Hepatoprotective, antioxidant and anti-inflammatory potentials of Vit-E/C@SeNPs in rats: Synthesis, characterization, biochemical, radio-biodistribution, molecular and histopathological studies.

This study aimed to synthesize a nano-structure between selenium, Vit. C, and Vit. E (Vit-E/C@SeNPs) as a promising protective and therapeutic agent for hepatocellular carcinoma. Vit-E/C@SeNPs were characterized using TEM and DLS and its zetapotential was measured to evaluate its stability. DPPH assay and SRB test were performed to estimate its antioxidant capacity and cytotoxicity, respectively. A radiosynthesis of 99mTc-Vit-E/C@SeNPs was done for further in-vivo pharmacokinetic studies on normal and solid tumor induced mice. Further, in-vivo studies were conducted to investigate Vit-E/C@SeNPs efficacy against hepatocellular damage in Wistar albino rats induced by diethylnitrosamine (DEN) / Carbon Tetra chloride (CCl4). The synthesis results showed spherical Vit-E/C@SeNPs with core size of 50 nm, radical scavenging activity (%RSC) of 75.9%, and IC50 of 27.9 µg/ml. The biochemical analysis results showed that the lower liver function biomarker values (ALT, AST, ALP, total bilirubin and GGT) has gone for the Vit-E/C@SeNPs prevention and treated group, which also showed significant depletion of liver tissue l-MDA, and obvious increase in GSH concentration and CAT activity and marked improvement in the histological feature of liver tissue. Additionally, a significant up-regulation of mRNA gene expression levels of inflammatory gene (TGFß1, NFκB, iNOS, PPAR-γ and TNFα) and Apoptotic gene (P53) were determined by using Quantitative real-time PCR (qPCR). The values down regulate and tend to normal in prevention and control group. All of these introduce Vit-E/C@SeNPs as a promising agent as protective and therapeutic agent against DEN/ CCl4-induced hepatocellular damage (Hepatocellular carcinoma).

ROS-Responsive Selenium-Containing Carriers for Coencapsulation of Photosensitizer and Hypoxia-Activated Prodrug and Their Cellular Behaviors.

The integration of hypoxia-activated chemotherapy with photodynamic therapy (PDT) has newly become a potent strategy for tumor treatment. Herein, a reactive oxygen species (ROS)-responsive drug carriers (PS@AQ4N/mPEG-b-PSe NPs) are fabricated based on the amphiphilic selenium-containing methoxy poly(ethylene glycol)-polycarbonate (mPEG-b-PSe), the hydrophobic photosensitizer (PS), and hypoxia-activated prodrug Banoxantrone (AQ4N). The obtained nanoparticles are spherical with an average diameter of 100 nm as characterized by transmission electron microscope (TEM) and dynamic laser scattering (DLS) respectively. The encapsulation efficiency of the PS and AQ4N reaches 92.83% and 51.04% at different conditions, respectively, by UV-vis spectrophotometer. It is found that the drug release is accelerated due to the good ROS responsiveness of mPEG-b-PSe and the cumulative release of AQ4N is up to 89% within 30 h. The cell test demonstrates that the nanoparticles dissociate when triggered by the ROS stimuli in the cancer cells, thus the PS is exposed to more oxygen and the ROS generation efficiency is enhanced accordingly. The consumption of oxygen during PDT leads to the increased tumor hypoxia, and subsequently activates AQ4N into cytotoxic counterpart to inhibit tumor growth. Therefore, the synergistic therapeutic efficacy demonstrates this drug delivery has great potential for antitumor therapy.

Selenium-containing soybean antioxidant peptides: Preparation and comprehensive comparison of different selenium supplements.

