

our findings revealed that the various examined parameters were comparable between the intact and sham groups, while most testicular and sperm parameters were affected by T2DM. Treatment of T2DM-induced animals with omega-3, alone and in combination with insulin, significantly improved sperm motility, normal morphology, sperm chromatin quality, DNA integrity, Leydig cell number and non-significantly testosterone levels.

SIGNIFICANCE

T2DM interferes with spermatogenesis and steroidogenesis as well as sperm quality and DNA integrity, which can be partially ameliorated by long-term administration of omega-3 in combination with or without insulin. Although our findings should be confirmed in clinical studies, since previous clinical trials have found omega-3 consumption to be beneficial in humans, its use seems to be safe and effective.

The Amino Acid Profile in Seminal Plasma of Normozoospermic Men: A Correlation Analysis with Spermiogram Parameters and Total Antioxidant Capacity

Background

Male infertility is usually determined by the manual evaluation of the semen, namely the standard semen analysis. It is currently impossible to predict sperm fertilizing ability based on the semen analysis alone. Therefore, a more sensitive and selective diagnosis tool is required.

Methods

Twelve fresh semen samples were collected from fertile volunteers attending the Avicenna Fertility Center (Tehran, Iran). The seminal plasma (SP) was prepared and subjected to liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the total antioxidant capacity (TAC) was analysis. Thirty-four amino acids including essential amino acids (EAA), non-essential amino acids (NEAA), and non-proteinogenic amino acids (NPAA) relative concentration were determined, and the correlation between their concentration with spermiogram parameters and TAC of the SP was analyzed.

Results

Significant positive correlations have been found between selected amino acids with the motility (Met and Gln, rs=0.92; Cys, rs=0.72; and Asn, rs=0.82), normal sperm morphology (Met, rs=0.92; Cys, rs=0.72; Glu, rs=0.92; and Asn, rs=0.82), and sperm concentration (Trp, Phe, and Ala). In contrast, several AAs, including Gly, Ser, and Ile showed negative correlations with sperm concentration (rs=-0.93, r=-0.92, and r=-0.89, respectively). Furthermore, TAC showed a positive association only with Tyr (rs=0.79).

Conclusion

The strong positive/negative correlations between the seminal metabolic signature and spermiogram demonstrate the significance of determining metabolite levels under normal conditions for normal sperm functions. Combining the metabolome with the clinical characteristics of semen would enable clinicians to look beyond biomarkers toward the clinical interpretation of seminal parameters to explain the biological basis of sperm pathology.

Sperm cryopreservation for impaired spermatogenesis

Sperm cryopreservation for men with severely impaired spermatogenesis is one of the commonest reasons for short-term sperm storage, usually in advance of fertility treatment. Cryopreservation is generally very effective, although not all spermatozoa survive the process of freezing and thawing. This review considers various aspects of freezing sperm, including an overview of methods, appropriate use of cryoprotectants and practical considerations, as well as oxidative stress and mechanisms of cell cryodamage.

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

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

The Association between Clusterin Sialylation Degree and Levels of Oxidative–Antioxidant Balance Markers in Seminal Plasmas and Blood Sera of Male Partners with Abnormal Sperm Parameters

Nearly 30% of infertility cases are caused by male factor. This study aimed at checking the associations between the sialylation degree of glycoprotein clusterin (CLU) and levels of oxidative–antioxidant balance markers in infertile men. Using lectin-ELISA with biotinylated lectins specific to α2,6-linked (Sambucus nigra agglutinin, SNA) and α2,3-linked (Maackia amurensis agglutinin, MAA) sialic acid (SA), the CLU sialylation in 132 seminal plasmas (SP) and 91 blood sera (BS) were analyzed. Oxidative–antioxidant status was measured by determining Sirtuin-3 (SIRT3), Sirtuin-5 (SIRT5), total antioxidant status (TAS), and ferric reducing antioxidant power (FRAP) levels. We indicate that multiple sperm disorders are associated with decreased expression of MAA-reactive SA in SP. Decreased SP SIRT3 concentrations may be associated with teratozoospermia and oligoasthenoteratozoospermia. ROC curve and cluster analysis revealed that SP relative reactivity of CLU glycans with MAA, the value of MAA/SNA ratio, and SIRT3 and SIRT5 concentrations may constitute an additional set of markers differentiating infertile oligoasthenoteratozoospermic patients (OAT) from normozoospermic (N), asthenoteratozoospermic (AT) and teratozoospermic (T). The multinomial logistic regression analysis confirmed the potential utility of SIRT3 determinations for differentiation between N and OAT groups as well as between N and T groups for SIRT3 and SIRT5. For BS, based on ROC curve and cluster analysis, relative reactivities of CLU glycans with SNA, MAA, SIRT3 and FRAP concentrations may be useful in the differentiation of normozoospermic patients from those with sperm disorders. The multinomial logistic regression analysis showed that the SNA relative reactivity with CLU glycans significantly differentiated the N group from AT, OAT and T groups, and FRAP concentrations significantly differed between N and AT groups, which additionally confirms the potential utility of these biomarkers in the differentiation of infertile patients with abnormal sperm parameters. The knowledge about associations between examined parameters may also influence future research aimed at seeking new male infertility therapies.

