The incriminating role of reactive oxygen species in idiopathic male infertility: an evidence based evaluation

Omega-3 polyunsaturated fatty acids and its metabolite 12-HEPE rescue busulfan disrupted spermatogenesis via target to GPR120

Busulfan is an antineoplastic, which is always accompanied with the abnormal of spermatogonia self-renewal and differentiation. It has been demonstrated that the omega-3 polyunsaturated fatty acids (PUFAs) benefits mature spermatozoa. However, whether omega-3 can protect endogenous spermatogonia and the detailed mechanisms are still unclear. Evaluate of spermatogenesis function (in vivo) were examined by histopathological analysis, immunofluorescence staining, and western blotting. The levels of lipid metabolites in testicular tissue were determined via liquid chromatography. We investigated the effect of lipid metabolites on Sertoli cells provided paracrine factors to regulate spermatogonia proliferation and differentiation using co-culture system. In our study, we showed that omega-3 PUFAs significantly improved the process of sperm production and elevated the quantity of both undifferentiated Lin28+ spermatogonia and differentiated c-kit+ spermatogonia in a mouse model where spermatogenic function was disrupted by busulfan. Mass spectrometry revealed an increase in the levels of several omega-3 metabolites in the testes of mice fed with omega-3 PUFAs. The eicosapentaenoic acid metabolite 12-hydroxyeicosapentaenoic acid (12-HEPE) up-regulated bone morphogenic protein 4 (BMP4) expression through GPR120-ERK1/2 pathway activation in Sertoli cells and restored spermatogonia proliferation and differentiation. Our study provides evidence that omega-3 PUFAs metabolite 12-HEPE effectively protects spermatogonia and reveals that GPR120 might be a tractable pharmacological target for fertility in men received chemotherapy or severe spermatogenesis dysfunction.

Identification of hub genes associated with spermatogenesis by bioinformatics analysis

Spermatogenesis is a complex process related to male infertility. Till now, the critical genes and specific mechanisms have not been elucidated clearly. Our objective was to determine the hub genes that play a crucial role in spermatogenesis by analyzing the differentially expressed genes (DEGs) present in non-obstructive azoospermia (NOA) compared to OA and normal samples using bioinformatics analysis. Four datasets, namely GSE45885, GSE45887, GSE9210 and GSE145467 were used. Functional enrichment analyses were performed on the DEGs. Hub genes were identified based on protein-protein interactions between DEGs. The expression of the hub genes was further examined in the testicular germ cell tumors from the TCGA by the GEPIA and validated by qRT-PCR in the testes of lipopolysaccharide-induced acute orchitis mice with impaired spermatogenesis. A total of 203 DEGs including 34 up-regulated and 169 down-regulated were identified. Functional enrichment analysis showed DEGs were mainly involved in microtubule motility, the process of cell growth and protein transport. PRM2, TEKT2, FSCN3, UBQLN3, SPATS1 and GTSF1L were identified and validated as hub genes for spermatogenesis. Three of them (PRM2, FSCN3 and TEKT2) were significantly down-regulated in the testicular germ cell tumors and their methylation levels were associated with the pathogenesis. In summary, the hub genes identified may be related to spermatogenesis and may act as potential therapeutic targets for NOA and testicular germ cell tumors.

Oxido-Reduction Potential as a Method to Determine Oxidative Stress in Semen Samples

There are different estimates for the incidence of infertility. Its occurrence may vary from area to area, but on average, it affects 15% of couples and 10-12% of men worldwide. Many aspects of infertility can be linked to reactive oxygen species (ROS) and the process of oxidative stress (OS). The association between poor semen quality and OS is well known. Unfortunately, there is no accepted protocol for the diagnosis and treatment of OS in andrology. Oxido-reduction potential (ORP) measurement is a new method for determining the ratio between oxidant and antioxidant molecules. Currently, ORP measurement is one of the fastest and most user-friendly methods of andrological OS determination and our goals were to confirm published correlations between ORP values and sperm parameters, examine how sperm concentration influences these results, and investigate whether intracellular ROS formations are also manifested in the ORP values or not after artificial ROS induction. Intracellular ROS formations were induced by menadione (superoxide anion inducer), hydrogen peroxide, and tert-butyl hydroperoxide (lipid peroxidation inducer) treatments; sperm parameters like motility and viability were determined with an SCA Scope system, and ORP changes were recorded by the Mioxsys system. Significant correlations were noticed among the ORP, spermatozoa concentration, motility, progressive motility, and viability. Nevertheless, only the ORP value after normalization with the sperm count correlated with these parameters. Due to normalization, very low and very high sperm concentrations can give misleading results. The means of the non-normalized ORP values were almost the same. All of the applied treatments resulted in decreases in the viability, motility, and progressive motility, and interestingly, altered ORP levels were detected. In addition, it was determined that seminal plasma had a significant protective effect on spermatozoa. The elimination of seminal plasma caused higher sensitivity of spermatozoa against used OS inducers, and higher ORP levels and decreased viabilities and motilities were measured. The ORP level could be a good indicator of male OS; however, in cases of low and high sperm counts, its result can be misleading. Overall, the conclusion can be drawn that ORP determination is a suitable method for detecting intracellular ROS accumulation, but it has limitations that still need to be clarified.

The Protective Effects of Trametes Versicolor on Arsenic-Induced Male Reproductive Toxicity through Regulation of Oxidative Stress: A Biochemical and Histopathological Survey

Exposure to arsenic is linked to a wide range of diseases, in particular male reproductive toxicities. Trametes versicolor is a traditional medicinal fungus with a remarkable potential for antioxidant activity. The purpose of this study was to examine the ameliorating effects of water and methanol extracts of T. versicolor on arsenic-induced male reproductive toxicities via the abrogation of oxidative stress. The mice were divided as follows: control: normal saline, As: arsenic (15 mg/kg), WE: water extract (400 mg/kg), ME: methanol extract (400 mg/kg), As + WE: arsenic (15 mg/kg) + water extract (100, 200, 400 mg/kg), As + ME: arsenic (15 mg/kg) + methanol extract (100, 200, 400 mg/kg), and positive control: arsenic (15 mg/kg) + vitamin C (500 mg/kg). Animals were treated via the intraperitoneal route. About 24 hr later, the mice were euthanized, and oxidative stress parameters (reactive oxygen species [ROS], lipid peroxidation, glutathione concentration, protein carbonylation, glutathione peroxidase, and superoxide dismutase activity), histopathological changes and sperm parameters (count, motility, and morphology) were examined in the testicular tissue. Arsenic caused significant pathological changes in the testicular tissue and sperm morphology and significantly reduced sperm count and motility. Moreover, arsenic mediated oxidative stress via significant increases in ROS generation, lipid peroxidation, and protein carbonyl content, as well as significant depletion in glutathione concentration and superoxide dismutase and glutathione peroxidase activities. Although, coadministration of water and methanol extracts of T. versicolor at 200 and 400 mg/kg counteracted arsenic-induced oxidative and histopathological damages and improved sperm parameters. Our study indicated that T. versicolor ameliorated arsenic-induced testis toxicity and sperm dysfunction via attenuation of oxidative damage.

