Selenium

Effects of nanoselenium on the performance, blood indices, and milk metabolites of dairy cows during the peak lactation period

To compare the impact of nanoselenium and sodium selenite on the performance, blood indices, and milk metabolites of dairy cows during the peak lactation period, two groups of dairy cows under the same conditions were selected as the control group (CON group) and treatment group (NSe group) for a 38-day (10 days for adaptation and 28 days for sampling) experiment. The control group (CON) was provided a basal diet +3.3 g/d of sodium selenite (purity1%), whereas the nanoselenium group (NSe) was offered the same diet +10 mL/d of nanoselenium (selenium concentration 1,500 mg/L). The results showed that NSe significantly increased the milk yield, milk selenium content, and feed efficiency (p < 0.05), but had no significant effect on other milk components (p > 0.05). NSe significantly increased blood urea nitrogen (BUN) and alkaline phosphatase (ALP) (p < 0.05), but had no significant effects on malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), blood total antioxidant capacity (T-AOC), or blood selenium (p > 0.05). In addition, the nontargeted metabolomics of the milk was determined by LC-MS technology, and the differentially abundant metabolites and their enrichment pathways were screened. According to these findings, NSe considerably increased the contents of cetylmannoside, undecylenoic acid, 3-hydroxypentadecanoic acid, 16-hydroxypentadecanoic acid, threonic acid, etc., but decreased the contents of galactaric acid, mesaconic acid, CDP-glucose etc. Furthermore, the enriched metabolic pathways that were screened with an impact value greater than 0.1 included metabolism of niacin and niacinamide, pyruvate, citrate cycle, riboflavin, glycerophospholipid, butanoate and tyrosine. Pearson correlation analysis also revealed a relationship between different milk metabolites and blood selenium, as well as between milk selenium and blood biochemical indices. In conclusion, compared with sodium selenite, nanoselenium improves the milk yield, feed efficiency, and milk selenium content of dairy cows and regulates milk metabolites and related metabolic pathways in Holstein dairy cows during the peak lactation period, which has certain application prospects in dairy production.

Genome-wide analysis of NAC transcription factors and exploration of candidate genes regulating selenium metabolism in Broussonetia papyrifera

MAIN CONCLUSION

Genome-wide identification revealed 79 BpNAC genes belonging to 16 subfamilies, and their gene structures and evolutionary relationships were characterized. Expression analysis highlighted their importance in plant selenium stress responses. Paper mulberry (Broussonetia papyrifera), a deciduous arboreal plant of the Moraceae family, is distinguished by its leaves, which are abundant in proteins, polysaccharides, and flavonoids, positioning it as a novel feedstock. NAC transcription factors, exclusive to plant species, are crucial in regulating growth, development, and response to biotic and abiotic stress. However, extensive characterization of the NAC family within paper mulberry is lacking. In this study, 79 BpNAC genes were identified from the paper mulberry genome, with an uneven distribution across 13 chromosomes. A comprehensive, genome-wide analysis of BpNACs was performed, including investigating gene structures, promoter regions, and chromosomal locations. Phylogenetic tree analysis, alongside comparisons with Arabidopsis thaliana NACs, allowed for categorizing these genes into 16 subfamilies in alignment with gene structure and motif conservation. Collinearity analysis suggested a significant homologous relationship between the NAC genes of paper mulberry and those in Morus notabilis, Ficus hispida, Antiaris toxicaria, and Cannabis sativa. Integrating transcriptome data and Se content revealed that 12 BpNAC genes were associated with selenium biosynthesis. Subsequent RT-qPCR analysis corroborated the correlation between BpNAC59, BpNAC62 with sodium selenate, and BpNAC55 with sodium selenite. Subcellular localization experiments revealed the nuclear functions of BpNAC59 and BpNAC62. This study highlights the potential BpNAC transcription factors involved in selenium metabolism, providing a foundation for strategically breeding selenium-fortified paper mulberry.

Microflora structure and functional capacity in Tibetan kefir grains and selenium-enriched Tibetan kefir grains: A metagenomic analysis

Tibetan kefir grains (TKGs) are a complex protein-lipid-polysaccharide matrix composed of various microorganisms. Microorganisms have the benefit of being effective, secure, and controllable when used for selenium enrichment. In this study, selenium-enriched Tibetan kefir grains (Se-TKGs) were made, and the microbiology composition was analyzed through a metagenomic analysis, to explore the influence of selenium enrichment. The microbial composition of TKGs and Se-TKGs, as well as the probiotic species, quorum sensing system (QS) and functional genes were compared and evaluated. Lactobacillus kefiranofaciens was the most abundant microbial species in both communities. Compared with TKGs, Se-TKGs had a much higher relative abundance of acetic acid bacteria. Lactobacillus helveticus was the most common probiotic species both in TKGs and Se-TKGs. Probiotics with antibacterial and anti-inflammatory properties were more abundant in Se-TKGs. QS analysis revealed that Se-TKGs contained more QS system-associated genes than TKGs. Moreover, Kyoto Encyclopedia of Genes and Genomes analysis revealed that the pathway for human disease ko01501 had the greatest relative abundance in both TKGs and Se-TKGs. Compared with TKGs, Se-TKGs demonstrated a greater relative abundance of different drug resistance-related metabolic pathways. Additionally, linear discriminant analysis effect size was used to examine the biomarkers responsible for the difference between the two groups. In this study, we focused on the microbiological structure of TKGs and Se-TKGs, with the aim of establishing a foundation for a more thorough investigation of Se-TKGs and providing a basis for exploring potential future use.

Brazil nut consumption reduces DNA damage in overweight type 2 diabetes mellitus patients

Type 2 diabetes mellitus (T2D) is a metabolic disease, which occurs largely due to unhealthy lifestyle. As oxidative stress is believed to promote T2D, by inducing damage to lipids, proteins, and DNA, appropriate dietary interventions seem critical to prevent, manage, and even reverse this condition. Brazil nuts (Bertholletia excelsa, H.B.K.) are nature's richest source of selenium, a mineral that has shown several health benefits. Therefore, this study aims to assess the effects of selenium consumption, through Brazil nuts, on biochemical and oxidative stress parameters, and genomic instability in T2D patients. We recruited 133 patients with T2D, registered in the Integrated Clinics of the University of Southern Santa Catarina (Brazil). Participants consumed one Brazil nut a day for six months. Blood samples and exfoliated buccal cells were collected at the beginning and the end of the intervention. The glycemic profile, lipid profile, renal profile and hepatic profile, DNA damage and selenium content were evaluated. A total of 74 participants completed the intervention. Brazil nut consumption increased selenium and GSH levels, GPx, and CAT activity while DCF and nitrites levels decreased. Total thiols increased, and protein carbonyl and MDA levels decreased. Levels of baseline and oxidative DNA damage in T2D patients were significantly decreased, as well as the frequency of micronuclei and nuclear buds. The fasting glucose levels, HDL and LDL cholesterol, and GGT levels that increased significantly in patients with type 2 diabetes were significantly reduced with nut consumption. Our results show an increase in antioxidant activity, along with reductions of protein and lipid oxidation as well as DNA damage, suggesting that Brazil nut consumption could be an ally in reducing oxidative stress and modulating the genomic instability in T2D patients.

The cardiomyopathy of cystic fibrosis: a modern form of Keshan disease

Introduction

We conducted a study to determine the prevalence of structural heart disease in patients with CF, the characteristics of a cardiomyopathy not previously described in this population, and its possible relationship with nutritional deficiencies in CF.

