Multifaceted role of selenium in plant physiology and stress resilience: A review

Selenium (Se) is a naturally occurring element in both seleniferous and non-seleniferous soils. Plants absorb Se in a variety of ways, mainly as selenate (SeO42-), selenite (SeO32-), and organic compounds such as selenomethionine (SeMet). Selenium significantly impacts plant growth, development, and stress responses. It is a trace element that regulates many physiological and biochemical functions in plants, acts as an antioxidant, and increases plant resistance to abiotic stresses such as heavy metal toxicity, salinity, drought, and severe temperatures. Its beneficial effects depend on the dose and vary depending on the plant species and the environmental conditions. Several functions of Se have been thoroughly discussed in this review, with special attention given to the mechanisms of Se uptake, transport, accumulation, and metabolism. Plants use Se through its assimilation into amino acids (mostly selenocysteine and selenomethionine) and integration into proteins. These processes might have different effects depending on the Se concentration. Furthermore, Se has the potential to be a useful tool in sustainable agriculture, especially in regions where environmental stress is common. This is demonstrated by its ability to increase plant tolerance to various environmental stressors. Recent research shows that Se supplementation not only boosts plant resistance but also enhances secondary metabolite accumulation. Overall, this review concludes that Se plays a dual role in plant systems, acting as both a nutrient and a stress mitigator, and provides opportunities to optimize its use in sustainable agriculture by tailoring Se supplementation to maximize plant tolerance and productivity.

Selenium: The Toxicant for Pathogen and Pest but the Guardian of Soil and Crop

Selenium (Se) is an essential micronutrient for higher organisms and plays a beneficial role in plant growth and development. In recent years, there has been growing interest in the using of Se to enhance plant resilience, particularly in mitigating the effects of diseases and pests in agricultural systems. This review offers a comprehensive analysis of the sources and chemical forms of Se in soil, investigates the mechanisms of plant uptake and metabolism of different Se forms, and evaluates the physical and chemical inhibition of pathogens by various Se forms, as well as the role of Se in enhancing plant systemic resistance for crop protection. Additionally, we summarize current research on the role of Se in pest and disease control and explore potential future research directions, with a focus on integrating Se into sustainable agricultural practices. The insights presented in this review seek to establish a solid scientific foundation for Se-based approaches to pest control and emphasize its potential application in sustainable agriculture.

A novel approach for calculating food safety models and health risk assessments of potentially toxic elements (PTEs) in cow milk

This study introduces the Milk Quality Index (MQI), a novel metric for assessing milk quality that utilizes machine learning to enhance predictive accuracy. Lead (Pb) levels (318 ± 185 mg/kg) exceeded safety limits, with chromium (Cr), aluminum (Al), and selenium (Se) also raising concerns in raw cow milk from southwestern Iran. The MQI classified 80 % of samples as 'Fair' (range: 3.95-7.03, mean: 5.46), with random forest (RF) modeling confirming Se, calcium (Ca), and magnesium (Mg) as key contributors. Health risk assessments revealed elevated noncarcinogenic (HI50th = 2.48) and carcinogenic (TCR50th = 2.39E-4) risks in children. At the same time, arsenic (As) and nickel (Ni) had the greatest impact on the HI and TCR, respectively. Approximately 96.78 % of children and 98.96 % of adults may be exposed to elevated carcinogenic risks, respectively. This approach highlights the importance of PTE monitoring in milk to enhance food safety and protect public health.

Systematic Review of the Impact of COVID-19 on Healthcare Systems and Society-The Role of Diagnostics and Nutrition in Pandemic Response

The COVID-19 pandemic has revealed deep vulnerabilities in healthcare systems and public health preparedness. This systematic review examines the effectiveness of epidemiological procedures, the role of diagnostics, and the influence of nutritional status on immune function and disease severity. A total of 88 studies were analyzed, encompassing diagnostics, micronutrient deficiencies (notably vitamin D, C, E, zinc, and selenium), and the psychosocial impact of the pandemic. The results underscore the importance of integrated strategies-including accurate testing, preventive nutritional measures, and mental health support-in improving outcomes and societal resilience during global health crises. Unlike previous reviews that focused on isolated biomedical or public health elements, this study integrates diagnostics, immune-nutritional status, and psychosocial effects to present a comprehensive, multidimensional analysis of pandemic impact and preparedness.

Comparative Study on the Effects of Selenium-Enriched Yeasts with Different Selenomethionine Contents on Gut Microbiota and Metabolites

Selenium is an essential trace element for human health, but it mainly exists in an inorganic form that cannot be directly absorbed by the body. Brewer's yeast efficiently converts inorganic selenium into bioavailable organic selenium, making selenium-enriched yeast highly significant for human health research. Selenomethionine (SeM) is an important indicator for evaluating the quality of selenium-enriched yeast. Brewer's yeast was selected as the experimental subject, and the digestion of this yeast (Brewer's yeast) was simulated using an in vitro biomimetic gastrointestinal reactor to evaluate the effects of selenium-enriched yeast with various SeM levels on the gut flora of a healthy population. The experimental design comprised normal yeast (control group, OR), yeast containing moderate SeM levels (selenium-enriched group, SE), yeast containing high SeM levels (high-selenium group, MU), and a commercially available group comprising selenium-enriched yeast tablets (MA). The MU group exhibited a significantly higher concentration of short-chain fatty acids than the OR and MA groups during 48 h of fermentation, with significant differences observed (p < 0.05). Sequencing results revealed that the MU group showed significantly increased relative abundances of Bacteroidetes and Actinobacteria, while exhibiting a decreased ratio of Firmicutes to Bacteroidetes, which may simultaneously affect multiple metabolic pathways in vivo. These findings support the theory that selenium-enriched yeast with a high SeM has a more positive effect on human health compared with traditional yeast and offer new ideas for the development and application of selenium-enriched yeast.

Functional foods and immune system: A sustainable inhibitory approach against SARS-COV-2

Background: COVID-19 has become the center of attention since its outbreak in December 2019. Despite the discovery of its preventive vaccine, role of healthy immune system is undebatable. Functional foods are continuously hunted as a promising option for a safe natural therapeutic treatment.Purpose: This review demonstrates how functional foods can boost host immune system, promote antiviral operation, and synthesize biologically effective molecules against SARS-COV-2.Research Methodology: For current review, online search was conducted for nature-based functional immune boosters against SARS-COV-2.Conclusion: Functional foods, alongside a healthy lifestyle, fortifies the human immune system and could all help to dramatically lower the cost burden of COVID-19, the suffering of the patients, and the mortality rates worldwide.

A Family of Transglutaminases Is Essential for the Development of Appressorium-Like Structures and Phytophthora infestans Virulence in Potato

Transglutaminases (TGases) are enzymes highly conserved among prokaryotic and eukaryotic organisms, where their role is to catalyze protein cross-linking. One of the putative TGases of Phytophthora infestans has previously been shown to be localized to the cell wall. Based on sequence similarity, we were able to identify six more genes annotated as putative TGases and show that these seven genes group together in phylogenetic analysis. These seven proteins are predicted to contain both a TGase domain and a MANSC domain, the latter of which was previously shown to play a role in protein stability. Chemical inhibition of TGase activity and silencing of the entire family of the putative cell wall TGases are both lethal to P. infestans, indicating the importance of these proteins in cell wall formation and stability. The intermediate phenotype obtained with lower drug concentrations and less efficient silencing displays a number of deformations to germ tubes and appressoria. Both chemically treated and silenced lines show lower pathogenicity than the wild type in leaf infection assays. Finally, we show that appressoria of P. infestans possess the ability to build up turgor pressure and that this ability is decreased by chemical inhibition of TGases. [Formula: see text] Copyright © 2025 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.

In vitro assessment of selenium bioavailability from selenized lactic acid bacteria using a static INFOGEST digestion model and intestinal permeability model

BACKGROUND AND OBJECTIVE

Microbial selenium (Se) supplementation is an essential area of biotechnological research due to differences in the bioavailability and toxicity of different forms of selenium. To date, research has focused mainly on the use of selenized yeast. However, in recent years, scientific interest has also increased in other microorganisms, such as lactic acid bacteria (LAB), which have several unique properties that can affect the quality and bioavailability of selenium. LAB, unlike yeast, can also act as probiotics, which may bring additional health benefits related to improving the intestinal microbiota and supporting the health of the gastrointestinal tract.

METHODS

This study investigates the in vitro bioaccessibility and bioavailability of Se from two lactic acid bacterial strains, Streptococcus thermophilus CCDM 144 and Enterococcus faecium CCDM 922 A. We evaluated Se accumulation, speciation, and stability during simulated gastrointestinal digestion and Se permeation through a Caco-2 cell monolayer model.

