Dietary Se Supplementation Research Articles

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.

Comparative effects of various dietary selenium sources on growth performance, meat quality, essential trace elements content, and antioxidant capacity in broilers

This study aimed to compare the effects of various dietary selenium (Se) sources (0.5 mg/kg) on performance, meat quality, and antioxidant capacity in broilers as well as essential trace elements concentrations in their blood and tissues. A total of 360 one-day-old male yellow-feathered chickens (37.00 ± 0.17 g) were randomly allocated to 5 diet treatments: the basal diet (CON) and 4 diets supplemented with sodium selenite (SS), selenomethionine (SM), selenium-enriched yeast (SY), and nano-selenium (NS) for 56 d, respectively, with 6 replicates per treatment and 12 chickens per replicate. Dietary Se supplementation did not affect growth performance and carcass characteristics in broilers (P > 0.05). Supplemental SM enhanced the redness in the pectoral muscle compared to CON and NS (P < 0.05). Supplementation of SY and NS improved the concentrations of Se, copper, manganese, and zinc in the serum (P < 0.05). Supplemental SS also elevated the zinc content in the serum (P < 0.05). Broilers fed the SY diet showed increased Se content in the liver and pectoral muscle compared to those fed CON, SM, and NS diets (P < 0.05). Also, SY improved the pectoral muscle Se concentration compared to SS (P < 0.05). Besides, dietary Se supplementation increased the Se content in the thigh muscle (P < 0.05), with SY showing highest Se deposition. Dietary supplementation with SS, SM, and NS improved the activities of total superoxide dismutase and total antioxidant capacity (T-AOC) in the serum (P < 0.05). Supplemental SY also elevated the T-AOC in the serum (P < 0.05). Additionally, SS and SM enhanced the T-AOC in the liver (P < 0.05). In conclusion, supplemental SM affected meat color. Supplementing diets with various Se sources increased antioxidant capacity and Se content in the thigh muscle of broilers, with SY showing a more pronounced deposition efficiency. Besides, diets supplemented with different Se sources had variable effects on the concentrations of essential trace elements in the serum and tissues of broilers.

Selenium-Rich Black Soldier Fly Supplementation Enriches Serum Indexes and Egg Selenium Content in Laying Hens.

A certain amount of selenium (Se) is usually added to the diet of laying hens to improve the quality and nutritional value of eggs. The present study was carried out to investigate the effect of selenium-rich black soldier fly (BSF) supplementation in diets on laying production performance, egg quality, serum indexes, and egg selenium content of Hy-line variety brown laying hens. A total of 288 at 49-week-old healthy laying hens were divided into 3 treatment groups with 6 replicates per group and 16 hens per replicate using a single-factor completely randomized design. Treatments consisted of (1) control (basal diet without supplemental Se), (2) 0.30mg/kg supplemental Se, (Se as sodium selenite, SS), and (3) 0.30mg/kg supplemental Se (Se as selenium-rich black soldier fly, SE-BSF). Laying performance was not affected by dietary Se. There was no effect of selenium-rich BSF on egg quality (P > 0.05). The contents of malonaldehyde (MDA) were significantly reduced (P < 0.05). On the contrary, dietary Se supplementation increased the activity of superoxide dismutase (SOD, P < 0.05) and catalase (CAT, P < 0.05) and increased the concentration of reduced glutathione (P < 0.05). In addition, selenium-rich BSF supplementation significantly increased the Se content of eggs (P < 0.05). These results indicate that Se supplementation did not affect laying production performance and egg quality of laying hens, but the supplementation could improve antioxidant capacity and increased the Se content of eggs.

Comparison of different organic selenium supplementations on selenium status and serum biomarkers in dairy cows.