Endocrine disruption: Reproductive toxicity of glyceryl trinitrate and isosorbide mononitrate in male Wistar rats

Glyceryl trinitrate (GTN) and isosorbide mononitrate (IM) are organic nitrates which release nitric oxide upon metabolism with potential to adversely affect male reproductive function. Therefore, this study was designed to evaluate the sub-chronic effect of these organic nitrates on reproductive system in male rats. Wistar rats were separately treated with GTN and IM at 2.5, 5 and 7.5 mg/kg/day by oral gavage for 45 days. At the end of treatment, serum blood samples were taken from anaesthetized rats for assessment of hormonal profile. Epididymis was removed to analyse sperm parameters. Rat testes were dissected to perform histopathological evaluation and oxidative stress biomarkers. The GTN and IM treated groups showed a significant decrease in sperm parameters (count, motility and viability) and serum testosterone in comparison to normal control group. The GTN and IM treatment also altered sperm morphology such as bent tail and head deformities as compared to control. A significant decrease in catalase activity and, increase in nitric oxide and malondialdehyde were observed in high dose drug treated groups. Moreover, a significant increase in follicle stimulating hormone and decrease in testosterone levels were evident in all drug treated groups. The level of luteinizing hormone was raised in rats treated with medium doses of drugs while it decreased at the highest dose of both drugs. Histological study showed vacuolization and degeneration of seminiferous tubules. It is concluded that GTN and IM treatment adversely affected the male reproductive function by altering sperm parameters and disrupting the reproductive hormone profile which may be attributed to the increased level of nitric oxide and oxidative stress.

High-Risk HPV with Multiple Infections Promotes CYP2E1, Lipoperoxidation and Pro-Inflammatory Cytokines in Semen of Asymptomatic Infertile Men

High-risk human papillomavirus (HR-HPV) infection, followed by chronic inflammation and oxidative stress, is a major risk factor of male infertility. In this study, we explored the potential impact of high-risk (HR) HPV genotypes in single infection (SI) and multiple infections (MI) that promote CYP2E1 expression, oxidative damage and pro-inflammatory cytokines, possibly contributing to sperm damage and male infertility. Semen samples from 101 infertile military men were studied. We analyzed seminal parameters, namely, HPV genotyping, cytochrome P450 2E1 (CYP2E1), oxidative stress biomarkers (total antioxidant capacity (TAC), catalase (CAT) and superoxide dismutase (SOD)), lipid peroxidation (LPO), 8-hydroxiguanosine (8-OHdG) and pro-inflammatory cytokines (IFN-γ, IL-1β, IL-4, IL-6 and IL-8). Eighty-one men (80.2%, 81/101) were positive for HPV infection, and MI-HR-HPV was higher than SI-HR-HPV (63% vs. 37%). HPV-52 was the most frequently detected type (18.5%), followed by HPV-33 (11.1%), and the most frequent combination of genotypes detected was HPV-33,52 (11.1%), followed by HPV-18,31 (6.2%). The group with infected samples presented lower normal morphology and antioxidant levels compared to non-infected samples. In concordance, the infected group showed high levels of LPO, IFN-γ, IL-1β, IL-4 and IL-6 and downregulation of CAT and SOD enzymes. Interestingly, changes in motility B, low levels of TAC, overexpression of CYP2E1, LPO and IL-8 levels were higher in MI-HR-HPV than SI-HR-HPV, suggesting that HPV infection promotes a chronic inflammatory process and a toxic and oxidative microenvironment, which increases with MI-HPV infections.

Heavy metal and metalloid - induced reproductive toxicity

Heavy metals and metalloid exposure are among the most common factors responsible for reproductive toxicity in human beings. Several studies have indicated that numerous metals and metalloids can display severe adverse properties on the human reproductive system. Metals like lead, silver, cadmium, uranium, vanadium, and mercury and metalloids like arsenic have been known to induce reproductive toxicity. Moderate to minute quantities of lead may affect several reproductive parameters and even affect semen quality. The ecological and industrial exposures to the various heavy metals and metalloids have disastrous effects on the reproductive system ensuing in infertility. This work emphasizes the mechanism and pathophysiology of the aforementioned heavy metals and metalloids in reproductive toxicity. Additionally, this work aims to cover the classical protective mechanisms of zinc, melatonin, chelation therapy, and other trending methods to prevent heavy metal-induced reproductive toxicity.