RESULTS

Both strains accumulated Se, metabolizing it predominantly into selenium nanoparticles (SeNPs, 64-77 % of total Se), with only a minor fraction (<5 % of total Se) of organic Se species. Experiments revealed that while organic Se species had high bioavailability (up to 90 %), their bioaccessibility during digestion was very low (<0.1 % of total Se). In contrast, SeNPs showed high bioaccessibility (∼90 %) and moderate transport efficiency through the intestinal model (16-19 % after 4 hours).

CONCLUSION

These results highlight the potential of SeNPs produced by lactic acid bacteria as a bioaccessible form of Se for dietary supplementation. Further research is required to explore the behavior of SeNPs within the human body to fully understand how they can be used safely and effectively in nutrition or other applications.

Characterization of the effect of low-concentration sodium selenite on the microstructure and quality of yeast-leavened steamed bread using X-ray computed tomography

Dough fermentation is an effective method for selenium conversion. This study investigated the effects of low Na2SeO3 concentrations on the morphology, texture, fermentation properties, Se species, Se bioaccessibility, and antioxidant capacity of two types of yeast-leaved steamed bread. The results indicated that Na2SeO3 did not significantly affect the specific volume; but it did result in increased hardness. X-ray computed tomography revealed that the center of steamed bread became denser owing to Na2SeO3, and the porosity was reduced by approximately half at the highest addition level, although the cell number remained relatively unchanged. The fermentation property test demonstrated that Na2SeO3 reduced the gas production rate in dough. The conversion rate of seleno-amino acids increased with the addition of Na2SeO3, reaching a maximum of over 7 %, as did the antioxidant capacity, although the Se bioaccessibility decreased. In conclusion, this Se-enriched steamed bread reveals its potential functional benefits as a staple food.

Selenium in bread wheat (Triticum aestivum L.) grown in Buenos Aires, Argentina

BACKGROUND

Selenium (Se) is an essential micronutrient for humans, but little information is available on its nutritional status in the Argentine population.

OBJECTIVE

The aim of this study is to obtain reliable and representative data on Se content in bread wheat (Triticum aestivum L.) from the Buenos Aires province.

METHODS

The content of the micronutrient Se was determined in 242 samples of bread wheat grains (Triticum aestivum L.) from 75 districts in Buenos Aires, Argentina (representing 75 % of the wheat-producing districts in the province). Se determination was carried out by atomic absorption with hydride generation.

RESULTS

The Se content varied across the districts; in some of them, the Se levels were below the LOD (10 µg kg-1), while the highest content found was around 114 µg kg-1. The average content ( ± standard deviation) of Se in the analyzed grains was 29.90 ( ± 51.30) µg kg-1. This concentration is considered marginal or deficient according to various authors. It reflects both a low contribution of Se to diets and its low bioavailability in soils.

CONCLUSION

Further research on the Se nutritional status of the population is needed. So far, existing studies suggest a sub-optimal nutritional status, and regarding the Se content of wheat grown in Buenos Aires, it seems to be lower than the minimum recommended to maintain an adequate nutritional status through the consumption of dry plant foods. If these results are confirmed, it would be appropriate to implement strategic policies to promote the increase of Se consumption by the population. Fertilisation of wheat crops is recommended because it is a sure way to increase the Se content in the whole food chain.

The ultrastructural changes in the adult rat ovary after administration of copper oxide nanoparticles and the possible ameliorative influence of selenium

There is an important concern about the potential health and environmental risks that may develop due to exposure to copper oxide nanoparticles (CuO-NPs). Selenium is an essential trace element. It supports the expression of a variety of selenoproteins. The present study was designed to study the ultrastructural and biochemical changes in the adult rat ovary after oral administration of CuO-NPs and to assess the possible ameliorative influence of Selenium. Sixty adult female albino rats were divided in two major groups: Group I and Group II. Group I was further subdivided into three groups: Group IA (control), Group IB: received a single high dose of 2000 mg/kg CuO-NPs, Group IC: received selenium (0.5 mg/kg), five days before giving a single high dose of CuO-NPs (2000 mg/kg). Thereafter, given selenium for 14 days. Group II was subdivided into three groups: Group IIA (control), Group IIB: received a small dose of 300 mg/kg of CuO-NPs for 28 days, Group IIC: received selenium (0.5 mg/kg), five days before starting concomitant administration of CuO-NPs (300 mg/kg) and Selenium (0.5 mg/kg) for 28 days. Damage of the ovarian ultrastructural features, increased MDA levels, and decreased serum estrogen and progesterone hormones levels were detected in group IB and group IIB. Group IC and group IIC showed improvement of ovarian ultrastructural, decreased MDA levels, and increased serum estrogen and progesterone hormones levels as compared to group IB and group IIB indicating that Selenium could decrease the damage induced by CuO-NPs in the adult rat ovaries.

The Promising Role of Selenium and Yeast in the Fight Against Protein Amyloidosis

In recent years, increasing attention has been paid to research on diseases related to the deposition of misfolded proteins (amyloids) in various organs. Moreover, modern scientists emphasise the importance of selenium as a bioelement necessary for the proper functioning of living organisms. The inorganic form of selenium-sodium selenite (redox-active)-can prevent the formation of an insoluble polymer in proteins. It is very important to undertake tasks aimed at understanding the mechanisms of action of this element in inhibiting the formation of various types of amyloid. Furthermore, yeast cells play an important role in this matter as a eukaryotic model organism, which is intensively used in molecular research on protein amyloidosis. Due to the lack of appropriate treatment in the general population, the problem of amyloidosis remains unsolved. This extracellular accumulation of amyloid is one of the main factors responsible for the occurrence of Alzheimer's disease. The review presented here contains scientific information discussing a brief description of the possibility of amyloid formation in cells and the use of selenium as a factor preventing the formation of these protein aggregates. Recent studies have shown that the yeast model can be successfully used as a eukaryotic organism in biotechnological research aimed at understanding the essence of the entire amyloidosis process. Understanding the mechanisms that regulate the reaction of yeast to selenium and the phenomenon of amyloidosis is important in the aetiology and pathogenesis of various disease states. Therefore, it is imperative to conduct further research and analysis aimed at explaining and confirming the role of selenium in the processes of protein misfolding disorders. The rest of the article discusses the characteristics of food protein amyloidosis and their use in the food industry. During such tests, their toxicity is checked because not all food proteins can produce amyloid that is toxic to cells. It should also be noted that a moderate diet is beneficial for the corresponding disease relief caused by amyloidosis.

The Frequently Used Industrial Food Process Additive, Microbial Transglutaminase: Boon or Bane

Microbial transglutaminase (mTG) is a frequently consumed processed food additive, and use of its cross-linked complexes is expanding rapidly. It was designated as a processing aid and was granted the generally recognized as safe (GRAS) classification decades ago, thus avoiding thorough assessment according to current criteria of toxicity and public health safety. In contrast to the manufacturer's declarations and claims, mTG and/or its transamidated complexes are proinflammatory, immunogenic, allergenic, pathogenic, and potentially toxic, hence raising concerns for public health. Being a member of the transglutaminase family and functionally imitating the tissue transglutaminase, mTG was recently identified as a potential inducer of celiac disease. Microbial transglutaminase and its docked complexes have numerous detrimental effects. Those harmful aspects are denied by the manufacturers, who claim the enzyme is deactivated when heated or by gastric acidity, and that its covalently linked isopeptide bonds are safe. The present narrative review describes the potential side effects of mTG, highlighting its thermostability and activity over a broad pH range, thus, challenging the manufacturers' and distributers' safety claims. The national food regulatory authorities and the scientific community are urged to reevaluate mTG's GRAS status, prioritizing public health protection against the possible risks associated with this enzyme and its health-damaging consequences.

Progressive structural changes of microbial transglutaminase modified fish gelatin during gastric digestion

This study investigated the progressive structural changes of fish gelatin in thermally reversible (TR) and irreversible (TI) states, formed through microbial transglutaminase (MTGase) cross-linking during in vitro gastric digestion. The focus was on dynamic structural changes and gastric digestion characteristics. Free amino content and SDS-PAGE analyses showed that both TR and TI groups were hydrolyzed into smaller fragments by pepsin during digestion. Surface hydrophobicity and endogenous fluorescence analyses revealed that hydrophobic groups in TR samples became embedded, whereas those in TI samples were exposed as digestion progressed. The microstructure of fish gelatin varied states and changed over digestion time. Two digestion patterns were observed: the fitted curves of TR groups exhibited initially increasing that later stabilized, whereas the TI samples followed an S-shaped curve with three distinct stages-an initial stable phase, followed by a rise, and concluding with a final stabilization. A schematic model illustrated the dynamic structural changes of fish gelatin in different states during simulated gastric digestion. This study provides a basis for the development of high-quality collagen supplement products.

