Forms Of Se Research Articles

Selenium foliar application contributes to decrease ratio of water-soluble fluoride and improve physio-biochemical components in tea leaves

The tea plant accumulates elevated levels of fluoride (F) from environmental sources. Drinking tea containing high F levels poses a potential threat to human health. Selenium (Se) was applied by foliar spray to investigate its effects on F accumulation and physiology in tea plant. Foliar application of different forms of Se, i.e., Na2SeO3, Kappa-selenocarrageenan, Selenomethionine and Nanoselenium, reduced F content in tea leaves by 10.17 %−44.28 %, 16.12 %−35.41 %, 22.19 %−45.99 % and 22.24 %−43.82 %, respectively. Foliar spraying Se could increase F accumulation in pectin through increasing pectin content and pectin demethylesterification to bind more F in the cell wall, which decreased the proportion of water-soluble fluoride in tea leaves. Application of Se significantly decreased the contents of chromium (39.6 %−72.0 %), cadmium (48.3 %−84.4 %), lead (2.2 %−44.4 %) and copper (14.1 %−44.6 %) in tea leaves. Foliar spraying various forms of Se dramatically increased the Se content and was efficiently transformed into organic Se accounting for more than 80 % in tea leaves. All Se compounds increased peroxidase activity by 3.3 %−35.5 % and catalase activity by 2.6 %−99.4 %, reduced malondialdehyde content by 5.6 %−37.1 %, and increased the contents of chlorophyll by 0.65 %−31.8 %, carotenoids by 0.24 %−27.1 %, total catechins by 1.6 %−21.0 %, EGCG by 4.4 %−17.6 % and caffeine by 9.1 %−28.6 %. These results indicated that Se application could be served as a potential efficient and safe strategy diminishing the concentration of F in tea leaves.

Meta-analysis of the effects of dietary sources of selenium on lactational performance and oxidative status of dairy cows

Selenium is an essential trace element to maintain normal physiological and immunological systems. The role of various types and forms of Se on the productive performance and antioxidant status of dairy cows is overwhelming in the existing empirical evidence and, therefore, needs to be quantitatively summarized. This meta-analysis evaluated the effects of different types and forms of Se intake on the productive and oxidative status of various physiological stages of dairy cows. A database was built from 29 peer-reviewed publications that reported lactation performance, Se concentrations in the blood or milk, or antioxidant parameters of dairy cows. A total of 139 observations were included in the analysis according to mixed model univariate and multivariate regression analyses by evaluating the Se levels (%), intake (mg/d), Se forms (organic vs inorganic), Se types (Se-selenite, Se-yeast, Se-methionine) and other categorical predictors in the models. Then, the models were evaluated and cross-validated to select the best-fitted models on some important parameters. Se intake, in any form and type, had no relationship with milk yield but was positively associated with fat-corrected milk (FCM) yield due to a trend of linear increase in milk fat yield (g/d). A significant interaction of Se intake × lactation phase was observed. Daily Se intake positively affected the dry matter intake (DMI) of periparturient cows but did not affect the DMI of lactation cows. Increasing Se intake resulted in a linear increase of DMI and moderately increased glutathione peroxidase (GSH-Px) during the periparturient period but had no significant effect during early and mid-lactation of dairy cows. The interaction model of Se intake × Se forms was the best predictor to evaluate Se concentration in blood and milk. The organic Se had a higher transfer rate from diets to blood without a statistical difference between Se-yeast and Se-methionine. In milk, intake of Se-methionine demonstrated a strong linear increase in Se concentration and had a 47% higher slope of transfer rate than Se-yeast (2.47 µg/kg and R2 = 0.91 vs 1.68 µg/kg and R2 = 0.48, respectively). The amount of daily Se intake also curvilinearly affected superoxide dismutase activity and malondialdehyde concentration. Altogether, the predicted models and results of the present meta-analysis provide empirical evidence that organic Se, especially Se-methionine, had a higher transfer rate from diets into the milk than organic Se-yeast. Organic Se might also improve milk protein and fat-corrected milk in lactating cows and antioxidant status in the periparturient period of dairy cows.

