Antioxidant therapy in male infertility: fact or fiction?

Grape Seed Proanthocyanidins Improve the Quality of Fresh and Cryopreserved Semen in Bulls

Oxidative stress leads to a decrease in semen quality during semen cryopreservation and fresh semen production. Grape seed proanthocyanidins (GSPs) are endowed with well-recognized antioxidant, anti-inflammatory, anti-cancer, and anti-aging activities. Therefore, the objective of this experiment was to explore the effects of GSPs on the quality of fresh and cryopreserved semen to provide a basis for GSPs as a new dietary additive and semen diluent additive for males' reproduction. Fresh semen from three healthy bulls aged 3 to 5 years old were gathered and mixed with semen diluents dissolved with 0 µg/mL, 30 µg/mL, 40 µg/mL, 50 µg/mL, and 60 µg/mL GSPs respectively. The motility, physiological structures (acrosome integrity, membrane integrity, mitochondrial activity), and antioxidant capacity of frozen-thawed sperm were measured after storage in liquid nitrogen for 7 days (d). Bulls were fed with 20 mg/kg body weight (BW) GSPs in their diet for 60 days; the weight of the bull is about 600 kg. Then, the reproductive performance and antioxidant indexes of bulls were measured before and after feeding. The results demonstrated that GSPs supplementation significantly increased sperm motility, physiological structures, GSH-Px, and CAT enzyme activities and significantly decreased MDA content in sperm during semen cryopreservation. The optimal concentration of GSPs was 40 µg/mL (p < 0.05). After 20 mg/kg (body weight) GSP supplementation, sperm motility was significantly heightened (p < 0.05), the sperm deformity rate was significantly reduced (p < 0.05), and antioxidant enzyme activities (such as SOD, CAT, and GSH-Px) were significantly enhanced (p < 0.05), and the production of MDA was significantly suppressed (p < 0.05) in serum compared with that before feeding. In conclusion, these results reveal that a certain concentration of GSPs has a good protective effect on sperm damage caused by semen cryopreservation and the reproductive performance reduction caused by stress in bulls, which may be attributed to the antioxidant function of GSPs. In summary, GSPs are a useful cryoprotective adjuvant and dietary additive for bull sperm quality.

Evaluation of Post-Thaw Swim-Up Selection Combined With Glutathione Addition for Improvement of Sperm Chromatin Maturity in Normozoospermic Samples

BACKGROUND

Cryopreservation of human semen alters the spermatozoal structure, resulting in a reduction in sperm function parameters. Various antioxidants may be able to slow or prevent this type of injury. Glutathione (GSH) has numerous antioxidant properties; supplementing the semen with GSH before freezing may assist in the restoration of post-thaw sperm functionality.

OBJECTIVE

 To investigate the effect of adding 5mM of glutathione before freezing on human sperm cryosurvival.

MATERIALS AND METHODS

Semen samples were collected from 30 patients (22 normozoospermic and 8 asthenozoospermic) after 3-5 days of sexual abstinence. Following liquefaction, macro- and microscopic examinations were performed. The samples were then divided into two equal aliquots: the first aliquot received 5 mM of glutathione before freezing, and the second aliquot was considered the control (without glutathione). The samples were frozen using the rapid cryopreservation method and then preserved for 7-10 days in a liquid nitrogen tank before being thawed. Thawed samples from each group were examined microscopically according to the WHO 2010 guidelines. Aniline blue was used to assess the maturity of the DNA. Then, the direct-swim-up technique was applied to thawed samples from both groups to select the best sperm quality.

RESULTS

The cryopreservation process negatively impacts all sperm characteristics in both groups. Sperm DNA integrity decreased. Glutathione addition before freezing decreased sperm chromatin immaturity (SCI) percent compared to the control (22.98 ± 0.83, 20.79 ± 0.56). The post-thaw performance of the swim-up technique resulted in a select sperm population with high progressive motility (p = 0.04) and an improvement in DNA integrity in the treated group versus the control group after thawing.

CONCLUSION

The DNA integrity in normozoospermic samples was improved by adding 5 mM glutathione before freezing. Performing the swim-up technique after thawing had no effect on sperm quality in asthenozoospermic patients.

Molecular Markers: A New Paradigm in the Prediction of Sperm Freezability

For decades now, sperm cryopreservation has been a pillar of assisted reproduction in animals as well as humans. Nevertheless, the success of cryopreservation varies across species, seasons, and latitudes and even within the same individual. With the dawn of progressive analytical techniques in the field of genomics, proteomics, and metabolomics, new options for a more accurate semen quality assessment have become available. This review summarizes currently available information on specific molecular characteristics of spermatozoa that could predict their cryotolerance before the freezing process. Understanding the changes in sperm biology as a result of their exposure to low temperatures may contribute to the development and implementation of appropriate measures to assure high post-thaw sperm quality. Furthermore, an early prediction of cryotolerance or cryosensitivity may lead to the establishment of customized protocols interconnecting adequate sperm processing procedures, freezing techniques, and cryosupplements that are most feasible for the individual needs of the ejaculate.

OXIDATIVE STRESS AND REPRODUCTIVE FUNCTION: The protection of mammalian spermatozoa against oxidative stress

In brief

This review focuses on the enzymatic antioxidant mechanisms to fight oxidative stress by spermatozoa, highlighting the differences among mammalian species. We discuss recent evidence about players that promote and fight oxidative stress and the need for novel strategies to diagnose and treat cases of male infertility associated with oxidative damage of the spermatozoon.

Abstract

The spermatozoon is very sensitive to high reactive oxygen species (ROS) levels due to its limited antioxidant system. A consortium of antioxidant enzymes, including superoxide dismutase (SOD), glutathione peroxidases (GPXs), peroxiredoxins (PRDXs), thioredoxins, and glutathione-S-transferases, is necessary to produce healthy spermatozoa and to maintain sperm quality to ensure motility, capacitation, and DNA integrity. A delicate balance between ROS production and antioxidant enzymes is needed to ensure ROS-dependent sperm capacitation. GPX4 is an essential component of the mitochondrial sheath in mammalian spermatozoa, and GPX5 is a crucial antioxidant defence in the mouse epididymis to protect the sperm genome during the maturation of the spermatozoon. The mitochondrial superoxide (O2·–) production is controlled by SOD2, and the hydrogen peroxide (H2O2) generated by SOD2 activity and peroxynitrite (ONOO–) are scavenged mainly by PRDXs in human spermatozoa. PRDXs regulate the redox signalling necessary for sperm motility and capacitation, particularly by PRDX6. This enzyme is the first line of defence against oxidative stress to prevent lipid peroxidation and DNA oxidation by scavenging H2O2 and ONOO– through its peroxidase activity and repairing oxidized membranes by its calcium-independent phospholipase A2 activity. The success of antioxidant therapy in treating infertility resides in the proper diagnosis of the presence of oxidative stress and which type of ROS are produced. Thus, more research on the molecular mechanisms affected by oxidative stress, the development of novel diagnostic tools to identify infertile patients with oxidative stress, and randomized controlled trials are of paramount importance to generate personalized antioxidant therapy to restore male fertility.