Composition, Influencing Factors, and Effects on Host Nutrient Metabolism of Fungi in Gastrointestinal Tract of Monogastric Animals

Intestinal fungi, collectively referred to as mycobiota, constitute a small (0.01-2%) but crucial component of the overall intestinal microbiota. While fungi are far less abundant than bacteria in the gut, the volume of an average fungal cell is roughly 100-fold greater than that of an average bacterial cell. They play a vital role in nutrient metabolism and maintaining intestinal health. The composition and spatial organization of mycobiota vary across different animal species and are influenced by a multitude of factors, including age, diet, and the host's physiological state. At present, quantitative research on the composition of mycobiota in monogastric animals remains scarce, and investigations into the mechanisms underlying their metabolic functions are also relatively restricted. This review delves into the distribution characteristics of mycobiota, including Candida albicans, Saccharomyces cerevisiae, Kazachstania slooffiae, in monogastric animals, the factors influencing their composition, and the consequent impacts on host metabolism and health. The objective is to offer insights for a deeper understanding of the nutritional significance of intestinal fungi in monogastric animals and to explore the mechanisms by which they affect host health in relation to inflammatory bowel disease (IBD), diarrhea, and obesity. Through a systematic evaluation of their functional contributions, this review shifts our perception of intestinal fungi from overlooked commensals to key components in gut ecosystem dynamics, emphasizing their potential in personalized metabolic control regulation and the enhancement of disease prevention and treatment strategies.

Genome Sequencing, Assembly, and Characterization of Cyberlindnera rhodanensis J52 as a Non-Saccharomyces Yeast with Ester-Enhancing Potential

Cyberlindnera rhodanensis J52, a non-Saccharomyces yeast isolated from edible roses, markedly improves the organoleptic qualities of fermented foods. To facilitate the development and application of this strain, this study sequenced and assembled the genome of C. rhodanensis J52, subsequently conducting functional annotation of its genes utilizing the NR, Swiss-Prot, COG, GO, KEGG and CAZy databases. The findings revealed that this yeast harbors genes involved in the biosynthesis of flavor compounds, including higher alcohols, acetate esters, ethyl esters, volatile organic acids, aromatic amino acids and benzyl alcohol or benzaldehyde. Furthermore, it possesses β-glucosidase, an extracellular enzyme which enhances the flavor profile of fermented products. Further analysis revealed that the yeast features biosynthetic pathways for the production of isoamyl acetate, isoamyl 2-methylbutyrate, benzyl acetate, phenethyl acetate, ethyl butanoate and ethyl decanoate, which verifies its ability to produce esters at the genetic level. Additionally, the yeast was found to have the capacity to biosynthesize selenoproteins, suggesting that it not only enhances flavor but also imparts functional benefits. These findings provide a theoretical foundation for the further exploration and application of C. rhodanensis J52.

Microbial Transglutaminase-The Food Additive, a Potential Inducing Factor in Primary Biliary Cholangitis

Microbial transglutaminase (mTG) is a bacterial survival factor, which is frequently used as a food additive. This results in the formation of immunogenic epitopes that may cause autoimmunity. Primary biliary cholangitis (PBC) is a cholestatic, autoimmune liver disease characterized by the presence of characteristic autoantibodies. The aim of this work was to determine epitope similarity and cross-reactivity between mTG- and PBC-specific antigens and to investigate whether the microbial enzyme may be associated with the induction of autoimmunity due to epitope similarity and cross-reactivity. Monoclonal and polyclonal antibodies against mTG were applied to nine different PBC-specific antigens using ELISA technique. They reacted significantly with four out of nine antigens. This reaction was most pronounced for gp210 and PML protein. We also performed in vitro studies on the impact of the mTG on the specific antigen-antibody binding using sera of PBC patients. We found four PBC-specific antigens that share homology with mTG sequences. We noticed inhibition of this specific binding by the mTG to the PDC M2, gp210, PML, and KLHL12 protein. Microbial mimics may be the major targets of cross-reactivity with human-specific antigens. Cross-reactivity may indicate a link between mTG and the development of autoimmune diseases.

Multi-omics investigation of high-transglutaminase production mechanisms in Streptomyces mobaraensis and co-culture-enhanced fermentation strategies

Transglutaminase (TGase) has been widely applied in the food industry. However, achieving high-yield TGase production remains a challenge, limiting its broader industrial application. In this study, a high-yield strain with stable genetic traits was obtained through UV-ARTP combined mutagenesis, achieving a maximum TGase activity of 13.77 U/mL, representing a 92.43% increase. Using this strain as a forward mutation gene pool, comparative genomic research identified 95 mutated genes, which were mostly due to base substitutions that led to changes in codon usage preference. Transcriptomic analysis revealed significant expression changes in 470 genes, with 232 upregulated and 238 downregulated genes. By investigating potential key regulatory factors, comprehensive analysis indicated that changes in codon usage preference, amino acid metabolism, carbon metabolism, protein export processes, TGase activation, and spore production pathways collectively contributed to the enhancement of TGase activity. Subsequently, the in vitro activation efficiency of TGase was further improved using co-cultivation techniques with neutral proteases secreted by Bacillus amyloliquefaciens CICC10888, and a TGase activity of 16.91 U/mL was achieved, accounting for a 22.71% increase. This study provides a comprehensive understanding of the mechanisms underlying high-yield TGase production and valuable insights and data references for future research.

Selenium Mitigates Caerulein and LPS-induced Severe Acute Pancreatitis by Inhibiting MAPK, NF-κB, and STAT3 Signaling via the Nrf2/HO-1 Pathway

Severe acute pancreatitis (SAP) leads to systemic inflammation, resulting in multiorgan damage. Acute lung injury and acute respiratory distress syndrome develop in one-third of SAP patients, with a high mortality rate of 60% due to secondary complications. Patients with pancreatitis often have selenium deficiency, and selenium supplements may provide beneficial effects. This study examined the protective role of selenium in a model of SAP induced by caerulein + lipopolysaccharide (cae + LPS). Mice were administered selenium (1 mg/kg) before being challenged with caerulein (6 injections of 50 μg/kg) and LPS (10 mg/kg). At 3 h after the last caerulein injection, blood was collected for estimating pancreatic enzymes and cytokine levels, and the mice were euthanized. We performed morphological and histological studies, measured levels of protease and oxidative stress markers and conducted western blot, ELISA, and RT-qPCR analyses. We examined lung tissue histologically and estimated myeloperoxidase levels. Selenium pretreatment significantly reduced pancreatic enzyme levels such as amylase, lipase, and proteases (specifically MMPs) and reversed tissue injury in the pancreas and lungs caused by cae + LPS. In addition, selenium-treated mice showed decreased levels of inflammatory markers and chemokines. Examination of the downstream inflammatory pathways confirmed the protective effect of selenium, which mediates its anti-inflammatory and antioxidant action by inhibiting the major inflammatory signaling pathways (MAPKs, NF-κB, and STAT3) and activating the phosphorylation of Nrf2 via Nrf2/HO-1 pathways. These findings suggest that selenium may be a potential therapeutic option for treating SAP-associated secondary complications.

Associations between serum selenium and serum lipids in adolescents aged 12-19: A cross-sectional study

BACKGROUND

Selenium is an essential trace element in the human body and is important in lipid metabolism. Previous studies on the relationship between selenium and serum lipids were almost conducted in adults, and the research conclusions were inconsistent. Evidence linking selenium and lipids in adolescents is very limited. As an important stage of growth and development, studying the effects of trace elements on the body during adolescence is meaningful.

OBJECTIVE

This study examined the association between serum selenium and serum lipids in adolescents aged 12-19.

METHODS

This cross-sectional study analyzed 2209 adolescents aged 12-19 years from NHANES 2011 to 2016. Multiple linear regression analyses were performed to evaluate selenium's association with serum lipids (containing TC, TG, LDL-C, and HDL-C). Moreover, a generalized additive model (GAM) and a fitted smoothing curve (penalized spline method) were conducted to explore the exact curve shape between them.

RESULTS

In the fully adjusted model, it showed a positive association between selenium and TC, TG, LDL-C [TC (β = 0.144 (, 95 % CI (0.084, 0.204), P < 0.001), TG (β = 0.285, 95 % CI (0.134, 0.437), P < 0.001), LDL-C (β = 0.098, 95 % CI (0.022, 0.174), P = 0.011)], whereas a negative association [(β = -0.031, 95 % CI (-0.054, - 0.009), P = 0.006)] between Se and HDL-C. Subgroup analysis showed that the above associations were more significant in females aged 12-19 (P for trend < 0.05). Furthermore, linear associations were performed in Se between TC and LDL-C.

CONCLUSION

This is the first study to find evidence demonstrating associations between serum Se and serum lipids in adolescents aged 12-19. The validation of our findings will require further research.

