Detection of oxidative DNA damage in human sperm and its association with sperm function and male infertility

Attenuation of Chronic Oxidative Stress-Induced Testicular and Epididymal Dysfunction by Oral Intake of Lepidium meyenii in New Zealand Rabbits

Lepidium meyenii (Maca) is a plant that has nutritional benefits and increases the effectiveness of male reproduction. In this study, oxidative stress-exposed New Zealand rabbits were used to assess the ameliorative effects of daily Maca ingestion on testicular and epididymal tissues as well as the quality of fresh and frozen/thawed sperm. Twenty-four 40-week-old, healthy New Zealand white male rabbits were divided into four groups. The first group consumed tap water and served as a control. The second group was given 300 mg of Maca daily in capsules. The third group drank water containing hydrogen peroxide (H2O2) at a concentration of 1%. Finally, the fourth group consumed H2O2 and Maca daily. The ejaculate volume, sperm concentration, vitality, motility and velocity of the H2O2 group were considerably lower than those of the other groups. Frozen/thawed spermatozoa showed more dramatic decreases in motility and velocity as a result of H2O2 consumption. The plasma concentrations of testosterone and total antioxidant capacity were also lowest in the H2O2-treated rabbits, while malondialdehyde levels were highest. Exposure to H2O2 increased collagen deposition between ST and epididymal ducts which induced testicular and epididymis fibrosis. In addition, the spermatogenic and epididymal epithelial cells exhibited signs of apoptosis, degeneration, vacuolation and a reduction in height. Maca intake attenuated most of the damaging effects of H2O2 ingestion-induced oxidative stress. Furthermore, H2O2-treated rabbits had modest nuclear androgen receptor positivity, unlike those in the Maca group. The number of Leydig cells significantly increased with daily Maca intake. In conclusion, daily intake of Maca improved reproductive performance and mitigated the damaging effects of oxidative stress on testicular and epididymal functions in New Zealand rabbits.

Clinical Utility of Sperm Function Tests in Predicting Male Fertility: A Systematic Review

Routine semen analysis provides considerable information regarding sperm parameters; however, it is not solely adequate to predict male fertility potential. In the past two decades, several advance sperm function tests have been developed. The present systematic review intends to assess the clinical utility of available advance sperm function tests in predicting the male fertility potential. A systematic literature search was conducted as per PRISMA guidelines using PubMed, MEDLINE, Google Scholar, and Cochrane Library. Different keywords either singly or in combination were used to retrieve the relevant articles related to sperm function tests, male fertility, and pregnancy outcomes. A total of 5169 articles were obtained, out of which 110 meeting the selection criteria were included in this review. The majorly investigated sperm function tests are hypo-osmotic swelling test, acrosome reaction test, sperm capacitation test, hemizona binding assay, sperm DNA fragmentation test, seminal reactive oxygen species test, mitochondrial dysfunction tests, antisperm antibody test, nuclear chromatin de-condensation (NCD) test, etc. The different advance sperm function tests analyse different aspects of sperm function. Hence, any one test may not be helpful to appropriately predict the male fertility potential. Currently, the unavailability of high-quality clinical data, robust thresholds, complex protocols, high cost, etc., are the limiting factors and prohibiting current sperm function tests to reach the clinics. Further multi-centric research efforts are required to fulfil the existing lacunas and pave the way for these tests to be introduced into the clinics.

Differential Sperm Proteomics Reveals the Significance of Fatty Acid Synthase and Clusterin in Idiopathic Recurrent Pregnancy Loss

Recurrent pregnancy loss (RPL) is a pervasive health issue affecting a large number of couples globally, which leads to increased emotional and financial strain on the affected families. While female factors have been extensively studied and are well known, the contribution of male factors to RPL remains largely unknown. As high as 40% of RPL cases are unexplained, which are termed as idiopathic RPL (iRPL), necessitating the investigation of male factors. The role of spermatozoa in early embryonic development is now well established, and recent research studies have shown that oxidative stress and DNA fragmentation in sperm cells are linked to RPL. The aim of this study was to identify proteomic markers of iRPL in human spermatozoa using tandem mass spectrometry. A label-free method quantified a total of 1820 proteins, and statistical analysis identified 359 differentially expressed proteins, the majority of which were downregulated in iRPL samples (344). Bioinformatics analysis revealed that proteomic alterations were mainly associated with biological processes such as response to stress, protein folding, chromatin organization, DNA conformation change, oxidative phosphorylation, and electron transport chain. In coherence with past studies, we determined fatty acid synthase (FASN) and clusterin (CLU) to be the most potential sperm markers for iRPL and confirmed their expression changes in iRPL by western blotting. Conclusively, we believe that FASN and CLU might serve as potential markers of iRPL and suggest exploratory functional studies to identify their specific role in pregnancy loss.

Evaluation of Human Papillomavirus in the Semen of Infertile Men and Its Relationship with Semen Quality

Background: The prevalence of human papillomavirus (HPV) infection in infertile men is significantly higher than that in the general population. Nevertheless, it is unclear whether the presence of HPV in semen samples is related to reduced semen quality. Objectives: The present article aims to elucidate the possible association between HPV infection and semen parameters in Iranian infertile men. Methods: This cross-sectional study included semen samples from 140 infertile Iranian male partners of couples seeking fertility assessment. Standard semen analysis was performed. Sperm DNA fragmentation index (DFI), sperm chromatin maturation, anti-sperm antibodies, leukocyte count, fructose concentration, and zinc concentration were also assessed. Nested polymerase chain reaction (PCR) and INNO-LiPA were used to identify HPV DNA sequences in semen samples and to determine HPV genotype, respectively. Independent samples t-tests were used to compare sperm parameters between HPV-positive and HPV-negative groups. Results: Human papillomavirus DNA was detected in 18 (12.85%) out of 140 semen samples (10% high-risk genotypes, 2.14% low-risk genotypes, and one sample was excluded). Our findings revealed that HPV18 was the most prevalent type (8.57%). According to our results, the presence of HPV DNA in semen samples was associated with higher semen anti-sperm antibodies (P = 0.001), higher white blood cell (WBC) counts (P = 0.02), and increased DFI values (P = 0.03). Conclusions: Human papillomavirus -positive patients had higher semen anti-sperm antibodies, semen WBC counts, and sperm DFI values. These results highlight the importance of careful screening for the presence of HPV in semen samples from infertile men. It should also be noted that more studies are required.

Telomere Length, a New Biomarker of Male (in)Fertility? A Systematic Review of the Literature

Male factors are suspected in around half cases of infertility, of which up to 40% are diagnosed as idiopathic. In the context of a continuously increased resort to ART and increased decline of semen parameters, it is of greatest interest to evaluate an additional potential biomarker of sperm quality. According to PRISMA guidelines, this systematic review of the literature selected studies evaluating telomere length in sperm and/or in leukocytes as a potential male fertility biomarker. Twenty-two publications (3168 participants) were included in this review of experimental evidence. For each study, authors determined if there was a correlation between telomere length and semen parameters or fertility outcomes. Of the 13 studies concerning sperm telomere length (STL) and semen parameters, ten found an association between short STL and altered parameters. Concerning the impact of STL on ART results, the data are conflicting. However, eight of the 13 included studies about fertility found significantly longer sperm telomeres in fertile men than in infertile men. In leukocytes, the seven studies reported conflicting findings. Shorter sperm telomeres appear to be associated with altered semen parameters or male infertility. Telomere length may be considered as a new molecular marker of spermatogenesis and sperm quality, and thus is related to male fertility potential. However, additional studies are needed to define the place of the STL in the assessment of individual fertility.