Selenium nanoparticles improve nickel-induced testosterone synthesis disturbance by down-regulating miR-708-5p/p38 MAPK pathway in Leydig cells

The present study was designed to investigate the role of miR-708-5p/p38 mitogen-activated protein kinase (MAPK) pathway during the mechanism of selenium nanoparticles (Nano-Se) against nickel (Ni)-induced testosterone synthesis disorder in rat Leydig cells. We conducted all procedures based on in vitro culture of rat primary Leydig cells. After treating Leydig cells with Nano-Se and NiSO₄ alone or in combination for 24 h, we determined the cell viability, reactive oxygen species (ROS) levels, testosterone production, and the protein expression of key enzymes involved in testosterone biosynthesis: steroidogenic acute regulatory (StAR) and cytochrome P450 cholesterol side chain cleavage enzyme (CYP11A1). The results indicated that Nano-Se antagonized cytotoxicity and eliminated ROS generation induced by NiSO₄ , suppressed p38 MAPK protein phosphorylation and reduced miR-708-5p expression. Importantly, we found that Nano-Se upregulated the expression of testosterone synthase and increased testosterone production in Leydig cells. Furthermore, we investigated the effects of p38 MAPK and miR-708-5p using their specific inhibitor during Nano-Se against Ni-induced testosterone synthesis disorder. The results showed that Ni-inhibited testosterone secretion was alleviated by Nano-Se co-treatment with p38 MAPK specific inhibitor SB203580 and miR-708-5p inhibitor, respectively. In conclusion, these findings suggested Nano-Se could inhibit miR-708-5p/p38 MAPK pathway, and up-regulate the key enzymes protein expression for testosterone synthesis, thereby antagonizing Ni-induced disorder of testosterone synthesis in Leydig cells.

Serum interleukin-38 and -41 levels as candidate biomarkers in male infertility

BACKGROUND

Interleukin (IL)-38 and IL-41 are novel cytokines, but their role in male infertility (MI) is unknown. The purpose of this study was to measure the levels of serum IL-38 and IL-41 in patients with MI and correlate these levels with semen indexes.

METHODS

Eighty-two patients with MI and 45 healthy controls (HC) were recruited for this study. Semen parameters were detected using computer-aided sperm analysis, Papanicolaou staining, ELISA, flow cytometry, peroxidase staining and enzyme methods. Serum IL-38 and IL-41 levels were determined by ELISA.

RESULTS

Serum IL-38 levels were decreased (P < 0.01) in patients with MI compared with HC. Serum IL-41 levels were significantly higher in patients with MI than in HC (P < 0.0001). In patients with MI, serum IL-38 levels were positively correlated with semen white blood cell counts (r = 0.29, P = 0.009), and there was a positive correlation between semen white blood cell counts and sperm concentration (r = 0.28, P = 0.0100) and seminal plasma elastase (r = 0.67, P < 0.0001). Receiver operating characteristic curve analysis showed that the area under the curve of IL-38 for diagnosing MI was 0.5637 (P > 0.05), and the area under the curve of IL-41 for diagnosing MI was 0.7646 (P < 0.0001).

CONCLUSIONS

Serum IL-38 levels were significantly lower, and serum IL-41 levels were higher in patients with MI. These results suggest that IL-38 and IL-41 may be novel biomarkers for the diagnosis of MI.

The therapeutic effect of co-administration of pentoxifylline and zinc in men with idiopathic infertility

Pentoxifylline is a derivative of methylxanthine that affects sperm motility. Also, zinc is an antioxidant that is involved in the activation of antioxidant enzymes. This study aimed to evaluate the effect of co-administration of pentoxifylline, and zinc in men with idiopathic infertility. In the present study, men with idiopathic infertility were identified and randomly divided into four groups: pentoxifylline, zinc, pentoxifylline + zinc, and placebo. According to the grouping, the patients received pentoxifylline and zinc for 3 months. Then, sperm parameters, biochemical factors, reproductive hormones, inflammatory factors, and DNA damage were evaluated before and after intervention. Data analysis was performed using SPSS software. Pentoxifylline and zinc were significantly effective in improving biochemical parameters, inflammatory factors, concentration, and motility of sperm. Pentoxifylline did not affect sperm morphology and reproductive hormones. However, in the zinc and zinc + pentoxifylline groups, a significant increase in normal morphology and reproductive hormones was observed. In the pentoxifylline group, sperm DNA fragmentation increased significantly, while in the zinc and zinc + pentoxifylline group, DNA fragmentation reduced significantly. Because of the role of zinc in protecting sperm chromatin, it is recommended that zinc and pentoxifyllinebe prescribed simultaneously. Clinical trial code: NCT05156684.

Effect of dietary phenylalanine on growth performance and intestinal health of triploid rainbow trout (Oncorhynchus mykiss) in low fishmeal diets

This study aimed to investigate the effects of phenylalanine on the growth, digestive capacity, antioxidant capability, and intestinal health of triploid rainbow trout (Oncorhynchus mykiss) fed a low fish meal diet (15%). Five isonitrogenous and isoenergetic diets with different dietary phenylalanine levels (1.82, 2.03, 2.29, 2.64, and 3.01%) were fed to triplicate groups of 20 fish (initial mean body weight of 36.76 ± 3.13 g). The weight gain rate and specific growth rate were significantly lower (p < 0.05) in the 3.01% group. The trypsin activity in the 2.03% group was significantly higher than that in the control group (p < 0.05). Amylase activity peaked in the 2.64% treatment group. Serum superoxide dismutase, catalase, and lysozyme had the highest values in the 2.03% treatment group. Liver superoxide dismutase and catalase reached their maximum values in the 2.03% treatment group, and lysozyme had the highest value in the 2.29% treatment group. Malondialdehyde levels in both the liver and serum were at their lowest in the 2.29% treatment group. Interleukin factors IL-1β and IL-6 both reached a minimum in the 2.03% group and were significantly lower than in the control group, while IL-10 reached a maximum in the 2.03% group (p < 0.05). The tight junction protein-related genes occludin, claudin-1, and ZO-1 all attained their highest levels in the 2.03% treatment group and were significantly higher compared to the control group (p < 0.05). The intestinal villi length and muscle layer thickness were also improved in the 2.03% group (p < 0.05). In conclusion, dietary phenylalanine effectively improved the growth, digestion, absorption capacity, antioxidant capacity, and intestinal health of O. mykiss. Using a quadratic curve model analysis based on WGR, the dietary phenylalanine requirement of triploid O. mykiss fed a low fish meal diet (15%) was 2.13%.

