Role of Oxidative Stress in Male Infertility: An Updated Review

JAK Inhibition Prevents DNA Damage and Apoptosis in Testicular Ischemia-Reperfusion Injury via Modulation of the ATM/ATR/Chk Pathway

Testicular ischemia reperfusion injury (tIRI) causes oxidative stress-induced DNA damage leading to germ cell apoptosis (GCA). The aim of the study is to establish a direct link between JAK2 activation and the DNA damage response (DDR) signaling pathways and their role in tIRI-induced GCA using AG490, a JAK2 specific inhibitor. Male Sprague Dawley rats (n = 36) were divided into three groups: sham, unilateral tIRI and tIRI + AG490 (40 mg/kg). During tIRI, augmentation in the phosphorylation levels of the JAK2/STAT1/STAT3 was measured by immunohistochemistry. Observed spermatogenic arrest was explained by the presence of considerable levels of DSB, AP sites and 8OHdG and activation of caspase 9, caspase 3 and PARP, which were measured by colorimetric assays and TUNEL. The ATM/Chk2/H2AX and ATR/Chk1 pathways were also activated as judged by their increased phosphorylation using Western blot. These observations were all prevented by AG490 inhibition of JAK2 activity. Our findings demonstrate that JAK2 regulates tIRI-induced GCA, oxidative DNA damage and activation of the ATM/Chk2/H2AX and ATR/Chk1 DDR pathways, but the cell made the apoptosis decision despite DDR efforts.

Effect of glutathione S-transferase gene polymorphisms on semen quality in patients with idiopathic male infertility

OBJECTIVE

To investigate the relationship between glutathione S-transferase enzyme (GSTM1, T1, and P1) genetic variants and semen quality in men with idiopathic infertility.

METHODS

Sperm characteristics were measured using computer-assisted sperm analysis. The malondialdehyde (MDA), nitric oxide (NO), and total antioxidant capacity (TAC) activities were detected by spectroscopic analysis, and 8-hydroxy-2'-deoxyguanosine (8-OHdG) was detected by enzyme-linked immunosorbent assay.

RESULTS

This study included 246 idiopathic infertile men and 117 controls. The GSTM1(-), T1(-), and M1/T1(-/-) genotype frequencies significantly differed between the groups. The GSTM1(-) and T1(-) genotypes in idiopathic infertile men negatively correlated with sperm concentration, motility, mitochondrial membrane potential, and other parameters. However, these genotypes positively correlated with the amplitude of the lateral head displacement and NO and 8-OHdG levels. The GSTT1(-) genotype positively correlated with mean angular displacement and MDA activity. GSTM1(-) and T1(-) had a synergistic effect on semen quality. Sperm motility, normal morphology, straightness, and TAC were lower and amplitude of lateral head displacement and MDA were higher in the GSTP1(A/G + G/G) group than in the GSTP1(A/A) group among men with idiopathic infertility.

CONCLUSIONS

GSTM1, T1, and P1 genetic variants may be risk factors for infertility by affecting the semen quality men with idiopathic oligoasthenospermia.

Impact of insulin producing cells derived from adipose tissue mesenchymal stem cells on testicular dysfunction of diabetic rats

The present study is to clarify the effect of insulin-producing cells (IPCs) derived from adipose tissue mesenchymal stem cells (AT-MSCs) on diabetic-induced impairments as the abnormalities of testicular tissues, oxidative stress of testes, and defects of spermatogenesis. Diabetes was stimulated by streptozotocin (STZ) injection in male adult Sprague Dawley (SD) rats. Diabetes was confirmed by taking two highly consecutive fasting blood sugar readings; more than 300 mg/dl; within one week. Five million of IPCs derived from AT-MSCs; encased in TheraCyte capsule; were then directly transplanted (one implant for each rat) subcutaneously in diabetic rats. Implants were maintained for 3 months and the fasting blood sugar of the transplanted rats was observed every month. At the end of the experiment; serum testosterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were also estimated. The sperm parameters (count, motility, and abnormality) were recorded. In testicular tissue; GPX4, Bcl2, and Bax levels were evaluated, while oxidative stress and antioxidant enzymes activities were measured in the testes homogenate. Also, histopathological alterations were examined in the testes cross-section. In the results, it was found that IPCs treatment enhanced the serum testosterone, FSH, and LH levels. Diabetic-induced impairments in the sperm parameters were noticeably improved post-IPCs transplantation in the diabetic rats. Moreover, the treatment improved the diabetic-associated testicular oxidative stress. Also, it was recognized that the Bax expression decreased, while, GPX4 and Bcl2 expression increased in the treated rats. Meanwhile, the abnormalities showed in the histopathological studies of the hyperglycemic rat's testes were attenuated post-treatment. So, IPCs transplantation improved diabetes and consequently protected against hyperglycemia-induced testicular damages.

Thymoquinone ameliorates bleomycin-induced reproductive toxicity in male Balb/c mice

Bleomycin (BL) is a powerful chemotherapy drug that has devastating effects on spermatogenic function and may make cancer survivors at risk of infertility. Protective effects of thymoquinone (TQ), a phytochemical compound with antioxidant and anticancer influences, were investigated on sperm parameters, testicular structures, and sexual hormones in BL-treated mice. Forty-eight adult male Balb/c mice were randomly divided into six groups. Control group received normal saline; BL group received 10 mg/kg BL; TQ7.5 group received 7.5 mg/kg TQ; TQ15 group received 15 mg/kg TQ; BL+TQ7.5 group received 10 mg/kg BL and 7.5 mg/kg TQ; BL + TQ15 group received 10 mg/kg BL and 15 mg/kg TQ. BL was intraperitoneally used every day through 35 days, and TQ was intraperitoneally injected 3 days before administration of BL and continued twice per week for 35 days. Results showed that BL significantly decreased count, viability, morphology, maturity, and progressive movement of sperm, testosterone, seminiferous tubule diameters, the ratio of testis weight to body weight, number of spermatogonia, spermatocytes, spermatids, and Sertoli cells per tubule, and expression of Bcl2l1 and Bcl2l1/Bax ratio, and increased the non-progressive movement and immotile sperm, intermediate and immature sperm, LH, FSH, and malondialdehyde levels, and tunica albuginea thickness compared to the control group (p < .05). TQ at a level of 7.5 mg/kg ameliorated BL-induced toxicity on measured parameters and returned most of them to the level of the control group. These data suggested TQ in a dose-dependent manner may have positive effects on BL-induced toxicity of the testis in mice model.

Effectiveness of Exercise Training on Male Factor Infertility: A Systematic Review and Network Meta-analysis

CONTEXT

Mounting evidence from the literature suggests that different types of training interventions can be successful at improving several aspects of male reproductive function in both fertile and infertile populations.

OBJECTIVE

The aim of this study was to evaluate the effectiveness of exercise training on male factor infertility and seminal markers of inflammation.

DATA SOURCES

We searched PubMed, CISCOM, Springer, Elsevier Science, Cochrane Central Register of Controlled Trials, Scopus, PEDro, Ovid (Medline, EMBASE, PsycINFO), Sport Discus, Orbis, CINAHL, Web of Science, ProQuest, and the ClinicalTrials.gov registry for randomized controlled trials (RCTs) that analyzed the impacts of selected types of exercise interventions on markers of male reproductive function and reproductive performance.

STUDY SELECTION

A total of 336 records were identified, of which we included 7 trials reporting on 2641 fertile and infertile men in the systematic review and network meta-analysis.

LEVEL OF EVIDENCE

Level 1 (because this is a systematic review of RCTs).

DATA EXTRACTION

The data included the study design, participant characteristics, inclusion and exclusion, intervention characteristics, outcome measures, and the main results of the study.

RESULTS

The results of network meta-analysis showed that, compared with a nonintervention control group, the top-ranking interventions for pregnancy rate were for combined aerobic and resistance training (CET) (relative risk [RR] = 27.81), moderate-intensity continuous training (MICT) (RR = 26.67), resistance training (RT) (RR = 12.54), high-intensity continuous training (HICT) (RR = 5.55), and high-intensity interval training (HIIT) (RR = 4.63). While the top-ranking interventions for live birth rate were for MICT (RR = 10.05), RT (RR = 4.92), HIIT (RR = 4.38), CET (RR = 2.20), and HICT (RR = 1.55). Also, with the following order of effectiveness, 5 training strategies were significantly better at improving semen quality parameters (CET > MICT > HICT > RT > HIIT), seminal markers of oxidative stress (CET > MICT > HIIT > HICT > RT), seminal markers of inflammation (CET > MICT > HIIT > RT > HICT), as well as measures of body composition and VO₂max (CET > HICT > MICT > HIIT > RT).

CONCLUSION

The review recommends that the intervention with the highest probability of being the best approach out of all available options for improving the male factor infertility was for CET.