Water extract of Fagopyrum dibotrys (D. Don) Hara straw increases selenium accumulation in peach seedlings under selenium-contaminated soil

To promote the selenium (Se) uptakes in fruit trees under Se-contaminated soil, the effects of water extract of Fagopyrum dibotrys (D. Don) Hara straw on the Se accumulation in peach seedlings under selenium-contaminated soil were studied. The results showed that the root biomass, chlorophyll content, activities of antioxidant enzymes, and soluble protein content of peach seedlings were increased by the F. dibotrys straw extract. The different forms of Se (total Se, inorganic Se, and organic Se) were also increased in peach seedlings following treatment with the F. dibotrys straw extract. The highest total shoot Se content was treated by the 300-fold dilution of F. dibotrys straw, which was 30.87% higher than the control. The F. dibotrys straw extract also increased the activities of adenosine triphosphate sulfurase (ATPS), and adenosine 5'-phosphosulfate reductase (APR) in peach seedlings, but decreased the activity of serine acetyltransferase (SAT). Additionally, correlation and grey relational analyses revealed that chlorophyll a content, APR activity, and root biomass were closely associated with the total shoot Se content. Overall, this study shows that the water extract of F. dibotrys straw can promote Se uptake in peach seedlings, and 300-fold dilution is the most suitable concentration.

Selenium bioaccessibility in rice grains biofortified via soil or foliar application of inorganic Se

Selenium (Se) is a micronutrient for humans, and its deficiency is related to various diseases. Recent studies have proposed strategies to increase Se intake, especially using selenium biofortification in staple foods. However, few investigations shed light on the chemical species and the bioavailability of Se in cereal grains, including rice, one of the most important staple foods worldwide. This study aimed to determine the bioaccessible fractions of Se in rice grains biofortified with inorganic Se species using an in vitro sequential extraction method to simulate human digestion. Samples and extracts were submitted to microwave-assisted acid digestion, and total/bioaccessible Se levels were determined by DRC-ICP-MS. Accurate Se quantification was achieved using matrix-matching calibration. Rice biofortification via foliar application increased Se levels in the bioaccessible fraction more effectively than soil applications. Bioaccessible Se represented, on average, 61 ± 5 % of the total levels. Of the total Se content in rice, 44 ± 4 % was extracted in the gastric step, which is where most protein-bound bioaccessible selenium is degraded. Biofortification with inorganic forms of Se effectively increases the bioaccessible content of this element in food. Still, the amount to be applied must be corrected based on the bioaccessible fraction of the nutrient in rice grains.

Transcriptome analysis reveals the molecular mechanism of different forms of selenium in reducing cadmium uptake and accumulation in wheat seedlings

Selenium (Se) can counteract cadmium (Cd) toxicity in wheat, but the molecular mechanism of different Se forms reducing Cd uptake and accumulation in wheat seedlings remain unclear. Here, a hydroponic experiment was conducted to investigate the effects of three Se forms (selenite (Se(IV)), selenate (Se(VI)) and seleno−L−methionine (SeMet)) on Cd2+ influx, Cd subcellular distribution, and Cd accumulation in wheat seedlings, and the underlying molecular mechanisms were investigated through transcriptome analysis. Consequently, Se(IV) and Se(VI) addition significantly reduced root Cd concentration by 74.3% and 80.8%, respectively, and all Se treatments significantly decreased shoot Cd concentration by approximately 34.2%–74.9%, with Se(IV) addition having the most pronounced reducing effect. Transcriptome analysis showed the reduction of Cd accumulation after Se(IV) addition was mainly due to the downregulation of Cd uptake genes. The inhibition of Cd accumulation after Se(VI) addition was not only associated with the downregulation of Cd uptake genes, but also related to the sequestration of Cd in vacuole. For SeMet addition, the reduction of Cd accumulation was mainly related to the sequestration of Cd in vacuole as GSH−Cd. The above findings provide novel insights to understand the effects of different forms of Se on Cd uptake and accumulation and tolerance in wheat.

