Se Supplementation Research Articles

Erythrocyte Selenium as a Potential Key Indicator for Selenium Supplementation in Low-Selenium Populations: A Selenium Supplementation Study Based on Wistar Rats

Background: Selenium (Se) is an essential trace element for maintaining human health, with significant antioxidant and immunoregulatory functions. Inadequate Se intake may be associated with Keshan disease, Kashin–Beck disease, and hypothyroidism. However, effective indicators for scientifically guiding Se supplementation in Se-deficient populations are still lacking. Objectives: This study aims to explore the dynamic distribution of Se across various nutritional biomarkers and major organs in rats through a Se supplementation experiment, as well as the pairwise correlations between them, in order to identify reliable nutritional indicators for evaluating Se levels in the body. Methods: Se levels in hair, blood, and major tissues and organs were determined by atomic fluorescence spectrometry, and glutathione peroxidase (GSH-Px) levels were measured using an ELISA. Results: Se supplementation significantly increased Se levels in rat blood, hair, and major organs, as well as GSH-Px levels in blood. Se primarily accumulated in the liver and kidneys, followed by myocardium, spleen, and muscles. Serum and plasma Se were found to be the best indicators of short-term Se intake, while erythrocyte Se levels showed a stronger correlation with Se levels in tissues and organs, making it a better marker for assessing long-term Se nutritional status compared to hair Se. Conclusions: This study demonstrates the potential of erythrocyte Se levels as an indicator for evaluating long-term Se nutritional status, providing scientific evidence for Se nutritional assessments.

Selenium, selenoprotein P and autoantibodies to selenium transport proteins in Swedish heart failure patients - a pilot study in preparation for a randomized supplementation trial

Abstract Background Severe selenium (Se) deficiency, as in Keshan disease, is associated with a fatal form of heart failure (HF), preventable and reversible with Se supplementation. Recent studies have identified Se deficiency as highly prevalent, up to 70%, among patients with HF, and associated with a poorer prognosis. Observational data suggest that Se concentrations <100 μg/L in HF patients and selenoprotein P (SELENOP) concentrations <4.1 mg/L are associated with increased mortality and hospital readmissions. Further, in recent studies, natural autoantibodies (aAb) towards SELENOP have been detected with the potential to disrupt transportation mechanisms. While the evidence does not yet support Se supplementation for HF patients in clinical practice, it does justify the initiation of large, well-designed randomized controlled trials (RCTs). Purpose To assess and confirm the previously reported high prevalence of Se deficiency, measured by both Se and SELENOP concentrations in HF patients and exploring the prevalence of aAb to SELENOP. This will provide a rationale for further, adequately powered and designed, studies of Se supplementation in HF patients. Methods A total of 527 blood samples were obtained from a nationwide Swedish HF biobank, sourced from various hospitals. In those samples; serum Se concentrations in 455 samples using mass spectrometry, SELENOP concentrations in 520 samples using an immunoassay, and prevalence of aAb to SELENOP in 513 samples using an immunoluminometric assay were analyzed. In addition, SELENOP concentrations in 320 HF patients from a Swedish single-center study were analysed. Results The study population had a mean age of 70.3 (±11.8) years (30.5% women). Prevalence of Se deficiency was higher than previously reported. In the national HF registry, the median Se concentration was 75 µg/L and Se concentrations below 100 μg/L were found in 426 (93%) samples. SELENOP concentrations had a median of 3.5 mg/L, corresponding to ~80 μg/L Se, with 80.5% of subjects below SELENOP-concentration of 4.3 mg/L (corresponding to ~100 μg/L Se). In the confirmatory single-center study, the SELENOP median concentration was 3.1 mg/L, corresponding to Se concentrations of ~70 µg/L and SELENOP -concentrations below 4.3 mg/L (corresponding to approximately 100 μg/L Se) were observed in 89.4% of the study population. Further, aAb to SELENOP were prevalent in 9.7% of the population, compared to approximately 1% in healthy subjects. Conclusion This pilot study demonstrates a high prevalence of suboptimal Selenium status in Swedish HF patients which further underscores the need for suitably designed intervention studies to address the efficacy and safety of Se supplementation which can possibly constitute an inexpensive, safe and readily available treatment option for HF patients.

