Description of lesions in lambs intoxicated with sodium selenite included in intraruminal boluses: Lambs intoxicated with selenium.

Selenium is an essential micronutrient for ruminants, which participates in the optimal functioning of proteins and enzymes that can combat oxidative stress in the body; however, its toxicity is documented in different species. The objective of this work was to describe macroscopic and microscopic lesions in lambs intoxicated with selenium administered through intraruminal boluses. The main lesions at necropsy were pulmonary oedema; the myocardial surface presented multifocal pale areas; the thyroid and thymus glands were decreased in size, and areas of necrosis, haemorrhage and hyperkeratosis were observed in the reticulum and rumen. At the microscopic level, congestion, haemorrhage, oedema and hyaline membranes were observed in the lung; hepatic congestion, haemorrhage, degeneration and necrosis; degeneration and necrosis of the reticulum mucosa, as well as areas of hyperplasia and hyperkeratosis; myocardial degeneration, necrosis and fibrosis; congestion, haemorrhage, degeneration and renal tubular necrosis; thyroid follicular atrophy and thymic cortical atrophy. This study evidenced the main lesions related to selenium poisoning in lambs supplemented with the mineral through intraruminal boluses.

[Improving effect of selenium on spermatogenesis in mice with cyclophosphamide-induced spermatogenic impairment and its underlying mechanism].

OBJECTIVE: To investigate the effect of selenium on cyclophosphamide (CTX)-induced spermatogenic impairment (SI) in mice and its underlying mechanism. METHODS: We equally randomized 36 male KM mice into 3 SI model and 3 control groups, the first 3 treated by intraperitoneal injection of CTX at 100 mg/kg (the SI model control group), CTX plus SI model control group, selenium deficient model group (－Se SI), selenium supplemented model group (+Se SI), while latter 3 by intraperitoneal injection of normal saline (the normal control), selenium deficiency control group (－Se control), selenium addition control group (+Se control), respectively, all once a week for 6 successive weeks. Then we observed the histopathological changes in the testes of all the mice by HE staining, obtained the sperm count in the epididymides, determined the expressions of glutathione peroxidase 4 (GPx4) and SLC7A11 proteins by Western blot and ferroptosis-related genes by RT-qPCR, and examined the changes in the expressions of ferroptosis-related proteins and genes in the GC2-spd cells treated with ferroptosis inhibitors and inducers in combination with different concentrations of inorganic sodium selenite (SeS) and organic selenomethionine (SeM). RESULTS: Compared with the normal controls, the SI model mice showed significantly decreased testicular and prostatic organ coefficients, reduced spermatogenic layers, increased voids, decreased serum ferritin concentration (P<0.05), and elevated transferrin concentration (P<0.05). The organ coefficients were significantly higher in the +Se SI and +Se control than in the －Se SI and －Se control groups (P<0.05, P<0.01), with evident pathological improvement of the testis tissue in the +Se controls. The expressions of the GPx4 and solute carrier family 7 members 11（SLC7A11） genes in the testis were dramatically down-regulated in the SI model controls (P<0.01), but up-regulated in the +Se SI and +Se control compared with those in the －Se SI and －Se control group (P<0.01 and P<0.05), but there were no statistically significant differences between their protein expressions. The results of in vitro GC2 spd cell experiments indicated that the GPx4 gene and GPx4 protein levels in the - Se group were significantly lower than those in the normal control group (P<0.05), while the SLC7A11 gene level decreased (P<0.01). Different doses of SeS and SeM significantly increased the GPx4 protein expression compared to the average Se group. Low doses of SeM promoted a significant increase in GPx4 gene levels, while high doses of SeS increased the expression levels of SLC7A11 gene and SLC7A11 protein (P<0.05, P<0.01). The Se group showed a significant decrease in the levels of acsl4 and ptgs2 genes compared to the normal control group. SeM promoted the expression of acsl4, while SeS promoted the expression of ptgs2 and fth1 (P<0.01, P<0.05). The intervention results of GC2 spd showed that the Erastin group had a decrease in ptgs2 compared to the normal control group, while the SeS+Erastin and SeM+Erastin groups had an increase in ptgs2 gene expression compared to the Erastin group. However, the ptgs2 expression of Fer-1 was lower than that of the normal control group, and the ptgs2 gene level of SeS+Fer-1 and SeM+Fer-1 groups was lower than that of Fer-1 group (P<0.05); The gene quantity of GPx4 in the SeM+Erastin and SeM+Fer-1 groups increased compared to the Erastin and Fer-1 groups (P<0.01, P<0.05); SeM+Erastin and SeS+Erastin showed a decrease in SLC7A11 compared to the Erastin group, as well as SeM+Fer-1 and SeS+Fer-1 groups compared to the Fer-1 group, accompanied by an increase in acsl4 and fth1 (P<0.01). CONCLUSION: Selenium deficiency causes the reduction of the SLC7A11 and GPx4 gene levels, disorder of ferroptosis-related genes and down-regulation of the GPx4 protein expression in the mouse testis and spermatocytes. Selenium can promote the expression of GPx4, up-regulate the level of SLC7A11, and improve spermatogenesis in the testis of the mouse with SI. There are differences between organic SeM and inorganic SeS in regulating the ferroptosis pathway-related genes.