Effect of Different Concentrations of Melatonin on Ram Epididymal Spermatozoa Recovered Post-mortem under Oxidative Stress Conditions and Storage at 4 °C

The current study examines the protective effects of different melatonin concentrations on fresh ram epididymis spermatozoa after post-mortem recovery under normal and oxidative stress conditions and during liquid preservation (4^o C) at different times (24, 48, and 72h). The testes were obtained from a local slaughterhouse during the breeding season. Spermatozoa were isolated from cauda epididymidis. In experiment 1, the effects of adding different concentrations of melatonin (0, 15, 60, and 240 μg/mL) under normal and oxidative stress conditions were evaluated. Fifty μM of hydrogen peroxide was used to induce oxidative stress. Also, in experiment 2, the spermatozoa samples were chilled to 4^o C and stored for 72 h. Sperm total motility, viability, membrane, DNA integrity, and morphological abnormality were evaluated at 0, 24, 48, and 72 h after cooling storage. In experiment 1, melatonin treatment preserved viability increased TAC and SOD activities, and reduced MDA levels compared to control. Also, melatonin reduced the harmful effects of H2O2 under induced oxidative stress. In experiment 2, Melatonin at concentrations of 15 and 60 g/mL greatly increased sperm viability after 3 days of cold storage. Furthermore, it could have a significant protective effect on the motility of cooled sperm. Melatonin supplementation preserved higher sperm membrane integrity at concentrations of 15 and 60μg/mL, DNA integrity at a concentration of 15μg/mL, and abnormality at a concentration of 60μg/mL after 3 days of storage. The results suggest that melatonin can be used to reduce the adverse effects of induced oxidative stress in spermatozoa. Furthermore, ram epididymal spermatozoa could be stored at 4 °C for 72 h when treated with melatonin.

Sperm DNA fragmentation in reproductive medicine: A review

Approximately 15% of the world's couples suffer from infertility during their reproductive period of which the male factor is responsible for 50% of cases. Male factor infertility is multifactorial in origin, and sperm DNA fragmentation (SDF) has also been linked to male infertility including idiopathic male infertility. Some degree of controlled DNA nicking is essential for adequate DNA compaction, but excessive SDF is usually associated with reduced male fertility potential, reduced fertilisation, poor embryo quality, recurrent pregnancy loss and poor assisted reproductive techniques (ARTs) outcomes. Although semen analysis remains the gold standard for diagnosis of male factor infertility worldwide, its limitations motivated the search and the development of complementary tests of sperm function and integrity. SDF assay is an emerging diagnostic tool in infertile men, and several indications for SDF testing in infertile couples have also been proposed. The use of SDF in routine male infertility assessment is, however, still controversial. Furthermore, both direct and indirect SDF tests are now available. Hence, the present review was conducted to summarise the recent evidence of SDF, underlying mechanisms, clinical indications, diagnostic tests, as well as the role of SDF in male factor infertility, pregnancy and ART outcomes.

Protective Effect of Chlorogenic Acid on Human Sperm: In Vitro Studies and Frozen-Thawed Protocol

The study evaluated the chlorogenic acid (CGA) antioxidant potential on oxidative stress (OS) induced in vitro in human spermatozoa and during cryopreservation procedure. Swim-up selected spermatozoa were treated with 100 µM CGA, 100 µM H₂O₂ to induce lipid peroxidation (LPO), and with both compounds and the effects on mitochondrial membrane potential (MMP) by JC-1, DNA integrity by acridine orange (AO), and sperm ultrastructure by transmission electron microscopy (TEM), were evaluated. CGA antioxidant activity was assessed by measuring malondialdehyde (MDA) and F₂-isoprostanes (F₂-IsoPs) in the media. The CGA protective activity and the immunolocalization of Phospho-AMPKα (Thr172) were explored in frozen-thawed sperm. CGA was not toxic for sperm motility, DNA integrity and MMP. The increase in MDA (p < 0.05) and F₂-IsoPs (p < 0.001), DNA damage (p < 0.01) and low MMP (p < 0.01) levels after H₂O₂ treatment were reduced in presence of CGA as well as the percentage of broken plasma membranes (p < 0.01) and altered acrosomes (p < 0.01) detected by TEM. Treated frozen-thawed spermatozoa showed increased sperm motility (p < 0.01), DNA integrity (p < 0.01), MMP (p < 0.01), reduced MDA (p < 0.01) and increased sperm percentage with Phospho-AMPKα labelling in the head (p < 0.001). CGA can be used to supplement culture media during semen handling and cryopreservation where OS is exacerbated.

Cryoprotective Effect of Tretinoin-Loaded Solid Lipid-Core Nanocapsules During Fresh and Freeze/Thaw Media on NMRI Mouse Sperm Parameters, DNA Damage, and Reactive Oxygen Species Production

Due to the induced oxidative stress that exists in sperm freezing/thawing procedures and handling media, the use of exogenous antioxidant agents seems necessary. Drug delivery by nanocarriers has been designed to overcome the limitations of antioxidants, such as high-dose toxicity and short biological half-life. In this study, we tried to investigate the effects of tretinoin-loaded solid lipid core nanocapsules (TTN-SLN) added to freezing/thawing and handling media (in three experimental groups) on sperm motility (total/progressive), viability, DNA fragmentation, and extracellular reactive oxygen species (ROS) levels. Sperm samples from at least 30 adult male NMRI mice were evaluated in this study. The results of experiments 1 and 2 showed that the addition of 0.5 μM TTN-SLN in freezing and thawing medium significantly increased sperm viability and total/progressive motility and decreased DNA fragmentation and extracellular ROS levels (p < 0.05). Adding 0.25 and 0.5 μM of TTN-SLN to the handling medium (experiment 3), increased sperm parameters and decreased DNA fragmentation and extracellular ROS levels significantly (p < 0.05) compared with the control group. Briefly, our results indicate that SLN can deliver the lowest concentrations of tretinoin in a controlled release mechanism into the intracellular space of sperm. Also, high-dose TTN-SLN is safe during freezing/thawing and handling processes of mouse sperm.

