Relationship between reactive oxygen species production and lipid peroxidation in human sperm suspensions and their association with sperm function

In vitro effects of plasma rich in growth factors on human teratozoospermic semen samples

There is a correlation between teratozoospermia and production of reactive oxygen species leading to poor assisted reproductive techniques outcomes. This study aimed to examine the effect of plasma-rich in growth factors (PRGF) on teratozoospermic samples. Twenty-five teratozoospermic samples were included in this study. After sperm preparation, it was divided into four groups, including 0 (control), 1, 5, and 10% PRGF. Sperm motility, viability (eosin-nigrosin staining), morphology (Papanicolaou staining), DNA fragmentation (sperm chromatin dispersion test), mitochondrial membrane potential (JC-1 staining by flow cytometry), and lipid peroxidation (measurement of malondialdehyde, MDA) were evaluated before and after 1 h of incubation with or without PRGF. Our results showed that after 1 h of incubation, the addition of 1% PRGF improved sperm progressive motility (47.72 ± 13.76%) compared to the control group (17.36 ± 8.50%) (p < 0.001). Also, 1% PRGF preserved the sperm's total motility (77.50 ± 13.28% vs. 65.63 ± 19.03%, for 1% PRGF and control, respectively) and viability after incubation. The rate of normal sperm morphology was the same between different groups. Higher mitochondrial membrane potential and lower DNA fragmentation were also observed in sperm treated with different concentrations of PRGF compared to the control group, but the differences were non-significant. The MDA levels were significantly decreased in PRGF-treated groups compared to the control group (0.99 ± 0.62, 0.95 ± 0.33, 0.95 ± 0.79, and 1.49 ± 0.27 for 1% PRGF, 5% PRGF, 10% PRGF and control, respectively). Based on our results, it seems that PRGF incubation can improve sperm parameters and especially decrease the level of malondialdehyde as an indicator of oxidative stress, which is one of the main problems of teratozoospermic samples.

Oviductal fluid counterbalances the negative effect of high temperature on sperm in an ectotherm model

Global warming is affecting biodiversity; however, the extent to which animal reproductive processes respond to predicted temperature increments remains largely unexplored. The thermal environment has a pronounced impact on metabolic rates of ectotherms; therefore, an interesting question to assess is whether temperature increase might affect specific reproductive mechanisms like sperm performance in ectotherms. Moreover, in many species, oviductal fluid (OF) is known to regulate and maintain sperm quality; however, the role of OF in relation to the effects of high temperature on sperm remains unclear. Our aim was to experimentally test the effect of increased temperature on sperm velocity, swimming path and percentage of motility in neutral conditions at ejaculation (without OF) and in female's reproductive tract fluid (with OF), in a social ectotherm lizard model, Tropidurus spinulosus, which has specific thermal requirements for reproduction. Our results suggest that a rising temperature associated with global warming (+4°C) affects negatively sperm dynamics and survival. However, OF ameliorated the harmful effects of high temperature. This is an important point, as this study is the first to have tested the role of OF in preserving sperm from a warmer pre-fertilization environment. These results contribute to our understanding of how thermal environment changes might affect post-copulatory reproductive mechanisms. This article has an associated First Person interview with the first author of the paper.

Effect of Thawing Rates and Antioxidants on Semen Cryopreservation in Hu Sheep

Hu sheep is a valuable sheep breed in China, and semen cryopreservation of Hu sheep is important for sustainable development of the agri-food industry. This study aimed to evaluate the effect of thawing rate and antioxidants (procyanidins [PC] and mitoquinone [MitoQ]) on the quality and antioxidant enzyme activity of post-thaw sperm in Hu sheep. Our results showed that the highest sperm quality was obtained from the group thawed at 70°C for 5 seconds. Furthermore, addition of 150 nM MitoQ in the extender could enhance motility, integrity of the membrane and acrosome, and mitochondrial activity, whereas only sperm motility and membrane integrity were increased with 10 μg/mL of PC supplementation, compared with the control group. Meanwhile, both PC (10 μg/mL) and MitoQ (150 nM) supplementation increased the levels of superoxide dismutase and glutathione peroxidase and decreased the levels of reactive oxygen species and malondialdehyde. In conclusion, the optimal thawing protocol of semen cryopreservation in Hu sheep was 70°C for 5 seconds. MitoQ supplementation (150 mM) in the extender could improve sperm quality and reduce the level of oxidative stress in Hu sheep semen after cryopreservation. Further studies are needed to evaluate fertility of the post-thaw semen using MitoQ.