The objective of this study was to investigate the effects of two different organic selenium (Se) supplements, selenomethionine (Se-Met) and selenohomolanthionine (Se-Hlan), on the serum biochemical parameters and Se status of dairy cows. Different dietary Se supplementation treatments were set as follows: a control group (CON, adding sodium selenite at 0.3mg Se/kg dry matter [DM]), 0.3 and 0.5 Se-Met (adding Se-Met at 0.3 and 0.5mg Se/kg DM, respectively), as well as 0.3 and 0.5 Se-Hlan (adding Se-Hlan at 0.3 and 0.5mg Se/kg DM, respectively). The experiment lasted 8weeks. The serum measurements showed that both organic Se treatments resulted in higher uric acid than CON. Se-Met produced higher aspartate aminotransferase, glucose, urea, low-density lipoprotein cholesterol, and lactate dehydrogenase than Se-Hlan. Regarding the Se status, the highest milk Se values appeared in 0.5 Se-Met, with intermediate values in 0.3 Se-Met and 0.5 Se-Hlan, whereas the highest and lowest serum Se levels were presented in 0.5 Se-Met and 0.3 Se-Hlan, respectively. Our results suggest that Se-Hlan was not as efficient in boosting serum or milk Se as Se-Met and differences in serum biomarkers between Se-Met and Se-Hlan may be associated with distinct metabolic pathways for different forms of organic Se.

Effects of various selenium-enriched yeasts, selenomethionine, and nanoselenium on production performance, quality, and antioxidant capacity in laying hens

This study aimed to compare the effects of various selenium (Se) sources (2 mg/kg) on the performance, quality, and antioxidant capacity of laying hens as well as the Se content in their eggs and blood. We selected 720 34-wk-old Lohmann pink-shell laying hens were randomly assigned into 6 groups and fed a basal diet (control) or a basal diet supplemented with various Se sources (Se-enriched yeast, SY-A, SY-C, SY-N; selenomethionine SM, nano-Se SN) for 16 wk. There were 10 replicates of 120 hens per group. Dietary Se supplementation increased the egg production rate of all laying hens. Egg and serum Se deposition was highest in the SM group. Yolk color scores of SY-A and SY-N groups were significantly lower than those of other groups (P < 0.01). The protein height and Haugh unit were significantly lower in the SN group than in the other groups (P < 0.05). The yolk height was significantly higher in the SN and SY-N groups than in the SY-A group (P < 0.05). Dietary supplementation of selenium can improve the antioxidant capacity of laying hens. The SOD content of SM group was significantly lower than that of SY-A and SN group (P < 0.05). The malondialdehyde (MDA) content was significantly higher in the SM group than in the SY-A group (P < 0.05). The present work empirically demonstrated that the production performance of laying hens supplemented with 2 mg/kg Se was superior to that of the hens receiving only a basal diet. The SY-C group exhibited the best production performance, the SY-A group had the highest antioxidant capacity, and the SM group produced eggs with the highest level of Se enrichment.

Organic selenium and tocopherol supplementation for multiparous sows without adiabatic cooling: Effects on performance, milk composition, and serum antioxidant enzymes

The aim of this study was to evaluate the effects of dietary supplementation of organic selenium (Se) and tocopherol to peak producing and older sows without adiabatic cooling on physiological parameters, reproductive performance, milk composition, litter performance, and serum antioxidant enzymes. A total of 96 sows were allotted in a 4 × 2 factorial arrangement, with 4 experimental groups and 2 parity orders (3–4th and above 5th). The experimental groups consisted of: ACCon – sows with adiabatic cooling and fed with control diet; WACCon – sows without adiabatic cooling and fed with control diet; WACSe – sows without adiabatic cooling with dietary supplementation of 0.3 mg/kg organic Se; WACSeE – sows without adiabatic cooling with dietary supplementation of 0.3 mg/kg organic Se and 90 UI of tocopherol. During the experimental period, the average temperature and humidity were 27.8 °C and 78.4%, respectively. Sows that received adiabatic cooling had lower respiratory rate, rectal temperature, and neck temperature when compared to the others sows (P < 0.05). Sows supplemented with organic Se and tocopherol had shorter wean-to-estrus interval than those not supplemented (P < 0.05). Sows supplemented with organic Se and tocopherol had higher concentrations of glutathione peroxidase (GSH-Px) in relation to the other experimental groups and higher levels of superoxide dismutase (SOD) than non-supplemented sows (P < 0.05). Piglets from sows supplemented with organic Se and tocopherol showed higher levels of GSH-Px and SOD in relation to the other experimental groups (P < 0.05). Under equatorial climate conditions, dietary supplementation of organic Se and tocopherol for multiparous sows reduces wean-to-estrus interval and increase expression of enzymatic antioxidant of sows and piglets.