Lepidium draba L. leaves extract ameliorated cyclophosphamide-induced testicular toxicity by modulation of ROS-dependent Keap1/Nrf2/HO1, Bax/Bcl2/p53/caspase-3, and inflammatory signaling pathways

The aim of this study was to evaluate the protective effects of Lepidium draba L. extract on cyclophosphamide (CP)-induced oxidative damages to testes in rats using sex hormones, antioxidant properties, inflammatory, and apoptotic pathways. Six groups of male Wistar rats (n = 6/group) received distilled water (NC), CP (100 mg kg^-1  day^-1 /intraperitoneal), CP with L. draba extract [100 (LDCP 100), 200 (LDCP 200), and 400 (LDCP 400) mg/kg/day/orally] and also only L. draba extract [400 (LD400) mg/kg/day/orally] in 35 days. On day 36 of the study, sperm parameters, serum levels of sex hormones, antioxidant enzyme activity, nitric oxide levels, and inflammatory cytokines and also testicular tissue (ferric reducing antioxidant power and thiobarbituric acid reactive substances levels and expression of ROS-dependent pro/anti-apoptotic pathways) were evaluated. In L. draba-treated groups, especially doses of 200 and 400, in addition to improving sperm parameters and sex hormones (Increased levels of all three hormones luteinizing hormone, follicle-stimulating hormone, and testosterone), serum antioxidant (catalase, superoxide dismutase, and glutathione peroxidase activity increased and nitric oxide levels decreased), and anti-inflammatory properties (levels of IL-6, TNF-α, and IL-1β decreased and MIF and TGF-β increased) also showed modification. By strengthening the anti-apoptotic pathway of Keap1/Nrf2/HO1 and inhibiting the apoptotic pathway of Bax/Bcl2/p53/caspase-3, L. draba maintains the structure and function of testicular tissue so that eventually p53-positive testicular cells are reduced and Bcl-2-positive cells increased. L. draba can help to maintain sexual potency and fertility in patients undergoing chemotherapy by controlling their apoptotic, anti-inflammatory, and antioxidant pathways. PRACTICAL APPLICATIONS: Lepidium draba have considerable antioxidant properties and can help to maintain sexual potency and fertility in patients undergoing chemotherapy by controlling their apoptotic, anti-inflammatory, and antioxidant pathways. The present results are useful to find a suitable supplement for improving the sexual performance of patients treated with chemotherapy drugs.

The effect of curcumin on embryonic in vitro development in experimental polycystic ovary syndrome: An experimental study

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common disease in women. Some plant compounds which have antioxidant properties, such as curcumin, may be useful for these patients when delivered orally or in vitro.

OBJECTIVE

The aim of this study was to evaluate the impact of PCOS on oocyte quality and the effect of curcumin on in vitro fertilization of oocytes.

MATERIALS AND METHODS

In this experimental study, Naval Medical Research Institute mice aged six to eight wk were used. Mice were divided into five experimental groups (control, experimental PCOS, curcumin 6, 12 and 24 μM). To induce experimental PCOS, estradiol valerate (100 mg/kg, IP) was injected. The total antioxidant capacity and production of malondialdehyde in ovarian tissue and blood serum were evaluated in all groups. Finally, 6, 12 and 24 μM of curcumin were added to the culture medium of the PCOS group oocytes and development in the different groups was evaluated.

RESULTS

A high percentage of oocytes for fertilization were not in good condition in terms of number and quality in the group of PCOS. The addition of curcumin to the embryo culture medium was associated with a higher percentage of fertilized oocytes, two-cells and blastocysts. This increase was significant at a concentration of 24 μM (p ≤ 0.01).

CONCLUSION

Given that adding curcumin seemed to improve fetal growth and prevent the harmful effects of oxygen free radicals on the culture medium, it is recommended to add a certain concentration of curcumin under normal conditions without oxidative stress.

Indicators of the Lipid Peroxidation-Antioxidant Protection System as Important Metabolic Markers of Reproductive Potential in Men

We analyze results of recent studies demonstrating unfavorable state of the reproductive health in the male population that manifested not only in spermatogenesis deterioration, but also in oxidative stress (both systemic and in seminal fluid). The data on the effect of ROS and components of the antioxidant defense system on gamete quality in men with infertility associated with obesity and diabetes mellitus are presented. Some features of oxidative stress in men of reproductive age of various ethnic groups are shown. Evaluation of the parameters of oxidative stress provides new insight into the molecular mechanisms of functional activity of the semen and may become a promising direction for the development of new methodological recommendations for personalized diagnosis, prevention, and correction of reproductive disorders in men.

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

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

Vitamin D3 Supplementation Effects on Spermatogram and Oxidative Stress Biomarkers in Asthenozoospermia Infertile Men: a Randomized, Triple-Blind, Placebo-Controlled Clinical Trial

The objective is to evaluate the effects of vitamin D3 (VD3) on sperm parameters and seminal and serum oxidative stress (OS) biomarkers in asthenozoospermia infertile men. This randomized, triple-masking, placebo-controlled clinical trial conducted on 86 asthenozoospermia infertile men with serum 25 hydroxy vitamin D3 (25-OH-D3) < 30 ng/ml in the infertility clinic of Ahvaz Jahad Daneshgahi, Iran. Patients were randomly allocated to groups A and B, who received daily 4000 IU vitamin D3 (VD3) and matching placebo respectively for 3 months. Demographic data, dietary intake, physical activity, sun exposure, anthropometric indices, serum and seminal levels of MDA (Malondialdehyde), 8-hydroxy-2- Dioxy Guanosine (8-OHDG), total antioxidant capacity (TAC) and calcium, sperm DNA fragmentation index (DFI), serum 25-OH-D3, parathyroid hormone (PTH), phosphorus, and sperm parameters were assessed. VD3 supplementation had no significant effects on body weight, body mass index (BMI), waist circumference (WC), body fat (BF), 8-OHDG, DFI, semen volume, sperm count, and normal sperm morphology, but increased post-intervention mean and mean change of serum 25-OH-D3 (P < 0.001, P < 0.001), PTH (P < 0.001, P < 0.001) and phosphorus (P = 0.009, P = 0.049) and seminal calcium (P = 0.035, P = 0.038) and serum calcium (P = 0.008, P = 0.009), seminal TAC (P < 0.001, P < 0.001), and serum TAC (P = 0.007, P = 005), total sperm motility (P < 0.001, P < 0.001) and progressive sperm motility (P < 0.001, P < 0.001) and decreased seminal MDA (P = 0.017, P = 0.004) and serum MDA (P = 006, P = 0.005) significantly compared to the baseline and placebo group respectively. VD3 supplementation may modulate OS and affect sperm motility in men with asthenozoospermia and serum 25-OH-D3 < 30 ng/ml. Iran Clinical Trials Registry, ID: IRCT20151128025274N4, registered on 28 March 2018, URL of trial registry record: https://www.irct.ir/trial/29983.

Dysregulation of mitochondrial sirtuin genes is associated with human male infertility

Mitochondrial sirtuins (SIRT3, SIRT4, SIRT5) are post-translational modifiers that regulate energy production, body homeostasis and mitochondrial activities via different substrates in response to environmental stressors. The present study aimed at assessing the expression of SIRT3, SIRT4, and SIRT5 in the semen of infertile men. Expression analysis was performed using q-RT PCR. All mitochondrial sirtuin genes were significantly down-regulated in the semen of infertile men compared to fertile men. Mitochondrial sirtuin genes expression levels were correlated with mitochondrial HSP90 expression. HSP90 expression was positively correlated with SIRT3, SIRT4 and SIRT5 expression in the semen of fertile men, while a negative correlation was observed between HSP90 in the semen of infertile men and mitochondrial sirtuin genes in the semen of fertile men. These data suggest that dysregulation of mitochondrial sirtuin genes causes mitochondrial dysfunction due to stress, which appears to be associated with human male infertility by compromising functional and structural sperm integrity.

Effects of progesterone nanoparticles on the sperm capacitation and acrosome reaction in asthenozoospermia men

Low motility is one of the causes of male infertility. In this study, the effects of progesterone solid lipid nanoparticles (SLNs) on sperm capacitation, acrosome reaction, oxidative stress and expression of SPACA1 and MAPK way genes were investigated. Progesterone SLNs were synthesized using the solvent emulsification evaporation method. Twenty asthenozoospermia samples were selected, and sperm and acrosome membrane integrity, acrosome reaction, sperm motility, viability, total antioxidant capacity (TAC), total oxidative status tests and PKA, PTK, P38MAPK and SPACA1 gene expressions were assessed. The synthesized nanoparticles were prepared with the size (187.6 nm), PDI (0.184), EE (85.82%), LP (3.43%) and ZP (-23.5mV). Progesterone SLNs increased sperm and acrosome membrane integrity and TAC (p < .05). Also, the expression of P38MAPK, PKA, PTK, and SPACA1 genes in this group showed a significant increase (p < .001). Progesterone SLNs increased acrosome reaction, sperm capacitation and TAC. Also, it increased the expression of PTK PKA, SPACA1 and P38MAPK genes.

Role of exogenous antioxidants on the performance and function of pig sperm after preservation in liquid and frozen states: A systematic review

In situations where an excessive generation of reactive oxygen species overwhelms antioxidant capacity, a harmful effect on sperm function is exerted. Antioxidants are molecules capable of minimizing this detrimental effect, which is important in pig sperm due to the high content of polyunsaturated fatty acids in their plasma membrane. The present systematic review aims at evaluating whether supplementing semen extenders (for liquid storage at 17 °C) or freezing and/or thawing media (for cryopreservation) with antioxidants influences sperm quality and functionality parameters, and in vitro/in vivo fertility outcomes. We defined inclusion and exclusion criteria in a PICOS table according to PRISMA guidelines, and conducted a literature search through MEDLINE-PubMed in November 2020. After systematic selection, 75 studies were included: 47 focused on cryopreservation and 28 on liquid storage at 17 °C. More than 70% of the studies included in this review showed that adding semen extenders for liquid storage and/or freezing/thawing media for cryopreservation with antioxidants enhances sperm quality and functionality parameters. In addition, this supplementation improves in vivo/in vitro fertility outcomes, supporting the hypothesis that the beneficial effect observed upon sperm quality has a positive impact on reproduction outcomes.