Does in vitro application of pentoxifylline have beneficial effects in assisted male reproduction?

Application of nonspecific phosphodiesterases inhibitors, such as pentoxifylline (PTX), is a strategy utilised to aid sperm selection from immotile sperm samples prior to ICSI. No extensive studies have yet been performed to verify the safety of the clinical outcomes of ICSI after PTX administration. In this article, we summarise the data reported in the literature that assess the implication of in vitro usage of PTX on sperm parameters, as well as clinical outcomes during assisted male reproduction programme.

The Impact of Di-2-Ethylhexyl Phthalate on Sperm Fertility

A growing number of studies point to reduced fertility upon chronic exposure to endocrine-disrupting chemicals (EDCs) such as phthalates and plasticizers. These toxins are ubiquitous and are often found in food and beverage containers, medical devices, as well as in common household and personal care items. Animal studies with EDCs, such as phthalates and bisphenol A have shown a dose-dependent decrease in fertility and embryo toxicity upon chronic exposure. However, limited research has been conducted on the acute effects of these EDCs on male fertility. Here we used a murine model to test the acute effects of four ubiquitous environmental toxins: bisphenol A (BPA), di-2-ethylhexyl phthalate (DEHP), diethyl phthalate (DEP), and dimethyl phthalate (DMP) on sperm fertilizing ability and pre-implantation embryo development. The most potent of these toxins, di-2-ethylhexyl phthalate (DEHP), was further evaluated for its effect on sperm ion channel activity, capacitation status, acrosome reaction and generation of reactive oxygen species (ROS). DEHP demonstrated a profound hazardous effect on sperm fertility by producing an altered capacitation profile, impairing the acrosome reaction, and, interestingly, also increasing ROS production. These results indicate that in addition to its known chronic impact on reproductive potential, DEHP also imposes acute and profound damage to spermatozoa, and thus, represents a significant risk to male fertility.

The Importance of Oxidative Stress in Determining the Functionality of Mammalian Spermatozoa: A Two-Edged Sword

This article addresses the importance of oxidative processes in both the generation of functional gametes and the aetiology of defective sperm function. Functionally, sperm capacitation is recognized as a redox-regulated process, wherein a low level of reactive oxygen species (ROS) generation is intimately involved in driving such events as the stimulation of tyrosine phosphorylation, the facilitation of cholesterol efflux and the promotion of cAMP generation. However, the continuous generation of ROS ultimately creates problems for spermatozoa because their unique physical architecture and unusual biochemical composition means that they are vulnerable to oxidative stress. As a consequence, they are heavily dependent on the antioxidant protection afforded by the fluids in the male and female reproductive tracts and, during the precarious process of insemination, seminal plasma. If this antioxidant protection should be compromised for any reason, then the spermatozoa experience pathological oxidative damage. In addition, situations may prevail that cause the spermatozoa to become exposed to high levels of ROS emanating either from other cells in the immediate vicinity (particularly neutrophils) or from the spermatozoa themselves. The environmental and lifestyle factors that promote ROS generation by the spermatozoa are reviewed in this article, as are the techniques that might be used in a diagnostic context to identify patients whose reproductive capacity is under oxidative threat. Understanding the strengths and weaknesses of ROS-monitoring methodologies is critical if we are to effectively identify those patients for whom treatment with antioxidants might be considered a rational management strategy.