PSXIII-12 Effects of Dietary Mixed Sources of Selenium Supplementation on Immune Responses, Stress Parameter and Gut Microbiota of Weaned Pigs

Abstract Selenium (Se) is a micro-essential mineral, following the amount of Se can be appeared as selenosis or deficiency disease. Its representative role was the main compound of glutathione peroxidase as known antioxidant enzyme. This role closely relates to health of piglets. Popular form of Se was divided into organic Se (Ose) and inorganic Se (Ise) forms. Ose has greater bioavailability and costs and reduced toxicity than Ise. Mixed Se sources can save costs and improve bioavailability compared with single-source Se. This study was conducted to investigate the effects of dietary mixed Se supplementation on immune responses, stress parameter and gut microbiota of weaned pigs. Weaned pigs [n = 156; 7.85 ± 0.10 kg of initial body weight (BW)] were allotted to three dietary treatments (4 pigs/pen; 13 replicates/treatment) in a randomized complete block design (block: initial BW and sex) for 6 weeks. Dietary treatments were a corn-soybean based diet except for Se (CON), CON + 0.15 ppm Ose + 0.15 ppm Ise (A), and CON + 0.25 ppm Ose + 0.25 ppm Ise (B). On day 7, 14, and 42, blood samples were collected from randomly selected 6 pigs per treatment. The collected samples were used for immune responses and stress parameters like tumor necrosis factor-alpha, transforming growth factor beta1, interleukin-1beta, interleukin-6, and cortisol by using ELISA kits. On day 42, samples were collected to analyze microbial communities of pigs by 16s rRNA sequencing method. Microbial communities were analyzed using QIIME. The microbial alpha diversity indices such as number of OTUs, Chao1, Shannon, and Inverse Simpson were calculated to measure the within-sample diversity and richness at the species level. The microbial beta diversity was performed to inter-sample dissimilarities using weighted UniFrac distances based on principal coordinate analysis. Data were analyzed using PROC MIXED procedure of SAS. The experimental unit was a pen. The statistical model for immune responses, stress parameters and gut microbiota included dietary treatment as main effect and initial BW as a covariate. No differences were found on immune responses and stress parameters among dietary treatments. The number of OTUs, Chao1, Shannon, and Inverse Simpson were not different among dietary treatments. The Se increased (P &amp;lt; 0.05) relative abundance of phylum Bacteroidetes but decreased (P &amp;lt; 0.05) phylum Firmicutes. In addition, the Se increased (P &amp;lt; 0.05) relative abundance of genus Barnesiella but decreased (P &amp;lt; 0.05) genus Lactobacillus. In conclusion, addition of 0.3 and 0.5 ppm mixed Se can alter gut microbiota.

PSXIII-9 Effects of Dietary Mixed Selenium Supplementation on Growth Performance, Frequency of Diarrhea, and Blood Profiles and Biochemical Constituents of Weaned Pigs