Optimization of fermentation conditions for microbial transglutaminase production by Streptoverticillium cinnamoneum KKP 1658 using response surface methodology (RSM)

Microbial transglutaminase (MTG) is an enzyme widely used in the food industry because it creates cross-links between proteins, enhancing the texture and stability of food products. Its unique properties make it a valuable tool for modifying the functional characteristics of proteins, significantly impacting the quality and innovation of food products. In this study, response surface methodology was employed to optimize the fermentation conditions for microbial transglutaminase production by the strain Streptoverticillium cinnamoneum KKP 1658. The effects of nitrogen dose, cultivation time, and initial pH on the activity of the produced transglutaminase were investigated. The significance of the examined factors was determined as follows: cultivation time > nitrogen dose > pH. The interaction between nitrogen dose and cultivation time was found to be crucial, having the second most significant impact on transglutaminase activity. Optimal conditions were identified as 48 h of cultivation with a 2% nitrogen source dose and an initial medium pH of approximately 6.0. Under these conditions, transglutaminase activity ranged from 4.5 to 5.5 U/mL. The results of this study demonstrated that response surface methodology is a promising approach for optimizing microbial transglutaminase production. Future applications of transglutaminase include the development of modern food products with improved texture and nutritional value, as well as its potential use in regenerative medicine for creating biomaterials and tissue scaffolds. This topic is particularly important and timely as it addresses the growing demand for innovative and sustainable solutions in the food and biomedical industries, contributing to an improved quality of life.

Exploring the impact of selenium-enriched peptides from yeast autolysate on dough properties: Insights into mechanisms from gluten perspectives

This study investigated the impact of Selenium (Se)-enriched yeast autolytic peptides (SeYAP) with different Se levels on dough properties as well as the related mechanism by focusing on gluten. SeYAP prolonged the dough's development time by up to 131 % and stability time by up to 28 %. It also decreased dough's viscoelasticity and rendered dough softer. Additionally, SeYAP diminished the binding capacity of dough to water and augmented the fluidity of water. Protein composition, disulfide bonds and fluorescence spectroscopy revealed that SeYAP could induce depolymerization of glutenin aggregate through sulfhydryl/disulfide bond exchange and hydrophobic interactions. Seven Se-enriched peptides were identified from the fraction with strong ability to depolymerize gluten. Specifically, six peptides contained selenocysteine, while another peptide contained selenomethionine. Molecular docking indicated that Se-enriched peptides could interact with amino acids (such as glutamine, tyrosine and proline) in gluten via hydrophobic interactions and/or hydrogen bonds.

Products of Selenite/Thiols Interaction Have Reducing Properties, Cleave Plasmid DNA and Decrease Rat Blood Pressure and Tension of Rat Mesenteric Artery

Selenium compounds exert their antioxidant activity mostly when the selenium atom is incorporated into selenoproteins. In our work, we tested the possibility that selenite itself interacts with thiols to form active species that have reducing properties. Therefore, we studied the reduction of 2-(4-carboxyphenyl)-4,5-dihydro-4,4,5,5-tetramethyl-1H-imidazol-1-yloxy-3-oxide radical (•cPTIO), damage of plasmid DNA (pDNA), modulation of rat hemodynamic parameters and tension of isolated arteries induced by products of interaction of selenite with thiols. We found that the products of selenite interaction with thiols had significant reducing properties that could be attributed mainly to the selenide and that selenite had catalytic properties in the access of thiols. The potency of thiols to reduce •cPTIO in the interaction with selenite was cysteine > homocysteine > glutathione reduced > N-acetylcysteine. Thiol/selenite products cleaved pDNA, with superoxide dismutase enhancing these effects suggesting a positive involvement of superoxide anion in the process. The observed •cPTIO reduction and pDNA cleavage were significantly lower when selenomethionine was used instead of selenite. The products of glutathione/selenite interaction affected several hemodynamic parameters including rat blood pressure decrease. Notably, the products relaxed isolated mesenteric artery, which may explain the observed decrease in rat blood pressure. In conclusion, we found that the thiol/selenite interaction products exhibited significant reducing properties which can be used in further studies of the treatment of pathological conditions caused by oxidative stress. The results of decreased rat blood pressure and the tension of mesenteric artery may be perspective in studies focused on cardiovascular disease and their prevention.

Review of the potential for selenium remobilization in semi-passive treatment systems of mine impacted waters

Biological semi-passive mine water treatment technologies are used in the mining industry as an alternative to or in conjunction with active treatment systems to remediate mine impacted water (MIW) containing nitrate and selenium oxyanions such as selenate and selenite. In semi-passive biological treatment systems, MIW is pumped through a saturated, porous media (either a gravel bed or waste rock) which provides ample surface area for biofilm growth and the creation of anoxic, subaqueous environments. Additional nutrients and carbon sources are pumped into the system to encourage the growth of microbes that biochemically reduce selenate and selenite to insoluble reduced Se0 species such as selenium nanoparticles (SeNP) by respiring selenate and selenite. One such semi-passive treatment process, the saturated rock fill (SRF), injects MIW into backfilled open pits. Currently, it is contemplated that the SRF technology will treat over 170,000 m3/day of MIW in Southwest British Columbia in Canada and operate for decades if not longer. Following closure, the SRFs will retain significant quantities of selenium removed from water in perpetuity. Despite advancements in physical design and understanding operational performance of SRFs, there has been little publicly available information on the long-term fate and stability of the reduced Se0 retained in the system following closure (i.e., 100 or more years into the future). Here, we review available and relevant scientific literature to highlight the significance of this knowledge gap. Based on an extensive literature review and analyses using known, published chemical reactions, we discuss conditions in which immobilized Se0 formed from selenate and selenite bioreduction in the SRFs can remobilize and propose actionable steps to better understand the future environmental implications of implementing the SRFs.

Effects of Sodium Selenate on Growth, Selenium Forms, and Nutritional Quality of Chlorella pyrenoidosa

In this study, C. pyrenoidosa were cultured with seven different concentrations of Na2SeO4 (0-10 mg/L), and the effects of Na2SeO4 on the growth, Se-forms, and nutritional quality of C. pyrenoidosa were explored. The results showed that at the concentration of 0.5 mg/L Na2SeO4, the C. pyrenoidosa were plump and healthy; the contents of biomass, soluble protein, lipids, and TPUFA reached the highest level; the total Se content in C. pyrenoidosa increased with the increasing Na2SeO4 concentrations. However, the proportion of organic Se in C. pyrenoidosa. reached the highest value of 87.58% at the concentration of 0.5 mg/L Na2SeO4. Among organic Se forms, SeMet accounted for the largest proportion, while MeSeCys accounted for a relatively smaller proportion, but SeCys2 was not detected. The addition of Na2SeO4 (except for ≤0.5 mg/L) reduced the contents of photosynthetic pigments in C. pyrenoidosa. In addition, the antioxidant capacity of C. pyrenoidosa first increased and then decreased with the increasing Na2SeO4 concentrations, but different enzymes exhibited different tolerances to Na2SeO4. Based on the above research results, 0.5 mg/L Na2SeO4 concentration is recommended for the production of Se-rich C. pyrenoidosa. Our findings will provide a theoretical basis and practical references for the development of Se-rich C. pyrenoidosa health care products.

Clinical and mechanistic insights into biomedical application of Se-enriched probiotics and biogenic selenium nanoparticles

Selenium is an essential element with various industrial and medical applications, hence the current considerable attention towards the genesis and utilization of SeNPs. SeNPs and other nanoparticles could be achieved via physical and chemical methods, but these methods would not only require expensive equipment and specific reagents but are also not always environment friendly. Biogenesis of SeNPs could therefore be considered as a less troublesome alternative, which opens an excellent window to the selenium and nanoparticles' world. bSeNPs have proved to exert higher bioavailability, lower toxicity, and broader utility as compared to their non-bio counterparts. Many researchers have reported promising features of bSeNP such as anti-oxidant and anti-inflammatory, in vitro and in vivo. Considering this, bSeNPs have been tried as effective agents for health disorders, especially as constituents of probiotics. This article briefly reviews selenium, selenium nanoparticles, Se-enriched probiotics, and bSeNPs' usage in an array of health disorders. Obviously, there are very many articles on bSeNPs, but we wanted to summarize studies on prominent bSeNPs features published in the twenty-first century. This review is hoped to give an outlook to researchers for their future investigations, ultimately serving better care of health disorders.

The Impact of Selenium on the Physiological Activity of Yeast Cells Saccharomyces cerevisiae ATCC 7090 and Rhodotorula glutinis CCY 20-2-26

BACKGROUND

This study investigated the selenium-binding capacity of the biomass of two yeast strains, Saccharomyces cerevisiae American Type Culture Collection (ATCC) 7090 and Rhodotorula glutinis CCY 20-2-26.

METHODS

The studies carried out methods of bioaccumulation by yeast biomass. Inorganic selenium was added to the culture media as an aqueous solution of Na2SeO3 at concentrations ranging from 0 to 40 mg Se4+/L.