Spironolactone reversed hepato-ovarian triglyceride accumulation caused by letrozole-induced polycystic ovarian syndrome: tissue uric acid-a familiar foe

Polycystic ovarian syndrome (PCOS) is a complex endocrine disease among women of reproductive age and is one of the main causes of infertility. Non-alcoholic fatty liver disease (NAFLD), the most prominent chronic liver disease in adults, is characterized by excess hepatic triglyceride (TG) accumulation. PCOS women have increased risk of NAFLD and uric acid has been documented to have a positive correlation with subclinical tissue damage and might be the link in the cystic. Spironolactone (SPL) is a mineralocorticoid receptor (MR) blocker that has been in wide clinical use for some decades. In this research, we investigated the effects of SPL on ovarian and hepatic tissue damage in experimental PCOS rats induced by letrozole (LET). A total of eighteen adult female Wistar rats were used for this study and the animals divided into 3 groups are treated with vehicle, LET (1 mg/kg), and LET+SPL (SPL; 0.25 mg/kg), p.o. once daily respectively for 21 uninterrupted days. Results showed that LET treatment induced features of PCOS characterized by increased plasma testosterone (T) and luteinizing hormone (LH) together with increased body weight. Abnormal ovarian and hepatic histomorphological changes were also observed with elevated uric acid (UA) and TG accumulation in both tissues respectively. Treatment with SPL however attenuated the elevated testosterone in the LET-induced PCOS model accompanied with a reversal in the observed ovarian and hepatic UA, TG accumulation, and altered histomorphological changes. Taken together, spironolactone reversed the PCOS-induced ovarian and hepatic tissue damage by suppressing tissue UA and TG accumulation.

CASA-Mot in mammals: an update

Sperm motility is one of the most widely used parameters of sperm quality. Computer-aided sperm motility analysis (CASA-Mot) systems were developed to reduce the subjectivity of sperm motility assessment, and have had broad scientific and practical acceptance. In this review, the sources of variation and current applications of this technology and its relationships with other sperm quality tests are described in detail. Despite remarkable advances in the technique, there is still great need for standardisation in many species, and the numerous factors that affect the results make it difficult to provide universally accepted criteria for classifying semen samples based on sperm motility characteristics. The main fields for CASA-Mot include the study of male fertility and pathologies, evaluation of the effects of physical and chemical agents, improvement of epidemiological survey studies, more precise calculation of seminal doses for farm animals, realisation of basic studies about sperm function, improvement of sperm technologies such as cryopreservation and quality control analysis. Numerous relationships have been established between CASA-Mot and other sperm quality tests, although most of these parameters are complementary. Future CASA-Mot systems will probably be able to integrate several sperm quality parameters with motility.

Very low dose spironolactone protects experimentally-induced polycystic ovarian syndrome from insulin-resistant metabolic disturbances by suppressing elevated circulating testosterone

Polycystic ovarian syndrome (PCOS) is the most common endocrinological disorder in women of reproductive age and hyperandrogenism is a prominent feature of PCOS resulting in infertility and increased risk of developing metabolic disorders including insulin resistance (IR), abdominal adiposity, glucose intolerance and cardiovascular diseases. Spironolactone (SPL), a non-selective mineralocorticoid receptor (MR) antagonist, has been in wide clinical use for several decades. In this study, we investigated the effects of SPL on IR and metabolic disturbances in letrozole-induced PCOS rats. Eighteen adults female Wistar rats were randomly divided into 3 groups and treated with vehicle, letrozole (LET; 1 mg/kg) and LET + SPL (SPL; 0.25 mg/kg), p.o. once daily for 21 consecutive days. Results showed that LET treatment induced PCOS characterised by elevated plasma testosterone and luteinizing hormone (LH) accompanied with increased body weight and visceral adiposity, IR, glucose intolerance, dyslipidemia and altered histomorphological ovaries. Treatment with SPL however attenuated the elevated testosterone in LET-induced PCOS model accompanied with a reversal in all the observed alterations. Taken together, analysis of the physical, biochemical and histological evidences shows that the protective effect of this very low dose spironolactone may be through its anti-androgenic mechanism.

