Food Chemistry of Selenium and Controversial Roles of Selenium in Affecting Blood Cholesterol Concentrations

The Effect of a Nutritional Intervention with the Use of Biofortified Beef Meat on Selected Biochemical Parameters in Blood from Older Adults

This study aimed to investigate the effects of meat biofortified with antioxidants and canola oil on the health of older adults through blood parameters. Eighty institutionalized older persons were divided into four groups who received the following treatments: C-control meat with 46 µg/kg of meat with selenium, 3.80 g/kg of meat with vitamin E and 0.78 g/100 g of meat with conjugated linoleic acid (CLA); A-antioxidant meat with 422 µg/kg of meat with selenium, 7.65 g/kg of meat with vitamin E and 0.85 g/100 g of meat with CLA; O-oil meat with 57 µg/kg of meat with selenium, 3.98 g/kg of meat with vitamin E and 1.27 g/100 g of meat with CLA; OA-oil and antioxidant meat with 367 µg/kg of meat with selenium, 7.78 g/kg of meat with vitamin E and 1.08 g/100 g of meat with CLA. Blood samples were collected at 0, 45 and 90 days after the start of meat intake. Older adults who consumed ANT (A and AO) meat had higher concentrations of selenium (p = 0.039), vitamin E and HDL (higher concentrations of high-density lipoprotein, p = 0.048) in their blood. This study demonstrates that the consumption of Se- and vitamin E-biofortified meat increases the concentration of these metabolites in blood from older adults.

SKN-1 is indispensable for protection against Aβ-induced proteotoxicity by a selenopeptide derived from Cordyceps militaris

Oxidative stress (OS) and disruption of proteostasis caused by aggregated proteins are the primary causes of cell death in various diseases. Selenopeptides have shown the potential to control OS and alleviate inflammatory damage, suggesting promising therapeutic applications. However, their potential function in inhibiting proteotoxicity is not yet fully understood. To address this gap in knowledge, this study aimed to investigate the effects and underlying mechanisms of the selenopeptide VPRKL(Se)M on amyloid β protein (Aβ) toxicity in transgenic Caenorhabditis elegans. The results revealed that supplementation with VPRKL(Se)M can alleviate Aβ-induced toxic effects in the transgenic C. elegans model. Moreover, the addition of VPRKL(Se)M inhibited the Aβ aggregates formation, reduced the reactive oxygen species (ROS) levels, and ameliorated the overall proteostasis. Importantly, we found that the inhibitory effects of VPRKL(Se)M on Aβ toxicity and activation of the unfolded protein are dependent on skinhead-1 (SKN-1). These findings suggested that VPRKL(Se)M is a potential bioactive agent for modulating SKN-1, which subsequently improves proteostasis and reduces OS. Collectively, the findings from the current study suggests VPRKL(Se)M may play a critical role in preventing protein disorder and related diseases.

In vitro digestion and fecal fermentation of selenocompounds: impact on gut microbiota, antioxidant activity, and short-chain fatty acids

Selenium bioavailability is critically influenced by gut microbiota, yet the interaction dynamics with selenocompounds remain unexplored. Our study found that L-Selenomethionine (SeMet) and Se-(Methyl)seleno-L-cysteine (MeSeCys) maintained stability during in vitro gastrointestinal digestion. In contrast, Selenite and L-Selenocystine (SeCys2) were degraded by approximately 13% and 35%. Intriguingly, gut microflora transformed MeSeCys, SeCys2, and Selenite into SeMet. Moreover, when SeCys2 and Selenite incubated with gut microbiota, they produced red selenium nanoparticles with diameters ranging between 100 and 400 nm and boosted glutathione peroxidase activity. These changes were positively associated with an increased relative abundance of unclassified_g__Blautia (Family Lachnospiraceae), Erysipelotrichaceae_UCG-003 (Family Erysipelatoclostridiaceae), and uncultured_bacterium_g__Subdoligranulum (Family Ruminococcaceae). Our findings implied that differential microbial sensitivities to selenocompounds, potentially attributable to their distinct mechanisms governing selenium uptake, storage, utilization, and excretion.

