Higher Se Concentrations Research Articles

Accumulation of trace elements in leatherback turtle (Dermochelys coriacea) eggs from the south-western Caribbean indicates potential health risks to consumers.

Trace metal and metalloid levels were measured in eggs of the NW Atlantic leatherback turtle (Dermochelys coriacea) from nesting grounds in the Bocas del Toro province, Panama, to infer exposure and associated risks to local communities. Samples were analyzed for a set of 26 essential and non-essential elements using inductively coupled plasma techniques. Median concentrations of Fe, Zn, As, Se and Sr in D.coriacea eggs were higher than previously reported for this species, which likely reflects differential contamination levels of specimens during foraging. The evaluation of non-carcinogenic human health risks from ingesting leatherback eggs has revealed potential deleterious effects due to high concentrations of As, Se and Sr for all examined age and gender groups, while Hg and Zn levels were above international standards for children. Hazard index (HI) values exceeded unity in all cases indicating serious health impacts related to possible additive effects of multiple metals co-occurring in the eggs. Our findings suggest that exposure to high (inorganic) As and Cr(VI) levels is associated with an increased carcinogenic risk, significantly exceeding the acceptable lifetime risk of 10-6 for both adults and children. Despite some limitations, such as unclear As and Cr speciation, our results demonstrated that the ingestion of D.coriacea eggs poses considerable health risks to local communities, and their consumption should not exceed 3.4×10-4g (5.0×10-6 eggs) kg BW d-1. Resource managers and conservationists should focus their attention to human health effects as an alternative tool to address egg poaching and consumption.

Absorption and Transportation of Selenium Nanoparticles in Wheat and Rice

Hydroponics experiments were carried out to study the effects of different sizes of selenium nanoparticles (SeNPs) and different pH on the absorption and transportation of Se by wheat (Triticum aestivum L.) and rice (Oryza sativa L.). The results showed that SeNPs with different sizes (50, 100, and 150 nm) had various characteristics with respect to absorption and translocation in wheat and rice. There was no significant difference in the uptake of SeNPs with different sizes by wheat roots after 24 h and 72 h; however, the highest Se content in wheat shoots was (1.89±0.47) μg·g-1 dry weight (DW) and (5.18±1.51) μg·g-1 DW under the 50 nm SeNPs treatment after 24 h and 72 h, respectively. Moreover, the transfer factor for Se in wheat under the 50 nm SeNPs treatment was 2.38 times higher than that of the 100 nm and 150 nm treatments. The Se content of rice roots treated for 24 h with the 50 nm SeNPs increased by 11.18% and 41.81% compared to those treated with the 100 nm and 150 nm SeNPs, respectively. There were, however, no significant differences in Se content between all of the SeNPs treatments after 72 h. The Se content of rice shoots and the Se transfer factor both reached the maximum when 50 nm SeNPs were applied. In addition, Se absorption by plants was also affected by pH. Specifically, the amount of Se absorbed by wheat roots treated with SeNPs was the greatest at a pH of 6 after 24 h, which was 89.47% higher than wheat treated with selenite. Furthermore, the highest Se transfer factor occurred at a pH of 4 in wheat. The uptake of SeNPs in rice was markedly lower than that of selenite at low pH values (pH=3.5 and 5.5) and SeNPs was more readily transported at a pH of 3.5. These results demonstrate that SeNPs could be taken up by wheat and rice and that it could be transferred more easily as small particle size (50 nm) than the larger ones (100 nm and 150 nm) at low pH values (pH 3.5).