Abstract Selenium (Se) is known as a micro essential mineral that acts as a component of the powerful antioxidant enzymes as known glutathione peroxidase. However, both excess and deficiency of Se can lead to health problems in swine, thus the proper amount is needed. In the swine industry, organic and inorganic forms of Se are commonly added to the feed, mixing these Se is important to maximize the efficiency of Se utilization. This study was conducted to evaluate the effects of dietary mixed Se supplementation on growth performance, frequency of diarrhea, and blood profiles and biochemical constituents of weaned pigs. A total of 156 weaned pigs [(Landrace × Yorkshire) × Duroc; 7.85 ± 0.10 kg of initial body weight (BW); 28 days of age] were assigned to 3 dietary treatments (4 pigs/pen; 13 replicates/treatment) in a randomized complete block design (block = initial BW and sex) for 6 weeks. Dietary treatments were 1) a corn- soybean meal-based diet with deficiency of Se (CON), 2) CON + 0.15 ppm organic Se (Ose) + 0.15 ppm inorganic Se (Ise; A), and 3) CON+ 0.25 ppm Ose + 0.25 ppm Ise (B). On day 7, 14, and 42, blood samples were collected from randomly selected 6 pigs per treatment to analyze blood profiles and biochemical constituents. Average daily gain, average daily feed intake, and gain to feed ratio were calculated to evaluate growth performance. The frequency of diarrhea was calculated by visual observation for 2 weeks after weaning. The number of white blood cells, red blood cells, hemoglobin (HGB), hematocrit (HCT), and mean corpuscular hemoglobin (MCH) were measured using an automated hematology analyzer. The collected serum samples were analyzed for total protein (TP), glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, and blood urea nitrogen (BUN) using a specific kit and a clinical auto-analyzer. Data were analyzed using GLM procedures of SAS. The experimental unit was a pen. The statistical model for growth performance, and blood profiles and biochemical constituents included dietary treatment as a main effect and initial BW as a covariate. The Chi-square test was used for analyzing frequency of diarrhea. The A treatment decreased (P &amp;lt; 0.10) MCH, HGB, HCT, and BUN on day 42 compared with CON, but increased (P &amp;lt; 0.05) TP on day 42. However, there were no differences on growth performance and frequency of diarrhea. In conclusion, supplementation of dietary mixed Se could modulate blood profiles and biochemical constituents.

Organic selenium and vitamin E for gilts and sows bred in equatorial climate.

The aim of this study was to evaluate the dietary supplementation of organic selenium (Se) and vitamin E for sows from 1st and 2nd parity order, without adiabatic cooling on physiological parameters, reproductive performance, milk composition, litter performance and blood concentrations of antioxidant enzymes. A total of 96 sows were allotted in a 4 × 2 completely factorial design, with 4 experimental groups and 2 parity orders (1st and 2nd). The experimental groups consisted of: ACCon-sows receiving adiabatic cooling and no dietary supplementation of organic Se and vitamin E; WACCon-sows without adiabatic cooling and no dietary supplementation of organic Se and vitamin E; WACSe-sows without adiabatic cooling with dietary supplementation of 0.3 mg/kg organic Se; WACSeE-sows without adiabatic cooling with dietary supplementation of 0.3 mg/kg organic Se and 90 UI of vitamin E. ACCon Sows had lower respiratory rate, rectal temperature and body surface temperature when compared to the others sows (p < 0.05). Sows without evaporative cooling had lower daily milk production and weaned litters with lower weight and average daily gain when compared to the other groups (p < 0.05). ACCon sows presented higher weaned piglets to WACSeE sows. WACSeE Sows had higher concentrations of GSH-Px when compared to other experimental groups and higher levels of SOD than sows from ACCon and WACSe. Piglets of sows from WACSeE group presented higher levels of GSH-Px and SOD when compared to the other experimental groups. ACCon sows have higher milk yield and higher litter weight than others groups. Under equatorial climate conditions, dietary supplementation of organic Se and vitamin E from first and second parity order sows does not respond efficiently on thermoregulatory physiology and performance compared to adiabatic cooling, but modulates the enzymatic antioxidant balance of sows and piglets.

Protective role of selenium and selenium-nanoparticles against multiple stresses in Pangasianodon hypophthalmus.