Male subfertility and oxidative stress

To date 15% of couples are suffering from infertility with 45-50% of males being responsible. With an increase in paternal age as well as various environmental and lifestyle factors worsening these figures are expected to increase. As the so-called free radical theory of infertility suggests, free radicals or reactive oxygen species (ROS) play an essential role in this process. However, ROS also fulfill important functions for instance in sperm maturation. The aim of this review article is to discuss the role reactive oxygen species play in male fertility and how these are influenced by lifestyle, age or disease. We will further discuss how these ROS are measured and how they can be avoided during in-vitro fertilization.

Diet Supplemented with Chrysophyllum albidum G. Don (Sapotaceae) Fruit Pulp Improves Reproductive Function in Hypertensive Male Rats

Hypertension has been implicated as a risk factor of reproductive disorders. High blood pressure may trigger impaired sperm quality and biomarkers of reproductive disorders. This study aims to investigate the effect of diet supplemented with Chrysophyllum albidum fruit pulp (FP) on sperm parameters, reproductive hormones, and antioxidant markers in testes and epididymis of hypertensive rats. Male Wistar rats were divided into seven groups (n = 10): normotensive control rats [NC], cyclosporine (25 mg/kg)-induced hypertensive rats [Hypert], hypertensive rats treated with captopril (10 mg/kg/day) [Hypert + Capt], hypertensive [Hypert + 2%FP and Hypert + 4%FP], and normotensive [2%FP and 4%FP] rats treated with 2% and 4% of diet supplemented with African star apple fruit's pulp [FP]. Hemodynamic parameters (arterial pressure, diastolic, and systolic pressure), sperm count, sperm motility, reproductive hormones, reactive oxygen species, and malondialdehyde levels were assessed. Diet supplemented with FP fed to hypertensive rats reduced mean arterial pressure, diastolic and systolic blood pressure, and heart rate. Furthermore, FP improved sperm quality in hypertensive rats by increasing sperm count, sperm motility with a concomitant reduction in sperm abnormality. FP also increased 3β and 17β-hydroxysteroid hydrogenase (3β-HSD and 17β -HSD) activities, as well as testosterone, luteinizing hormone, and follicle-stimulating hormone levels. Besides, FP triggered a significant increase in 3β-HSD, 17β -HSD, and STAR expression in rats' testicular tissues. Diet supplemented with FP also reduced ROS and malondialdehyde levels and triggered an increase in thiol levels, catalase, and glutathione-S-transferase activities. This study revealed that FP supplemented diet improved sexual function in cyclosporine-induced hypertensive rats by reducing blood pressure and modulation of sperm parameters, steroidogenic enzymes, and reproductive hormones.

Protective Effect of Nano-Vitamin C on Infertility due to Oxidative Stress Induced by Lead and Arsenic in Male Rats

Occupational and environmental exposure to heavy metals such as arsenic (As) and lead (Pb) by inducing oxidative damage may impair male fertility. However, there is a new view that shows that the nano form of vitamins such as vitamin C, which have antioxidant activity, can be effective in improving this disorder. Therefore, this study aimed to evaluate the effect of NVC (NVC) on reproductive toxicity caused by the combination of Pb and As on testicular histology, sperm morphology, oxidative stress parameters, and hormonal changes in male rats. In this experimental study, forty-two male Wistar rats were randomly divided into six groups: control, NVC (200 mg/kg), As (50 ppm sodium arsenate), Pb (500 ppm Pb acetate), As + NVC, and Pb + NVC. FSH, LH, and testosterone levels were measured in serum. The activity of glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT), carbonyl protein, malondialdehyde (MDA), and total antioxidant capacity (TAC) was measured in testis. Histological examination and sperm parameters were also evaluated. FSH, LH, and testosterone levels and sperm parameters significantly decreased, and levels of protein carbonyl, MDA, and DNA fragmentation increased in the As and Pb groups, while treatment with NVC could improve them. Histological evaluation and sperm parameters in As and Pb groups showed damage in the process of spermatogenesis and sperm parameters. The treatment with NVC could significantly improve these parameters. The activity of GPx, SOD, and CAT in testis decreased in As and Pb groups, while treatment with NVC could enhance them. It can be concluded that NVC by inhibiting oxidative damage and improving serum level of testosterone, LH, and FSH could overcome As- and Pb-induced reproductive dysfunction.

Soursop juice enhanced seminal antioxidant defence and semen quality of rabbit bucks in extremely dry climatic condition of Southwestern Nigeria

Heat induced stress associated with dry climatic conditions in the tropics does have adverse effects reproduction in rabbits, and this in-turn impacts negatively on the income of rabbit farmers. However, natural products might prove to be a reliable, safe and cheap remedy for ameliorating reproductive such anomalies in rabbits. The potential of soursop for mitigating heat induced reproductive deficiency in rabbit bucks was investigated during the peak of dry climatic conditions in southwestern Nigeria. Sixty mixed breed (New Zealand white x Chinchilla) adult rabbit bucks were allotted to five treatments of four replicates (3 bucks per replicate) each in a completely randomized design. Soursop (Annona muricata) fruit was processed into juice using standard procedures and was designated as soursop juice. The juice was administered orally daily per kg body weight (BW), 0.55ml/kgBW distilled water (control), 0.55 ml/kgBW soursop juice, 1.11 ml/kgBW soursop juice, 1.67 ml/kgBW soursop juice and 2.22 ml/kgBW soursop juice to designated treatments 1 to 5, respectively for 56 days. Semen samples were collected with an improvised artificial vagina on the 28th and 56th day of the study, semen quality and seminal oxidative status were evaluated using standard procedures. Results showed that rabbit buck exposed to heat stress had lower semen quality, seminal antioxidants and increased seminal lipid peroxidation. However, the consumption of soursop juice lowered lipid peroxidation and enhanced (p < 0.05) antioxidant production in the seminal fluid of heat-stressed bucks than bucks on control group. Bucks' semen quality and antioxidant status peaks in heat-stressed bucks gavaged 2.22 ml/kgBW soursop juice and gives 100% recovery from the effects of heat induced stress. It can be concluded that 2.22 ml/kgBW soursop juice administered for 56 days did enhance spermatozoa quality and mitigated lipid peroxidation by improving antioxidant capacity of male rabbits in a dose dependent manner on extremely dry climatic conditions.

Molecular toxicity of methotrexate in rheumatoid arthritis treatment: A novel perspective and therapeutic implications

Rheumatoid arthritis (RA) is an autoimmune inflammatory systematic complication which is a chronic disorder that severely affects bones and joints and results in the quality of life impairment. Methotrexate (MTX), an FDA-approved drug has maintained the standard of care for treating patients affected with RA. The mechanism of MTX includes the inhibition of purine and pyrimidine synthesis, suppression of polyamine accumulation, promotion of adenosine release, adhesion of the inflammatory molecules, and controlling of cytokine cascade in RA. The recommended dose for RA patients is 5-25 mg of MTX per week, depending on the severity of the disease but MTX has proven to be cytotoxic with side effects affecting various tissues when treating RA patients even with low doses over a prolonged period of time. The mechanism of such toxicity is not entirely understood. This review strives to understand it by correlating the different pathways, including MTX in folate metabolism, Sirt1/Nrf2/γ-gcs, and γ-gcs/CaSR-TNF-α/NF-kB signaling. In addition to this, the importance of targeted therapy combination with MTX on RA treatment and combinations approved from the clinical trials are also briefly discussed. Overall, this review elucidates the various MTX molecular mechanisms and toxicity at the molecular level, the limitations, and the scope for future directions.

Antioxidant enzymes and association of CAT SNP-21 A/T (rs7943316) with male infertility

Infertility is a multifactorial and polygenic disease. A vast majority of infertility is still unexplained despite modern diagnostic techniques. Oxidative stress is considered a factor for male infertility but etiology in terms of functional gene polymorphism and experimental studies on human subjects is scarcely reported. The aim of the study was to investigate the status of three antioxidant enzymes; catalase, superoxide dismutase (SOD), and glutathione reduced (GSH) in clinically diagnosed infertile males and find the potential association of CAT gene variant in the promoter region -21 A/T (rs7943316). The study consisted of 55 clinically diagnosed infertile males and 50 non-infertile volunteers. The activity of antioxidant enzymes was measured through a spectrophotometer. Polymerase chain reaction-restriction fragment length polymorphism was performed for genotyping of single-nucleotide polymorphism. Catalase enzyme activity was significantly decreased while SOD and GSH were substantially increased (p ≤ 0.01) in infertile men in comparison to non-infertile. CAT gene variant rs7943316 had shown significant association in dominant, recessive model and allelic frequencies. The study concludes that rs7943316 has a substantial role in male infertility. The outcome of the study may help in resolving idiopathic infertility cases and may help in evolving novel diagnostic and therapeutic approaches. Other variants of CAT and antioxidant genes are suggested to ascertain further insight.

Does Coenzyme Q10 Supplementation Improve Testicular Function and Spermatogenesis in Male Mice with Chronic Kidney Disease?

Simple Summary

Chronic kidney disease (CKD) is found to be linked to elevated apoptosis, oxidative stress and inflammation. Moreover, lower testosterone, poorer sperm quality and lower reproductive function have also been observed. Coenzyme Q10 (CoQ10), a widely used antioxidant involved in mitochondrial energy production, is indispensable for maintaining the efficient energy system of spermatozoa and protecting their membranes from lipid peroxidation, yet there are few studies focusing on the effects of CoQ10 on CKD-induced male infertility. This study suggests that CoQ10 increases testosterone levels and improves spermatogenesis in CKD mice.

