Effect of dietary selenium deficiency on the in vitro fertilizing ability of mice spermatozoa

Serological and histolomorphological investigation of camel bulls testes (Camelus dromedaries) during the rutting and non-rutting seasons

BACKGROUND

Camels are bred for their milk, meat, wool and hair, transportation, and their excrement as fuel. The seasonal reproduction of camel bull is accompanied by changes in sexual activity, the morphology, and function of the testes. This study aimed to evaluate the seasonal fluctuations in serum testosterone (T) levels as well as total antioxidant capacity (TAC) and malondialdehyde (MDA) levels in the testes of dromedary bulls (Camelus dromedarius) during the rutting and non-rutting seasons. Moreover, the impact of rutting season on the testicular size and histomorphology was also observed. Seventy mature dromedary bulls were divided into a rutting group (n = 35) and a non-rutting group (n = 35). From these bulls, blood samples and testes were collected during the rutting season (October to April) and non-rutting season (May to September) from a local slaughterhouse.

RESULTS

All parameters changed significantly during rutting and non-rutting periods in camel bulls. The levels of TAC in testes, and serum T were significantly (P < 0.05) higher in the rutting group than in the non-rutting group. However, testicular MDA was significantly (P < 0.05) lower in the rutting group than in the non-rutting group. TAC was negatively correlated with MDA (r = -0.59, p < 0.01). Moreover, in the rutting group and the non-rutting group, T was positively correlated with levels of TAC (r = 0.66, p < 0.0003). Additionally, testicular size (length, breadth, and thickness) was significantly greater in camels during the rutting season than in camels during the non-rutting season. Moreover, the number and diameter of seminiferous tubules, and spermatogenesis increased during the rutting season, whereas, the collagen content and apoptosis increased during the non-rutting season.

CONCLUSION

This study revealed that the rutting normal breeding season (NBS, rutting group) was associated with higher levels of total antioxidant capacity (TAC), T, and spermatogenic activity while the collagen content, concentrations of MDA (the oxidative stress factor) and apoptosis (an outcome of oxidative stress) were lower than those in the low breeding season (LBS, non-rutting group). In addition, the testicular size and seminiferous tubule diameter and number were higher during the NBS.

Trace and essential elements as vital components to improve the performance of the male reproductive system: Implications in cell signaling pathways

Successful male fertilization requires the main processes such as normal spermatogenesis, sperm capacitation, hyperactivation, and acrosome reaction. The progress of these processes depends on some endogenous and exogenous factors. So, the optimal level of ions and essential and rare elements such as selenium, zinc, copper, iron, manganese, calcium, and so on in various types of cells of the reproductive system could affect conception and male fertility rates. The function of trace elements in the male reproductive system could be exerted through some cellular and molecular processes, such as the management of active oxygen species, involvement in the action of membrane channels, regulation of enzyme activity, regulation of gene expression and hormone levels, and modulation of signaling cascades. In this review, we aim to summarize the available evidence on the role of trace elements in improving male reproductive performance. Also, special attention is paid to the cellular aspects and the involved molecular signaling cascades.

Selenium Deficiency Leads to Reduced Skeletal Muscle Cell Differentiation by Oxidative Stress in Mice

Selenium (Se) is one of the essential trace elements in animal organisms with good antioxidant and immune-enhancing abilities. In this study, we investigated the effect and mechanism of Se deficiency on skeletal muscle cell differentiation. A selenium-deficient skeletal muscle model was established. The skeletal muscle tissue and blood Se content were significantly reduced in the Se deficiency group. HE staining showed that the skeletal muscle tissue had a reduced myofiber area and nuclei and an increased myofascicular membrane with Se deficiency. The TUNEL test showed massive apoptosis of skeletal muscle cells in Se deficiency. With Se deficiency, reactive oxygen species (ROS) and malondialdehyde (MDA) increased, and the activities of glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and catalase (CAT) were inhibited. In in vitro experiments, microscopic observations showed that the low-Se group had reduced C2C12 cell fusion and a reduced number of differentiated myotubes. In addition, qPCR results showed that differentiation genes (Myog, Myod, Myh2, Myh3, and Myf5) were significantly reduced in the low Se group. Meanwhile, Western blot analysis showed that the levels of differentiation proteins (Myog, Myod, and Myhc) were significantly reduced in the low-Se group. This finding indicates that Se deficiency reduces the expression of skeletal muscle cell differentiation factors. All the above data suggest that Se deficiency can lead to oxidative stress in skeletal muscle, resulting in a reduction in the differentiation capacity of muscle cells.