Selenate triggers diverse oxidative responses in Astragalus species with diverse selenium tolerance and hyperaccumulation capacity

Selenium (Se) hyperaccumulators are capable of uptake and tolerate high Se dosages. Excess Se-induced oxidative responses were compared in Astragalus bisulcatus and Astragalus cicer. Plants were grown on media supplemented with 0, 25 or 75 μM selenate for 14 days. Both A. bisulcatus and A. cicer accumulated >2000 μg/g dry weight Se to the shoot but the translocation factors of A. cicer were below 1 suggesting its non hyperaccumulator nature. A. cicer showed Se sensitivity indicated by reduced seedling fresh weight, root growth and root apical meristem viability, altered element homeostasis in the presence of Se. In Se-exposed A. bisulcatus, less toxic organic Se forms (mainly MetSeCys, γ-Glu-MetSeCys, and a selenosugar) dominated, while these were absent from A. cicer suggesting that the majority of the accumulated Se may be present as inorganic forms. The glutathione-dependent processes were more affected, while ascorbate levels were not notably influenced by Se in either species. Exogenous Se triggered more intense accumulation of malondialdehyde in the sensitive A. cicer compared with the tolerant A. bisulcatus. The extent of protein carbonylation in the roots of the 75 μM Se-exposed A. cicer exceeded that of A. bisulcatus indicating a correlation between selenate sensitivity and the degree of protein carbonylation. Overall, our results reveal connection between oxidative processes and Se sensitivity/tolerance/hyperaccumulation and contribute to the understanding of the molecular responses to excess Se.

Development of polymer films and biological matrices standards for selenium, mercury and endogenous elements quantitative LA-ICP MS imaging in entire rainbow trout fry

The quantitative imaging of trace elements in biological samples can bring information on their assimilation pathways and help understanding their toxicity or essentiality. This study presents the development of two quantitative LA-ICP MS methodologies and their comparison for Se, Hg, Cu, Zn and Mo imaging in rainbow trout. The first method is based on spiked polymer films (dextran) allowing internal standardization with Ge and Te. The second method relies on the matrix-matched standards (MMS) methodology, with homogenized and spiked trout muscle and calf liver. For Se, Cu, Zn and Mo, linear regressions with correlation coefficient above 0.994 were obtained by LA-ICP MS analysis for both methods. For Hg, only MMS calibration provided linear regression as polymer films exhibited Hg unstable signals during LA-ICP MS analysis. Element concentrations spiked in muscle and liver MMS were also confirmed by ICP MS and used to validate the polymer films method as values obtained for Se, Hg, Mo and Cu were in good agreement. While LODs of polymer film method were in the range of 0.06–0.6 µg.g−1 for Cu, Se, Mo, and 5 µg.g−1 for Zn, values were higher for MMS method (from 0.06 (Mo) to 2.2 (Cu) µg.g−1, and 30 of µg.g−1 for Zn). Particular attention has been paid to sample embedding and water was found to minimize internal standard response bias. Both methods were then applied to the quantitative mapping of these five elements in rainbow trout fry supplemented or not with organic forms of Se and Hg through parental and direct feeding. Calibrations were analysed before and after sample imaging evidencing a lower bias between the two quantifications with polymer films calibration than with MMS calibration. For the first time, elements concentrations were determined at 60 × 60 µm spatial resolution in specific tissues or organs of entire fry. Depending on the element, polymer films quantification was in agreement with trout muscle (Cu, Se) or with calf liver MMS quantification (Zn).

Effects of High Doses of Selenate, Selenite and Nano-Selenium on Biometrical Characteristics, Yield and Biofortification Levels of Vicia faba L. Cultivars.