Semen rheology and its relation to male infertility

Infertility affects 15% of couples of reproductive age worldwide. In spite of many advances in understanding and treating male infertility, there is still a number of issues that need further investigation and translation to the clinic. Here, we review the current knowledge and practice concerning semen rheology and its relation with pathological states affecting male infertility. Although it is well recognized that altered rheological properties of semen can impair normal sperm movement in the female reproductive tract, routine semen analysis is mostly focused on number, motility and morphology of spermatozoa, and includes only an approximate, operator-dependent measure of semen viscosity. The latter is based on the possible formation of a liquid thread from a pipette where a semen sample has been aspirated, a method that is sensitive not only to viscosity but also to elongational properties and surface tension of semen. The formation of a liquid thread is usually associated with a gel-like consistency of the sample and changes in spermatozoa motility in such a complex medium are still to be fully elucidated. The aim of this review is to point out that a more quantitative and reliable characterization of semen rheology is in order to improve the current methods of semen analysis and to develop additional tools for the diagnosis and treatment of male infertility.

Motility Assessment of Ram Spermatozoa

For successful fertilisation to occur, spermatozoa need to successfully migrate through the female reproductive tract and penetrate the oocyte. Predictably, poor sperm motility has been associated with low rates of fertilisation in many mammalian species, including the ram. As such, motility is one of the most important parameters used for in vitro evaluation of ram sperm quality and function. This review aims to outline the mechanical and energetic processes which underpin sperm motility, describe changes in motility which occur as a result of differences in sperm structure and the surrounding microenvironment, and assess the effectiveness of the various methods used to assess sperm motility in rams. Methods of subjective motility estimation are convenient, inexpensive methods widely used in the livestock industries, however, the subjective nature of these methods can make them unreliable. Computer-assisted sperm analysis (CASA) technology accurately and objectively measures sperm motility via two-dimensional tracing of sperm head motion, making it a popular method for sperm quality assurance in domesticated animal production laboratories. Newly developed methods of motility assessment including flagellar tracing, three-dimensional sperm tracing, in vivo motility assessment, and molecular assays which quantify motility-associated biomarkers, enable analysis of a new range of sperm motion parameters with the potential to reveal new mechanistic insights and improve ram semen assessment. Experimental application of these technologies is required to fully understand their potential to improve semen quality assessment and prediction of reproductive success in ovine artificial breeding programs.

Overview of biological effects of melatonin on testis: A review

Infertility is a major global health issue and male factors account for half of all infertility cases. One of the causes of male infertility is the loss of spermatogonial stem cells, which may occur because of chemotherapy, radiotherapy or genetic defects. In numerous animal species, the evidence suggests the pineal gland and melatonin secretion in their reproductive activities are involved. Recently, considerable attention has pointed to the usage of melatonin in the treatment of diseases. Melatonin is associated with the regulation of circadian and seasonal rhythmic functions, immune system functions, retinal physiology, spermatogenesis and inhibition of tumour growth in different species. Several studies demonstrated that melatonin acts as an anti-apoptotic, anti-inflammatory, anticancer and antioxidant agent. Melatonin can also protect testicles and spermatogonia against oxidative damage, chemotherapy drugs, environmental radiation, toxic substances, hyperthermia, ischemia/reperfusion, diabetes-induced testicular damage, metal-induced testicular toxicity, improve sperm quality and it affects the testosterone secretion pathway by affecting Leydig cells. Therefore, the objective of this study is to investigate the biological effects of melatonin as a natural antioxidant on testicles and their disorders.

Mitochondria-Targeted Compounds to Assess and Improve Human Sperm Function

Significance: Currently 10%-15% of couples in reproductive age face infertility issues. More importantly, male factor contributes to 50% of these cases (either alone or in combination with female causes). Among various reasons, impaired sperm function is the main cause for male infertility. Furthermore, mitochondrial dysfunction and oxidative stress due to increased reactive oxygen species (ROS) production, particularly of mitochondrial origin, are believed to be the main contributors. Recent Advances: Mitochondrial dysfunction, particularly due to increased ROS production, has often been linked to impaired sperm function/quality. For decades, different methods and approaches have been developed to assess mitochondrial features that might correlate with sperm functionality. This connection is now completely accepted, with mitochondrial functionality assessment used more commonly as a readout of sperm functionality. More recently, mitochondria-targeted compounds are on the frontline for both assessment and therapeutic approaches. Critical Issues: In this review, we summarize the current methods for assessing key mitochondrial parameters known to reflect sperm quality as well as therapeutic strategies using mitochondria-targeted antioxidants aiming to improve sperm function in various situations, particularly after sperm cryopreservation. Future Directions: Although more systematic research is needed, mitochondria-targeted compounds definitely represent a promising tool to assess as well as to protect and improve sperm function. Antioxid. Redox Signal. 37, 451-480.

Glycerophospholipids protect stallion spermatozoa from oxidative damage in vitro

Stallion sperm membranes comprise a high proportion of polyunsaturated fatty acids, making stallion spermatozoa especially vulnerable to peroxidative damage from reactive oxygen species generated as a by-product of cell metabolism. Membrane lipid replacement therapy with glycerophospholipid (GPL) mixtures has been shown to reduce oxidative damage in vitro and in vivo. The aims of this study were to test the effects of a commercial preparation of GPL, NTFactor^® Lipids, on stallion spermatozoa under oxidative stress. When oxidative damage was induced by the addition of arachidonic acid to stallion spermatozoa, the subsequent addition of GPL reduced the percentage of 4-hydroxynonenal (4-HNE; a key end product of lipid peroxidation) positive cells (32.9 ± 2.7 vs 20.9 ± 2.3%; P ≤ 0.05) and increased the concentration of 4-HNE within the spent media (0.026 ± 0.003 vs 0.039 ± 0.004 µg/mL; P ≤ 0.001), suggesting that oxidized lipids had been replaced by exogenous GPL. Lipid replacement improved several motility parameters (total motility: 2.0 ± 1.0 vs 68.8 ± 2.9%; progressive motility: 0 ± 0 vs 19.3 ± 2.6%; straight line velocity: 9.5 ± 2.1 vs 50.9 ± 4.1 µm/s; curvilinear velocity: 40.8 ± 10 vs 160.7 ± 7.8 µm/s; average path velocity: 13.4 ± 2.9 vs 81.9 ± 5.9 µm/s; P ≤ 0.001), sperm viability (13.5 ± 2.9 vs 80.2 ± 1.6%; P ≤ 0.001) and reduced mitochondrial ROS generation (98.2 ± 0.6 vs 74.8 ± 6.1%; P ≤ 0.001). Supplementation with GPL during 17°C in vitro sperm storage over 72 h improved sperm viability (66.4 ± 2.6 vs 78.1 ± 2.9%; P ≤ 0.01) and total motility (53 ± 5.6 vs 66.3 ± 3.5%; P ≤ 0.05). It is concluded that incubation of stallion spermatozoa with sub-µm-sized GPL micelles results in the incorporation of exogenous GPL into sperm membranes, diminishing lipid peroxidation and improving sperm quality in vitro.

Ulva lactuca methanolic extract improves oxidative stress-related male infertility induced in experimental animals

AIM

This study designated to investigate and compare the therapeutic effect of Ulva lactuca methanolic extract against oxidative stress (OS)-infertility induced by naturally occurring prooxidants (gossypol) and selenium- vitamins A, C, and E (selenium-ACE) drug.