Physiological Benefits of Novel Selenium Delivery via Nanoparticles

Dietary selenium (Se) intake within the physiological range is critical to maintain various biological functions, including antioxidant defence, redox homeostasis, growth, reproduction, immunity, and thyroid hormone production. Chemical forms of dietary Se are diverse, including organic Se (selenomethionine, selenocysteine, and selenium-methyl-selenocysteine) and inorganic Se (selenate and selenite). Previous studies have largely investigated and compared the health impacts of dietary Se on agricultural stock and humans, where dietary Se has shown various benefits, including enhanced growth performance, immune functions, and nutritional quality of meats, with reduced oxidative stress and inflammation, and finally enhanced thyroid health and fertility in humans. The emergence of nanoparticles presents a novel and innovative technology. Notably, Se in the form of nanoparticles (SeNPs) has lower toxicity, higher bioavailability, lower excretion in animals, and is linked to more powerful and superior biological activities (at a comparable Se dose) than traditional chemical forms of dietary Se. As a result, the development of tailored SeNPs for their use in intensive agriculture and as candidate for therapeutic drugs for human pathologies is now being actively explored. This review highlights the biological impacts of SeNPs on growth and reproductive performances, their role in modulating heat and oxidative stress and inflammation and the varying modes of synthesis of SeNPs.

Low-Se Diet Can Affect Sperm Quality and Testicular Glutathione Peroxidase-4 activity in Rats

This study aimed to observe the influence of selenium (Se) deficiency on sperm quality and selenoprotein expression in rats. Four-week male Wista rats were randomly divided into three groups: Se-A, Se-L, and Se-D (respectively for Se- adequate, low, and deficient group). After 9 weeks, the rats were sacrificed by anesthesia, with the cauda epididymidis quickly fetched for sperm count, motility, and deformity. Meanwhile the blood, liver, brain, heart, and testis were collected for Se and biochemical analysis. It was found that the rats in Se-D had poor growth, while the Se concentrations in blood, liver, and heart for Se-D decreased significantly, compared with Se-A and Se-L (p < 0.01). But no significant difference was observed in testis and brain and also no statistical significance for sperm count. The sperm motility for Se-A (63.07%) was significantly higher than Se-L (53.91%) and Se-D (54.15%). Deformities were observed in both Se-L and Se-D. Both glutathione peroxidases (GPxs) and selenoprotein-P (SEPP1) levels in plasma and tissues of Se-D were significantly lower than those of Se-A and Se-L (p < 0.01). The SEPP1 levels in heart and brain of Se-L were lower than Se-A (p < 0.01). There was no statistical difference for GPx1 between Se-A and Se-L. The GPx4 level in testis of Se-L was lower than Se-A (p < 0.05). However, the SEPP1 in plasma, liver, testis, and the GPx3 level in plasma of Se-L were higher than those of Se-A (p < 0.05 or p < 0.01). Our results show that dietary Se deficiency could reduce GPx4 and SEPP1 expression in testis, which further influence sperm motility and may cause sperm deformity. Selenoprotein expression in some tissues of Se-L was higher than that of Se-A, but sperm quality and GPx4 expression in testis were not improved for Se-L. Low active pseudoselenoproteins might be synthesized in low-Se condition. The underlying mechanism needs to be further investigated.

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.