RESULTS

The addition of selenium at concentrations >0.5 mg/L significantly reduced biomass yield compared with the control in the case of S. cerevisiae. A significant reduction in the biomass of R. glutinis was observed only at selenium doses >30 mg/L. The study found that for S. cerevisiae, cultivation should occur for 24 h in a medium with an initial selenium concentration of 20 mg/L to achieve the most efficient selenium accumulation by the yeast biomass. Under these conditions, the yeast could accumulate 4.27 mg Se4+/g. For the red yeast R. glutinis, optimal selenium binding conditions were achieved by cultivating for 48 h in a medium with an initial selenium ion concentration of 40 mg/L. This yeast strain was more resistant to high selenium doses, accumulating 7.53 mg Se4+/L at the highest tested dose (40 mg Se4+/L). Selenium supplementation of the medium from 20 mg Se4+/L and cultivation for 72 h caused significant changes in the morphology of S. cerevisiae cells (e.g., increased surface area compared with the control). Selenium doses of 20-40 mg/L after 48 h of cultivation significantly reduced the surface area compared with the control results for R. glutinis cells.

CONCLUSIONS

Selenium significantly impacted carotenoid pigment production, with levels decreasing as the selenium concentration in the medium increased. Furthermore, selenium in the tested concentration range increased protein content in the cellular biomass but did not affect intracellular lipid production.

The mediating role of inflammatory biomarkers in the association between serum copper and sarcopenia

This study aims to investigate the association between serum copper (Cu), selenium (Se), zinc (Zn), Se/Cu and Zn/Cu ratios and the risk of sarcopenia. In this study, which involved 2766 adults aged ≥ 20 years enrolled in the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2016, multivariable logistic regression, restricted cubic spline (RCS) models and mediation analyses were used. After full adjustment, multivariable logistic regression revealed that higher serum copper levels were correlated with an increased risk of sarcopenia. Conversely, higher serum Se/Cu (OR 0.45, 95% CI 0.23-0.89, P = 0.023) and Zn/Cu (OR 0.49, 95% CI 0.27-0.90, P = 0.024) were associated with a decreased risk of sarcopenia. The RCS curve indicated a non-linear, roughly inverted L-shaped relationship between serum Cu and sarcopenia risk (P non-linear < 0.001). Additionally, Se/Cu (P non-linear = 0.179) and Zn/Cu (P non-linear = 0.786) showed negative linear associations with sarcopenia risk. Furthermore, white blood cell (WBC) count, neutrophil count, and systemic inflammation index (SII) were identified as significant mediators in the relationship between serum Cu and the risk of sarcopenia, with mediation proportions of 6.34%, 6.20%, and 4.37%, respectively (all P < 0.05). Therefore, balancing essential trace metals is crucial for maintaining muscle health.

Exploring the potential association between serum selenium and hypertension in obese adult males in the United States

Previous studies on the correlation between serum selenium and hypertension have yielded inconsistent results. Our previous analysis of participants from the National Health and Nutrition Examination Survey (NHANES) 2011-2018 indicated that elevated serum selenium concentrations were associated with an increased risk of metabolic abnormalities in obese individuals, with the primary effect being on blood pressure in males. The aim of this study was to further elucidate the relationship between serum selenium and the risk of hypertension in obese males. In this study, we examined the correlation between serum selenium concentrations and hypertension in 2,585 male participants with a body mass index (BMI) ≥ 30 kg/m2 aged between 20 and 80 years from the 2011-2018 NHANES database. The associations between serum selenium levels and hypertension were evaluated through weighted generalized linear regression analyses. To examine the saturation threshold effect between serum selenium and hypertension, a generalized additive model (GAM) and a two-piecewise linear regression model were employed. Furthermore, the saturation threshold effect was evaluated separately in subgroups stratified by BMI and age. The weighted prevalence of hypertension (51.84%) was slightly higher than that of nonhypertension (48.16%) in the participants included in this study. After rigorous adjustment for sociodemographic, physical, and laboratory test covariates, the weighted odds ratio (OR) of hypertension increased by 103% for every 1 standard deviation (SD) increase (approximately 24.41 µg) in the serum selenium concentration in participants assigned to the highest serum selenium group (weighted OR = 2.03; 95% CI = 1.24-3.32; P = 0.013). A calculation was subsequently performed to determine the saturation threshold effect of selenium on hypertension among participants in the medium and highest selenium concentration subgroups. The findings indicated that participants with serum selenium concentrations exceeding the saturation threshold (2.56 µM) demonstrated an elevated risk of developing hypertension (weighted OR = 9.58; 95% CI = 2.74-33.46; P = 0.000) in comparison to those with serum selenium concentrations below the threshold. Subgroup analyses demonstrated that serum selenium concentrations exceeding the saturation threshold were associated with an increased risk of hypertension in participants with a BMI ≤ 35 kg/m2 (weighted OR = 9.11; 95% CI = 1.43-58.24; P = 0.030) or those aged less than 55 years or younger (weighted OR = 8.37; 95% CI = 1.71-40.94; P = 0.014). For obese adult males who require additional selenium supplementation to enhancing their overall health and well-being, it is strongly recommended that the serum selenium concentrations be monitored throughout the course of supplementation to ensure that they remain within the relatively safe range (approximately less than 215.75 µg/L).

The influence of sampling method and season on modeling of selenium into coldwater fish and implications on tissue-based water quality benchmarks

Selenium (Se) contamination of aquatic ecosystems has led to the local extirpation of some Se-sensitive fish species. Although Se exposure occurs primarily via diet, considerable uncertainty lies in modeling Se transfer and bioaccumulation from sediment, detritus, and/or periphyton through benthic macroinvertebrates (BMI) to fish. Here we estimated Se concentrations in four coldwater fish species (northern pike, white sucker, lake whitefish, and ninespine stickleback) inhabiting boreal lakes downstream from a uranium mill in northern Canada. In addition, we evaluated the potential effects of BMI and periphyton sampling methods (artificial substrates vs. grab samples), seasons (summer vs. winter), and models (USEPA vs. Assessment of the Dispersion and Effects of Parameter Transport) on the estimated Se concentrations in fish tissue. Results were compared with site-specific benchmarks and observed Se concentrations in resident fish. In summer 2019, periphyton and BMI were sampled at 10 sampling stations (two in Vulture Lake and eight in McClean Lake) using artificial substrates (n = 4) and sediment grab samples (n = 3). In winter 2021, samples were collected in McClean Lake (n = 3) through ice holes using a sediment grab sampler. Estimated Se concentrations in fish tissue depended on the surface sediment or periphyton Se concentrations used in the models. At Vulture Lake, Se concentrations in northern pike muscle estimated using the grab sample data (17.3 ± 11.5 µg/g DW), but not the artificial substrates (34.5 ± 1.2 µg/g DW), were comparable with the observed mean concentration (19.0 ± 1.4 µg/g DW) in this species. At McClean Lake, Se body burdens in forage fish estimated using data from both sampling methods were comparable with measured data. Significantly lower mean whole-body Se concentrations were estimated for all fish species in winter (1.0 ± 0.3 µg/g DW) relative to summer (4.8 ± 1.6 µg/g DW). Further investigation is necessary to understand how potential seasonal shifts in dietary Se exposure relate to fish reproduction and early life stages.

Dietary Se-enrich Cardamine violifolia supplementation decreases lipid deposition and improves antioxidant status in the liver of aging laying hens

Aging-related lipid metabolic disorder is related to oxidative stress. Selenium (Se)-enriched Cardamine violifolia (SEC) is known for its excellent antioxidant function. The objective of this study was to evaluate the effects of SEC on antioxidant capacity and lipid metabolism in the liver of aged laying hens. A total of 450 sixty-five-wk-old Roman laying hens were randomly divided into 5 treatments: a basal diet (without Se supplementation, CON) and basal diets supplemented with 0.3 mg/kg Se from sodium selenite (SS), 0.3 mg/kg Se from Se-enriched yeast (SEY), 0.3 mg/kg Se from SEC (SEC), or 0.3 mg/kg Se from SEC and 0.3 mg/kg Se from SEY (SEC + SEY). The experiment lasted for 8 wk. The results showed that dietary SEC + SEY supplementation decreased (P < 0.05) triglyceride (in the plasma and liver) and total cholesterol levels (in the plasma), and increased (P < 0.05) HDL-C concentration in plasma compared to CON diet. Compared with CON diet, SEC and/or SEY supplementation decreased (P < 0.05) the mRNA expression of hepatic ACC, FAS and HMGCR, and increased (P < 0.05) PPARα, VTG-II, Apo-VLDL II and ApoB expression. Dietary SEC + SEY and SEY supplementation increased (P < 0.05) Se content in egg yolk and breast muscle compared to CON diet. Dietary SEC, SEY or SEC + SEY supplementation increased (P < 0.05) the activity of antioxidant enzymes (GSH-PX, T-AOC and T-SOD) in the plasma and liver and decreased (P < 0.05) MDA content in the plasma compared to CON diet. Dietary Se supplementation promoted (P < 0.05) mRNA expression of Nrf2 in the liver. In contrast, dietary SEY and SEC supplementation resulted in a decrease (P < 0.05) of hepatic Keap1 mRNA expression compared to CON diet. Dietary SEC + SEY and/or SEC supplementation increased (P < 0.05) mRNA expression of Selenof, GPX1 and GPX4 in the liver compared with CON diet. In conclusion, dietary SEC (0.3 mg/kg Se) or SEC (0.3 mg/kg Se) + SEY (0.3 mg/kg Se) improved the antioxidant capacity and the lipid metabolism in the liver of aged laying hens, which might be associated with regulating Nrf2/Keap1 signaling pathway.