Mitigation of radiation injury to reproductive system of male mice by Trichostatin A

Trichostatin A (TSA), derived from the bacteria Streptomyces hygroscopicus, is a hydroxamic acid having various biological properties such as histone deacetylase inhibition, anticancer and radiomitigative action. However the mitigative activity of TSA against radiation-induced damages in the mouse reproductive system has not yet been elucidated. The present study unraveled the effects of 2 Gy whole body irradiation (⁶⁰Co γ- radiation) on C57BL/6 mice male reproductive system including structural damages to testes, increase in apoptosis and reduction in germ cell viability, reduced fertility as well as increased genomic instability in the next generation. Moreover, hematological study and micronuclei assay were used to record chances of radiation-induced hematologic cancer and disruption of genomic integrity in F₁ generation. Interestingly, TSA administration 1 and 24 h post-irradiation attenuated radiation-induced morphological damage and cellular apoptosis in testes. In male mice, TSA restored hematological parameters and micronuclei frequency to normal levels, restored sperm viability, and helped them overcome radiation-induced temporary sterility 5 weeks after the irradiation. Thus our results showed that TSA reduced the probability of radiation-induced hematologic cancers as well as genotoxicity and restored genomic integrity in the progenies of paternally exposed mice by reducing radiation-induced apoptosis in spermatogenic cells and restoring cell proliferation. This study suggested that TSA could be used as potential radiomitigator for male reproductive system.

Oxidative stress and DNA damage status in couples undergoing in vitro fertilization treatment

This study examined the status of oxidative stress in 599 couples undertaking in vitro fertilization (IVF) treatment and its association with reproductive hormones, smoking, and outcomes. Oxidative stress biomarkers such as malondialdehyde, 8-hydroxy-2-deoxyguanosine, hydrogen peroxide (H₂O₂), catalase (CAT), and total antioxidant capacity (TAC) were determined in follicular fluid and seminal plasma. Tail moment (TM) was used to evaluate DNA damage in the sperm and granulosa cells. Reproductive hormones in serum and cotinine (COT) in urine, follicular fluid, and seminal plasma samples were determined. Separate multivariate linear regression was used to assess associations between levels of each oxidative stress biomarker and each hormone and smoking parameter (modeled as natural log-transformed). The findings indicate that some oxidative stress and DNA damage biomarkers played a role in disrupting certain reproductive hormones in women and their male partners either by overproducing reactive oxygen species or reducing antioxidant defense capacity. Although women were nonsmokers, COT levels > 50 and 10 µg/L in urine and follicular were observed in 5.7 and 1.7%, respectively. Levels of follicular fluid COT were positively associated with H₂O₂ and TM. We used log-binomial multivariate regression to estimate relative risks for the association between oxidative stress/DNA damage and IVF binary outcomes (fertilization rate > 50%, biochemical pregnancy, clinical pregnancy, and live birth). An increase in the CAT levels of follicular fluid was associated with a 48 and 41% decrease in the risk of poor fertilization rate (≤50%) and unsuccessful live birth, respectively. After the models were adjusted for hormonal factors, the associations remained the same, except that the elevated TAC in follicular fluid became significantly associated with a decrease of 42% in the risk of poor fertilization rate (≤50%). The higher antioxidant activity (CAT and TAC) in follicular fluid might positively impact specific IVF outcomes.

Effect of curcumin on sperm parameters after the cryopreservation

OBJECTIVE

Cryopreservation refers to the cooling of cells and tissues to sub-zero temperatures in order to stop all biologic activity and preserve them for future use. Human sperm cryopreservation is an important tool for assisted reproductive technology and male fertility preservation. However, cryopreservation significantly reduces the quality of spermatozoa. The antioxidant effects of curcumin on different cells have been widely reported. This study was aimed to evaluate changes in post-thaw viability, morphology, motility, chromatin condensation and DNA integrity in response to the addition of curcumin to human sperm freezing extender.

MATERIALS AND METHODS

Semen of 23 normozoospermic men was collected and each sample was divided into three equal aliquots: Control, DMSO, Curcumin. The samples were analyzed freshly for viability (Eosin Y), morphology (Diff-Quick), motility (following WHO standarts), sperm chromatin packaging (aniline blue) and DNA integrity (acridine orange). The control group remained untreated and was mixed with cryopreservation medium (in-house 1:1). The DMSO group was mixed with cryopreservation medium containing 0.1% DMSO. The curcumin group was mixed with cryopreservation medium containing 10 µM curcumin. Samples stained with Diff-Quick and aniline blue were examined under light microscope, samples stained with Eosin Y were examined under phase-contrast microscope and samples stained with acridine orange were examined under fluorescence microscope. Ten days after cryopreservation, samples were thawed and pre-freeze analyses repeated.

RESULTS

Obtained results showed that cryopreservation significantly (P < 0.001) reduces sperm parameters. In Curcumin group, progressive motility, sperm chromatin condensation and DNA integrity significantly (P < 0.001) increased after the thawing process, as compared with the control and the DMSO group.

CONCLUSION

These results suggest that the addition of curcumin to cryopreservation medium improves post-thaw progressive motility, sperm chromatin condensation and DNA integrity. It seems that curcumin ameliorates detrimental effects of cryopreservation on human spermatozoa. Further research is needed on the use of curcumin and other antioxidant substances in sperm cryopreservation.

Nuclear heterogeneity is prevalent in high-quality fractionated human sperm cells typically used for assisted conception

STUDY QUESTION

What is the nuclear heterogeneity of high-density purified human spermatozoa typically used for IVF purposes.

SUMMARY ANSWER

The data show that while density gradient separation has improved the overall sperm population, there is still a large degree of nuclear heterogeneity within these cells.

WHAT IS KNOWN ALREADY

Chromomycin A3 (CMA3) is an important DNA binding fluorochrome for the assessment of male-factor fertility. It is typically used to predict IVF outcomes on entire sperm ejaculates with very high receiver operating characteristic. Here we used CMA3 to characterise typical populations of human spermatozoa that would be used for IVF purposes after density gradient separation.

STUDY DESIGN, SIZE, DURATION

We compared the intensity of CMA3 binding within high-dense sperm populations obtained from men. Binding heterogeneity was confirmed through fluorescence microscopy and FACS analysis independently. We also looked at CMA3 staining directly with head morphology in this sperm population. Finally, we looked at electron micrographs of nuclear heterogeneity (vacuoles, chromatin compaction) of spermatozoa following density gradient sorting of CMA3-stained cells.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We used sperm donors who had fathered one or more children. Semen was collected after 2 days abstinence and purified over Percoll gradients. Only the high-quality spermatozoa, the same used for assisted conception, were then used. Cells were stained with CMA3 and sorted using FACS. Following this, electron micrographs were used to assess nuclear heterogeneity of CMA3-dependent sorted spermatozoa.

MAIN RESULTS AND THE ROLE OF CHANCE

CMA3 staining occurs within morphologically normal as well as abnormal spermatozoa. High-intensity CMA3-stained sperm possessed large vacuoles that were not seen in the low-CMA3 population. In addition, the high-CMA3 stained cells possess higher amounts of nuclear granulation.