Abstract

The aim of the study was to examine the potential effects of coenzyme Q10 (CoQ10) on reproductive function in a chronic kidney disease (CKD) mouse model. Nine-week-old mice were randomly assigned to two groups: sham surgery (n = 18) and CKD surgery (n = 18). After surgery, the study groups received CoQ10 (10 mg/kg body weight dissolved in corn oil by oral gavage) or corn oil as a vehicle daily for 8 weeks. The groups that underwent 5/6 nephrectomy developed significant elevations of serum BUN and creatinine levels. The CoQ10 treatment significantly increased the serum and testicular CoQ10 levels and alleviated the poor semen quality from incomplete spermatogenesis. The testosterone concentration, in addition to the protein expression of enzymes related to testosterone biosynthesis, was also elevated, and the CKD-induced decrease in antioxidant activity in the testes was significantly ameliorated. The results suggest that CoQ10 could act against CKD-induced testicular dysfunction through improvements in the sperm function, testicular morphology, testosterone levels and related biosynthesis pathways, in addition to antioxidant activity.

Mangiferin mitigates di-(2-ethylhexyl) phthalate-induced testicular injury in rats by modulating oxidative stress-mediated signals, inflammatory cascades, apoptotic pathways, and steroidogenesis

Di-(2-ethylhexyl) phthalate (DEHP) is an endocrine disruptor that causes reproductive defects in male animal models. This study was conducted to explore the plausible modulatory effects of mangiferin (MF) against DEHP-induced testicular injury in rats. Thirty-two adult male albino rats were allocated into four groups. Two groups were given DEHP (2 g/kg/day, p.o) for 14 days. One of these groups was treated with MF (20 mg/kg/day, i.p) for 7 days before and 14 days after DEHP administration. A vehicle-treated control was included, and another group of rats was given MF only. Results revealed that MF treatment suppressed oxidative testicular injury by amplifying the mRNA expression of nuclear factor-erythroid 2 related factor-2 (Nrf2) and increasing hemoxygenase-1 (HO-1), glutathione, and total antioxidant capacity (TAC) levels. This treatment also enhanced superoxide dismutase activity, but it decreased malondialdehyde and nitric oxide levels. MF had an anti-inflammatory characteristic, as demonstrated by the downregulation of the mRNA of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). The content of tumor necrosis factor-alpha also decreased. MF modulated the apoptotic pathway by suppressing the mRNA of cytochrome c (Cyt c), Fas ligand content, Bax IHC expression, caspase-3 activity and cleaved caspase-3 IHC expression. It also upregulated the expression levels of heat-shock protein 70 (HSP70) and B-cell lymphoma 2. Moreover, MF upregulated the mRNA expression levels of HSP70 and c-kit and enriched the content of steroidogenic acute regulatory (StAR) protein, which were reflected in serum testosterone levels. This result indicated that MF played crucial roles in steroidogenesis and spermatogenesis. Besides, the activities of testicular marker enzymes, namely, acid and alkaline phosphatases, and lactate dehydrogenase, significantly increased. Histopathological observations provided evidence supporting the biochemical and molecular measurements. In conclusion, MF provided protective mechanisms against the DEHP-mediated deterioration of testicular functions partially through its antioxidant, anti-inflammatory, and anti-apoptotic properties. It also involved the restoration of steroidogenesis and spermatogenesis through the modulation of Nrf2/HO-1, NF-κB/Cyt c/HSP70, and c-Kit signaling cascades.

Influences of the polymorphisms of the Sod2 gene (rs4880) on the motility and vigor of X- and Y-bearing sperm at different pH values

Superoxide dismutase 2 (SOD2) is an antioxidant enzyme that appears phylogenetically conserved. However, functional Sod2 polymorphisms have been studied, and the specific polymorphisms are related to activity alterations of the SOD2 enzyme. An example of a polymorphism of SOD2 is Val16Ala (rs4880), which has been identified in exon 2 of the human Sod2 gene. This polymorphism is recognized as a single nucleotide polymorphism (SNP) and alters the conformation of SOD2. Additionally, recent studies have shown that the Ala16 Val polymorphism in Sod2 can be related to different pathological diseases. In these terms, the objective of the present study was to evaluate whether the polymorphism of SOD2 in Val16Ala (rs4880) influences the motility and vigor of X- and Y-bearing sperm at different pH values promoting sperm selection. We found that polymorphism rs4880 at normal pH conditions can result in alterations in the activity of superoxide dismutase in the sperm through different assay analyses. Moreover, compelling modulation evidence indicates that this effect could also mediate seminal plasma redox alterations and consequently can play an important role in sperm physiology, fertilization, and postfertilization.

Correlation between sperm DNA fragmentation index and semen parameters in 418 men seen at a fertility center

Objective:

Methods:

Results:

Conclusions:

Can Nutrition Help in the Treatment of Infertility?

Infertility is defined as the inability to conceive after 12 months of unprotected intercourse or six months for women aged 35 years or older. The physical, emotional, psychological, and financial statuses of infertile couples are tremendously affected especially after undergoing diagnostic and/or curative treatments. Human fertility is influenced by multiple factors including female or male, and modifiable or non-modifiable factors. There is growing evidence that nutri-tion may play an important role in adjusting fertility-related outcomes in both men and women. The objective of our study was to summarize the latest data on nutritional factors (specific food groups, nutrients, and nutritional supplements) that have an impact on female or male sexual and reproductive function. PubMed and Google Scholar platforms were used to collect appropriate articles for the review using several combinations of keywords (infertility, diet, dietary supplements, antioxidants, and beverages). Adherence to a healthy dietary pattern favoring fish, poultry, whole grains, fruits, vegetables, and healthy fats, was related to better fertility in both genders. Despite the multifactorial etiology of sexual infertility, nutrition may affect the sexual/reproductive function in both women and men.

Assessment and Establishment of Correlation between Reactive Oxidation Species, Citric Acid, and Fructose Level in Infertile Male Individuals: A Machine-Learning Approach

Background:

Biochemical complexity of seminal plasma and obesity has an important role in male infertility (MI); so far, it has not been possible to provide evidence of clinical significance for all of them.

Aims:

Our goal here is to evaluate the correlation between biochemical markers with semen parameters, which might play a role in MI.

Study Setting and Design:

We enlisted 100 infertile men as patients and 50 fertile men as controls to evaluate the sperm parameters and biochemical markers in ascertaining MI.

Materials and Methods:

Semen analyses, seminal fructose, citric acid, and reactive oxidation species (ROS) were measured in 100 patients and 50 controls.

Statistical Analysis:

Descriptive statistics, an independent t-test, Pearson correlation, and machine-learning approaches were used to integrate the various biochemical and seminal parameters measured to quantify the inter-relatedness between these measurements.

Results:

Pearson correlation results showed a significant positive correlation between body mass index (BMI) and fructose levels. Citric acid had a positive correlation with sperm count, morphology, motility, and volume but displayed a negative correlation with BMI and basal metabolic rate (BMR). However, BMI and BMR had a positive correlation with ROS. Sperm count, morphology, and motility were negative correlations with ROS. The machine-learning approach detected that pH was the most critical parameter with an inverse effect on citric acid, and BMI and motility were the most critical parameter for ROS.

Conclusion:

We recommend that evaluation of biochemical markers of seminal fluid may benefit in understanding the etiology of MI based on the functionality of accessory glands and ROS levels.

Toxicity of carbon tetrachloride, free radicals and role of antioxidants

Several chemicals, including environmental toxicants and clinically useful drugs, cause severe cellular damage to different organs of our body through metabolic activation to highly reactive substances such as free radicals. Carbon tetrachloride is an organic compound of which chemical formula is CCl₄. CCl₄ is strong toxic in the kidney, testicle, brain, heart, lung, other tissues, and particularly in the liver. CCl₄ is a powerful hepatoxic, nephrotoxic and prooxidant agent which is widely used to induce hepatotoxicity in experimental animals and to create hepatocellular carcinoma, hepatic fibrosis/cirrhosis and liver injury, chemical hepatitis model, renal failure model, and nephrotoxicity model in recent years. The damage-causing mechanism of CCl₄ in tissues can be explained as oxidative damage caused by lipid peroxidation which starts after the conversion of CCl₄ to free radicals of highly toxic trichloromethyl radicals (•CCl₃) and trichloromethyl peroxyl radical (•CCl₃O₂) via cytochrome P450 enzyme. Complete disruption of lipids (i.e., peroxidation) is the hallmark of oxidative damage. Free radicals are structures that contain one or more unpaired electrons in atomic or molecular orbitals. These toxic free radicals induce a chain reaction and lipid peroxidation in membrane-like structures rich in phospholipids, such as mitochondria and endoplasmic reticulum. CCl₄-induced lipid peroxidation is the cause of oxidative stress, mitochondrial stress, endoplasmic reticulum stress. Free radicals trigger many biological processes, such as apoptosis, necrosis, ferroptosis and autophagy. Recent researches state that the way to reduce or eliminate these CCl₄-induced negative effects is the antioxidants originated from natural sources. For normal physiological function, there must be a balance between free radicals and antioxidants. If this balance is in favor of free radicals, various pathological conditions occur. Free radicals play a role in various pathological conditions including Pulmonary disease, ischemia / reperfusion rheumatological diseases, autoimmune disorders, cardiovascular diseases, cancer, kidney diseases, hypertension, eye diseases, neurological disorders, diabetes and aging. Free radicals are antagonized by antioxidants and quenched. Antioxidants do not only remove free radicals, but they also have anti-inflammatory, anti-allergic, antithrombotic, antiviral, and anti-carcinogenic activities. Antioxidants contain high phenol compounds and antioxidants have relatively low side effects compared to synthetic drugs. The antioxidants investigated in CCI₄ toxicity are usually antioxidants from plants and are promising because of their rich resources and low side effects. Data were investigated using PubMed, EBSCO, Embase, Web of Science, DOAJ, Scopus and Google Scholar, Carbon tetrachloride, carbon tetrachloride-induced toxicity, oxidative stress, and free radical keywords. This study aims to enlighten the damage-causing mechanism created by free radicals which are produced by CCl₄ on tissues/cells and to discuss the role of antioxidants in the prevention of tissue/cell damage. In the future, Antioxidants can be used as a therapeutic strategy to strengthen effective treatment against substances with high toxicity such as CCl₄ and increase the antioxidant capacity of cells.