Effects of Foliar Dressing with Chemical Nano-Selenum and Na2SeO3 on the Antioxidant System and Accumulation of Se and Bioactive Components in Cyclocarya paliurus (Sweet Tea Tree).

Selenium (Se)-rich Cyclocarya paliurus is popular for its bioactive components, and exogenous Se fortification is the most effective means of enrichment. However, the effects of exogenous Se fortification on the nutritional quality of C. paliurus are not well known. To investigate the nutrient contents and antioxidant properties of C. paliurus following Se treatment, we used a foliar spray to apply Se in two forms-chemical nano-Se (Che-SeNPs) and sodium selenite (Na2SeO3). Sampling began 10 days after spraying and was conducted every 5 days until day 30. The Se, secondary metabolite, malondialdehyde contents, antioxidant enzyme activity, Se speciation, and Se-metabolism-related gene expression patterns were analyzed in the collected samples. Exogenous Se enhancement effectively increased the Se content of leaves, reaching a maximum on days 10 and 15 of sampling, while the contents of flavonoids, triterpenes, and polyphenols increased significantly during the same period. In addition, the application of Se significantly enhanced total antioxidant activity, especially the activity of the antioxidant enzyme peroxidase. Furthermore, a positive correlation between the alleviation of lipid peroxidation and Se content was observed, while methylselenocysteine formation was an effective means of alleviating Se stress. Finally, Na2SeO3 exhibited better absorption and conversion efficiency than Che-SeNPs in C. paliurus.

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.

Overexpression of Wheat Selenium-Binding Protein Gene TaSBP-A Enhances Plant Growth and Grain Selenium Accumulation under Spraying Sodium Selenite.

Selenium (Se) is an essential trace element for humans. Low concentrations of Se can promote plant growth and development. Enhancing grain yield and crop Se content is significant, as major food crops generally have low Se content. Studies have shown that Se biofortification can significantly increase Se content in plant tissues. In this study, the genetic transformation of wheat was conducted to evaluate the agronomic traits of non-transgenic control and transgenic wheat before and after Se application. Se content, speciation, and transfer coefficients in wheat grains were detected. Molecular docking simulations and transcriptome data were utilized to explore the effects of selenium-binding protein-A TaSBP-A on wheat growth and grain Se accumulation and transport. The results showed that TaSBP-A gene overexpression significantly increased plant height (by 18.50%), number of spikelets (by 11.74%), and number of grains in a spike (by 35.66%) in wheat. Under normal growth conditions, Se content in transgenic wheat grains did not change significantly, but after applying sodium selenite, Se content in transgenic wheat grains significantly increased. Analysis of Se speciation revealed that organic forms of selenomethionine (SeMet) and selenocysteine (SeCys) predominated in both W48 and transgenic wheat grains. Moreover, TaSBP-A significantly increased the transfer coefficients of Se from solution to roots and from flag leaves to grains. Additionally, it was found that with the increase in TaSBP-A gene overexpression levels in transgenic wheat, the transfer coefficient of Se from flag leaves to grains also increased.

Sodium selenite attenuates inflammatory response and oxidative stress injury by regulating the Nrf2/ARE pathway in contrast-induced acute kidney injury in rats.