Removal and recycling of aqueous selenite anions using cobalt-based metal-organic-framework coated on multi-walled carbon nanotubes composite membrane

The utilization of selenium as a novel functional material is rapidly expanding, and the retrieval of selenium from waste containing selenium is gaining recognition in the industry. This study prepared a novel composite membrane coated with the cobalt-based metal-organic framework coated on multi-walled carbon nanotubes (Co-MOF@MWCNTs). The MWCNTs served as the skeleton to support the active components of Co-MOF, which enabled efficient removal and resource utilization of liquid selenite (SeO32-). The morphology, structure, and composition of the prepared membrane were characterized using field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), etc.. Applying a permeate flux of 67.08 L m-2 h-1, the SeO32- removal efficiency of the composite membrane reached up to 92.2%. The composite membrane containing CoSeO4 can be used as an electrocatalytic oxygen evolution catalyst. Density functional theory calculations and electrochemical analysis showed that the conversion from O* to OOH* was a rate-determining step. Under 1.0 M KOH conditions, the lowest overpotential for Co-MOF@MWCNTs-40 at 10 mA cm-2 was 360 mV. In this study, the process of selenium resource utilization and the mechanism of SeO32- removal by Co-MOF@MWCNTs are revealed. It demonstrates that membrane-based sequestration of SeO32- can provide a viable approach for SeO32- removal and utilization in wastewater.

Therapeutic Potential of Selenium Nanoparticles on Letrozole-Induced Polycystic Ovarian Syndrome in Female Wistar Rats

Polycystic ovarian syndrome (PCOS) is considered the most frequent gynecological endocrine disorder that causes anovulatory infertility. The current study aimed to investigate the potential significance of selenium nanoparticles (SeNPs), an IL-1 inhibitor, in the treatment of letrozole-induced PCOS in rats that satisfied the metabolic and endocrine parameters found in PCOS patients. Letrozole (2 ppm, per orally, p.o.) was given orally to female Wistar rats for 21 days to develop PCOS. After PCOS induction, rats were given SeNPs (25 ppm/day, p.o.), SeNPs (50 ppm/day, p.o.), or metformin (2 ppm/day, p.o.) for 14 days. PCOS was associated with an increase in body weight, ovarian weight, ovarian size, and cysts, as well as an increase in blood testosterone, luteinizing hormone (LH), and insulin, glycaemia, and lipid profile levels. The SeNP administration decreased all of these variables. Furthermore, SeNPs significantly reduced letrozole-induced oxidative stress in the ovaries, muscles, and liver by decreasing elevated levels of malondialdehyde and total nitrite while raising suppressed levels of superoxide dismutase and catalase. SeNPs increased the amounts of the protective proteins Kelch-like ECH-associated protein 1 (Keap-1), nuclear factor erythroid 2-related factor 2 (Nrf2), and OH-1. It was depicted from the study that SeNPs reduce the upregulation of inflammatory cytokines that are interleukin 6 (IL-6), tumour necrosis factor α (TNF-α), and the interleukin 1 (IL-1). Our findings show that SeNPs, through their antioxidant and anti-inflammatory characteristics, alleviate letrozole-induced PCOS.

Selenium Modification of Natural Products and Its Research Progress

The selenization of natural products refers to the chemical modification method of artificially introducing selenium atoms into natural products to interact with the functional groups in the target molecule to form selenides. Nowadays, even though scientists in fields involving organic selenium compounds have achieved numerous results due to their continuous investment, few comprehensive and systematic summaries relating to their research results can be found. The present paper summarizes the selenization modification methods of several kinds of important natural products, such as polysaccharides, proteins/polypeptides, polyphenols, lipids, and cyclic compounds, as well as the basic principles or mechanisms of the selenizing methods. On this basis, this paper explored the future development trend of the research field relating to selenized natural products, and it is hoped to provide some suggestions for directional selenization modification and the application of natural active ingredients.

Understanding the Effect of Single Atom Cationic Defect Sites in an Al2O3 (012) Surface on Altering Selenate and Sulfate Adsorption: An Ab Initio Study

Adsorption is a promising under-the-sink selenate remediation technique for distributed water systems. Recently it was shown that adsorption induced water network re-arraignment control adsorption energetics on the α - Al 2 O 3 (012) surface. Here, we aim to elucidate the relative importance of the water network effects and surface cation identity on controlling selenate and sulfate adsorption energy using density functional theory calculations. Density functional theory (DFT) calculations predicted the adsorption energies of selenate and sulfate on nine transition metal cations (Sc-Cu) and two alkali metal cations (Ga and In) in the α - Al 2 O 3 (012) surface under simulated acidic and neutral pH conditions. We find that the water network effects had larger impact on the adsorption energy than the cationic identity. However, cation identity secondarily controlled adsorption. Most cations decreased the adsorption energy weakening the overall performance, the larger Sc and In cations enabled inner-sphere adsorption in acidic conditions because they relaxed outward from the surface providing more space for adsorption. Additionally, only Ti induced Se selectivity over S by reducing the adsorbing selenate to selenite but not reducing the sulfate. Overall, this study indicates that tuning water network structure will likely have a larger impact than tuning cation-selenate interactions for increasing adsorbate effectiveness.