Effects of exogenous selenium application on quality characteristics, selenium speciation, and in vitro bioaccessibility of rice pancakes

Selenium is an essential trace element for human health. To date, a hotspot of functional foods is strengthening the content of organic Se in food using biological Se enrichment. Herein, Se-enriched rice pancakes were produced by directly adding different sodium selenite concentrations into the fermentation process. The effects of sodium selenite addition on the texture properties, structure, and Se species of rice pancakes were investigated. Meanwhile, the bioaccessibility of Se and the changes of Se species in Se-enriched rice pancakes were determined by digestion experiments in vitro. The results showed significant differences in hardness, adhesiveness, chewiness, porosity, and flavor substances of Se-enriched rice pancakes after adding sodium selenite (p < 0.05). In Se-enriched rice pancakes, selenocystine (SeCys2) and methylselenocysteine (MeSeCys) are the main Se species. When sodium selenite was added at 3.3 μg/mL, the maximum values of SeCys2 and MeSeCys were 328.35 ± 33.43 and 311.11 ± 49.48 μg/kg, respectively. Se bioaccessibility was negatively correlated with sodium selenite content. The electronic nose results of Se-enriched rice pancakes showed that the sulfur compounds, nitrogen substances, alcohol substances, alkane substances, alcohols, aldehydes, and ketones in rice pancakes significantly increased following sodium selenite addition. The results can provide a significant basis for developing high efficiency Se-enriched fermented food and the processing of Se-enriched rice pancakes.

Empowering canonical biochemicals with cross-linked novelty: Recursions in applications of protein cross-links

Diversity in the biochemical workhorses of the cell-that is, proteins-is achieved by the innumerable permutations offered primarily by the 20 canonical L-amino acids prevalent in all biological systems. Yet, proteins are known to additionally undergo unusual modifications for specialized functions. Of the various post-translational modifications known to occur in proteins, the recently identified non-disulfide cross-links are unique, residue-specific covalent modifications that confer additional structural stability and unique functional characteristics to these biomolecules. We review an exclusive class of amino acid cross-links encompassing aromatic and sulfur-containing side chains, which not only confer superior biochemical characteristics to the protein but also possess additional spectroscopic features that can be exploited as novel chromophores. Studies of their in vivo reaction mechanism have facilitated their specialized in vitro applications in hydrogels and protein anchoring in monolayer chips. Furthering the discovery of unique canonical cross-links through new chemical, structural, and bioinformatics tools will catalyze the development of protein-specific hyperstable nanostructures, superfoods, and biotherapeutics.

A Method for Fabricating Tissue-Specific Extracellular Matrix Blocks From Decellularized Tissue Powders

Decellularized tissues retain the extracellular matrix (ECM), shape, and composition that are unique to the source tissue. Previous studies using decellularized tissue lysates and powders have shown that tissue-specific ECM plays a key role in cellular function and wound healing. However, creating decellularized tissues composed of tissue-specific ECM with customizable shapes and structures for use as scaffolding materials remains challenging. In this study, a method for compacting decellularized tissue powder into blocks is developed using cold isostatic pressing (CIP). Custom-shaped ECM blocks and composite ECM blocks are fabricated using silicone molds. Additionally, an ECM block with a two-layer structure is obtained through a two-step CIP process. Cells are observed to infiltrate porous ECM blocks that are created using sodium chloride and transglutaminase. These results highlight the development of an effective method for producing ECM blocks using CIP with customizable shapes, compositions, and structures, making them suitable for use as cell culture scaffolds.

Systematic characterization of selenium speciation in coal fly ash

Millions of tons of coal fly ashes (CFAs) are produced annually during coal combustion in the U.S., which are commonly beneficially used in the concrete industry or disposed of in ash ponds. CFAs contain trace amounts of a range of toxic heavy metals including selenium (Se). Because the toxicity of Se is dependent on its speciation, investigating Se speciation in CFAs as affected by coal source and combustion conditions can help understand the related environmental and human health impacts during disposal or beneficial reuse. In this study, a set of representative CFA samples were characterized for Se speciation using synchrotron X-ray absorption spectroscopy (XAS) and micro-X-ray fluorescence spectromicroscopy (μ-XRF/XAS). Se-containing particles were highly heterogeneous, and individual particles might contain multiple oxidation states including Se(0), Se(IV), and Se(VI). Principal component analysis was performed for sample characteristics including Al2O3, SiO2, CaO, FeO, loss on ignition, average particle size, Se concentration, and Se oxidation state. Selective catalytic reduction (SCR), which is used to limit nitrogen oxide (NOx) emissions during coal combustion, was found to be associated with the presence of reduced Se oxidation states, with up to 90% Se(0) observed in samples with SCR. Alongside SCR, FeO content may also influence Se speciation.

Selenium mitigated cadmium-induced ovarian retardation in female Procambarus clarkii by regulating vitellogenin synthesis and transfer in the hepatopancreas

Cadmium (Cd) is prevalent in aquatic ecosystems and accumulates in various tissues of aquatic organisms, leading to severe biological toxicity. Selenium (Se) is recognized for mitigating heavy metal toxicity, though its protective effects against Cd in aquatic crustaceans remain underexplored. This study, therefore, assessed the effects of dietary Cd (15 mg/kg) exposure and Se (6 mg/kg) supplementation on the hepatopancreas and ovaries of female crayfish to uncover the mechanisms of Cd toxicity and the protective role of Se. The results showed that Cd accumulation in the hepatopancreas caused a reduced hepatopancreas index (HPI), decreased protein content, histopathological damage, and oxidative stress, while Se supplementation reduced Cd levels, mitigated damage, and restored tissue integrity and antioxidant defenses. Transcriptomic analysis further revealed significant alterations in gene expression related to detoxification, lipid metabolism, and energy production in response to Cd exposure, which were partially or fully restored by Se supplementation. Additionally, Se alleviated Cd-induced inhibition of ovarian development, as evidenced by improved ovary index, enhanced oocyte development, and normalization of essential trace element levels. Mechanistically, Se restored the Cd-disrupted vitellogenin (Vtg) synthesis in the hepatopancreas via regulating the mRNA expression of hsp70 and genes related to the molt-inhibiting hormone (MIH) (mih, rxr, and ecr). Overall, these findings indicate that Se supplementation mitigated Cd-induced hepatopancreatic dysfunction, restored Vtg synthesis, and consequently counteracted the inhibition of ovarian development in adult female crayfish.

Characterization and subcellular localization of selenium in Limosilactobacillus fermentum Ln-9 obtained by intense pulsed light-ultraviolet combined mutagenesis

Lactic acid bacteria (LAB) can convert inorganic selenium (Se) to organic Se and elemental forms with low toxicity and high bioavailability, but a comprehensive Se analysis of Se-enriched LAB is lacking. In this study, Limosilactobacillus fermentum Ln-9 was obtained by intense pulsed light-ultraviolet combined mutagenesis, and its characteristics and subcellular localization of Se were analyzed. The results displayed that Ln-9 accumulated 3.03 times Se that of the original strain. Under optimal fermentation conditions, the total Se content of Se-enriched Ln-9 (SeLn-9) reached 12.16 mg/g with 96.34% contained in Se nanoparticles (SeNPs), which was much higher than that of organic macromolecules. Furthermore, SeNPs were mainly localized outside the cell, Se-proteins were in the membrane and cytoplasmic fractions, and Se-polysaccharides were in the membrane fraction. Besides, SeLn-9 maintained a good morphology and gastrointestinal tolerance and had an enhanced antioxidant capacity. These findings make Ln-9 promising for applications in the food industry.