Faba bean (Vicia faba L.) has spread worldwide as an excellent source of proteins. To evaluate the efficiency of Se biofortification, four cultivars of V. faba (Belorussian, Russian Black, Hangdown Grünkernig, and Dreifach Weiβe) were foliar treated with 1.27 mM solutions of nano-Se, sodium selenate, and sodium selenite. Yield, protein, and Se contents were greatly affected by genetic factors and chemical form of Se. Selenium biofortification levels were negatively correlated with Se concentration in control plants and increased according to the following sequence: nano-Se < sodium selenite < sodium selenate. Contrary to selenate and selenite, nano-Se showed a growth-stimulating effect, improving yield, seed weight, and pod number. Pod thickness decreased significantly as a result of nano-Se supply and increased by 1.5-2.3 times under selenate and selenite supply. The highest Se concentrations were recorded in the seeds of Se-fortified cv. Belorussian and the lowest one in those of Se-treated Hangdown Grünkernig. Protein accumulation was varietal dependent and decreased upon 1.27 mM selenate and selenite treatment in the cvs. Hangdown Grünkernig and Dreifach Weiβe. The results indicate the high prospects of nano-Se supply for the production of faba bean seeds with high levels of Se.

Comparison of Selenium Accumulation in Edible Parts of Wheat and Broad Bean

The concentration of selenium (Se) in agricultural products primarily depends on the concentration of Se in soil and the ability of plants to accumulate Se. Selenium deficiency not only leads to decreased body resistance, but also increases the risk of cancer. The form and concentration of bioavailable Se is important for diet. The present study was carried out via field experiment with wheat and broad beans in soil of different Se concentrations (0, 1.12, and 11.2 kg·ha−1), which was determined based on the national standard and the team’s previous experience. Results indicated that the concentration of Se in the edible organs of wheat was higher than in broad bean, while the enriched Se concentration in the root of broad bean was more than twice and three times higher than that of wheat at medium and high levels of Se, respectively. Selenomethionine, which accounted for over half of the total Se speciations, was the dominant species in the edible parts of the two crops, followed by Selenocystine and methylselenocysteine. Through the analysis of the rhizosphere soil, it was found that Fe-Mn oxide-bound Se exceeded 80% of the total Se. Additionally, there was a significant linear correlation between the Se content in the edible parts of the two crops and the Se content in the soil. Findings suggested that wheat was more favorable than broad beans as Se supplement crops in a Se-supplied field.

Effects of nitrogen and selenium treatments on the texture parameters of ‘Qingcui’ plum fruit

‘Qingcui’ plum fruit becomes soft at harvesting. In this study, we assessed the effect of the following different treatments on various fruit texture parameters: three concentrations of nitrogen (NH4NO3 0%, 0.5% and 1%) and three forms of selenium (selenomethylcysteine [C5H9NO2SSe/SeMeCys], sodium selenate [Na2SeO4] and sele-nomethionine [SeMet]). The fruit texture parameters evaluated were fracture, hardness, cohesiveness, springiness, gumminess, chewiness and initial modulus under 4oC. Results showed that the optimal N concentration was 1% and the optimal Se form was SeMeCys. Fruits treated with SeMeCys had similar fruit texture parameters as those of the group under cysteine treatment. We then sprayed the fruit with approximately 2 mL/fruit of the following treatments: five different combinations ratios of Se (SeMeCys; 10 mg/L) and N (NH4NO3; 1%) (2:18; 4:16; 10:10; 16:4; 18:2), after which the fruit was stored at 4oC for 13 days. The parameters of fruit texture, fruit color, and other fruit qualities were measured. Linear correlations were observed between parameters, and main sensory qualities were analyzed. We observed that a combination of Se and N in a ratio of 18:2 produced the best results in terms of fracture, first hardness and second hardness, preventing the softening of the fruit. The parameters of soluble protein, titratable acid and soluble solids had significant linear relationships with three fixture parameters. The fruit color parameters of a* (greenness) and b* (yellowness) also had significant linear correlations with fracture and first hardness. These findings may offer a promising strategy to prolong fruit storage and maintain fruit crispness and hardness.