Neurological Alterations and Testicular Damages in Aging Induced by D-Galactose and Neuro and Testicular Protective Effects of Combinations of Chitosan Nanoparticles, Resveratrol and Quercetin in Male Mice

Aging is a neurological disease that is afforded by incidence of oxidative stress. Chitosan has received global interests due to its wide medical uses. Quercetin (Q) is a bioflavonoid and widely distributed in vegetables and fruits. Resveratrol is considered as a potent antioxidant and is a component of a wide range of foods. The using of either chitosan nanopartciles (CH-NPs), querectin (Q), and resveratrol (RV) to reduce the oxidative stress and biochemical alterations on brain and testicular tissues induced by D-galactose (DG) (100 mg/Kg) were the aim of the present study. This study investigated the probable protective effects of CH-NPs in two doses (140,280 mg/Kg), Q (20 mg/Kg) and RV (20 mg/Kg), against DG induced aging and neurological alterations. Brain antioxidant capacity as malonaldehyde (MDA), catalase (CAT), and glutathione reductase (GRx), as well as histopathological damages of the brain and testicular tissues were measured. The DG treated group had significantly elevated the oxidative stress markers by 96% and 91.4% in brain and testicular tissues respectively and lower significantly the antioxidant enzyme activities of both brain and testicular tissues than those of the control group by 86.95%, 69.27%, 83.07%, and 69.43%. Groups of DG that treated with a combination of CH-NPs in two doses, Q and RV, the levels of oxidative stress marker declined significantly by 68.70%, 76.64% in brain tissues and by 74.07% and 76.61% in testicular tissues, and the enzymatic antioxidants increased significantly by 75.55%, 79.24%, 62.32%, and 61.97% as compared to the DG group. The present results indicate that CH-NPs, Q, and RV have protective effects against DG-induced brain and testis tissue damage at the biochemical and histopathological levels. Mechanisms of this protective effect of used compounds against neurological and testicular toxicity may be due to the enhanced brain and testis antioxidant capacities.

Antioxidant treatment of increased sperm DNA fragmentation: Complex combinations are not more successful

OBJECTIVE

Oral antioxidant supplementation is part of the treatment of infertility associated with oxidative stress-related sperm damage. It is possible to assume that the combined use of antioxidants will be better than single agent use. The purpose of this study was to compare the effectiveness of different antioxidant combinations in infertile men with increased sperm DNA fragmentation.

MATERIALS AND METHODS

We retrospectively reviewed the records of 637 patients who underwent antioxidant support therapy for increased sperm DNA damage between 2014 and 2019. Patients with DNA damage of 30% or more were included study.

RESULT

A total of 163 patients with follow-up data and who fulfilled the study criteria were included in the study. There were four different treatment groups. No statistically significant differences were found between the groups. After 3 months of antioxidant treatment, there was a statistically significant decrease in sperm DNA damage in all treatment groups. However, there was no statistically significant difference between the treatment groups.

CONCLUSIONS

The complexity of the antioxidant combination may not contribute to the success of the treatment or may cause possible side effects, increase the cost of treatment and decrease patient compliance.

Cryoprotective effect of sericin supplementation in freezing and thawing media on the outcome of cryopreservation in human sperm

The destructive effects of sperm cryopreservation result in decreased sperm parameters and their fertilizing ability. Antioxidants supplementation can potentially improve cryopreservation outcomes. In this study, we tried to investigate the effects of sericin supplementation in freezing and thawing media on frozen-thawed human sperm motility, morphology, viability, and DNA fragmentation. In experiment 1, semen samples were collected from 30 healthy fertile men and were cryopreserved in the presence of freezing medium supplemented with different concentrations of sericin (0, 0.5, 1, 2.5, and 5%). The results showed that the addition of 2.5 and 5% sericin in freezing medium significantly increased sperm viability and total motility (A + B) and decreased DNA fragmentation (P < 0.05). In experiment 2, semen samples were collected from 21 fertile men and were cryopreserved in freezing medium without any supplementation for 48 h. Then, the samples were thawed in medium supplemented with different concentrations of sericin (0, 0.5, 1, 2.5, and 5%). The addition of 5% sericin to thawing medium increased the total motility, viability, and decreased DNA fragmentation compared with those in thaws without sericin. In nutshell, the results clearly indicate the feasibility of sericin as an cryoprotective supplement for freezing media in human spermatozoa.

Dietary supplements in the management of varicocele-induced infertility: A review of potential mechanisms

Varicocele is a main cause of lower production of spermatozoon and infertility with multiple pathophysiological mechanisms. In the past decades, the use of dietary supplements has significantly increased due to both the modern lifestyle and the food shortages of the industrialised countries. The purpose of this review paper is to collect scientific evidences from basic and clinical studies which support the use of dietary supplements to define the clinical framework for patients with varicocele. In the present review, we used keywords such as dietary supplements, varicocele, male infertility, oxidative stress, DNA fragmentation, sperm parameters to find the proper articles. The standard search biomedical engines were used for seeking the papers. The use of dietary supplements such as minerals, vitamins and antioxidants has an essential role in the prevention and treatment of varicocele by increasing the levels of antioxidant enzymes (e.g. peroxidase, superoxide dismutase and catalase) and decreasing the levels of inflammatory markers (e.g. tumour necrosis factor-α, interleukin-6 and interleukin-1) in testis. According to the results, the dietary supplements may alleviate the spermatogenesis in varicocele patients through different mechanisms such as suppression of stress oxidative and inflammation in testicular tissue.

Alpha-lipoic acid improves sperm motility in infertile men after varicocelectomy: a triple-blind randomized controlled trial

RESEARCH QUESTION

Does supplementation with alpha-lipoic acid (ALA) enhance sperm parameters and/or the status of sperm lipid peroxidation and DNA fragmentation in men who have undergone microsurgical repair of a varicocele?

DESIGN

Individuals with a varicocele who had undergone varicocelectomy were divided into two groups receiving either 600 mg of ALA or an identical placebo for 80 days. Semen samples obtained from the participants before surgery and after completion of the course of medication were analysed and compared. Participants, clinicians and data analysts were blinded to the randomization sequence.

RESULTS

In the ALA group, total motility (P = 0.01) and progressive motility (P = 0.002) of the spermatozoa were significantly higher compared with the placebo group after surgery. Sperm lipid peroxidation and DNA damage (assessed by sperm chromatin structure assay) showed significant decreases in both the ALA and placebo groups (P ≤ 0.02) after treatment.

