Reactive oxygen species generation and human spermatozoa: the balance of benefit and risk

Intrauterine insemination with ovarian stimulation versus expectant management for unexplained infertility (TUI): a pragmatic, open-label, randomised, controlled, two-centre trial

BACKGROUND

Women with unexplained infertility are often offered intrauterine insemination (IUI) with ovarian stimulation as an alternative to in-vitro fertilisation (IVF). However, little evidence exists that IUI is an effective treatment. In 2013, the UK National Institute for Health and Care Excellence recommended that IUI should not be routinely offered for couples with unexplained infertility.

METHODS

For this pragmatic, open-label, randomised, controlled, two-centre study, we enrolled women attending two fertility clinics in New Zealand with unexplained infertility and an unfavourable prognosis of natural conception. Participants were randomly assigned (1:1) using a computer-generated randomisation sequence, prepared by an independent statistician, to either three cycles of IUI with ovarian stimulation (with either oral clomifene citrate [50-150 mg, days 2-6] or oral letrozole [2·5-7·5 mg, days 2-6], with choice of ovarian stimulation made by the clinic) or three cycles of expectant management (couples advised to be sexually active around the likely time of ovulation and provided with a diary to record the first day of each menstrual cycle and dates of sexual activity) in blocks of four, six, and ten, without stratification. The participating couple and the clinicians were informed of treatment allocation. The primary outcome was cumulative livebirth rate in the intention-to-treat population. The safety analyses were done in the intention-to-treat population. This study was prospectively registered with the Australian and New Zealand Clinical Trials Register, number ACTRN12612001025820.

FINDINGS

Between March 12, 2013, and May 12, 2016, we randomly assigned 101 women to IUI with ovarian stimulation and 100 to expectant management, all of whom were included in the primary efficacy analysis and safety analyses. Women assigned to IUI had a higher cumulative livebirth rate than women assigned to expectant management (31 [31%] livebirths among 101 women vs nine [9%] livebirths among 100 women; risk ratio [RR] 3·41, 95% CI 1·71-6·79; p=0·0003). Of 31 livebirths in the IUI group, 23 resulted from IUI cycles and eight were conceived without assistance before or between IUI cycles. Of nine livebirths in the expectant management group, one patient was pregnant from IUI with ovarian stimulation at study entry and one had received off-protocol treatment (IVF). Two sets of twins were born, both in the IUI group (one from a cancelled cycle for over-response).

INTERPRETATION

IUI with ovarian stimulation is a safe and effective treatment for women with unexplained infertility and an unfavourable prognosis for natural conception.

FUNDING

Auckland Medical Research Foundation, Evelyn Bond Fund of Auckland District Health Board, Mercia Barnes Trust of Royal Australian and New Zealand College of Obstetricians and Gynaecologists, Maurice and Phyllis Paykel Trust, and The Nurture Foundation for Reproductive Research.

Evaluation of antioxidant potentials of different solvent-fractions of Dialium indium (African Black velvet tamarind) fruit pulp - in vitro

Plant phytonutrients have been harnessed for their various curative properties both in vitro and in vivo. In this study African black velvet tamarind (ABVT) fruit pulp was evaluated for it antioxidant potentials using chloroform and hexane fractions through different antioxidant parameters. In the results; total phenolic contents quantified in mg GAE/dried sample in chloroform and hexane extracts were; 14.57 ±5.85 and 9.78 ±4.61, total flavonoid contents in chloroform and hexane extracts as; 48.58 ±0.00 and 27.35 ±0.00 while the FRAP (µg AAE.g-1 dried sample) was lower in chloroform (298.10 ±0.00) than hexane extracts (1029.81 ±0.00). More also, ability of varied concentrations of the extracts (with their IC50) to cause inhibition against Fe2+-induced MDA that was determined by TBARS in rat's brain and liver tissue homogenates, Fe2+-chelating ability and other antioxidant assays, showed an appreciable significant (p <0.05) difference. The various antioxidant properties showed by ABVT has indicated that, if the pulp is incorporated in diet, it could serve as an alternative in managing various ROS-induced degenerative ailments as it has been clearly demonstrated in the protection of brain and liver homogenates from Fe2+-induced oxidative stress. 