Agronomic biofortification of rice (Oryza sativa L.) with selenium and its effect on element distributions in biofortified grains

Taking into account the relevance of biofortification of crop plants with selenium (Se) - an essential element for humans and animals -, this study assessed the effect of adding Se in the soil (as selenate) on: i) rice grains yield; ii) Se contents in polished rice grains; iii) physiological traits in rice leaves; and, iv) spatial distribution of Se and other elements in biofortified grains. A field trial was conducted using five Se rates (12, 21, 38, 68, and 120 g ha−1). Physiologic and enzymatic evaluations were carried out in rice leaves. Rice grain yield and Se contents were assessed. Spatial distributions of Se and other elements were visualized mapping the biofortified rice grains with μXRF at Brazilian Synchrotron Light Source. Results showed that soil Se application was effective in producing rice grains with higher Se contents, yet no effects were verified on rice yield. Antioxidant enzyme activities and gas exchanges in rice leaves changed following the application of Se. The spatial distribution of different elements in biofortified grains varied, with Se being accumulated mainly in the rice endosperm. Our results suggest that soil application of 47 and 36 g ha−1 of Se (as sodium selenate) may guarantee the production of rice grains with adequate Se levels for human consumption in Brazil and worldwide, respectively.

An evaluation of dietary selenium nanoparticles for red sea bream (Pagrus major) aquaculture: growth, tissue bioaccumulation, and antioxidative responses.

Selenium nanoparticles (Se-NPs) were added at 0, 0.5, 1, and 2 mg per kg diet to assess its effects on the performance, Se bioaccumulation, blood health, and antioxidant status of red sea bream. After 45 days, Se-NPs positively impacted the growth and feed efficiency of red sea bream especially by 1 mg per kg diet. No significant (P > 0.05) changes in survival and somatic indices were noticed among groups. Dietary Se-NPs significantly (P < 0.05) increased the protein, lipid, and Se contents in the whole body, muscle, and liver tissues, whereas decreasing the whole-body moisture content of treated groups compared with the Se-NP-free group. Using of Se-NPs at 2 mg per kg diet resulted in the highest Se content in the complete body, muscle, and liver. Significantly enhanced intestine protease activity and hematocrit levels accompanied with low cholesterol and triglyceride were observed in fish fed Se-NP-enriched diets. Fish fed on Se-NPs at 0.5, 1, and 2 mg Se-NPs per kg diet exhibited significantly higher values of biological antioxidant potential than the control group (P < 0.05). Therefore, the obtained results recommends adding 1 mg Se-NPs per kg diet to improve the growth, feed efficiency, blood health, and antioxidant defense system of red sea bream.

Assessing the uptake of selenium from naturally enriched soils by maize (Zea mays L.) using diffusive gradients in thin-films technique (DGT) and traditional extractions

A generally accepted method to predict selenium (Se) bioavailability of long-term contaminated soils has not yet been established, even if risk assessments in selenosis areas are crucial. In this study, a set of methods were tested to assess the bioavailability of Se to field maize. Fifty maize (Zea mays L.) samples and corresponding soils were collected from a selenosis area (Ziyang, China). The diffusive gradients in thin-films (DGT) technique and the traditional chemical extraction methods, including seven single-step extraction procedures and a five-step sequential extraction were used to predict the bioaccumulation of Se in plant. The result verified the presence of 50% of total Se in the form of residual Se fraction, followed by organic-bound and Fe-Mn oxide-bound Se fractions in soil. In addition, Se6+, Se4+, and Se2− were all detected in the solution extracted by H2O, KCl, phosphate-buffered solution (PBS), NaHCO3, ethylenediaminetetraacetic acid-2Na (EDTA-2Na) and ammonium bicarbonate–diethylenetriaminepentaacetic acid (AB-DTPA), but Se6+ was not extracted by NaOH. The Se extracted by single-step extraction methods was weakly correlated with the Se uptake by plants with relatively high Se concentration (>3 mg·kg−1). The abilities of the tested methods to predict Se bioavailability in naturally Se-enriched soils declined in the following order: DGT > soil solution > PBS > KCl > H2O > NaHCO3 > EDTA > DTPA > NaOH. The ratio of CDGT to soil solution Se (Csoln) totaled 0.13, indicating an extremely low Se supply from the soil solid phase to the soil solution. Se measured by DGT was mainly derived from the soluble and exchangeable Se fractions that can accurately reflect the plant-absorbed Se pool. Therefore, the DGT technique is highly applicable in the simultaneous prediction of Se bioavailability in naturally Se-enriched soils.