LIMITATIONS, REASONS FOR CAUTION

The present study only describes the issues within the chromatin of these cells and does not suggest an alternate selection technique.

WIDER IMPLICATIONS OF THE FINDINGS

CMA3 is one of the better reported prognostic assays in predicting pregnancy outcomes, especially in cases where the male is at fault. However, it is clear that even in fractionated populations of human spermatozoa, there are sperm cells that are morphologically normal yet possess high levels of CMA3 staining and chromatin granulation. The implication of this is that the embryologist, whom selects on the basis of sperm morphology, may choose a cell with poor chromatin, which may lead to poor embryo outcomes.

STUDY FUNDING/COMPETING INTEREST(S)

The project was funded by the National Health and Medical Research council, APP1118943. The authors have no conflict of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Prospective analysis over time of semen parameters in spinal cord-injured patients: Results of a pilot study

BACKGROUND

Spinal cord injury often results in erectile dysfunction and an ejaculation along with impaired semen parameters. Fertility is a major concern in spinal cord injury adult males and some fear that the delay post-spinal cord injury may negatively affect sperm quality.

OBJECTIVES

We aimed to (i) assess semen parameters over time in SCI patients according to age at spinal cord injury, time post-spinal cord injury, and the spinal cord injury level and completeness and (ii) measure markers in semen for inflammation and marker of oxidative stress to investigate their impact on sperm parameters.

MATERIALS AND METHODS

The study is a prospective, longitudinal, pilot study over 18 months. Thirty-five men with spinal cord injury from 18 to 60 years of age were enrolled. Their mean age was 29.4 ± 6.4 years. Semen retrieval was scheduled every 6 months, allowing analysis of four ejaculates, in association with measurement of granulocyte and seminal plasma elastase concentrations to assess markers in semen for inflammation and spermatozoa DNA fragmentation to assess oxidative stress.

RESULTS

Based on reference limits, a normal total sperm number, decreased motility and vitality of the spermatozoa, and increased morphological abnormalities were found. Mean round cell and granulocyte concentrations were elevated in the semen. Markers in semen for inflammation and marker of oxidative stress were elevated in several semen samples, compared to reference limits. However, neither the presence of markers in semen for inflammation or oxidative stress, the completeness or the level of the spinal cord lesion, the age or the time post-spinal cord injury had a negative impact on the semen quality over time.

DISCUSSION

There was no significant decline in semen quality in spinal cord injury patients over time within the limitations of this pilot study. Moreover, a chronic genital inflammatory status was not associated with impairment of semen quality.

CONCLUSION

The present findings are reassuring for men with spinal cord injury and could guide the management of their reproductive ability. According to these preliminary data, not all spinal cord injury patients who are able to ejaculate require systematic freezing of their spermatozoa.

A Comparative Study of the Effects of Valproate and Oxcarbazepine on Sexual Function, Sperm Quality, and Sex Hormones in Males with Epilepsy

Aims

Although several studies have indicated that valproate (VPA) and oxcarbazepine (OXC) cause reproductive endocrine disorders and sexual dysfunction, there remains some controversy regarding these issues in males with epilepsy. This study is aimed at evaluating the effects of VPA and OXC on sexual function, sperm quality, and sex hormones in young males with epilepsy.

Methods

Males with newly diagnosed epilepsy treated with VPA and OXC were recruited, and sexual function questionnaires (International Index of Erectile Function-5 (IIEF-5)), sperm quality, and sex hormone levels were assessed before treatment and at 6 months after treatment with VPA or OXC monotherapy.

Results

Forty-four young males with epilepsy (23 treated with VPA, 21 treated with OXC) and 30 age-matched healthy individuals were recruited for our study. The sexual function, sperm quality, marriage rate, and fertility rate of these young males with epilepsy were lower than those of healthy controls. Sperm quality were significantly reduced in young male patients after 6 months of VPA administration. The level of follicle stimulating hormone (FSH) was increased in patients after OXC treatment. Meanwhile, sexual function and sperm quality were not affected.

Conclusion

Sexual function and sperm quality were reduced in young males with epilepsy. VPA may exert a negative effect on sperm quality, whereas OXC has no harmful effect on sexual function and sperm quality in young males with epilepsy.

Use of testicular sperm in couples with SCSA-defined high sperm DNA fragmentation and failed intracytoplasmic sperm injection using ejaculated sperm

Sperm DNA fragmentation (SDF) has been linked with male infertility, and previous studies suggest that SDF can have negative influence on pregnancy outcomes with assisted reproduction. We performed a retrospective review of consecutive couples with a high SDF level that had intracytoplasmic sperm injection (ICSI) using testicular sperm (T-ICSI). We compared the T-ICSI outcomes to that of two control groups: 87 couples with failed first ICSI cycle and who had a second ICSI cycle using ejaculated sperm (Ej-ICSI), and 48 consecutive couples with high sperm chromatin structure assay (SCSA)-defined SDF (>15%) that underwent an ICSI cycle using ejaculated sperm after one or more failed ICSI cycles (Ej-ICSI-high SDF). The mean number of oocytes that were retrieved and the total number of embryos were not different among the three groups. The mean number of transferred embryos in the T-ICSI group was higher than the Ej-ICSI group but not significantly different than the Ej-ICSI-high SDF group (1.4, 1.2, and 1.3, respectively, P < 0.05). Clinical pregnancy rate in the T-ICSI group was not significantly different than the Ej-ICSI and Ej-ICSI-high SDF groups (48.6%, 48.2%, and 38.7%, respectively, P > 0.05). No significant difference was found in live birth rate when comparing T-ICSI to Ej-ICSI and Ej-ICSI-high SDF groups. The results suggest that pregnancy outcomes and live birth rates with T-ICSI are not significantly superior to Ej-ICSI in patients with an elevated SCSA-defined sperm DNA fragmentation and prior ICSI failure(s).

Oxidative stress and male infertility

BACKGROUND

Between 30% and 80% of patients with male infertility produce excessive reactive oxygen species (ROS) in their ejaculate even though the cause of male infertility is unexplained in approximately half of cases. The strong connection between oxidative stress (OS) and male infertility has led recent investigators to propose the term "Male Oxidative Stress Infertility (MOSI)" to describe OS-associated male infertility.

METHODS

We searched the PubMed database for original and review articles to survey the effects of OS on male infertility, and then verified the effects and treatments.

MAIN FINDINGS

Seminal plasma contains many antioxidants that protect sperm from ROS, because low amounts of ROS are required in the physiological fertilization process. The production of excessive ROS causes OS which can lower fertility through lipid peroxidation, sperm DNA damage, and apoptosis. Several assays are available for evaluating OS, including the MiOXSYS® analyzer to measure oxidation-reduction potential. Several measures should be considered for minimizing OS and improving clinical outcomes.

CONCLUSION

Accurately diagnosing patients with MOSI and identifying highly sensitive biomarkers through proteomics technology is vital for better clinical outcomes.

The Sins of Our Forefathers: Paternal Impacts on De Novo Mutation Rate and Development

Spermatogonial stem cells (SSCs) are generally characterized by excellent DNA surveillance and repair, resulting in one of the lowest spontaneous mutation rates in the body. However, the barriers to mutagenesis can be overwhelmed under two sets of circumstances. First, replication errors may generate age-dependent mutations that provide the mutant cells with a selective advantage, leading to the clonal expansions responsible for dominant genetic diseases such as Apert syndrome and achondroplasia. The second mechanism centers on the vulnerability of the male germline to oxidative stress and the induction of oxidative DNA damage in spermatozoa. Defective repair of such oxidative damage in the fertilized oocyte results in the creation of mutations in the zygote that can influence the health and well-being of the offspring. A particular hot spot for such oxidative attack on chromosome 15 has been found to align with several mutations responsible for paternally mediated disease, including cancer, psychiatric disorders, and infertility.