Cryoprotective effect of glutamine, taurine, and proline on post-thaw semen quality and DNA integrity of donkey spermatozoa

This study was conducted to evaluate the effect of amino acid addition to semen on post-thaw quality of donkey spermatozoa. Eighteen ejaculates were pooled and divided into aliquots which were cryopreserved in Gent A^® containing 1% ethylene glycol (Gent-EG) and supplemented with 0 (as control), 20, 40, or 60 mM of glutamine, proline, or taurine. The greatest concentration (60 mM) of glutamine and taurine resulted in greater (P < 0.001) post-thaw sperm motility. Amino acid supplementation did not improve (P > 0.05) sperm morphology and membrane plasma integrity compared with the control samples. Whereas, improvement (P < 0.05) of acrosome integrity was observed with use of 60 mM glutamine. After thawing, there were no differences (P > 0.05) in the sperm DNA fragmentation index (sDFI) among treatments. The 60 mM glutamine and 40 mM taurine treatments, however, resulted in a reduction (P < 0.05) in sDFI values in the first 6 h of semen incubation, compared with the control samples. At 24 h, the sDFI values were less (P < 0.05) in all supplemented as compared with control samples, except for the 20 mM proline treatment group. In conclusion, supplementation of the Gent-EG extender with glutamine or taurine at 60 mM improved post-thaw donkey sperm quality. The addition of proline to the freezing extender, however, did not provide any significant enhancement in sperm quality, compared with the control group.

Laboratory assessment of oxidative stress in semen

Objectives

To evaluate different laboratory assessments of oxidative stress (OS) in semen and identify a cost-efficient and highly sensitive instrument capable of providing a comprehensive measure of OS in a clinical setting, as early intervention and an accurate diagnostic test are important because they help maintain a balance of free radicals and antioxidants; otherwise, excessive OS could lead to sperm damage and result in male infertility.

Materials and methods

A systematic literature search was performed through a MedLine database search using the keywords ‘semen’ AND ‘oxygen reduction potential’. We also reviewed the references of retrieved articles to search for other potentially relevant research articles and additional book chapters discussing laboratory assessments for OS, ranging from 1994 to 2017. A total of 29 articles and book chapters involving OS-related laboratory assays were included. We excluded animal studies and articles written in languages other than English.

Results

Direct laboratory techniques include: chemiluminescence, nitro blue tetrazolium, cytochrome C reduction test, fluorescein probe, electron spin resonance and oxidation–reduction potential (ORP). Indirect laboratory techniques include: measurement of Endtz test, lipid peroxidation, chemokines, antioxidants/micronutrients/vitamins, ascorbate, total antioxidant capacity, or DNA damage. Each of these laboratory techniques has its advantages and disadvantages.

Conclusion

Traditional OS laboratory assessments have their limitations. Amongst the prevalent laboratory techniques, ORP is novel and better option as it can be easily used in a clinical setting to provide a comprehensive review of OS. However, more studies are needed to evaluate its reproducibility across various laboratory centres.

Valores morfométricos en larvas de Yamú <i>Brycon amazonicus</i> (Pisces: Characidae) obtenidas con semen fresco y crioconservado

Con el propósito de evaluar diferencias en el desarrollo corporal, el crecimiento y la sobrevivencia de larvas de yamú (Brycon amazonicus) obtenidas a partir de la fertilización de oocitos con semen fresco (SF) y semen crioconservado (SC), machos y hembras de la especie fueron inducidos hormonalmente con extracto de hipófisis de carpa. El semen obtenido fue evaluado y diluido en una solución de yema de huevo, glucosa y dimetilsulfoxido y congelado en vapores de nitrógeno. Las larvas fueron obtenidas de la seminación en seco de oocitos obtenidos de una misma hembra, con semen fresco o crioconservado y evaluadas desde la eclosión (0 horas) hasta 60 horas posteclosión (HPE). Se determinó la longitud total (LT), longitud notocordal (LN), el volumen del saco vitelino (VSV) y la sobrevivencia desde 35 HPE hasta 60 HPE. Para LT sólo hubo diferencias significativas (p < 0,05) a la 42 y 54 HPE, siendo mayores las larvas obtenidas de SC (6,5 ± 0,04 y 6,8 ± 0,04 mm, respectivamente). La LN fue significativamente diferente a las 0, 3 y 54 HPE, con un mayor desarrollo de larvas obtenidas de SF en la hora 0 (3,3 ± 0,02 mm) y para SC en la 3 y 54 HPE (4,1 ± 0,05 y 6,6 ± 0,04 mm, respectivamente). El VSV a la 9 HPE fue mayor para SF (0,6 ± 0,01 mm3). Con relación a la sobrevivencia no hubo diferencias entre los dos tratamientos. En conclusión, el desarrollo corporal, crecimiento y la sobrevivencia de larvas de yamú obtenidas con SF y SC bajo las condiciones experimentales descritas anteriormente no varía significativamente para la LT, LN y VSV hasta la 60 HPE.

Relationship of antioxidant system and reactive oxygen species with clinical semen parameters in infertile men

Aims and Objectives:

To determine the correlation of antioxidant system and reactive oxygen species with clinical parameters in infertile semen samples.