METHODS

Male infertility was induced in rat by intraperitoneal injection of 5 mg/kg gossypol eight times then the treatment was carried out with 100 mg/kg ulva methanolic extract oral administration for one or two weeks, after this period OS, and male infertile markers were detected in blood and/or testes.

RESULTS

Gossypol stimulated male infertility by increasing testicular OS markers and decreasing semen quality, hyaluronidase enzyme activity, and blood testosterone level. The treatment with ulva methanolic extract improved gossypol related adverse effects. The treatment period for two weeks with extract was the most potent one.

CONCLUSIONS

Ulva methanolic extract could be considered as good antioxidant therapeutic candidate for OS linked male infertility.

The cryoprotective effect of vitamins on human spermatozoa quality: a systematic review and meta-analysis

The Cryopreservation of spermatozoa ensures preserving fertility potential after some medical treatments such as chemotherapy and radiotherapy in cancer patients. However, many spermatozoa encounter serious damages, and their motility and viability decrease considerably after thawing. The excessive production of reactive oxygen species is one of the major causes of these damages. The supplementation of cryopreservation media with vitamins, which are well-known antioxidants, can reduce cryopreservation-induced damages. In this systematic review, we aimed to evaluate the cryoprotective effect of various vitamins on the quality of cryopreserved-thawed human spermatozoa. Two researchers searched PubMed, ISI, and Scopus databases up to March 2020. All original articles using vitamins in human spermatozoa cryopreservation media were included. We used a standardized form to extract sample size and to determine sample quality, the type and dose of vitamins, and the cryopreservation methods and their effects. We performed a meta-analysis on studies with available data (Mean + SD in cryoprotectant and cryoprotectant + cryoprotectant groups). We also performed a test of between-study heterogeneity, subgroup analysis, and meta-regression. Out of 258 studies, 16 articles were included for the analysis. Our meta-analysis revealed that using vitamins in cryopreservation media could increase motility by 4.60% (95% CI 6.16, 3.05; P = 0.0001), viability by 5.71% (95% CI 9.71, 1.72; P = 0.0001), and DNA integrity by 10.20% (95% CI 12.98, 7.42; P = 0.0001) in cryopreserved-thawed spermatozoa. We found a significant correlation between using vitamins and improved spermatozoa quality; the sperm motility and viability were improved and DNA fragmentation was reduced after thawing by vitamins. However, we could not emphasize on any type or dose of vitamins but we conclude that the anti-oxidative function of vitamins is the main reason for these benefits.

The Roles of MicroRNAs in Male Infertility

MicroRNAs applications were vastly studied throughout the years, spanning from potential cancer biomarkers to targeted therapies for various diseases. Out of these utilizations, this paper focuses on their role in male infertility. Approximately 10–15% of worldwide couples are affected by infertility. Out of these, 50% are due to male determinants. The majority of cases still have an undetermined cause. Previous studies have found that the aberrant expression of microRNAs could be linked to certain reproductive dysfunctions in males. Further on, this study looked into the most recent literature published on this subject in order to assess the connection between the up-/down-regulation of various microRNAs and the roles they play in male infertility. MicroRNAs were found to be abundant and stable in the seminal liquid, which led to a facile identification using regular RNA detection methods. It was observed that the concentration of microRNAs in semen was modified in the case of patients suffering from asthenozoospermia and azoospermia. Moreover, idiopathic male infertility was associated with a single nucleotide polymorphism of the microRNA binding site. Future studies should focus their attention on discovering future treatments against male infertility targeting specific microRNAs and also on developing new and improved contraceptive methods.

A potential mechanism associated with lead-induced spermatogonia and Leydig cell toxicity and mitigative effect of selenium in chicken

Lead (Pb) is a toxic heavy metal pollutants and can damage male reproductive function. Selenium (Se) possesses an ability of antagonizing Pb toxicity. However, biological events in the process of Pb toxicity and mitigative effect of Se are not well understood. The aim of present research was to investigate potential mechanism of Se against Pb toxicity from the perspective of oxidative stress, heat shock response and autophagy in the spermatogonia and Leydig cell of chicken. The cells from one-day-old male Hyline chickens were treated with Se (0.5 μmol/L) and/or Pb (20 μmol/L) for 24 h, respectively. Cell viability, cell ultrastucture, Pb and Se concentrations, testosterone level, oxidative stress indicators and relative expression of heat shock proteins (HSPs) and autophagy-related genes were measured. The results showed that spermatogonia was more tolerant to Pb than Leydig cell; cell injury was confirmed via histological assessment, cell viability and testosterone level; oxidative stress was further indicated by the decrease of catalase, glutathione peroxidase, glutathione-s-transferase and superoxide dismutase activities and the increase of malondialdehyde and reactive oxygen species contents. Pb increased expression of HSPs (27, 40, 60, 70 and 90). Meanwhile Pb induced autophagy through up-regulation of autophagy-related proteins 5, Beclin 1, Dynein, light chain 3 (LC3)-I and LC3-II and down-regulation of mammalian target of rapamycin in two type cells of chicken. However, Se intervention mitigated the aforementioned alterations caused by Pb. In conclusion, Pb led to oxidative stress, which triggered heat shock response and autophagy; Se administration mitigated reproductive toxicity of Pb through strengthening antioxidant defense in the spermatogonia and Leydig cell of chicken.

Lack of trusted diagnostic tools for undetermined male infertility

Semen analysis is the cornerstone of evaluating male infertility, but it is imperfect and insufficient to diagnose male infertility. As a result, about 20% of infertile males have undetermined infertility, a term encompassing male infertility with an unknown underlying cause. Undetermined male infertility includes two categories: (i) idiopathic male infertility-infertile males with abnormal semen analyses with an unknown cause for that abnormality and (ii) unexplained male infertility-males with "normal" semen analyses who are unable to impregnate due to unknown causes. The treatment of males with undetermined infertility is limited due to a lack of understanding the frequency of general sperm defects (e.g., number, motility, shape, viability). Furthermore, there is a lack of trusted, quantitative, and predictive diagnostic tests that look inside the sperm to quantify defects such as DNA damage, RNA abnormalities, centriole dysfunction, or reactive oxygen species to discover the underlying cause. To better treat undetermined male infertility, further research is needed on the frequency of sperm defects and reliable diagnostic tools that assess intracellular sperm components must be developed. The purpose of this review is to uniquely create a paradigm of thought regarding categories of male infertility based on intracellular and extracellular features of semen and sperm, explore the prevalence of the various categories of male factor infertility, call attention to the lack of standardization and universal application of advanced sperm testing techniques beyond semen analysis, and clarify the limitations of standard semen analysis. We also call attention to the variability in definitions and consider the benefits towards undetermined male infertility if these gaps in research are filled.

