Ameliorative effects of nano-selenium against NiSO4-induced apoptosis in rat testes

Low Dose of Nickel and Benzo [a] Anthracene in Rat-Diet, Induce Apoptosis, Fibrosis, and Initiate Carcinogenesis in Liver via NF-Ƙβ Pathway

Environmental contaminants such as polycyclic aromatic hydrocarbon (PAH) and heavy metals are major contaminants of food such as fish thus serving as source of exposure to human. This study was designed to evaluate the carcinogenic risk and other risks associated with long-term consumption of environmentally relevant dose of nickel and benzo [a] anthracene in rats. Thirty-six (36) male rats weighing between 80 and 100 g were assigned into 6 groups of 6 animals each; normal, nickel-, and benzo [a] anthracene-exposed groups for 12 and 24 weeks, respectively. Micronucleus and comet analyses were done in the blood, liver, and bone marrow. Liver function, redox, and inflammatory markers (AST, ALT, GGT, SOD, GSH, MDA, protein carbonyl, protein thiol, total protein, IL-10, 1L-1β, TNF-α, TGF-β NF-Ƙβ, and 8-oxodeoxyguansine) were analysed by standard methods. Immuno-histochemical quantification of Bax, Bcl2, and Erk 1/2 as well as mRNA expression of cyclin D1 was done in liver. From the results, weight gain was observed in varying degrees throughout the exposure period. The polychromatic erythrocytes/normochromatic erythrocytes ratio > 0.2 indicates no cytotoxic effects on the bone marrow. Percentage-MnPCE in blood significantly (p < 0.05) increased throughout exposure duration. Percentage tail DNA in blood was significantly (< 0.05) increased at weeks 20 and 24 in the exposed groups and in liver at weeks 12 (16.22 ± 0.47) and 24 (17.00 ± 0.36) of nickel-exposed rats. The aspartate amino transferase (AST):alanine amino transferase (ALT) ratio indicated fatty liver disease in the benzo [a] anthracene (0.90) and acute liver injury in the nickel (> 10 times greater than the upper limits of the reference group) exposed groups during the first 12 weeks. Observation from the histological and cytological data of the liver revealed the presence of inflammation, fibrosis, and high nuclear/cytoplasmic ratio, respectively, in the nickel and benzo [a] anthracene groups. Only benzo [a] anthracene induced liver oxidative stress with significant (p < 0.05) decrease in SOD (0.64 ± 0.02) activity and increase in protein carbonyl (7.60 ± 0.80 × 10-5) and MDA (57.10 ± 6.64) concentration after 24 weeks. Benzo [a] anthracene up-regulated the cyclin D1 expression and significantly (p < 0.05) increased the levels of the cytokines. Nickel and benzo [a] anthracene significantly (p < 0.05) increased the Bax (183.45 ± 6.50 and 199.76 ± 10.04) and Erk 1/2 (108.25 ± 6.41 and 136.74 ± 4.22) levels when compared with the control (37.43 ± 22.22 and 60.37 ± 17.86), respectively. Overall result showed that the toxic effects of nickel and benzo [a] anthracene might involve fibrosis, cirrhosis, apoptosis, and inflammation of the liver. As clearly demonstrated in this study, benzo [a] anthracene after the 24 weeks of exposure stimulates carcinogenic process by suppressing the liver antioxidant capacity, altering apoptotic, cell proliferation, and differentiation pathways.

Selenium-Enriched Aspergillus oryzae A02 Enhances Testicular Antioxidant Capacity in Mice by Regulating Intestinal Microbiota and Serum Metabolite