Protective effects of GABA against metabolic and reproductive disturbances in letrozole induced polycystic ovarian syndrome in rats

Background

PCOs is a heterogeneous disorder with anovulation/oligo ovulation usually taken as oligo menorrhoea or amenorrhoea, hyperandrogenemia, hirsutism, acne, androgen alopecia and polycystic ovaries as the key diagnostic feathers. The study was undertaken to investigate the possible protective and ameliorating effects of GABA in Letrozole induced PCOS model in rats by targeting insulin resistance.

Methods

PCOs in Adult female rat was induced by the daily gastric administration of letrozole (1 mg/kg/day) in CMC (0.5%) for 36 days. Rats were given metformin (2 mg/kg), GABA (100 mg/kg/day) and GABA (500 mg/kg/day) along with letrozole. One group severed as vehicle control. On the 37 day, the animals were euthanized, and anthropometrical, biochemical (glucose, insulin, lipids, testosterone, Estradiol, Progesterone, oral glucose tolerance test, total protein content in ovary, cholesterol level, triglyceride, HDL, LDL), Antioxidants (CAT, POD, GSR, ROS, GSH, TBARS), and histopathological evaluation of ovaries were carried out. Daily colpocytological examination was also carried out until the termination.

Results

Both the doses of GABA significantly reduced body weight, body mass index and testosterone. While the levels of CAT, SOD, POD and Estradiol (E₂) were significantly increased in the both doses of GABA. A favourable lipid profile, normal glucose tolerance, and decreased in the percentage of estrus smears were observed. Histopathological examination of ovary revealed a decreased in the number of cystic follicles, and decreased in the adipocytes respectively. The effects observed with GABA were comparable to that with metformin.

Conclusion

The results suggest that GABA treatment has shown protective effect in PCOs and provide beneficial effect either by reducing insulin resistance or by inducing antioxidant defence mechanisms.

Free radical and superoxide reactivity detection in semen quality assessment: past, present, and future

Oxidative stress is a well-established cause of male infertility, with reactive oxygen species (ROS) impairing sperm production, motility, membrane, and DNA integrity. Currently, most clinics do not test infertile patients for the imbalance between ROS generation and the ability of the antioxidants to scavenge them, although there is a clear need for andrology laboratories to be able to identify and/or quantify seminal oxidative stress. As such there is a clinical urgency for an inexpensive and easy-to-perform assay able to identify oxidative stress in semen. The aim of this review is to provide information on the currently available methods to assess and quantify ROS and particularly superoxide in male reproductive cells, tissues, and fluids which may have a significant clinical utility in identifying men with impaired fertility associated with oxidative stress. Through a deeper understanding of oxidative stress and its assessment options, clinical andrology labs may better assist patients to achieve increased rates of fertility and pregnancy.

Protective Effect of Royal Jelly on In Vitro Fertilization (IVF) in Male Mice Treated with Oxymetholone

Objective

This study aimed to investigate the effects of royal jelly (RJ) on catalase, total antioxidant capacity and embryo development in adult mice treated with oxymetholone (OXM).

Materials and Methods

In this exprimental study, 32 male and 96 female adult Naval Medical Research Institute (NMRI) mice (7-9 weeks of age) with a ratio of 1:3 for fertili- zation purposes were randomly divided into 4 groups as follows: i. Control group (n=8) receiving 0.1 ml/mice saline daily by gavage for 30 day, ii. RJ group (n=8) treated with RJ at a dose of 100 mg/kg daily by gavage for 30 days, iii. OXM group (n=8) receiving OXM at the dose of 5 mg/kg daily by gavage for 30 days and iv. RJ+OXM group (n=8) receiving RJ at the dose of 100 mg/kg daily by gavage concomitant with 100 mg/kg OXM adminis- tration for 30 days.