Materials and Methods:

Semen sample of fifty infertile men were divided into three groups: (1) Group I - Normospermic (count >15 million/ml), Group II - Asthenospermic (motility <32%), and Group III - Oligospermic (counts <15 million/ml) subjects based on the sperm count and sperm motility. The samples were also divided into two groups: (1) Group IV with semen pH >7.2 (25 samples) and Group V - Semen pH <7.2 (25 samples). The grouping was based on the WHO guideline for semen analysis (12). The semen antioxidant parameters like glucose-6-phosphate dehydrogenase (G-6-PDH) (spectrophotometric method Kornberg and Horecker, 1955). Catalase (Maehly and Chance 1954), glutathione peroxidase (GPX) (Rotruck method), glutathione (GSH) (dithiobisnitro-benzoate method), superoxide dismutase (SOD) (direct method), and malondialdehyde (MDA) (thiobarbituric acid reactive substances assay kit method) were investigated. Mann–Whitney U-test was applied to compare the findings.

Results:

Of fifty semen samples there were 12 normospermic (sperm concentration ≥15 × 10⁶/ml of ejaculates), 24 asthenospermic (sperm motility ≤32%), and 14 oligospermic (sperm concentration ≤15 × 10⁶/ml of ejaculates) subjects. Results suggested that all asthenospermic males were found to have reduced motility and viability when compared with normospermic and oligospermic subjects. Activity of antioxidant parameters such as G-6-PDH, GPX, GSH, and SOD was decreased in case of asthenospermic subjects. The concentration of MDA was increased significantly (P < 0.001) in semen of asthenospermic subjects compared to normospermic and oligospermic subjects.

Conclusion:

The current study concludes that there is a significant relationship of ROS and semen parameters. Further studies will be needed in such subjects regarding role of effectiveness of dietary antioxidants in improving semen qualities.

Induced sub-lethal oxidative damage affects osmotic tolerance and cryosurvival of spermatozoa

If the physiological balance between production and scavenging of reactive oxygen species (ROS) is shifted towards production of ROS this may result in accumulation of cell damage over time. In this study stallion spermatozoa were incubated with xanthine and xanthine oxidase (X–XO) to artificially generate defined levels of superoxide and hydrogen peroxide resulting in sub-lethal oxidative damage. The effects of X–XO treatment on various sperm characteristics were studied. Special emphasis was placed on sperm osmotic tolerance pre-freeze and its correlation with cryosurvival, given that cryopreservation exposes cells to osmotic stress. ROS accumulation occurred predominantly in the sperm midpiece region, where the mitochondria are located. Exposing spermatozoa to increasing X–XO concentrations resulted in a dose-dependent decrease in sperm motility. Percentages of plasma membrane-intact spermatozoa were not affected, whereas stability of membranes towards hypotonic stress decreased with increasing levels of induced oxidative stress. Infrared spectroscopic studies showed that X–XO treatment does not alter sperm membrane phase behaviour. Spermatozoa exposed to higher oxidative stress levels pre-freeze exhibited reduced cryosurvival. Centrifugation processing and addition of catalase were found to have little beneficial effect. Taken together, these results show that treatment of spermatozoa with X–XO resulted in different levels of intracellular ROS, which decreased sperm osmotic tolerance and cryosurvival.

The impact of semen processing on sperm parameters and pregnancy rates after intrauterine insemination

BACKGROUND

The objective of this retrospective study was to evaluate the effect of semen processing on computer analyzed semen parameters and pregnancy rates after intrauterine insemination (IUI).

METHODS

Over a two-year period, a total of 981 couples undergoing 2231 IUI cycles were evaluated and the freshly collected non-donor semen was analyzed before and after density gradient centrifugation (DGC).

RESULTS

DGC led to significant increases in sperm concentration by 66±74 ×106/mL (P=0.0001), percentage of motile sperm by 24±22% (P=0.0001), concentration motile by 27±58 ×106/mL (P=0.0001), and forward sperm progression by 18±14 µ/s (P=0.0001). In 95% of cases, there was a decrease in the total motile sperm count (TMSC), with an average decrease of 50±124% compared to pre-processed samples (P=0.0001). Importantly, the decrease in TMSC did not negatively affect pregnancy rates (P=0.45).

CONCLUSIONS

This study proves that DGC leads to significant increases in most sperm parameters, with the exception of TMSC. Remarkably, the decrease in TMSC did not affect the pregnancy rate. This should reassure clinicians when the TMSC is negatively affected by processing.