Present study aimed to prepare and identify antioxidative peptides from selenium-containing soybeans, and to investigate their bioavailability and protective effects against oxidative stress-related diseases. Selenium-containing soybean antioxidative peptides (Mw < 1 kDa, SePPs) hydrolyzed by Neutrase and Alcalase reached the highest cellular antioxidant activity (EC50 value 320.5 ± 39.71 µg/L). SePPs could be efficiently absorbed through Caco-2 monolayer, and then significantly reverse the tumor necrosis factor-α (TNF-α)-induced inflammatory cytokine, phosphorylated c-Jun N-terminal kinases (p-JNK) and nuclear factor-kappa B (NF-κB) levels in EA. hy926 cells (p < 0.05). d-galactose-induced aging mice model showed that liver superoxidase dismutase (SOD) and glutathione peroxidase-1 (GPx-1) were enhanced, while aspartate aminotransferase (AST), alanine aminotransferase (ALT) and NF-κB were decreased by SePPs significantly (p < 0.05). SePPs could inhibit brain oxidative stress via regulating MAPK/NF-κB pathway. Comparing with Na2SeO3, selenomethionine (SeMet) and selenium-free peptides, SePPs was found to present synergistic effects of selenium and peptides in antioxidant activity.

Selenium Nanocomposites in Natural Matrices as Potato Recovery Agent.

The paper presents a study of the effect of chemically synthesized selenium nanocomposites (Se NCs) in natural polymer matrices arabinogalactan (AG) and starch (ST) on the viability of the potato ring rot pathogen Clavibacter sepedonicus (Cms), potato plants in vitro, and the soil bacterium Rhodococcus erythropolis. It was found that the studied Se NCs have an antibacterial effect against the phytopathogenic Cms, reducing its growth rate and ability to form biofilms. It was revealed that Se NC based on AG (Se/AG NC) stimulated the growth and development of potato plants in vitro as well as their root formation. At the same time, Se did not accumulate in potato tissues after the treatment of plants with Se NCs. The safety of the Se NCs was also confirmed by the absence of a negative effect on the growth and biofilm formation of the soil bacterium R. erythropolis. The obtained results indicate that Se NCs are promising environmentally safe agents for the protection and recovery of cultivated plants from phytopathogenic bacteria.

Selenium source and level on performance, selenium retention and biochemical responses of young broiler chicks.

BACKGROUND: Selenium (Se) has been recognized as an essential micronutrient for nearly all forms of life. In recent decades, broiler responses to dietary Se supplemental levels and sources have received considerable attention. On environmental grounds, organic trace mineral utilization in practical broiler feeds has been defended due to its higher bioavailability. In such feeds, trace minerals are provided simultaneously in the same supplement as inorganic salts or organic chelates, a fact commonly ignored in assays conducted to validate organic trace mineral sources. The current assay aimed to investigate growth and biochemical responses, as well as Se retention of growing chicks fed diets supplemented with organic and inorganic Se levels and where the trace minerals (zinc, copper, manganese, and iron) were provided as organic chelates or inorganic salts according to Se source assessed. In so doing, a 2 × 5 factorial arrangement was used to investigate the effects of sodium selenite (SS) and selenium-yeast (SY) supplemented in feeds to provide the levels of 0, 0.08, 0.16, 0.24, and 0.32 mg Se/kg. RESULTS: Chicks fed selenium-yeast diets had body weight (BW), and average daily gain (ADG) maximized at 0.133 and 0.130 mg Se/kg, respectively. Both Se sources linearly increased (P < 0.05) the glutathione peroxidase (GSH-Px) activity in chick blood but higher values were observed in sodium selenite fed chicks (P < 0.05). Both Se sources influenced thyroid hormone serum concentrations (P < 0.05). Chicks fed SY exhibited greater retention of Se in the feathers (P < 0.05). Relative bioavailability of selenium yeast compared with SS for the Se content in carcass, feathers, total and Se retention were, 126, 116, 125 and 125%, respectively. SY supplementation resulted in lower liver Se concentration as Se supplementation increased (P < 0.05). CONCLUSIONS: Based on performance traits, the supplemental level of organic Se as SY in organic trace minerals supplement to support the maximal growth of broiler chicks is 0.133 mg Se/kg.

Selenium nanoparticles coated with pH responsive silk fibroin complex for fingolimod release and enhanced targeting in thyroid cancer.