Results

Analysis revealed a significant reduction in catalase, total antioxidant, as well as embryo development in OXM group (P<0.05). However, RJ group showed a salient recovery in the all of the above mentioned parameters and embryo toxicity.

Conclusion

The results of this study indicated a partially protective effect of RJ against OXM-induced embryo toxicity.

Leukocytes and oxidative stress: dilemma for sperm function and male fertility

Spermatozoa are constantly exposed to the interphase between oxidation through high amounts of reactive oxygen species (ROS) and leukocytes, and reduction by means of scavengers and antioxidants. Considering the very special functions as being the only cells with such high polarization and exerting their functions outside the body, even in a different individual, the female genital tract, the membranes of these cells are chemically composed of an extraordinary high amount of polyunsaturated fatty acids. This in turn, renders them very susceptible to oxidative stress, which is defined as an imbalance between oxidation and reduction towards the oxidative status. As a result, ROS deriving from both leukocytes and the male germ cells themselves cause a process called 'lipid peroxidation' and other damages to the sperm cell. On the other hand, a certain limited amount of ROS is essential in order to trigger vital physiological reactions in cells, including capacitation or the acrosome reaction in sperm. The treatment of patients with antioxidants to compensate the oxidative status caused by oxidative stress is highly debated as uncontrolled antioxidative treatment might derail the system towards the reduced status, which is also unphysiological and can even induce cancer. This paradox is called the 'antioxidant paradox'. Therefore, a proper andrological diagnostic work-up, including the evaluation of ROS levels and the antioxidant capacity of the semen, has to be carried out beforehand, aimed at keeping the fine balance between oxidation and scavenging of vital amounts of ROS.

Comments on the release of the 5th edition of the WHO Laboratory Manual for the Examination and Processing of Human Semen

The authors of the World Health Organization Semen Analysis Manual are to be congratulated on producing a new edition; it is an essential tool to disseminate good practice in andrology. However, the tests described have poor prognostic power to predict a man's fertility and show little about the underlying causes of sub-fertility. This commentary urges a revival of research into the diagnosis of male fertility. It suggests that fertility should be regarded as a continuum and that the artificial binary division between fertile and infertile should be abandoned. Models to predict a sub-fertile couple's chance of conception in a year should be developed on the basis of prospective data. These models would allow for sophisticated decision making about management. The future lies in the identification of tests to detect underlying pathologies open to specific treatment. Leads such as oxidative stress, defects in the intracellular regulation and the developing field of proteomics should be explored.

Effect of ultraviolet C irradiation on human sperm motility and lipid peroxidation

PURPOSE

Ultraviolet C (UVC) irradiation of aqueous solutions is known to be a good source of reactive oxygen species (ROS). The aim of this study is to examine the effect of increasing doses of UVC irradiation, in the presence and absence of the antioxidant butylated hydroxytoluene (BHT), on human sperm motility and lipid peroxidation of its membranes.

MATERIALS AND METHODS

Human sperm samples were irradiated with UVC light (254 nm) for different periods of time. A computer-assisted semen analysis of sperm motility was carried out after UV irradiation. The percentage of motile sperm (%MOT), progressive motility, straight line velocity (VSL), curvilinear velocity (VCL) and the percentage of linearity (%LIN) were evaluated. The level of lipid peroxidation of sperm membranes was estimated by measurement of the thiobarbituric acid reactive substances (TBARS).

RESULTS

UVC irradiation of human spermatozoa produced a diminution of the sperm motility (%MOT, progressive motility, VSL, VCL, %LIN), viability and, concomitantly, an increase of the level of lipid peroxidation of the sperm membranes. The observed effects of the UVC irradiation were prevented by addition of the antioxidant BHT, indicating that the effects of UVC on the tested sperm parameters are mediated by an important rise in lipid peroxidation of the sperm membrane.

CONCLUSION

Lipid peroxidation of the human sperm plasma membrane leads to a decrease in the sperm motility (%MOT, progressive motility, VSL, VCL, %LIN) and viability. The protective effect of BHT on the UVC-irradiated sperm cells indicates the effects of ROS on sperm function.