Evaluation of selenocysteine contents in Se-enriched yogurt by Utilizing online post column derivative − High-Performance liquid chromatography

This study demonstrated a novel method using online post-column derivatization high-performance liquid chromatography (PCD-HPLC) to evaluate selenocysteine (SeC) in Se-enriched yogurt. The liquid chromatography process utilized a C18 column. The mobile phase A was composed of 4.0 mM borate buffer adjusted to pH 5.0, while mobile phase B was a 50:50 (v/v) mixture of methanol and acetonitrile. The mobile phases were combined at a ratio of 70:30, with a flow rate of 1 mL min−1. SeC was derivatized to bis-Fmoc selenocystine after separation, using a PCD solution (0.03 mM Fmoc, pH 10, 20 mM borate buffer, and 1.0 mL min−1 flow rate) and detected with a photodiode array detector (DAD) for sensitivity enhancement. The method exhibited excellent linearity (0.023 to 0.20 mg L-1, r2 = 0.9996), with a low LOD and LOQ of 0.018 mg L-1 and of 0.040 mg L-1, respectively. Repeatability and reproducibility were satisfactory, with recoveries of 95.50 % ± 1.49 % (the proposed PCD-HPLC) and 94.33 % ± 0.44 % (sample preparation). This method effectively analyzed the conversion of selenite ions (SeO32-) to SeC by lactic acid bacteria in yogurt, highlighting Se-enriched yogurt as a valuable dietary source of SeC. However, the synthesis efficiency of SeC decreased at inorganic Se supplementation levels above 1.0 mg Se L-1, potentially leading to the formation of less toxic elemental Se (Se0). Therefore, the proposed online PCD-HPLC method proves reliable for SeC analysis in Se-enriched yogurt, providing insights into Se speciation and optimizing Se enrichment processes.

Toward Cross-Species Crop Se Content Prediction Using Random Forest Modeling

Selenium is an indispensable trace element in the human body that plays an important role in maintaining life activities. The consumption of Se-rich crops provides a practical and effective way for the body to supplement Se. However, the Se content in crops is affected by the soil Se content and the interactions between other elements in the soil. In this study, the Tibetan Plateau of China was chosen as the study area. The random forest algorithm was applied to select four key indicators—selenium (Se), bioavailable phosphorus (P), cadmium (Cd), and bioavailable copper (Cu)—from 29 soil variables to predict the Se content in rapeseed, wheat, potato, pasture, and chrysanthemum crops. The results showed that, despite the rich soil Se resources in the Tibetan Plateau, only 20% of the crop samples met the national Se enrichment standard (>0.07 mg kg−1). Compared with the traditional multiple linear regression method, the random forest model is more accurate, efficient, and reliable in predicting the Se content of crops. In cross-species crop prediction, which refers to the simultaneous cultivation and analysis of multiple distinct crop species within the same agricultural setting, the random forest model demonstrated superior performance, marking a significant breakthrough in cross-species crop research. This approach effectively eliminates the tedious process of conducting repetitive individual evaluations for different crop types in the same region, highlighting its innovative significance. Meanwhile, the Tibetan Plateau, known as the “Roof of the World”, is also of great research value. These results provide valuable references for the planning and management of Se-enriched farmlands, which will help improve the yield and quality of Se-enriched crops and promote the growth of farmers’ interests.

Evaluation of Two Levels of Trace Mineral Supplementation to Beef Calves Prior to Weaning.

In this 2-year study, approximately 84 days prior to weaning, 24 calves/year (Angus × Hereford) were randomly assigned to one of two treatments: trace mineral (Cu, Se, and Zn) supplementation following NASEM (2016) recommendations (Control) or trace mineral supplementation above NASEM (2016) recommendations (Super). Calves were individually fed, and trace minerals were provided in 0.5 kg of dry distiller's grains three times weekly. Body weight (BW), blood, and liver samples were collected on d 0 and at weaning (d 84). Additional BW and blood samples were collected post-weaning on d 85, 87, 88, 91, 95, and 99 during the preconditioning phase. Initial liver concentrations of Se, Cu, and Zn were similar between treatments (p ≥ 0.69). At weaning, a year effect (p < 0.001) and a tendency for treatment × year effect (p = 0.09) were observed for Cu liver concentration. In year 2, but not in year 1, calves assigned to the Super treatment tended to have greater liver Cu concentration than calves assigned to the Control treatment. Except for Cu, a notoriously limited trace mineral in multiple geographical locations, the supplementation of trace minerals above the NASEM (2016) recommendations did not improve the mineral status of calves in this environment.