Gene expression profiling indicates a shift in ammonia assimilation capacity along the hepatic acinus induced by different forms of selenium in vitamin–mineral mixes fed to beef steers grazing on toxic endophyte-infected tall fescue

Recently, we demonstrated that supplementing (with 3 mg Se per day) the diets of growing beef steers grazing on Se-deficient toxic endophyte-infected tall fescue-based forage with either organic Se (OSe, SEL-PLEX) or a 1:1 blend (MIX) of OSe and inorganic Se (ISe, sodium selenite) in vitamin–mineral mixes, rather than inorganic forms of Se, ameliorated several classic serum symptoms of fescue toxicosis. Importantly, higher levels of hepatic glutamine synthetase activity were observed in MIX and OSe steers. Accordingly, transcriptome level and targeted mRNA expression analyses were conducted on the same liver tissue to determine if Se treatments affected other hepatic metabolic pathways, especially those that are responsible for supplying substrates of glutamine synthetase. The effect of ISe, OSe, and MIX treatments (n = 8/treatment) on the relative abundances of mRNA [determined using microarray and real-time reverse-transcription PCR (RT-PCR)] and protein (determined using Western blotting) in liver tissue was assessed by ANOVA. Fisher’s protected LSD procedure was used to separate treatment means, with significance being declared at p ≤ 0.05. Microarray analysis identified (p&amp;lt; 0.01, false discovery rate of&amp;lt; 33%) 573 annotated differentially expressed gene (DEG) transcripts. Canonical pathway analysis identified the DEGs that are central to glutamine and glutamate biosynthesis/degradation and proline biosynthesis. Targeted RT-PCR analyses found that MIX and OSe steers had lower periportal ammonia-assimilation and urea-synthesizing capacities (lower glutaminase 2, key ornithine cycle enzymes, and mitochondrial ornithine/citrulline exchanger mRNA) than ISe steers. In addition, MIX and OSe steers had a higher capacity for pericentral ammonia assimilation (higher glutamine synthetase activity) and a higher capacity for the production of glutamate in pericentral hepatocytes from α-ketoglutarate (higher levels of glutamine dehydrogenase, and decreased levels of arginase 2 and ornithine aminotransferase and mRNA). The form of supplemental Se also affected steers’ capacity for hepatic proline metabolism, with OSe steers having a higher capacity for proline synthesis and MIX steers having a higher capacity for pyroline-5-carboxylate synthesis. In conclusion, supplementing the diets of growing beef steers grazing on toxic endophyte-infected tall fescue with MIX and OSe in vitamin–mineral mixes, rather than with inorganic forms of Se, shifts hepatic ammonia assimilation from periportal urea production to pericentral glutamine production, thus potentially increasing whole-animal N efficiency by increasing the supply of hepatic-synthesized glutamine.

Onion Biofortification Using Selenium Bionanofertilizer and its Bulk Source under Sandy Soil Conditions

Human health depends on the daily supply of fresh vegetables and fruits, which contain the essential, nutrients, vitamins and other bioactive compounds. Due to malnutrition in several places all over the world, the biofortification approach is a crucial solution to overcome this global problem. In the current study, the biological nanofertilizer of selenium (nano-Se) was tested on onion crop comparing with its bulk source under the sandy soil conditions. the applied doses of nano-Se were 10, 20, 30 and 40 mg L−1 in both nano and mineral form of Se. The main investigated parameters of onion were the vegetative growth parameters and the nutritional status in leaves and bulbs. The obtained results have a significant difference between mineral and nano-Se doses for studied measurements. In general, all studied parameters increased in their values with increasing the applied doses from both Se sources up to 30 or 40 mg L−1 compared to the control, depending on the selected parameter. This increase reached to more than 60% (for applied nano-Se on bulb dry weight), or more than 55% for the same parameter after applying mineral Se source. Applying nano Se was achieved higher values in some studied parameters of onion, whereas the mineral form of Se was domain for others. This study confirmed that both Se forms can be applied for biofortification of onion because the Se content in bulb located in the accepted level of Se in crop with priority to nano-Se, which accumulate in leaves and bulb in a lower concentration compared to mineral form. This work opened more question about the nano-biofortification and the possibility to apply for more studied crops with focus on the suitable added dose to be safe for successful biofortification program.