Methods

We studied 3 CMP CF patients referred for heart-lung transplantation and a prospective series of 120 adult CF patients. All patients underwent a clinical examination, blood tests including levels of vitamins and trace elements, and echocardiography with evaluation of myocardial strain. Cardiac magnetic resonance imaging (CMR) was performed in patients with CMP and in a control group. Histopathological study was performed on hearts obtained in transplant or necropsy.

Results

We found a prevalence of 10% (CI 4.6%-15.4%) of left ventricular (LV) dysfunction in the prospective cohort. Myocardial strain parameters were already altered in CF patients with otherwise normal hearts. Histopathological examination of 4 hearts from CF CMP patients showed a unique histological pattern of multifocal myocardial fibrosis similar to Keshan disease. Four of the five CF CMP patients undergoing CMR showed late gadolinium uptake, with a characteristic patchy pattern in 3 cases (p < 0.001 vs. CF controls). Selenium deficiency (Se < 60 µg/L) was associated with more severe LV dysfunction, higher prevalence of CF CMP, higher NTproBNP levels, and more severe pulmonary and digestive involvement.

Conclusion

10% of adults with CF showed significant cardiac involvement, with histological and imaging features resembling Keshan disease. Selenium deficiency was associated with the presence and severity of LV dysfunction in these patients.

Relationship between Serum Concentrations and Muscular Expressions of Selenoproteins on Selenium-Supplemented Insulin Resistance Mouse Model

Previously, insulin resistance and hepatic oxidative stress with increased expressions of glutathione peroxidase (GPx) 1 and selenoprotein P (SelP) were induced in NSY mice, a diabetic mouse model, by administrating a high fat diet (HFD) and seleno-L-methionine (SeMet) for 12 weeks. In this study we developed an analysis method for serum selenoproteins using LC-tandem mass spectrometry (LC-MS/MS) and investigated the effects of supplementary selenium on serum concentrations of selenoproteins as well as protein expression in skeletal muscle as a major insulin target tissue under the same experimental condition. The glucose area under the curves for oral glucose tolerance and insulin tolerance tests indicated that the HFD induced insulin resistance, whereas the treatment of SeMet + HFD showed insignificant promotion compared with the HFD-induced insulin resistance. Although the expressions of GPx1 in gastrocnemius and soleus were not significantly induced by supplementary SeMet nor HFD administration, the expressions of SelP in both skeletal muscles were significantly induced by the treatment of SeMet + HFD. There were also significant increases in serum concentrations of SelP by supplementary SeMet + HFD administration, whereas GPx3 was augmented by supplementary SeMet only. These results indicated that the HFD intake under the sufficient selenium status augmented the blood secretion of SelP, which may participate in the reduction of insulin sensitivity in skeletal muscles as well as liver or adipose tissues, and it is a better indicator of deterioration than GPx3 as it is a major selenoprotein in serum.

Appraising causal risk and protective factors for rheumatoid arthritis

Aims

Mendelian randomization (MR) is considered to overcome the bias of observational studies, but there is no current meta-analysis of MR studies on rheumatoid arthritis (RA). The purpose of this study was to summarize the relationship between potential pathogenic factors and RA risk based on existing MR studies.

Methods

PubMed, Web of Science, and Embase were searched for MR studies on influencing factors in relation to RA up to October 2022. Meta-analyses of MR studies assessing correlations between various potential pathogenic factors and RA were conducted. Random-effect and fixed-effect models were used to synthesize the odds ratios of various pathogenic factors and RA. The quality of the study was assessed using the Strengthening the Reporting of Observational Studies in Epidemiology using Mendelian Randomization (STROBE-MR) guidelines.

Results

A total of 517 potentially relevant articles were screened, 35 studies were included in the systematic review, and 19 studies were eligible to be included in the meta-analysis. Pooled estimates of 19 included studies (causality between 15 different risk factors and RA) revealed that obesity, smoking, coffee intake, lower education attainment, and Graves' disease (GD) were related to the increased risk of RA. In contrast, the causality contribution from serum mineral levels (calcium, iron, copper, zinc, magnesium, selenium), alcohol intake, and chronic periodontitis to RA is not significant.

Conclusion

Obesity, smoking, education attainment, and GD have real causal effects on the occurrence and development of RA. These results may provide insights into the genetic susceptibility and potential biological pathways of RA.

Rutin modified selenium nanoparticles reduces cell oxidative damage induced by H2O2 by activating Nrf2/HO-1 signaling pathway

Oxidative damage of neurons is one of the key pathological markers of Alzheimer's disease (AD), which eventually leads to neuronal apoptosis and loss. Nuclear factor E2-related factor 2 (Nrf2) is a key regulator of antioxidant response and is considered to be an important therapeutic target for neurodegenerative diseases. In this study, the selenated derivative of antioxidant rutin (Se-Rutin) was synthesized with sodium selenate (Na₂SeO₃) as raw material by a simple electrostatic-compound in situ selenium reduction method. The effects of Se-Rutin on H₂O₂ induced oxidative damage in Pheochromocytoma PC12 cells were evaluated by cell viability, apoptosis, reactive oxygen species level and the expression of antioxidant response element (Nrf2). The results showed that H₂O₂ treatment significantly increased the level of apoptosis and reactive oxygen species, while the level of Nrf2 and HO-1 decreased. However, Se-Rutin significantly reduced H₂O₂ induced apoptosis and cytotoxicity, and increased the expression of Nrf2 and HO-1, both of which were better than that of pure rutin. Therefore, the activation of Nrf2/HO-1 signaling pathway may be the basis of Se-Rutin's anti-oxidative damage to AD.

Essential Trace Element Status in Systemic Lupus Erythematosus: a Meta-analysis Based on Case-Control Studies

The homeostasis of trace elements is essential to regulate different aspects of the immune system and might play important roles in systemic lupus erythematosus (SLE). However, epidemiological evidences that compared the level of essential trace elements in SLE patients and healthy controls (HCs) did not reach a consensus. This was the first meta-analysis to comprehensively assess the level of zinc (Zn), copper (Cu), iron (Fe), and selenium (Se) in SLE and HCs. PubMed, Embase, and Web of Science were systematically searched until April 2022 to find relevant literatures. The PRISMA statement 2020 was followed to make sure the quality of reporting a meta-analysis. The outcomes were assessed by pooled standardized mean difference (SMD) and 95% confidence intervals (CIs). Finally, eleven articles with 1262 subjects were included in the meta-analysis. Significantly lower levels of Zn (SMD = -0.709; 95% CI: -1.173, -0.245; P = 0.003) and Fe (SMD = -1.783; 95% CI: -2.756, -0.809; P = 0.000) were found in SLE compared with HCs. Higher levels of Cu (SMD = 0.808; 95% CI: 0.234, 1.382; P = 0.006) were found in SLE patients. In addition, compared with HCs, Fe and Zn were lower in SLE patients in Asia and Cu was higher in SLE patients in Europe. However, no significant difference was observed in the level of Se (SMD = -0.251; 95% CI: -1.087, 0.586; P = 0.557). Above all, SLE patients exhibited lower Zn and Fe and increased Cu concentrations compared with HCs. Further studies are warranted to investigate the mechanism of Zn, Cu, and Fe in SLE patients.

Review on the health-promoting effect of adequate selenium status

Selenium is an essential microelement involved in various biological processes. Selenium deficiency increases the risk of human immunodeficiency virus infection, cancer, cardiovascular disease, and inflammatory bowel disease. Selenium possesses anti-oxidant, anti-cancer, immunomodulatory, hypoglycemic, and intestinal microbiota-regulating properties. The non-linear dose-response relationship between selenium status and health effects is U-shaped; individuals with low baseline selenium levels may benefit from supplementation, whereas those with acceptable or high selenium levels may face possible health hazards. Selenium supplementation is beneficial in various populations and conditions; however, given its small safety window, the safety of selenium supplementation is still a subject of debate. This review summarizes the current understanding of the health-promoting effects of selenium on the human body, the dietary reference intake, and evidence of the association between selenium deficiency and disease.