Selenium (Se) is a trace element that is essential for health. Organic Se created by Se-enriched microorganisms has the characteristics of low toxicity, high bioavailability, and regulation of physiological functions. Here, the regulatory effect of Se-enriched Aspergillus oryzae A02 on the reproductive function of male mice and its potential molecular mechanism was studied. Specifically, twenty-four male mice were randomly divided into a control group and a Se-enriched A. oryzae A02 (Nano-Se) (daily gavage of 0.5 mg/kg, dissolved in saline) for an 8-week experiment. The results showed that Nano-Se intervention did not affect body weight and testicular index, but increased sperm concentration and seminiferous epithelium height in experimental mice, indicating that Nano-Se has the potential to improve the reproductive performance of male mice. Mechanistically, Nano-Se intervention increased the levels of antioxidant-related indicators catalase (CAT) and glutathione peroxidase (GSH-Px) in mouse serum, and increased the relative mRNA expression of GSH-Px, heme oxygenase-1 (HO-1), and NADPH quinine oxidoreductase-1 (NQO-1) in testicular tissues. We identified 9,10,13-trihydroxyoctadecenoic acids (TriHOMEs), stearidonic acid and selenomethionine linked with alpha-linolenic acid metabolism, selenocompound metabolism, folate biosynthesis, ubiquinone, and other terpenoid-quinone biosynthesis and biosynthesis of cofactors. In addition, Nano-Se did not influence the fecal bacterial alpha and beta diversity (P > 0.05), but increased the abundance of the Actinobacteriota and Proteobacteria phyla and the Staphylococcus and Corynebacterium genera, and lowered the abundance of the Bacteroidota phylum and the Lactobacillus and norank_f_Muribaculaceae genera. Nano-Se is considered a novel and promising nutritional regulator to improve reproductive function.

Oxidative Stress-Associated Male Infertility: Current Diagnostic and Therapeutic Approaches

Infertility is a prevalent global issue affecting approximately 17.5% of adults, with sole male factor contributing to 20-30% of cases. Oxidative stress (OS) is a critical factor in male infertility, disrupting the balance between reactive oxygen species (ROS) and antioxidants. This imbalance detrimentally affects sperm function and viability, ultimately impairing fertility. OS also triggers molecular changes in sperm, including DNA damage, lipid peroxidation, and alterations in protein expression, further compromising sperm functionality and potential fertilization. Diagnostic tools discussed in this review offer insights into OS markers, antioxidant levels, and intracellular ROS concentrations. By accurately assessing these parameters, clinicians can diagnose male infertility more effectively and thus tailor treatment plans to individual patients. Additionally, this review explores various treatment options for males with OS-associated infertility, such as empirical drugs, antioxidants, nanoantioxidants, and lifestyle modifications. By addressing the root causes of male infertility and implementing targeted interventions, clinicians can optimize treatment outcomes and enhance the chances of conception for couples struggling with infertility.

Insights into the effects of chronic combined chromium-nickel exposure on colon damage in mice through transcriptomic analysis and in vitro gastrointestinal digestion assay

Heavy metals interact with each other in a coexisting manner to produce complex combined toxicity to organisms. At present, the toxic effects of chronic co-exposure to heavy metals hexavalent chromium [Cr(VI)] and divalent nickel [Ni(II)] on organisms are seldom studied and the related mechanisms are poorly understood. In this study, we explored the mechanism of the colon injury in mice caused by chronic exposure to Cr or/and Ni. The results showed that, compared with the control group, Cr or/and Ni chronic exposure affected the body weight of mice, and led to infiltration of inflammatory cells in the colon, decreased the number of goblet cells, fusion of intracellular mucus particles and damaged cell structure of intestinal epithelial. In the Cr or/and Ni exposure group, the activity of nitric oxide synthase (iNOS) increased, the expression levels of MUC2 were significantly down-regulated, and those of ZO-1 and Occludin were significantly up-regulated. Interestingly, factorial analysis revealed an interaction between Cr and Ni, which was manifested as antagonistic effects on iNOS activity, ZO-1 and MUC2 mRNA expression levels. Transcriptome sequencing further revealed that the expression of genes-related to inflammation, intestinal mucus and tight junctions changed obviously. Moreover, the relative contents of Cr(VI) and Ni(II) in the Cr, Ni and Cr+Ni groups all changed with in-vitro gastrointestinal （IVG）digestion, especially in the Cr+Ni group. Our results indicated that the chronic exposure to Cr or/and Ni can lead to damage to the mice colon, and the relative content changes of Cr(VI) and Ni(II) might be the main reason for the antagonistic effect of Cr+Ni exposure on the colon damage.