Cancer-targeted drug delivery systems based on nanoparticles (NPs) have been considered promising therapies. In this study, we developed a pH-responsive smart NPs drug delivery system using silk fibroin (SF), selenium nanoparticles (Se NPs), fingolimod (FTY720), and heptapeptide (T7). The prepared FTY720@T7-SF-Se NPs were spheres with an average diameter of 120 nm, which would contribute to the enhanced permeability and retention effects in tumour regions. The encapsulation efficiency (EE) of the FTY720@T7-SF-Se NPs was 71.95 ± 3.81%. The release of FTY720 from the nanocarriers was pH-dependent, and the release of FTY720 was accelerated in an acidic environment. Both in vitro and in vivo studies showed that FTY720@T7-SF-Se NPs had an enhanced cellular uptake selectivity and antitumor activity for thyroid cancer. The bio-distribution study in vivo further demonstrated that FTY720@T7-SF-Se NPs could effectively accumulate in the tumour region, thereby enhancing the ability to kill cancer cells in vivo. In addition, studies of histology and immunohistochemistry showed that FTY720@T7-SF-Se NPs had low toxicity to the major organs of tumour-bearing mice, indicating the prepared NPs has good biocompatibility in vivo. These results suggest that the tumour-targeted NPs delivery system (FTY720@T7-SF-Se NPs) has great potential as a new tool for thyroid cancer therapy.

Selenium accumulation in protein fractions of Tenebrio molitor larvae and the antioxidant and immunoregulatory activity of protein hydrolysates.

Although numerous types of organisms have been used to enrich selenium, a low-cost and efficient organism is yet to be identified. This study aimed to develop a new means of selenium enrichment using Tenebrio molitor larvae. Our results indicated that the total selenium content in larvae was increased 83-fold to 54.21 ± 1.25 µg/g, and of this content, organic selenium accounted for over 97% after feeding the larvae with 20 µg/g of sodium selenite. Selenium was distributed unequally in the protein fraction with following order: alkali-soluble protein-bound selenium (36.32%) > salt-soluble protein-bound selenium (19.41%) > water-soluble protein-bound selenium (17.03%) > alcohol-soluble protein-bound selenium (3.21%). Additionally, 81% of the selenium within the soluble proteins was distributed in subunits possessing molecular weights of <40 kDa. After hydrolysis by alcalase, the protein hydrolysate of selenium-enriched larvae possessing 75% selenium recovery exhibited stronger antioxidant and immunoregulatory activities than those of regular larvae.

Supplementation of nano-selenium in fish diet: Impact on selenium assimilation and immune-regulated selenoproteome expression in monosex Nile tilapia (Oreochromis niloticus).

Selenium (Se), a fundamental element of nutrigenomic science in fish nutrition, was used to investigate its impact on selenoproteome expression and Se regulation in tilapia. Different concentrations (T1 - 0, T2 - 0.5, T3 - 1.0 and T4 - 2.0 mg/kg of feed) of dietary nano-Se were incorporated in the diets of monosex Nile tilapia. A total of 180 tilapia fingerlings with initial weight (15.73 ± 0.05 g) were stocked in 150 L capacity FRP tanks categorized into four diet groups with triplicate each for a feeding trial of 90 days. At the end of first, second and third months of the feeding trial, gill, liver, kidney and muscle tissues were harvested to evaluate the effect on the kinetics of Se bioaccumulation and assimilation as well as immune-regulated selenoprotein transcripts (GPx2, SelJ, SelL, SelK, SelS, SelW and Sepp1a) and their synthesis factors (SPS1 and Scly). The findings depicted that significantly (p < 0.05) higher weight gain was found in the diet supplemented with 1.0 mg/kg of nano-Se. The theory of second-order polynomial regression supported the same. The liver showed significantly (p < 0.05) higher Se accumulation and concentration factor among the harvested tissues in a different timeline. All the selected immune-regulated selenoproteins and synthesis factors in different fish tissues showed significantly (p < 0.05) up-regulation in the diet supplemented with 1.0 mg/kg of nano-Se for the second month. Therefore, the present findings suggested that the supplementation of nano-Se could be more effective for improved growth, better selenium regulation and expression of immune-regulated selenoproteins in the fish model.

Pharmaconutrition revisited for critically ill patients with coronavirus disease 2019 (COVID-19): Does selenium have a place?