The Impact of Oxidative Stress in Male Infertility

At present infertility is affecting about 15% of couples and male factor is responsible for almost 50% of infertility cases. Oxidative stress, due to enhanced Reactive Oxygen Species (ROS) production and/or decreased antioxidants, has been repeatedly suggested as a new emerging causative factor of this condition. However, the central roles exerted by ROS in sperm physiology cannot be neglected. On these bases, the present review is focused on illustrating both the role of ROS in male infertility and their main sources of production. Oxidative stress assessment, the clinical use of redox biomarkers and the treatment of oxidative stress-related male infertility are also discussed.

The impact of varying doses of moringa leaf methanolic extract supplementation in the cryopreservation media on sperm quality, oxidants, and antioxidant capacity of frozen-thawed ram sperm

To increase rams' post-thaw semen quality following cryopreservation, this study used enriched Tris-based diluent with varying amounts of moringa leaf methanolic extract (MLME). The antioxidant activity, total phenolic, and total flavonoid content were all assessed in MLME. The sperm of five healthy Awassi rams were collected, divided into 4 equal aliquots, and diluted [1:5; (v/v)] in Tris-citrate-glucose extender supplemented with 0.48, 0.56, and 0.64 mg MLME/ml or without MLME supplementation (control). The percentages of sperm total motility (STM, %), sperm progressive motility (SPM, %) and viability (V, %), abnormal morphology (AM, %), membrane functional integrity (MFI, %), and acrosome integrity (AI %) were measured. Malondialdehyde (MDA), nitric oxide (NO), ascorbic acid (AA), superoxide dismutase (SOD), glutathione peroxidase (GPx), total cholesterol (TC), low-density lipoproteins (LDL), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), zinc (Zn), and copper (Cu) were measured. The total phenolic gallic acid and flavonoid catechin (equivalent) contents were 19.78 mg/g and 11.94 mg/g, respectively. 2,2-Diphenyl-1-picrylhydrazyl (34.37 mM TE/g) and 2,2'-azino-bis/3-ethylbenzothiazoline-6-sulfonic acid (53.47 mM TE/g) were found in MLME. MLME had a 64.59 mM TE/g ferric-reducing power. In comparison to control, the addition of 0.64 mg/ml MLME to Tris-based extender resulted in the highest (P < 0.001) STM (55.22 ± 0.98), SPM (45.41 ± .70), SV (60.01 ± 1.05), MFI (75.23 ± 0.77), and AI (73.13 ± 0.72) and the lowest (P < 0.001) AM (21.34 ± 0.72) values. In comparison to the control, the addition of 0.56 mg/ml semen extender resulted in lower STM, SPM, SV, MFI, and AI with higher AM percentages. MDA (P = 0.03), NO (P = 0.012), CHO (P = 0.0001), and LDL (P = 0.004) were reduced by 0.64 mg/ml MLME, while AA (P = 0.017) and SOD (P = 0.0001) were elevated. In conclusion, the highest copper (P = 0.006) and lowest zinc concentrations in MLME (0.48 mg/ml extender) deteriorated the post-thaw semen quality, prompting us to suggest the addition of 0.64 mg MLME to rams' Tris-based semen extender.

Effects of hazelnut supplemented diet on doxorubicin-induced damage of reproductive system in male rats

The present study was objected to investigate the effect of hazelnut supplemented diet on the levels of oxidative stress and fertility parameters against doxorubicin-induced testicular and epididymal tissue damage of male rats. Rats were randomly divided into four groups (each n = 8), namely control group (CG), doxorubicin group (DG), doxorubicin + hazelnut group (DHG), and doxorubicin + vitamin E group (DEG). This is the first study designed using DHG. Doxorubicin was intraperitoneally injected into all diet groups except CG at a dose of 3 mg/kg body weight on days 1, 7, 14, 21, and 28. In addition, DHG was supplemented with a hazelnut diet at a dose of 3 g/kg body weight/day and vitamin E was added to the drinking water of DEG at a dose of 50 mg/kg body weight/day. DHG reversed the side effects of doxorubicin and positively improved the epididymis sperm quality, testicular and epididymal tissue injury, testosterone level, epididymis oxidative stress index, and lipid peroxidation in male rats. These findings suggest that hazelnut has positive effects against doxorubicin dependent damage on male rats and it may be a promising supplement for amelioration of testicular toxicity. PRACTICAL APPLICATIONS: Hazelnut has numerous positive health effects due to its macronutrients, micronutrients, lipid-soluble compounds and bioactive phenolics. Studies have shown that regular consumption of hazelnut may have a positive effect on lipid parameters, oxidative stress, inflammation markers, and endothelial dysfunction in both healthy people and patients with chronic diseases. Although doxorubicin (Adriamycin, DOX) is an antibiotic that has been widely used in cancer treatment for nearly 30 years, it causes organ toxicity including testicular tissue. Hazelnut may have positive effects on the damage caused by DOX in the reproductive system. However, studies on the effect of hazelnut on male reproductive health are scarce. Therefore, this study provided a basis for the clinical evaluation of the effects of hazelnut on the reproductive system.