Reactive oxygen species-scavenging nanomaterials for the prevention and treatment of age-related diseases

With increasing proportion of the elderly in the population, age-related diseases (ARD) lead to a considerable healthcare burden to society. Prevention and treatment of ARD can decrease the negative impact of aging and the burden of disease. The aging rate is closely associated with the production of high levels of reactive oxygen species (ROS). ROS-mediated oxidative stress in aging triggers aging-related changes through lipid peroxidation, protein oxidation, and DNA oxidation. Antioxidants can control autoxidation by scavenging free radicals or inhibiting their formation, thereby reducing oxidative stress. Benefiting from significant advances in nanotechnology, a large number of nanomaterials with ROS-scavenging capabilities have been developed. ROS-scavenging nanomaterials can be divided into two categories: nanomaterials as carriers for delivering ROS-scavenging drugs, and nanomaterials themselves with ROS-scavenging activity. This study summarizes the current advances in ROS-scavenging nanomaterials for prevention and treatment of ARD, highlights the potential mechanisms of the nanomaterials used and discusses the challenges and prospects for their applications.

Methylseleninic acid induces apoptosis of human bladder cancer cells through the ROS-mediated mitochondrial pathway

As the most common selenium derivative, methylseleninic acid (MSA) has attracted wide attention. Its apoptotic induction ability and the possible molecular mechanism in human bladder cancer (BC) J82 and T24 cells were investigated in the present study. We found that the survival of J82 and T24 cells were inhibited in a dose-dependent manner after MSA treatment. Propidium iodide (PI) staining and Annexin V-fluorescein isothiocyanate/PI double staining clarified that MSA stocked cells at G2 /M phase and caused apoptosis in J82 and T24 cells. Further, typical morphological features of apoptotic cells were also observed. Accumulation of reactive oxygen species (ROS) and loss of mitochondrial membrane potential were also detected by dichlorodihydrofluorescein diacetate and Rhodamin123 staining. Meanwhile, pretreatment with N-acetylcysteine, an ROS scavenging agent, found that the apoptosis of BC cells induced by MSA was related to the production of ROS. Western blot analysis results showed that MSA interrupted Bax/Bcl-2 balance, stimulated cytochrome c release into the cytoplasm, activated caspase-9 and caspase-3, and finally induced the apoptosis of the BC cells. These findings demonstrated that MSA was able to induce apoptosis in J82 and T24 cells through ROS-mediated mitochondrial apoptosis.

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.

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.

Nano-Selenium Alleviates Cadmium-Induced Acute Hepatic Toxicity by Decreasing Oxidative Stress and Activating the Nrf2 Pathway in Male Kunming Mice

Cadmium (Cd) is known as a highly toxic heavy metal and has been reported to induce hepatotoxicity in animals. Nano-selenium (NSe) is an antioxidant that plays many biological roles such as oxidative stress alleviation. The purpose of this study is to explore the mechanism of action by which NSe inhibits Cd-induced hepatic toxicity and oxidative stress. Sixty eight-week-old male Kunming mice were randomly divided into four groups (15 mice per group). The control group and cadmium groups received distilled water, whereas the sodium-selenite group received 0.2 mg/kg SSe and the NSe group received 0.2 mg/kg NSe intragastrically for 2 weeks. On the last day, all the other groups were treated with Cd (126 mg/kg) except for the control group. The results obtained in this study showed that NSe alleviated Cd-induced hepatic pathological changes. Furthermore, NSe reduced the activities of ALT and AST as well as the content of MDA, while elevated the activities of T-AOC, T-SOD and GSH (P < 0.05). In addition, the NSe group significantly increased mRNA expressions of Nrf2 pathway related molecules (Nrf2, HO-1, NQO-1, GST, GSH-Px, CAT and SOD) compared to the Cd group (P < 0.05). In conclusion, NSe shows its potentiality to reduce Cd-induced liver injury by inhibiting oxidative stress and activating the Nrf2 pathway.

Nano-selenium attenuates mitochondrial-associated apoptosis via the PI3K/AKT pathway in nickel-induced hepatotoxicity in vivo and in vitro