CONCLUSIONS

An 80-day course of ALA medication after surgical repair improves total motility and progressive motility of the spermatozoa in individuals with a varicocele.

TUNEL assay-Standardized method for testing sperm DNA fragmentation

Sperm DNA integrity is important for normal functions such as fertilization, implantation, pregnancy and fetal development. Sperm DNA fragmentation (SDF) is more common in infertile men and may be responsible for poor reproductive function. Although there are a number of tests available to measure SDF, the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-nick end labelling TUNEL) assay using flow cytometry is becoming more popular to measure the sperm DNA fragmentation. It is a direct test that measures both single- and double- DNA strand breaks. In this review, we describe the protocol, quality control and measurement of sperm DNA fragmentation using a benchtop flow cytometer. We also briefly discuss the factors that can affect the results, challenges and clinical implications of TUNEL in assessing male infertility.

A Novel Combination of γ-Tocopherol-Rich Mixture of Tocopherols and Ascorbic Acid Restores Fertility in Cases of Tyrosine Nitration-Associated Male Infertility in Mice

Infertility is an important health problem that affects up to 16% of couples worldwide. Male infertility is responsible for 50% of the cases. Currently, a physical examination, hormone profiling and the evaluation of two consecutive semen samples (to determine the sperm concentration, motility, morphology and, in very few cases, sperm DNA integrity) are the sole tools that physicians have to evaluate infertility in men. Antioxidant therapy is often used to improve sperm quality and function in infertile men. However, there are controversial results regarding the efficacy of these treatments. Prdx6^-/- male mice are subfertile, displaying significant oxidative damage in the lipids, proteins and DNA of their spermatozoa. Here, we used Prdx6^-/- male mice to test whether a novel combination of tocopherols that contained 60% γ-tocopherol and ascorbic acid could restore their fertility. These mice were fed with the supplemented (Vit. Mix) or control diets. To assess sperm quality, we determined the motility, levels of lipid peroxidation, DNA oxidation and tyrosine nitration in the spermatozoa. The number of pups sired by the Prdx6^-/- mice fed with the Vit. Mix diet was higher than that sired by the males fed with the control diet, and the pups' mortality was lower. The sperm quality was improved in the males fed with the supplemented diet. We concluded that treatment with a supplement composed of tocopherols and rich in γ-tocopherol and ascorbic acid is effective in restoring fertility in cases where oxidative stress and high levels of tyrosine nitration are associated with male infertility.

Reactive Oxygen Species and Male Fertility

Human infertility affects ~15% of couples worldwide, and it is now recognized that in half of these cases, the causes of infertility can be traced to men[...].

Efficacy of Antioxidant Supplementation on Conventional and Advanced Sperm Function Tests in Patients with Idiopathic Male Infertility

Antioxidants are used in the empirical treatment of infertile men. The aim of this study was to evaluate the effects of antioxidant therapy on conventional semen parameters and advanced sperm function tests in men seeking fertility treatment. A total of 148 infertile men of unknown etiology were divided into idiopathic (n = 119) and unexplained male infertility (UMI; n = 29). All participants were treated with the antioxidant supplement 'FH PRO for Men' for a period of three months. Compared with pretreatment results, there was a significant improvement in conventional semen parameters including sperm concentration, total and progressive motility and normal morphology, and seminal oxidation reduction potential (ORP), and sperm DNA fragmentation (SDF) in idiopathic infertile men. The changes were more prominent in idiopathic infertile men positive for ORP and SDF. UMI patients showed an improvement in progressive motility, ORP, and SDF after antioxidant treatment. Statistical analysis revealed that the efficacy of FH PRO for Men was significant in idiopathic male infertility compared with UMI. Treatment of idiopathic male infertility patients with the FH PRO for Men antioxidant regimen for three months resulted in a significant improvement in conventional semen parameters and sperm function. Therefore, FH PRO for Men offers promise for the medical treatment of idiopathic male infertility.

Does Coenzyme Q10 Exert Antioxidant Effect on Frozen Equine Sperm?

During semen cryopreservation, the sensitivity of equine sperm to oxidative stress is increased by the eliminated seminal plasma. Thus, antioxidant addition to the semen extender can be helpful to the sperm survival after freezing and thawing. This work aimed to test whether coenzyme Q10 (CoQ10) added in different concentrations to the INRA 82 freezing extender has antioxidant function on equine sperm to improve its fertilizing ability. Semen samples from five stallions were frozen with the extenders: (T1) INRA 82, control, (T2) T1+ 5 μM CoQ10, (T3) T1+ 25 μM CoQ10, and (T4) T1+ 50 μM CoQ10. After sample thawing, sperm motility and kinetics characteristics were evaluated using a computer-assisted sperm analysis and sperm membrane functionality and integrity were evaluated with a hypo-osmotic swelling test and an epifluorescence microscopy, respectively. The nitrite (NO₂^-) and hydrogen peroxide (H₂O₂) concentrations of the semen samples were measured with spectrophotometry. There was no difference on the sperm characteristics among all treatments (P > .05). However, the 25 μM CoQ10 (T3) decreased NO₂^- concentration (6.7 ± 2.2 μM/μg protein) compared with the treatments T1, T2, and T4 (64.3 ± 3.7, 59.4 ± 5.3, 45.1 ± 8.6 μM/μg protein), respectively, as well H₂O₂ concentration (1.8 ± 0.3 μM/μg protein) compared with the control (4.6 ± 0.4 μM/μg protein) and 5 μM CoQ10 treatments (4.8 ± 0.2 μM/μg protein, P < .05). In conclusion, 25 μM CoQ10 plays a significant role as antioxidant to the frozen equine sperm, decreasing NO₂^- and H₂O₂ concentrations. Thus, its addition to the INRA 82 freezing extender may be beneficial to the fertilizing ability of equine semen.