Effect of green tea (Camellia sinensis) extract and pre-freezing equilibration time on the post-thawing quality of ram semen cryopreserved in a soybean lecithin-based extender

The aim of this study was to determine the effect of Camellia sinensis extract as antioxidant supplement and pre-freezing equilibration times in a soybean lecithin extender for freezing ram semen. In this study, a total of 20 ejaculates were collected from four Ghezel rams and diluted with extenders (1.5% soybean lecithin, 7% glycerol) containing no supplements (control) and Camellia sinensis extract (5, 10, and 15 mg/L) and cryopreserved, immediately after thermal equilibrium was reached at 5 °C (0 h), or 4 h after equilibration. Sperm motility characteristics, membrane integrity, abnormal morphology, mitochondria activity, apoptotic status, MDA and antioxidant activities (GPx, SOD and total antioxidant capacity (TAC)) were evaluated following freeze-thawing. Camellia sinensis extract at level 10 mg/L led to the highest total and progressive motilities percentages, in comparison to other treatments (P < 0.05). Our results showed that Camellia sinensis extract at level of 5 and 10 mg/L led to higher plasma membrane integrity, mitochondria activity and Total antioxidant capacity (TAC) in comparison to the level of 15 mg/L and control group (P < 0.05). Camellia sinensis extract at 10 mg/L level produced the highest percentage of live spermatozoa and the lowest apoptotic spermatozoa in comparison to all treatments (P < 0.05). In addition, level of MDA formation significantly decreased at this concentration, 10 mg/L, compared to all treatments (P < 0.05). No differences (P > 0.05) were observed between equilibration times (0 h vs. 4 h) for sperm samples incubated with or without different concentrations of Camellia sinensis extract. In conclusion, addition of Camellia sinensis extract at level of 10 mg/L can improve post-thawing quality of ram semen cryopreserved in a soybean lecithin extender. However, further research is needed to standardize the process of Camellia sinensis extraction and specially for identifying which compounds are responsible of its beneficial effect on ram sperm cryopreservation.

Specialized sperm function tests in varicocele and the future of andrology laboratory

Varicocele is a common medical condition entangled with many controversies. Though it is highly prevalent in men with infertility, still it marks its presence in males who do have normal fertility. Determining which patients are negatively affected by varicocele would enable clinicians to better select those men who benefitted the most from surgery. Since conventional semen analysis has been limited in its ability to evaluate the negative effects of varicocele on fertility, a multitude of specialized laboratory tests have emerged. In this review, we examine the role and significance of specialized sperm function tests with regards to varicocele. Among the various tests, analysis of sperm DNA fragmentation and measurements of oxidative stress markers provide an independent measure of fertility in men with varicocele. These diagnostic modalities have both diagnostic and prognostic information complementary to, but distinct from conventional sperm parameters. Test results can guide management and aid in monitoring intervention outcomes. Proteomics, metabolomics, and genomics are areas; though still developing, holding promise to revolutionize our understanding of reproductive physiology, including varicocele.

Outdoor air pollution and sperm quality

Exposure to air pollution has been clearly associated with a range of adverse health effects, including reproductive toxicity, but its effects on male semen quality are still unclear. We performed a systematic review (up to June 2016) to assess the impact of air pollutants on sperm quality. We included 17 semi-ecological, panel, and cohort studies, assessing outdoor air pollutants, such as PM2.5, PM10, NOx, SO2, and O3, and their effects on DNA fragmentation, sperm count, sperm motility, and sperm morphology. Thirteen studies assessed air pollution exposure measured environmentally, and six used biomarkers of air pollution exposure (two did both). We rated the studies using the Newcastle-Ottawa Scale and assessed with the exposure method. Taking into account these factors and the number of studies finding significant results (positive or negative), the evidence supporting an effect of air pollution on DNA fragmentation is weak but suggestive, on sperm motility is limited and probably inexistent, on lower sperm count is inconclusive, and on sperm morphology is very suggestive. Because of the diversity of air pollutants and sperm parameters, and the studies' designs, we were unable to perform a meta-analysis. In summary, most studies concluded that outdoor air pollution affects at least one of the four semen quality parameters included in the review. However, results lack consistency, and furthermore, studies were not comparable. Studies using standardized air pollution and semen measures are required to obtain more reliable conclusions.

PROSPERO REGISTRATION NUMBER

CRD42015007175.

Are oxidative stress markers associated with unexplained male infertility?

Male infertility can be responsible for up to 20% of the cases attending fertility consultation facilities; nonetheless, the underlying molecular mechanisms that could explain it are still elusive. Therefore, we aimed to evaluate conventional and functional parameters of semen samples from patients who presented with male infertility of unknown origin. Conventional semen parameters and functional parameters (i.e. intracellular reactive oxygen species production, mitochondrial membrane potential, sperm chromatin structure assay, sperm membrane lipid peroxidation and antioxidant capacity of seminal plasma) were evaluated on semen samples from 54 healthy donors, 23 patients with idiopathic infertility and 34 fertile controls. No significant differences were observed in the conventional seminal parameters between the fertile and infertile men. However, increased intracellular reactive oxygen species (ROS) production and DNA fragmentation were observed in the infertile patients compared to the fertile group. Alterations in intracellular ROS production and DNA fragmentation could be associated with male idiopathic infertility. These parameters could eventually distinguish both groups more accurately than the conventional parameters. Our current results are encouraging, and the efficacy of these parameters in the clinical settings needs to be further assessed to establish their predictive potential as a marker of unexplained male infertility.