Efficacy of two different forms of selenium towards reduction of arsenic toxicity and accumulation in Cicer arietinum L.

Arsenic migration from soil to crop plants and subsequently human consumption of contaminated foodstuffs is a serious threat for society. In the present study, two oxidation states of selenium [Se(0) and Se(VI)] were used to check their efficacy towards amelioration of arsenic toxicity in chickpeas (Cicer arietinum L.). Three different concentrations (1, 5, and 10 mg/L) of both oxidation states of selenium were applied separately and in combination against a fixed dose (10 mg/L) of arsenic [(As(V)] treatment on chickpea seedlings. Further, seed germination and seedling growth attributes, oxidative stress, and antioxidant defense under different treatments were analyzed. The changes in anatomical structures and arsenic accumulation in different parts of seedlings were also studied. Results revealed that increased generation of oxidative stress affected physiobiochemical parameters of seedlings and diminished plant growth and deformation in vascular bundles under arsenic stress. However, the combined application of Se with As showed overall improvement in seedling growth, reduced oxidative stress, and organized vascular bundles of chickpea seedlings as compared to arsenic stress alone. The arsenic uptake and accumulation in chickpea seedlings were also reduced upon supplementation of Se. The highest reduction of arsenic accumulation by 42 and 56 % in roots, while 47 and 58 % in shoots were recorded by the application of 10 mg/L of Se(0) and Se (VI) under As stress, respectively. Overall, Se(VI) showed much better performance towards the minimization of arsenic-induced phytotoxicity and arsenic accumulation as compared to Se(0). Therefore, this study explored the efficacy of different forms of selenium towards the mitigation of arsenic toxicity in plants.

Synergistic Benefits of Dietary Silymarin and Selenium on Growth, Immune Functions, Antioxidants, and Gut/Liver Health of Thinlip Mullet (Liza ramada) Juveniles

Abstract This study investigates the synergistic impact of silymarin (SI) levels combined with inorganic selenium (sodium selenite: Se) on growth, feed utilization, biochemical parameters, antioxidants, innate immunity, intestinal and liver histology, and gene expression of thinlip mullet (Liza ramada) juveniles. The experimental design involved thinlip mullets initially weighing 3.5±0.13 g, distributed in a completely randomized design with 30 fish per hapa (0.5 × 0.5 × 1 m), and conducted in triplicate over 60 days. Seven experimental diets were employed, including a control (without SI and Se supplementation), a negative control (with only Se supplementation), and four treatments with varying levels of silymarin (250, 450, 650, 850 mg/kg) alongside selenium (0.5 mg/kg diet). The growth performance results highlighted significant enhancements in final body weight, weight gain, and specific growth rate, particularly in the SI 850 mg/kg + Se treatment. Survival rates, feed intake, and feed conversion ratios showed positive trends across the SI-Se supplemented groups. Biochemical profiles of serum exhibited that the control diet induced elevated concentrations of glucose, cholesterol, alanine aminotransferase, aspartate aminotransferase, and urea, while Se or SI supplementation significantly mitigated these levels, with the lowest concentrations observed in the SI-Se supplemented groups. Moreover, SI supplementation increased serum protein content. Antioxidant enzyme activities, represented by superoxide dismutase (SOD), catalase (CAT), and catalase (GPx), demonstrated notable improvements in the SI-Se fortified groups, with significantly elevated GPx activity compared to the Se-supplemented and control groups. Immune system responses, including lysozyme, bactericidal, nitro-blue tetrazolium (NBT%), and serum alternative complement pathway (ACH50) activities, were highest in the SI-Se augmented groups. SI and Se in L. ramada reduce liver pro-inflammatory gene expression (IL-1 β, hepcidin) vs. control group. Histological examinations of the intestine and liver depicted structural enhancements, especially at moderate and high levels of SI with Se supplementation. The results indicate improved intestinal villi morphology and hepatic architecture, supporting the positive influence of dietary treatments on the health of thinlip mullet juveniles. In conclusion, the combined supplementation of SI at 850 mg/kg diet and Se at 0.5 mg/kg diet positively influenced the growth, biochemical profiles, antioxidant status, immune responses, gene expression, and histological integrity of thinlip mullet juveniles, providing valuable insights for optimizing aquafeed formulations.