Selenium Deficiency-Induced Damage and Altered Expression of Mitochondrial Biogenesis Markers in the Kidneys of Mice

Previous studies have raised concerns that kidney disease is often closely related to low serum Se levels in patients and that hyposelenemia may increase the vulnerability of patients to complications. However, few studies examining renal injury caused by Se deficiency have been conducted. To determine the effects of a selenium-deficient diet on renal function, a mouse model was fed a selenium-deficient diet (0.02 mg Se/kg) for 20 weeks. Meanwhile, mice in the control group (selenium-adequate) were fed a standard diet (0.18 mg Se/kg). The cellular models were established by lentiviral Trnau1ap-shRNA vectors transfected into mouse podocyte (MPC5) and mouse renal tubular epithelial (TCMK1) cell lines. Significant increases in serum creatinine levels and urinary protein/creatinine ratios were accompanied by increased MDA content in the Se-deficient group compared to the control group. The morphological observations of tissues showed widespread inflammation and ultrastructural changes in the Se-deficient group, such as swollen mitochondria and extensive podocyte fusion and renal tubular microvilli shedding. In addition, the expression of COXIV and cytochrome c was significantly downregulated in the Se-deficient group. Importantly, the mRNA levels of silent mating type information regulation 2 homolog 1 (SIRT1) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and the protein levels of SIRT1 were increased in the Se-deficient group compared with the normal control group. Our data indicate that Se deficiency induces renal injury in mice. The elevated oxidative stress caused by Se deficiency may result in mitochondrial damage, which might affect renal function. Moreover, the SIRT1/PGC1α axis likely plays an important role in the compensatory mechanism of mitochondrial dysfunction.

The Relationship between Sperm Oxidative Stress Alterations and IVF/ICSI Outcomes: A Systematic Review from Nonhuman Mammals

Achieving high embryo quality following IVF and ICSI procedures is a key factor in increasing fertility outcomes in human infertile couples. While the male factor is known to underlie infertility in about 50% of cases, studies performed in human infertile couples have not been able to define the precise effect of sperm affectations upon embryo development. This lack of consistency is, in most cases, due to the heterogeneity of the results caused by the multiple male and female factors that mask the concrete effect of a given sperm parameter. These biases can be reduced with the use of animal gametes, being a good approach for basic researchers to design more homogeneous studies analyzing the specific consequences of a certain affectation. Herein, we conducted a systematic review (March 2020) that assessed the relationship between sperm oxidative stress alterations and IVF/ICSI outcomes in nonhumans mammals. The review was conducted according to PRISMA guidelines and using the MEDLINE-PubMed and EMBASE databases. Thirty articles were included: 11 performed IVF, 17 conducted ICSI, and two carried out both fertilization methods. Most articles were conducted in mouse (43%), cattle (30%) and pig models (10%). After IVF treatments, 80% of studies observed a negative effect of sperm oxidative stress on fertilization rates, and 100% of studies observed a negative effect on blastocyst rates. After ICSI treatments, a positive relationship of sperm oxidative stress with fertilization rates (75% of studies) and with blastocyst rates (83% of studies) was found. In conclusion, the present systematic review shows that sperm oxidative stress is associated with a significant reduction in fertilization rates and in vitro embryo development.

Comparative effects of nano-selenium and sodium selenite supplementations on fertility in aged broiler breeder males

It is well documented that aging has negative effects on fertility. With increasing age, the activity of antioxidant enzymes are reduced and because of roosters sperm composition, a high proportion of polyunsaturated fatty acids (PUFAs), the probability of sperm damage increases. The objective of the present study was to compare the effects of nano-selenium and sodium selenite on fertility in aged male broiler breeder chickens. Thirty-five male broiler breeders (Cobb 500)® at 50 weeks of age were randomly divided into five equal groups: The control group was fed on a commercial diet, group T1 was fed on a commercial diet supplemented with sodium selenite (0.30 mg kg-1 feed), group T2, T3 and T4 were fed on a commercial diet supplemented with nano-selenium (0.15, 0.30 and 0.60 mg kg-1 feed, respectively). Sperm characteristics (sperm count, motility, viability, and maturity) as well as testicular histomorphometric features [tubule differentiation (TDI), spermiation (SPI), Sertoli cell (SCI) and meiotic (MI) indices] were assessed. The results showed that sperm characteristics were gradually decreased with age in the control group, however, it increased in group T3. Also, TDI, SPI, SCI, and MI in group T3 were higher than those of other groups. Our findings revealed that dietary supplementations with nano-selenium boosted fertility in aged male broiler breeders and the best results were obtained when the roosters received 0.30 mg kg-1 nano-selenium. Supplementation of nano-selenium in aged broiler breeder males might be effective to maintain flock fertility and/or increase the flock fertility.