Staphylococcal infections and infertility: mechanisms and management

Infertility is a subject of worldwide concern as it affects approximately 15% of couples. Among the prime contributors of infertility, urogenital bacterial infections have lately gained much clinical importance. Staphylococcal species are commensal bacteria and major human pathogens mediating an array of reproductive tract infections. Emerging evidences are 'bit by bit' revealing the mechanisms by which Staphylococci strategically disrupt normal reproductive functions. Staphylococcal species can directly or through hematogenous routes can invade the reproductive tissues. In the testicular cells, epididymis as well as in various compartments of female reproductive tracts, the pathogen recognition receptors, toll-like receptors (TLRs), can recognize the pathogen-associated molecular patterns on the Staphylococci and thereby activate inflammatory signalling pathways. These elicit pro-inflammatory mediators trigger other immune cells to infiltrate and release further inflammatory agents and reactive oxygen species (ROS). Adaptive immune responses may intensify the inflammation-induced reproductive tissue damage, particularly via activation of T-helper (Th) cells, Th1 and Th17 by the innate components or by staphylococcal exotoxins. Staphylococcal surface factors binding with sperm membrane proteins can directly impair sperm functions. Although Staphylococci, being one of the most virulent bacterial species, are major contributors in infection-induced infertility in both males and females, the mechanisms of their operations remain under-discussed. The present review aims to provide a comprehensive perception of the possible mechanisms of staphylococcal infection-induced male and female infertility and aid potential interventions to address the lack of competent therapeutic measures for staphylococcal infection-induced infertility.

Sodium caseinate improves longevity and fertility of frozen bull semen

This study aimed to evaluate the effect of sodium caseinate added into freezing extender on the sperm parameters of cryopreserved bull semen and in vitro and in vivo fertility. One ejaculate of 30 bulls was used and processed using Botu-Bov (Botupharma, Botucatu, Brazil) with the addition of 20% egg yolk (EY) or 15% egg yolk with 2% sodium caseinate (EY + SC), subsequently submitted to freezing. Semen from both groups were evaluated immediately after thawing (T0) and after thermic stress at 37 °C for 90 min (T90), for sperm kinetics, by CASA method, and plasma membrane integrity (PMI), superoxide (O₂^-) concentration and high mitochondrial potential (HMP) by flow cytometry. In vitro fertilization (IVF) was performed to assess embryo cleavage rate on day 3, and blastocyst rate on day 8. The in vivo fertility test was performed using fixed-time artificial insemination (FTAI). In sperm evaluation, trajectory velocity, linear velocity, curvilinear velocity, and lateral head movement were higher (P < 0.05) in EY + SC at T0. At T90, while rectilinearity and linearity did not differ between EY and EY + SC (P > 0.05), the other parameters evaluated were higher in EY + SC. Similarly, the integrity of the plasma and acrosomal membranes (iPAM) was higher (P < 0.05) at T90 in EY + SC, but did not differ (P > 0.05) between the groups at T0. For O₂^- and HMP, the values were lower (P < 0.05) in EY + SC group in both moments; furthermore, EY + SC showed higher cleavage and blastocyst rates in IVF. Likewise, pregnancy rates by FTAI were higher (P < 0.05) in the EY + SC group. In conclusion, the addition of sodium caseinate into freezing extender improves sperm parameters of frozen-thawed bull semen and fertility rates on during in vitro and in vivo tests.

The addition of resveratrol in tris citric acid extender ameliorates post-thaw quality parameters, antioxidant enzymes levels, and fertilizing capability of buffalo (Bubalus bubalis) bull spermatozoa

Resveratrol is a natural grape-derived polyphenol with potent antioxidant properties that protect spermatozoa against lipid peroxidation (LPO) by eradicating free radicals. The objectives of this study were to 1) appraise the effects of resveratrol in extender on post-thaw quality parameters, antioxidant enzymes, adenosine triphosphate (ATP), DNA fragmentation, LPO and 2) fertilizing capability of buffalo bull spermatozoa. Semen was collected from four fertility proven bulls with artificial vagina thrice, evaluated initially, and diluted in five different extenders containing resveratrol (T4 = 100 μM, T3 = 50 μM, T2 = 20 μM, T1 = 10 μM), and control (no resveratrol), and evaluated after post-dilution and post-thawing stage of cryopreservation. Analysis of variance revealed that, there was no difference (P > 0.05) in any parameters due to treatments at post-dilution. However, at post-thawing, sperm progressive motility (%), plasma membrane integrity (%), mitochondrial membrane potential (%) and ATP levels (nmol/10⁶) were found higher in semen samples cryopreserved in T3 and 4 than control. Sperm supravital plasma membrane integrity (%) and viable/acrosome integrity were found higher in semen samples cryopreserved in T4 than control and T1. Furthermore, sperm catalase (U/mL), glutathione peroxidase (μM) and superoxide dismutase (U/mL) concentrations were found significantly higher in resveratrol treated groups as compared to the control. Conversely, DNA fragmentation (%) and LPO (μM/mL) were significantly (P > 0.05) decreased in semen samples cryopreserved in T4 in comparison to the control. Fertilizing capability was found higher in semen samples cryopreserved in T4 as compared to the control (%, 77.33 vs. 57.41, P < 0.05). It is concluded that the addition of resveratrol in extender ameliorates quality parameters, antioxidant enzymes levels and fertilizing capability, and alleviate DNA fragmentation and LPO in buffalo spermatozoa during cryopreservation.

Protective effects of Equisetum arvense methanolic extract on sperm characteristics and in vitro fertilization potential in experimental diabetic mice: An experimental study

Background

Diabetes mellitus is a metabolic disorder characterized by impaired insulin secretion or the inability of tissues to respond to insulin. This disease can damage the testis and reduce semen quality. Therefore, it can impair the potential for male fertility. Different herbal therapeutic treatments have been used to control diabetes and its complications.

Objective

This study aimed to evaluate the effects of streptozotocin-induced diabetes on sperm and in vitro fertilization (IVF) potential and investigate the protective effects of Equisetum arvense methanolic extract on diabetic mice.

Materials and Methods

Twenty-four adult male mice were divided into four groups: control-sham, diabetic, diabetic + Equisetum extract (250 mg/kg), and diabetic + Equisetum extract (500 mg/kg). After 45 days, sperm samples were collected from the cauda epididymis to evaluate the characteristics of sperm (including viability, count, motility, morphology and chromatin/DNA integrity of sperm) and the IVF potential.

Results

Sperm motility and viability were increased remarkably (p ≤ 0.001) in the treated groups compared with the non-treated diabetic group. The decrease in sperm count in the diabetic group compared with the treated groups was not significant. Moreover, the percentage of sperm with DNA damage, nuclear immaturity, and abnormal morphology was decreased significantly (p ≤ 0.001) in the treated groups compared with the diabetic group. The treated animals exhibited remarkably higher fertilization rates and a higher percentage of fertilized oocytes that developed toward the blastocyst stage compared with the non-treated diabetic group (p ≤ 0.001).

Conclusion

The methanolic extract of the Equisetum arvense inhibited diabetes-induced detrimental effects on sperm quality and fertilization rate, which may have been associated with hypoglycemic and antioxidative activities in this plant.