Evaluation of the Efficiency of Two Different Freezing Media and Two Different Protocols to Preserve Human Spermatozoa from Cryoinjury

It is universally recognized that cryopreservation impairs sperm quality. In order to improve postthawing sperm survival and motility, media of different composition and different protocols have been proposed. However, no clear evidence is available to understand which are the most efficient protocol and medium for sperm cryopreservation. The present study evaluates the efficiency of two different cryopreservation protocols and two common freezing media (FM) containing different cryoprotectants (CPs), TEST Yolk Buffer (TYB) and Sperm Freeze (SF), to preserve human sperm quality. Our data suggest that TYB is better than SF both in terms of postthaw viability and in terms of progressive motility, while the direct addition of FM to the sperm sample resulted in the most efficient protocol in terms of postthaw viability but not in terms of progressive motility.

Developmental origins of male subfertility: role of infection, inflammation, and environmental factors

Male gamete development begins with the specification of primordial cells in the epiblast of the early embryo and is not complete until spermatozoa mature in the epididymis of adult males. This protracted developmental process involves extensive alteration of the paternal germline epigenome. Initially, epigenetic reprogramming in fetal germ cells results in removal of most DNA methylation, including parent-specific epigenetic information. The germ cells then establish sex-specific epigenetic information through de novo methylation and undergo spermatogenesis. Chromatin in haploid germ cells is repackaged into protamines during spermiogenesis, providing further widespread epigenetic reorganization. Finally, after fertilization, epigenetic reprogramming in the preimplantation embryo is necessary for regaining totipotency. These events provide substantial windows during which epigenetic errors either may be corrected or may occur in the germline. There is now increasing evidence that environmental factors such as exposure to toxicants, the parents' and individual's diet, and even infectious and inflammatory events in the male reproductive tract may influence epigenetic reprogramming. This, together with other damage inflicted on the germline chromatin, may result in negative consequences for fertility and health. Large epidemiological birth cohort studies have yielded insight into possible causative environmental factors. Together with experimental animal studies, a clearer view of environmental impacts on fetal development and their intergenerational and even transgenerational effects on reproductive health has emerged and is reviewed in this article.

Paternal under-nutrition programs metabolic syndrome in offspring which can be reversed by antioxidant/vitamin food fortification in fathers

There is an ever increasing body of evidence that demonstrates that paternal over-nutrition prior to conception programs impaired metabolic health in offspring. Here we examined whether paternal under-nutrition can also program impaired health in offspring and if any detrimental health outcomes in offspring could be prevented by micronutrient supplementation (vitamins and antioxidants). We discovered that restricting the food intake of male rodents reduced their body weight, fertility, increased sperm oxidative DNA lesions and reduced global sperm methylation. Under-nourished males then sired offspring with reduced postnatal weight and growth but somewhat paradoxically increased adiposity and dyslipidaemia, despite being fed standard chow. Paternal vitamin/antioxidant food fortification during under-nutrition not only normalised founder oxidative sperm DNA lesions but also prevented early growth restriction, fat accumulation and dyslipidaemia in offspring. This demonstrates that paternal under-nutrition reduces postnatal growth but increases the risk of obesity and metabolic disease in the next generation and that micronutrient supplementation during this period of under-nutrition is capable of restoring offspring metabolic health.

Fourier transform infrared spectroscopic analysis of sperm chromatin structure and DNA stability

Sperm chromatin structure and condensation determine accessibility for damage, and hence success of fertilization and development. The aim of this study was to reveal characteristic spectral features coinciding with abnormal sperm chromatin packing (i.e., DNA-protein interactions) and decreased fertility, using Fourier transform infrared spectroscopy. Chromatin structure in spermatozoa obtained from different stallions was investigated. Furthermore, spermatozoa were exposed to oxidative stress, or treated with thiol-oxidizing and disulfide-reducing agents, to alter chromatin structure and packing. Spectroscopic studies were corroborated with flow cytometric analyses using the DNA-intercalating fluorescent dye acridine orange. Decreased fertility of individuals correlated with increased abnormal sperm morphology and decreased stability toward induced DNA damage. Treatment with the disulfide reducing agent dithiothreitol resulted in increased sperm chromatin decondensation and DNA accessibility, similar as found for less mature epididymal spermatozoa. In situ infrared spectroscopic analysis revealed that characteristic bands arising from the DNA backbone (ν1230, ν1086, ν1051 cm(-1) ) changed in response to induced oxidative damage, water removal, and decondensation. This coincided with changes in the amide-I region (intensity at ν1620 vs. ν1640 cm(-1) ) denoting concomitant changes in protein secondary structure. Reduction in protein disulfide bonds resulted in a decreased value of the asymmetric to symmetric phosphate band intensity (ν1230/ν1086 cm(-1) ), suggesting that this band ratio is sensitive for the degree of chromatin condensation. Moreover, when analyzing spermatozoa from different individuals, it was found that the asymmetric/symmetric phosphate band ratio negatively correlated with the percentage of morphologically abnormal spermatozoa.