Electrogenerated copper selenide with positive charge to efficiently capture and combat drug-resistant bacteria for wound healing

Limited by the effective radius of metal ion release, higher concentrations of antibacterial agents are usually required to achieve satisfactory efficacy. Unfortunately, the potential cytotoxicity of metal ions limits the administered dose, which greatly hinders the widespread use of metal antibacterial agents. In this work, we used a convenient electrochemical method to prepare electropositive copper selenide (CuSe) nanosheets gathered from the cathode. Under physiological conditions, trace amounts of electrolytic CuSe (E-CuSe, 1 μg mL^-1) could electrostatically bind to bacterial membranes and almost completely kill three resistant bacteria models (10⁶ colony forming unit (CFU) mL^-1). The extremely low effective dose of E-CuSe reaches a new benchmark in comparison with copper-based nanomaterials in other related studies. In addition, due to the reasonable coupling of selenium and copper, the as-prepared E-CuSe nanosheets exhibit lower cytotoxicity compared to copper oxide. As expected, the E-CuSe performed well in resistant bacteria-infected wound healing in rats, rapidly promoting wound tissue with a diameter of about 1 cm recovery within 7 days. Transcriptome analysis revealed the E-CuSe mainly acted on the membrane transport and DNA synthesis systems of bacterial cells. This work presents an efficient and in-depth paradigm for the scientific design and inactivation mechanism of metal antibacterial agents.

Selenium, selenoproteins and cancer of the thyroid

Selenium is an essential mineral element with important biological functions for the whole body through incorporation into selenoproteins. This element is highly concentrated in the thyroid gland. Selenoproteins provide antioxidant protection for this tissue against the oxidative stress caused by free radicals and contribute, via iodothyronine deiodinases, to the metabolism of thyroid hormones. It is known that oxidative stress plays a major role in carcinogenesis and that in recent decades there has been an increase in the incidence of thyroid cancer. The anti-carcinogenic action of selenium, although not fully understood, is mainly attributable to selenoproteins antioxidant properties, and to the ability to modulate cell proliferation (cell cycle and apoptosis), energy metabolism, and cellular immune response, significantly altered during tumorigenesis. Researchers have suggested that different forms of selenium supplementation may be beneficial in the prevention and treatment of thyroid cancer; however, the studies have several methodological limitations. This review is a summary of the current knowledge on how selenium and selenoproteins related to thyroid cancer.

Nano selenium-enriched probiotic Lactobacillus enhances alum adjuvanticity and promotes antigen-specific systemic and mucosal immunity

Nano selenium-enriched probiotics have been identified to improve immune responses, such as alleviating inflammation, antioxidant function, treatment of tumors, anticancer activity, and regulating intestinal flora. However, so far, there is little information on improving the immune effect of the vaccine. Here, we prepared nano selenium-enriched Levilactobacillus brevis 23017 (SeL) and heat-inactivated nano selenium-enriched L. brevis 23017 (HiSeL) and evaluated their immune enhancing functions on the alum-adjuvanted, inactivated Clostridium perfringens type A vaccine in mouse and rabbit models, respectively. We found that SeL enhanced immune responses of the vaccine by inducing a more rapid antibody production, eliciting higher immunoglobulin G (IgG) antibody titers, improving secretory immunoglobulin A (SIgA) antibody level and cellular immune response, and regulating Th1/Th2 immune response, thus helping to induce better protective efficacy after challenge. Moreover, we confirmed that the immunoenhancement effects are related to regulating oxidative stress, cytokine secretion, and selenoprotein expression. Meanwhile, similar effects were observed in HiSeL. In addition, they show enhanced humoral immune response at 1/2 and 1/4 standard vaccine doses, which confirms their prominent immune enhancement effect. Finally, the effect of improving vaccine immune responses was further confirmed in rabbits, which shows that SeL stimulates the production of IgG antibodies, generates α toxin-neutralizing antibodies rapidly, and reduces the pathological damage to intestine tissue. Our study demonstrates that nano selenium-enriched probiotics improve the immune effect of the alum adjuvants vaccine and highlight its potential usage in remedying the disadvantages of alum adjuvants.

Excess selenium intake is associated with microalbuminuria in female but not in male among adults with obesity: Results from NHANES 2009-2018

Introduction

Selenium is a critical trace element with antioxidant activities that has been related to the preservation of kidney function. Few studies, however, have looked at the effects of excess selenium on kidneys. The purpose of the present study was performed to investigate the relationship between dietary selenium intake and the prevalence of microalbuminuria in American adults with obesity.

Methods

A total of 8,547 participants with obesity in the National Health and Nutrition Examination Survey (NHANES) with the age of 19 years or older were included in the present study. Multivariable regression and subgroup analyses were performed to examine the association between dietary selenium and microalbuminuria in the two genders, separately. A selenium intake above the median was defined as high selenium intake.

Results

Dietary selenium intake was significantly higher in men compared to women (139.49 μg/day vs. 101.06 μg/day; P < 0.0001). Among female participants, the prevalence of microalbuminuria was significantly higher in participants with a high selenium intake compared with those without a high selenium intake (13.82 vs. 9.96%; P = 0.008), whereas this difference did not exist in male participants (10.79 vs. 11.97%; P = 0.40). Dietary selenium is not significantly correlated with microalbuminuria (P = 0.68) in the male population, whereas each 1 μg/day of increase in selenium consumption was independently associated with a 6h higher risk of microalbuminuria (OR = 1.006; 95% CI, 1.001-1.011, P = 0.01) in females.

Conclusion

According to our research, excessive selenium consumption is positively correlated with microalbuminuria in females with obesity, but not in males with obesity.

Multifunctional inorganic biomaterials: New weapons targeting osteosarcoma

Osteosarcoma is the malignant tumor with the highest incidence rate among primary bone tumors and with a high mortality rate. The anti-osteosarcoma materials are the cross field between material science and medicine, having a wide range of application prospects. Among them, biological materials, such as compounds from black phosphorous, magnesium, zinc, copper, silver, etc., becoming highly valued in the biological materials field as well as in orthopedics due to their good biocompatibility, similar mechanical properties with biological bones, good biodegradation effect, and active antibacterial and anti-tumor effects. This article gives a comprehensive review of the research progress of anti-osteosarcoma biomaterials.

Preparation, characteristic and anti-inflammatory effect of selenium nanoparticle-enriched probiotic strain Enterococcus durans A8-1

BACKGROUND

Elemental selenium, a new type of selenium supplement, can be biosynthesized via microorganisms. This study is to characterize a patent probiotic bacteria Enterococcus durans A8-1, capable of reducing selenite (Se⁶⁺ or Se⁴⁺) to elemental selenium (Se⁰) with the formation of Se nanoparticles (SeNPs).

METHODS

The selenium nanoparticles synthesized from A8-1 were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and X-ray photoelectron energy (XPS). The Caco2 cells were used to investigate the effects of Se-enriched A8-1 on the viability, membrane integrity, and the regulation of cellular inflammation through MTT and ELISA assays. The selenium-enriched metabolic function of A8-1 was analyzed by transcriptome sequencing.