The efficacy of combined l-carnitine and l-acetyl carnitine in men with idiopathic oligoasthenoteratozoospermia: A systematic review and meta-analysis

The purpose of our analysis is to identify the effect of l-carnitine (LC) and l-acetyl carnitine (LAC) on the semen parameters of men with idiopathic oligoasthenoteratozoospermia (iOAT). We performed a comprehensive search to ascertain all the trials about LC and LAC in the treatment of iOAT and compared the results, including percentage of total sperm motility, sperm concentration, percentage of forward sperm motility, semen volume, percentage of atypical forms, total motile spermatozoa, forward motile spermatozoa and the number of pregnancies between the two groups that treated with LC + LAC or placebo respectively. Seven randomised controlled trials (RCTs) involving 693 patients were included in our analysis. We found that patients who treated with LC and LAC had significantly increased the percentage of forward sperm motility (MD 6.98; 95% CI 1.06-12.90; p = .02), total motile spermatozoa (MD 16.45; 95% CI 8.10-24.79; p = .0001), forward motile spermatozoa (MD 13.01; 95% CI 11.08-14.94; p < .00001) and the number of pregnancies (OR 3.76; 95% CI 1.66-8.50; p = .002). However, no significant differences were found in other semen indicators between the two groups. LC and LAC can significantly increase part of the semen parameters. The combination therapy of LC and LAC is effective in the men with iOAT.

Vitamin E but Not GSH Decreases Reactive Oxygen Species Accumulation and Enhances Sperm Production during In Vitro Maturation of Frozen-Thawed Prepubertal Mouse Testicular Tissue

Freezing-thawing procedures and in vitro culture conditions are considered as a source of stress associated with increased reactive oxygen species (ROS) generation, leading to a damaged cell aerobic metabolism and consequently to oxidative stress. In the present study, we sought to investigate whether vitamin E (Vit E) or reduced glutathione (GSH) enhances sperm production by decreasing ROS accumulation during in vitro maturation of prepubertal mice testes. Testes of prepubertal mice were cryopreserved using a freezing medium supplemented or not supplemented with Vit E and were cultured after thawing. In presence of Rol alone in culture medium, frozen-thawed (F-T) testicular tissues exhibited a higher ROS accumulation than fresh tissue during in vitro culture. However, Vit E supplementation in freezing, thawing, and culture media significantly decreased cytoplasmic ROS accumulation in F-T testicular tissue during in vitro maturation when compared with F-T testicular tissue cultured in the presence of Rol alone, whereas GSH supplementation in culture medium significantly increased ROS accumulation associated with cytolysis and tissue disintegration. Vit E but not GSH promoted a better in vitro sperm production and was a suitable ROS scavenger and effective molecule to improve the yield of in vitro spermatogenesis from F-T prepubertal mice testes. The prevention of oxidative stress in the cytoplasmic compartment should be regarded as a potential strategy for improving testicular tissue viability and functionality during the freeze-thaw procedure and in vitro maturation.

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.

In vitro response of human ovarian cancer cells to dietary bioflavonoid isoquercitrin

Isoquercitrin is a dietary bioflavonoid used as a food supplement. We studied the mechanism underlying its effect in human ovarian cancer cells using OVCAR-3 cell line. Viability, survival, apoptosis, release of human transforming growth factor-β1 (TGF-β1) and TGF-β1 receptor, and intracellular reactive oxygen species (ROS) generation by OVCAR-3 cells were examined after isoquercitrin treatment at concentrations 5, 10, 25, 50, and 100 μg mL^-1. AlamarBlue assay revealed that isoquercitrin did not cause any significant change (P > 0.05) in cell viability as compared to control. Apoptotic assay using flow cytometry did not find any significant change (P > 0.05) in the proportion of live, dead and apoptotic cells as compared to control. ELISA also showed that the release of human TGF-β1 and TGF-β1 receptor were not significantly (P > 0.05) affected by isoquercitrin as compared to control. Chemiluminescence assay demonstrated that lower concentrations (5, 10, and 25 μg mL^-1) were able to exhibit beneficial effects by inhibiting the generation of intracellular ROS. In contrast, elevated concentrations of 50 and 100 μg mL^-1 led to oxidative stress (P < 0.05). We concluded that the beneficial effect of isoquercitrin on ovarian cancer cells may be mediated by an antioxidative pathway that involves inhibition of intracellular ROS generation, thereby limiting oxidative stress.

Melatonin protects spermatogonia from the stress of chemotherapy and oxidation via eliminating reactive oxidative species

Busulfan is a widely used chemotherapeutic drug for chronic myelogenous leukemia and bone marrow transplantation. As a cell cycle nonspecific alkylation agent, busulfan has a severe side effect on germ cells, especially on spermatogonia before meiosis. Studies have revealed that busulfan causes DNA strand crosslinks in spermatogonia and induces apoptosis, and many corresponding strategies have been developed to ameliorate the side effects. However, fertility maintenance after busulfan treatment is still a challenging project in the clinic. Here, we demonstrated that continuous injection of melatonin effectively alleviated germline cytotoxicity both in recipient mice and cultured spermatogonia, and busulfan/melatonin recipient mice produced normal litters. We further revealed that melatonin rescues spermatogonia from apoptosis by neutralizing reactive oxidative species (ROS) induced by busulfan and recovered the phosphorylation of ATM and p53 to normal levels, and as a result apoptosis in spermatogonial progenitor cells was avoided. This study reports that pineal gland hormone melatonin effectively protects spermatogonia from the stress of chemotherapy and oxidation and reveals the underlying molecular mechanisms, which will provide an important hint for fertility protection in clinic.

Di(2-ethylhexyl)phthalate induces reproductive toxicity via JAZF1/TR4 pathway and oxidative stress in pubertal male rats

Di(2-ethylhexyl)phthalate (DEHP) is a typical endocrine-disrupting chemical and reproductive toxicant. Although previous studies have attempted to describe the mechanism by which DEHP exposure results in reproductive dysfunction, few studies focused on puberty, a critical period of reproductive development, and the increased susceptibility to injury in adolescents. To elucidate the mechanism underpinning the testicular effects of DEHP in puberty, we sought to investigate the JAZF1/TR4 pathway in the testes of pubertal rats. Specifically, we focused on the role of the JAZF1/TR4 pathway in male reproduction, including the genes JAZF1, TR4, Sperm 1, and Cyclin A1. In the present study, rats were exposed to increasing concentrations of DEHP (0, 250, 500, and 1000 mg/kg/day) by oral gavages for 30 days. Then we assayed testicular zinc and oxidative stress levels. Our results indicated that DEHP exposure could lead to oxidative stress and decrease the contents of testicular zinc. Additionally, significant morphological changes and cell apoptosis were observed in testes exposed to DEHP, as identified by hematoxylin and eosin staining and the terminal deoxynucleotidyl transferase-mediated nick and labeling assay. By measuring the expression levels of the above relevant genes by qPCR, we found the DEHP-induced increased expression of JAZF1 and decreased expression of TR4, Sperm 1, and Cyclin A1. Therefore, we have demonstrated that in vivo exposure to DEHP might induce reproductive toxicity in pubertal male rats through the JAZF1/TR4 pathway and oxidative stress.