Male obesity and subfertility, is it really about increased adiposity?

The prevalence of overweight and obesity in reproductive-aged men is increasing worldwide, with >70% of men >18 years classified as overweight or obese in some western nations. Male obesity is associated with male subfertility, impairing sex hormones, reducing sperm counts, increasing oxidative sperm DNA damage and changing the epigenetic status of sperm. These changes to sperm function as a result of obesity, are further associated with impaired embryo development, reduced live birth rates and increased miscarriage rates in humans. Animal models have suggested that these adverse reproductive effects can be transmitted to the offspring; suggesting that men's health at conception may affect the health of their children. In addition to higher adiposity, male obesity is associated with comorbidities, including metabolic syndrome, hypercholesterolemia, hyperleptinemia and a pro-inflammatory state, all which have independently been linked with male subfertility. Taken together, these findings suggest that the effects of male obesity on fertility are likely multifactorial, with associated comorbidities also influencing sperm, pregnancy and subsequent child health.

Does reducing gamete co-incubation time improve clinical outcomes: a retrospective study

PURPOSE

The objective of this retrospective study was to determine whether patients undergoing in vitro fertilization (IVF) benefit from reducing the gamete co-incubation time.

METHODS

Patients (n = 570) were enrolled, including 281 patients in the reduced incubation time group (2-h incubation) and 289 patients in the standard IVF group (18-h incubation).

RESULTS

The observed outcomes, including the clinical pregnancy rate (CPR), implantation rate (IR), live birth rate (LBR), and miscarriage rate (MR), were similar between the two groups. When the data were divided into two subgroups based on the maternal age (≤30 and >30 years), the rates of top-quality embryos (30.83 vs. 25.89 %; p = 0.028), CPR (66.67 vs. 42.11 %; p = 0.013), and IR (41.90 vs. 31.25 %, p = 0.019) of the 2-h incubation group were significantly higher in the younger subgroup. However, for older patients, only a lower MR (7.59 vs. 20.83 %; p = 0.019) was achieved. Reducing the time of incubation still improved the CPR (OR = 1.993, 95 % CI 1.141-3.480) and MR (OR = 3.173, 95 % CI 1.013-9.936) in the younger and older subgroups, respectively, after it was adjusted for potential confounders.

CONCLUSIONS

Reducing incubation time improves the clinical results of IVF, although the LBR is not statistically different between the 2- and 18-h incubation time groups. And the specific clinical outcomes of reducing incubation time varied between the >30-year-old and the ≤30-year-old.

Firpronil induced spermotoxicity is associated with oxidative stress, DNA damage and apoptosis in male rats

The present study is the first to investigate and characterize the fipronil (FPN) induced spermotoxicity in male rats. Male rats were orally given FPN (2.5, 5.0 and 10 mg/kg/day) for 4 weeks. Epididymal sperms were collected and remaining testis was processed for histopathological evaluation. FPN treatment significantly reduced sperm density, motility, viability and per cent intact acrosome along with concomitant increase in spermatozoa abnormalities. Exposure of FPN caused excessive ROS generation, lipid peroxidation and alteration in mitochondrial membrane potential leading to apoptosis of spermatozoa in dose dependent manner. Higher FPN doses (5 and 10 mg/kg) markedly reduced the DNA integrity of spermatozoa. These data suggest that FPN causes male reproductive toxicity through oxidative stress induced DNA damage and apoptosis of spermatozoa.

Exposure to ambient air pollution--does it affect semen quality and the level of reproductive hormones?

BACKGROUND

Ambient air pollution has been associated with a variety of reproductive disorders. However, a limited amount of research has been conducted to examine the association between air pollution and male reproductive outcomes, specifically semen quality.

AIM

The present study was designed to address the hypothesis that exposure to fluctuating levels of specific air pollutants adversely affects sperm parameters and the level of reproductive hormones.

SUBJECTS AND METHODS

The study population consisted of 327 men who were attending an infertility clinic in Łodź, Poland for diagnostic purposes and who had normal semen concentration of 15-300 mln/ml. All participants were interviewed and provided a semen sample. Air quality data were obtained from AirBase database.

RESULTS

The statistically significant association was observed between abnormalities in sperm morphology and exposure to all examined air pollutants (PM10, PM2.5, SO2, NOX, CO). Exposure to air pollutants (PM10, PM2.5, CO, NOx) was also negatively associated with the level of testosterone. Additional exposure to PM2.5, PM10 increase the percentage of cells with immature chromatin (HDS).

CONCLUSIONS

The present study provides suggestive evidence of an association between ambient air pollution and sperm quality. Further research is needed to explore this association in more detail. Individual precise exposure assessment would be needed for more detailed risk characterization.