Coronavirus disease 2019 (COVID-19) is a global pandemic causing one of the biggest challenges for critical care medicine. Mortality from COVID-19 is much greater in elderly men, many of whom succumb to acute respiratory distress syndrome (ARDS) triggered by the viral infection. Because there is no specific antiviral treatment against COVID-19, new strategies are urgently needed. Selenium is an essential trace element with antioxidant and immunomodulatory effects. Poor nutritional status increases the pathogenicity of viruses and low selenium in particular can be a determinant of viral virulence. In the past decade, selenium pharmaconutrition studies have demonstrated some reduction in overall mortality, including how reduced incidence of ventilator-associated pneumonia and infectious complications such as ARDS in the critically ill. Consequently, we postulate that intravenous selenium therapy, could be part of the therapeutic fight against COVID-19 in intensive care unit patients with ARDS and that outcomes could be affected by age, sex, and body weight. Our working hypothesis addresses the question: Could high-dose selenite pharmaconutrition, as an early pharmacologic intervention, be effective at reducing the incidence and the progression from type 1 respiratory failure (non-ARDS) to severe ARDS, multiorgan failure, and new infectious complications in patients with COVID-19 patients?

Phytoglycogen Nanoparticle Delivery System for Inorganic Selenium Reduces Cytotoxicity without Impairing Selenium Bioavailability.

PURPOSE: Selenium is an essential trace element that supports animal health through the antioxidant defense system by protecting cells from oxidative-related damage. Using inorganic selenium species, such as sodium selenite (Na Sel), as a food supplement is cost-effective; however, its limitation as a nutritional supplement is its cytotoxicity. One strategy to mitigate this problem is by delivering inorganic selenium using a nanoparticle delivery system (SeNP). METHODS: Rainbow trout intestinal epithelial cells, bovine turbinate cells and bovine intestinal myofibroblasts were treated with soluble Na Sel or SeNPs. Two SeNP formulations were tested; SeNP-Ionic where inorganic selenium was ionically bound to cationic phytoglycogen (PhG) NPs, and SeNP-Covalent, where inorganic selenium was covalently bound to PhG NPs. Selenium-induced cytotoxicity along with selenium bioavailability were measured. RESULTS: SeNPs (SeNP-Ionic or SeNP-Covalent) substantially reduced cytotoxicity in all cell types examined compared to similar doses of soluble inorganic selenium. The SeNP formulations did not affect selenium bioavailability, as selenium-induced glutathione peroxidase (GPx) activity and GPx1 transcript levels were similarly elevated whether cells were treated with soluble Na Sel or SeNPs. This was the case for all three cell types tested. CONCLUSION: Nanoparticle-assisted inorganic selenium delivery, which demonstrated equal bioavailability without causing deleterious cytotoxic side effects, has potential applications for safely supplementing animal diets with inorganic selenium at what are usually toxic doses.

Synthesis and comparative assessment of antiradical activity, toxicity, and biodistribution of κ-carrageenan-capped selenium nanoparticles of different size: in vivo and in vitro study.

In the present study, water-soluble hybrid selenium-containing nanocomposites have been synthesised via soft oxidation of selenide-anions, preliminarily generated from elemental bulk-selenium in the base-reduction system 'N2H4-NaOH'. The nanocomposites obtained consist of Se0NPs (4.6-24.5 nm) stabilised by κ-carrageenan biocompatible polysaccharide. The structure of these composite nanomaterials has been proven using complementary physical-chemical methods: X-ray diffraction analysis, transmission electron microscopy, optical spectroscopy, and dynamic light scattering. Optical ranges of 'emission/excitation' of aqueous solutions of nanocomposites with Se0NPs of different sizes are established and the most important parameters of their luminescence are determined. For the obtained nanocomposites, the expressed antiradical activity against free radicals 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid has been found, the value of which depends on the size of selenium nanoparticles. It is experimentally revealed that all obtained nanocomposites are low toxic (LD50 >2000 mg/kg). It is also found that small selenium nanoparticles (6.8 nm), in contrast to larger nanoparticles (24.5 nm), are accumulated in organisms to significantly increase the level of selenium in the liver, kidneys, and brain (in lesser amounts) of rats.

Uptake, translocation and biotransformation of selenium nanoparticles in rice seedlings (Oryza sativa L.).