Antioxidant Effect of the Castanea sativa Mill. Leaf Extract on Oxidative Stress Induced upon Human Spermatozoa

This study was aimed at evaluating in vitro the effects of a 75% v/v ethanolic extract of leaves of Castanea sativa Mill. (var. Bastarda Rossa, Mount Amiata, Tuscany, Italy) on ejaculated human sperm. Total polyphenols and total flavonoids contained in the extract were determined by a colorimetric assay and HPLC-DAD. The DPPH test and electrochemistry were utilized to study the antioxidant activity of the extract. Swim-up-selected sperm from 8 healthy men were treated with the C. sativa leaf extract at different dilutions (1 : 100, 1 : 200, and 1 : 500), and sperm motility was assessed following the WHO guidelines. Swim-up-selected spermatozoa were incubated with 100 μM H₂O₂ to induce lipid peroxidation (LPO) and with H₂O₂ and the leaf extract (1 : 100, 1 : 200, and 1 : 500) to test the antioxidant activity of the extract. The levels of LPO were determined by measuring malondialdehyde (MDA) concentrations. The treated samples were also analyzed by transmission electron microscopy (TEM) for ultrastructural evaluation. The chemical analysis showed that one-third ca. of the polyphenols in the C. sativa extract were made up of flavonoids, with hyperoside present in high concentration. A good antioxidant activity was demonstrated by both the DPPH test and electrochemical analysis. The C. sativa leaf extract did not decrease sperm motility at all tested dilutions. Treatment with H₂O₂ alone caused a significant increment in MDA levels (P = 0.006993), while the treatment with H₂O₂ plus C. sativa extract diluted to 1 : 100 and 1 : 200 significantly reduced MDA levels (P = 0.01476 and P = 0.01571, respectively), with respect to H₂O₂ alone. TEM analysis confirmed the protective effect of the extract on damage induced by LPO, in particular that occurring at the plasma membrane level. The C. sativa leaf extract could be used in human and farm animal protocols for gamete handling, such as techniques of assisted reproduction and cryopreservation of semen, all conditions in which oxidative stress is exacerbated.

Residual effect after salmon oil supplementation on semen quality and serum levels of testosterone in dogs

The objective of present study was to evaluate the effects of oral supplementation of salmon oil on seminal parameters and testosterone serum levels in dogs, following also the residual effects for 60 days after treatment. Nine healthy male dogs with proven fertility, weighing between 10 and 36 kg, ageing from 2 to 11 years, of different breeds, fed diets supplemented with salmon oil at the manufacturer's recommended dosage. The parameters measured were sperm volume, motility, vigour, normal morphology and concentration, live/dead ratio, membrane viability by means of HOST test and serum testosterone levels. Evaluations occurred at baseline (D0), after 90 days of supplementation (D90) and at the end of the experiment, 60 days after supplementation cessation (D150). Results (mean ± SD) obtained at time D0, D90 and D150 were as follows: motility of 76.66% ± 13.7, 92.77 ± 4.41 and 93.0 ± 7.90 (p = .001); normal spermatozoa of 69.11% ± 24.90, 90.00% ± 5.15 and 80.66 ± 16.04 (p = .05); live/dead (%) from 64.44 ± 22.86 to 85.33 ± 8.41 (p = .001); and spermatozoa (%) with integral membrane in the membrane integrity (HOST) test ranging from 76.44 ± 20.74 to 91.22 ± 4.68 (p = .05). Serum levels of testosterone (ng/ml) increased from 5.50 ± 1.13 to 8.84 ± 1.13 at D90 (p = .003) and decreased after 2 months (D150) to 5.13 ± 1.13. In conclusion, a 90-day supplementation with salmon oil had a positive influence on semen quality and serum testosterone levels. The supplementation of omegas 3 and 6 at the ratio of 10:1 for 90 days determined an increase in concentration and motility of the sperm, and these effects were maintained for 60 days, with the only exception of testosterone levels.

Preventative Effects of Vitamin E on Testicular Damage and Sperm Parameters in the First-Generation Mice Pups due to Pre- and Postnatal Mancozeb Exposure

The present study aimed to evaluate the effects of vitamin E on mancozeb-induced testis damage of the first-generation pups during intrauterine and lactating periods. Two groups of pregnant NMRI mice received 500 mg/kg mancozeb (MNZ) as MNZ group and 200 mg/kg vitamin E as MNZ+vit.E group before receiving MNZ. In addition, a vehicle and a control group were designed every other day in gestation and lactation periods. The male pups from each group were maintained until adulthood (8-10 W). The left testes and epididymides were removed following the sacrifice of the pups. Then, they were weighed, and sperm parameters including number, viability, motility, and morphology and testis structure were evaluated. A significant decrease occurred in sperm parameters of the mancozeb-treated pups compared to the control and vehicle groups. Treatment with vitamin E reversed the deleterious effects of MNZ to a nearly normal condition. Testis parameters including the weight, gonadosomatic index, seminiferous tubule diameters, and Johnsen's score, as well as the number of germ cells such as spermatogonia, spermatocyte, spermatid, and Sertoli, decreased significantly in the MNZ group, compared to the amount in the control and vehicle groups. Interestingly, the treatment with vitamin E was reversed in most of these parameters. Based on the results, the exposure of pups to mancozeb during pregnancy and lactating periods negatively affects the reproductive system of male pups. However, the coadministration of vitamin E could prevent the deleterious effects of mancozeb on sperm and testis parameters.

Dietary Antioxidant Intake in Relation to Semen Quality Parameters in Infertile Men: a Cross-Sectional Study

The objective of this study was to assess the association between dietary antioxidant intake and semen quality parameters in infertile men. In this cross-sectional study, dietary antioxidant intake was evaluated in 175 infertile Iranian men by a validated dish-based 106-item semi-quantitative food frequency questionnaire. Men were asked to abstain from ejaculation for at least 72 hours before sample collection. Semen parameters were assessed by a sperm counting chamber and Terminal deoxynucleotidyl transferase dUTP nick end labeling assay methods. Linear quantile regression was used to determine the associations between antioxidant nutrient intake and semen quality parameters (including total sperm count, sperm density, total motility, DNA damage and DNA fragmentation). Mean age of study participants was 32.19 ± 2.34 years. Compared with the lowest quartile, men in the highest quartile of dietary β-carotene and vitamin C intake had lower sperm DNA fragmentation index (P_trend = 0.042 and P_trend = 0.03, respectively). Also, dietary intake of beta-cryptoxanthin had a positive association with sperm density (P_trend = 0.02), and dietary lutein was associated with total sperm count (P_trend = 0.045). Dietary intake of other antioxidants did not significantly correlate with the indicators related to the quantity and quality of sperm (p > 0.05). These data suggest that dietary intake of some of the antioxidants is associated with semen related parameters.