BACKGROUND: Contrast-induced acute kidney injury (CI-AKI) is an acute renal complication that occurs after intravascular contrast agent administration. Sodium selenite (SS) is an inorganic source of Se and has potent antioxidant properties. This study intends to examine its anti-inflammatory and antioxidant effects in CI-AKI. METHODS: A rat CI-AKI model was established with the pretreatment of SS (0.35 mg/kg). Hematoxylin-eosin staining was employed for histopathological analysis of rat kidney specimens. Biochemical analysis was conducted for renal function detection. Tissue levels of oxidative stress-related markers were estimated. Reverse transcription-quantitative polymerase chain reaction revealed the mRNA levels of proinflammatory cytokines. Western blotting showed the Nrf2 signaling-related protein expression in the rat kidney. RESULTS: SS administration alleviated the renal pathological changes and reduced the serum levels of serum creatinine, blood urea nitrogen, neutrophil gelatinase-associated lipocalin, cystatin C, and urinary level of kidney injury molecule-1 in CI-AKI rats. SS attenuated oxidative stress and inflammatory response in CI-AKI rat kidney tissues. SS activated the Nrf2 signaling transduction in the renal tissues of rats with CI-AKI. CONCLUSION: SS ameliorates CI-AKI in rats by reducing oxidative stress and inflammation via the Nrf2 signaling.

Docosahexaenoic Acid Coordinating with Sodium Selenite Promotes Paraptosis in Colorectal Cancer Cells by Disrupting the Redox Homeostasis and Activating the MAPK Pathway.

Tumor cells are characterized by a delicate balance between elevated oxidative stress and enhanced antioxidant capacity. This intricate equilibrium, maintained within a threshold known as redox homeostasis, offers a unique perspective for cancer treatment by modulating reactive oxygen species (ROS) levels beyond cellular tolerability, thereby disrupting this balance. However, currently used chemotherapy drugs require larger doses to increase ROS levels beyond the redox homeostasis threshold, which may cause serious side effects. How to disrupt redox homeostasis in cancer cells more effectively remains a challenge. In this study, we found that sodium selenite and docosahexaenoic acid (DHA), a polyunsaturated fatty acid extracted from marine fish, synergistically induced cytotoxic effects in colorectal cancer (CRC) cells. Physiological doses of DHA simultaneously upregulated oxidation and antioxidant levels within the threshold range without affecting cell viability. However, it rendered the cells more susceptible to reaching the upper limit of the threshold of redox homeostasis, facilitating the elevation of ROS levels beyond the threshold by combining with low doses of sodium selenite, thereby disrupting redox homeostasis and inducing MAPK-mediated paraptosis. This study highlights the synergistic anticancer effects of sodium selenite and DHA, which induce paraptosis by disrupting redox homeostasis in tumor cells. These findings offer a novel strategy for more targeted and less toxic cancer therapies for colorectal cancer treatment.

Investigation of the protective effects of different forms of selenium in freezing dog semen: Comparison of nanoparticle selenium and sodium selenite.

This study aimed to investigate the protective effects of nanoparticle selenium (SeNP) and sodium selenite (SS) on preventing oxidative stress during the freezing process of dog semen. A total of six dogs were used in the study. The ejaculate was collected from dogs three times at different times by massage method. A total of 18 ejaculates were used and each ejaculate was divided in five experimental groups. The experimental groups were designed to tris extender containing no antioxidants control, 1 µg/mL SeNP1, 2 µg/mL SeNP2, and 1 µg/mL SS1 and 2 µg/mL SS2. Extended semen were equilibrated for 1 h at 4°C, then frozen in liquid nitrogen vapour and stored in liquid nitrogen (~-196°C). After thawing, semen samples were evaluated in terms of CASA motility and kinematic parameters, spermatozoa plasma membrane integrity and viability (HE Test), spermatozoa morphology (SpermBlue) and DNA fragmentation (GoldCyto). Antioxidant enzyme activity (glutathione peroxidase; GPX, superoxide dismutase; SOD, catalase; CAT) and lipid peroxidation (malondialdehyde; MDA) were evaluated in frozen-thawed dog sperm. When the results were evaluated statistically, the progressive motility, VCL, and VAP kinematic parameters in the SeNP1 group were significantly higher than the control group after thawing (p < .05). The highest ratio of plasma membrane integrity and viable spermatozoa was observed in the SeNP1 group, but there was no statistical difference found between the groups (p > .05). Although the ratio of total morphological abnormality was observed to be lower in all groups to which different selenium forms were added, compared to the control group, no statistical difference was found. Spermatozoa tail abnormality was significantly lower in the SeNP1 group than in the control and SS2 group (p < .05). The lowest ratio of fragmented DNA was observed in the SeNP1 group, but there was no statistical difference was found between the groups (p > .05). Although there was no statistical difference between the groups in the evaluation of sperm antioxidant profile, the highest GPX, SOD and CAT values and the lowest lipid peroxidation values were obtained in the SeNP1 group. As a result, it was determined that 1 µg/mL dose of SeNP added to the tris-based extender in dog semen was beneficial on spermatological parameters, especially sperm kinematic properties and sperm morphology, and therefore nanoparticle selenium, a nanotechnology product, made a significant contribution to the freezing of dog semen.