Accumulation and metabolism of selenium in the rare yeast Kazachstania unispora during the selenium enrichment process

Selenium (Se)-enriched yeast is a good nutritional source for human being. Kazachstania unispora (K. unispora) has shown the positive physiological functionality for human health, whose potential for Se enrichment, however, remains elusive. This study demonstrated the ability of K. unispora to convert inorganic Se to organic Se, and then comprehensively investigated the accumulation and metabolism of Se in K. unispora. The results indicated that K. unispora can effectively accumulate organic Se, of which 95% of absorbed Se was converted to organic forms. Among these organic Se, 46.17% of them was bound to protein and 16.78% was combined with polysaccharides. In addition, some of the organic Se was metabolized to selenomethionine (30.26%) and selenocystine (3.02%), during which four low-molecular weight selenometabolites were identified in K. unispora. These findings expand the scope of Se-enriched yeast species, and provide useful knowledge for further investigation of Se enrichment mechanism in K. unispora.

Biosafety and pharmacokinetic characteristics of polyethylene pyrrolidone modified nano selenium in rats

OBJECTIVE

This study aims to investigate the biocompatibility and pharmacokinetic characteristics of polyvinyl pyrrolidone-modified selenium nanoparticles (PVP-Se NPs). Understanding the biosafety of PVP-Se NPs is crucial due to their potential applications in mitigating oxidative stress-related diseases and improving drug delivery systems.

METHODS

Selenium nanoparticles were prepared using a sodium selenite solution, followed by PVP modification. Particle size analysis was conducted using dynamic light scattering (DLS), and particle morphology was observed using transmission electron microscopy (TEM). Different concentrations of PVP-Se NPs were intraperitoneally injected into SD rats, and the survival rate was observed. Liver and kidney tissues, urine, feces, and blood samples were collected at the highest safe dose, and the concentration of selenium ions was measured.

RESULTS

The average particle size of PVP-Se NPs was 278.4 ± 124.8 nm, exhibiting a semi-spherical shape. The maximum safe dose of PVP-Se NPs for intraperitoneal injection in rats was approximately 320 µg/kg. At this dose, the content of PVP-Se NPs significantly increased in the liver and kidney tissues from day 1 to day 3, in urine and feces during the first 8 h, and in blood during the first 2 h, followed by a gradual decrease.

CONCLUSION

When administered at a safe dose, PVP-Se NPs do not damage liver and kidney tissues and can be eliminated from the body through liver and kidney metabolism without accumulation.

Effect of Selenium Supplementation on Biotin and Selenobiotin Concentrations in Meyerozyma guilliermondii and Trichosporon cutaneum Cells

Numerous studies have demonstrated the efficacy of selenium compounds in preventing and treating lifestyle-related diseases such as cancer and cardiovascular disorders. The formulation of selenium-enriched supplements for humans and animals, particularly those containing selenium yeast, is highly advantageous. These products are rich in organic selenium derivatives, showing significantly higher bioavailability than inorganic forms of selenium. A particularly promising selenium analogue of sulphur-containing compounds is selenobiotin. The literature indicates that Phycomyces blakesleeanus and Escherichia coli strains can synthesise this compound. This research aimed to evaluate the effect of selenium supplementation on the biosynthesis of biotin and selenobiotin in Trichosporon cutaneum and Meyerozyma guilliermondii. The results have the potential to advance biotechnological approaches for the production of selenobiotin for various applications. A method based on affinity chromatography was used to quantify selenobiotin. The results confirmed that both yeast strains could synthesise selenobiotin in addition to biotin. In M. guilliermondii cells, selenobiotin accounted for up to 17.3% of the total biotin vitamer fraction. In comparison, in T. cutaneum cells, it accounted for up to 28.4% of the sum of biotin and its analogues. The highest levels of selenobiotin were observed in cells cultured with selenomethionine.

Selenium-enriched yeast, a selenium supplement, improves the rheological properties and processability of dough: From the view of yeast metabolism and gluten alteration

This study investigated the effect mechanism of selenium (Se)-enriched yeast on the rheological properties of dough from the perspective of yeast metabolism and gluten alteration. As the yeast Se content increased, the gas production rate of Se-enriched yeast slowed down, and dough viscoelasticity decreased. The maximum creep of Se-enriched dough increased by 29%, while the final creep increased by 54%, resulting in a softer dough. Non-targeted metabolomics analyses showed that Se inhibited yeast energy metabolism and promoted the synthesis of stress-resistance related components. Glutathione, glycerol, and linoleic acid contributed to the rheological property changes of the dough. The fractions and molecular weight distribution of protein demonstrated that the increase in yeast Se content resulted in the depolymerization of gluten. The intermolecular interactions, fluorescence spectrum and disulfide bond analysis showed that the disruption of intermolecular disulfide bond induced by Se-enriched yeast metabolites played an important role in the depolymerization of gluten.

Selenomethionine supplementation mitigates fluoride-induced liver apoptosis and inflammatory reactions by blocking Parkin-mediated mitophagy in mice

As an environmental pollutant, fluoride-induced liver damage is directly linked to mitochondrial alteration and oxidative stress. Selenium's antioxidant capacity has been shown to alleviate liver damage. Emerging research proves that E3 ubiquitin ligase Park2 (Parkin)-mediated mitophagy may be a therapeutic target for fluorosis. The current study explored the effect of diverse selenium sources on fluoride-caused liver injury and the role of Parkin-mediated mitophagy in this intervention process. Therefore, this study established a fluoride-different selenium sources co-intervention wild-type (WT) mouse model and a fluoride-optimum selenium sources co-intervention Parkin gene knockout (Parkin-/-) mouse model. Our results show that selenomethionine (SeMet) is the optimum selenium supplementation form for mice suffering from fluorosis when compared to sodium selenite and chitosan nano‑selenium because mice from the F-SeMet group showed more closely normal growth and development levels of liver function, antioxidant capacity, and anti-inflammatory ability. Explicitly, SeMet ameliorated liver inflammation and cell apoptosis in fluoride-toxic mice, accomplished through downregulating the mRNA and protein expression levels associated with mitochondrial fusion and fission, mitophagy, apoptosis, inflammatory signalling pathway of nuclear factor-kappa B (NF-κB), reducing the protein expression levels of PARKIN, PTEN-induced putative kinase1 (PINK1), SQSTM1/p62 (P62), microtubule-associated protein light chain 3 (LC3), cysteinyl aspartate specific proteinase 3 (CASPAS3), as well as restraining the content of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), and interferon-γ (IFN-γ). The Parkin-/- showed comparable positive effects to the SeMet in the liver of fluorosis mice. The structure of the mitochondria, mRNA, protein expression levels, and the content of proinflammatory factors in mice from the FParkin-/- and F + SeMetParkin-/- groups closely resembled those in the F + SeMetWT group. Overall, the above results indicated that SeMet could alleviate fluoride-triggered inflammation and apoptosis in mice liver via blocking Parkin-mediated mitophagy.

Combined metabolome and transcriptome analysis reveals the key pathways involved in the responses of soybean plants to high Se stress

High selenium (Se) levels can induce toxicity, inhibit growth, and affect gene expression and metabolite content in plants. However, the molecular mechanism by which high Se stress affects soybean plants remains unclear. This study examined the responses of soybean leaves and roots to high Se stress using transcriptome and metabolome analyses. High Se stress significantly inhibited soybean root growth, reduced leaf area, and affected the antioxidant enzyme system in roots and leaves, resulting in the accumulation of malondialdehyde (MDA). High Se stress increased indoleacetic acid (IAA), abscisic acid (ABA), jasmonic acid (JA), and salicylic acid (SA) in the roots by 3.34-fold, 8.94-fold, 0.25-fold, and 5.65-fold, respectively. Similarly, high Se stress increased IAA, ABA, JA, and SA in the leaves by 1.96-fold, 10.54-fold, 2.03-fold, and 4.22-fold, respectively. In addition, high Se stress affected ion absorption and transport in soybean plants. Transcriptome results showed that there were 10,038 differentially expressed genes (DEGs) in soybean roots and 5811 DEGs in leaves, which affected the expression of antioxidant enzymes, ion transport and hormone-related genes. Metabolome results revealed that there were 277 differentially expressed metabolites (DEMs) in soybean leaves and 312 DEMs in roots. Soybean roots and leaves were significantly enriched in the "β-alanine metabolism" pathway under high Se stress, with differential expression of Aldehyde dehydrogenase (ALDH), Amine oxidase (AO), and other related genes, thereby relieving oxidative stress. This study improves our understanding of the molecular mechanisms underlying the responses of soybean plants to high Se stress and provides a basis for breeding Se-enriched soybean plants.

The role of reactive oxygen species in severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) infection-induced cell death

Coronavirus disease 2019 (COVID-19) represents the novel respiratory infectious disorder caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and is characterized by rapid spread throughout the world. Reactive oxygen species (ROS) account for cellular metabolic by-products, and excessive ROS accumulation can induce oxidative stress due to insufficient endogenous antioxidant ability. In the case of oxidative stress, ROS production exceeds the cellular antioxidant capacity, thus leading to cell death. SARS-CoV-2 can activate different cell death pathways in the context of infection in host cells, such as neutrophil extracellular trap (NET)osis, ferroptosis, apoptosis, pyroptosis, necroptosis and autophagy, which are closely related to ROS signalling and control. In this review, we comprehensively elucidated the relationship between ROS generation and the death of host cells after SARS-CoV-2 infection, which leads to the development of COVID-19, aiming to provide a reasonable basis for the existing interventions and further development of novel therapies against SARS-CoV-2.