Catechins-Modified Selenium-Doped Hydroxyapatite Nanomaterials for Improved Osteosarcoma Therapy Through Generation of Reactive Oxygen Species.

Osteosarcoma is the most common bone cancer with limited therapeutic options. It can be treated by selenium-doped hydroxyapatite owing to its known antitumor potential. However, a high concentration of Se is toxic toward normal and stem cells whereas its low concentration cannot effectively remove cancer cells. Therefore, the current study was aimed to improve the anticancer activity of Se-HAp nanoparticles through catechins (CC) modification owing to their high cancer therapeutic value. The sequentially developed catechins modified Se-HAp nanocomposites (CC/Se-HAp) were characterized for various physico-chemical properties and antitumor activity. Structural analysis showed the synthesis of small rod-like single phase HAp nanoparticles (60 ± 15 nm), which effectively interacted with Se and catechins and formed agglomerated structures. TEM analysis showed the internalization and degradation of CC/Se-HAp nanomaterials within MNNG/HOS cells through a non-specific endocytosis process. Cell toxicity analysis showed that catechins modification improved the antitumor activity of Se-HAp nanocomposites by inducing apoptosis of human osteosarcoma MNNG/HOS cell lines, through generation of reactive oxygen species (ROS) which in turn activated the caspase-3 pathway, without significantly affecting the growth of human normal bone marrow stem cells (hBMSCs). qPCR and western blot analyses revealed that casp3, p53, and bax genes were significantly upregulated while cox-2 and PTK-2 were slightly downregulated as compared to control in CC/Se-HAp-treated MNNG/HOS cell lines. The current study of combining natural biomaterial (i.e., catechins) with Se and HAp, can prove to be an effective therapeutic approach for bone cancer therapy.

The mineralization process of the Lanuoma Pb-Zn-Sb deposit in the Sanjiang Tethys region: Constraints from in situ sulfur isotopes and trace element compositions

The Lanuoma deposit, located in the Sanjiang Tethyan metallogenic domain, shows a characteristic assemblage of Pb-Zn-Sb mineralization, distinguished from those in other sediment-hosted base metal deposits of this region. The ore textures reveal two mineralization stages: the early stage is characterized by Zn mineralization with occurrences of porous pyrite (Py2) and yellowish-brown sphalerites (Sp1), and the late stage is characterized by Sb-Pb mineralization with occurrences of subhedral-euhedral pyrite (Py3), yellowish-white sphalerites (Sp2), sulfosalts consisting of boulangerite, zinkenite, sorbyite and plagionite and calcite veins. The framboidal pyrites (Py1) predate Pb-Zn-Sb mineralization. Py2 has higher Zn contents (16.97–621.67 ppm, mean: 181.17 ppm) than Py3 (Zn: 0.76–323.44 ppm, mean: 29.58 ppm) by up to one order of magnitude. The Se contents of Py2 (Se: 5.46–87.82 ppm, mean: 50.96 ppm) are also one order of magnitude higher than those of Py3 (Se: 1.64–10.99 ppm, mean: 4.35 ppm). Sp1 is characterized by one order of magnitude higher contents of Fe (381.99–9046.64, mean: 4875.50 ppm) and Se (4.02–72.51 ppm, mean: 34.70 ppm) than Sp2 (Fe: 287.53–584.02 ppm, mean: 416.75 ppm; Se: 2.89–10.80 ppm, mean: 6.20 ppm). However, the average content of Cd (4256.38 ppm) in Sp2 is almost twice that in Sp1 (2635.74 ppm). The higher Se contents in Py2 coupled with higher Se and Fe contents in Sp1 indicate that Py2 and Sp1 had higher precipitation temperatures than Py3 and Sp2. Sulfur isotope compositions of pyrites and sphalerites acquired by NANO-SIMS and LA-MC-ICP-MS suggest two origins: the sulfur of Py2 (δ34S: −3.0 to 2.3‰), Sp1 (δ34S: 0.2–0.9‰) and Sp2 (δ34S: 0.7–2.5‰) was mainly of magmatic source, and sulfur reduced via thermochemical sulfate reduction participated in the formation of Py3 (δ34S: 0.2–6.0‰) and S-Sb-Pb minerals intergrown with Py3. The sulfur isotope compositions of Py1 (δ34S: −31.8 to −19.4‰) indicate a biogenic origin associated with bacterial sulfate reduction. A fluid mixing model is suggested to interpret the genesis of the Lanuoma Pb-Zn-Sb deposit: mixing of a reduced S-bearing fluid with a metalliferous basinal brine resulted in the precipitation of sulfides. Temperature was the most important factor controlling metal precipitation in the Lanuoma deposit.