The aim of this study was to investigate the protective effects of Nano-Se against nickel (Ni)-induced hepatotoxicity and the potential mechanism. Hence, we constructed in vivo and in vitro models of Ni-induced hepatotoxicity. Sprague-Dawley (SD) rats were exposed to nickel sulfate (NiSO₄ , 5.0 mg/kg, i.p.) with or without Nano-Se (0.5, 1, and 2 mg/kg, oral gavage) co-administration for 14 days, and HepG2 cells were exposed to NiSO₄ (1500 μM) with or without Nano-Se (20 μM) for 24 h. Nano-Se obviously prevented Ni-induced hepatotoxicity indicated by ameliorating pathological change and decreasing Ni accumulation in rat livers. Ni induced a significant increase in hepatic activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GSH-Px), and malondialdehyde (MDA) level, decreased the glutathione (GSH) content while compared to those in the control group. Nano-Se administration improved the hepatic antioxidant capacity through increase hepatic GSH contents and GSH-Px activity, decrease the activities of SOD, CAT, and MDA level. Nano-Se improved the cell viability, decreased active oxygen (ROS) generation and ameliorated morphological changes of nuclear structures in Ni-treated HepG2 cells. In addition, Nano-Se inhibited the Ni-induced increases of cytochrome c, caspase-9, cleaved caspase-3, increased PI3K and AKT phosphorylation both in vivo and in vitro. Besides, the PI3K inhibitor Y294002 could inhibit the protective effects of Nano-Se on apoptosis. Thus, Nano-Se significantly activates PI3K/AKT signaling to ameliorate apoptosis in Ni-induced hepatotoxicity.

Anti-oxidant, anti-apoptotic, and mitochondrial regulatory effects of selenium nanoparticles against vancomycin induced nephrotoxicity in experimental rats

AIM

Nephrotoxicity is the major limiting factor for the clinical use of vancomycin (VCM) for treatment against multi-resistant Gram-positive bacteria. The present research aimed to investigate the ability of selenium nanoparticles (SeNPs) to protect against VCM-induced nephrotoxicity in rats.

MAIN METHODS

Experimental rats were divided into five groups; the first was the normal control, the second was treated with VCM (200 mg/kg twice/day, i.p.) for 7 days. The third, fourth, and fifth groups were treated orally with SeNPs (0.5, 1, and 2 mg/kg/day); respectively. SeNPs were administered for 12 days before VCM, 1 week simultaneously with VCM, and for another 1 week after its administration.

KEY FINDINGS

Levels of malondialdehyde (MDA), inducible nitric oxide synthase (iNOS), nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), and kidney injury molecule-1 (KIM-1) were significantly increased in kidney tissue after VCM administration. Expression of adenosine 5'-monophosphate-activated protein kinase (AMPK), Bcl-2 associated X protein (Bax), caspase 3 and caspase 9 in kidney tissue was significantly increased, while the antioxidant enzymes, mitochondrial complexes, the ATP levels and B-cell lymphoma protein 2 (Bcl-2) were decreased in kidney in the VCM-treated rats compared to the normal control group. Treatment with SeNPs significantly decreased levels of MDA, iNOS, NO, TNF-α, and KIM-1 in the kidney tissue. Administration of SeNPs also downregulated the expression of the proapoptotic agents and enhanced the activities of the antioxidant enzymes and the mitochondrial enzyme complexes in the kidney.

SIGNIFICANCE

SeNPs alleviated VCM-induced nephrotoxicity through their anti-oxidant, anti-inflammatory, anti-apoptotic and mitochondrial protective effects.

rno-miR-128-3p promotes apoptosis in rat granulosa cells (GCs) induced by norepinephrine through Wilms tumor 1 (WT1)

The mechanism related to ovarian follicular is complex, which has not been fully elucidated. Abundant reports have confirmed that the ovarian function development is closely related to sympathetic innervation. As one of the major neurotransmitters, norepinephrine (NE) is considered an effective regulator of ovarian functions like granulosa cell (GC) apoptosis. However, the mechanism between NE and GC apoptosis in rat is still unclear. In our study, GCs were isolated and cultured in vitro with NE treatment. The apoptosis of GCs was facilitated by NE. Wilms tumor 1 (WT1) was found to be significantly downregulated in GCs after NE treatment, and overexpression of WT1 repressed apoptosis in rat GCs induced by NE. rno-miR-128-3p was found to be significantly enhanced by NE in GCs, and inhibition of rno-miR-128-3p repressed apoptosis in rat GCs induced by NE. Mechanistically, rno-miR-128-3p interacted with WT1 and repressed its expression. In summary, inhibition of rno-miR-128-3p may enhance WT1 expression, and then repress NE-induced apoptosis in rat GCs. Our research may provide a new insight for the improvement of ovarian follicular development.

The Radioprotective Effects of Melatonin and Nanoselenium on DNA Double-Strand Breaks in Peripheral Lymphocytes Caused by I-131

Background:

One of the treatment modalities for thyroid cancer and hyperthyroidism is radioiodine-131 (I-131) therapy. The use of this therapeutic modality is not completely safe and can lead to oxidative stress, eventually DNA damages. However, these radiation-induced damages can be reduced by antioxidants. This study aimed to investigate the potential radioprotective effects of melatonin and selenium nanoparticles (SeNPs) on DNA double-stranded breaks (DSBs) caused by I-131.