Coenzyme Q10, oxidative stress markers, and sperm DNA damage in men with idiopathic oligoasthenoteratospermia

Objective

Oxidative stress (OS) plays a key role in the etiology of unexplained male infertility. Coenzyme Q10 (CoQ10) is a potent antioxidant that may improve semen quality and OS in infertile men with idiopathic oligoasthenoteratospermia (OAT), but the underlying mechanism is unknown. Therefore, the present study was undertaken to investigate the effect of CoQ10 on OS markers and sperm DNA damage in infertile patients with idiopathic OAT.

Methods

This prospective controlled study included 50 patients with idiopathic OAT and 50 fertile men who served as controls. All patients underwent a comprehensive medical assessment. Patients and controls received 200 mg of oral CoQ10 once daily for 3 months. Semen and blood were collected and analyzed for sperm parameters, seminal CoQ10 levels, reactive oxygen species (ROS) levels, total antioxidant capacity, catalase, sperm DNA fragmentation (SDF), and serum hormonal profile.

Results

The administration of CoQ10 to patients with idiopathic OAT significantly improved sperm quality and seminal antioxidant status and significantly reduced total ROS and SDF levels compared to pretreatment values.

Conclusion

CoQ10, at a dose of 200 mg/day for 3 months, may be a potential therapy for infertile patients with idiopathic OAT, as it improved sperm parameters and reduced OS and SDF in these patients.

Evaluation of the effect of vitamin D supplementation on spermatogram, seminal and serum levels of oxidative stress indices in asthenospermia infertile men: a study protocol for a triple-blind, randomized controlled trial

BACKGROUND

It is suggested that vitamin D may have a beneficial role in male reproduction. The male reproductive system is a target tissue for vitamin D. This study will aim to evaluate the effects of vitamin D supplementation on sperm parameters, seminal and serum levels of oxidative stress and serum endocrine factors in asthenospermia infertile men.

METHODS/DESIGN

This randomized, triple-blind, placebo-controlled clinical trial will be conducted on 86 infertile men with idiopathic asthenozoospermia (the mobility of sperm < 40% and rapid progressive sperm motility < 32%), with serum levels of vitamin D less than 30 ng / ml in the "Infertility Clinic of Ahvaz Jahad daneshgahi", Iran.

MAIN OUTCOMES MEASURE (S)

Demographic data, dietary intake, physical activity, sun exposure, anthropometric indices, serum and seminal levels of MDA (Malondialdehyde), 8-hydroxy-2- Dioxy Guanosine (8-OHDG), Total Antioxidant Capacity (TAC) and calcium, sperm DNA fragmentation index (DFI), serum 25-OHD, luteinizing hormone (LH), follicle-stimulating hormone (FSH), total testosterone (T), estradiol (E2), sex hormone-binding globulin (SHBG), free androgen index (FAI = T/SHBG. 100), T/LH and T/E2 ratios, prolactin (PRO), parathyroid hormone (PTH), osteocalcin (OCN), phosphorus and sperm parameters.

DISCUSSION

The deficiency of vitamin D as an antioxidant is common all over the world. Numerous observational studies have shown a positive association between vitamin D levels and semen quality. However, few clinical studies have been conducted in this area. So considering with the high prevalence of this antioxidant deficiency specifically in infertile men, it seems that the supplementation of vitamin D in infertile men with insufficient levels or deficiency may improve the status of oxidative stress and thereby may affect sperm parameters and endocrine factors involved in male fertility.

TRIAL REGISTRATION

Iran Clinical Trials Registry, ID: IRCT20151128025274N4 , registered on 28 March 2018.

Coenzyme Q10, oxidative stress, and male infertility: A review

Male infertility has a complex etiopathology, which mostly remains elusive. Although research has claimed that oxidative stress (OS) is the most likely underlying mechanism of idiopathic male infertility, the specific treatment of OS-mediated male infertility requires further investigation. Coenzyme Q10 (CoQ10), a vitamin-like substance, has been found in measurable levels in human semen. It exhibits essential metabolic and antioxidant functions, as well as playing a vital role in mitochondrial bioenergetics. Thus, CoQ10 may be a key player in the maintenance of biological redox balance. CoQ10 concentrations in seminal plasma directly correlate with semen parameters, especially sperm count and sperm motility. Seminal CoQ10 concentrations have been shown to be altered in various male infertility states, such as varicocele, asthenozoospermia, and medical or surgical regimens used to treat male infertility. These observations imply that CoQ10 plays an important physiological role in the maintenance and amelioration of semen quality. The present article thereby aimed to review the possible mechanisms through which CoQ10 plays a role in the regulation of male reproductive function, and to concisely discuss its efficacy as an ameliorative agent in restoring semen parameters in male infertility, as well as its impact on OS markers, sperm DNA fragmentation, pregnancy, and assisted reproductive technology outcomes.

Turmeric and vitamin C mitigate testicular atrophy induced by lead diacetate via regulation of GRP-78/17β-HSD pathways in rat's model

Occupational and ecological contacts to lead persist as a universal concern. Lead alters most of the physiological processes via enhancing oxidative stress. Thus, this study was purposed to assess the influence of turmeric (TMRC) and/or vitamin C (VIT-C) on Lead diacetate (Lead diAC)-induced testicular atrophy with an emphasis on oxidative stress, inflammation, BAX/STAR and GRP-78/17β-HSD signalling. Rats were injected with Lead diAC and then treated with TMRC and/or VIT-C orally for 1 week. Lead diAC decreased serum testosterone and testicular glutathione levels. It also decreased superoxide dismutase activity. On the contrary, levels of malondialdehyde, tumour necrosis factor-α, IL-1β and caspase-3 were increased. mRNA levels and protein expressions of GRP-78 and BAX were upregulated, while the expression of both steroidogenic acute regulatory protein and 17β-HSD were downregulated. DNA fragmentation was increased as well. These changes were further confirmed by histopathological findings. Supplementation with TMRC and/or VIT-C ameliorated all of the above parameters. In Conclusion: TMRC or VIT-C specially in combination group prevents Lead diAC testicular damage via reduction of oxidative injury as well as inflammation, downregulation of GRP-78/BAX and upregulation of 17β-HSD and STAR expression as well as improvement in the histological architecture of the testis.

Evaluation of Serum Selenium Status by Age and Gender: A Retrospective Observational Cohort Study in Western Romania

Selenium, residing in a series of selenoproteins, plays an important role in both female and male reproductive function. Of particular significance for reproduction is the antioxidant glutathione peroxidase (GPx), a main selenoenzyme, whose level is regulated by the availability of Se in the body. We hypothesized that changes in Se status, closely related to GPx activity, would result in an increased risk of reproductive dysfunction in individuals. We retrospectively investigated the serum selenium (SeS) concentrations of 1264 apparently healthy people, aged 16–89 years, from Western Romania. The general analysis revealed a non-normal SeS distribution with a median SeS of 100.26 ± 18.32 μg/L and a significant difference in SeS levels between age groups. The analysis of the young group (16–35 years) revealed that up to 50% of individuals did not reach the SeS threshold corresponding to maximum GPx activity (80 μg/L), and a significant imbalance between the genders was apparent when looking at SeS values outside the range. Our results correlated with the general diminished reproductive ability registered in Romania during the last few years. Serum selenium content proves to offer a proper reflection of the fertility competence of the young population, and its monitoring is important for guiding dietary adjustments and attaining normal reproductive function.

Comprehensive Transcriptome Analysis of mRNA Expression Patterns of Early Embryo Development in Goat under Hypoxic and Normoxic Conditions

Simple Summary

Oxygen plays a vital role in the development of early embryos, no matter whether it is too high or low, it will adversely affect the early embryo development, but the mechanisms involved in these effects are still unclear. RNA-seq was performed to compare 8-cell-stage and blastocyst-stage goat embryos under hypoxic and normoxic conditions, the mRNA expression mechanisms of 8-cell- and blastocyst-stage embryos were systematically analyzed under hypoxic and normoxic conditions. Functional enrichment analysis indicated that these differentially expressed genes (DEGs) were mainly related to biological processes and function regulation. In conclusion, we can infer that oxidative stress regulates early embryo development by affecting the expression of zygotic genes and transcription factors, and those stress genes play a potential role in adaptation to normoxic environments in goat embryos.