Circulating Selenium Concentration Is Inversely Associated With the Prevalence of Stroke: Results From the Canadian Health Measures Survey and the National Health and Nutrition Examination Survey.

BackgroundObservational studies have suggested that selenium (Se) may have beneficial effects against certain cardiovascular outcomes, with a possible U‐shaped association. We assessed the hypothesis that blood Se concentration might be inversely associated with the prevalence of stroke and the relationship would be nonlinear.Methods and ResultsData collected from adult participants (aged ≥20 years) in the Canadian Health Measures Survey (CHMS 2007–2011, n=7065) and the US National Health and Nutrition Examination Survey (NHANES 2011–2012, n=5030) were analyzed. A total of 82 (1.16%) and 202 (4.02%) stroke cases were identified in CHMS and NHANES. Respondents with stroke had lower Se levels than those without stroke, with a mean difference of 16 μg/L and 12 μg/L for CHMS and NHANES, respectively. Respondents with high blood Se concentration (tertile 3) had a lower prevalence of stroke compared with those with low Se concentration (tertile 1). The adjusted odds ratios were 0.38 (95% CI: 0.15, 0.92) and 0.57 (95% CI: 0.31, 1.03) for CHMS and NHANES, respectively. A continuous decreasing trend of stroke with whole blood selenium was observed in CHMS, whereas the curve plateaued starting at 190 μg/L for NHANES, based on the cubic restricted spline regression. Sensitivity analysis using the serum and urinary Se concentrations demonstrates that our results were consistent across different selenium biomarkers.ConclusionsWe observed inverse cross‐sectional associations between whole blood Se and the prevalence of stroke in representative samples of the Canadian and the US population.

The Lower Banded series of the Stillwater Complex, Montana: whole-rock lithophile, chalcophile, and platinum-group element distributions

The principal rock types of the Lower Banded series of the Stillwater Complex are gabbronorite and norite with minor troctolite and anorthosite. The whole-rock composition is largely controlled by the cumulate minerals plagioclase and pyroxene (±olivine). The rocks are very poor in incompatible elements, at the 0.1 to 2 times mantle levels, indicating < 10% liquid fraction. The Pd and Pt are enriched in a layer known as the J-M Reef which occurs in a zone containing olivine-bearing rocks (OB I). This zone contains the same rock types as the rest of the Lower Banded series, but troctolite, olivine gabbronorite, and anorthosite are more abundant in OB I. The concentrations of lithophile elements in OB I are similar to the rocks above and below OB I. In particular, the reef rocks show no additional signs of continental crust contamination such as additional Th or LREE enrichment, and the reef rocks are not enriched in incompatible elements. The strongly chalcophile elements Cu, Ni, Se, Bi, and Au all correlate with S, indicating that these elements are controlled by sulfides. The PGE show two trends. The rocks below the J-M Reef and the reef rocks have high PGE+Au to S ratios and fall on a single trend, whereas those above the reef have low metal to S ratios. These low ratios for the rocks above the reef could arise because the magma was depleted in PGE+Au as it had already segregated some PGE+Au-rich sulfides. The relatively high PGE, Au, Cu, and Se concentrations of the rocks below the reef imply that the rocks contain ~ 0.1 wt% cumulate sulfides. However, they have very low S contents (< 300 ppm). The low S/Se ratios of these rocks (< 2000) and most of the rocks outside of the reef suggest that they have lost more than half of their S. The Pd/Pt and Pd/Ir ratios of the reef (~ 3.4 and 800, respectively) are much higher than those of the rocks below and above the reef. The high Pd/Pt and Pd/Ir ratios of the reef imply that the sulfides formed from a fractionated magma; however, there is no correlation between the Pd/Ir and Pd/Pt ratios and the host rock type. These ratios are dissimilar to the Bushveld reefs and the Main Sulfide Zone of the Great Dyke. They more closely resemble the reefs in more fractionated rocks such as the AP Reef of the Penikat Intrusion, the Roby Zone of the Lac des Iles Complex, or the disseminated sulfides of the Noril’sk I intrusion. The very high Pd/S and low Cu/Pd ratios of the J-M Reef require that the sulfides collected Pd from a very large volume of magma. None of the current models is entirely satisfactory; however, we favor a model where at depth the OB1 magma partially melted a komatiitic massive sulfide and then transported the sulfide droplets into the magma chamber at the level of the J-M reef.