BACKGROUND: Selenium (Se) in soil mainly consists of selenite, selenate, and elemental Se. However, little is known about the mechanism involved in the uptake and biotransformation of elemental Se by plants. RESULTS: In this study, the uptake, translocation, subcellular distribution and biotransformation of selenium nanoparticles (SeNPs) in rice (Oryza sativa L.), and a comparison with selenite and selenate, were investigated through hydroponic experiments. The study revealed that SeNPs could be absorbed by rice plants; and aquaporin inhibitor was responsible for a 60.4% inhibition of SeNP influx, while metabolic inhibitor was ineffective. However, the SeNPs uptake rate of rice roots was approximately 1.7 times slower than that of selenite or selenate. Under the SeNPs or selenite treatment, Se was primarily accumulated in roots rather than in shoots, whereas an opposite trend was observed with selenate treatment. Additionally, most of the absorbed Se was distributed in cell wall of the SeNPs or selenite treated-rice plants, while its proportion was the highest in soluble cytosol of the selenate treated-rice plants. The absorbed SeNPs or selenite was rapidly assimilated to organic forms, with SeMet being the most predominant species in both shoots and roots of the rice plants. However, following selenate treatment, Se(VI) remained as the most predominant species, and only a small amount of it was converted to organic forms. CONCLUSION: Therefore, this study provides a deeper understanding of the mechanisms associated SeNPs uptake and biotransformation within plants.

Effects of Dietary Supplements on the Bioaccessibility of Se, Zn and Cd in Rice: Preliminary Observations from In Vitro Gastrointestinal Simulation Tests.

Trace elements such as selenium (Se) and zinc (Zn) are essential elements in the human body, while cadmium (Cd) has no physiological function. A high proportion of people consume dietary supplements to enhance the performance of the body or alter the nutrient contents within the body. Therefore, this study was conducted to evaluate the interaction effects of several popular dietary supplements on the bioaccessibility of Se, Zn and Cd in rice with the hope of identifying dietary supplements that can increase rice Se and Zn bioaccessibility but decrease rice Cd bioaccessibility. The results from in vitro gastrointestinal simulation tests showed that the bioaccessibility of these elements in rice was in the order of Cd (52.07%) > Zn (36.63%) > Se (10.19%) during the gastric phase and Zn (26.82%) > Cd (18.72%) > Se (14.70%) during the intestinal phase. The bioaccessibility of Se during the intestinal phase was greater than that during the gastric phase, and the bioaccessibility of Zn and Cd were the opposite. The bioaccessibility of Se significantly increased in response to vitamin C (VC), vitamin E (VE), vitamin B6 (VB6) and vitamin B9 (VB9), especially VC, which also increased the bioaccessibility of Zn and decreased that of Cd. Procyanidins (OPC), methionine (Met) and coenzyme Q10 (Q10) significantly reduced the bioaccessibility of Se. These results suggest that the reasonable use of dietary supplements can effectively regulate the in vivo contents of trace elements, which provide valuable information for developing health interventions to address problems for specific people, especially selenium-deficient people.

Selenium biofortification in Hericium erinaceus (Lion's Mane mushroom) and its in vitro bioaccessibility.

Hericium erinaceus is a traditional edible mushroom. Selenium (Se) is an essential trace element for humans and other mammals. To develop a Se biofortification strategy for H. erinaceus, the effects of selenate, selenite, and selenomethionine (SeMet) on Se uptake and mushroom growth were investigated. Selenium bioaccessibility and the major Se species present in Se-enriched H. erinaceus were tested in vitro . The H. erinaceus growth was efficiently affected by SeMet than by selenite and selenate. Selenium concentrations in fruiting bodies increased with substrate Se concentration and disturbed accumulation of other microelements. Substrate Se was absorbed and transformed into organic forms. The major Se species in Se-enriched fruiting bodies was SeMet (>63.9%). During in vitro gastrointestinal digestion tests, 51% of total Se was released, and selenocystine (SeCys2 ) (90%) and Se-methylselenocysteine (MeSeCys) (76%) were more easily digested than SeMet (51%). H. erinaceus is suggested as a novel dietary source of supplemental bioavailable Se.

Physicochemical and functional properties of chitosan-stabilized selenium nanoparticles under different processing treatments.