Optimization of selenium biofortification by liquid fermentation based on 2,4-dichlorophenoxyacetic acid and its effect on nutritional value of Pleurotus ostreatus

Pleurotus ostreatus is one of the most popular edible mushrooms worldwide and has been proposed as a candidate for human selenium (Se) supplementation. The objective of this study is to develop a Se-biofortification method by liquid fermentation and evaluate the effect of 2,4-dichlorophenoxyacetic acid (2,4-D), Na2SeO3 fortification doses and initial pH on P. ostreatus mycelium growth, nutritional value, and mineral accumulation. The optimal growth conditions were identified as 2,4-D 2.00mgL-1, Na2SeO3 30.65mgL-1, and initial pH 5.97 by Box-Behnken design. The optimization resulted in the biomass of 15.75gL-1 and the organic Se content of 594.85mgkg-1, which was 2.50 and 8.03 times higher than the control group, respectively. In parallel, the contents of polysaccharides, proteins, essential amino acids, major functional components, and several minerals in mycelium were increased to varying degrees. Overall, this study will provide an experimental basis for the use of P. ostreatus mycelium as a good carrier for organic Se enrichment by liquid fermentation and technical support for the industrial development of new Se biofortification methods.

The Immunomodulatory Effects of Selenium: A Journey from the Environment to the Human Immune System

Selenium (Se) is an essential nutrient that has gained attention for its impact on the human immune system. The purpose of this review is to explore Se’s immunomodulatory properties and to make up-to-date information available so novel therapeutic applications may emerge. People acquire Se through dietary ingestion, supplementation, or nanoparticle applications. These forms of Se can beneficially modulate the immune system by enhancing antioxidant activity, optimizing the innate immune response, improving the adaptive immune response, and promoting healthy gut microbiota. Because of these many actions, Se supplementation can help prevent and treat pathogenic diseases, autoimmune diseases, and cancers. This review will discuss Se as a key micronutrient with versatile applications that supports disease management due to its beneficial immunomodulatory effects. Further research is warranted to determine safe dosing guidelines to avoid toxicity and refine the application of Se in medical treatments.

PSLBII-17 Supplementation with organic versus inorganic selenium during pregnancy to support ewe and lamb health

Abstract Selenium (Se) is essential for optimal ovine health and production, and sheep raised on Se-deficient soils can be vulnerable to Se deficiencies that can affect immune function. Organic or inorganic forms of Se supplementation can remedy these consequences. While inorganic Se is less costly, organic Se is more bioavailable and may be more efficient in providing Se to ewes and lambs. The objectives of this study were to determine how organic versus inorganic Se supplementation affects ewe Se status, Se transfer from ewes to lambs, and the antibody-mediated immune response and dermal hypersensitivity response (DHR) of ewes and their lambs. Dorset-Rideau ewes (n = 100) were enrolled in a randomized complete block design study. From gestation d (gd) 110 to postpartum d (ppd) 50, ewes were fed either a Se-deficient diet and supplemented with no Se, 0.3 mg inorganic Se, or 0.3 mg or 0.6 mg organic Se. Sera were collected on gd 110, 130, 140, and ppd 10 and 50 to determine ewe Se status. On gd 110 and 120, ewes received an intramuscular injection of 0.5 mg ovalbumin (OVA) antigen, and on gd 130 the DHR to OVA was assessed by measuring change in skinfold thickness 0, 6, 24 and 48 h post intradermal injection. To measure the transfer of Se from ewe to lamb, a subset of lambs was euthanized at ppd 10, and longissimus dorsi muscle samples were collected and analyzed for Se content. On ppd 20 and 30, lambs received an intramuscular injection of 0.5 mg hen egg white lysozyme (HEWL) antigen, and on ppd 40 the DHR to HEWL was assessed using the aforementioned protocol. Analysis of ewe sera showed a positive correlation between organic Se supplementation and greater Se concentrations (P &amp;lt; 0.01). Moreover, statistical analyses of the DHR results using a generalized least squares linear model (RStudio) indicate that Se supplementation increased the immune response compared with the non-supplemented ewes (P &amp;lt; 0.01). However, no significant differences between organic and inorganic Se supplementation were found. In lambs, greater ewe Se supplementation resulted in greater Se muscle content (P &amp;gt; 0.01). and organic Se supplementation to ewes significantly increased lamb Se muscle content compared with inorganic Se supplementation (P &amp;gt; 0.01). Finally, analyses of the lamb DHR showed that maternal organic Se supplementation improved the lamb immune response compared with the control group (P &amp;gt; 0.05). Therefore, organic Se supplementation optimally enhances ewe and lamb Se status and their adaptive immune response compared with the inorganic and control groups. This knowledge will guide optimal ewe Se-supplementation choices during pregnancy and postpartum, thus promoting lamb and ewe health.