Selenoprotein-P1 (SEPP1) Expression in Human Proximal Tubule Cells after Ischemia-Reperfusion Injury: An In Vitro Model.

Background and Objectives: Selenium deficiency represents a risk factor for the occurrence of severe diseases, such as acute kidney injury (AKI). Recently, selenoprotein-p1 (SEPP1), a selenium transporter, mainly released by the liver, has emerged as a promising plasmatic biomarker of AKI as a consequence of cardio-surgery operations. The aim of the present study was to investigate, on an in vitro model of hypoxia induced in renal tubular cells, HK-2, the effects of sodium selenite (Na2SeO3) and to evaluate the expression of SEPP1 as a marker of injury. Materials and Methods: HK-2 cells were pre-incubated with 100 nM Na2SeO3 for 24 h, and then, treated for 24 h with CoCl2 (500 µM), a chemical hypoxia inducer. The results were derived from an ROS assay, MTT, and Western blot analysis. Results: The pre-treatment determined an increase in cells' viability and a reduction in reactive oxygen species (ROS), as shown by MTT and the ROS assay. Moreover, by Western blot an increase in SEPP1 expression was observed after hypoxic injury as after adding sodium selenite. Conclusions: Our preliminary results shed light on the possible role of selenium supplementation as a means to prevent oxidative damage and to increase SEPP1 after acute kidney injury. In our in vitro model, SEPP1 emerges as a promising biomarker of kidney injury, although further studies in vivo are necessary to validate our findings.

Enhancing Selenium Accumulation in Rhodotorula mucilaginosa Strain 6S Using a Proteomic Approach for Aquafeed Development.

It is known that selenium (Se) is an essential trace element, important for the growth and other biological functions of fish. One of its most important functions is to contribute to the preservation of certain biological components, such as DNA, proteins, and lipids, providing protection against free radicals resulting from normal metabolism. The objective of this study was to evaluate and optimize selenium accumulation in the native yeast Rhodotorula mucilaginosa 6S. Sodium selenite was evaluated at different concentrations (5-10-15-20-30-40 mg/L). Similarly, the effects of different concentrations of nitrogen sources and pH on cell growth and selenium accumulation in the yeast were analyzed. Subsequently, the best cultivation conditions were scaled up to a 2 L reactor with constant aeration, and the proteome of the yeast cultured with and without sodium selenite was evaluated. The optimal conditions for biomass generation and selenium accumulation were found with ammonium chloride and pH 5.5. Incorporating sodium selenite (30 mg/L) during the exponential phase in the bioreactor after 72 h of cultivation resulted in 10 g/L of biomass, with 0.25 mg total Se/g biomass, composed of 25% proteins, 15% lipids, and 0.850 mg total carotenoids/g biomass. The analysis of the proteomes associated with yeast cultivation with and without selenium revealed a total of 1871 proteins. The results obtained showed that the dynamic changes in the proteome, in response to selenium in the experimental medium, are directly related to catalytic activity and oxidoreductase activity in the yeast. R. mucilaginosa 6S could be an alternative for the generation of selenium-rich biomass with a composition of other nutritional compounds also of interest in aquaculture, such as proteins, lipids, and pigments.

Paracoccus benzoatiresistens sp. nov., a benzoate resistance and selenite reduction bacterium isolated from wetland.