Radioprotective Agents and Enhancers Factors. Preventive and Therapeutic Strategies for Oxidative Induced Radiotherapy Damages in Hematological Malignancies

Radiation therapy plays a critical role in the management of a wide range of hematologic malignancies. It is well known that the post-irradiation damages both in the bone marrow and in other organs are the main causes of post-irradiation morbidity and mortality. Tumor control without producing extensive damage to the surrounding normal cells, through the use of radioprotectors, is of special clinical relevance in radiotherapy. An increasing amount of data is helping to clarify the role of oxidative stress in toxicity and therapy response. Radioprotective agents are substances that moderate the oxidative effects of radiation on healthy normal tissues while preserving the sensitivity to radiation damage in tumor cells. As well as the substances capable of carrying out a protective action against the oxidative damage caused by radiotherapy, other substances have been identified as possible enhancers of the radiotherapy and cytotoxic activity via an oxidative effect. The purpose of this review was to examine the data in the literature on the possible use of old and new substances to increase the efficacy of radiation treatment in hematological diseases and to reduce the harmful effects of the treatment.

Comparative analysis of tests used to assess sperm chromatin integrity and DNA fragmentation

Male infertility has a complex etiology, and many times, the cause is unknown. While routine semen analysis provides an overview of basic semen parameters, such as sperm concentration, motility, viability and morphology, a significant overlap of these parameters has been reported in fertile and infertile men. Moreover, conventional semen parameters do not reveal the cellular or molecular mechanisms of sperm dysfunctions leading to infertility. Therefore, sperm functional parameters, including sperm chromatin integrity, are evaluated to provide information on subtle sperm defects that are not routinely identified. Incomplete or defective sperm chromatin condensation increases the susceptibility of the sperm DNA to oxidative damage or other factors. To evaluate sperm chromatin integrity, different methods with varying degrees of diagnostic and prognostic capabilities are available. Among these assays, SCSA, TUNEL and SCD assays are most commonly used. While these assays rather evaluate the DNA directly for damages, the aniline blue and chromomycin A3 stains test for the quality of chromatin condensation. Thus, this review discusses and compares different methods used to evaluate sperm chromatin integrity and condensation, and their inclusion in the routine evaluation of the male infertility.

Sperm DNA Integrity and Male Fertility in Farm Animals: A Review

The accurate prediction of male fertility is of major economic importance in the animal breeding industry. However, the results of conventional semen analysis do not always correlate with field fertility outcomes. There is evidence to indicate that mammalian fertilization and subsequent embryo development depend, in part, on the inherent integrity of the sperm DNA. Understanding the complex packaging of mammalian sperm chromatin and assessment of DNA integrity could potentially provide a benchmark in clinical infertility. In the era of assisted reproduction, especially when in-vitro fertilization or gamete intrafallopian transfer or intracytoplasmic sperm injection is used, assessment of sperm DNA integrity is important because spermatozoa are not subjected to the selection process occurring naturally in the female reproductive tract. Although sperm DNA integrity testing measures a significant biological parameter, its precise role in the infertility evaluation in farm animals remains unclear. In this review, the earlier findings on sperm DNA integrity in relation to male fertility are compiled and analyzed. Furthermore, the causes and consequences of sperm DNA damage are described, together with a review of advances in methods for detection of sperm DNA damage, and the prognostic value of sperm DNA quality on male fertility.

Respiratory Mitochondrial Efficiency and DNA Oxidation in Human Sperm after In Vitro Myo-Inositol Treatment

Semen samples are known to contain abnormal amounts of reactive oxygen species (ROS) and oxygen free radicals; therefore, the identification of antioxidant molecules able to counteract the oxidative damage caused by ROS is foresight. Indeed, improving semen quality in terms of motility and reduction in DNA damage, can significantly improve the fertilization potential of sperm in vitro. To this regard, myo-inositol, based on its antioxidant properties, has been reported to be effective in improving sperm quality and motility in oligoasthenozoospermic patients undergoing assisted reproduction techniques when used as a dietary supplementation. Moreover, in vitro treatment demonstrated a direct relationship between myo-inositol, mitochondrial membrane potential and sperm motility. This experimental study aimed to evaluate the effects of myo-inositol (Andrositol-lab) in vitro treatment on sperm motility, capacitation, mitochondrial oxidative phosphorylation and DNA damage. Our results demonstrate that myo-inositol induces a significant increase in sperm motility and in oxygen consumption, the main index of oxidative phosphorylation efficiency and ATP production, both in basal and in in vitro capacitated samples. Moreover, we provide evidence for a significant protective role of myo-inositol against oxidative damage to DNA, thus supporting the in vitro use of myo-inositol in assisted reproductive techniques. Even if further studies are needed to clarify the mechanisms underlying the antioxidant properties of myo-inositol, the present findings significantly extend our knowledge on human male fertility and pave the way to the definition of evidence-based guidelines, aiming to improve the in vitro procedure currently used in ART laboratory for sperm selection.

Association of single-nucleotide polymorphisms in antioxidant genes and their gene-gene interactions with risk of male infertility in a Chinese population

The antioxidant defense system protects DNA from the damaging effects of oxidative stress and is hypothesized to be associated with an increased risk of male infertility. Polymorphisms in antioxidant genes and the gene-gene interactions associated with the antioxidant system may increase the potential risk of male infertility. In the present case-controlled study, the individual link between seven gene polymorphisms (NQO1 rs1800566, SOD2 rs4880, GSTM3 rs1571858, rs3814309, rs7483, GSTM5 rs11807 and GSTP1 rs1695) and the risk of male infertility was investigated. A total of 248 idiopathic infertility patients and 310 fertile controls were selected, and genotyping was performed using the Mass ARRAY platform. There were no significant associations between the seven polymorphisms and risk of male infertility. However, the analysis of gene-gene interactions showed a decreased risk of male infertility in GSTM3 rs3814309/NQO1 rs1800566 [CC x CT/TT; odds ratio (OR)=0.56, 95% confidence interval (CI)=0.34-0.92; P=0.022), and a significant association between a gene-gene interaction in GSTM3 rs1571858/NQO1 rs1800566 and azoospermia (AG/GG x CC; OR=3.84, 95% CI=1.25-11.81; P=0.019).

Zeta potential technique for analyzing semen quality

The presented study shows the possibility of using the zeta potential technique in sperm selection. Results suggest that the characteristics of semen may be reflected in the sperm surface charge, which can be measured by a simple Zeta technique. This is a pilot study that answers question whether a commercially available Zeta Potential analyzer can be used to determine the quality of human semen. Semen samples were obtained from young adult men donors and divided into portions to analyze the motility, viability, morphology, concentration and zeta potential. Results indicate that zeta potential of semen samples with right structural and functional parameters was significantly more negative in comparison to the other samples. Our use of a Zeta potential analyzer to investigate sperm surface charge adds a new dimension to data on semen quality. It is an additional simple method that helps in the widely-used routine methods of semen analysis. •

Characteristics of semen may be reflected in the sperm surface charge, which can be measured by Zeta potential technique.