Metabolic engineering of Escherichia coli for seleno-methylselenocysteine production

Selenium (Se) is an essential trace element for life. Seleno-methylselenocysteine (SeMCys) can serve as a Se supplement with anticarcinogenic activity and can improve cognitive deficits. We engineered Escherichia coli for microbial production of SeMCys. The genes involved in the synthesis of SeMCys were divided into three modules–the selenocysteine (SeCys) synthesis, methyl donor synthesis and SMT modules–and expressed in plasmids with different copy numbers. The higher copy number of the SeCys synthesis module facilitated SeMCys production. The major routes for SeCys degradation were then modified. Deletion of the cysteine desulfurase gene csdA or sufS improved SeMCys production the most, and the strain that knocked out both genes doubled SeMCys production. The addition of serine in the mid-logarithmic growth phase significantly improved SeMCys synthesis. When the serine synthetic pathway was enhanced, SeMCys production increased by 12.5 %. Fed-batch culture for sodium selenite supplementation in the early stationary phase improved SeMCys production to 3.715 mg/L. This is the first report of the metabolic engineering of E. coli for the production of SeMCys and provide information on Se metabolism.

Selenium promotes broiler myoblast proliferation through the ROS/PTEN/PI3K/AKT signaling axis

Selenium (Se), an indispensable trace element in broiler chickens, is closely associated with the growth and development of skeletal muscles. However, the role of Se in the proliferation of broiler myoblasts and its specific biological mechanisms have not been elucidated. In the present study, an in vitro growth model of broiler pectoral myoblasts cultured with Se (Na2SeO3) for 24 h was established. Using light microscopy, Cell Counting Kit-8 (CCK-8) assay, and flow cytometry, we found that compared to the control (Con) group, Se supplemental level obviously promoted myoblast proliferation and prevented cell cycle arrest from the G1 phase to the S + G2 phase. Through intracellular reactive oxygen species (ROS) generation detection, western blotting, and quantitative reverse transcription-polymerase chain reaction (qRT-PCR), the study showed that the reduced ROS production caused by Se supplementation significantly decreased PTEN expression and activated the PI3K/AKT signaling pathway in myoblasts, thereby promoting the P53/P21/CyclinD1-regulated cell cycle progression, as well as the expression of proliferation-related myogenic regulatory factors (MRF). Our findings support the potential of Se to maintain the proliferative capacity of chicken myoblasts and emphasize the importance of Se intake in regulating skeletal muscle growth and development in poultry.

Impacts of Selenium Supplementation on Soil Mercury Speciation, Soil Properties and Mercury-Resistant Microorganisms and Resistant Genes

Soil mercury (Hg) contamination is a serious threat to local ecology and public health. Exogenous selenium (Se) supplementation can effectively reduce the toxicity of Hg. However, the mechanisms affecting the changes in soil Hg speciation, soil properties and the microbial Hg-resistant system during the Se–Hg interaction after exogenous Se supplementation are not clear. Therefore, in this study, soil culture experiments were conducted to analyze the effects of different Se additions on the transformation of Hg speciation, soil properties and Hg-resistant microorganisms and resistant genes (mer operon). The results indicated that Se supplementation facilitated the transformation of soil Hg from bioavailable (exchangeable and carbonate-bound) to stable forms (organic material-bound and residual), significantly reducing Hg bioavailability. Se supplementation notably decreased the electrical conductivity of Hg-contaminated soil, but had no significant effect on the soil pH, organic matter content, cation exchange capacity or alkaline phosphatase and catalase activities. The maximum activity levels of soil sucrase and urease were observed when 1 mg kg−1 Se was added. Se significantly inhibited soil peroxidase and ascorbate oxidase activities, thereby alleviating the oxidative stress in the soil system caused by Hg. Additionally, Se significantly activated the Hg-resistant system in soil microorganisms by either decreasing or increasing the regulatory genes merD and merR, and it significantly upregulated the cytoplasmic protein gene merP and the membrane protein genes merC, merF and merT. This further increased the abundance of the organomercury lyase gene merB and the mercuric reductase gene merA, promoting the conversion of Hg species to Hg⁰. Furthermore, the abundance of mer operon-containing microorganisms, such as Thiobacillus ferrooxidants, Pseudomonas, Streptomyces and Cryptococcus, significantly increased with Se addition, explaining the role of soil microorganisms in mitigating soil Hg stress via Se supplementation.