Pollution and climate change pose significant threats to aquatic ecosystems, with adverse impacts on aquatic animals, including fish. Climate change increases the toxicity of metal in aquatic ecosystems. To understand the severity of metal pollution and climate change, an experiment was conducted to delineate the mitigation potential of selenium (Se) and selenium nanoparticles (Se-NPs) against lead (Pb) and high temperature stress in Pangasianodon hypophthalmus.For the experiment, five isonitrogenous and isocaloric diets were prepared, varying in selenium supplementation as Se at 0, 1, and 2 mg kg-1 diet, and Se-NPs at 1 and 2 mg kg-1 diet. The fish in stressor groups were exposed to Pb (1/20th of LC50 concentration, 4 ppm) and high temperature (34 °C) throughout the experiment. The results demonstrated that dietary supplementation of Se at 1 and 2 mg kg-1 diet, as well as Se-NPs at 1 mg kg-1 diet, significantly reduced (p< 0.01) the levels of lactate dehydrogenase and malate dehydrogenase in both liver and muscle tissues. Additionally, the levels of alanine aminotransferase and aspartate aminotransferase in both gill and liver tissues were significantly decreased (p< 0.01) with the inclusion of Se and Se-NPs in the diets. Furthermore, the enzymes glucose-6-phosphate dehydrogenase in gill and liver tissues, fructose 1,6-bisphosphatase in liver and muscle tissues, and acid phosphatase in liver tissue were remarkably reduced (p< 0.01) due to the supplementation of Se and Se-NPs. Moreover, dietary supplementation of Se and Se-NPs significantly enhanced (p< 0.01) the activity of pyruvate kinase, glucokinase, hexokinase, alkaline phosphatase, ATPase, protease, amylase, lipase, and RNA/DNA ratio in the fish. Histopathological examination of gill and liver tissues also indicated that Se and Se-NPs protected against structural damage caused by lead and high-temperature stress. Moreover, the study examined the bioaccumulation of selenium and lead in muscle, water, and diets. The aim of the study revealed that Se and Se-NPs effectively protected the fish from lead toxicity and high-temperature stress, while also improving the function of cellular metabolic enzymes in P. hypophthalmus.

Fractionation of selenium isotopes during biofortification of Saccharomyces cerevisiae and the influence of metabolic labeling with 15N.

Isotope fractionation of metals/metalloids in biological systems is an emerging research area that demands the application of state-of-the-art analytical chemistry tools and provides data of relevance to life sciences. In this work, Se uptake and Se isotope fractionation were measured during the biofortification of baker's yeast (Saccharomyces cerevisiae)-a product widely used in dietary Se supplementation and in cancer prevention. On the other hand, metabolic labeling with 15N is a valuable tool in mass spectrometry-based comparative proteomics. For Se-yeast, such labeling would facilitate the assessment of Se impact on yeast proteome; however, the question arises whether the presence of 15N in the microorganisms affects Se uptake and its isotope fractionation. To address the above-mentioned aspects, extracellularly reduced and cell-incorporated Se fractions were analyzed by hydride generation-multi-collector inductively coupled plasma-mass spectrometry (HG MC ICP-MS). It was found that extracellularly reduced Se was enriched in light isotopes; for cell-incorporated Se, the change was even more pronounced, which provides new evidence of mass fractionation during biological selenite reduction. In the presence of 15N, a weaker preference for light isotopes was observed in both, extracellular and cell-incorporated Se. Furthermore, a significant increase in Se uptake for 15N compared to 14N biomass was found, with good agreement between hydride generation microwave plasma-atomic emission spectrometry (HG MP-AES) and quadrupole ICP-MS results. Biological effects observed for heavy nitrogen suggest 15N-driven alteration at the proteome level, which facilitated Se access to cells with decreased preference for light isotopes.

Selenium Ameliorated Oxidized Fish Oil-Induced Lipotoxicity via the Inhibition of Mitochondrial Oxidative Stress, Remodeling of Usp4-Mediated Deubiquitination, and Stabilization of Pparα.

Aims: Studies demonstrated that oxidized fish oil (OFO) promoted oxidative stress and induced mitochondrial dysfunction and lipotoxicity, which attenuated beneficial effects of fish oil supplements in the treatment of nonalcoholic fatty liver disease (NAFLD). The current study was performed on yellow catfish, a good model to study NAFLD, and its hepatocytes to explore whether selenium (Se) could alleviate OFO-induced lipotoxicity via the inhibition of oxidative stress and determine its potential mechanism. Results: The analysis of triglycerides content, oxidative stress parameters, and histological and transmission electronic microscopy observation showed that high dietary Se supplementation alleviated OFO-induced lipotoxicity, oxidative stress, and mitochondrial injury and dysfunction. RNA-sequencing and immunoblotting analysis indicated that high dietary Se reduced OFO-induced decline of peroxisome-proliferator-activated receptor alpha (Pparα) and ubiquitin-specific protease 4 (Usp4) protein expression. High Se supplementation also alleviated OFO-induced reduction of thioredoxin reductase 2 (txnrd2) messenger RNA (mRNA) expression level and activity. The txnrd2 knockdown experiments revealed that txnrd2 mediated Se- and oxidized eicosapentaenoic acid (oxEPA)-induced changes of mitochondrial reactive oxygen species (mtROS) and further altered Usp4 mediated-deubiquitination and stabilization of Pparα, which, in turn, modulated mitochondrial fatty acid β-oxidation and metabolism. Mechanistically, Usp4 deubiquitinated Pparα and ubiquitin-proteasome-mediated Pparα degradation contributed to oxidative stress-induced mitochondrial dysfunction. Innovation: These findings uncovered a previously unknown mechanism by which Se and OFO interacted to affect lipid metabolism via the Txnrd2-mtROS-Usp4-Pparα pathway, which provides the new target for NAFLD prevention and treatment. Conclusion: Se ameliorated OFO-induced lipotoxicity via the inhibition of mitochondrial oxidative stress, remodeling of Usp4-mediated deubiquitination, and stabilization of Pparα. Antioxid. Redox Signal. 40, 433-452.