Role of Selenium and Selenoproteins in Male Reproductive Function: A Review of Past and Present Evidences

Selenium (Se) is an important trace mineral having many essential roles at the cellular and organismal levels in animal and human health. The biological effects of Se are mainly carried out by selenoproteins (encoded by 25 genes in humans and 24 in mice). As an essential component of selenoproteins, Se performs structural and enzymic roles; in the latter context it is well known for its catalytic and antioxidative functions. Studies involving different animal models have added great value to our understanding regarding the potential implications of Se and selenoproteins in mammalian fertility and reproduction. In this review, we highlight the implications of selenoproteins in male fertility and reproduction followed by the characteristic biological functions of Se and selenoproteins associated with overall male reproductive function. It is evident from observations of past studies (both animal and human) that Se is essentially required for spermatogenesis and male fertility, presumably because of its vital role in modulation of antioxidant defense mechanisms and other essential biological pathways and redox sensitive transcription factors. However, bearing in mind the evidences from mainstream literature, it is also advisable to perform more studies focusing on the elucidation of additional roles played by the peculiar and canonical selenoproteins i.e., glutathione peroxidase 4 (GPX4) and selenoprotein P (SELENOP) in the male reproductive functions. Nevertheless, search for the elucidation of additional putative mechanisms potentially modulated by other biologically relevant selenoproteins should also be included in the scope of future studies. However, as for the implication of Se in fertility and reproduction in men, though a few clinical trials explore the effects of Se supplementation on male fertility, due to inconsistencies in the recruitment of subjects and heterogeneity of designs, the comparison of such studies is still complicated and less clear. Therefore, further research focused on the roles of Se and selenoproteins is awaited for validating the evidences at hand and outlining any therapeutic schemes intended for improving male fertility. As such, new dimensions could be added to the subject of male fertility and Se supplementation.

A new Thiocyanoacetamide protects rat sperm cells from Doxorubicin-triggered cytotoxicity whereas Selenium shows low efficacy: In vitro approach

Doxorubicin (DOX) exhibits a wide-ranging spectrum of antitumor activities which maintain its clinical use despite its devastating impact on highly proliferating cells. The present work was designed to develop a new approach which aims to protect male germ cells from DOX cytotoxicity. Thus, an assessment of the protective potential of a new thioamide analog (thiocyanoacetamide; TA) compared to selenium (Se) was performed in rat sperms exposed to DOX in vitro. Oxygen consumption rate (OCR) was measured after exposure to three different doses (0.5, 1, 1.5 and 2 μM) of DOX, Se or TA, and the suitable concentrations were selected for further studies afterwards. Motility, OCR in a time-dependent manner, glucose extracellular concentration and lipid peroxidation (LPO) were measured. Fatty acid (FA) content was assessed by gas chromatography (GC-FID). Cell death, superoxide anion (O₂^-), mitochondrial membrane potential (MMP), and DNA damage were evaluated by flow cytometry. TA association with DOX increased OCR and glucose uptake, improved cell survival and decreased DNA damage. The co-administration of DOX with Se increased OCR, significantly prevented O₂^- overproduction, and decreased LPO. Collected data brought new insights regarding this transformed TA, which showed better efficiency than Se in reducing DOX cytotoxic stress in sperms.