A Gram-stain-negative, aerobic, non-motile, catalase- and oxidase-positive, pale orange, rod-shaped strain EF6T, was isolated from a natural wetland reserve in Hebei province, China. The strain grew at 25-37 °C (optimum, 30 °C), pH 5-9 (optimum, pH 7), and in the presence of 1.0-4.0% (w/v) NaCl (optimum, 2%). A phylogenetic analysis based on 16S rRNA gene sequence revealed that strain EF6T belongs to the genus Paracoccus, and the closest members were Paracoccus shandongensis wg2T with 98.1% similarity, Paracoccus fontiphilus MVW-1 T (97.9%), Paracoccus everestensis S8-55 T (97.7%), Paracoccus subflavus GY0581T (97.6%), Paracoccus sediminis CMB17T (97.3%), Paracoccus caeni MJ17T (97.0%), and Paracoccus angustae E6T (97.0%). The genome size of strain EF6T was 4.88 Mb, and the DNA G + C content was 65.3%. The digital DNA-DNA hybridization, average nucleotide identity, and average amino acid identity values between strain EF6T and the reference strains were all below the threshold limit for species delineation (< 32.8%, < 88.0%, and < 86.7%, respectively). The major fatty acids (≥ 5.0%) were summed feature 8 (86.3%, C18:1 ω6c and/or C18:1 ω7c) and C18:1 (5.0%) and the only isoprenoid quinone was Q-10. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, two unidentified glycolipids, five unidentified phospholipids, and an unidentified aminolipid. Strain EF6T displays notable resistance to benzoate and selenite, with higher tolerance levels (25 g/L for benzoate and 150 mM for selenite) compared to the closely related species. Genomic analysis identified six benzoate resistance genes (acdA, pcaF, fadA, pcaC, purB, and catA) and twenty selenite resistance and reduction-related genes (iscR, ssuB, ssuD, selA, selD and so on). Additionally, EF6T possesses unique genes (catA, ssuB, and ssuC) absent in the closely related species for benzoate and selenite resistance. Its robust resistance to benzoate and selenite, coupled with its genomic makeup, make EF6T a promising candidate for the remediation of both organic and inorganic pollutants. It is worth noting that the specific resistance phenotypes described above were not reported in other novel species in Paracoccus. Based on the results of biochemical, physiological, phylogenetic, and chemotaxonomic analyses, combined with comparisons of the 16S rRNA gene sequence and the whole genome sequence, strain EF6T is considered to represent a novel species of the genus Paracoccus within the family Rhodobacteraceae, for which the name Paracoccus benzoatiresistens sp. nov. is proposed. The type strain is EF6T (= GDMCC 1.3400 T = JCM 35642 T = MCCC 1K08702T).

Response surface methodology optimizes selenium inhibition of prostate cancer PC-3 cell viability.

BACKGROUND: The rising incidence of prostate cancer in the U.S. necessitates innovative therapeutic approaches to this disease. Though extensive research has studied Selenium as an anticarcinogen against prostate cancer, results have varied due to overlooked experimental confounds. Recent studies have identified differential effects of various selenium compounds on prostate cancer cells. This study leverages Mixture Design Response Surface Methodology to characterize the ideal combination of select Se forms against the PC-3 prostate cancer cell line. METHODS: The PC-3 cell line was chosen as a model for its representation of advanced-stage malignancy. Three Se compounds-sodium selenite, methylseleninic acid, and nano-selenium-were selected for their promising antineoplastic potential. Nano-Se particles were synthesized and subsequently characterized by transmission electron microscopy. Cells were cultured, treated with Se compounds, and assessed for viability using an Alamar Blue Assay. IC50 values of individual Se compounds were determined, and treatment combinations evaluated. In collaboration with statical modeling experts, MDRSM was utilized to optimize Se compound combinations. RESULTS: Absolute IC50 values were identified for methylseleninic acid (5.01 µmol/L), sodium selenite (13.8 µmol/L), and nano-selenium (14.6 µmol/L). Combining methylseleninic acid and sodium selenite resulted in only 5% PC-3 cell viability, whereas individual treatments reduced viability by approximately 45%. Among the tested mixtures, the 50:50 combination of MSA and sodium selenite most effectively decreased PC-3 cell viability. Regression analysis indicated the special cubic model had a strong fit (multiple r² = 0.9853), predicting maximum cell viability reduction from the methylseleninic acid and selenite mixture. CONCLUSION: The specific form of Selenium plays a pivotal role in determining its physiological effects and therapeutic potential against prostate cancer. All three selenium compounds showed variable antineoplastic effects, with a 50:50 mixture of methylseleninic acid and selenite exhibiting optimal results. Nano-selenium, when combined with selenite, showed no additive effect, implying a shared mechanism of action. Our research underscores the critical need to consider Se compound forms as distinct entities in prostate cancer treatment and encourages further exploration of Se compounds against prostate cancer.

Effects of replacing Na selenite in laying hen feed with selenized glucose on production performance, egg quality, egg selenium content, microbial population, immunological response, antioxidant enzymes, and fatty acid composition.