Supplementation of juvenile Siberian sturgeon (Acipenser baerii) diet with different levels of selenium: Growth performance, digestive enzyme activities, and intestinal histomorphology

This study aimed to investigate the impact of dietary Selenium (Se) on the growth performance, body composition, digestive enzymes, and intestinal histomorphology of Siberian sturgeon, Acipenser baerii. Fish (10.0±0.5 g) were randomly assigned to fifteen 1000-L tanks (30 fish per replicate) in a flow-through system and fed three times a day (08.00, 13.00, 18.00) with isonitrogenous (54.21 % crude protein) and isolipidic (15.63 % crude lipid) diets supplemented with selenomethionine at levels of 0, 0.2, 0.4, 0.8, and 1.6 mg kg−1 providing the analyzed Se of 0.10, 0.29, 0.49, 0.88, and 1.70 mg kg−1, respectively. Each three tanks were allocated to each treatment. After the eight-week feeding trial, weight gain ratio, specific growth rate, and survival rate of fish significantly increased with increasing dietary Se supplementation (p<0.05) and reached to the highest values of 156.00±0.68 %, 1.68±0.07 % d−1, and 98.33±1.66 %, respectively, while the feed conversion ratio declined to the lowest value of 1.79±0.10. Protein and lipid content increased with Se levels to the highest values of 20.15±0.11 % and 8.23±0.05%, respectively (p<0.05). Activity of all digestive enzymes including trypsin, chymotrypsin, α-amylase, lipase, and alkaline phosphatase significantly enhanced with increasing dietary Se levels (p<0.05). Increasing trends in villus height, villus width, muscle thickness, and crypt depth were found by increasing dietary Se supplementation with the highest values of 502.33±31.25, 134.39±13.12, 194.18±11.37, and 67.29±0.12 µm, respectively, in fish fed diet supplemented with 1.70 mg kg−1 Se (p<0.05). Findings of the present study illustrated the beneficial effects of dietary Se on performance, digestive enzymes, and intestinal histomorphology of Siberian sturgeon. According to the polynomial regression analysis, the optimum dietary requirement of Siberian sturgeon was in the range of 1.47–1.69 g kg−1.

Unravelling the bridge of polyphenol composition and mineralomics in Se biofortified edible Allium species

Selenium is an essential element for the well-being of humans and animals. Micronutrient deficiencies affect over half of the global population. Biofortification of crops with selenium represents an economically sustainable solution to combat this problem. In this study, seven Allium species underwent Se biofortification, via Se soil enrichment with selenate in pots, at three distinct concentration levels and were used to explore the relationship between Se plant internalization, polyphenol composition, and mineral content. Allium species were chosen because they are recognized as secondary accumulators of Se. Plant morphology, as well as the presence of fifteen phenolic acids and flavonoids, were analysed using a UHPLC-DAD system. Mineral content was determined using both ICP-OES and FAES. Se levels were quantified using a validated method based on HG-HR-CS-QT-AAS. Even at the lowest biofortification level, Allium species demonstrated potential as sources of dietary Se, offering viable alternatives to Se supplements, without negatively impacting the main mineral content. Higher biofortification levels led to reduced levels of flavonoids and phenolic acids, accompanied by potential decreases in biomass for certain species. The study highlighted how Se concentration affects key polyphenols like quercetin, gallic acid, and luteolin, although the response varied among species.