Evaluation of pigeon egg yolk for post thaw quality, enzyme leakage and fertility of buffalo (Bubalus bubalis) bull spermatozoa

Egg yolk is used as a cryoprotectant in semen preservation. However, its composition varies according to the species which may influence its effectiveness during the freeze-thaw process. Therefore, study was conducted to identify the optimum level of pigeon egg yolk (PEY) in Tris citric acid (TCA) extender for freezability and in vivo fertility of buffalo semen. Semen was collected at weekly intervals for a period of three weeks (replicates) from 6 Nili Ravi buffalo bulls (2 ejaculates/bull/replicate) and diluted with TCA extender (50 × 10⁶ motile spermatozoa ml^-1) containing 5%, 10%, 15% and 20% PEY or 20% CEY (control) and cryopreserved. Post-thaw sperm quality and extracellular enzymes leakage was assessed after thawing. Sperm motility, plasma membrane integrity, livability and viability was significantly higher in extenders containing 10% and 15% PEY compared to 5% PEY, 20% PEY or 20% CEY (controls). A dose-dependent decrease was recorded in the chromatin damage for the PEY, being lowest for the 15% and 20% PEY which was significantly less compared to controls (20% CEY). The extracellular GOT and LDH leakage was significantly lower (P < 0.05) in extender containing 10% and 15% PEY compared to the controls. Semen collected from 2 bulls, cryopreserved in extenders containing 15% PEY or 20% chicken egg yolk was assessed for fertility after artificial inseminations. A total of 400 buffaloes were inseminated (100 inseminations/extender/bull). The overall fertility rate was significantly higher (P < 0.05) with semen cryopreserved in extender containing 15% PEY (56%) compared to 20% CEY (42%; controls). In conclusion, pigeon egg yolk at 15% offers advantages over 20% chicken egg yolk in terms of in vitro post-thaw semen quality and in vivo fertility of buffalo.

Selenium supplementation in the form of selenium nanoparticles and selenite sodium improves mature male mice reproductive performances

OBJECTIVES

The current study was conducted to examine the possible protective and retentive effects of one-week intra-peritoneal (IP) administration of selenium nanoparticles (Se-NPs), compared to its bulk counterpart, selenite sodium (Ss), after one complete cycle of spermatogenesis in mature male mice.

MATERIALS AND METHODS

Thirty adult male mice were divided into 3 groups. Control group was administrated phosphate-buffered saline (IP) and the other groups received Ss (0.50 mg kg-1) and Se-NPs (0.50 mg kg-1) for seven successive days. Then, the animals were monitored for 28 days and finally sacrificed and tissue and blood samples were taken. Histopathological features, sperm quality, in vitro fertilization (IVF) capability and selenium (Se) content in testicular tissue were analyzed. Antioxidant enzyme activities including catalase, glutathione peroxidase, and superoxide dismutase as well as total antioxidant capacity and malondialdehyde levels were assessed in blood and the tissue samples.

RESULTS

Remarkable differences were found in sperm characteristics, histopathological features and oxidative stress biomarkers between control and treatment groups. Moreover, IVF evaluation and tissue Se concentration examination weren't similar for Se-NPs and Ss.

CONCLUSION

Conclusively, Se-treated groups had more antioxidant capacity than the control group, but sperm quality and histopathological features revealed that Se-NPs might possess more antioxidative and retentive potential compared to Ss in one spermatogenesis cycle.

Influence of maternal age on the effects of seleno-l-methionine in the model organism Daphnia pulex under standard and heat stress conditions

Selenium deficiency and toxicity increase the risk of adverse developmental and reproductive outcomes; however, few multi-stressor studies have evaluated the influence of maternal age on organic selenium dose-response and additional stressors over the life course. While multi-stressor research in mammalian models is time-consuming and expensive, use of alternative models can efficiently produce screening data for prioritizing research in mammalian systems. As a well-known eco-toxicological model, Daphnia pulex, may offer advantages in screening for impacts of multi-stressor exposures. We evaluated the influence of maternal age on the effects of seleno-methionine (SeMet) for lifespan, reproduction, and heat-stress resistance in D. pulex. Our results show effects of SeMet-treatment and maternal age, where the highest SeMet-treatment had reduced lifespan and absence of reproduction, and where Daphnia from late life broods had increased resistance to heat-induced stress. Further analysis suggests an additional interactive effect between maternal age and SeMet treatment on time to first reproduction.