This study aimed to explore the effects of selenized glucose (SeGlu) and Na selenite supplementation on various aspects of laying hens such as production performance, egg quality, egg Se concentration, microbial population, antioxidant enzymes activity, immunological response, and yolk fatty acid profile. Using a 2 × 2 factorial design, 168 laying hens at 27-wk of age were randomly divided into 4 treatment groups with 7 replications. Se source (Na selenite and SeGlu) and Se level (0.3 and 0.6 mg/kg) were used as treatments. When 0.3 mg SeGlu/kg was compared to 0.3 mg Na selenite/kg, the interaction findings revealed that 0.3 mg SeGlu/kg increased egg production percent and shell ash (P < 0.05). When compared to 0.3 mg Na selenite/kg, dietary supplementation with 0.3 and 0.6 mg SeGlu/kg resulted in an increase in albumen height, Haugh unit, and yolk color of fresh eggs (P < 0.05). SeGlu enhanced albumen height, Haugh unit, shell thickness (P < 0.01), albumen index, yolk share, specific gravity, shell ash (P < 0.05) of fresh eggs and shell thickness (P < 0.05) of stored eggs as compared to Na selenite. The interaction showed that 0.6 mg SeGlu/kg enhanced yolk Se concentration while decreasing malondialdehyde levels in fresh egg yolk (P < 0.05). SeGlu enhanced Se concentration in albumen and glutathione peroxidase activity in plasma (P < 0.05) as compared to Na selenite. 0.6 mg Se/kg increased lactic acid bacteria, antibody response to sheep red blood cells, and lowered ∑n-6 PUFA/ ∑n-3 PUFA ratio (P < 0.05). As a result, adding SeGlu to the feed of laying hens enhanced egg production, egg quality, egg Se concentration, fresh yolk lipid oxidation, and glutathione peroxidase enzyme activity.

The actinomycete Kitasatospora sp. SeTe27, subjected to adaptive laboratory evolution (ALE) in the presence of selenite, varies its cellular morphology, redox stability, and tolerance to the toxic oxyanion.

The effects of oxyanions selenite (SeO32-) in soils are of high concern in ecotoxicology and microbiology as they can react with mineral particles and microorganisms. This study investigated the evolution of the actinomycete Kitasatospora sp. SeTe27 in response to selenite. To this aim, we used the Adaptive Laboratory Evolution (ALE) technique, an experimental approach that mimics natural evolution and enhances microbial fitness for specific growth conditions. The original strain (wild type; WT) isolated from uncontaminated soil gave us a unique model system as it has never encountered the oxidative damage generated by the prooxidant nature of selenite. The WT strain exhibited a good basal level of selenite tolerance, although its growth and oxyanion removal capacity were limited compared to other environmental isolates. Based on these premises, the WT and the ALE strains, the latter isolated at the end of the laboratory evolution procedure, were compared. While both bacterial strains had similar fatty acid profiles, only WT cells exhibited hyphae aggregation and extensively produced membrane-like vesicles when grown in the presence of selenite (challenged conditions). Conversely, ALE selenite-grown cells showed morphological adaptation responses similar to the WT strain under unchallenged conditions, demonstrating the ALE strain improved resilience against selenite toxicity. Whole-genome sequencing revealed specific missense mutations in genes associated with anion transport and primary and secondary metabolisms in the ALE variant. These results were interpreted to show that some energy-demanding processes are attenuated in the ALE strain, prioritizing selenite bioprocessing to guarantee cell survival in the presence of selenite. The present study indicates some crucial points for adapting Kitasatospora sp. SeTe27 to selenite oxidative stress to best deal with selenium pollution. Moreover, the importance of exploring non-conventional bacterial genera, like Kitasatospora, for biotechnological applications is emphasized.

Effects of sodium selenite, yeast selenium, and nano-selenium on toxicity, growth, and selenium bioaccumulation in Lucilia sericata maggots.

In this study, we investigated the effects of different types of selenium (Se) (sodium selenite [SS], yeast selenium [YS], and nano-selenium [NS]) on the toxicity, growth, Se accumulation, and transformation of Lucilia sericata maggots (LSMs). We found that the 50% lethal concentration of LSMs exposed to SS was 2.18 and 1.96 times that of YS and NS, respectively. LSM growth was significantly promoted at exposure concentrations of 10-50 mg kg-1 in group SS and 10-30 mg kg-1 in group YS, whereas NS inhibited LSMs growth at all concentrations (p < 0.05). Total Se content in LSMs, conversion efficiency to organic and other forms of Se, and bioaccumulation factor of Se were the highest in the SS group when exposed to 50 mg kg-1 (81.6 mg kg-1, 94.6%, and 1.63, respectively). Transcriptomic results revealed that LSMs significantly upregulated the amino acid (alanine, aspartate, glutamic, and tyrosine) and tricarboxylic acid cycle signaling pathways (p < 0.05) on exposure to Se, resulting in a significant increase in LSMs biomass and quality. In conclusion, our study indicates that LSMs exhibit good tolerance to SS and can convert it into bioorganic or other forms of Se.