Reactive Oxygen Species: the Dual Role in Physiological and Pathological Conditions of the Human Body

Reactive oxygen species (ROS) are well-known for playing a dual role as destructive and constructive species. Indeed, ROS are engaged in many redox-governing activities of the cells for the preservation of cellular homeostasis. However, its overproduction has been reported to result in oxidative stress, which is considered as a deleterious process, and is involved in the damage of cell structures that causes various diseased states. This review provides a concise view on some of the current research published in this topic for an improved understanding of the key roles of ROS in diverse conditions of health and disease. Previous research demonstrated that ROS perform as potential signaling molecules to control several normal physiological functions at the cellular level. Additionally, there is a growing body of evidence supporting the role of ROS in various pathological states. The binary nature of ROS with their profitable and injurious characteristics indicates the complexities of their specific roles at a biological compartment and the difficulties in establishing convenient intervention procedures to treat ROS-related diseases.

Effects of mobile phone exposure on metabolomics in the male and female reproductive systems

With current advances in technology, a number of epidemiological and experimental studies have reported a broad range of adverse effects of electromagnetic fields (EMF) on human health. Multiple cellular mechanisms have been proposed as direct causes or contributors to these biological effects. EMF-induced alterations in cellular levels can activate voltage-gated calcium channels and lead to the formation of free radicals, protein misfolding and DNA damage. Because rapidly dividing germ cells go through meiosis and mitosis, they are more sensitive to EMF in contrast to other slower-growing cell types. In this review, possible mechanistic pathways of the effects of EMF exposure on fertilization, oogenesis and spermatogenesis are discussed. In addition, the present review also evaluates metabolomic effects of GSM-modulated EMFs on the male and female reproductive systems in recent human and animal studies. In this context, experimental and epidemiological studies which examine the impact of mobile phone radiation on the processes of oogenesis and spermatogenesis are examined in line with current approaches.

Can Melissa officinalis improve chromatin structure and sperm parameters in a rat model of varicocele?

Excessive production of reactive oxygen species is a central mechanism in the pathology of varicocele; Melissa officinalis (MO) is a medicinal plant from the Lamiaceae family that has antioxidant activity. In this study, we have investigated the potential therapeutic effect of MO on sperm parameters and chromatin structure in varicocelised rat. Male Wistar rats were randomly assigned to control, sham, varicocele, MO treatment and placebo groups. Rats in varicocele, MO treatment and placebo groups underwent left varicocele induction. Following the operation, rats in placebo and MO treatment groups received normal saline or MO extract, daily for 10 weeks respectively. At 10 weeks after varicocele induction, sperm chromatin and parameters were evaluated in all groups. Chromatin structure was evaluated by aniline blue, acridine orange and toluidine blue staining. All three staining outcomes were increased in varicocele and placebo compared control (and sham) groups (p < 0.05). Sperm count, motility, morphology and vitality were decreased between varicocele and control (and sham) group (p < 0.05). Sperm parameters and chromatin staining (else AB staining) outcomes improve in MO treatment compared to varicocele and placebo groups (p < 0.05). These findings suggest that MO ameliorate the harmful effect of varicocele on sperm parameters and chromatin structure.

Gelatinases and their tissue inhibitors are associated with oxidative stress: a potential set of markers connected with male infertility

The expression and activity of matrix metalloproteinases (MMPs) may be regulated by oxidative stress in various pathophysiological processes; therefore, the aim of the present study was to analyse the associations between the expression of the gelatinases MMP-9 and MMP-2 and their tissue inhibitors TIMP-1, TIMP-2 and levels of total antioxidant capacity (TAC) and advanced oxidation protein products (AOPP) in seminal plasma prepared for artificial insemination. Levels of MMPs and TIMPs were evaluated using ELISA, whereas TAC and AOPP in the seminal plasma of 131 childless men and 38 fertile volunteers were determined spectrophotometrically. Seminal MMP-9 expression was higher in childless men than in fertile subjects, whereas there was no significant differences in MMP-2 expression between the analysed seminal groups. TIMP-1 and TIMP-2 expression was similar in all groups. However, TAC expression was significantly higher in infertile normozoospermic and oligozoospermic men and AOPP expression was higher in astheno-, oligo- and normozoospermic infertile patients than in fertile men. High AOPP, together with an increased MMP-9:TIMP-1 ratio alters the oxidative-antioxidative balance of the ejaculate, thereby reducing male fertility, and therefore these parameters may serve as additional diagnostic markers of semen quality and male reproductive potential.

Laboratory tests for oxidative stress

INTRODUCTION

Oxidative stress (OS) is considered a significant contributor to male infertility. A number of laboratory techniques have been developed to evaluate oxidative stress in the semen. We review these tests and their current use.

METHODS

A literature review was performed utilizing the PubMed search engine for articles studying OS etiology and impact on male fertility, and the laboratory tests used in its assessment.

RESULTS

The state of OS results from exaggerated production of oxygen-derived free radicals, also known as reactive oxygen species, to an extent overwhelming the body's antioxidant defense mechanisms. Several laboratory tests have been utilized in OS measurement during male fertility evaluation. These tests are classified into direct assays which measure the degree of oxidation within a sperm cell and indirect assays which estimate the detrimental effects of OS. The chemiluminescence assay, flow cytometry, nitroblue tetrazolium assay, and cytochrome c reduction are examples of direct assays while the myeloperoxidase test and measurements of lipid peroxidation, oxidation-reduction potential, and total antioxidant capacity are examples of the indirect assays.

CONCLUSION

OS measurement is an important tool that may help in understanding the pathophysiology of male infertility and provide valuable information that would guide treatment decisions and patient follow-up.

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

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

Thymoquinone Defeats Diabetes-Induced Testicular Damage in Rats Targeting Antioxidant, Inflammatory and Aromatase Expression

Antioxidants have valuable effects on the process of spermatogenesis, particularly with diabetes mellitus (DM). Therefore, the present study investigated the impact and the intracellular mechanisms by which thymoquinone (TQ) works against diabetes-induced testicular deteriorations in rats. Wistar male rats (n = 60) were randomly allocated into four groups; Control, Diabetic (streptozotocin (STZ)-treated rats where diabetes was induced by intraperitoneal injection of STZ, 65 mg/kg), Diabetic + TQ (diabetic rats treated with TQ (50 mg/kg) orally once daily), and TQ (non-diabetic rats treated with TQ) for 12 weeks. Results revealed that TQ significantly improved the sperm parameters with a reduction in nitric oxide (NO) and malondialdehyde (MDA) levels in testicular tissue. Also, it increased testicular reduced glutathione (GSH) levels and superoxide dismutase (SOD) activity. Interestingly, TQ induced downregulation of testicular inducible nitric oxide synthase (iNOS) and nuclear factor kappa-B (NF-κB) and significantly upregulated the aromatase protein expression levels in testicles in comparison with the diabetic rats. In conclusion, TQ treatment exerted a protective effect against reproductive dysfunction induced by diabetes not only through its powerful antioxidant and hypoglycemic effects but also through its downregulation of testicular iNOS and NF-κB along with upregulation of aromatase expression levels in diabetic rats.