Effect of Dietary Selenium Deficiency on the Cell Apoptosis and the Level of Thyroid Hormones in Chicken

This study assessed the effect of dietary selenium (Se) deficiency on male reproductive function in chicken. A total of 180 Hy-line laying cocks (1 day old; Weiwei) were randomly divided into 2 groups (n = 90) of Se-deficient chickens and control chickens. The control group was fed a basic diet (containing 0.15 mg of Se/kg). The Se-deficient group was fed a Se-deficient corn-soy basal diet (containing 0.033 mg of Se/kg). Fifteen chickens were killed in each group on days 30, 60, and 90, respectively. Then, serum and testes were collected and used in the detection of experimental index. Results indicated that GSH-Px activity and Bcl-2 mRNA level in the testes and thyroidal triiodothyronine (T3) and free triiodothyronine (FT3) levels in serum by dietary Se deficiency were significantly decreased compared to the corresponding control groups. Se deficiency-treated group showed a significant increase in MDA concent, TUNEL-positive cells, and mRNA level of Bax, Caspase3, and p53 in the testes and thyroidal thyroxine (T4), free thyroxine (FT4), and thyroid-stimulating hormone (TSH) levels in serum. Histopathologically, Se deficiency caused impairments in the testes. These results suggested that dietary Se deficiency exerts significant harmful effects on male reproductive organ and that the intrinsic and extrinsic pathways and the upstream regulators such as p53, Bax, and Bcl-2 were all involved in Se deficiency-induced testicular apoptosis.

Genotoxic effects of two-generational selenium deficiency in mouse somatic and testicular cells

Many studies have investigated genotoxic effects of high Se diets but very few have addressed the genotoxicity of Se deprivation and its consequences in germ cells and none in somatic cells. To address these data gaps, C57BL/6 male mice were subjected to Se deprivation starting in the parental generation, i.e. before conception. Mice were given a diet of either low (0.01mg Se/kg diet) or normal (0.23mg Se/kg diet) Se content. Ogg1-deficient (Ogg1 (-/-) ) mice were used as a sensitive model towards oxidative stress due to their reduced capacity to repair oxidised purines. Ogg1 (-/-) mice also mimic the repair characteristics of human post-meiotic male germ cells which have a reduced ability to repair such lesions. The genotoxicity of Se deficiency was addressed by measuring DNA lesions with the alkaline single cell gel electrophoresis (+ Fpg to detect oxidised DNA lesions) in somatic cells (nucleated blood cells and lung cells) and male germ cells (testicular cells). Total Se concentration in liver and GPx activity in plasma and testicular cells were measured. Gene mutation was evaluated by an erythrocyte-based Pig-a assay. We found that Se deprivation of F1 from their conception and until early adulthood led to the induction of DNA lesions in testicular and lung cells expressed as significantly increased levels of DNA lesions, irrespective of the mouse genotype. In blood cells, Se levels did not appear to affect DNA lesions or mutant cell frequencies. The results suggest that the testis was the most sensitive tissue. Thus, genotoxicity induced by the low Se diet in the spermatozoal genome has potential implications for the offspring.

Source of selenium supplementation influences testis selenium content and gene expression profiles in Single Comb White Leghorn roosters

Spermatogenesis is a tightly regulated, selenium-dependent process. Nutritional deficiencies, including Se, have been associated with decreased fertility. During Se depletion, testes preferentially retain Se while other tissues are depleted. This study was aimed at evaluating the effect of Se source (inorganic or organic yeast derived) on testes weight, Se content, and gene expression. At 17 weeks of age, roosters were randomly assigned to one of three treatments: basal diet (control), basal diet + 0.3 mg organic Se/kg organic yeast-derived Se (YS; Sel-Plex®, Alltech Inc.), or basal diet + 0.3 mg inorganic Se /kg inorganic Se as sodium selenite (SS). At 40 weeks of age, seven roosters from each treatment were euthanized and testes removed. Testes weight did not differ between treatments, but Se content was greater (P ≤ 0.01) in YS than SS and control. Testicular differential gene expression profiling was accomplished using the Affymetrix Genechip® chicken genome array. Ingenuity® pathway analysis revealed that Se supplementation, regardless of source, results in the up-regulation of genes governing cell structure/morphology. The enrichment of such pathways was greater with YS than SS. These expression patterns suggest that aside from playing a role in antioxidant defense, Se, especially in the organic YS form, is useful for maintaining testicular cell structure.