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

The effects of oral antioxidants on the semen of men with idiopathic oligoasthenoteratozoospermia

It has been estimated that approximately 15% of reproductive-age couples suffer from infertility. Male factors contribute to almost half of infertility cases, and in many patients the underlying cause of oligoasthenoteratozoospermia is unknown. Accumulating evidence suggests that oxidative stress plays a role as a contributing factor to male infertility, and reactive oxygen species have been shown to impair sperm function and motility and to damage sperm membrane and DNA. Therefore, this review explored the evidence provided by studies published from 2002 to 2017 on the impact of oral antioxidants (vitamin C, vitamin E, L-carnitine, coenzyme Q10, zinc, selenium, and pentoxifylline) on seminal fluid parameters in men with idiopathic oligoasthenoteratozoospermia. Most of the studies were randomized controlled studies that investigated the effect of single or combined antioxidants and reported improvements in at least one semen parameter. The most noteworthy effect that was found was that the use of multiple antioxidants increased sperm motility and concentration. Nonetheless, there is a lack of agreement on the dose, the duration of treatment, and whether individual or combined oral antioxidants should be used. Therefore, the current review provides evidence supporting the use of oral antioxidants in the treatment of infertile men with idiopathic oligoasthenoteratozoospermia.

Discrepancies between the internet and academic literature regarding vitamin use for male infertility

Background

The accuracy of online medical information is variable. A 2014 Cochrane review did not support a robust improvement in male infertility after antioxidant supplementation. Many subfertile men take vitamins in hopes of improving their fertility. We sought to evaluate the content of online information for male fertility vitamins, and compare this with the published literature.

Methods

We searched Google to assess online information regarding vitamins and male infertility. Websites were evaluated for authorship, content, claims and validity. We then reviewed the Recommended Daily Allowance and upper tolerable intake level for each vitamin, and compared this with the supplements actual content.

Results

Four websites were posted by an academic source, 7 private clinic, 31 industry, 8 were patient blogs and 50 other sources. Reproductive claims made by websites included: Improved sperm count: 65; improved pregnancy rates: 42; improved live birth rates: 9; healthier offspring: 18. Overall, 76 websites claimed some improvement in semen parameters; 85 claimed some improved reproductive outcome. 26 websites were supported by peer-reviewed literature. None of the supplements had more than the upper tolerable intake level of any of the vitamins, but several were over the RDA, most commonly zinc, vitamin B12 and selenium.

Conclusions

Many websites claim improvements in a variety of male reproductive outcomes after vitamin supplementation. These are often not supported by the medical literature. We need to provide evidence-based information to patients so that they can have realistic expectations of the benefits that vitamins may have on male reproductive outcomes.

Troxerutin protect sperm, seminiferous epithelium and pituitary-gonadal axis from torsion-detorsion injury: An experimental study

BACKGROUND

Troxerutin is a flavonoid antioxidant that protect different organ against damage caused by ischemia-reperfusion.

OBJECTIVE

The aim of this study was to evaluate the effect of troxerutin in reducing the damages caused by ischemia-reperfusion in rat's testis.

MATERIALS AND METHODS

40 Male Wistar rats (2 month old) were divide to four groups (n=10). Group1 (sham), Group 2 (control, ischemia-reperfusion (I/R) without treatment), Group 3 (I/R+150 mg/kg of troxerutin), and group 4 (I/R+20 mg/kg of vitamin C). Treatment of group 3 and group 4 during torsion (twists 720 counter clock at 90 min) followed by 50 days detorsion. After 50 days, blood samples were collected and rats in all study groups were killed and their testes were removed, and fixed with Bouin's solution. Testis was stained with hematoxylin and eosin dye and the level of testosterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured with ELISEA methods. TUNEL was employed to detect apoptosis. Epididymis caudal part was removed and total sperm count was determined. Johnson techniques were used for assessment of seminiferous tubules quality.

RESULTS

Troxerutin treated group has higher Johnson score's (p≤0.001), antiapoptotic properties (p≤0.001), sperm count (p=0.065), and higher LH (p≤0.001), FSH (p≤0.001) and testosterone (p=0.002) levels than control group. Vitamin C treated group showed increase level of testosterone but didn't show significant differences on the number of apoptotic cells, Johnson scores, LH, FSH and sperm count than control group.

CONCLUSION

Troxerutin has protective effects on testicular torsion induced injury and can ameliorate spermatogenesis in the torsion-detorsion models.

Quercetin and rutin ameliorates sulphasalazine-induced spermiotoxicity, alterations in reproductive hormones and steroidogenic enzyme imbalance in rats

Certain dietary flavonoids exhibit protective potentials against drug-induced male reproductive toxicities. We investigated the protective effects of quercetin and rutin on sulphasalazine-induced alterations in steroidogenic enzyme activity, hormone profile and spermiotoxicity in rats. Sulphasalazine (SASP, 600 mg/kg bw) was administered alone or in combination with quercetin (20 mg/kg bw) or rutin (10 mg/kg bw) for 14 days. SASP treatment significantly increased relative weights of the epididymis and seminal vesicles. Also, testicular and epididymal sperm numbers (TSN, ESN), motility, daily sperm production (DSP) and acrosome reaction (AR) significantly decreased. SASP altered plasma testosterone, luteinising hormone (LH) and follicle-stimulating hormone (FSH) levels while testicular cholesterol levels, 3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β-hydroxysteroid dehydrogenase (17β-HSD) activities were decreased. Elevated malondialdehyde levels and concomitant decrease in reduced glutathione, glutathione-S-transferase, peroxidase and superoxide dismutase activities were evident in testis and epididymis of SASP-treated rats. Quercetin or rutin co-treatment with SASP significantly reversed organ weights, preserved sperm integrity, restored plasma hormone levels and increased cholesterol levels, 3β-HSD and 17β-HSD activities in testis. Both flavonoids also prevented oxidative stress in testis and epididymis of SASP-treated rats. Quercetin and rutin protect against the negative effects of SASP treatment on reproductive capacity in male rats.

Effect of in vitro vitamin E (alpha-tocopherol) supplementation in human spermatozoon submitted to oxidative stress

The aim of this study was to evaluate the antioxidant effect of in vitro supplementation with vitamin E in human spermatozoon incubated with an oxidative stress inducer. In this study, semen samples from 30 patients were collected and with one aliquot we performed semen analysis according to WHO. The remaining volume was divided into four aliquots: group C: incubated with BWW medium; group I: incubated with 5 mmol 1-1 hydrogen peroxide; group A: incubated with 40 μmol 1-1 vitamin E; and group AI: incubated with both them. After incubations, sperm functional analyses were performed and included: evaluation of oxidative stress, acrosome integrity, mitochondrial activity and DNA fragmentation. Groups were compared using a Friedman test with Bonferroni post hoc (α = 5%). In this study, we observed that in group I there was a decrease in acrosome integrity and mitochondrial activity, and an increase in DNA fragmentation, when compared to group C. Group AI showed an increase in acrosome integrity and mitochondrial activity when compared with group I. Based on our findings, we conclude that the vitamin E supplementation had a positive effect in protecting human spermatozoon from induced oxidative stress.