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.

Dietary selenium requirement for on-growing grass carp, Ctenopharyngodon idellus

Selenium (Se) is an essential trace element for fish. Appropriate dietary Se supplementation is essential for fish's normal growth and health. This study was conducted to explore the dietary Se requirement of on-growing grass carp (Ctenopharyngodon idellus) (73.27 ± 0.12 g) using selenium yeast (Se-yeast) as the Se source. Graded levels of Se-yeast were added to the basal diet at 0, 0.125, 0.25, 0.5, 1.0, 2.0, and 4.0 mg Se/kg diet providing the analyzed Se of 0.05, 0.18, 0.30, 0.57, 1.05, 2.21 and 4.21 mg/kg, respectively. After 56-day culture, the final body weight and weight gain rate (WGR) were significantly increased in fish fed with 0.57 to 2.21 Se/kg diet while feed conversion ratio (FCR) showed the inverse pattern (P < 0.05). The specific growth rate (SGR) was significantly increased with incensing dietary Se levels up to 2.21 mg Se/kg diet (P < 0.05). Antioxidant enzyme activities in the liver and plasma were significantly increased in fish fed with 0.57–4.21 mg Se/kg diet (P < 0.05). Malondialdehyde (MDA) contents in the liver and plasma were significantly decreased and then increased with dietary Se supplementation (P < 0.05). Transcript levels of 6 selenoprotein genes in the liver (gpx1a, gpx4a, selp, selw, selk, and dio1) and 7 selenoprotein genes in muscle (gpx1a, gpx4a, gpx4b, selp, selw, selk, and dio1) were significantly increased with increasing dietary Se levels (P < 0.05). Based on broken-line regression analysis of WGR, SGR, and FCR, the optimal dietary Se requirement for on-growing grass carp was 0.915–1.026 mg Se/kg diet. A dietary Se level of 4.21 mg/kg could be toxicity for on-growing grass carp characterized by depressed growth and increased MDA content.

Interaction between dietary selenium and methylmercury on growth performance, deposition and health parameters in rainbow trout fed selenium-rich tuna-based diets or selenium-poor plant-based diets

This study evaluated the effect of dietary mercury (Hg) and selenium (Se) sources and levels on growth performance, Hg and Se accumulation, pro-inflammatory cytokine levels and global health parameters in rainbow trout juveniles. A 6-month feeding trial was carried out with a control plant-based diet (containing analyzed Se and Hg levels: 0.3 and 0 mg/kg diet, respectively) or a control tuna-based diet (containing analyzed Se and Hg levels: 7.5 and 0.3 mg/kg diet, respectively) supplemented with 0 or 1.5 mg Se/kg diet supplied either as sodium selenite (Se(IV)) or selenomethionine (SeMet) combined with 0, 1.6 or 2 mg Hg/kg diet supplied as methylmercury (MeHg). Fish sampling was carried out at 2 times: after a short (21 days) and a long term dietary exposure (168 days). In the short term, a temporarily reduced growth was noticed in fish fed MeHg-supplemented plant-based diet in absence of dietary Se supplementation. MeHg supplementation increased pro-inflammatory cytokine TNF-α and IL-1β levels in plant and tuna-based diets. MeHg supplementation also affected short-term fish global health parameters with an increase of glucose and albumin levels in tuna-based diets. The addition of SeMet in MeHg-supplemented tuna-based diets protected against the increase of TNF-α level in the long term whereas the addition of Se(IV) in MeHg-supplemented tuna-based diets decreased whole-body Hg level and retention in the short term. In the long term, a reduced growth, a higher feed conversion ratio and a lower protein efficiency ratio were recorded in fish fed Se(IV)-supplemented tuna-based diets in absence of MeHg supplementation. The addition of Se(IV) or SeMet in tuna-based diets increased plasma IL-6 level. The addition of MeHg in plant and tuna-based diets increased Se accumulation and retention. This work underlines that different forms of Se supplementation, in two dietary background context (low basal Se level in plant-based diets and high basal Se level in tuna-based diets), have specific effects on metabolism and biological consequences of dietary MeHg. Dietary inorganic Se (but not organic Se) affected MeHg metabolism by reducing Hg accumulation in fish. However, dietary organic Se displayed better ability to afford protection against MeHg pro-inflammatory effects.