RESULTS

E. durans A8-1 has the ability to synthesize intracellular SeNPs that are incubated with 60 mg/L sodium selenite for 18 h at 37 °C with 7 % inoculum under aerobic conditions. The selenium-enriched transformation rate increased to 43.46 %. After selenium enrichment, there were no significant morphological changes in E. durans A8-1 cells. The cells also exhibited no cytotoxicity when incubated with Caco-2 cells, and increased cellular proliferation. Furthermore, Se-enriched A8-1 cells antagonize the adhesion of S. typhimurium ATCC14028 onto the surface of Caco-2 cells protecting cell membrane integrity and was assessed by measuring LDH and AKP activities (P <0.001, P <0.001). Moreover, Se-enriched A8-1 could protect Caco-2 cells from inflammation induced by lipopolysaccharide and help the cells alleviate the inflammation through the reduced expression of cytokine IL-8 (P = 0.0012, P <0.001) and TNF-α (P <0.001, P <0.001). Based on transcriptome sequencing in Se-enriched E. durans A8-1 cells, there were 485 up-regulated genes and 322 down-regulated genes (P_adj < 0.05). There were 19 predicted up-regulated genes that are highly related to the potential selenium metabolism pathway, which focuses on the transportation of Na₂SeO₃ by membrane proteins, and gradually reduces Na₂SeO₃ to elemental selenium aggregates that are deposited onto the membrane surface via the intracellular redox response.

CONCLUSION

E. durans A8-1 could convert extracellular selenite into intracellular biological SeNPs via redox pathway with strong selenium-rich metabolism, and its biological SeNPs have anti-inflammatory properties, which have the potential for the development of composite selenium nanomaterials and can be further studied for the function of SeNPs with potential applications.

Comparison of an Artificial Neural Network and a Response Surface Model during the Extraction of Selenium-Containing Protein from Selenium-Enriched Brassica napus L

In this study, the extraction conditions for selenium-enriched rape protein (SEP) were optimized by applying a response surface methodology (RSM) and artificial neural network (ANN) model, and then, the optimal conditions were obtained using a genetic algorithm (GA). Then, the antioxidant power of the SEP was examined by using the DPPH, ABTS, and CCK-8 (Cell Counting Kit-8), and its anticancer activities were explored by conducting a cell migration test. The results showed that compared with the RSM model, the ANN model was more accurate with a higher determination coefficient and fewer errors when it was applied to optimize the extraction method. The data obtained for SEP using a GA were as follows: the extraction temperature was 59.4 °C, the extraction time was 3.0 h, the alkaline concentration was 0.24 mol/L, the liquid-to-material ratio was 65.2 mL/g, and the predicted content of protein was 58.04 mg/g. The protein was extracted under the conditions obtained by the GA; the real content of protein was 57.69 mg/g, and the protein yield was 61.71%. Finally, as the concentration of the selenium-containing protein increased, it showed increased ability in scavenging free radicals and was influential in inhibiting the proliferation and migration of HepG2 cells.

Nuts as a Dietary Enrichment with Selected Minerals-Content Assessment Supported by Chemometric Analysis

Nuts used as a snack and meal accompaniment supply plant protein and fatty acids that are beneficial for human health; however, they can also provide minerals. The aim of this study was to determine the content of selected elements that are often deficient in the diet (calcium, potassium, magnesium, selenium, and zinc) in nuts and determine whether they can be used to supplement deficiencies in the diet. In this study, we analyzed 10 types of nuts (n = 120 samples) that are consumed and available for sale in Poland. The content of calcium, magnesium, selenium, and zinc was determined by the atomic absorption spectrometry method, and flame atomic emission spectrometry was used for determination of potassium contents. The highest median calcium content was found in almonds (2825.8 mg/kg), the highest potassium content in pistachio nuts (15,730.5 mg/kg), the highest magnesium and selenium contents in Brazil nuts (10,509.2 mg/kg and 4348.7 μg/kg, respectively), and the highest zinc content in pine nuts (72.4 mg/kg). All the tested nuts are a source of magnesium, eight types of tested nuts are a source of potassium, six nut types are a source of zinc, and four nut types are a source of selenium; however, among the tested nuts, only almonds can be considered a source of calcium. Moreover, we found that selected chemometric methods can be useful in the classification of nuts. The studied nuts are valuable products that can be used to supplement the diet with selected minerals and can therefore be labelled as functional products crucial for disease prevention.

Exploring nanoselenium to tackle mutated SARS-CoV-2 for efficient COVID-19 management

Despite ongoing public health measures and increasing vaccination rates, deaths and disease severity caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its new emergent variants continue to threaten the health of people around the world. Therefore, there is an urgent need to develop novel strategies for research, diagnosis, treatment, and government policies to combat the variant strains of SARS-CoV-2. Since the state-of-the-art COVID-19 pandemic, the role of selenium in dealing with COVID-19 disease has been widely discussed due to its importance as an essential micronutrient. This review aims at providing all antiviral activities of nanoselenium (Nano-Se) ever explored using different methods in the literature. We systematically summarize the studied antiviral activities of Nano-Se required to project it as an efficient antiviral system as a function of shape, size, and synthesis method. The outcomes of this article not only introduce Nano-Se to the scientific community but also motivate scholars to adopt Nano-Se to tackle any serious virus such as mutated SARS-CoV-2 to achieve an effective antiviral activity in a desired manner.

Selenium: An Antioxidant with a Critical Role in Anti-Aging

Aging is characterized by an imbalance between damage inflicted by reactive oxygen species (ROS) and the antioxidative defenses of the organism. As a significant nutritional factor, the trace element selenium (Se) may remodel gradual and spontaneous physiological changes caused by oxidative stress, potentially leading to disease prevention and healthy aging. Se is involved in improving antioxidant defense, immune functions, and metabolic homeostasis. An inadequate Se status may reduce human life expectancy by accelerating the aging process or increasing vulnerability to various disorders, including immunity dysfunction, and cancer risk. This review highlights the available studies on the effective role of Se in aging mechanisms and shows the potential clinical implications related to its consumption. The main sources of organic Se and the advantages of its nanoformulations were also discussed.

Sex-specific relationship between blood selenium levels and platelet count in a large cohort representative of the United States population

While several small studies have found that selenium deficiency is associated with low platelet counts, they lack generalizability. We used data from the National Health and Nutrition Examination Surveys collected over a 12-year period. We examined the relationship between selenium quartiles and platelet count using survey-weighted linear regression models adjusting for age, sex, race, household income to poverty threshold income, highest education attainment, smoking status, red blood cell folate, and body mass index. Of the 21,764 participants, 51% were females, 23% African Americans, and 25% were >65 years of age. Mean (SD) platelet count was 243(64) 10⁹/L and selenium was 183(32) µg/L. Women had significantly higher platelet count but lower selenium levels than men (258 vs. 227 10⁹/L and 181 vs. 185 µg/L respectively; both P < 0.0001). In adjusted analysis, participants in the highest selenium quartile had 8.0x10⁹/L higher platelet count as compared to those in the lowest selenium quartile (95%CI = 4.1 to 11.9; P < 0.0001). Gender modified the relationship between the two; although there was no difference in women, platelet count was higher in the highest than the lowest selenium quartile in men (interaction p-value = 0.001). These findings highlight the importance of selenium and gender in platelet biology which needs to be explored.