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Only 20 µl semen being needed to analyze spermatozoa surface charge.

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The commercially available Zeta Potential analyzer can be applied for semen quality investigation.

The Relationship Between Widespread Pollution Exposure and Oxidized Products of Nucleic Acids in Seminal Plasma and Urine in Males Attending a Fertility Center

Background: In recent decades, there has been an increase in male infertility, and in many cases, the etiology remains unclear. Several studies relate male hypo-fertility to xenobiotic exposure, even if no data exist about multiple exposure at the environmental level. Methods: The study involved 86 males with diagnosis of idiopathic male infertility (IMI), and 46 controls with no alteration in sperm characteristics. Seminal plasma (SP) and urine samples were analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS) to quantify biomarkers of exposure (the main metabolites of benzene, toluene, 1,3-butadiene, 3-monochloropropanediol, styrene, and naphthol) and effect (oxidized products of nucleic acids).Results: Biomarker concentrations were similar in subjects with IMI and controls even if a stronger correlation between biomarkers of exposure and effects were observed in SP. Data show that, both in SP and urine, most metabolites were inter-correlated, indicating a simultaneous co-exposure to the selected substances at the environmental level. Principal component analysis showed in SP the clustering of mercapturic acids indicating a preferential metabolic pathway with Glutathione (GSH) depletion and, consequently, an increase of oxidative stress. This result was also confirmed by multivariable analysis through the development of explanatory models for oxidized products of nucleic acids. Conclusions: This study highlights how oxidative stress on the male reproductive tract can be associated with a different representation of metabolic pathways making the reproductive tract itself a target organ for different environmental pollutants. Our results demonstrate that SP is a suitable matrix to assess the exposure and evaluate the effects of reproductive toxicants in environmental/occupational medicine. The statistical approach proposed in this work represents a model appropriate to study the relationship between multiple exposure and effect, applicable even to a wider variety of chemicals.

Protective effect of rutin on mercuric chloride-induced reproductive damage in male rats

This study investigated the effects of rutin against reproductive damage caused by toxic mercury in male rats. Thirty-five Sprague Dawley rats were used. Control group was injected with saline for 7 days. The rutin-100 group received 100 mg/kg/b.w. rutin for 7 days. Mercuric chloride (HgCl₂ ) group received 1.23 mg/kg/b.w. of HgCl₂ for 7 days. Mercury chloride + rutin-50 group received 50 mg/kg/b.w. rutin and HgCl₂ 1.23 mg/kg/b.w. for 7 days. HgCl₂  + rutin-100 group received 100 mg/kg/b.w. rutin and HgCl₂ 1.23 mg/kg/b.w. for 7 days. It was detected that HgCl₂ treatment increased malondialdehyde (MDA) levels, tumour necrosis factor-α (TNF-α) and cyclooxygenase-2 (COX-2) expressions, necrosis and degeneration of spermatogonium, dead and abnormal sperm percentages; tubular walls thinning; and decreased antioxidant enzyme activities and sperm motility. It was determined that rutin application reduced testicular damage caused by HgCl₂ . In conclusion, rutin administration may treat HgCl₂ toxicity in testes.

The role of propolis against paclitaxel-induced oligospermia, sperm abnormality, oxidative stress and DNA damage in testes of male rats

Paclitaxel (taxol) is one of the most powerful anticancer drugs but it possesses toxic effects on male reproductive system. Propolis, from folkloric remedy, have antioxidant, anti-inflammatory and anticancer effects. The present study established to examine the protective impact of Propolis against malformation of semen induced by taxol. Twenty-four male rats equally divided into four groups. Group I (normal control); group II, administrated Propolis alone; group III, taxol-treated group received taxol; group IV, co-administered of taxol and Propolis extract. After 4 weeks of treatment, the semen were collected and testis 24 hr after the last treatment. Sperm count, motility, viability and sperm morphology were assayed. Tissue supernatants were isolated for oxidative stress, cell energy parameters and 8-OHdG. DNA damage was evaluated using Comet assay in testes. Our results confirmed that taxol-induced significant reduction in sperm count, motility, viability and recorded marked elevation in sperm abnormalities. Also, taxol caused increased in 8-OHdG and DNA damage versus that recorded in control group. Treatment with Propolis improving semen quality and protected testis from detrimental effects of taxol and minimises its toxicity. In conclusions, Oral administration of Propolis modulates the toxic impact of taxol by amelioration semen quality, diminishing oxidation state, DNA damage and preserving cell energy.

Nano-selenium attenuates nickel-induced testosterone synthesis disturbance through inhibition of MAPK pathways in Sprague-Dawley rats

The aim of this study was to investigate the protective effects of Nano-Se against Ni-induced testosterone synthesis disorder in rats and determine the underlying protective mechanism. Sprague-Dawley rats were co-treated with Ni (5.0 mg/kg, i.p.) and Nano-Se (0.5, 1.0, and 2.0 mg/kg, oral gavage) for 14 days after which various endpoints were evaluated. The Ni-induced abnormal pathological changes and elevated 8-OHdG levels in the testes were attenuated by Nano-Se administration. Importantly, decreased serum testosterone levels in the Ni-treated rats were significantly restored by Nano-Se treatment, particularly at 1.0 and 2.0 mg/kg. Furthermore, the mRNA and protein levels of testosterone synthetase were increased by Nano-Se compared to the Ni group, whereas phosphorylated protein expression levels of mitogen-activated protein kinase (MAPK) pathways were suppressed by Nano-Se administration in the Ni-treated rats. Overall, the results suggest that Nano-Se may ameliorate the Ni-induced testosterone synthesis disturbance via the inhibition of ERK1/2, p38, and JNK MAPK pathways.

Sperm quality and hormonal levels in C57BL/6 mice infected with Neospora caninum

Neospora caninum is a major pathogen of cattle and dogs, and neosporosis is widespread in five continents. In this study effect of experimental neosporosis on sperm quality of C57BL/6 mice in different days was investigated. Based on the results sperm concentration was not changed in infected groups but neosporosis induced a significant decrease in epididymis sperm motility at 60 days post infection. A significant increase in the number of abnormal sperms at five, 15, 30 and 60 days post infection was found. At days 15, 30 and 60 post infection testosterone concentrations were significantly low in infected groups and FSH level was significantly high in infected groups at five and 30 days post infection. LH level was decreased in infected groups, but the difference was significant at five, 15 and 30 days post infection. Comparison of TSH and T4 levels between groups revealed a significant decrease in infected groups at five, 15, 30 and 60 days post infection. Except 15 days post infection T3 levels decreased significantly in infected groups. GPX activity, MDA and TAC level was significantly increased in infected mice at five days post infection. In this study neosporosis is associated with hypogonadotrophic gonadal insufficiency in infected C57BL/6 male mice.