Study of selenium enrichment metabolomics in Bacillus subtilis BSN313 via transcriptome analysis.

In this study, the transcriptome analysis was practiced to identify potential genes of probiotic Bacillus subtilis BSN313 involved in selenium (Se) enrichment metabolism. The transcriptomic variation of the strain was deliberated in presence of three different sodium selenite concentrations (0, 3, and 20 µg/mL). The samples were taken at 1 and 13 h subsequent to inoculation of selenite and gene expression profiles in Se metabolism were analyzed through RNA sequencing. The gene expression levels of the pre log phase were lower than the stationary phase. It is because, the bacteria has maximum grown with high concentration of Se (enriched with organic Se), at stationary phase. Bacterial culture containing 3 µg/mL concentration of inorganic Se (sodium selenite) has shown highest gene expression as compared to no or high concentration of Se. This concentration (3 µg/mL) of sodium selenite (as Se) in the medium promoted the upregulation of thioredoxin reductase expression, whereas its higher Se concentration inhibited the formation of selenomethionine (SeMet). The result of 5 L bioreactor fermentation showed that SeMet was also detected in the fermentation supernatant as the growth entered in the late stationary phase and reached up to 857.3 ng/mL. The overall intracellular SeMet enriched content in BSN313 was extended up to 23.4 µg/g dry cell weight. The other two selenoamino acids (Se-AAs), methyl-selenocysteine, and selenocysteine were hardly detected in medium supernatant. From this study, it was concluded that SeMet was the highest content of organic Se byproduct biosynthesized by B. subtilis BSN313 strain in Se-enriched medium during stationary phase. Thus, B. subtilis BSN313 can be considered a commercial probiotic strain that can be used in the food and pharmaceutical industries. This is because it can meet the commercial demand for Se-AAs (SeMet) in both industries.

Superoxide Dismutase Catalyzed Size-Adjustable Selenium Nanoparticles in Saccharomyces boulardii.

Selenium nanoparticles (SeNPs) are important and safe food and feed additives that can be used for dietary supplementation. In this study, a mutagenic strain of Saccharomyces boulardii was employed to obtain biologically synthesized SeNPs (BioSeNPs) with the desired particle size by controlling the dosage and duration of sodium selenite addition, and the average particle size achieved was 55.8 nm with protease A encapsulation. Transcriptomic analysis revealed that increased expression of superoxide dismutase 1 (SOD1) in the mutant strain effectively promoted the synthesis of BioSeNPs and the formation of smaller nanoparticles. Under sodium selenite stress, the mutant strain exhibited significantly increased expression of glutathione peroxidase 2 (GPx2), which was significantly greater in the mutant strain than in the wild type, facilitating the synthesis of glutathione selenol and providing abundant substrates for the production of BioSeNPs. Furthermore, based on the experimental results and transcriptomic analysis of relevant genes such as sod1, gpx2, the thioredoxin reductase 1 gene (trr1) and the thioredoxin reductase 2 gene (trr2), a yeast model for the size-controlled synthesis of BioSeNPs was constructed. This study provides an important theoretical and practical foundation for the green synthesis of controllable-sized BioSeNPs or other metal nanoparticles with potential applications in the fields of food, feed, and biomedicine.

Protecting spring wheat plants using selenium and pesticides.

The research was carried out in order to find ways to optimize the system of protection of spring wheat crops. In the conducted studies, the effect of combinations of sodium selenite and various pesticides, differing in the specifics of action and biological activity, on the yield and quality of spring wheat of the Yubileinaya 80 variety was studied. Currently, there is a need to achieve a sufficient effect of the action of chemical plant protection products and to obtain a minimum impact on human health and the environment. The purpose of the research is to study the influence of various combinations of chemical plant protection products and methods of using sodium selenite on the yield and grain quality indicators of spring wheat variety Yubileinaya 80. The studies were carried out under the conditions of a vegetative experiment with spring wheat variety Yubileinaya 80. Two methods of using sodium selenite and chemical plant protection agents of different specifics of action were studied: fungicide, herbicide, and insecticide, which were applied in different combinations and at different times. As a result of the studies, the phytotoxicity of the studied preparations of chemical plant protection was revealed, which apparently manifests itself as a result of inhibition of the morphometric indicators of the growth of the root system and vegetative organs of wheat plants, resulting in a violation of the processes of accumulation of assimilates and their outflow to the reproductive organs. Optimal combinations of pesticides and sodium selenite have been established, allowing to obtain reliable changes in yield and quality indicators of wheat grain. It was revealed that the use of selenium treatment before sowing seeds contributed to a decrease in the phytotoxicity of the studied pesticides, as a result of stimulating the processes of absorption by plants and the redistribution of nitrogen to the reproductive organs of wheat, which had a positive effect not only on the yield and quality of spring wheat of the Yubileynaya 80 variety, but also on the external surface microstructure of the fruit shell of the grain. The noted features of the surface of the fruit shell of the grain will reduce losses during grain processing and obtain processed products from such grain of higher quality.