Selenium nanoparticles (Se0NPs) have been well-characterized; however, whether processing affects their physicochemical and functional properties remains unknown. Here, chitosan (low and high molecular weight; CS(L) and CS(H), respectively) was used to stabilize Se0NPs, and the effects of heating (37 â„ƒ, 70 â„ƒ, and 95 â„ƒ), freeze-drying-rehydration, and freeze-thawing on CS-Se0NPs physicochemical stability, Se release, antioxidant capacity, and antibacterial activity were evaluated. The results demonstrated that all treatments could cause CS-Se0NPs aggregation and Se release to varying degrees. Aggregation of CS-Se0NPs decreased their antibacterial activity, while Se release increased their antioxidant capacity with negligible effects on antibacterial activities. None of the CS-Se0NPs could tolerate freeze-thawing. CS(H)-Se0NPs exhibited better rehydration and heating stability than CS(L)-Se0NPs, although "rod-like" triclinic crystalline Se in CS(H)-Se0NPs, produced by 95℃ heating, decreased both antioxidant and antibacterial activities. Thus, these results provide a theoretical basis for the development and suitable application of CS-Se0NPs.

Exhibiting the diagnostic face of selenium nanoparticles as a radio-platform for tumor imaging.

Selenium nanoparticles (SeNPs) have become one of the most prospective and promising tools in the course of cancer diagnosis and therapy. Here we describe the synthesis of a novel radioactive platform for tumor imaging using selenium nanoparticles. SeNPs were synthetized using dithionite and glutathione as reducing and capping agent respectively with 5 mmol/L sodium selenite as a precursor and then SeNPs radiolabeled with technetium-99 m, the most common and famous radioactive isotope used for imaging purposes. A characteristic profile for the synthesized SeNPs was performed including size analysis, zeta potential, antioxidant activity, radiochemical yield and in-vivo biodistribution in normal and solid tumor bearing mice. Size analysis showed amorphous SeNP cores of a mean diameter of 21 ± 5 nm with a hydrodynamic size of 43 ± 8 nm and -28 mV zeta potential. The particles also showed a superior antioxidant activity of radical scavenging activity 55.6% according to DPPH assay, in addition, satisfying radiochemical yield up to 97 ± 1.5 was achieved. In vivo studies were applied on male Swiss albino mice that demonstrated a good biodistribution pattern in normal mice with a moderate accumulation in liver at 30 min post injection. Excellent T/NT ratios were obtained in solid tumor bearing mice throughout the experimental time points. The as-synthetized selenium nanoparticles demonstrated surprising and satisfying features which make them promising enough for tumor theranosis.

Selenium biofortified alfalfa hay fed in low quantities improves selenium status and glutathione peroxidase activity in transition dairy cows and their calves.

The hypothesis of the study was that feeding a relatively low amount of Se biofortified alfalfa hay during the dry period and early lactation would improve selenium status and glutathione peroxidase activity in dairy cows and their calves. Ten Jersey and 8 Holstein primiparous dairy cows were supplemented with Se biofortified (TRT; n = 9) or non-biofortified (CTR; n = 9) alfalfa hay at a rate of 1 kg/100 kg of BW mixed with the TMR from 40 d prior parturition to 2 weeks post-partum. Se concentration in whole blood, liver, milk, and colostrum, the transfer of Se to calves, and the glutathione peroxidase (GPx) activity were assessed. TRT had 2-fold larger (P < 0.05) Se in blood v. CTR that resulted in larger Se in liver and colostrum but not milk and larger GPx activity in plasma and erythrocytes but not in milk. Compared to CTR, calves from TRT had larger Se in blood but only a numerical (P = 0.09) larger GPx activity in plasma. A positive correlation was detected between Se in the blood and GPx activity in erythrocytes and plasma in cows. Our results demonstrated that feeding pregnant primiparous dairy cows with a relatively low amount of Se-biofortified alfalfa hay is an effective way to increase Se in the blood and liver, leading to greater antioxidant activity via GPx. The same treatment was effective in improving Se concentration in calves but had a modest effect on their GPx activity. Feeding Se biofortified hay increased Se concentration in colostrum but not in milk.

Selenium Nanoparticles-Embedded Chitosan Microspheres and Their Effects Upon Alcohol-Induced Gastric Mucosal Injury in Rats: Rapid Preparation, Oral Delivery, and Gastroprotective Potential of Selenium Nanoparticles.