Exploring the lipids, carotenoids, and vitamins content of Rhodotorula glutinis with selenium supplementation under lipid accumulating and growth proliferation conditions

BACKGROUND

Rhodotorula glutinis, a specific type of yeast, has been recognised as a superior resource for generating selenium-enriched biomass that possesses exceptional nutritional and functional attributes. The purpose of this investigation was to assess the effect of sodium selenite at different concentrations on lipid and carotenoid synthesis, as well as the growth of R. glutinis.

METHODS

The lipid's fatty acid composition was determined using gas chromatography (GC). The vitamins were detected by high-performance liquid chromatography (HPLC). Transmission electron microscopy was used to detect the structural modification of yeast cells caused by the addition of sodium selenite to the growth medium, as well as the accumulation of elemental selenium in the yeast cells.

RESULTS

The yeast cells demonstrated the ability to endure high concentrations of sodium selenite under lipid accumulation (LAM) and growth-promoting (YPD) conditions. 25.0 mM and 30.0 mM, respectively, were published as the IC50 values for the LAM and YPD conditions. In both growth media, 1 mM sodium selenite boosted lipid synthesis. Lipid accumulation increased 26% in LAM to 11.4 g/l and 18% in YPD to 4.3 g/l. Adding 1 mM and 3 mM sodium selenite to YPD medium increased total and cellular carotenoids by 22.8% (646.7 µg/L and 32.12 µg/g) and 48.7% (783.3 µg/L and 36.43 µg/g), respectively. Palmitic acid was identified as the most abundant fatty acid in all treatments, followed by oleic acid and linoleic acid. The concentrations of water soluble vitamins (WSV) and fat soluble vitamins (FSV) were generally significantly increased after supplementation with 1.0 mM sodium selenite. TEM examination revealed a significant reduction in lipid bodies accumulation in the yeast cells when sodium selenite was added to lipid-promoting environments. This decline is accompanied by an augmentation in the formation of peroxisomes, indicating that selenium has a direct impact on the degradation of fatty acids. In addition, autophagy appears to be the primary mechanism by which selenium ions are detoxified. Additionally, intracellular organelles disintegrate, cytoplasmic vacuolization occurs, and the cell wall and plasma membrane rupture, resulting in the discharge of cytoplasmic contents, when a high concentration of sodium selenite (20.0 mM) is added. Also, the presence of numerous electron-dense granules suggests an intracellular selenium-detoxification pathway.

CONCLUSION

This study proposes the use of YPD with 1 mM sodium selenite to cultivate selenium-enriched biomass from R. glutinis. This approach leads to heightened lipid levels with higher accumulation of oleic, linoleic and linolenic acids, carotenoids, and vitamins. Hence, this biomass has the potential to be a valuable additive for animal, fish, and poultry feed. Furthermore, explain certain potential factors that indicate the impact of selenium in reducing the accumulation of lipid droplets in R. glutinis during lipogenesis, as detected through TEM examination.

Micelle-Assisted C(sp2)-H Functionalization for C-Se and C-X Bond Formation in the Aqueous Medium

An environmentally sustainable, versatile, and cost-effective approach for C-Se and C-X (X = I, Br, and Cl) bond formation through C-H functionalization assisted by micellar catalysis in water is developed. The reaction utilizes a minimum amount of diorganyl diselenides and potassium halides for the respective functionalizations. The present protocol was suitable for scale-up synthesis, which directly provided the desired selenylated products without the need for chromatographic purification, in sufficient purity. The aqueous micellar catalysis system was reusable for up to 5 reaction cycles without compromising the reaction yield.

Selenium Nanoparticles Regulate Antioxidant Enzymes and Flavonoid Compounds in Fagopyrum dibotrys

Fagopyrum dibotrys is a herbal plant. Selenium (Se) is a beneficial element for plants; selenium nanoparticles (SeNPs) are gaining importance in food and agriculture due to their low toxicity and high activity. This study revealed that foliar application of SeNPs enhanced superoxide dismutase, glutathione peroxidase, and peroxisome activities and significantly enhanced the flavonoid compound content in F. dibotrys. SeNPs with a concentration of 5.0 mg L-1 also promoted the growth of F. dibotrys. The foliar application of SeNPs could be absorbed by pores in leaves of F. dibotrys and mainly transformed to selenomethionine (32.5-43.2%) and selenocysteine (23.4-38.4%) in leaves and tubers of F. dibotrys. Consequently, this study offers a profound understanding of plants' uptake and biotransformation of SeNPs. Furthermore, the findings of this study have suggested that SeNPs can be applied to improve the quantity and quality of the herbal plant of F. dibotrys.

The Role of the Trace Element Selenium in Inflammatory Bowel Disease

One set of chronic gastrointestinal disorders called inflammatory bowel disease (IBD) is defined by persistent, non-specific inflammation. Abdominal pain, hematochezia, diarrhea, and other symptoms are among its clinical signs. Currently, managing and treating IBD remains a significant challenge. Patients with IBD frequently have deficits in trace elements. Selenium (Se) is one of the necessary trace elements for normal organismal function. It has several regulatory effects, including anti-oxidation, anti-inflammatory, and defensive properties, via inducing the synthesis of selenoproteins. Patients with IBD have been shown to have lower Se levels in epidemiologic research studies. Several experimental models of IBD suggest that Se or selenoproteins play a key role in microinflammation. We discuss the relationship between Se and IBD in this review, with an emphasis on a summary of potential mechanisms of action and applications of Se in IBD.

Selenopolysaccharide Isolated from Lentinula edodes Mycelium Affects Human T-Cell Function

Lentinula edodes polysaccharides are natural immunomodulators. SeLe30, analyzed in this study, is a new mixture of selenium-enriched linear 1,4-α-glucans and 1,3-β- and 1,6-β-glucans isolated from L. edodes mycelium. In the present study, we evaluated its immunomodulatory properties in human T cells. Peripheral blood mononuclear cells (PBMCs) and T cells were isolated from healthy donors' buffy coats. The effects of SeLe30 on CD25, CD366, and CD279 expression, the subsets of CD8+ T cells, and IFN-γ, IL-6, and TNF-α production were analyzed. SeLe30 downregulated CD25, CD279, and CD366 expression on T cells stimulated by the anti-CD3 antibody (Ab) and upregulated in unstimulated and anti-CD3/CD28-Abs-stimulated T cells. It increased the percentage of central memory CD8+ T cells in unstimulated PBMCs and naïve and central memory T cells in anti-CD3-Ab-stimulated PBMCs. SeLe30 decreased the number of central memory and naïve CD8+ T cells in anti-CD3/CD28-stimulated T cells, whereas, in PBMCs, it reduced the percentage of effector memory CD8+ T cells. Moreover, SeLe30 upregulated cytokine production. SeLe30 exhibits context-dependent effects on T cells. It acts on unstimulated T cells, affecting their activation while increasing the expression of immune checkpoints, which sensitizes them to inhibitory signals that can silence this activation. In the case of a lack of costimulation, SeLe30 exhibits an inhibitory effect, reducing T-cell activation. In cells stimulated by dual signals, its effect is further enhanced, again increasing the "safety brake" of CD366 and CD279. However, the final SeLe30 effect is mediated by its indirect impacts by altering interactions with other immune cells.

Highly aligned myotubes formation of piscine satellite cells in 3D fibrin hydrogels of cultured meat

Currently, various cultured meat products, including chicken, beef and pork, have been developed. However, established methods for production cultured fish meat with highly aligned myotubes are still lack. In this study, we introduced a culture method based on high-biocompatibility fibrin hydrogels with an easy-to-use tissue mold for obtaining cultured fish fillets that closely mimicked the structure of natural fish fillets. Results showed that highly aligned myotubes were observed within the muscle bundles culturing in the tissue mold. The myotube fusion index was also increased to 72.65 %. Furthermore, key differentiation genes (desmin, myosin light chain kinase, myocilin) were up-regulated in the tissue mold group. Transcriptomic analysis further supported the effectiveness of method in promoting myoblast fusion. Stiffness of the muscle bundles was also positively impacted by the tissue mold. Ultimately, sensory and nutritional characteristics of natural and cultured fish fillets were compared, revealing that cultured fish fillets prepared from the tissue mold was closer to natural fish fillets in sensory characteristic, and there were still some gaps with natural fish fillets in nutritional characteristic. Overall, our findings suggest that optimizing culture methods can help bridge some gaps between natural meat and cultured meat, facilitating the development of cultured fish meat.