Deterioration of semen quality and sperm-DNA integrity as influenced by cigarette smoking in fertile and infertile human male smokers-A prospective study

In modernized lifestyle smoking is one of the trendy, psychological, and socioeconomic scenarios of young adolescents mainly in the age of the reproductive stage. Based on a number of cigarettes smoked, age, and duration of the smoke, the study aims to search for the profound effects of smoking and its impact on semen parameters, sperm-DNA integrity, and fragmentation of sperm DNA with cotinine and apoptotic caspase-3 marker in the seminal plasma of fertile and infertile smokers. To determine oxidative damage by 8-hydroxy deoxyguanosine (8-OHdG) from isolated sperm DNA (steps: reactive oxygen species washing by nitro blue tetrazolium (NBT), sperm lysis, salt digestion, ethanol washing, and finally with high-performance liquid chromatography analysis). Level of DNA fragmentation (percentage) in native and intact DNA, the activity of caspase-3 in infertile smokers will be compared with the control group of nonsmokers. Also, the sperm viability was visualized by eosin-nigrosin and aniline blue staining. Cotinine is one of the best markers of smoking. The cotinine level (2224.24 ± 1.19 *** ng/mL), when abundant it negative correlates with morphology and rapid motility in infertile smokers than nonsmokers. Gel preprogram measured the sperm integrity and was found to be less in smokers than nonsmokers. The spermatic oxidative marker 8-OHdG was high and gave an R ² value of 0.9104 with morphology and 0.9007 for rapid motility of infertile sperm, respectively. Infertile smoking subjects (<10 cigarettes/day) had significant changes increase in sperm fragmentation, caspase-3, and cotinine while negative impact with motility, morphology, and pH of semen compared with fertile, infertile nonsmoking subjects.

Oxidative stress and sperm function: A systematic review on evaluation and management

Objective: To review and present the most distinct concepts on the association of reactive oxygen species (ROS) with male reproduction.

Methods: The Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) guidelines were used to search PubMed, Medline, EMBASE, and the Cochrane electronic databases for studies investigating the role of oxidative stress (OS) on sperm function.

Results: The literature search yielded 1857 studies, of which 1791 articles were excluded because of irrelevance of data, non-English language, non-human nature or because they were case reports or commentaries. All included studies were reviews (46), meta-analyses (one), original research studies (18) and guideline articles (one). The studies were published between 1984 and 2018. Under normal physiological conditions, ROS are vital for sperm maturation, hyperactivation, capacitation, acrosome reaction, as well as fertilisation. However, a number of endogenous and exogenous causes may induce supra-physiological levels of ROS resulting in lipid peroxidation, sperm DNA fragmentation and apoptosis, and consequently infertility. Several laboratory testing methods can be used in infertile men to diagnose OS. Treatment usually involves antioxidant supplementation and, when possible, elimination of the causative factor.

Conclusion: OS is an important cause of male factor infertility. Its assessment provides essential information that can guide treatment strategies aimed at improving the male’s reproductive potential.

Abbreviations: bp: base-pair; CAT: catalase; LPO: lipid peroxidation; MDA: malondialdehyde; MiOXSYS: Male Infertility Oxidative System; mtDNA: mitochondrial DNA; NAD(PH): nicotinamide adenine dinucleotide (phosphate); NO: nitric oxide; 8-OHdG: 8-hydroxy-2’-deoxyguanosine; ORP: oxidation–reduction potential; OS: oxidative stress; PKA: protein kinase A; PLA2: phospholipase A2; PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-Analyses; PUFA: poly-unsaturated fatty acid; ROS: reactive oxygen species; SOD: superoxide dismutase; TAC: total antioxidant capacity; TBA: thiobarbituric acid

Royal jelly protects male rats from heat stress-induced reproductive failure

Royal jelly (RJ) as an antioxidant has been shown to have attenuated oxidative stress damages in reproductive organs. The objective was carried out the effects of RJ on sperm characteristics, sperm malondialdehyde (MDA) concentration and in vitro fertilisation (IVF) outcome in heat stress (HS) exposed male rats. Forty-eight male rats were randomly divided into eight groups; group 1 received normal saline, group 2 received RJ (100 mg kg^-1  day^-1 ; PO), groups 3, 4 and 5 were heat-stressed (43, 39 and 37°C for 20 min per day respectively) and groups 6, 7 and 8 were heat-stressed along with RJ (43, 39 and 37°C for 20 min per day, respectively, plus RJ at a dose of 100 mg kg^-1  day^-1 ; PO). The HS was induced through immersion of experimental rat scrotums in a water bath. After 48 days, the HS induced remarkable diminish in sperm motility, viability and fertilising potential along with reduced blastulation rate and enhanced sperm chromatin abnormality, MDA levels and DNA damage. Nevertheless, RJ co-administration improved sperm characteristics and early embryo development as well as sperm lipid peroxidation level. Our data suggest that RJ can effectively ameliorate the experimental HS-induced infertility in rats through MDA concentration restoration and sperm characteristics and pre-implantation embryo development improvement.

Trichostatin A, an epigenetic modifier, mitigates radiation-induced androphysiological anomalies and metabolite changes in mice as evident from NMR-based metabolomics

PURPOSE

Ionizing radiation is known to damage male reproductive system. Current study aims to study the mitigative effects of trichostatin A on male reproductive system and accompanying metabolite changes in testicular tissue of mice.

MATERIALS AND METHODS

Eight-week-old male C57 Bl/6J mice were exposed to 2 Gy γ-radiation with or without trichostatin A administration. The animals were sacrificed at various time intervals for organ body weight index, sperm head abnormality assay, sperm mobility assay, and study of various metabolites in testicular tissue using NMR spectroscopy.

RESULTS

Ionizing radiation induced no significant change in organ body weight index at any time points studied, however a significant increase in sperm head abnormality and significant decrease in sperm mobility was evident on fifth postirradiation week. trichostatin A administration, 1 and 24 h postirradiation, could efficiently mitigate radiation-induced changes studied. NMR metabolome profile also showed prominent changes associated with energy metabolism, osmolytes and membrane metabolism at 24 h postirradiation and some of these changes (choline, glycerolphosphoethanol amine, and glycine) were persistent till fifth postirradiation week. Trichostatin A administration resulted in reverting metabolic profile of the irradiated animals to normal level suggesting its mitigative role.

CONCLUSION

Results obtained suggest that trichostatin A could restore normal metabolic profile of testicular tissue of irradiated male mice and also restored certain morphological and functional properties of sperms. Trichostatin A thus could further be exploited for its radio-mitigative properties.

Royal jelly protects male mice against nicotine-induced reproductive failure

This study evaluated the possible protective effect of royal jelly (RJ) on sperm parameters and sperm malondialdehyde (MDA) concentration and in vitro fertilizing potential in nicotine (NIC) exposed male mice. Thrtiy-six male BALB/c mice were randomly divided into six groups (n = 6). Group 1 received normal saline, group 2 received 100 mg kg-1 per day RJ, groups 3 and 4 received NIC at doses of 0.50 and 1.00 mg kg-1 per day, respectively and groups 5 and 6 received NIC at doses of 0.50 and 1.00 mg kg-1 per day, respectively plus RJ. Caudal epididymal sperm characteristics, lipid peroxidation and in vitro fertilizing capacity and embryo development were evaluated after 35 days. The NIC treatment caused a significant decrease in sperm motility and viability and fertilization rate along with poor blastocyst formation and increased sperm DNA damage and MDA levels. Moreover, the incidences of chromatin abnormality in spermatozoa were significantly higher in NIC-exposed mice than those of control. Nevertheless, RJ treatment improved sperm parameters and in vitro fertilization outcome as well as sperm lipid peroxidation level. Data from the current study suggest that RJ has a potential repro-protective action against NIC-induced sperm abnormalities and embryotoxicity in mice.

Sub-fertile sperm cells exemplify telomere dysfunction

PURPOSE

The purpose of this study was to evaluate telomere homeostasis in sub-fertile compared to fertile human sperm.