Abstract

It has been reported that hypoxic environments were more suitable for the in vitro development of mammalian embryos, but the underlying mechanisms were still unclear. In the present study, RNA-seq was performed to compare 8-cell-stage and blastocyst-stage goat embryos under hypoxic and normoxic conditions; zygotes were checked at 72 and 168 h to 8-cell stage (L8C) and blastocyst stage (LM) in hypoxic conditions and 8-cell stage (H8C) and blastocyst stage (HM) in normoxic conditions. In the H8C and L8C groups, 399 DEGs were identified, including 348 up- and 51 down-regulated DEGs. In the HM and LM groups, 1710 DEGs were identified, including 1516 up- and 194 down-regulated DEGs. The expression levels of zygotic genes, transcription factors, and maternal genes, such as WEE2, GDF9, HSP70.1, BTG4, and UBE2S showed significant changes. Functional enrichment analysis indicated that these DEGs were mainly related to biological processes and function regulation. In addition, combined with the pathway–gene interaction network and protein–protein interaction network, twenty-two of the hub genes were identified and they are mainly involved in energy metabolism, immune stress response, cell cycle, receptor binding, and signal transduction pathways. The present study provides comprehensive insights into the effects of oxidative stress on early embryo development in goats.

Effect of trace elements on the seminal oxidative status and correlation to sperm motility in infertile Saudi males

The impact of trace elements, especially zinc, selenium, copper, and magnesium, on male fertility has gained great interest and significance. Increased oxidative stress and altered trace element levels are probable etiological factors underlying male reproductive dysfunction and infertility. The present study focused on the evaluation of seminal oxidative markers, such as reactive oxygen species (ROS), malondialdehyde (MDA), and total antioxidant capacity (TAC), and trace element levels in the normozoospermic fertile control group (n = 40) and asthenozoospermic infertile group (n = 30). Semen from infertile men exhibited significantly higher ROS and MDA levels accompanied with significant decline in TAC and trace element (zinc and magnesium) levels. Furthermore, a significant correlation was observed between trace elements and oxidative markers with sperm motility. The current study revealed increased lipid peroxidation and oxidant-reductant imbalance that leads to deterioration of semen quality and male infertility. Thus, oxidative stress and trace elements can be considered important biomarkers of male infertility. Measurement of seminal oxidative stress with conventional seminological parameters must be integrated in fertility assessment from early stages to ensure healthy semen characteristics and fertility in men.

Semen evaluation: methodological advancements in sperm quality-specific fertility assessment - A review

Assessment of male fertility is based on the evaluation of sperm. Semen evaluation measures various sperm quality parameters as fertility indicators. However, semen evaluation has limitations, and it requires the advancement and application of strict quality control methods to interpret the results. This article reviews the recent advances in evaluating various sperm-specific quality characteristics and methodologies, with the help of different assays to assess sperm-fertility status. Sperm evaluation methods that include conventional microscopic methods, computer-assisted sperm analyzers (CASA), and flow cytometric analysis, provide precise information related to sperm morphology and function. Moreover, profiling fertility-related biomarkers in sperm or seminal plasma can be helpful in predicting fertility. Identification of different sperm proteins and diagnosis of DNA damage has positively contributed to the existing pool of knowledge about sperm physiology and molecular anomalies associated with different infertility issues in males. Advances in methods and sperm-specific evaluation has subsequently resulted in a better understanding of sperm biology that has improved the diagnosis and clinical management of male factor infertility. Accurate sperm evaluation is of paramount importance in the application of artificial insemination and assisted reproductive technology. However, no single test can precisely determine fertility; the selection of an appropriate test or a set of tests and parameters is required to accurately determine the fertility of specific animal species. Therefore, a need to further calibrate the CASA and advance the gene expression tests is recommended for faster and field-level applications.

Effect of prolonged whole-body hyperthermia on adult male rat testes and the protective role of vitamin C and E: A histological and biochemical study

Hyperthermia (HT) is a significant risk factor for male infertility. Most researchers investigated the effect of localized and short-term HT on male fertility. This study aimed to assess the harmful impacts of prolonged and generalized HT on testicular histology and ultrastructure in rats. The possible protective effects of vitamin E (Vit E), Vit C, and their combination were also investigated. Thirty male adult Wister rats were used (5 groups). 1- control, 2- HT, 3- Vit C, 4- Vit E, and 5- Vit C + Vit E. Rats in groups 2-5 were subjected to HT (41°C), 1 hr daily for 2 weeks. HT-induced a significant decrease in body weight gain, food and water intake, and serum testosterone. HT showed a damaging effect on the testicular and coda epididymis tissue. HT significantly (p ≤ .05) produced oxidative stress (decreased serum catalase (145.49 ± 8.98), glutathione peroxidase (20.27 ± 4.46), superoxide dismutase (2.68 ± 0.54), and reduced glutathione (5.18 ± 0.33), and increased malondialdehyde (9.46 ± 1.55). Vit E alone and combined with Vit C, significantly protected the gonads against the deleterious effects of HT. The results recommended that prolonged HT of the whole body is harmful to male fertility. Prophylactic therapy with Vit E could help decrease the HT-induced male gonadal harm.

Glutathione peroxidase 3 (extracellular isoform) levels and functional polymorphisms in fertile and infertile men

Background

Oxidative stress has an undeniable role in the impairment of sperm function and idiopathic male infertility. On the other hand, the local antioxidant system particularly glutathione peroxidase 3 (GPX3) as an extracellular enzyme protects male fertility from oxidative damages. Therefore, in the current study, we evaluated the association between two functional polymorphisms of the GPX3 gene with its levels in seminal fluid and subsequently with the risk of male infertility.

Result

We recruited 100 fertile and 100 infertile men for the study. Our results showed that the concentration of GPX3 was higher in the fertile group than infertile patients (p= <0.01), and there were positive correlations between GPX3 concentration in seminal fluid with sperm motility and morphology. The frequency of rs8177404 and rs3828599 genotypes and alleles was significantly different between the groups and we found that having the rs8177404 polymorphism (TC and CC genotypes) could increase the risk of idiopathic infertility more than 2-fold. On the other hand, the GG genotype (rs3828599) showed a protective effect against infertility. Our results demonstrated that men carrying CC genotype of rs8177404 polymorphism had significantly lower progressively motile sperm and higher immotile sperm compared with subjects carrying TT and TC genotypes. In the rs3828599 polymorphism, the GG carriers had significantly higher progressively motile and lower immotile sperm than AA carriers. Furthermore, men with genotypes of CC (rs8177404) and GG (rs3828599) had significantly lower and higher levels of GPX3 in the seminal fluid, respectively.

Conclusion

In conclusion, our results showed associations between sperm parameters with GPX3 levels and the gene polymorphisms. It seems rs8177404 and rs3828599 polymorphisms can affect GPX3 levels in seminal fluid and subsequently sperm parameters.

Ellagic acid improved diabetes mellitus-induced testicular damage and sperm abnormalities by activation of Nrf2

Diabetes mellitus induces testicular damage, increases sperm abnormalities, and impairs reproductive dysfunction due to induction of endocrine disturbance and testicular oxidative stress. This study evaluated the reproductive protective effect of ellagic acid (EA) against testicular damage and abnormalities in sperm parameters in Streptozotocin (STZ)-induced diabetic rats (T1DM) and examined some possible mechanisms of protection. Adult male rats were segregated into 5 groups (n = 12 rat/each) as control, control + EA (50 mg/kg/day), T1DM, T1DM + EA, and T1DM + EA + brusatol (an Nrf-2 inhibitor) (2 mg/twice/week). All treatments were conducted for 12 weeks, daily. EA preserved the structure of the seminiferous tubules, prevented the reduction in sperm count, motility, and viability, reduced sperm abnormalities, and downregulated testicular levels of cleaved caspase-3 and Bax in diabetic rats. In the control and diabetic rats, EA significantly increased the circulatory levels of testosterone, reduced serum levels of FSH and LH, and upregulated Bcl-2 and all steroidogenic genes (StAr, 3β-HSD1, and 11β-HSD1). Besides, it reduced levels of ROS and MDA but increased levels of GSH and MnSOD and the transactivation of Nrf2. All these biochemical alterations induced by EA were associated with increased activity and nuclear accumulation of Nrf2. However, all these effects afforded by EA were weakened in the presence of brusatol. In conclusion, EA could be an effective therapy to alleviated DM-induced reproductive toxicity and dysfunction in rats by a potent antioxidant potential mediated by the upregulation of Nrf2.

A Global Survey of Reproductive Specialists to Determine the Clinical Utility of Oxidative Stress Testing and Antioxidant Use in Male Infertility

Purpose

The use of antioxidants is common practice in the management of infertile patients. However, there are no established guidelines by professional societies on antioxidant use for male infertility.

Materials and Methods

Using an online survey, this study aimed to evaluate the practice pattern of reproductive specialists to determine the clinical utility of oxidative stress (OS) testing and antioxidant prescriptions to treat male infertility.

Results

Responses from 1,327 participants representing 6 continents, showed the largest participant representation being from Asia (46.8%). The majority of participants were attending physicians (59.6%), with 61.3% having more than 10 years of experience in the field of male infertility. Approximately two-thirds of clinicians (65.7%) participated in this survey did not order any diagnostic tests for OS. Sperm DNA fragmentation was the most common infertility test beyond a semen analysis that was prescribed to study oxidative stress-related dysfunctions (53.4%). OS was mainly tested in the presence of lifestyle risk factors (24.6%) or sperm abnormalities (16.3%). Interestingly, antioxidants were prescribed by 85.6% of clinicians, for a duration of 3 (43.7%) or 3–6 months (38.6%). A large variety of antioxidants and dietary supplements were prescribed, and scientific evidence were mostly considered to be modest to support their clinical use. Results were not influenced by the physician's age, geographic origin, experience or training in male infertility.