Comparative study of dietary selenium sources on gilthead seabream (Sparus aurata): Growth, nutrient utilization, stress response and final product quality

Selenium (Se) is a crucial trace mineral in human nutrition, known for its various health benefits, including the enhancement of antioxidant defenses. Enrichment of fish fillets with Se is seen as an interesting strategy to reduce the risk of Se deficiency in human diets. While inorganic sources have been traditionally used to supplement Se in fish diets, organic Se forms have demonstrated superior bioavailability and efficacy in managing oxidative stress and tissue retention rates compared to their inorganic counterparts.The main objective of this study was to assess the performance, stress resistance, and product quality of gilthead seabream (Sparus aurata) in response to diets supplemented with 0.2 mg kg−1 of Na2SeO3 (CTRL), Zn-L-SeMet (AVSe) or OH-Se-Met (ORGSe), complying therefore with the European Food Safety Agency (EFSA) maximum allowed supplementation of organic Se (0.2 mg kg−1). Diets were formulated to be similar in their protein (48% DM) and lipid content (17% DM), and hand-fed to apparent satiety to quadruplicate groups of 20 fish (initial body weight ∼ 75 g) gilthead seabream juveniles for 137 days. Fish were kept in a recirculating saltwater system (salinity 35‰, 22 ± 1 °C) until they reached commercial size (>250 g). At the end of the growth trial, all fish were individually weighed and measured, with 4 fish per tank sampled for whole-body composition analysis. Fillet yield, muscle lipid and mineral composition, and hepatic oxidative stress indicators were assessed (n = 12). Lipid peroxidation, muscle pH, water-holding capacity (WHC), color, and texture were evaluated on days 7 and 14 (n = 8), while sensory analysis was conducted on 20 fish. Additionally, 12 fish per treatment were subjected to overcrowding (100 kg m−3) for 5 min and air exposure for 1 min. After a 1-h recovery period, plasma and liver samples were collected from these fish, and results were compared to those of the non-stress group. All diets yielded equivalent growth performance, ensuring low feed conversion ratio. Fish fed the AVSe diet exhibited higher whole-body protein content compared to those fed the CTRL diet. Regarding mineral utilization, increased Se retention and gain in fish fed AVSe and ORGSe diets led to higher Se content in these fish compared to the CTRL. Additionally, the AVSe diet has also resulted in significantly increased Se deposition in the muscle compared to the other tested Se sources, contributing with 34% of the Se Daily Recommended Intake (DRI). The assessed flesh quality parameters and overall consumer acceptance did not reveal significant differences among the groups. Exposure to an acute stress was found to decrease the activities of Glutathione reductase and glutathione peroxidase, which in turn has increased the level of oxidized glutathione, particularly in the AVSe group. Compared to OH-Se-Met and Na2SeO3, Zn-L-SeMet was more effective in promoting response to stress and nutritional value of gilthead seabream as an important source of protein and Se in human diet.

Effects of in ovo supplementation of selenium (Se) and zinc (zn) on hatchability and production performance of broiler chickens.

The current research was conducted to assess the effect of in ovo feeding (IOF) of selenium (Se) and zinc (Zn) on hatchability, production performance, liver, intestinal morphology, antioxidant levels and expression levels of immune-related genes in broiler chickens. A total of 400 fertilized eggs were equally divided into four groups: control (non-injected), sham (in ovo injection of 0.75% NaCl), Se (@ 1.5µg/egg in ovo injection) and Zn (500µg/egg in ovo injection) groups respectively. On the seventeenth day of incubation, treatment solutions were administered into amniotic fluid of fertilized eggs. The results revealed that Se and Zn supplementation significantly (P < 0.05) enhanced hatchability, post-hatch growth, organ development, and liver antioxidant capability. Histopathological examination revealed a typical hepatocyte morphology, well-arranged cells, and a significant (P < 0.05) decrease in apoptosis in both selenium and zinc groups. Additionally, selenium and zinc produced auspicious effects on intestinal epithelium and villi surface area. Interestingly, our results revealed that IOF of Se and Zn modulated the expression of immune-related genes in comparison to the control and sham groups. Conclusively, IOF of Se and Zn augmented health and productivity by enhancing the cellular immunity in the broiler chickens, thus IOF can be utilized as an effective strategy to promote health and immunity in broiler chickens.