Selenium-enriched foods and their ingredients: As intervention for the vicious cycle between autophagy and overloaded stress responses in Alzheimer's disease

Dysfunctional autophagy induced by excessive reactive oxygen species (ROS) load and inflammation accelerates the development of Alzheimer's disease (AD). Recently, there has been an increasing interest in selenium-enriched ingredients (SEIs), such as selenoproteins, selenoamino acids and selenosugars, which could improve AD through antioxidant and anti-inflammation, as well as autophagy modulating effects. This review indicates that SEIs eliminate excessive ROS by activating the nuclear translocation of nuclear factor erythroid2-related factor 2 (Nrf2) and alleviate inflammation by inhibiting the mitogen-activated protein kinases (MAPKs)/nuclear factor kappa-B (NF-κB) pathway. Furthermore, they can activate the adenosine 5'-monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway, and subsequently promote amyloid beta (Aβ) clearance and reduce memory impairments. SEIs are ubiquitous in many plants and microorganisms, such as Brassicaceae vegetables, yeast, and mushroom. Enzymatic hydrolysis, as well as physical processing, such as thermal, high pressure and microwave treatment, are the main techniques to modify the properties of dietary selenium. This work highlights the fact that SEIs can inhibit inflammation and oxidative stress and provides evidence that supports the potential use of these dietary materials to be a novel strategy for improving AD.

Selenium in Bodily Homeostasis: Hypothalamus, Hormones, and Highways of Communication

The ability of the body to maintain homeostasis requires constant communication between the brain and peripheral tissues. Different organs produce signals, often in the form of hormones, which are detected by the hypothalamus. In response, the hypothalamus alters its regulation of bodily processes, which is achieved through its own pathways of hormonal communication. The generation and transmission of the molecules involved in these bi-directional axes can be affected by redox balance. The essential trace element selenium is known to influence numerous physiological processes, including energy homeostasis, through its various redox functions. Selenium must be obtained through the diet and is used to synthesize selenoproteins, a family of proteins with mainly antioxidant functions. Alterations in selenium status have been correlated with homeostatic disturbances in humans and studies with animal models of selenoprotein dysfunction indicate a strong influence on energy balance. The relationship between selenium and energy metabolism is complicated, however, as selenium has been shown to participate in multiple levels of homeostatic communication. This review discusses the role of selenium in the various pathways of communication between the body and the brain that are essential for maintaining homeostasis.

Nanozyme-encoded luminescent detection for food safety analysis: An overview of mechanisms and recent applications

With the rapid growth in global food production, delivery, and consumption, reformative food analytical techniques are required to satisfy the monitoring requirements of speed and high sensitivity. Nanozyme-encoded luminescent detections (NLDs) integrating nanozyme-based rapid detections with luminescent output signals have emerged as powerful methods for food safety monitoring, not only because of their preeminent performance in analysis, such as rapid, facile, low background signal, and ultrasensitive, but also due to their strong attractiveness for future sensing research. However, the lack of a full understanding of the fundamentals of NLDs for food safety detection technologies limits their further application. In this review, a systematic overview of the mechanisms of NLDs and their applications in the food industry is summarized, which covers the nanozyme-mimicking types and their luminescent signal generation mechanisms, as well as their applications in monitoring common foodborne contaminants. As demonstrated by previous studies, NLDs are bridging the gap to practical-oriented food analytical technologies and various opportunities to improve their food analytical performance to be considered in the future are proposed.