Selenium lowers bulk recombination

Selenium alloying has enabled record efficiency for CdTe solar cells by changing the optoelectronic properties of the CdTe absorber layer, though its role has not yet been fully understood. Now, non-radiative charge-carrier recombination in the bulk of the CdSeTe layer is revealed to be lower in grains with higher Se concentration.

Survival of selenium-enriched lactic acid bacteria in a fermented drink under storage and simulated gastro-intestinal digestion.

Selenium (Se), which is present as SeCys in seleno-proteins, is involved in cancer prevention, thyroid functioning, and pathogen inhibition. Se is incorporated in the diet through Se-containing foods. Some lactic acid bacteria (LAB) can biotransform selenite (toxic) into Se-nanoparticles (SeNPs) and Se-amino acids. To exert their beneficial properties in the host, bacteria should survive the harsh conditions of the gastrointestinal tract and during food storage. We evaluated whether selenization of LAB influenced bacterial growth and survival during gastrointestinal digestion and after storage when present in a fermented fruit juice-milk (FJM) beverage. Lactobacillus brevis CRL 2051 and Fructobacillus tropaeoli CRL 2034 were grown in MRS with and without selenite, and used to inoculate the FJM matrix. Selenization had no effect on LAB growth (9.54-9.9 log CFU/mL) in the FJM drink. The presence of SeNPs was confirmed for both selenized strains in the FJM beverage; however, the highest Se concentration (100 μg/L) was detected for the fermented beverage with selenized L. brevis. Under storage conditions 1.1 log CFU/ml decrease in cell count of selenized cells of L. brevis was observed, while no effect on cell viability was detected for non-selenized L. brevis or both selenized and control cells of F. tropaeoli. Resistance of L. brevis during digestion of the fermented FJM beverage was not affected by selenization. Contrarily, an increase (1 log CFU/mL) in the resistance of F. tropaeoli was observed when cells were selenized. After digestion, Se was detected in the soluble fraction of the beverage fermented by both strains, being higher for L. brevis (23.6 μg/L). Although selenization did not exert a drastic effect on strains´ survival during storage and digestion, microbial selenization previous to food fermentation could be an interesting tool for Se enrichment avoiding thus the addition of toxic Se salts.

Selenium in pyrite ores

Own Se minerals, first established in primary ores of VMS deposits of the Urals, are described. Instrumental neutron activation analysis of bulk ore samples, mineral monofractions and local methods of analysis: LA-ICP- MS, electron probe microanalysis and analytical electron microscopy were used. CSe in ores of the Urals to 977 g/t. Significant positive correlation of Se with Te, S, Fe, Co, Mo, Hg, Bi is characteristic. Selenium is con- centrated in the main sulfides, mainly in pyrite (73 g/t), chalcopyrite 49 g/t, pyrrhotite 48 g/t; in sphalerite usually &lt;10 g/t. High Se content (up to 1–3 wt.%) occurs in the minor and rare minerals from massive sulfide ores (mainly compounds of Pb, Te, Bi): tetradymite, galena, tellurobismuthite, altaite, wittichenite. Own Se minerals in ores are represented by kawazulite, clausthalite, galena-clausthalite Pb(Se,S), micron inclusions composition (Ag, Cu)2(Se, S), (Ag, Pb)3(Te, Se)S, (Ag, Pb)2(S, Se).