A chemical compound based on methylxanthine-polyphenols lowers nitric oxide levels and increases post-thaw human sperm viability

We produced a new chemical compound based on methylxanthines and polyphenols (CCMP) present in the chemical matrix of guaraná (Paullinia cupana), a seed extract with antioxidant properties. After supplementation with the standard extract of resveratrol, a well documented antioxidant found in other plant sources, we investigated whether this resveratrol-enriched compound could improve sperm viability and modulate differentially reactive oxygen species (ROS) and nitric oxide (NO) levels in thawed sperm. Sperm samples obtained from healthy young donors were treated with different concentrations of guaraná extract (0.1, 1, 5 or 10 mg/ml) and cells were frozen at -80°C for 24 h. In addition, the potential protective effects of guaraná treatment on sperm treated with pro-oxidant compound (200 µM hydrogen peroxide, H2O2) were assessed. Samples were also exposed to three concentrations of CCMP before being frozen in liquid nitrogen (-196°C) or in an ultrafreezer (-80°C) for 24 h, and both pre-freezing and post-thaw measurements of viability and oxidative stress were performed. Guaraná supplementation at 10 mg/ml significantly increased post-thaw viability and decreased oxidative metabolism of the sperm. Moreover, selected concentrations of CCMP improved viability and oxidative metabolism in sperm samples pre-freezing. Furthermore, CCMP showed cryoprotective activity by increasing viability and decreasing oxidative stress in post-thaw samples. In summary, these findings suggested that CCMP supplementation acts as a cryoprotectant to modulate ROS and NO levels in thawed sperm. CCMP could be used to enhance sperm quality and reproductive success.

Protective effect of Propolfenol® on induced oxidative stress in human spermatozoa

The propolis extract was shown to possess the capacity to protect sperm membrane from the deleterious action of oxidative attack. Oxidative stress can induce propagation of a lipid peroxidation (LPO) chain reaction because spermatozoa contain high concentration of unsaturated fatty acids. This study aimed at evaluating in vitro the possible toxicity and/or the antioxidant properties of Propolfenol^® in ejaculated human spermatozoa. A colorimetric assay determined the total flavonoid content by spectrophotometry and a high-performance liquid chromatography-diode array detection analysis the quantity of galangin, pinocembrin and caffeic acid phenylethilic ester (CAPE). Sperm parameters such as motility, vitality and DNA integrity were assessed utilising optical microscopy. The antioxidant properties Propolfenol^® against LPO induced by tert-Butyl Hydroperoxide were evaluated using the C11-BODIPY581/591 probe. Chemical analysis of Propolfenol^® revealed low quantities of galangin, pinocembrin and CAPE; cyclic voltammetry experiments showed that Propolfenol^® may exert an antioxidant activity. A protective action of Propolfenol^® (20 and 100 μg/ml) on induced LPO in human spermatozoa was detected. Propolfenol^® may be proposed as the supplement in media for sperm preparation techniques or cryopreservation to counteract the increased presence of reactive oxygen species generated by these methods.

Role of Antioxidants in Assisted Reproductive Techniques

Oxidative stress (OS) has been recognized as a significant cause of suboptimal assisted reproductive outcome. Many of the sperm preparation and manipulation procedures that are necessary in the in vitro environment can result in excessive production of reactive oxygen species (ROS) thereby exposing the gametes and growing embryos to significant oxidative damage. Antioxidants have long been utilized in the management of male subfertility as they can counterbalance the elevated levels of ROS inducing a high state of OS. Few studies have looked into the clinical effectiveness of antioxidants in patients undergoing assisted reproduction. While an overall favorable outcome has been perceived, the specific clinical indication and optimal antioxidant regimen remain unknown. The goal of our review is to explore the sources of ROS in the in vitro environment and provide a clinical scenario-based approach to identify the circumstances where antioxidant supplementation is most beneficial to enhance the outcome of assisted reproduction.

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.

Varicocele management in the era of in vitro fertilization/intracytoplasmic sperm injection

Varicocele is the most common surgically treatable cause of male infertility, and often results in alterations in semen parameters, sperm DNA damage, and changes to the seminal milieu. Varicocele repair can result in improvement in these parameters in the majority of men with clinical varicocele; data supporting repair in men with subclinical varicocele are less definitive. In couples seeking fertility using assisted reproductive technologies (ARTs), varicocele repair may offer improvement in semen parameters and sperm health that can increase the likelihood of successful fertilization using techniques such as in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI), or may decrease the level of ART needed to achieve successful pregnancy. Male infertility is an indicator of general male health, and evaluation of the infertile male with an eye toward future health can facilitate optimal screening and treatment of these men. Furthermore, varicocele may represent a progressive lesion, offering an argument for its repair, although this is currently unclear.

Protective effect of crocetin on bovine spermatozoa against oxidative stress during in vitro fertilization

Oxidative stress is one of the major factors that contribute to poor semen quality and low rates of in vitro fertilization. Crocetin, a main constituent of saffron (Crocus sativus L.) possesses potent antioxidant activity, by scavenging reactive oxygen species (ROS) and/or enhancing the activity of intracellular antioxidant enzymes. The aim of this study was to investigate, for the first time, the effect of crocetin on the quality characteristics of bull spermatozoa and fertilization rate. For this reason, frozen/thawed bovine spermatozoa were incubated with crocetin (1, 2.5, and 5 μm), for 120 or 240 min, in the presence of a negative control, and evaluated in terms of motility, viability, acrosomal status, DNA fragmentation index, intracellular ROS, and lipid peroxidation. In order to evaluate the impact of crocetin on cleavage and blastocyst rate, the compound was added in the IVF medium at the previously identified optimal concentration (2.5 μm). The results indicate that incubation of spermatozoa with 2.5 μm of crocetin resulted in a statistically significant lower production of superoxide anion and hydrogen peroxide, lower lipid peroxidation, and in better maintenance of motility parameters, viability, and acrosomal integrity, with a very small number of cells with DNA fragmentation, compared to the other groups (p < 0.05). The presence of crocetin (2.5 μm) in the fertilization medium also resulted in a significant increase in acrosome-reacted spermatozoa and blastocyst production, compared to the control group (p < 0.01). These data indicate that crocetin (2.5 μm) positively affects bovine sperm quality characteristics during a 240-min incubation and improves its fertilizing ability, directly and/or indirectly, by regulating ROS concentration and lipid peroxidation.