Transcriptomic analysis reveals the effects of maternal selenium deficiency on placental transport, hormone synthesis, and immune response in mice

Selenium deficiency has been considered to increase the risk of gestational complications. Our previous work showed that maternal selenium deficiency suppressed proliferation, induced autophagy dysfunction and apoptosis in the placenta of mice. However, other effects of maternal selenium deficiency on the placenta and the underlying mechanisms remain unclear. In the present study, dietary selenium deficiency in dams significantly suppressed glutathione peroxidase (GSH-Px) activity, total antioxidant capacity (T-AOC), and increased malondialdehyde (MDA) content in the placentae, confirming the oxidative stress in the placenta. By transcriptome sequencing analysis, the DEGs were involved in many biological processes, including ion transport, lipid metabolic process, immune response, transmembrane transport, and others. According to the KEGG analysis, the DEGs were primarily enriched in metabolic pathways, PI3K-Akt signaling pathway, and others. Among these, the steroid hormone biosynthesis pathway enriched the most DEGs. Hsd3b1, an ER enzyme involved in progesterone synthesis, was validated downregulated. Consistently, the progesterone content in the serum of the selenium-deficient group was decreased. Ion transporters and transmembrane transporters, such as Heph, Trf, Slc39a8, Slc23a1, Atp7b, and Kcnc1, were reduced in the selenium-deficient placentae. Immune response-related genes, including Ccl3, Ccl8, Cxcl10, and Cxcl14, were increased in the selenium-deficient placentae, along with an increase in macrophage number. These results suggested that maternal selenium deficiency may impair progesterone biosynthesis, reduce nutrient transporters expression, and promote immune response by increasing the oxidative stress of the placentae. This present study provides a novel insight into the possible cause of placenta disorder during pregnancy.

Selenium concentration is associated with occurrence and diagnosis of three cardiovascular diseases: A systematic review and meta-analysis

BACKGROUND

Selenium (Se) is a vital trace element playing its biological functions through selenoprotein, which has been implicated in various physiological and pathological processes. A growing number of studies indicate that low Se increases the risk of cardiovascular diseases (CVDs). This meta-analysis aimed to compare and analyze differences in Se levels between patients with heart failure (HF), myocardial infarction (MI), coronary heart disease (CHD), and healthy people. This will provide ideas with the potential to improve clinical intervention and prevention of CVDs.

METHODS

The PubMed, Embase, Chinese National Knowledge Infrastructure (CNKI) and Chinese Biomedical databases were systematically searched for relevant publications until November 20, 2020. The following combination keywords were used: "(heart failure disease OR myocardial infarction OR coronary heart disease) AND (selenium OR Se)". The identified studies were screened against inclusion and exclusion criteria and extracted data were analyzed using RevMan5.3 and State 16.0 software.

RESULTS

A total of 49 eligible studies (including 61 cohorts) were obtained. Results of the meta-analysis showed that there was a significant difference in Se levels between HF, MI, CHD patients and healthy people. The standard mean difference (SMD) level of Se in HF patients [SMD = -0.98, 95 % CI (-1.34, -0.62)], MI patients [MI: SMD = -3.46, 95 % CI (-4.43, -2.85)], and CHD patients [CHD: SMD = -0.47, 95 % CI (-0.64, -0.28)] were all significantly lower compared to healthy controls. Analysis of the correlation between Se level and publication year showed that SMD of Se levels in HF and controls was positively correlated with time. Se level was found to be a good diagnostic marker of MI (AUC = 0.7107, P = 0.0167, Sensitivity = 77.27 %, Specificity = 72.73 %).

CONCLUSIONS

This meta-analysis shows that Se levels in patients with HF, MI, and CHD are generally lower compared with healthy controls. However, due to the small number of included studies, further studies are needed to confirm the present results.

Minerals and Cancer: Overview of the Possible Diagnostic Value

Simple Summary

Minerals are important but often overlooked compounds that are required for a variety of cellular biochemical processes and pathways that regulate cell proliferation. Their dietary imbalance, which is becoming more common in the diets of industrialized countries, is linked to an increased risk of cancer. The current review will present some of the most important minerals for human physiology and evaluate their potential application as cancer biomarkers.

Abstract

Cancer is the second leading cause of death worldwide and is expected to increase by one-third over the next two decades, in parallel with the growing proportion of the elderly population. Treatment and control of cancer incidence is a global issue. Since there is no clear way to prevent or cure this deadly malignancy, diagnostic, predictive, and prognostic markers for oncological diseases are of great therapeutic value. Minerals and trace elements are important micronutrients for normal physiological function of the body. They are abundant in natural food sources and are regularly included in dietary supplements whereas highly processed industrial food often contains reduced or altered amounts of them. In modern society, the daily intake, storage pools, and homeostasis of these micronutrients are dependent on certain dietary habits and can be thrown out of balance by malignancies. The current work summarizes the data on minerals and trace elements associated with abnormal accumulation or depletion states in tumor patients and discusses their value as potential tumor-associated biomarkers that could be introduced into cancer therapy.

The Effects of Selenium on Bone Health: From Element to Therapeutics

Osteoporosis, characterized by low bone mass and a disruption of bone microarchitecture, is traditionally treated using drugs or lifestyle modifications. Recently, several preclinical and clinical studies have investigated the effects of selenium on bone health, although the results are controversial. Selenium, an important trace element, is required for selenoprotein synthesis and acts crucially for proper growth and skeletal development. However, the intake of an optimum amount of selenium is critical, as both selenium deficiency and toxicity are hazardous for health. In this review, we have systematically analyzed the existing literature in this field to determine whether dietary or serum selenium concentrations are associated with bone health. In addition, the mode of administration of selenium as a supplement for treating bone disease is important. We have also highlighted the importance of using green-synthesized selenium nanoparticles as therapeutics for bone disease. Novel nanobiotechnology will be a bridgehead for clinical applications of trace elements and natural products.

Association of selenium levels with the prevention and control of Keshan disease: A cross-sectional study

PURPOSE

The prevalence of Keshan disease (KD) is low and has reached controlled or eliminated levels even in counties that had a high KD prevalence in the past. Few nationwide surveys on selenium levels in KD areas have been conducted in the past 2 decades. We conducted a cross-sectional study to investigate the selenium levels and their association with KD control and prevention in areas where KD is prevalent.

METHODS

We collected 2143 human-hair, 698 soil, 701 rice, 607 flour, 521 corn, and 330 other-food samples from 49 counties with KD and 19 non-KD counties of nine KD provinces of China. The selenium content of samples was examined with hydride generation atomic fluorescence spectrometry. The difference in selenium levels between the KD and non-KD areas was analyzed. Cochran-Armitage trend tests were used to evaluate the association between selenium levels and KD control.

RESULTS

The selenium levels in human hair, soil, staple foods, and other foods in the KD areas (0.2996 mg/kg, 0.1380 mg/kg, 0.0190 mg/kg and 0.0076 mg/kg, respectively) were lower than those in the non-KD areas (0.3700 mg/kg, 0.1930 mg/kg, 0.0240 mg/kg and 0.0165 mg/kg, respectively). The Cochran-Armitage tests showed that there was a trend for the selenium standard ratio in the counties to increase in the order of KD uncontrolled, to controlled, to eliminated (Z = 2.229, P < 0.05).

CONCLUSION

The residents in the KD areas were found to be selenium-deficient. Improving the supply of staple foods containing selenium levels exceeding 0.025 mg/kg and abundant foodstuffs might contribute to KD control and prevention.

Trace Element Selenium Effectively Alleviates Intestinal Diseases

Selenium (Se) is an essential trace element in the body. It is mainly used in the body in the form of selenoproteins and has a variety of biological functions. Intestinal diseases caused by chronic inflammation are among the most important threats to human health, and there is no complete cure at present. Due to its excellent antioxidant function, Se has been proven to be effective in alleviating intestinal diseases such as inflammatory bowel diseases (IBDs). Therefore, this paper introduces the role of Se and selenoproteins in the intestinal tract and the mechanism of their involvement in the mediation of intestinal diseases. In addition, it introduces the advantages and disadvantages of nano-Se as a new Se preparation and traditional Se supplement in the prevention and treatment of intestinal diseases, so as to provide a reference for the further exploration of the interaction between selenium and intestinal health.