Effect of dietary selenium in rainbow trout (Oncorhynchus mykiss) broodstock on antioxidant status, its parental transfer and oxidative status in the progeny

We studied the effects of supplementing a plant-ingredient based rainbow trout broodstock diet with different forms of selenium (Se) on reproductive performance, parental Se transfer and antioxidant metabolism in their progeny before first-feeding. Three groups of rainbow trout were fed a diet either without selenium supplementation (NC, basal Se level: 0.3 ppm) or supplemented with 0.3 ppm Se either in the form of sodium selenite (SS) or as hydroxy-selenomethionine (SO, dietary Se level: 0.7 ppm) over a 6-month period prior to spawning. In Se-supplemented groups, the total number of females spawning was significantly higher compared to the negative control group and the females fed SO began to spawn earlier compared to females fed SS or NC. Total Se concentrations were significantly higher in female muscle of SO group. Higher Se concentrations in the oocytes of both Se-supplemented groups confirmed a maternal transfer of Se, while total Se concentrations in milt samples were not significantly different between dietary groups. There was no effect on glutathione peroxidase (GPX) or other antioxidant enzyme activity in the liver of female or male broodstock, whereas in the swim-up fry, GPX activity was significantly higher in both Se-supplemented treatments with the highest activity in the SO group. Se-supplementation enhanced the expression of hepatic SelPa in broodstock males and females along with MsrB1, GPx1a, GPx4a2, CAT, Gclc, Keap1 and MsrB2 in male liver. In swim-up fry, only organic Se-supplementation led to a higher gene expression for SelPa, GPX1a, GPX1b2, CAT and MsrB2. An improvement of the oxidative status in whole-body of swim-up fry could not be confirmed in this study as the GSH/GSSG was even lower in swim-up fry of Se-supplemented groups, whereas the 8-isoprostane levels were lower in the SS group and no effect on protein carbonyl levels could be detected. Organic Se-supplementation led to a significant increase in the α-tocopherol and vitamin C levels in the progeny. These results show that dietary Se in broodstock nutrition influences spawning occurrence and along with the parental transfer, several traits in the progeny are affected.

Selenium and mercury concentration in drinking water and food samples from a coal mining area in Brazil.

Selenium (Se) is an essential element for human health and can also alleviate the toxicity of elements such as mercury (Hg), which is considered deleterious to health. The study area is an important coal mineral region in Brazil, generating 40% of all Brazilian coal. During the coal mining process, Se and Hg are released, which can induce potential human health risks via the food chain. The purpose of the present study is to determine total Se and its species and total Hg in drinking water and food locally produced from a coal mining area, to assess the impact of coal mining. The samples were collected in two cities, with and without coal mining influence. Total Se levels in drinking water and food were assessed by inductively coupled plasma mass spectrometry (ICP-MS) and its species by high-performance liquid-ICP-MS, while total Hg was determined by cold vapor atomic fluorescence spectrometry. Drinking water (1.1 ± 0.2 mg L-1 dry weight) (p = 0.02) and tomatoes (1.5 ± 0.1 mg kg-1 dry weight) (p = 0.01) from the coal mining area had higher total Se concentration than the control area. The highest Se concentrations were found in animal-based food (6.4 ± 0.8 mg kg-1 dry weight) with an important contribution of Se IV (65%). The analyzed sample did not accumulate a significant amount of Hg. Future studies on the estimates of daily intake of these elements and dietary pattern of the population are needed to make appropriate dietary recommendations and support public health action.

Contamination assessment and prediction of 27 trace elements in sediment core from an urban lake associated with land use.