Mercury and selenium co-ingestion assessment via rice consumption using an in-vitro method: Bioaccessibility and interactions

Mercury (Hg) was reported to accumulate in rice grains, and, together with the selenium (Se) was found in rice, the co-exposure of Hg-Se via rice consumption may present significant health effects to human. This research collected rice samples containing high Hg:high Se and high Se:low Hg concentrations from high Hg and high Se background areas. The physiologically based extraction test (PBET) in vitro digestion model was utilized to obtain bioaccessibility data from samples. The results showed relatively low bioaccessible for Hg (<60%) and Se (<25%) in both rice sample groups, and no statistically significant antagonism was identified. However, the correlations of Hg and Se bioaccessibility showed an inverse pattern for the two sample groups. A negative correlation was detected in the high Se background rice group and a positive correlation in the high Hg background group, suggesting various micro forms of Hg and Se in rice from different planting locations. In addition, when the benefit-risk value (BRV) was calculated, some “fake” positive results showed while Hg and Se concentrations were directly used, which indicated that bioaccessibility should not be neglected in benefit-risk assessment.

Molecular Mechanism of Exogenous Selenium Affecting the Nutritional Quality, Species and Content of Organic Selenium in Mustard

It is an essential method for healthy Selenium (Se) supplementation to convert exogenous Se into organic Se via crops. Brassica juncea (L.) Czern (leaf mustard) was employed as plant material in this investigation and was treated with sodium selenite (Na2SeO3). Its physiological indicators, nutritional quality, antioxidant enzyme activity, total Se content, and Se morphology were all evaluated. The absorption, transportation, and transformation mechanisms of Se in mustard were studied using transcriptome data. The results revealed that low concentration of Se treatment promoted the growth of mustard, while high concentration Se treatment inhibited it. The concentration of 10 mg/L Na2SeO3 treatment had the best growth parameters for mustard. Compared to the control group, the content of vitamin C (Vc) and anthocyanins in the treatment group increased to varying degrees, while the content of flavonoids, total phenols, soluble sugar, and soluble protein increased first and then decreased. Five Se forms, Se (IV), Se (VI), selenocystine(SeCys2), selenomethionine (SeMet), and methylselenocysteine (MeSeCys), were detected in the Na2SeO3 treatment group, with organic Se accounting for over 95%. Na2SeO3 treatment can significantly reduce the accumulation of ROS in mustard plants and enhance their stress resistance. Transcriptome data and metabolite association analysis showed that PHO1-H8 promoted the absorption of Na2SeO3 by mustard roots, while SULTR3;3 and SULTR4;1 promoted the transport of Se from roots to the aboveground portion and chloroplasts. Se in mustard was transformed into SeMet, SeCys, MeSeCys, and selenoprotein through the action of genes such as APS, APR, and SEP1, and stored in plant leaves.

Time-Resolved Examination of Fungal Selenium Redox Transformations.