METHODS

This observational, comparative study included 16 sub-fertile men who required intracytoplasmic sperm injection and 10 fertile men. At least 100 sperm cells from each participant were assessed. Main outcome measures were telomere length and telomere aggregates. Telomerase RNA component (TERC) copy number and telomere capture were assessed using fluorescence in situ hybridization technique and human telomerase reverse transcriptase (hTERT) using immunohistochemistry.

RESULTS

Clinical backgrounds were similar. The percentage of sperm cells with shorter telomeres was higher among the sub-fertile compared to the fertile participants (3.3 ± 3.1 vs. 0.6 ± 1.2%, respectively; P < 0.005). The percentage of cells with telomere aggregates was significantly higher in the sub-fertile group (15.12 ± 3.73 vs. 4.73 ± 3.73%; P < 0.005). TERC gene copy number was similar between groups. The percentage of cells that were positive for hTERT was lower in the sub-fertile group (3.81 ± 1.27 vs. 8.42 ± 1.80%; P < 0.005). Telomere capture rates were higher among the sub-fertile sperm cells (P < 0.005).

CONCLUSIONS

Sub-fertile sperm cells have short telomeres that are elongated by the alternative pathway of telomere capture. Dysfunctional telomeres may affect sperm fertilizability.

Oxidative stress and respiratory symptoms due to human exposure to polycyclic aromatic hydrocarbons (PAHs) in Kumasi, Ghana

Studies of polycyclic aromatic hydrocarbons (PAHs) and its metabolites in PM10, soils, rat livers and cattle urine in Kumasi, Ghana, revealed high concentrations and cancer potency. In addition, WHO and IARC have reported an increase in cancer incidence and respiratory diseases in Ghana. Human urine were therefore collected from urban and control sites to: assess the health effects associated with PAHs exposure using malondialdehyde (MDA) and 8-hydroxy-2-deoxyguanosine (8-OHdG); identify any association between OH-PAHs, MDA, 8-OHdG with age and sex; and determine the relationship between PAHs exposure and occurrence of respiratory diseases. From the results, urinary concentrations of the sum of OH-PAHs (∑OHPAHs) were significantly higher from urban sites compared to the control site. Geometric mean concentrations adjusted by specific gravity, GM_SG, indicated 2-OHNaphthalene (2-OHNap) (6.01 ± 4.21 ng/mL) as the most abundant OH-PAH, and exposure could be through the use of naphthalene-containing-mothballs in drinking water purification, insect repellent, freshener in clothes and/or "treatment of various ailments". The study revealed that exposure to naphthalene significantly increases the occurrence of persistent cough (OR = 2.68, CI: 1.43-5.05), persistent headache (OR = 1.82, CI: 1.02-3.26), tachycardia (OR = 3.36, CI: 1.39-8.10) and dyspnea (OR = 3.07, CI: 1.27-7.43) in Kumasi residents. Highest level of urinary 2-OHNap (224 ng/mL) was detected in a female, who reported symptoms of persistent cough, headache, tachycardia, nasal congestion and inflammation, all of which are symptoms of naphthalene exposure according to USEPA. The ∑OHPAHs, 2-OHNap, 2-3-OHFluorenes, and -OHPhenanthrenes showed a significantly positive correlation with MDA and 4-OHPhenanthrene with 8-OHdG, indicating possible lipid peroxidation/cell damage or degenerative disease in some participants. MDA and 8-OHdG were highest in age group 21-60. The present study showed a significant sex difference with higher levels of urinary OH-PAHs in females than males.

Assessment of Genotoxic Effects of Pendimethalin in Chinese Hamster Over Cells by the Single Cell Gel Electrophoresis (Comet) Assay

OBJECTIVES

Pendimethalin (N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzeneamine) is a dinitroaniline herbicide compound which selectively controls weeds. It is a cell division and growth inhibitor. It descends plants in a short time after seedling. It is a soil and water pollutant due to the widespread use of formulations in Turkey and around the world. Pendimethalin is manufactured in and imported by Turkey. Pendimethalin is a slightly toxic compound that is classified in toxicity class 3 by the United States Environmental Protection Agency (USEPA). Even though it is classified as group C (human possible carcinogen) compound by the USEPA, there are limited number of studies about its genotoxic effects. The aim of this study was to evaluate in vitro genotoxic effects of different concentrations of pendimethalin in Chinese hamster over (CHO) cells by the single cell gel electrophoresis (comet) assay.

MATERIALS AND METHODS

The cells are incubated with 1, 10, 100, 1000 and 10000 µM concentrations of pendimethalin for 30 min at 37°C and DNA damage was compared with CHO cells untreated with pendimethalin. 50 µM hydrogen peroxide was used as positive control.

RESULTS

No significant cytotoxic effects were observed within the concentration ranges studied. The DNA damage in CHO cells was significantly increased in the pendimethalin concentrations of 1, 100, 1000 and 10000 µM, however, a significant decrease was observed in 10 µM pendimethalin concentration.

CONCLUSION

Our results show that 1-10000 µM concentrations of pendimethalin induce DNA damage in CHO cells, which was assessed by comet assay.

Bisphenol a induces autophagy and apoptosis concurrently involving the Akt/mTOR pathway in testes of pubertal SD rats

Bisphenol A (BPA), a typical endocrine disrupting chemical (EDC), has been proven to cause male reproductive toxicity. However, the precise mechanisms of this effect are still unclear. Puberty is a crucial period of reproductive development, and adolescents are more susceptible to xenobiotics. This research was designed to explore the mechanism of BPA toxicity on pubertal male reproduction. Rats were exposed to 0, 2, 10, 50 mg kg^-1 bw BPA, then the levels of sex hormones, oxidative stress, and semen quality were detected. HE staining, TUNEL assay and transmission electron microscopy were used to investigate the morphological changes, apoptosis, and autophagy in testes, respectively. Expressions of relevant genes and proteins were measured by RT-PCR, western blotting, and immunohistochemical staining. The results indicated that BPA exposure led to oxidative stress and endocrine disorders in pubertal male SD rats, caused apoptosis and autophagy in testes, and then damaged spermatogenesis ultimately. The Akt pathway was activated and the mTOR pathway was inhibited in the process. Taken together, BPA induced apoptosis and autophagy concurrently in pubertal testes, and this added a new layer to our understanding on male reproductive toxicity of BPA. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1977-1989, 2017.

S phase arrest in lymphocytes induced by urinary 1-hydroxypyrene and alcohol drinking in coke oven workers

Arrest of the cell cycle after DNA damage is believed to promote DNA repair. We aim to investigate the main factors affecting cell cycle arrest of lymphocytes in coke oven workers. A total of 600 workers were included in this study, and their urinary levels of four polycyclic aromatic hydrocarbons (PAH) metabolites, 8-hydroxydeoxyguanosine (8-OHdG), and cell cycle distribution were determined. Urinary PAH metabolites were significantly increased in coke oven workers ( p < 0.01). It was found that only urinary 2-hydroxynaphthalene and 1-hydroxypyrene showed significant positive linear dose–response effects on 8-OHdG in this study population ( ptrend = 0.025 and 0.017, respectively). The dose–response effect was also observed for smoking and drinking on 8-OHdG ( ptrend < 0.001 and 0.034, respectively). Multivariate logistic regression analysis revealed that high levels of urinary 1-hydroxypyrene were associated with a significantly increased risk of S phase arrest (odds ratio (OR) = 1.32, p = 0.03), so as heavy alcohol drinking (OR = 1.31, p = 0.02). Drinking can significantly modify the effects of urinary 1-hydroxypyrene on S phase arrest, during co-exposure to both heavy drinking and median or high 1-hydroxypyrene levels (OR = 3.31, 95% confidence interval (CI) = 1.21–7.63 and OR = 2.56, 95% CI = 1.08–6.06, respectively). Our findings demonstrate that coke oven workers with heavy drinking will cause S phase arrest so as to repair more serious DNA damage.