A sediment core was sampled in an urban lake in southern Brazil, and the presence of 27 trace elements was assessed. The geochronology showed that the core corresponds to the period from 1914 to 2012. Accumulation of metals and the level of pollution was measured by the geoaccumulation index (Igeo) and enrichment factor (EF). According to Igeo and EF, the lake showed a high concentration of Ag, Se, Na, Au, S, Ca, Mg, Ba, Sb, Bi, and Sr with 5 ≤ EF ≤ 45 and Igeo class = 2-6. The EF to Au = 45 and Ag = 40. In contrast, Fe, Al, As, Cr, Ga, La, Sc, and Th do not represent pollution (Igeo ≤ 0 and EF ≤ 1.6). A principal component analysis and Spearman correlation showed a first group composed of Ca, Mg, P, Ba, Sr, Na, K, Ag, Bi, Au, Mo, sand, silt, and total organic carbon with positive correlation ≥ 0.70 and > 0.95 to Sr, Ag, sand, and silt. These were negatively correlated ≥- 0.70 with Fe. The second group: Fe, La, Ga, Ti, V, Cr, As, Al, Th from lithogenic source. Prediction models for the concentration for Mg, Na, P, Sr, Fe, Ga, and total organic carbon to years 2020-2050 were obtained with R2 > 0.65. In the anthropogenic source analyses, a watershed land use map indicates multiple uses of the land, with 53% urban area, 14.6% agriculture, and 14.5% forest.

Determination of selenium content in selected edible green leaves

The selenium (Se) contents in seven conventional Edible Green Leaves (EGL) that consumed by Sri Lankans were determined using Hydride Generation Atomic Absorption Spectrometric method (HGAAS). The EGLs that were grown in five districts under different climatic conditions in Sri Lanka were collected from Gampaha, Kandy, Kurunegala, Anuradhapura and Puttalam areas. The EGL that were subjected to current study are Centella asiatica ( Sin . Gotukola ), Alternanthra sessilis ( Sin . Mukunuwenna ), Basella alba ( Sin . Nivithi / Spinach ), Boerhavia diffusa ( Sin . Sarana ), Ipomoea aquatica ( Sin . Kankun ), Amaranthus spinosus ( Sin . Thampala ) and Hygrophila schulli ( Sin . Neeramulliya ). Soil samples corresponding to each EGL sample were also collected from Gampaha, Kandy and Anuradhapura districts in order identify a relationship between the Se content in plants and soils. Prior to the analysis EGL samples and corresponding soil samples were subjected to acid digestion with nitric acid. Se contents in the EGL were in the range of 31.2 – 103.2 μg kg -1 on dry weight basis. According to the results, Centella asiatica and Hygrophila schulli varieties showed relatively higher Se content, while Hygrophila schulli shown the highest value and the lowest was reported in Boerhavia diffusa . The Se content in corresponding soil samples were ranged from 96.4 to 133.9 μg kg -1 on dry weight basis. The Se content in soil was higher than that in plants, but there was no significant correlation between the Se content in soil and EGLs.

Selenium translocation in the soil-rice system in the Enshi seleniferous area, Central China

Rice is an important source of selenium (Se) exposure; however, the transformation and translocation of Se in the soil-rice system remain poorly understood. Here, we investigated the speciation of Se in Se-rich soils from Enshi, Central China and assessed which Se species is bioavailable for rice grown in Enshi. Extremely high Se concentrations (0.85 to 11.46 mg/kg) were observed in the soils. The soil Se fractions, which include water-soluble Se (0.2 to 3.4%), ligand-exchangeable Se (4.5 to 15.0%), organically bound Se (57.8 to 80.0%) and residual Se (6.1 to 32.9%), are largely controlled by soil organic matter (SOM) levels. Decomposition of SOM promotes the transformation of organically bound Se to water-soluble Se and ligand-exchangeable Se, thereby increasing the bioavailability of Se. The bioaccumulation factors (BAFs) of Se decrease in the following order: roots (0.84 ± 0.30) > bran (0.33 ± 0.17) > leaves (0.18 ± 0.09) > polished rice (0.14 ± 0.07) > stems (0.12 ± 0.07) > husks (0.11 ± 0.07). Selenium levels in rice plants are affected by multiple soil Se fractions in the soil. Water-soluble, ligand-exchangeable and organically bound Se fractions are the major sources of Se in rice tissues.