Decrease in reproductive dysfunction using aflatoxin B1 exposure: a treatment with 3-indolepropionic acid in albino Wistar rat

We assessed the individual and combined consequence of 3-indolepropionic acid on aflatoxin B1-induced reproductive toxicity in rats. The experimental cohorts were dosed for four consecutive weeks with aflatoxin B1 (50 μg/kg), 3-indolepropionic acid (50 mg/kg), and both (aflatoxin B1: 50 μg/kg + 3-indolepropionic acid: 25 or 50 mg/kg), and the untreated control. Following sacrifice, biomarkers of testicular, epididymal and hypothalamic oxidative status, lipid peroxidation, reactive oxygen and nitrogen species, nitric oxide levels and myeloperoxidase activity were determined. Besides, tumour necrosis factor-alpha, Bcl-2 and Bax proteins were also assessed. Aflatoxin B1-induced testicular, epididymal and hypothalamic oxidative stress was significantly alleviated with 3-indolepropionic acid co-treatment. Also, increases in biomarkers of oxidative stress and reduced levels of antioxidants were abated significantly in rats co-treated with 3-indolepropionic acid. Aflatoxin B1-mediated increase in tumour necrosis factor-alpha, Bax, nitric oxide and myeloperoxidase activity in the examined organs was decreased significantly in aflatoxin B1 and 3-indolepropionic acid co-treated rats. Also, 3-indolepropionic acid dose dependently reduced Bcl-2 levels in the treated rats. The degree of aflatoxin B1-induced histopathological injuries was minimised in rats co-treated with 3-indolepropionic acid. Our results demonstrated that 3-indolepropionic acid protected experimental rats from aflatoxin B1-induced oxido-inflammatory stress and apoptotic response in the examined organs.

Proinflammatory and Oxidative Stress States Induced by Human Papillomavirus and Chlamydia trachomatis Coinfection Affect Sperm Quality in Asymptomatic Infertile Men

Background and Objectives: To investigate the effect of infection with human papillomavirus (HPV) or Chlamydia trachomatis (CT) and HPV + CT coinfection on sperm quality, inflammation, and the state of oxidative stress (OS) in asymptomatic infertile men. Materials and Methods: Semen samples from 84 asymptomatic military infertile men were studied. The polymerase chain reaction (PCR) was used for the molecular detection of HPV and CT. Semen parameters were analyzed according to the World Health Organization guidelines. Inflammation was evaluated by an IL-1β, IL-6, and IFN-γ enzyme-linked immunosorbent assay (ELISA) and OS by the quantification of lipid peroxidation (LPO), 8-hydroxydeoxyguanosine (8-OHdG), and total antioxidant capacity (TAC). Results: A total of 81 of the 84 (96.4%) samples were positives for the pathogens, with 55/81 (68%) being positive for HPV, 11/81 (13.5%) for CT, and 15/81 (18.5%) for HPV + CT coinfection. Seminal parameters were affected in the infected groups, including pH increases above the normal range in all groups. An abnormal sperm morphology was observed in the HPV and HPV + CT groups. Higher cytokine levels were detected in the HPV group and the highest IL-1β level was found in the HPV + CT group. No cytokines were detected in the CT group. High LPO and 8-OHdG levels were found in all groups with a lower TAC. Comparisons between groups showed the highest OS state was observed in the HPV group. Conclusions: High HPV infection or coinfection (HVP + CT) in these infertile men suggest compromising male fertility by inducing a proinflammatory state and OS. Infection with CT suggests an alteration of the state of OS by promoting an alkaline pH.

Current mechanistic perspectives on male reproductive toxicity induced by heavy metals

Environmental and occupational exposures to heavy metals have led to various deleterious damages to the biological system of which infertility is one of them. Infertility is a global public health concern, affecting 15% of all couples of reproductive age. Out of the 100% cases of reported infertility among couples, 40% of the cases are related to male factors; including decreased semen quality. This review focuses on the recent mechanistic perspectives of heavy metal-induced male reproductive toxicity. The associated toxic metal-mediated mechanisms of male reproductive toxicity include ion mimicry, disruption of cell signaling pathways, oxidative stress, altered gene expression, epigenetic regulation of gene expression, apoptosis, disruption of testis/blood barrier, inflammation and endocrine disruption. The current literature suggests that non-coding RNAs (ncRNAs) mediate paternal intergenerational epigenetic inheritance and thus has a direct functional importance, as well as possess novel biomarker potential, for male reproductive toxicity. To identify the specific ncRNAs with the most profound impacts on heavy metal-induced male reproductive toxicity should be thrust of further research.