Conclusions

This study is the largest online survey performed to date on this topic and demonstrates 1) a worldwide understanding of the importance of this therapeutic option, and 2) a widely prevalent use of antioxidants to treat male infertility. Finally, the necessity of evidence-based clinical practice guidelines from professional societies is highlighted.

Impact of Coenzyme Q10 and Selenium on Seminal Fluid Parameters and Antioxidant Status in Men with Idiopathic Infertility

Oxidative stress (OS) is a key contributing factor in 30-80% of male infertility cases. To date, several antioxidant treatments have been put forth to manage OS-induced male infertility. This study intended to elucidate the impact of coenzyme Q10 (CoQ10) and selenium on seminal fluid parameters and antioxidant status in infertile men with idiopathic oligoasthenoteratospermia (OAT). In this prospective study, 70 patients with idiopathic OAT were randomly allocated to receive CoQ10 (200 mg/day) or selenium (200 μg/day) for 3 months. Semen quality parameters (following WHO guidelines, 5th edition), total antioxidant capacity (TAC), catalase (CAT), and superoxide dismutase (SOD) activities were compared before and after the treatment. The results of the study showed an increase in sperm concentration with CoQ10 treatment (p < 0.01) as well as increased progressive sperm motility (p < 0.01 and p < 0.05) and total sperm motility (p < 0.01 and p < 0.05) with CoQ10 and selenium treatment respectively. There was also a significant improvement in TAC (p < 0.01 and p < 0.05) and SOD (p < 0.01 and p < 0.05) following treatment with CoQ10 and selenium respectively while CAT improved only with CoQ10 therapy (p < 0.05). Sperm concentration, motility, and morphology also correlated significantly with TAC, SOD, and CAT (r = 0.37-0.76). In conclusion, treatment with CoQ10 (200 mg) or selenium (200 μg) could improve sperm concentration, motility, and antioxidant status in infertile men with idiopathic OAT with CoQ10 providing the higher improvement.

Dietary Antioxidants in the Treatment of Male Infertility: Counteracting Oxidative Stress

Infertility affects about 15% of the population and male factors only are responsible for ~25-30% of cases of infertility. Currently, the etiology of suboptimal semen quality is poorly understood, and many environmental and genetic factors, including oxidative stress, have been implicated. Oxidative stress is an imbalance between the production of free radicals, or reactive oxygen species (ROS), and the capacity of the body to counteract their harmful effects through neutralization by antioxidants. The purpose of this review, by employing the joint expertise of international researchers specialized in nutrition and male fertility areas, is to update the knowledge about the reproductive consequences of excessive ROS concentrations and oxidative stress on the semen quality and Assisted Reproduction Techniques (ART) clinical outcomes, to discuss the role of antioxidants in fertility outcomes, and finally to discuss why foods and dietary patterns are more innocuous long term solution for ameliorating oxidative stress and therefore semen quality results and ART fertility outcomes. Since this is a narrative review and not a systematic/meta-analysis, the summarized information in the present study should be considered cautiously.

Association between a marker of sperm DNA damage and sperm indices in infertile males in Benin City, Nigeria: A cross-sectional study

Background

Studies have shown oxidative DNA damage is associated with male infertility.

Objective

This study determines the levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and some markers of oxidative stress in seminal fluid of males investigated for infertility and men of proven fertility in Benin City, Nigeria.

Materials and Methods

Semen samples produced by self or assisted masturbation were analyzed by microscopic technique according to the World Health Organization guidelines. Thereafter, samples were centrifuged and seminal fluid plasma separated and stored at -20°C prior to assay for 8-OHdG and oxidative stress biomarkers. Based on the sperm concentration/count, the overall samples were grouped into the following categories: normospermia (n = 20), oligozoospermia (n = 30), and azoospermia (n = 20). The control group comprised of 30 age-matched males of proven fertility. The seminal fluid 8-OHdG, total antioxidant status, superoxide dismutase and malondialdehyde (MDA) were assayed through ELISA and spectrophotometric methods, respectively.

Results

Seminal plasma level of 8-OHdG and MDA were significantly higher (p = 0.01) in infertile subjects than controls. The mean levels of 8-OHdG and MDA in infertile subjects were higher in azoospermia than oligospermia than normospermia and so, was least in the normospermia. Conversely, the mean levels of total antioxidant status and superoxide dismutase were significantly lower (p = 0.01) in infertile than fertile the control male subjects with levels higher in normospermia than oligospermia and least in azoospermia. Moreover, the seminal 8-OHdG correlated negatively with sperm count (r = -0.359, p = 0.01), percent motility (r = -0.388, p = 0.04), and percent morphology (r = -0.327, p = 0.02).

Conclusion

The assessment of sperm DNA damage in addition to routine seminal fluid analysis may play an important role in specific diagnosis and management of male infertility.

Combining in vivo pathohistological and redox status analysis with in silico toxicogenomic study to explore the phthalates and bisphenol A mixture-induced testicular toxicity

The aim of this study was to: (i) determine and compare the capacity of bis (2 -ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), bisphenol A (BPA), and their mixture to produce testicular toxicity after the subacute exposure; (ii) explore the mechanisms behind the observed changes using in silico toxicogenomic approach. Male rats were randomly split into groups (n = 6): (1) Control (corn oil); (2) DEHP (50 mg/kg b.w./day); (3) DBP (50 mg/kg b.w./day); (4) BPA (25 mg/kg b.w./day); and (5) MIX (50 mg/kg b.w./day DEHP + 50 mg/kg b.w/day DBP + 25 mg/kg b.w./day BPA). Animals were sacrificed after 28 days of oral exposure, testes were extracted and prepared for histological assessments under the light microscope (haematoxylin and eosin staining) and redox status analysis. The Comparative Toxicogenomics Database (CTD; http://CTD.mdibl.org), Cytoscape software (https://cytoscape.org) and ToppGene Suite (https://toppgene.cchmc.org) were used for data-mining. Present pathohistological study has demonstrated more pronounced testicular toxicity of the MIX group (desquamated germinal epithelium cells, enlarged cells with hyperchromatic nuclei, multinucleated cell forms and intracytoplasmic vacuoles) in comparison with the single substances, while effects on redox status parameters were either more prominent, or present only in the MIX group. In silico investigation revealed 20 genes linked to male reproductive disorders, affected by all three investigated substances. Effects on metabolism, AhR pathway, apoptosis and oxidative stress could be singled out as the most probable mechanisms involved in the subacute DEHP, DBP and BPA mixture testicular toxicity, while the effect on oxidative stress parameters was confirmed by in vivo experiment.

Microplastics: A Threat for Male Fertility

Much of the planet is swimming in discarded plastic, which is harming animal and possibly human health. Once at sea, sunlight, wind, and wave action break down plastic waste into small particles: the microplastics (MPs). Currently, particular attention has been drawn to their effects on aquatic environments but the health risks, especially in mammals, are poorly known. These non-biodegradable materials can act as a vector for environmental pollutants, can be ingested by humans in food and water, and can enter and accumulate in human tissues with a possible risk for heath. Recent studies revealed the deleterious effects of MPs exposure in male reproduction and sperm quality, making them a potential hazard to reproductive success. This manuscript summarizes the main changes in sperm quality along the lifespan and the upcoming studies on the effects of MPs in male fertility in mammals.

Epidermal growth factor alleviates the negative impact of urea on frozen-thawed bovine sperm, but the subsequent developmental competence is compromised

Upon insemination, sperm cells are exposed to components of the female reproductive tract (FRT) fluids, such as urea and epidermal growth factor (EGF). It has been shown that both urea and EGF use EGF receptor signaling and produce reactive oxygen species (ROS) that are required at certain levels for sperm capacitation and acrosome reaction. We therefore hypothesized that during bovine sperm capacitation, a high level of urea and EGF could interfere with sperm function through overproduction of ROS. High-level urea (40 mg/dl urea is equal to 18.8 mg/dl of blood urea nitrogen) significantly increased ROS production and TUNEL-positive sperm (sperm DNA fragmentation, sDF) percentage, but decreased HOS test score, progressive motility, acrosome reaction and capacitation. The EGF reversed the negative effects of urea on all sperm parameters, with the exception of ROS production and DNA fragmentation, which were higher in urea-EGF-incubated sperm than in control-sperm. The developmental competence of oocytes inseminated with urea-EGF-incubated sperm was significantly reduced compared to the control. A close association of ROS production or sDF with 0-pronuclear and sperm non-capacitation rates was found in the network analysis. In conclusion, EGF enhanced urea-reduced sperm motility; however, it failed to reduce urea-increased sperm ROS or sDF levels and to enhance subsequent oocyte competence. The data suggests that any study to improve sperm quality should be followed by a follow-up assessment of the fertilization outcome.

Highly Cited Articles in the Field of Male Infertility and Antioxidants: A Scientometric Analysis

Purpose

The objective of this scientometric analysis was to recognize the top 100 cited articles on ‘Male infertility and Antioxidants’ and analyze its publication characteristics.

Materials and Methods

The Scopus database was used to retrieve related articles and the top 100 identified based on citation rate.