Consumption of Brazil nuts with high selenium levels increased inflammation biomarkers in obese women: A randomized controlled trial.

Increased inflammatory response is an important factor in the pathophysiology of obesity. The mineral selenium (Se), of which one of the main food sources is the Brazil nut, has important antioxidant and anti-inflammatory functions through the action of selenoproteins. Thus, the evaluation of the influence of this micronutrient in this context is of great relevance. The aim of this study was to evaluate the effects of Brazil nut intake with high Se concentrations on inflammatory biomarkers and its relation to Se status in obese women. A randomized controlled clinical trial was carried out with 55 women recruited at Clinical Hospital in São Paulo, Brazil. Patients were randomly assigned to either the Brazil nut group (BN) or the control group (CO) and followed up for 2 mo. The BN group consumed 1 unit/d of Brazil nuts (∼ 1261 μg/Se); the CO group did not receive any intervention. At baseline and after 2 mo, analysis of biochemical parameters related to Se status, oxidative stress, and inflammatory biomarkers were performed. At baseline, both groups did not present Se deficiency. In the BN group, a significant increase (P < 0.05) in all Se biomarkers and in gene expression of several proinflammatory parameters (interleukin-6, tumor necrosis factor-α, and Toll-like receptors 2 and 4) were observed after the intervention period. No changes were observed for the CO group. Although there were no changes in plasma inflammatory biomarkers levels, a significant increase in gene expression may be an indication of a proinflammatory stimulus in obesity, induced by the consumption of Brazil nuts with high Se levels.

Effect of dietary Bio-fermented selenium on growth performance, nonspecific immune enzyme, proximate composition and bioaccumulation of zebrafish (Danio rerio)

A four-weeks feeding trial was conducted to evaluate the effects of dietary Bio-fermented selenium (Bio-Se) on zebrafish (Danio rerio). Effects of three Se diets containing basal diet (1.63 mg Se/kg), L-Se diet (3 mg Se/kg), and H-Se diet (10 mg Se/kg) on growth performance, nonspecific immune enzyme activities, proximate composition, and selenium accumulation of zebrafish were tested. The results indicate that body weight gain (BWG), specific growth rate (SGR), and nonspecific immune enzyme [glutathione peroxidase (GPx), superoxide dismutase (SOD), and alkaline phosphatase (ALP)] activities of fish fed with L-Se diet were significantly highest among all the groups. However, increased H2O2 content and decreased SOD activity indicates oxidative stress when fish was fed with H-Se diet. Dietary Se did not affect the proximate composition of zebrafish. The Se concentration in muscle increased in a dose-dependent manner, and the highest Se concentration was recorded in H-Se diet. In summary, the growth performance and nonspecific immunity of zebrafish fed with L-Se diet improved, but exposure to higher concentrations of Bio-Se severely affects the health status of fish.

Element Concentrations in Tree Swallows (Tachycineta bicolor) from the U.S. and Binational Great Lakes Areas of Concern.

Selected elements were targeted in state Remedial Action Plans as one group of chemicals affecting the Beneficial Use Impairments of Great Lakes Areas of Concern (AOCs). Livers of nestling tree swallows, Tachycineta bicolor, were harvested from 76 sites in the Great Lakes, which included multiple sites at 27 AOCs and 12 reference sites from 2010 to 2015, and were analyzed for 21 elements. Mercury concentrations were at background levels at all sites. Elevated cadmium (Cd) concentrations were associated with industry. The highest Cd values were from the Black River, OH AOC and were associated with historic coke production but were not at toxic levels. Lead (Pb) concentrations were highest on the Rouge River, MI AOC-the oldest and most heavily populated and industrialized area in southeast Michigan. Individual Pb concentrations were elevated to a level associated with delta-aminolaevulinic acid dehydratase inhibition but not to a level considered toxic. In contrast, livers harvested from sites on the southwest shore of Lake Michigan had selenium (Se) concentrations elevated to levels associated with reduced avian reproduction. One likely source of the high Se concentrations was pollution from a local coal-fired power plant. Concentrations of the remaining elements were at background levels.