Effects of sodium selenite, cysteamine, bacterially synthesized Se-NPs, and cysteamine loaded on Se-NPs on ram sperm cryopreservation.

During the cryopreservation of sperm, the production of highly reactive oxygen species (ROS) can reduce their viability and fertility. However, the addition of antioxidants can help reduce the harmful effects of ROS. One such antioxidant is selenium, which is a co-factor of the glutathione peroxidase enzyme that is effective in scavenging ROS. Cysteamine can also take part in the structure of this enzyme. The use of nanoparticles can be less toxic to cells than their salt form. To this end, researchers synthesized Se-NPs using the streptococcus bacteria and loaded cysteamine onto the synthesized Se-NPs. The biosynthesis of Se-NPs and cysteamine loaded on Se-NPs was confirmed by UV-visible spectroscopy, X-ray diffraction (EDX), Fourier transforms infrared (FTIR) spectroscopy, and Field Emission Scanning Electron Microscope (FE-SEM). For cryopreservation, ram semen samples were diluted, and different concentrations (0, 1, 5, 25, and 125 µg/mL) of cysteamine, Se-NPs, cysteamine loaded on Se-NPs, and sodium selenite were added. An extender containing no supplement was considered as control group. After cooling the semen samples, they were frozen and stored in liquid nitrogen for evaluation. The samples were thawed and analyzed for mobility, viability, membrane and DNA integrity, and sperm abnormalities, as well as malondialdehyde level (MDA) and superoxide dismutase (SOD). The data was processed using SPSS, and a significance level of p < 0.05 was considered. The results of this experiment showed that adding 1 µg/mL of cysteamine loaded on Se-NPs to the diluent significantly increased the motility, viability, and membrane integrity and SOD of spermatozoa compared to the other treatment groups and control group, and reduced the abnormality, apoptosis, and MDA level of spermatozoa in comparison with the other treatment groups and control group (p < 0.05). In conclusion, the addition of cysteamine loaded on Se-NPs was found to improve the quality of ram sperm after cryopreservation.

Sodium Selenite Prevents Matrine-Induced Nephrotoxicity by Suppressing Ferroptosis via the GSH-GPX4 Antioxidant System.

Matrine (MT), an active ingredient derived from Sophor flavescens Ait, is used as a therapeutic agent to treat liver disease and cancer. However, the serious toxic effects of MT, including nephrotoxicity, have limited its clinical application. Here, we explored the involvement of ferroptosis in MT-induced kidney injury and evaluated the potential efficacy and underlying mechanism of sodium selenite (SS) in attenuating MT-induced nephrotoxicity. We found that MT not only disrupts renal structure in mice but also induces the death of NRK-52E cells. Additionally, MT treatment resulted in significant elevations in ferrous iron, reactive oxygen species (ROS) and lipid peroxidation levels, accompanied by decreases in glutathione (GSH) and glutathione peroxidase (GPx) levels. SS effectively mitigated the alterations in ferroptosis-related indicators caused by MT and prevented MT-induced nephrotoxicity as effectively as Fer-1 in vivo and in vitro. SS also reversed the MT-induced reduction in GPX4, CTH and xCT protein levels. However, the glutathione peroxidase 4 (GPX4) inhibitor RSL3 and knockdown of GPX4, CTH, or xCT via siRNA abolished the protective effect of SS against MT-induced nephrotoxicity, indicating that SS exhibited antiferroptotic effects via the GSH-GPX4 antioxidant system. Overall, MT-induced ferroptosis triggers nephrotoxicity, and SS is a promising therapeutic drug for alleviating MT-induced renal injury by activating the GSH-GPX4 axis.