Genotoxicity and antigenotoxicity study of aqueous and hydro-methanol extracts of Spondias mombin L., Nymphaea lotus L. and Luffa cylindrical L. using animal bioassays

Spondias mombin (Linn), Nymphaea lotus (Linn) and Luffa cylindrica (Linn) (syn Luffa aegyptiaca Mill) are plants traditionally used as food ingredients and in the management of diseases, including cancer, in Nigeria. Despite the therapeutic potentials attributed to these plants, reports on their genotoxicity are scanty. In this study, the genotoxicity of the aqueous and hydro-methanol extract of these plants was evaluated using mouse bone marrow micronucleus and sperm morphology assays. Antigenotoxicity was assessed by the bone marrow micronucleus test. The highest attainable dose of 5 000 mg/kg according to OECD guidelines was first used to assess acute toxicity of the aqueous and hydro-methanol extracts in Swiss albino mice. For each extract, there were five groups of mice (n=4/group) treated with different concentrations of the extract as against the negative and positive control group for the genotoxicity study. In the antigenotoxicity study, five groups of mice were exposed to five different concentrations of the extracts along with 60 mg/kg of methyl methane sulfonate (MMS), which was used to induce genotoxicity. The mice were administered 0.2 mL of extract per day for 10 days in the genotoxicity and antigenotoxicity groups. Administration of each of the extracts at the concentration of 5 000 mg/kg did not induce acute toxicity in mice. At the concentrations tested, all the extracts, except aqueous S. mombin, increased micronucleated polychromatic erythrocytes. The aqueous and hydro-methanol extracts of N. lotus increased the frequency of aberrant sperm cells. All the extracts were also able to ameliorate MMS induced genotoxicity in bone marrow cells of the exposed mice. The results showed the potential of the extracts to induce somatic and germ cell mutation in male mice. The extracts also ameliorated the genotoxic effect of MMS.

Varicocele and testicular function

Testicular varicocele, a dilation of the veins of the pampiniform plexus thought to increase testicular temperature via venous congestion, is commonly associated with male infertility. Significant study has clarified the negative impact of varicocele on semen parameters and more recent work has shed light on its detrimental effects on the molecular and ultrastructural features of sperm and the testicular microenvironment, as well as more clearly defined the positive impacts of treatment on couples’ fertility. The relationship between varicocele and testicular endocrine function, while known for some time based on histologic evaluation, has become more apparent in the clinical setting with a growing link between varicocele and hypogonadism. Finally, in the pediatric setting, while future study will clarify the impact of varicocele on fertility and testicular function, recent work supports a parallel effect of varicocele in adolescents and adults, suggesting a re-evaluation of current treatment approaches in light of the progressive nature of the condition and potential increased risk of future disease.

Effect of Quercetin-loaded liposomes on induced oxidative stress in human spermatozoa

A strategy to circumvent the poor polyphenols bioavailability is to load these compounds into liposomes. We evaluated the in vitro effects of quercetin (Q) and Q-loaded liposomes (QLL, 30, 50, 100μM) on motility, viability and chromatin integrity of swim-up selected human sperm. Antioxidant power was assayed against tert-butylhydroperoxide induced lipid peroxidation (LPO) using C11-BODIPY581/591 fluorescent probe and transmission electron microscopy. QLL showed decreased toxicity for sperm motility and viability and increased DNA damage compared to Q. The percentage of sperm with fluorescence, marker of LPO, was decreased in samples incubated with Q vs QLL (P<0.001). The ultrastructure of acrosomes and membranes was preserved with Q 30/100μM, whereas QLL did not prevent membrane injury. Q alone appeared more effective than Q incorporated into liposomes; however liposomes could be considered as carriers that may convey different compounds inside sperm; they may therefore represent a field of research rich of many applications.

An Ecology of Sperm: Sperm Diversification by Natural Selection

Using basic ecological concepts, we introduce sperm ecology as a framework to study sperm cells. First, we describe environmental effects on sperm and conclude that evolutionary and ecological research should not neglect the overwhelming evidence presented here (both in external and internal fertilizers and in terrestrial and aquatic habitats) that sperm function is altered by many environments, including the male environment. Second, we determine that the evidence for sperm phenotypic plasticity is overwhelming. Third, we find that genotype-by-environment interaction effects on sperm function exist, but their general adaptive significance (e.g., local adaptation) awaits further research. It remains unresolved whether sperm diversification occurs by natural selection acting on sperm function or by selection on male and female microenvironments that enable optimal plastic performance of sperm (sperm niches). Environmental effects reduce fitness predictability under sperm competition, predict species distributions under global change, explain adaptive behavior, and highlight the role of natural selection in behavioral ecology and reproductive medicine.

Utility of antioxidants during assisted reproductive techniques: an evidence based review

Assisted reproductive technology (ART) is a common treatment of choice for many couples facing infertility issues, be it due to male or female factor, or idiopathic. Employment of ART techniques, however, come with its own challenges as the in vitro environment is not nearly as ideal as the in vivo environment, where reactive oxygen species (ROS) build-up leading to oxidative stress is kept in check by the endogenous antioxidants system. While physiological amounts of ROS are necessary for normal reproductive function in vivo, in vitro manipulation of gametes and embryos exposes these cells to excessive ROS production either by endogenous or exogenous environmental factors. In this review, we discuss the sources of ROS in an in vitro clinical setting and the influence of oxidative stress on gamete/embryo quality and the outcome of IVF/ICSI. Sources of ROS and different strategies of overcoming the excessive generation of ROS in vitro are also highlighted. Endogenously, the gametes and the developing embryo become sources of ROS. Multiple exogenous factors act as potential sources of ROS, including exposure to visible light, composition of culture media, pH and temperature, oxygen concentration, centrifugation during spermatozoa preparation, ART technique involving handling of gamete/embryo and cryopreservation technique (freeze/thawing process). Finally, the use of antioxidants as agents to minimize ROS generation in the in vitro environment and as oral therapy is highlighted. Both enzymatic and non-enzymatic antioxidants are discussed and the outcome of studies using these antioxidants as oral therapy in the male or female or its use in vitro in media is presented. While results of studies using certain antioxidant agents are promising, the current body of evidence as a whole suggests the need for further well-designed and larger scale randomized controlled studies, as well as research to minimize oxidative stress conditions in the clinical ART setting.