Ameliorative effects of different doses of selenium against fluoride-triggered apoptosis and oxidative stress-mediated renal injury in rats through the activation of Nrf2/HO-1/NQO1 signaling pathway.

Excess fluoride (F) exposure can cause oxidative stress in the kidney. As an antioxidant, selenium (Se) can potentially protect the kidney from F-induced injury in rats. Hence, the histopathological, renal biochemical, oxidative stress, and apoptotic-related indices upon exposure to 100mg/L sodium fluoride (NaF) and various doses of sodium selenite (Na2SeO3; 0.5, 1, and 2mg/L) were assessed. Our results demonstrated that F-mediated renal structural damage and apoptosis elevated the content of serum creatinine (SCr), inhibited the activity of catalase (CAT) in serum, and increased the production of reactive oxygen species (ROS) in kidney and malondialdehyde (MDA) in serum. Interestingly, 1mg/L dietary supplementation of Se tangibly mitigated these injuries. Furthermore, F could also change the gene and protein expression of the nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and NAD(P)H quinone oxidoreductase1 (NQO1). Concomitantly, the different concentrations of Se notably alleviated their expression. Taken together, 1-2mg/L Se ameliorated F-induced renal injury through oxidative stress and apoptosis-related routes. The recorded ameliorative effects might be related to the activation of the Nrf2/HO-1/NQO1 signaling pathway.

Selenium Requirements of Rats for Normal Hepatic and Thyroidal 5′-Deiodinase (Type I) Activities

The nutritional requirement of selenium for type I 5'-deiodinase activity in thyroid compared with liver was assessed in rats. Male weanling Sprague-Dawley rats were fed a torula yeast-based diet for 20 wk. One group of rats was fed the Se-deficient basal diet (0.01 mg Se/kg). The other three groups were fed the basal diet plus sodium selenite at 0.05, 0.1 and 0.5 mg Se/kg diet. Liver 5'-deiodinase and glutathione peroxidase (GSH-Px) activities were depressed in the group fed the Se-deficient (basal) diet compared with the other groups. Liver 5'-deiodinase activity in the group fed 0.05 mg Se/kg diet was as high as in the groups fed 0.1 and 0.5 mg Se/kg diet, whereas GSH-Px activities in the groups fed 0.05 and 0.1 mg Se/kg diet were intermediate in value. Feeding the Se-deficient diet for 20 wk did not cause a suppression in 5'-deiodinase in the thyroid, and thyroid GSH-Px activity was approximately 40% of that in the other groups. In rats fed Se-supplemented diets, thyroid GSH-Px was approximately 20% or less of the activity found in liver. Plasma thyroxine was higher in the group fed the Se-deficient (basal) diet, but there were no differences in plasma 3,3',5-triiodothyronine among all groups. The results suggest that the nutritional Se requirement for 5'-deiodinase is less than that for GSH-Px and is approximately 0.05 mg Se/kg in the diet for normal activity in the liver and approximately 0.01 mg Se/kg for normal activity in the thyroid. Thyroid seems to be a priority organ over liver for Se when the intake of the element is limited.