Increased lipid peroxidation and abnormal fatty acid profiles in seminal and blood plasma of normozoospermic males from infertile couples

BACKGROUND

Reactive oxygen species (ROS) are essential for sperm function. However, excessive ROS production can impair sperm function and might be a factor contributing to male infertility.

METHODS

We investigated the levels of arachidonic acid (AA) and docosahexaenoic acid (DHA) as well as lipid peroxidation, as represented by thiobarbituric acid reactive species (TBARS), in blood and seminal plasma of 38 normozoospermic males from infertile couples (NSI-males), compared with that of 17 fertile volunteers (FV-males).

RESULTS

TBARS levels in blood and seminal plasma were higher in NSI-males than in FV-males (P < 0.0002, P < 0.0003, respectively), as were AA levels (P < 0.0003, P < 0.00004, respectively). On the contrary, the blood and seminal plasma levels of DHA were lower in NSI-males than in FV-males (P < 0.02 and P < 0.05, respectively). The AA/DHA ratios in blood and seminal plasma were higher in NSI-males than in FV-males (P < 0.003, P < 0.0007, respectively). Significant correlations between seminal and blood plasma levels of TBARS (P < 0.0001, r = 0.548), AA (P < 0.0001, r = 0.571) and DHA (P < 0.0001, r = 0.506) were found.

CONCLUSIONS

Our data provide new insight into lipid metabolism in male infertility and indicate that systemic oxidative stress resulting in increased lipid peroxidation and an altered fatty acid profile may be, at least in part, responsible for infertility even in normozoospermic males.

Male gamete survival at stake: causes and solutions

Over the years, the development of assisted reproductive technology to bypass male factor infertility has improved drastically. Considered one of the most perplexing disorders in the reproductive field, male factor infertility is prevalent and may be on the rise. Unfortunately, its aetiology remains elusive. One of the main reasons lies in the complex machinery and structure of the hydrodynamic sperm cell. Its polyunsaturated fatty acid cell membrane, the protamines in its genetic material and the absence of antioxidants in its cytoplasm ensure that the spermatozoon is highly susceptible to environmental effects. The spermatozoon's genesis, storage, and transport through the male reproductive tract are also susceptible, genetically and pathologically, to environmental effects. This review aims to include all the possible causes of disruption to this unique cell and their probable solutions, in the hope of clearing up the ambiguity that surrounds male factor infertility.

Long-time exposure of mouse embryos to the sperm produces high levels of reactive oxygen species in culture medium and relates to poor embryo development

Small amounts of reactive oxygen species (ROS), metabolites of oxygen, are necessary for sperm-fertilizing capability. However, in excessive levels, their role in infertility has been extensively studied. The conventional in vitro fertilization (IVF) method employs a prolonged co-incubation of gametes for 16-18 h to reach fertilization. However, it has been shown that this long period might create high levels of ROS. We aimed at finding out whether ROS increases in vitro during prolonged incubation with fertilized oocytes and whether high level of ROS relates to poor embryo development. To confirm if levels of ROS relate to length of time, we measured the ROS levels in fertilization medium (FM), which contained mouse embryos exposed to spermatozoa. To evaluate the contribution of sperm in production of ROS, we measured the ROS in the medium with only sperm. The measurements were performed by chemiluminescence assay using luminol as a probe after 4 and 18 h of incubation separately. The ROS levels were significantly increased after 18 h as compared with 4 h (p < 0.0001). Moreover, ROS in the medium with only sperm was also increased after 18 h (p < 0.0001), demonstrating that they were generated either by spermatozoa or as a result of possible reaction of sperm with medium during prolonged incubation. In addition, we compared embryo development after 2, 4, 6, 8, 10, 12 and 18 h of incubation. The number of degenerated embryos exposed to sperm for 12 and 18 h was significantly higher than those exposed for 4 or 6 h (p < 0.01). These results demonstrate that ROS concentrations appear to be related to the length of incubation time, and their excessive levels have a negative effect on embryo development. We suggest reducing incubation time to at least 4 h.