Decreased melatonin levels and increased levels of advanced oxidation protein products in the seminal plasma are related to male infertility

Melatonin, an indolamine secreted by the pineal gland, is known as a powerful free-radical scavenger and wide-spectrum antioxidant. Therefore, the aim of this study was to correlate markers of oxidative protein damage (advanced oxidation protein products, AOPPs) and the total antioxidant capacity (TAC) with melatonin levels in the seminal plasma of men with azoospermia (n=37), theratozoospermia (n=29) and fertile controls (normozoospermia, n=37). Melatonin concentration was measured by radioimmunoassay. The levels of AOPP as well as TAC efficiency (determined by the ferric reducing antioxidant power, FRAP) were estimated by spectrophotometric methods. The concentration of melatonin and AOPP significantly differed in azoospermic (P<0.0001) and theratozoospermic (P<0.0001) patients versus fertile men, and correlated negatively (r=-0.33, P=0.0016). The TAC levels were significantly higher in azoospermia than in theratozoospermia (P=0.0022) and the control group (P=0.00016). In azoospermia, the AOPP concentration was also significantly higher than that observed in theratozoospermia (P=0.00029). Decreased levels of melatonin together with elevated AOPP altered the oxidative-antioxidative balance in the ejaculate, thereby reducing fertility. Therefore, melatonin and AOPP levels may serve as additional diagnostic markers of semen quality and male reproductive potential.

Egg white-derived peptides prevent male reproductive dysfunction induced by mercury in rats

Oxidative stress in known to contribute to the male reproductive dysfunction induced by mercury (Hg). Our study tested the hypothesis that the egg white hydrolysate (EWH), a potent antioxidant in vitro, is able to prevent the effects of prolonged Hg exposure on male reproductive system in rats. For this, rats were treated for 60 days with: a) Untreated - saline solution (i.m.); b) Hydrolysate - EWH (1 g/kg/day, gavage); c) Mercury - HgCl₂ (1st dose 4.6 μg/kg, subsequent doses 0.07 μg/kg/day, i.m.); d) Hydrolysate-Mercury. At the end of the treatment, sperm motility, count and morphological studies were performed; Reactive Oxygen Species (ROS) levels, lipid peroxidation, antioxidant capacity, histological and immunohistochemical assays on testis and epididymis were also carried out. As results, HgCl₂-treatment decreased sperm number, increased sperm transit time in epididymis and impaired sperm morphology. However, these harmful effects were prevented by EWH. HgCl₂-treatment also increased ROS levels, lipid peroxidation and antioxidant capacity in testis and epididymis as well as promoted testicular inflammation and histological changes in epididymis. EWH improved histological and immunohistochemical alterations, probably due to its antioxidant property. In conclusion, the EWH could represent a powerful natural alternative to protect the male reproductive system against Hg-induced sperm toxicity.

Measuring Sperm DNA Fragmentation and Clinical Outcomes of Medically Assisted Reproduction: A Systematic Review and Meta-Analysis

Sperm DNA fragmentation has been associated with reduced fertilization rates, embryo quality, pregnancy rates and increased miscarriage rates. Various methods exist to test sperm DNA fragmentation such as the sperm chromatin structure assay (SCSA), the sperm chromatin dispersion (SCD) test, the terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick end labelling (TUNEL) assay and the single cell gel electrophoresis (Comet) assay. We performed a systematic review and meta-analysis to assess the value of measuring sperm DNA fragmentation in predicting chance of ongoing pregnancy with IVF or ICSI. Out of 658 unique studies, 30 had extractable data and were thus included in the meta-analysis. Overall, the sperm DNA fragmentation tests had a reasonable to good sensitivity. A wide variety of other factors may also affect the IVF/ICSI outcome, reflected by limited to very low specificity. The constructed hierarchical summary receiver operating characteristic (HSROC) curve indicated a fair discriminatory capacity of the TUNEL assay (area under the curve (AUC) of 0.71; 95% CI 0.66 to 0.74) and Comet assay (AUC of 0.73; 95% CI 0.19 to 0.97). The SCSA and the SCD test had poor predictive capacity. Importantly, for the TUNEL assay, SCD test and Comet assay, meta-regression showed no differences in predictive value between IVF and ICSI. For the SCSA meta-regression indicated the predictive values for IVF and ICSI were different. The present review suggests that current sperm DNA fragmentation tests have limited capacity to predict the chance of pregnancy in the context of MAR. Furthermore, sperm DNA fragmentation tests have little or no difference in predictive value between IVF and ICSI. At this moment, there is insufficient evidence to recommend the routine use of sperm DNA fragmentation tests in couples undergoing MAR both for the prediction of pregnancy and for the choice of treatment. Given the significant limitations of the evidence and the methodological weakness and design of the included studies, we do urge for further research on the predictive value of sperm DNA fragmentation for the chance of pregnancy after MAR, also in comparison with other predictors of pregnancy after MAR.

Oxidation-reduction potential of semen: what is its role in the treatment of male infertility?

The diagnosis of male infertility relies largely on conventional semen analysis, and its interpretation has a profound influence on subsequent management of patients. Despite poor correlation between conventional semen parameters and male fertility potential, inclusion of advanced semen quality tests to routine male infertility workup algorithms has not been widely accepted. Oxidative stress is one of the major mediators in various etiologies of male infertility; it has deleterious effects on spermatozoa, including DNA damage. Alleviation of oxidative stress constitutes a potential treatment strategy for male infertility. Measurement of seminal oxidative stress is of crucial role in the identification and monitoring of patients who may benefit from treatments. Various tests including reactive oxygen species (ROS) assay, total antioxidant capacity (TAC) assay or malondialdehyde (MDA) assay used by different laboratories have their own drawbacks. Oxidation-reduction potential (ORP) is a measure of overall balance between oxidants and antioxidants, providing a comprehensive measure of oxidative stress. The MiOXSYS™ System is a novel technology based on a galvanostatic measure of electrons; it presents static ORP (sORP) measures with static referring to the passive or current state of activity between oxidants and antioxidants. Preliminary studies have correlated sORP to poor semen qualities. It is potentially useful in prognostication of assisted reproductive techniques outcomes, screening of antioxidants either in vivo or during IVF cycles, identification of infertile men who may benefit from treatment of oxidative stress, and monitoring of treatment success. The simplified laboratory test requiring a small amount of semen would facilitate clinical application and research in the field. In this paper, we discuss the measurement of ORP by the MiOXSYS System as a real-time assessment of seminal oxidative stress, and argue that it is a potential valuable clinical test that should be incorporated into the male infertility workup and become an important guide to the treatment of oxidative stress-induced male infertility.

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.