Materials and Methods:

After obtaining informed consent, 6 ml blood was taken from each volunteer. The samples were divided into two general groups of control (without I-131) and with I-131. Each group was also divided into three subgroups, including without antioxidant, melatonin, and SeNPs. The samples of control group were incubated for 2 h after adding the antioxidants. The samples of I-131 group were first incubated for 1 h with the antioxidants and then the samples re-incubated for another 1 h after adding the I-131. Then, the samples were prepared for γH2AX assay.

Results:

The findings showed that after 1 h of incubation with 20 μCi I-131/2 mL, the DSB levels increased by 102.9% in comparison with the control group. In the I-131 group, there were significant reductions of the DSB levels after incubation with melatonin (P < 0.001) and SeNPs (P < 0.001) in comparison with the without antioxidant subgroup. Furthermore, the DSB levels at the melatonin + I-131 and the SeNPs + I-131 subgroups decreased to 38% and 30%, respectively, compared to the I-131 subgroup.

Conclusion:

According to the obtained findings, it can be concluded that the use of melatonin and SeNPs (as radioprotector agents) can reduce the DSB levels induced by I-131 in peripheral lymphocytes.

Antagonistic effect of nano-selenium on hepatocyte apoptosis induced by DEHP via PI3K/AKT pathway in chicken liver

Di-(2-ethylhexyl) phthalate (DEHP) is a common plasticizer which is mainly used as a kind of plastic additive to increase the flexibility of plastic products. Given the widespread use of plastic products, DEHP, as a ubiquitous artificial pollutant, are widely present in the environment. In addition, DEHP could cause biological damage in various organs through oxidative stress. Nano-Selenium, a novel form of selenium, has a wide variety of biomedical applications as an antioxidant, anticancer and anti-inflammatory agent. Nevertheless, researches on the toxicity of DEHP in chicken hepatocyte lines is insufficient. In particular, researches on the interaction between DEHP and nano-selenium is insufficient in chicken cell. Therefore, the innovation of this study is to explore the theoretical mechanism of DEHP toxicity in hepatocytes and the antagonistic effect of nano-selenium on a series of damage in chicken hepatocytes caused by DEHP. Our results showed that, after DEHP exposure, oxidative stress levels in hepatocytes increased, and the mRNA and protein levels of apoptosis-related genes p53, Capsase9, Caspase3 and Bax increased significantly except Bcl-2. The protein levels of apoptosis markers cleaved-Caspase9 and cleaved-Caspase3 also increased significantly. Moreover, the result of TUNEL assay also showed that the level of apoptotic cells increased after DEHP exposure. Meanwhile, the mRNA and protein levels of PI3K, AKT and p-AKT decreased. Therefore, DEHP is able to enhance the degree of oxidative damage and apoptosis of chicken liver cells. Nevertheless, the addition of nano-selenium can reverse the above changes. Experimental results revealed that nano-selenium antagonizes the toxic effects of DEHP via the PI3K/AKT pathway.

Immunotoxicity of nickel: Pathological and toxicological effects

Nickel (Ni) is a widely distributed metal in the environment and an important pollutant because of its many industrial applications. With increasing incidences of Ni contamination, Ni toxicity has become a global public health concern and recent evidence suggests that Ni adversely affects the immune system. Hence, this paper reviews the literature on immune-related effects of Ni exposure, the immunotoxicological effects of Ni, and the underlying mechanism of Ni immunotoxicity. The main focus was on the effect of Ni on the development of organs of immune system, lymphocyte subpopulations, cytokines, immunoglobulins, natural killer (NK) cells, and macrophages. Moreover, Ni toxicity also induces inflammation and several studies demonstrated that Ni could induce immunotoxicity. Excessive Ni exposure can inhibit the development of immune organs by excessively inducing apoptosis and inhibiting proliferation. Furthermore, Ni can decrease T and B lymphocytes, the specific mechanism of which requires further research. The effects of Ni on immunoglobulin A (IgA), IgG, and IgM remain unknown and while Ni inhibited IgA, IgG, and IgM levels in an animal experiment, the opposite result was found in research on humans. Ni inhibits the production of cytokines in non-inflammatory responses. Cytokine levels increased in Ni-induced inflammation responses, and Ni activates inflammation through toll like (TL)4-mediated nuclear factor-κB (NF-κB) and signal transduction cascades mitogen-activated protein kinase (MAPK) pathways. Ni has been indicated to inactivate NK cells and macrophages both in vitro and in vivo. Identifying the mechanisms underlying the Ni-induced immunotoxicity may help to explain the growing risk of infections and cancers in human populations that have been exposed to Ni for a long time. Such knowledge may also help to prevent and treat Ni-related carcinogenicity and toxicology.