Cut-off value of reactive oxygen species for predicting semen quality and fertilization outcome

Though the role of reactive oxygen species (ROS) in male infertility is widely investigated worldwide, there is a lack of adequate information on the cut-off value of ROS beyond which ART outcome may be adversely affected. The objective of the present study is to establish an upper level of ROS in semen samples which can be considered as a potential marker of good semen quality. Semen ejaculates were randomly collected from 338 male partners of infertile couples. The upper critical limit (UCL) of ROS was calculated from the control chart of normozoospermic patients and found to be 0.75x10(6) counted photons per minute (cpm)/10 million cells. This was further validated by estimating ROS in 17 proven fertile men and 38 patients undergoing intra cytoplasmic sperm injection (ICSI). As expected, all abnormal semen samples exhibited higher ROS as compared to nomozoospermic and proven fertile samples. All semen samples from proven fertile volunteers were found to be <0.075x10(6) cpm/10 million cells. On the basis of the calculated UCL, ICSI patients were divided into two groups: Group I (<UCL) and Group II (>UCL). The semen parameters, fertilization rate and pregnancy outcome were found to be significantly affected in Group II. Significant difference in live birth-rates was observed between Group I (47.6%) and Group II (17.6%) while no live-birth was recorded for ROS level >0.1x10(6) cpm/10 million cells. It is concluded that the upper cut-off value of normal semen samples that correlates with good semen quality is, therefore, in the order of 0.075-0.1x10(6) cpm/10 million cells. In addition to the WHO [1999] semen analysis, this range is expected to assist andrologists and clinicians in predicting semen quality and fertilization outcome in patients with male factor infertility undergoing ICSI.

Oxidative stress and male infertility--a clinical perspective

Oxidative stress occurs when the production of potentially destructive reactive oxygen species (ROS) exceeds the bodies own natural antioxidant defenses, resulting in cellular damage. Oxidative stress is a common pathology seen in approximately half of all infertile men. ROS, defined as including oxygen ions, free radicals and peroxides are generated by sperm and seminal leukocytes within semen and produce infertility by two key mechanisms. First, they damage the sperm membrane, decreasing sperm motility and its ability to fuse with the oocyte. Second, ROS can alter the sperm DNA, resulting in the passage of defective paternal DNA on to the conceptus. This review will provide an overview of oxidative biochemistry related to sperm health and will identify which men are most at risk of oxidative infertility. Finally, the review will outline methods available for diagnosing oxidative stress and the various treatments available.

Counting sperm does not add up any more: time for a new equation?

Although sperm dysfunction is the single most common cause of infertility, we have poor methods of diagnosis and surprisingly no effective treatment (excluding assisted reproductive technology). In this review, we challenge the usefulness of a basic semen analysis and argue that a new paradigm is required immediately. We discuss the use of at-home screening to potentially improve the diagnosis of the male and to streamline the management of the sub-fertile couple. Additionally, we outline the recent progress in the field, for example, in proteomics, which will allow the development of new biomarkers of sperm function. This new knowledge will transform our understanding of the spermatozoon as a machine and is likely to lead to non-ART treatments for men with sperm dysfunction.