Protective effect of vitamin E and selenium combination on deltamethrin-induced reproductive toxicity in male rats

The current study was performed to assess the adverse effect of deltamethrin (DLM) on reproductive organs and fertility in male rats and to evaluate the protective role of vitamin E (VE) and selenium (Se) combination in alleviating the detrimental effect of DLM on male fertility. The lethal dose 50 (LD(50)) of DLM for male rats was estimated at 6 mg/kg bwt. Thirty male albino rats (10-weeks-old) were divided into three groups (10 rats each): Control group was injected subcutaneously with 2 ml/kg bwt saline twice weekly and was daily administered 2 ml distilled water intra-gastrically; DLM-treated group received 0.6 mg/kg bwt (1/10 LD(50)) DLM intra-gastrically once daily; DLM+VE/Se-treated group was injected subcutaneously with 1.2 mg/kg bwt Viteselen(®)15 (VE/Se) twice weekly with concurrent daily administration of 0.6 mg/kg bwt (1/10 LD(50)) DLM intra-gastrically. The experiment was conducted for 60 consecutive days. DLM caused a significant reduction in reproductive organs weights, sperm count, sperm motility percent, alive sperm percent, serum testosterone level and testicular reduced glutathione concentration (GSH). DLM-treated group showed a significant increase in sperm abnormalities and testicular malondialdehyde (MDA) concentrations. Histopathologically, DLM caused impairments in testes, epididymes and accessory sex glands. Conversely, treatment with VE/Se combination improved the reduction in the reproductive organs weights, sperm characteristics, DLM-induced oxidative damage of testes and the histopathological alterations of reproductive organs. Results indicate that DLM exerts significant harmful effects on male reproductive system and that the concurrent administration of VE/Se partly reduced the detrimental effects of DLM on male fertility.

Effect of selenium and vitamin E on acrosome reaction in porcine spermatozoa

Purpose

Selenium (Se) and vitamin E (Vit-E), as an integral part of antioxidant systems, play an important role in the motility and acrosome reaction (AR) of mammalian spermatozoa. The purpose of this study was to investigate the effect of Se and Vit-E on motility, viability, AR and accumulation of ammonia in the culture medium during different incubation periods in porcine sperm.

Methods

Sperm samples were washed, swum-up and incubated at 37°C for 1 and 3 h in Sp-TALP medium supplemented with sodium selenite (SS), seleon l-methionine (SeMet) and Vit-E in the presence or absence of ammonia. Sperm motility was determined on the basis of movement quality examined by phase microscopy. Viability and AR of spermatozoa were assessed by Hoechst 33258 and chlortetracycline (CTC) staining technique, and accumulation of ammonia was measured by the indophenol method. The incorporation of ¹⁴C(U)-glucose was assessed with a liquid scintillation counter.

Results

In experiment 1, the sperm motility, viability, AR and incorporation of ¹⁴C(U)-glucose increased significantly (P < 0.05) in SS, SeMet and Vit-E (5, 5 μg/l and 1.0 mM, respectively) compared with the control. In experiment 2, treatment of the sperm with SeMet and SeMet + Vit-E in the presence of 300 μM ammonia also resulted in a significant increase (P < 0.05) in the rate of motility, viability, AR and incorporation of ¹⁴C(U)-glucose. In contrast, the accumulation of ammonia was reduced by SeMet and SeMet + Vit-E compared with the other treatments.

Conclusions

These findings indicate that SeMet and SeMet + Vit-E may play an important role in reducing the accumulation of ammonia and subsequently in increasing the rate of AR and the utilization of glucose in porcine spermatozoa.