Nutrition and nonmelanoma skin cancers

Nonmelanoma skin cancer (NMSC), the most widely diagnosed cancer in the United States, is rising in incidence despite public health and educational campaigns that highlight the importance of sun avoidance. It is,therefore, important to establish other modifiable risk factors that may be contributing to this increase. There is a growing body of evidence in the literature suggesting certain nutrients may have protective or harmful effects on NMSC. We review the current literature on nutrition and its effect on NMSC with a focus on dietary fat, vitamin A, nicotinamide, folate, vitamin C, vitamin D, vitamin E, polyphenols, and selenium.

Cyano- and Ketone-Containing Selenoesters as Multi-Target Compounds against Resistant Cancers

Simple Summary

The search for novel anticancer agents has been the hot topic of interest in cancer research, due to the phenomenon of multidrug resistance (MDR) in cancer that can make cancer cells resistant to the current available chemotherapeutic agents. In this context, we have designed, synthesized, and biologically evaluated 15 novel selenoesters, with the aim to explore their activity against resistant cancer cell lines. Some of these described selenocompounds showed noteworthy cytotoxicity and selectivity, the ability to inhibit the ABCB1 efflux pump, the capacity to modulate the ATPase activity of this pump, the capability to trigger apoptotic events, the ability to interact in a synergistic manner with doxorubicin in resistant cancer cells, and the power to promote wound healing. Consequently, these results validate the design of these selenocompounds and justify further research to evaluate the possibilities of these compounds to be used in the future in the fight against resistant cancers.

Abstract

Fifteen selenocompounds, comprising of eight ketone-containing selenoesters (K1–K8, also known as oxoselenoesters) and seven cyano-containing selenoesters (N1–N7, known also as cyanoselenoesters), have been designed, synthesized, and evaluated as novel anticancer agents. These compounds are derivatives of previously reported active selenoesters and were prepared following a three-step one-pot synthetic route. The following evaluations were performed in their biological assessment: cytotoxicity determination, selectivity towards cancer cells in respect to non-cancer cells, checkerboard combination assay, ABCB1 inhibition and inhibition of ABCB1 ATPase activity, apoptosis induction, and wound healing assay. As key results, all the compounds showed cytotoxicity against cancer cells at low micromolar concentrations, with cyanoselenoesters being strongly selective. All of the oxoselenoesters, except K4, were potent ABCB1 inhibitors, and two of them, namely K5 and K6, enhanced the activity of doxorubicin in a synergistic manner. The majority of these ketone derivatives modulated the ATPase activity, showed wound healing activity, and induced apoptosis, with K3 being the most potent, with a potency close to that of the reference compound. To summarize, these novel derivatives have promising multi-target activity, and are worthy to be studied more in-depth in future works to gain a greater understanding of their potential applications against cancer.

Genetically determined selenium concentrations and risk for autoimmune diseases

OBJECTIVE

Observational epidemiologic studies have reported a relationship between selenium status and risk for autoimmune diseases. However, the associations are susceptible to confounding or reverse causality. Thus, the aim of this study was to investigate the potential causal associations of selenium concentrations with the risk for common autoimmune diseases using a two-sample Mendelian randomization (MR) design.

METHODS

A meta-analysis of genome-wide association studies (GWASs) of selenium among 9639 individuals of European ancestry was used to identify genetic instruments. Summary statistics of systemic lupus erythematosus, rheumatoid arthritis, and inflammatory bowel disease were obtained from publicly available GWASs, respectively. We conducted MR study using the inverse-variance weighted method, supplemented with weighted median and likelihood-based methods as sensitivity analysis. Cochran Q test and MR-Egger regression were used to detect heterogeneity and potential directional pleiotropy. MR-Pleiotropy RESidual Sum and Outlier test was used to identify outlier single-nucleotide polymorphisms.

RESULTS

Genetically predicted high selenium level was associated with a decreased risk for SLE (odds ratio, 0.85; 95% confidence interval, 0.77-0.93; P = 0.001) per natural log-transformed selenium concentrations, with similar results in sensitivity analyses. No evidence of heterogeneity, pleiotropy, or outlier single-nucleotide polymorphisms were detected (all P > 0.05). However, genetically determined selenium concentrations may be not associated with risk for rheumatoid arthritis or inflammatory bowel disease in the primary analysis and subsequent sensitivity analyses.

CONCLUSIONS

The present study suggested a protective role of selenium on the risk for systemic lupus erythematosus. Further studies are warranted to elucidate the underlying mechanisms.

Loss of Selenov predisposes mice to extra fat accumulation and attenuated energy expenditure

Selenoprotein V (SELENOV) is a new and the least conserved member of the selenoprotein family. Herein we generated Selenov knockout (KO) mice to determine its in vivo function. The KO led to 16-19% increases (P < 0.05) in body weight that were largely due to 54% higher (P < 0.05) fat mass accumulation, compared with the wild-type (WT) controls. The extra fat accumulation in the KO mice was mediated by up-regulations of genes and proteins involved in lipogenesis (Acc, Fas, Dgat, and Lpl; up by 40%-1.1-fold) and down-regulations of lipolysis (Atgl, Hsl, Ces1d, and Cpt1a; down by 36-89%) in the adipose tissues. The KO also decreased (P < 0.05) VO₂ consumption (14-21%), VCO₂ production (14-16%), and energy expenditure (14-23%), compared with the WT controls. SELENOV and O-GlcNAc transferase (OGT) exhibited a novel protein-protein interaction that explained the KO-induced decreases (P < 0.05) of OGT protein (15-29%), activity (33%), and function (O-GlcNAcylation, 10-21%) in the adipose tissues. A potential cascade of SELENOV-OGT-AMP-activated protein kinase might serve as a central mechanism to link the biochemical and molecular responses to the KO. Overall, our data revealed a novel in vivo function and mechanism of SELENOV as a new inhibitor of body fat accumulation, activator of energy expenditure, regulator of O-GlcNAcylation, and therapeutic target of such related disorders.

Fish Consumption: A Review of Its Effects on Metabolic and Hormonal Health

Dietary habits are a major determinant of the risk of chronic disease, particularly metabolic and endocrine disorders. Fish as a food group are a unique source of nutrients with metabolic and hormonal importance including omega-3 fatty acids, iodine, selenium, vitamin D, taurine and carnitine. Fish are also a source of high quality protein and have in general low caloric density. The impact of these nutrients on cardiovascular risk has been extensively reviewed, but the impact of fish on the broader field of endocrine and metabolic health is sometimes not sufficiently appreciated. This article aimed to summarize the impact the effect of regular fish consumption on conditions like the metabolic syndrome, obesity, diabetes, hypothyroidism, polycystic ovary syndrome and the menopausal transition, which are in and of themselves significant causes of morbidity and mortality worldwide. The review revealed that scientific evidence from food science, translational research, epidemiologic studies and interventional trials shows that regular fish consumption has a positive impact on thyroid homeostasis, facilitates maintenance of a healthy body weight, reduces the magnitude of age-associated increases in blood pressure, improves glucose homeostasis helping prevent diabetes and the metabolic syndrome, and has a positive impact on muscle mass preservation among the elderly. These effects are mediated by multiple mechanisms, only some of which have been identified. For most of these effects it holds true that the potential benefits are more substantial when baseline fish consumption is low.