Effects of Different Drying Methods on the Selenium Bioaccessibility and Antioxidant Activity of Cardamine violifolia

Understanding the effects of drying on the selenium (Se) content and Se bioaccessibility of Se-rich plants is critical to dietary supplementation of Se. The effects of five common drying methods (far-infrared drying (FIRD), vacuum drying (VD), microwave vacuum drying (MVD), hot air drying (HD), and freeze vacuum drying (FD)) on the content and bioaccessibility of Se and Se species in Cardamine violifolia leaves (CVLs) were studied. The content of SeCys2 in fresh CVLs was the highest (5060.50 μg/g of dry weight (DW)); after FIRD, it had the lowest selenium loss, with a loss rate of less than 19%. Among all of the drying processes, FD and VD samples had the lowest Se retention and bioaccessibility. FIRD, VD, and FD samples have similar effects on antioxidant activity.

Antitumor effect of selenium-rich Brazil nuts and selenomethionine dietary supplementation on pre-existing 4T1 mammary tumor growth in mice.

Selenium (Se) is an essential micronutrient known to play an important role in the antioxidant system that can potentially influence tumor growth. We aimed to investigate the effects of dietary Se supplementation after detection of 4T1 mammary tumor growth in BALB/c mice. Thirty female mice received subcutaneous inoculation of 4T1 cells. After five days, all animals presenting palpable tumors were randomly assigned to three groups: a control group (Se-control) receiving a diet with adequate Se (0.15 mg/kg) and two other groups that received Se-supplemented diets (1.4 mg/kg of total Se) with either Brazilian nuts (Se-Nuts) or selenomethionine (SeMet). Data were assessed by either One or Two-way ANOVA followed by Tukey's HSD or Bonferroni's post hoc tests, respectively. Both Se-supplemented diets reduced tumor volume from the thirteenth day of feeding compared with the Se-adequate (control) diet (p < 0.05). The SeMet group presented a higher Se blood concentration (p < 0.05) than the Se-control group, with the Se-Nuts group presenting intermediate values. Selenoprotein P gene expression in the liver was higher in the Se-Nuts group than in the Se-control group (p < 0.05), while the SeMet group presented intermediate expression. Dietary Se supplementation, starting after detection of 4T1 palpable lesions, reduced tumor volume in mice.

Effect of dietary supplementation of organic and inorganic Se on performance and antioxidant response in commercial broiler chickens

ABSTRACT 1. The study was carried out to determine the effects of supplementing organic (OG) or inorganic (IOG) Se to record the performance, immune and anti-oxidant response in broiler chickens. 2. One-day-old Vencobb-400 (50.1 ± 0.84 g; n = 280) male broiler chicks were allocated randomly into seven treatments to give eight replicates containing five chicks each and housed in deep littered floor pens (76 cm × 91 cm) for a period of 42 d. 3. The control diet (CD) was formulated without any Se supplementation (diet I), CD plus 0.15, 0.30 or 0.45 mg/kg OG Se (diets II, III and IV, respectively) and CD plus 0.15, 0.30 or 0.45 mg/kg IOG Se (diets V, VI and VII, respectively). 4. Feed intake (FI), body weight gain (BWG), immune variables and mRNA expression profile of hepatic selenoproteins (SepW, GSHPx1, TrxR and GSHPx3) genes were determined. The BWG, FI and feed conversion ratio did not differ among various dietary treatments. 5. The lipid peroxidation and activity of RBC catalase were lower (P < 0.05) in groups fed diets supplemented OG Se compared to those fed IOG Se and CD. The activity of GSH Px was higher among the groups fed diet supplemented OG Se compared to those groups fed OG Se and CD. However, supplementing diets with OG or IOG Se did not affect humoral or cell mediated immune responses. 6. The expression levels of SepW were higher (P < 0.01) among the groups supplemented with OG Se. Expression levels of GSH-Px1, TrxR and GSHPx3 were higher (P < 0.01) among the groups supplemented with OG Se compared to those groups fed IOG Se or CD. 7. Supplementing OG Se improved the activities of anti-oxidant enzymes and hepatic expression of selenoproteins genes in the present study. However, supplementing OG or IOG Se did not affect growth performance and immune variables in broiler chickens.