Supplementing oregano essential oil to boar diet with strengthened fish oil: Effects on semen antioxidant status and semen quality parameters

Previous research has shown benefits of dietary fish oil supplementation on semen quality of boars. However, little is known about how antioxidant protects lipid peroxidation on spermatozoa from n-3 polyunsaturated fatty acid (PUFA) addition. This study evaluated the effect of oregano essential oil (OEO) supplementation on semen antioxidant status and semen quality in boars fed a diet enriched with fish oil. Thirty-four mature boars of proven fertility, received daily 2.5 kg basal diet top-dressed with 45 g soybean oil and 15 g fish oil to meet the n-3 PUFA requirement of spermatozoa, randomly allocated to one of four groups supplemented with 100 mg α-tocopheryl acetate kg^-1 (control), or 250 or 500 or 750 mg OEO kg^-1 for 16 weeks. Semen was collected at weeks 0, 8, 12 and 16 for measurements of sperm production, motion characteristics, sperm α-tocopherol content, antioxidant enzyme activities, reactive oxygen species (ROS), DNA damage (8-hydroxydeoxyguanosine, 8-OHdG), lipoperoxidation (malondialdehyde, MDA) and seminal total antioxidant capacity (TAC). Sperm production and motion characteristics were similar (p > .05) among groups throughout the experimental week 16, but increased (p < .01) with experimental week. Although higher α-tocopherol content and superoxide dismutase (SOD) activities were in OEO group spermatozoa, feeding diet with 500 mg/kg OEO resulted in elevation in seminal TAC, decrease in sperm ROS, MDA and 8-OHdG than control group (p < .05). Overall, these results support the view that oregano essential oil has a positive effect on antioxidant capacity in boar when used fish oil.

[Necrozoospermia: From etiologic diagnosis to therapeutic management]

This review describes necrospermia, its diagnosis, causes and management. Sperm vitality is commonly assessed in the laboratory of reproductive biology, with the eosin test or with the hypo-osmotic swelling test. Necrospermia is defined by a percentage of living spermatozoa inferior to 58%, and can be related to male infertility. Several pathological mechanisms may be involved and can be classified either in testicular causes (hyperthyroidism, local hyperthermia, varicocele), or post-testicular causes (epididymal necrospermia, dysregulation of seminal plasma, adult polycystic kidney disease, vasectomy reversal, anti-sperm antibodies) or both (infection, toxic, age, spinal cord injury). The first treatment is to correct the underlying cause, if possible. Repetitive ejaculation has demonstrated to be effective as well. Many drugs would also improve the sperm vitality (antioxidants, non-and-steroidal anti-inflammatory drugs) but there is currently no guideline to recommend their use. With necrospermia, fertilization rates are lower but in vitro fertilization (IVF) with Intracytoplasmic sperm injection (ICSI) improves the chances of conception.

Oxidative DNA Damage to Sperm Cells and Peripheral Blood Leukocytes in Infertile Men

BACKGROUND Oxidative DNA damage is associated with male infertility. The aim of this study was to evaluate the oxidative DNA damage of sperm cells and blood leukocytes and to determine the levels of MDA and NO levels in seminal and blood plasma of idiopathic infertile men. MATERIAL AND METHODS The study enrolled 52 patients, including 30 infertile and 22 fertile men. MDA, NO, and 8-OHdG/106dG were estimated using spectrophotometry and high-pressure liquid chromatography (HPLC)-based methods in seminal and blood plasma. The association with the sperm parameters was assessed, particularly sperm counts and motility. RESULTS The mean sperm concentration and sperm motility of the fertile men were significantly higher than that of the infertile men. The mean MDA and NO concentration in the seminal and blood samples of the infertile men were higher than that of fertile men. Also, the mean numbers of sperm cells and leukocytes 8-OHdG/106dG of the infertile men were significantly higher than that of fertile men (p=0.04 and p<0.001, respectively). Sperm motility and sperm count were negatively correlated with leukocyte and sperm cell 8-OHdG/106dG ratio. However, progressive motility was significantly negatively correlated with sperm cell and leukocyte 8-OHdG/106dG ratio (R=-0.357, p=0.026; R=-0.388, p=0.024, respectively). CONCLUSIONS Oxidative stress is an important factor in male infertility. Therefore, biochemical detection of 8-OHdG/106dG in sperm cells and blood leukocytes may be an additional tool in the diagnosis of male infertility.

Utility of Dexrazoxane for the Attenuation of Epirubicin-Induced Genetic Alterations in Mouse Germ Cells

Dexrazoxane has been approved to treat anthracycline-induced cardiomyopathy and extravasation. However, the effect of dexrazoxane on epirubicin-induced genetic alterations in germ cells has not yet been reported. Thus, the aim of this study was to determine whether dexrazoxane modulates epirubicin-induced genetic damage in the germ cells of male mice. Our results show that dexrazoxane was not genotoxic at the tested doses. Furthermore, it protected mouse germ cells against epirubicin-induced genetic alterations as detected by the reduction in disomic and diploid sperm, spermatogonial chromosomal aberrations, and abnormal sperm heads. The attenuating effect of dexrazoxane was greater at higher dose, indicating a dose-dependent effect. Moreover, sperm motility and count were ameliorated by dexrazoxane pretreatment. Epirubicin induced marked biochemical changes characteristic of oxidative DNA damage including elevated 8-hydroxy-2'-deoxyguanosine levels and reduction in reduced glutathione. Pretreatment of mice with dexrazoxane before epirubicin challenge restored these altered endpoints. We conclude that dexrazoxane may efficiently mitigate the epirubicin insult in male germ cells, and prevent the enhanced risk of abnormal reproductive outcomes and associated health risks. Thus, pretreating patients with dexrazoxane prior to epirubicin may efficiently preserve not only sperm quality but also prevent the transmission of genetic damage to future generations.

The intracellular concentration of homocysteine and related thiols is negatively correlated to sperm quality after highly effective method of sperm lysis

The aims of this study were to determine concentrations of total homocysteine, cysteine, cysteinylglycine and glutathione in spermatozoa, seminal fluid and blood plasma and to analyse their relationships with sperm parameters. For this reason, a new highly effective method of spermatozoa lysis was developed, using methanol, freezing and subsequent thawing in ultrasonic bath. An HPLC-FD assay was conducted on thiols concentrations in lysed spermatozoa, seminal fluid and blood plasma. Concentrations of thiols in spermatozoa were significantly lower in men with normozoospermia than in samples with pathological semen parameters. Statistical analysis found significant correlations between thiol concentrations in spermatozoa and semen parameters, while the same analysis with thiol concentrations in seminal fluid was substantially less powerful. Only cysteinylglycine concentrations in seminal fluid significantly correlated with pathological semen parameters. No significant differences or correlations were found with blood plasma concentrations.