Selenium (Se) is both a micronutrient required for most life and an element of environmental concern due to its toxicity at high concentrations, and both bioavailability and toxicity are largely influenced by the Se oxidation state. Environmentally relevant fungi have been shown to aerobically reduce Se(IV) and Se(VI), the generally more toxic and bioavailable Se forms. The goal of this study was to shed light on fungal Se(IV) reduction pathways and biotransformation products over time and fungal growth stages. Two Ascomycete fungi were grown with moderate (0.1 mM) and high (0.5 mM) Se(IV) concentrations in batch culture over 1 month. Fungal growth was measured throughout the experiments, and aqueous and biomass-associated Se was quantified and speciated using analytical geochemistry, transmission electron microscopy (TEM), and synchrotron-based X-ray absorption spectroscopy (XAS) approaches. The results show that Se transformation products were largely Se(0) nanoparticles, with a smaller proportion of volatile, methylated Se compounds and Se-containing amino acids. Interestingly, the relative proportions of these products were consistent throughout all fungal growth stages, and the products appeared stable over time even as growth and Se(IV) concentration declined. This time-series experiment showing different biotransformation products throughout the different growth phases suggests that multiple mechanisms are responsible for Se detoxification, but some of these mechanisms might be independent of Se presence and serve other cellular functions. Knowing and predicting fungal Se transformation products has important implications for environmental and biological health as well as for biotechnology applications such as bioremediation, nanobiosensors, and chemotherapeutic agents.

Effects of organic and inorganic selenium on selenium bioavailability, growth performance, antioxidant status and meat quality of a local beef cattle in China.

Selenium (Se) is an essential nutrient with multiple health benefits to humans and animals. Cattle generally require dietary Se supplementation to meet their daily requirements. The two main forms of dietary Se in cattle are organic Se and inorganic Se. Data comparing the health and productivity effects of organic Se and inorganic Se on cattle are still insufficient, and it is necessary to conduct more research to evaluate the bioavailability, nutritional value, deposition, and body functions of Se sources in different breeds and physiological stages of cattle raised in areas with different Se levels. The objectives of this study were to determine the effects of organic and inorganic sources of Se on plasma biochemical indices, Se bioavailability, deposition in body tissues and organs, growth performance, antioxidant capacity and meat quality of beef cattle raised in Se-deficient areas. Fifteen Chinese Xiangzhong Black beef cattle with an average weight of 254.5 ± 8.85 kg were assigned to three dietary groups. The three groups were fed the same basal ration and supplemented with either an inorganic [sodium selenite (SS)] or organic [selenomethionine (SM) or Se-enriched yeast (SY)] source of Se (0.1 mg/kg dry matter) for 60 days. At the end of the experiment, three cattle from each group were randomly selected and slaughtered, and samples were collected from tissues and organs for analysis. The results revealed that growth performance, slaughter performance, Se content of tissues and organs, meat quality characteristics including chemical composition, pH45min, pH24h, drip loss, and cooking losses did not differ (p > 0.05) due to supplementation of the different organic and inorganic sources of Se. SM and SY were more effective in increasing (p < 0.05) immunoglobulin M (IgM) concentrations in the blood and reducing (p < 0.05) malondialdehyde (MDA) content in the longissimus dorsi than SS. In conclusion, organic Se is more effective than inorganic Se in improving the immune and antioxidant capacity of Chinese Xiangzhong Black beef cattle.

The effect of selenium on antioxidant system in aquaculture animals.

There will be generated some adverse conditions in the process of acquculture farming with the continuous improvement of the intensive degree of modern aquaculture, such as crowding stress, hypoxia, and malnutrition, which will easily lead to oxidative stress. Se is an effective antioxidant, participating and playing an important role in the antioxidant defense system of fish. This paper reviews the physiological functions of selenoproteins in resisting oxidative stress in aquatic animals, the mechanisms of different forms of Se in anti-oxidative stress in aquatic animals and the harmful effects of lower and higher levels of Se in aquaculture. To summarize the application and research progress of Se in oxidative stress in aquatic animals and provide scientific references for its application in anti-oxidative stress in aquaculture.

Nano-Sized Selenium Maintains Performance and Improves Health Status and Antioxidant Potential While Not Compromising Ultrastructure of Breast Muscle and Liver in Chickens.