Research Progress on the Physiological Mechanism by Which Selenium Alleviates Heavy Metal Stress in Plants: A Review

Human activities, such as mining, industrialization, industrial waste emissions, and agricultural practices, have caused heavy metals to become widespread and excessively accumulated in soil. The high concentrations of heavy metals in soil can be toxic to plants, severely affecting crop yield and quality. Moreover, these heavy metals can also enter the food chain, affecting animals and humans and leading to various serious illnesses. Selenium (Se) is not only an essential element for animals and humans but is also beneficial for plants, as it promotes their ability to respond actively to biotic and abiotic stresses. The global issue of Se deficiency in diets has made plants the primary source for human Se supplementation. This paper comprehensively reviews the effects of heavy metal stress on plant growth and development, physiological responses of plants to such stress, and the intracellular transport processes of heavy metals within plants. It particularly focuses on the mechanisms by which Se alleviates heavy metal stress in plants. Additionally, the study delves into how Se significantly enhances plant tolerance mechanisms against typical heavy metals, such as cadmium (Cd), lead (Pb), and mercury (Hg). This integrative research not only expands the boundaries of research in the field of plant heavy metal stress and Se application but also provides new perspectives and solutions for understanding and addressing complex environmental heavy metal pollution issues. By integrating these aspects, this paper not only fills existing gaps in the literature but also offers comprehensive scientific basis and strategic recommendations for environmental protection and sustainable agriculture development.

Foliar application of sodium selenite affects the growth, antioxidant system, and fruit quality of strawberry.

Selenium (Se) plays a vital role in various physiological processes in plants and is regarded as an essential micronutrient for human health as well. In this study, sodium selenite solution at 10, 40, 70, and 100 mg·L-1 concentrations was foliar sprayed, and the strawberry plant growth, antioxidant system, and fruit quality with an emphasis on sugar and acid content were assessed. The results showed that 10 mg·L-1 of sodium selenite treatment promoted plant growth, while all the treated concentrations could enhance photosynthesis, the antioxidant system in leaves, the content of Se, and ascorbic acid in fruits. More importantly, 40 mg·L-1 sodium selenite treatment significantly increased fruit weight, total soluble solid, total phenolic content, and anthocyanins, as well as improved the shape index. Furthermore, it decreased the total flavonoid and proanthocyanidin content. Particularly, sodium selenite treatment at 40 and 70 mg·L-1 largely increased the ratio of soluble sugars to titratable acid. The changes of predominant sugars and organic acids during fruit development were further investigated. The sucrose, fructose, and glucose content was upregulated by sodium selenite treatment through upregulating the activities of sucrose phosphate synthase (SPS) and acid invertase, as well as the FaSPS expression. In addition, sodium selenite treatment inhibited the activity of citrate synthase and phosphoenolpyruvate carboxylase, rather than modulating their transcript levels to reduce the citric acid content. This work presented a potentially efficient approach to enhance plant growth and fruit quality and supplement Se in strawberry, providing insights into the mechanism of regulating sugar and acid metabolism by Se.

Mitigating effects of selenium and zinc on oxidative stress and biochemical and histopathological changes in lung during prenatal and lactational exposure rats to barium chloride.

Selenium (Se) and zinc (Zn) are essential trace elements with antioxidant properties, and their supplementation has been shown to be protective against the toxicity of various environmental and dietary substances. The aim of this study was to investigate the potential protective effect of selenium and zinc as adjuvants against barium (Ba) toxicity in lactating rats and their offspring. The pregnant rats were divided into six groups: the first as control; group 2 received barium (67ppm) in the drinking water; group 3 had combined Ba + Se (0.5mg/kg) in the diet; group 4 received Zn (50mg/kg bw) by gavage together with Ba; groups 5 and 6, positive controls, were treated with selenium (0.5mg/kg) and zinc (50mg/kg bw), respectively. MDA, H2O2, AOPP, CAT, GPx, and SOD levels were measured and lung histopathology was performed. Our results showed that barium administration caused lung damage as evidenced by an increase in MDA, H2O2, and AOPP levels and a decrease in the activities of CAT, GPx, and SOD in mothers and their offspring. A decrease in lung GSH, NPSH, and MT levels was also observed. Supplementation of Ba-treated rats with Se and/or Zn significantly improved the pulmonary antioxidant status of mothers and their offspring. Histopathological examinations were also consistent with the results of biochemical parameters, suggesting the beneficial role of Se and Zn supplementation, as evidenced by less accumulation of collagen fibers as studied by hematoxylin and eosin (H&E) and Masson's trichrome staining. In conclusion, we demonstrate the adverse effects of maternal barium exposure during pregnancy and on neonatal lung health and the protective effects of selenium and zinc in preventing the adverse effects of barium exposure.