Food Sources of Selenium and Its Relationship with Chronic Diseases

Selenium (Se) is an essential micronutrient for mammals, and its deficiency seriously threatens human health. A series of biofortification strategies have been developed to produce Se-enriched foods for combating Se deficiency. Although there have been some inconsistent results, extensive evidence has suggested that Se supplementation is beneficial for preventing and treating several chronic diseases. Understanding the association between Se and chronic diseases is essential for guiding clinical practice, developing effective public health policies, and ultimately counteracting health issues associated with Se deficiency. The current review will discuss the food sources of Se, biofortification strategies, metabolism and biological activities, clinical disorders and dietary reference intakes, as well as the relationship between Se and health outcomes, especially cardiovascular disease, diabetes, chronic inflammation, cancer, and fertility. Additionally, some concepts were proposed, there is a non-linear U-shaped dose-responsive relationship between Se status and health effects: subjects with a low baseline Se status can benefit from Se supplementation, while Se supplementation in populations with an adequate or high status may potentially increase the risk of some diseases. In addition, at supra-nutritional levels, methylated Se compounds exerted more promising cancer chemo-preventive efficacy in preclinical trials.

Bifunctional chiral selenium-containing 1,4-diarylazetidin-2-ones with potent antitumor activities by disrupting tubulin polymerization and inducing reactive oxygen species production

Organoselenium compounds have attracted growing interests as promising antitumor agents over recent years. Herein, four series of novel selenium-containing chiral 1,4-diarylazetidin-2-ones were asymmetrically synthesized and biologically evaluated for antitumor activities. Among them, compound 7 was found to be about 10-fold more potent than its prototype compound 1a, and compound 9a exhibited the most potent cytotoxicity against five human cancer cell lines, including a paclitaxel-resistant human ovarian cancer cell line A2780T, with IC₅₀ values ranging from 1 to 3 nM. Mechanistic studies revealed that compound 9a worked by disrupting tubulin polymerization, inducing reactive oxygen species (ROS) production, decreasing mitochondrial membrane potential, blocking the cell cycle in the G₂/M phase, inducing cellular apoptosis and suppressing angiogenesis. Additionally, compound 9a exhibited appropriate human-microsomal metabolic stability and physicochemical properties. Importantly, compound 9a was found to inhibit tumor growth effectively in a xenograft mice model with low toxicity profile, which rendered 9a a highly promising candidate for further pre-clinical development.

Factors Influencing Selenium Concentration in Community-Dwelling Patients with Type 2 Diabetes Mellitus

Selenium (Se) plays an important role in the pathogenesis of diabetes, and which factors affecting Se concentration in patients with type 2 diabetes mellitus (T2DM) are unknown. This study aimed to explore the factors influencing Se concentration in community-dwelling individuals with T2DM. A total of 176 patients with T2DM were involved, and their general information was collected through a self-designed questionnaire. Venous blood samples and hair samples were collected to detect Se concentration and biochemical parameters. Multiple linear regression and binary logistic regression analysis were used to analyze the factors influencing Se concentration in patients with T2DM. The factors influencing selenoprotein P concentration in patients with T2DM included alkaline phosphatase (β = - 1.373; 95% CI: 0.087-0.736; P = 0.012), systolic blood pressure (SBP; β = - 0.047; 95% CI: 0.930-0.978; P < 0.001), the duration of T2DM (β = - 0.074; 95% CI: 0.877-0.983; P = 0.011), and clinical complications (β = 1.237; 95% CI: 1.465-8.109; P = 0.005). The factors influencing glutathione peroxidase activity in patients with T2DM were creatinine (CREA; β = - 0.378; P < 0.001), uric acid (β = - 0.069; P = 0.009), body mass index (β = - 2.177; P = 0.002), SBP (β = - 0.275; P = 0.031), and medical payment (β = 29.160; P < 0.001). The factors influencing serum Se concentration in patients with T2DM were albumin (β = - 1.391; 95% CI: 0.065-0.959; P = 0.043) and CREA (β = - 1.482; 95% CI: 0.072-0.718; P = 0.012). The factors influencing hair Se concentration in patients with T2DM were smoking (β = - 1.151; 95% CI: 0.133-0.755; P = 0.010), drinking (β = 1.366; 95% CI: 1.191-12.909; P = 0.025), and hair dyeing (β = - 1.113; 95% CI: 0.124-0.867; P = 0.025). In conclusion, the Se concentration in patients with T2DM was mainly affected by liver and renal function. When liver and/or renal function was impaired, the Se concentration in patients with T2DM was decreased.

Agronomic iodine biofortification of leafy vegetables grown in Vertisols, Oxisols and Alfisols

Iodine deficiency disorders (IDD) in sub-Saharan African countries are related to low dietary I intake and generally combatted through salt iodisation. Agronomic biofortification of food crops may be an alternative approach. This study assessed the effectiveness of I biofortification of green vegetables (Brassica napus L and Amaranthus retroflexus L.) grown in tropical soils with contrasting chemistry and fertility. Application rates of 0, 5 and 10 kg ha^-1 I applied to foliage or soil were assessed. Leaves were harvested fortnightly for ~ 2 months after I application before a second crop was grown to assess the availability of residual soil I. A separate experiment was used to investigate storage of I within the plants. Iodine concentration and uptake in sequential harvests showed a sharp drop within 28 days of I application in all soil types for all I application levels and methods. This rapid decline likely reflects I fixation in the soil. Iodine biofortification increased I uptake and concentration in the vegetables to a level useful for increasing dietary I intake and could be a feasible way to reduce IDD in tropical regions. However, biofortification of green vegetables which are subject to multiple harvests requires repeated I applications.

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.

Exogenous proline enhances antioxidant enzyme activities but does not mitigate growth inhibition by selenate stress in tobacco BY-2 cells

Selenium (Se) causes oxidative damage to plants. Proline is accumulated as a compatible solute in plants under stress conditions and mitigates stresses. Selenate at 250 µM increased cell death and inhibited the growth of tobacco BY-2 cells while exogenous proline at 10 mM did not mitigate the inhibition by selenate. Selenate increased accumulation of Se and ROS and activities of antioxidant enzymes but not lipid peroxidation in the BY-2 cells. Proline increased Se accumulation and antioxidant enzyme activities but not either ROS accumulation or lipid peroxidation in the selenate-stressed cells. Glutathione (GSH) rather than ascorbic acid (AsA) mitigated the growth inhibition although both reduced the accumulation of ROS induced by selenate. These results indicate that proline increases both antioxidant enzyme activities and Se accumulation, which overall fails to ameliorate the growth inhibition by selenate and that the growth inhibition is not accounted for only by ROS accumulation. Abbreviations: APX: ascorbate peroxidase; AsA: ascorbic acid; BY-2: Bright Yellow-2; CAT: catalase; DAI: days after inoculation; DW: dry weight; FW: fresh weight; GSH: glutathione; ROS: reactive oxygen species.

Selenium and RNA Virus Interactions: Potential Implications for SARS-CoV-2 Infection (COVID-19)

SARS-CoV-2 is an RNA virus responsible for the COVID-19 pandemic that already claimed more than 340,000 lives worldwide as of May 23, 2020, the majority of which are elderly. Selenium (Se), a natural trace element, has a key and complex role in the immune system. It is well-documented that Se deficiency is associated with higher susceptibility to RNA viral infections and more severe disease outcome. In this article, we firstly present evidence on how Se deficiency promotes mutations, replication and virulence of RNA viruses. Next, we review how Se might be beneficial via restoration of host antioxidant capacity, reduction of apoptosis and endothelial cell damages as well as platelet aggregation. It also appears that low Se status is a common finding in conditions considered at risk of severe COVID-19, especially in the elderly. Finally, we present a rationale for Se use at different stages of COVID-19. Se has been overlooked but may have a significant place in COVID-19 spectrum management, particularly in vulnerable elderly, and might represent a game changer in the global response to COVID-19.