The poultry industry is looking for the most effective sources of selenium (Se) for commercial use. Over the past five years, nano-Se has attracted a great deal of attention in terms of its production, characterisation and possible application in poultry production. The objective of this study was to evaluate the effects of dietary levels of inorganic and organic Se, selenised yeast and nano forms of selenium on breast meat quality, liver and blood markers of antioxidants, the ultrastructure of tissue and the health status of chickens. A total of 300 one-day-old chicks Ross 308 were divided into 4 experimental groups, in 5 replications, with 15 birds per replication. Birds were fed the following treatments: a standard commercial diet containing inorganic Se in the form of inorganic Se at the level of 0.3 mg/kg diet and an experimental diet with an increased level of Se (0.5 mg/kg diet). The use of other forms of Se (nano-Se) versus sodium selenate significantly influences (p ≤ 0.05) a higher collagen content and does not impair physico-chemical properties in the breast muscle or the growth performance of the chickens. In addition, the use of other forms of selenium at an increased dose versus sodium selenate affected (p ≤ 0.01) the elongation of sarcomeres in the pectoral muscle while reducing (p ≤ 0.01) mitochondrial damage in hepatocytes and improving (p ≤ 0.05) oxidative indices. The use of nano-Se at a dose of 0.5 mg/kg feed has high bioavailability and low toxicity without negatively affecting the growth performance and while improving breast muscle quality parameters and the health status of the chickens.

Selenium Uptake, Translocation, and Metabolization Pattern during Barley Malting: A Comparison of Selenate, Selenite, and Selenomethionine.

Selenium (Se) is an essential trace element for human and animal health. Understanding the uptake and translocation of Se in crops is critical from the perspective of Se biofortification. In this study, barley was malted to investigate the uptake, translocation, and metabolism of exogenous Se including Na2SeO4, Na2SeO3, and selenomethionine (Se-Met). The results showed that the uptake rates of different forms of Se in barley decreased in the following order: Se-Met > Na2SeO3 > Na2SeO4, with the peak uptake occurring at the end of the steeping stages. In the early stages of germination, Se was mainly distributed in the husk and endosperm. Exogenous Se upregulated the transcription levels of Se transport and metabolic enzyme genes in the barley to varying degrees, which promoted Se transformation in various tissues, and improved Se bioeffectiveness. Compared to the Na2SeO3 and Se-Met groups, more Se was transferred from husk and endosperm to acrospire and rootlets in the Na2SeO4 group during the germination stage. Na2SeO4 and Se-Met stimulated the development of rootlets, and accelerated Se metabolism, resulting in a higher Se loss rate. Thus, these comparative findings provide new insights into Se uptake, transformation, and metabolization in barley.

Physiological Benefits of Novel Selenium Delivery via Nanoparticles

Dietary selenium (Se) intake within the physiological range is critical to maintain various biological functions, including antioxidant defence, redox homeostasis, growth, reproduction, immunity, and thyroid hormone production. Chemical forms of dietary Se are diverse, including organic Se (selenomethionine, selenocysteine, and selenium-methyl-selenocysteine) and inorganic Se (selenate and selenite). Previous studies have largely investigated and compared the health impacts of dietary Se on agricultural stock and humans, where dietary Se has shown various benefits, including enhanced growth performance, immune functions, and nutritional quality of meats, with reduced oxidative stress and inflammation, and finally enhanced thyroid health and fertility in humans. The emergence of nanoparticles presents a novel and innovative technology. Notably, Se in the form of nanoparticles (SeNPs) has lower toxicity, higher bioavailability, lower excretion in animals, and is linked to more powerful and superior biological activities (at a comparable Se dose) than traditional chemical forms of dietary Se. As a result, the development of tailored SeNPs for their use in intensive agriculture and as candidate for therapeutic drugs for human pathologies is now being actively explored. This review highlights the biological impacts of SeNPs on growth and reproductive performances, their role in modulating heat and oxidative stress and inflammation and the varying modes of synthesis of SeNPs.