Selenium and Nano-Selenium Biofortification for Human Health: Opportunities and Challenges

Selenium is an essential micronutrient required for the health of humans and lower plants, but its importance for higher plants is still being investigated. The biological functions of Se related to human health revolve around its presence in 25 known selenoproteins (e.g., selenocysteine or the 21st amino acid). Humans may receive their required Se through plant uptake of soil Se, foods enriched in Se, or Se dietary supplements. Selenium nanoparticles (Se-NPs) have been applied to biofortified foods and feeds. Due to low toxicity and high efficiency, Se-NPs are used in applications such as cancer therapy and nano-medicines. Selenium and nano-selenium may be able to support and enhance the productivity of cultivated plants and animals under stressful conditions because they are antimicrobial and anti-carcinogenic agents, with antioxidant capacity and immune-modulatory efficacy. Thus, nano-selenium could be inserted in the feeds of fish and livestock to improvise stress resilience and productivity. This review offers new insights in Se and Se-NPs biofortification for edible plants and farm animals under stressful environments. Further, extensive research on Se-NPs is required to identify possible adverse effects on humans and their cytotoxicity.

Selenium attenuates diclofenac-induced testicular and epididymal toxicity in rats

The adverse effect of diclofenac administration on the male reproductive organ in both humans and rats has been reported. Selenium, a trace element vital in nutrition, plays a significant part in cellular redox homeostasis, including male reproduction. However, the impact of selenium on male reproductive toxicity associated with diclofenac administration is lacking in the literature. The current investigation assessed the modulatory effects of selenium on diclofenac-mediated reproductive toxicity in rats. Rats were treated for fourteen consecutive days, either with diclofenac (10 mg/kg) or co-treated with selenium (0.125 and 0.25 mg/kg) body weight. Sperm parameters, enzymes of testicular function, luteinizing, follicle-stimulating hormone and testosterone were assessed in addition to oxidative stress indices and histopathological changes. Selenium significantly alleviated diclofenac-induced decreases in sperm count and motility, testicular function enzymes and levels of luteinizing hormone and testosterone in serum. Moreover, selenium co-administration at 0.125 and 0.25 mg/kg inhibited the diclofenac-induced decrease of antioxidant enzyme activities and increased oxidative stress parameters-lipid peroxidation, reactive nitrogen and oxygen species-in epididymis and testes of rats. Selenium (0.25 mg/kg) alone ameliorated diclofenac-mediated histological injuries in exposed rats. Collectively, selenium enhanced testicular and epididymal function in diclofenac-treated rats by suppressing nitrosative and oxidative stress in rats.

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.

Effects of selenium supplementation on lung oxidative stress after exposure to exhaust emissions from pyrolysis oil, biodiesel and diesel

The exposure to exhaust emissions from fuels as diesel and pyrolysis oil may result in adverse effects on human lungs. This study investigated the effects of exposing mice to the exhaust emissions from diesel, biodiesel or pyrolysis oil, for 1 hour/day for 3 days, on lung oxidative stress and whether selenium administration into these mice affects the oxidative stress. The levels of lung malondialdehyde and nitric oxide were increased after exposure to pyrolysis oil exhaust. The intraperitoneal injection of 1.78 μg selenium/kg body weight 15 minutes before the exposure to the pyrolysis oil exhaust (pyrolysis oil + selenium group) restored the normal levels of malondialdehyde and nitric oxide. The catalase and SOD activities were decreased in the groups of the mice exposed to the exhaust emissions from pyrolysis oil, biodiesel or diesel. Selenium pretreatment of these groups showed no significant change in the activities of both enzymes. In conclusion, the increased lung levels of malondialdehyde and nitric oxide after the exposure to the exhaust emission from pyrolysis oil were restored to normal by selenium administration.