BACKGROUND: Selenium (Se) is an indispensable trace element required for animals and human beings, whereas Se-deficiency can accelerate the development of acute gastric injury induced by over-consumption of alcohol. Selenium nanoparticles (SeNPs), as a special Se-supplement with favorable properties and unique bioactivities, are expected to play a passive role in gastroprotection. To the best of our knowledge, the gastroprotective potential of SeNPs is unknown and also, a rapid preparation of orally stable SeNPs available for prospective commercial application in the clinic is needed. Thus, SeNPs-embedded chitosan microspheres (SeNPs-CM) were developed to deliver SeNPs, and their gastroprotective potential was evaluated. RESULTS: Herein, a rapid, eco-friendly and economic preparation process, composed of synthesis of SeNPs decorated by chitosan (CS), purification of CS-SeNPs by ultra-filtration (UF) and spray-drying of the purified CS-SeNPs, was introduced to prepare SeNPs-CM. The uniformly distributed SeNPs with a nanosize range of 60 nm were loaded into CS-microspheres, and they could be released from the microspheres in gastric conditions. In addition, SeNPs-CM were safer than selenite in terms of Se dose, with a LD50 of around 8-fold of that of selenite, and it could efficiently enhance the Se retention in Se-deficient Wistar rats. Furthermore, SeNPs-CM pre-treatment might significantly attenuate the ethanol-induced gastric mucosal damage, based on histological evaluation. It might be partly attributed to the systematic antioxidant activities of SeNPs-CM, reflected by the reduction in lipid peroxidation, the augmentation in antioxidant enzymatic activity as well as decreasing aggressive nitric oxides (NO). CONCLUSION: SeNPs-CM could be taken into consideration as a prospective Se-supplement for the oral delivery of SeNPs, with prominent gastroprotective effect against ethanol-induced mucosal injury.

Safe utilization and zoning on natural selenium-rich land resources: a case study of the typical area in Enshi County, China.

Selenium (Se) is an essential trace element. However, Se in soil is often accompanied by heavy metals, such as cadmium (Cd), because of geological background. The safe utilization of such Se-rich land resources remains a challenge. A typical Se-rich area located in Enshi County, China, was systematically investigated with geochemical and epidemiological methods. The results show that Se in the topsoil is 0.84 ± 1.39 µg/g, whereas that of Cd is 0.93 ± 1.63 µg/g. And the concentration of Se and Cd in corn is 0.22 ± 0.96 µg/g and 0.15 ± 0.32 µg/g, respectively, which is mainly related to the high concentrations in soil. The benchmark dose limit of urinary Cd for ß2-microglobulin in subjects (n = 160) was calculated as 3.27 µg/g Cr. In view of crop-human dose effect and combining the relationship among the concentrations of crops and human biomarkers and the concentrations of crops and topsoil, this study established the models of land resource safety zoning. With that, the risk screening value of Cd in the soil could be obtained as 0.98 µg/g in this typical area. The proportions of priority utilization, safe utilization, and strict management of agricultural land area were 58.85%, 22.90%, and 18.25%, respectively, in Enshi, China. These results could provide scientific support for local agricultural development and ecological sustainability.

The Role of Selenium in Arsenic and Cadmium Toxicity: an Updated Review of Scientific Literature.

Arsenic (As) and cadmium (Cd) are elements arousing major public health concerns associated with environmental pollution, high toxicity potential, and carcinogenic nature. However, selenium (Se) at low doses and incorporated into enzymes and proteins has antioxidant properties and protects animals and humans from the risk of various diseases. It also has an exceptionally narrow range between necessary and toxic concentrations, which is a well-known hindrance in its use as a dietary supplement. The present article aims to update and expand the role of Se in As and Cd toxicity discussed in our earlier paper. In general, recent reports show that Se, regardless of its form (as selenite, selenomethionine, nanoSe, or Se from lentils), can reduce As- or Cd-mediated toxicity in the liver, kidney, spleen, brain, or heart in animal models and in cell culture studies. As was suggested in our earlier review, Se antagonizes the toxicity of As and Cd mainly through sequestration of these elements into biologically inert complexes and/or through the action of Se-dependent antioxidant enzymes. An increase in the As methylation efficiency is proposed as a possible mechanism by which Se can reduce As toxicity. However, new studies indicate that Se may also diminish As or Cd toxicity by activation of the Nrf2 pathway. In addition, this paper discusses possible signs of Se toxic effects, which may be a challenge for its future use in the therapy of As and Cd poisoning and provide future directions to address this issue.