Effect of ethanol induced mild stress on post-thawed bull sperm quality

This study was performed to investigate the effect of sub-lethal exposure of bull semen to ethanol on the post-thaw spermatozoa quality. Semen samples (n=24, 6 ejaculates/bull) from 4 Holstein bulls were collected and pooled. Pooled samples were divided into 4 equal parts and each part was frozen after being diluted with Optidyl® extender containing 0 (O-E0), 0.03 (O-E3), 0.09 (O-E9) and 0.15 (O-E15) % (v/v) absolute ethanol. Sperm motility and velocity, plasma membrane integrity and functionality, mitochondrial activity, malondialdehyde concentration, and apoptosis status were evaluated after thawing. A higher percentage of total motility was observed in the O-E9 group as compared to the O-E0, O-E3 and O-E15 groups (p<0.05). Also, plasma membrane integrity was higher (p<0.05) in the O-E9 group compared to the O-E3, and O-E15 groups. However, the difference between the O-E9 and O-E0 groups was not significant (p>0.05). In terms of the proportion of sperm abnormality and plasma membrane functionality no differences (p>0.05) were observed between the groups. Our results revealed that malondialdehyde level was lower in ethanol treated (O-E3, O-E9 and O-E15) groups compared to the O-E0 group (p<0.05). Furthermore, the percentage of live spermatozoa with active mitochondria was higher in the O-E9 and O-E15 groups compared to the O-E0 and O-E3 groups (p<0.05). The O-E3 and O-E9 groups resulted in the highest and lowest percentage of apoptotic spermatozoa, respectively (p<0.05). The results of this study demonstrate that supplementation of semen extender with sub-lethal concentration of ethanol influences post-thawed bull sperm quality in a dose dependent manner.

Coenzyme Q₁₀, α-tocopherol, and oxidative stress could be important metabolic biomarkers of male infertility

Oxidative stress, decreased antioxidant capacity, and impaired sperm mitochondrial function are the main factors contributing to male infertility. The goal of the present study was to assess the effect of the per os treatment with Carni-Q-Nol (440 mg L-carnitine fumarate + 30 mg ubiquinol + 75 IU vitamin E + 12 mg vitamin C in each softsule) in infertile men on sperm parameters, concentration of antioxidants (coenzyme Q₁₀,  CoQ_10-TOTAL, γ, and α-tocopherols), and oxidative stress in blood plasma and seminal fluid. Forty infertile men were supplemented daily with two or three Carni-Q-Nol softsules. After 3 and 6 months of treatment, improved sperm density was observed (by 48.9% and 80.9%, resp.) and after 3-month treatment the sperm pathology decreased by 25.8%. Concentrations of CoQ_10-TOTAL (ubiquinone + ubiquinol) and α-tocopherol were significantly increased and the oxidative stress was decreased. In conclusion, the effect of supplementary therapy with Carni-Q-Nol showed benefits on sperm function in men, resulting in 45% pregnancies of their women. We assume that assessment of oxidative stress, CoQ_10-TOTAL, and α-tocopherol in blood plasma and seminal fluid could be important metabolic biomarkers in both diagnosis and treatment of male infertility.

Total antioxidant capacity and lipid peroxidation in semen of patient with hyperviscosity

Semen hyperviscosity (SHV) is one of the factors involved in deficiency in sperm function. This research aimed to evaluate seminal plasma total antioxidant capacity (TAC) and malondialdehyde (MDA) levels in infertile patients with hyperviscous and non-hyperviscous semen samples to understand whether hyperviscous semen is associated with oxidative damage in infertile subjects. In this cross sectional study, 59 semen samples were provided by fertile (n=12) individuals as control, infertile patients with normal viscosity (n=25) and infertile patients with hyperviscosity (n=22). After semen parameters examination, semen viscosity was studied by glass pipettes. Seminal plasma TAC and MDA levels were measured by ferric reducing of antioxidant power (FRAP) and thiobarbituric acid reaction (TBAR) methods, respectively. A probability less than 0.05 was considered statistically significant throughout the article. The mean of sperm parameters including: counts, motility and normal morphology in patients with hyperviscosity were significantly lower than those in non-hyperviscosity patients (p<0.05, p<0.01 and p<0.001, respectively). The mean of seminal plasma TAC value in seminal plasma of non-hyperviscosity patients (1710.31 ± 458.67 µmol/l) was significantly (p<0.01) higher than that of hyperviscosity group (1230.25 ± 352 µmol/l). A trend toward a higher mean of seminal plasma MDA value was estimated for hyperviscous group compared with non-hyperviscous (1.01 ± 0.41 nmol/ml vs. 0.94 ± 0.28 nmol/l); however, it was nonsignificant. Hyperviscous semen impairs seminal plasma TAC which is eventually associated with sperm membrane lipid peroxidation.