Total antioxidant status reduction conditioned by a serum selenium concentration decrease as a mechanism of the ultrasonographically measured brachial artery dilatation impairment in patients with arterial hypertension

The objective of the study was to determine the relationship between serum concentrations of selenium (SeS) and zinc (ZnS), total antioxidant status (TAS) and endothelial function assessed by ultrasonographic method of dilatation of the brachial artery in 141 hypertensive patients. Patients with SeS < median were characterized by a statistically significantly lower flow-mediated dilation (FMD) than patients with SeS ≥ median. Patients with TAS < median were characterized by a significantly lower FMD than patients with TAS ≥ median. Older age, higher BMI, male gender, higher blood total cholesterol, ischemic heart disease, smoking and lower SeS constitute independent predictors of inferior endothelial function, expressed in lower FMD values. Smoking is an independent predictor of lower TAS, and the use of β-blockers and higher serum selenium levels are independent predictors of higher TAS. In summary, a decrease in TAS should be considered as a mechanism of inferior endothelial function in hypertensive patients conditioned by a decrease in SeS.

Selenium level does not differ in blood but increased in cerebrospinal fluid in Parkinson's disease: a meta-analysis

Objective: Recent studies have found that selenium (Se) levels were associated with the risk of Parkinson's disease (PD), but the results were contradictory. Therefore, this meta-analysis was conducted to investigate the correlation between Se levels and PD.Methods: PubMed, Embase and Web of Science were searched published up to 28 October 2019. The differences between groups were analyzed by forest plots and results were pooled and assessed using a random-effect model. Standardized mean difference (SMD) and 95% confidence interval (CI) were used to assess the association between Se levels and the risk of PD. Subgroup analysis, meta-regression, and sensitivity analysis were also conducted. Publication bias was estimated using Begg's regression asymmetry test.Results: Finally, 12 articles involving 601 PD patients and 749 controls were included in this meta-analysis. The meta-analysis revealed a significantly higher cerebrospinal fluid (CSF) Se level in PD patients than those in controls (SMD = 1.22; 95%CI [0.05, 2.39]; p = 0.000). No publication bias was found.Conclusion: The meta-analysis indicated that CSF Se levels in PD patients were significantly higher than those in controls.

The inhibition of H1N1 influenza induced apoptosis by sodium selenite through ROS-mediated signaling pathways

The high variability of influenza viruses has made it more difficult for people to cope with influenza. When antigen transformation occurs, even new influenza without preventive vaccines may be produced, which poses a great threat to human health. Selenium is an essential trace element in humans and mammals, and has many biological activities. It has attracted people's research interest in recent years. In this study, MDCK cells were used as a model to observe the effect of sodium selenite on H1N1 influenza virus. Our research showed that sodium selenite (Na2SeO3) has an anti-influenza H1N1 virus effect, and the anti-viral effect of sodium selenite was further demonstrated by caspase-3, AKT, MAPK and p53 signaling pathways. The investigations of the mechanism revealed that the sodium selenite could block H1N1 influenza from infecting MDCK cells through inhibiting the production of ROS. The results demonstrate that selenium supplementation may provide a feasible approach to inhibit the infection of H1N1 influenza virus.

Selenium and RNA Virus Interactions: Potential Implications for SARS-CoV-2 Infection (COVID-19)

SARS-CoV-2 is an RNA virus responsible for the COVID-19 pandemic that already claimed more than 340,000 lives worldwide as of May 23, 2020, the majority of which are elderly. Selenium (Se), a natural trace element, has a key and complex role in the immune system. It is well-documented that Se deficiency is associated with higher susceptibility to RNA viral infections and more severe disease outcome. In this article, we firstly present evidence on how Se deficiency promotes mutations, replication and virulence of RNA viruses. Next, we review how Se might be beneficial via restoration of host antioxidant capacity, reduction of apoptosis and endothelial cell damages as well as platelet aggregation. It also appears that low Se status is a common finding in conditions considered at risk of severe COVID-19, especially in the elderly. Finally, we present a rationale for Se use at different stages of COVID-19. Se has been overlooked but may have a significant place in COVID-19 spectrum management, particularly in vulnerable elderly, and might represent a game changer in the global response to COVID-19.

Selenium and RNA Virus Interactions: Potential Implications for SARS-CoV-2 Infection (COVID-19)

SARS-CoV-2 is an RNA virus responsible for the COVID-19 pandemic that already claimed more than 340,000 lives worldwide as of May 23, 2020, the majority of which are elderly. Selenium (Se), a natural trace element, has a key and complex role in the immune system. It is well-documented that Se deficiency is associated with higher susceptibility to RNA viral infections and more severe disease outcome. In this article, we firstly present evidence on how Se deficiency promotes mutations, replication and virulence of RNA viruses. Next, we review how Se might be beneficial via restoration of host antioxidant capacity, reduction of apoptosis and endothelial cell damages as well as platelet aggregation. It also appears that low Se status is a common finding in conditions considered at risk of severe COVID-19, especially in the elderly. Finally, we present a rationale for Se use at different stages of COVID-19. Se has been overlooked but may have a significant place in COVID-19 spectrum management, particularly in vulnerable elderly, and might represent a game changer in the global response to COVID-19.

Common trace metals in rheumatoid arthritis: A systematic review and meta-analysis

INTRODUCTION

Environmental risk factors regrading rheumatoid arthritis (RA) have not been explored extensively. Selenium (Se), zinc (Zn) and copper (Cu) nutrients were reported to associate with RA, but the results were inconsistent. Therefore, we conduct present study to meta-analyze the relationship between serum Se, Zn and Cu and RA and review the potential mechanisms.

METHODS

PubMed, Web of Science and Cochrane Library were comprehensively searched till October 1, 2018 for pertinent studies. Standard mean differences (SMDs) and 95% confident intervals (CIs) were calculated according to random effects model.

RESULTS

Finally 41 literatures were included. Meta-analysis of 16 studies involving 806 RA patients and 959 health controls showed that serum Se (SMD = -1.04, 95% CI = -1.58 to -0.50) was decreased in RA patients, and 23 literatures with 1398 patients and 1299 controls reported serum Zn (SMD = -1.20, 95% CI = -1.74 to -0.67) was decreased. But serum Cu (SMD = 1.26, 95% CI = 0.63 to -1.89) was increased with 26 studies including 1723 patients and 1451 controls. Meta-regression reported that steroid use was positively related to serum level of Se in RA (β = 0.041, 95% CI = 0.002 to 0.079). Differences in serum Se, Zn and Cu between rheumatoid arthritis patients and controls were all related with the geographical distribution.

CONCLUSIONS

Patients with RA have significant decreased serum Se and Zn and increased serum Cu than health controls, suggesting potential roles of Se, Zn and Cu in the pathogenesis of RA. Patients and rheumatologist should give enough attention to the monitor of these elements during follow up.

Selenium and Health: An Update on the Situation in the Middle East and North Africa

Selenium (Se) is an important trace element that should be present in the diet of all age groups to provide an adequate intake. Se is incorporated in 25 known selenoproteins, which mediate the biological effects of Se including, immune response regulation, maintenance of thyroid function, antioxidant defense, and anti-inflammatory actions. A balanced intake of Se is critical to achieve health benefits because depending on its status, Se has been found to play physiological roles or contribute to the pathophysiology of various diseases including, neurodegenerative diseases, diabetes, cancer, and cardiovascular disorders. Se status and intake are very important to be known for a specific population as the levels of Se are highly variable among different populations and regions. In the Middle East and North African (MENA) region, very little is known about the status of Se. Studies available show that Se status is widely variable with some countries being deficient, some over sufficient, and some sufficient. This variability was apparent even within the same country between regions. In this review, we summarized the key roles of Se in health and disease and discussed the available data on Se status and intake among countries of the MENA region.