Discovery of Se-containing flavone in Se-enriched green tea and the potential application value in the immune regulation

Selenium (Se)-enriched green tea has been recognized as a possible source of supplemental Se, while the structural and physiological activities of Se-containing flavone are still unclear. In this study, a Se-containing flavone was isolated from Se-enriched green tea by high-speed counter-current chromatography (HSCCC) and characterized through UHPLC-Q-Orbitrap, FT-IR and NMR. Results proved that HSeO₃^- can be combined with the alcohol hydroxyl of 2-phenylchromone in flavone and the content of Se-containing flavone in tea was 15690.4 μg L^-1. Additionally, Se-containing flavone can effectively inhibit the production of nitric oxide (NO), and downregulate expression of TNF-α and IL-6. Compared with regular flavone extracted from green tea (43.24 pg mL^-1), release of IL-10 was higher in Se-containing flavone group (53.37 pg mL^-1), indicating that Se-containing flavone played an important role in the process of severe inflammatory injury. The results indicated that Se-containing flavone was an attractive natural ingredient for developing novel functional foods.

Rational construction of a new water soluble turn-on colorimetric and NIR fluorescent sensor for high selective Sec detection in Se-enriched foods and biosystems

As a naturally occurring amino acid, selenocysteine (Sec) plays a key role in a variety of cellular functions and Se-enriched foods. In this work, a robust water soluble fluorescence turn-on near-infrared (NIR) sensor NIR-Sec was constructed for Sec detection over biothiols in Se-enriched foods. Specifically, NIR-Sec contains a readily prepared water soluble NIR dicyanoisophorone fluorophore and a well-known response-site 2,4-dinitrobenzenesulfonyl moiety with strong intramolecular charge transfer (ICT) effect to quench the fluorescence intensity of NIR fluorophore. Upon addition of Sec, the NIR dicyanoisophorone fluorophore was released and a bright red emission at 663 nm was observed. Moreover, NIR-Sec toward Sec exhibited rapid response time (∼1 min), a large stoke shift (183 nm), and high selectivity and sensitivity (LOD: 52 nM). Impressively, NIR-Sec was successfully employed to detect and image Sec in Se-enriched foods and shrimp, indicating NIR-Sec could provide a robust tool for investigating the role of Sec in complex real-food samples.

Selenium Supplementation during Puberty and Young Adulthood Mitigates Obesity-Induced Metabolic, Cellular and Epigenetic Alterations in Male Rat Physiology

Selenium (Se) role in obesity is not clear. In addition, information on Se’s role in male physiology, specifically in obesity, is scarce. We conducted this study to evaluate the efficacy of Se supplementation, specifically during puberty until young adulthood, against obesity-induced deregulation of metabolic, cellular, and epigenetic parameters in epididymal fat and/or sperm cells in a rat model. High-fat-diet consumption by male rats during puberty and young adulthood significantly increased body weight, adipocyte size, oxidative stress, deregulated expression of genes associated with inflammation (Adiponectin, IL-6, TNF-α), adipogenesis (CEBPα), estrogen biosynthesis (CYP19) and epigenetic processes in epididymal adipose tissue (Dnmt3a), as well as altered microRNA expression vital for spermatogenesis in sperm cells (miR-15b and miR-497). On the other hand, Se supplementation significantly decreased oxidative stress and mitigated these molecular/epigenetic alterations in epididymal adipose tissue or sperm cells. Our results indicate that selenium supplementation during puberty/young adulthood could improve male physiology in the context of obesity. In addition, it suggests that Se could potentially positively affect offspring health.

Selenium-agarose hybrid hydrogel as a recyclable natural substrate for selenium-enriched cultivation of mung bean sprouts

Selenium (Se) is an essential trace element for human beings and animals. Traditional plant Se enrichment technology suffers from selenium pollution. Herein, environmentally friendly Se-agarose (Se-Agar) hybrid hydrogels are prepared by simply mixing agar with different Se species including selenocarrageenan (SeCA), selenite and Se yeast under heating and stirring for 0.5 h without any other reagent. Such Se-Agar hybrid hydrogels with excellent biocompatibility were used as natural substrates for the cultivation of Se-enriched mung bean sprouts. Compared with Se yeast, SeCA and selenite show a better Se enrichment effect on mung bean sprouts. Furthermore, the growth indices including plant weight and plant height of mung bean sprouts were investigated with different concentrations and sources of Se. Notably, the Se-Agar hybrid hydrogels could be easily regenerated and reused for multiple cycles. The results indicated that Se-Agar hybrid hydrogels as recyclable natural substrates offer a simple, sustainable and affordable strategy for plant Se enrichment.