Heat shock protein 90 has roles in intracellular calcium homeostasis, protein tyrosine phosphorylation regulation, and progesterone-responsive sperm function in human sperm

Heat shock protein 90 plays critical roles in client protein maturation, signal transduction, protein folding and degradation, and morphological evolution; however, its function in human sperm is not fully understood. Therefore, our objective in this study was to elucidate the mechanism by which heat shock protein 90 exerts its effects on human sperm function. By performing indirect immunofluorescence staining, we found that heat shock protein 90 was localized primarily in the neck, midpiece, and tail regions of human sperm, and that its expression increased with increasing incubation time under capacitation conditions. Geldanamycin, a specific inhibitor of heat shock protein 90, was shown to inhibit this increase in heat shock protein 90 expression in western blotting analyses. Using a multifunctional microplate reader to examine Fluo-3 AM-loaded sperm, we observed for the first time that inhibition of heat shock protein 90 by using geldanamycin significantly decreased intracellular calcium concentrations during capacitation. Moreover, western blot analysis showed that geldanamycin enhanced tyrosine phosphorylation of several proteins, including heat shock protein 90, in a dose-dependent manner. The effects of geldanamycin on human sperm function in the absence or presence of progesterone was evaluated by performing chlortetracycline staining and by using a computer-assisted sperm analyzer. We found that geldanamycin alone did not affect sperm capacitation, hyperactivation, and motility, but did so in the presence of progesterone. Taken together, these data suggest that heat shock protein 90, which increases in expression in human sperm during capacitation, has roles in intracellular calcium homeostasis, protein tyrosine phosphorylation regulation, and progesterone-stimulated sperm function. In this study, we provide new insights into the roles of heat shock protein 90 in sperm function.

Oxidative stress in mouse sperm impairs embryo development, fetal growth and alters adiposity and glucose regulation in female offspring

Paternal health cues are able to program the health of the next generation however the mechanism for this transmission is unknown. Reactive oxygen species (ROS) are increased in many paternal pathologies, some of which program offspring health, and are known to induce DNA damage and alter the methylation pattern of chromatin. We therefore investigated whether a chemically induced increase of ROS in sperm impairs embryo, pregnancy and offspring health. Mouse sperm was exposed to 1500 µM of hydrogen peroxide (H₂O₂), which induced oxidative damage, however did not affect sperm motility or the ability to bind and fertilize an oocyte. Sperm treated with H₂O₂ delayed on-time development of subsequent embryos, decreased the ratio of inner cell mass cells (ICM) in the resulting blastocyst and reduced implantation rates. Crown-rump length at day 18 of gestation was also reduced in offspring produced by H₂O₂ treated sperm. Female offspring from H₂O₂ treated sperm were smaller, became glucose intolerant and accumulated increased levels of adipose tissue compared to control female offspring. Interestingly male offspring phenotype was less severe with increases in fat depots only seen at 4 weeks of age, which was restored to that of control offspring later in life, demonstrating sex-specific impacts on offspring. This study implicates elevated sperm ROS concentrations, which are common to many paternal health pathologies, as a mediator of programming offspring for metabolic syndrome and obesity.

The effects of 16 weeks of intensive cycling training on seminal oxidants and antioxidants in male road cyclists

OBJECTIVE

To examine the effects of 16 weeks of intensive cycling training on seminal reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), catalase, and total antioxidant capacity (TAC) in male road cyclists.

DESIGN

Repeated measures design.

SETTING

The Exercise Physiology Laboratory of the Urmia University.

PARTICIPANTS

Twenty-four healthy nonprofessional male road cyclists (aged 17-26 years) participated in this study.

INTERVENTIONS

All subjects participated in 16 weeks of intensive cycling training. The semen samples were collected, respectively, at baseline (T1), immediately (T2), 12 (T3), and 24 (T4) hours after the last training session in week 8; immediately (T5), 12 (T6), and 24 (T7) hours after the last training session in week 16; and 7 (T8) and 30 (T9) days after the last training session in week 16.

MAIN OUTCOME MEASURES

Total antioxidant capacity and SOD were measured by colorimetric assay. The levels of ROS were measured by a chemiluminescence assay. Malondialdehyde levels were measured by thiobarbituric acid reactive substance assay. Catalase was measured by monitoring the initial rate of disappearance of hydrogen peroxide (initial concentration 10 mM) at 240 nm.

RESULTS

The levels of seminal ROS and MDA increased (P < 0.008) and remained high after 30 days of recovery. The levels of seminal SOD, catalase, and TAC decreased (P < 0.008) and remained low after 30 days of recovery (P < 0.008).

CONCLUSIONS

Sixteen weeks of intensive cycling training may have deleterious consequences for spermatozoa and hence may affect sperm healthy parameters in male cyclists.