Analysis of lipid peroxidation in human spermatozoa using BODIPY C11

Lipid peroxidation is known to be a major factor in the aetiology of defective sperm function. Although biochemical assays for this process exist, they are relatively insensitive and require large numbers of spermatozoa; a condition that cannot be met with many infertility specimens. Recently, a new approach for monitoring peroxidative damage has been introduced, involving the probe BODIPY (581/591) C(11), which readily incorporates into cells and undergoes a spectral emission shift when attacked by reactive oxygen metabolites. We have examined the applicability of this probe as an indicator of oxidative stress in human sperm populations using flow cytometry as an end point. The measurement of peroxidation with BODIPY C(11) demonstrated significant dependence on the presence of a ferrous ion promoter (P < 0.001), which was significantly enhanced in sperm recovered from low-density Percoll fractions (P < 0.05) and was particularly damaging to the sperm midpiece. Iron-induced radical formation was suppressed by ascorbate in a dose-dependent manner (P < 0.001) and could only be promoted by Fe(II) and Cu(II); nickel, zinc and Fe(III) were ineffective. The Fe(II)-promoted BODIPY C(11) signal was significantly correlated with the measurement of reactive oxygen species generation with dihydroethidium. We conclude that BODIPY C(11) is an extremely useful probe for indexing peroxidative damage in human spermatozoa.

Antimicrobial drug ornidazole inhibits hamster sperm capacitation, in vitro

To be fertilization competent, spermatozoa undergo a series of changes in the female reproductive tract collectively referred to as capacitation. In an attempt to understand, if ornidazole, a known anti-fertility drug, adversely affects sperm functions by targeting capacitation, we designed experiments to study the influence of this drug on hyperactivation (HA), capacitation-associated protein tyrosine phosphorylation (pY) and the acrosome reaction (AR). Addition of ornidazole at 0 h, inhibited the onset of HA and total pY in a dose dependent manner. However, when ornidazole was added at 3.5h, severe effects were still seen on HA and pY of high molecular weight proteins but, pY of lower M(r) proteins (50-56 kDa) was affected only marginally. Further, lower doses of ornidazole (5 and 10 mM) had greater inhibitory effect when added at 0 h, while addition of ornidazole at 3.5 h required higher doses of ornidazole (25 mM) to cause significant inhibition of acrosome reaction. Collectively, through in vitro studies, we demonstrate that ornidazole affects the onset and progression of hamster sperm hyperactivation, capacitation associated protein tyrosine phosphorylation and acrosome reaction, and the severity depends on the dose (5, 10 or 25 mM) and the time of addition (0 or 3.5 h) of the drug to the spermatozoa.

Predictive value of the hemizona assay for pregnancy outcome in patients undergoing controlled ovarian hyperstimulation with intrauterine insemination

OBJECTIVE

The hemizona assay (HZA) is an established functional test that examines in vitro sperm-zona pellucida binding capacity with high predictive power for fertilization outcome in IVF. The objective of this study was to evaluate the value of the HZA as a predictor of pregnancy in patients undergoing controlled ovarian hyperstimulation (COH) and intrauterine insemination (IUI).

DESIGN

Prospective clinical study.

SETTING

Academic center.

PATIENT(S)

Eighty-two couples with unexplained or male factor infertility that underwent 313 IUI cycles.

INTERVENTION(S)

Basic semen analysis and HZA were performed within three months of starting COH/IUI therapy.

MAIN OUTCOME MEASURE(S)

Hemizona index (HZI) and clinical pregnancy.

RESULT(S)

Overall, patients with an HZI of <30 had a significantly lower pregnancy rate compared to patients with an HZI of > or =30 (11.1% vs. 40.6%, respectively; P<.05; relative risk for failure to conceive: 1.5 (confidence interval 1.2-1.9)). In all patients combined, and in the range of HZI 0-60, the duration of infertility (P=.000) and the HZI (P=.004) were significant determinants of conception (receiver operating characteristics (ROC) analysis). In couples with male infertility, the average path velocity and HZI were significant predictors of conception (P=.001 and P=.005, respectively, ROC analysis). The negative and positive predictive values of the HZA for pregnancy were 93% and 69%, respectively. Logistic regression analysis provided models of HZI (P=.021) and duration of infertility (P=.037) with highest predictability of conception in male factor and unexplained infertility groups, respectively.

CONCLUSION(S)

The HZA predicted pregnancy in the IUI setting with high sensitivity and negative predictive value in couples with male infertility. Results of this sperm function test are useful in counseling couples before allocating them into COH/IUI therapy.