Results

The articles were published in 56 journals between 1995 and 2019 with a median (interquartile range) citation score of 17 (5–62). Among the top 100 articles, 69 were clinical studies, which included controlled and blinded (33.33%), prospective (27.54%), randomized-controlled trials (26.09%), uncontrolled (11.59%), and retrospective (1.45%) studies. In addition to conventional semen parameters, advanced sperm function tests such as oxidative stress (51%) and sperm DNA damage (23%) were reported. Pregnancy rate (33%) was found to be the most reported reproductive outcome. Antioxidant therapy was mostly investigated in male cohorts with sperm abnormalities such as asthenozoospermia (28%) and clinical conditions such as idiopathic male infertility (20%), varicocele/varicocelectomy (17%) and general male infertility (16%).

Conclusions

The most influential publications on antioxidants and male infertility were identified for the first time in the literature. This will serve as a reliable source of information for researchers and clinicians alike.

Voluntary exercise improves sperm parameters in high fat diet receiving rats through alteration in testicular oxidative stress, mir-34a/SIRT1/p53 and apoptosis

OBJECTIVES

High fat diet can lead to testicular structural and functional disturbances, spermatogenesis disorders as well as infertility. So, the present investigation was proposed to clarify whether voluntary exercise could prevent high fat diet induced reproductive complications in rats through testicular stress oxidative and apoptosis.

METHODS

Forty male Wistar rats were randomly divided into four groups; control (C), voluntary exercise (VE), high fat diet (HFD) and high fat diet and voluntary exercise (VE + HFD) groups. The rats in the VE and VE + HFD groups were accommodated in apart cages that had running wheels and the running distance was assessed daily for 10 weeks. In VE + HFD group, animals were fed with HFD for five weeks before commencing exercise. The sperm parameters, the expressions of testicular miR-34a gene, and P53 and SIRT1 proteins as well as testicular apoptosis were analyzed in all groups.

RESULTS

The results indicated that voluntary exercise in VE + HFD group led to significantly increased GPX and SOD activities, SIRT1 protein expression, sperm parameters, and decreased the expression of miR34a gene and Acp53 protein, and cellular apoptosis index compared to HFD group (p<0.001 to p<0.05). The SOD and catalase activities, SIRT1 protein expression, sperm parameters in VE + HFD group were lower than of those of VE group, however, MDA content, expression of Acp53 protein, apoptosis indexes in VE + HFD group was higher than that of VE group (p<0.001 to p<0.05).

CONCLUSION

This study revealed that voluntary exercise improved spermatogenesis, in part by decreasing the testicular oxidative stress status, apoptosis through alteration in miR-34a/SIRT1/p53 pathway.

APPLICATION EFFICIENCY OF BOVINE SERUM ALBUMIN FOR RECOVERY OF SEMINIFEROUS TUBULES OF TESTES AFTER CRYOPRESERVATION

An optimal approach to the recovery of testicular tissue fragments after cryopreservation is critical for their further use in order to successful fertility restoration. Aim. The purpose of this study was to investigate the effect of bovine serum albumin (BSA) addition to the rehabilitation medium on the morphofunctional characteristics of fragments of seminiferous tubules of testes (FSTT) of immature rats after cryopreservation. Methods. The object of the study was cryopreserved by slow cooling and vitrified FSTT. Warmed samples were incubated for 30 min in Leibovitz medium supplemented with BSA at concentrations of 0, 2, 5 or 10%. After that, morphological characteristics, the activity of the metabolic and antioxidant systems were evaluated. Results. It was found that in the samples cryopreserved by slow cooling, the use of 5% BSA contributed to the increase in the safety of spermatogenic epithelium cells, in the levels of metabolic and antioxidant activities. In case of vitrified FSTT samples, it was observed that the addition of 5% BSA to the medium promoted the repair of minor tissue damage and increased metabolic activity level, but did not affect the state of the antioxidant defense system. Conclusions. The obtained data can be used to develop an effective rehabilitation medium for cryopreserved fragments of the seminiferous tubules of testes using BSA.

Organopesticides and fertility: where does the link lead to?

Organopesticides (OPs) are a group of various synthetic chemicals prevalently used in agriculture and homestead plantations. OPs were originally developed to remove insects, weeds, and other pests from agricultural fields for improving crop yields. Modern pesticides including organochlorine pesticides, organophosphorus pesticides, and amido-formyl ester are closely related to our lives. Many people are exposed to various OPs during farming practice. OPs can cause adverse effects and provoke serious impacts on normal reproductive functions of humans, resulting in loss of fertility. The effects of OPs in the reproductive system include association with fluctuation in the levels of sex hormones, delayed menstrual cycle, ovarian dysfunction, alteration in ovary weight, changes of follicle growth, altered oocyte feasibility, and changed the quality of spermatogenesis. Current literature clearly states that exposure to various OPs can impair the fertility of women and cause a high risk of reproductive potential. However, investigations on OPs exposure to woman fertility remain scarce. This review highlights effects of exposure to OPs on the fertility of occupational women and mechanisms of action involved in such effects on the reproductive function of women along with their related impacts.

The Effect of Daily Intake of Selenium, Vitamin E and Folic Acid on Sperm Parameters in Males with Idiopathic Infertility: A Single-Blind Randomized Controlled Clinical Trial

Background

Male infertility may originate from a wide spectrum of conditions while in 30-40 percent of cases, no significant reason can be identified. Thereby, it is recognized as male idiopathic infertility. This study was undertaken to investigate the effect of daily intake of selenium, vitamin E and folic acid on sperm parameters in males with idiopathic infertility.

Materials and Methods

Seventy infertile men were selected to participate in this single-blind, randomized controlled clinical trial using convenience sampling. They were equally divided into two groups via permuted block randomization method. The intervention group received selenium tablet (200 μg per day, oral), vitamin E capsule (400 IU per day, oral) and folic acid tablet (5 mg per day, oral).The placebo group received matching placebo for three months. Semen volume, total sperm motility, sperm concentration, progressive sperm motility, normal sperm morphology, sperm motility index (SMI) and functional sperm concentration (FSC) were assessed by sperm quality analyzer-v (SQAV) before and after the intervention. Paired t test, and independent t test were used to compare the results within and between the groups, respectively. The IBM SPSS V.16.005 was used for data analysis. A P<0.05 was considered statistically significant.

Results

After three months, according to within-group analysis, a significant difference was found in mean SMI (P=0.007) and FSC (P=0.001) in the intervention group. According to between-group analysis, no significant difference was found in mean semen volume (P=0.610), sperm concentration (P=0.126), total sperm motility (P=0.765), progressive sperm motility (P=0.767), normal sperm morph (P=0.403), SMI (P=0.556) or FSC (P=0.706) between the groups.

Conclusion

Consumption of selenium, vitamin E and folic acid in infertile men with asthenozoospermia was not effective (Registration number: IRCT2017012432153N1).

Multiparametric Study of Antioxidant Effect on Ram Sperm Cryopreservation-From Field Trials to Research Bench

Simple Summary

The use of antioxidant compounds could be a successful tool to improve sperm cryopreservation protocols in ovine species. These molecules have been widely employed in different mammalian species with this purpose. It is important to consider the existence of a species-specific antioxidant effect discarding the extrapolations from other animal species. To corroborate the real effectiveness of these compounds is important to combine two approaches: in vitro sperm quality analyses and in vivo field trials based on fertility. In the first scenario, a multiparametric analyses and novel tests based on spermatozoa redox balance, as the main target of antioxidants, could improve the accuracy on antioxidant effectiveness on sperm quality. Moreover, an extensive field insemination study provides the definitive tool to select the best antioxidant treatment. All these aspects have been applied and extensively discussed throughout this manuscript. Novel approaches have been incorporated, such as RedoxSYS, to provide more accuracy in the integrative studies of Redox status in spermatozoa. The effectiveness of an antioxidant treatment, as trolox in our study, should be demonstrated in an integrative way, from in vivo (fertility trials) to in vitro analyses (sperm quality assays), especially when the final aim is to reach AI implementation.

Abstract

The optimization of sperm cryopreservation protocols in ram is a feasible tool to reinforce artificial insemination technologies considering the desirable application of sperm by vaginal/cervical or transcervical deposition. Cryopreservation provokes different types of damage on spermatozoa and many of these detrimental effects are triggered by redox deregulation. For this reason, the antioxidant supplementation in sperm cryopreservation protocols to decrease reactive oxygen species (ROS) levels and to equilibrate redox status has been widely employed in different species. Despite this, more fertility trials are necessary to provide the definitive tool to ensure the antioxidant effectiveness on sperm quality. For this reason, in this work, we performed a multiparametric analysis of some previously tested antioxidants (crocin, GSH and Trolox) on ram sperm cryopreservation from field trials to sperm quality analyses focused on new strategies to measure redox balance. Attending to fertility trial, Trolox supplementation registered an improvement concerning to fertility (when we considered high fertility males) and multiple lambing frequency and other complementary and descriptive data related to lambing performance such as prolificacy and fecundity. This positive effect was more evident in multiple lambing frequency when we considered low fertility males than in global male analysis. In vitro analyses of sperm quality confirmed in vivo trials registering a positive effect on sperm viability and redox balance. In this study, we provided the definitive evidence that the role of trolox on redox balance maintenance has a direct effect on fertility parameters, such as prolificacy. The effectiveness of antioxidant treatments was tested, for the first time in ovine species, using an integrative and multiparametric approach combining in vivo and in vitro analyses and novel approaches, such as RedoxSYS. These types of strategies should be applied to improve sperm conservation methods and optimize AI technologies upgrading the correlation between in vitro and in vivo analyses.