Precise Determination of Selenium Forms and Contents in Selenium-Enriched Rapeseed Seedlings and Flowering Stalks by HPLC-ICP-MS.

Rapeseed (Brassica napus L.) has the ability of selenium (Se) enrichment. Identification of selenides in Se-rich rapeseed products will promote the development and utilization of high value. By optimizing the Se species extraction process (protease type, extraction reagent, enzyme sample ratio, extraction time, etc.) and chromatographic column, an efficient, stable, and accurate method was established for the identification of Se species and content in rapeseed seedlings and flowering stalks, which were cultured by inorganic Se hydroponics. Five Se compounds, including selenocystine (SeCys2), methylselenocysteine (MeSeCys), selenomethionine (SeMet), selenite (SeIV), and selenate (SeVI) were qualitatively and quantitatively identified. Organoselenium was absolutely dominant in both seedlings and flowering stalks among the detected rapeseed varieties, with 64.18-90.20% and 94.38-98.47%, respectively. Further, MeSeCys, a highly active selenide, predominated in rapeseed flowering stalks with a proportion of 56.36-72.93% and a content of 1707.3-5030.3 µg/kg. This study provides a new source of MeSeCys supplementation for human Se fortification.

Monitoring of Essential and Toxic Elements in Multivitamin/Mineral Effervescent Tablet Supplements and Safety Assessment.

Multivitamin/mineral (MVM) supplements are the most commonly utilized dietary supplements by many populations. However, there is a severe concern about their adverse effects due to elemental impurities. In the present study, it was aimed to determine the levels of 11 elemental impurities (Cd, Pb, As, Hg, Co, V, Ni, Se, Mo, Cu, and Cr) by inductively coupled plasma-mass spectrometry (ICP-MS) and evaluate the human health risk associated with the consumption of 33 MVM effervescent tablet supplements available in Turkey. The precision of the method in terms of relative standard deviation (RSD) was less than 4.6%. The accuracy of the method was tested with recovery experiments, and the results ranged between 86 and 107%. The impurity levels for Cd, Pb, As, Co, V, Ni, Se, Mo, Cu, and Cr were found between 0.011-0.050, 0.025-0.098, 0.018-0.056, 0.010-0.626, 0.027-0.290, 0.026-1.65, 1.92-21.83, 0.034-34.09, 0.140-183.9, and 0.033-13.10 µg/g, respectively, and Hg was not detected in any sample. The calculated concentrations for elemental impurities complied with EMA and USP guidelines, except one supplement for Se (21.83 µg/g) with a permitted limit of 15 µg/g. The hazard quotient (HQ) and hazard index (HI) levels were below 1 for all samples within the ranges of 3.4 × 10-1-1.4 × 10-6 for HQ and 7.8 × 10-1-1.4 × 10-6 for HI indicating that there is no risk for consumption. The carcinogenic risk (CR) of As was between 1.7 × 10-6 and 5.9 × 10-6, below the threshold value of 1 × 10-4. The results showed that there is no risk to human health.

Direct elemental analysis of plant oils by inductively coupled plasma mass spectrometry: Simple sample dilution combined with oxygen introduction into the plasma.

Assessment of trace metal concentrations in plant oils has been considered a crucial quality control marker for potential health risks, oil flavour, and oxidative stability. A straightforward inductively coupled plasma mass spectrometry (ICP-MS) methodology was developed and validated through introduction of argon:oxygen gas mixture into plasma, allowing for a direct elemental analysis of organic matrices. This approach offers the advantage of a simple one-step preparation of plant oil samples with negligible contamination risks. The complete solubilization of the oil matrix enables the determination of total metal content from a single test tube with low dilution factor of 5. The modified plasma conditions resulted in the development of a robust and accurate ICP-MS method providing limits of detection at sub ng·g-1 levels. The ICP-MS method allowed the determination of trace levels of Ba, Cd, Cu, Fe, Mn, Pb, Sn, V, and Zn in olive, sunflower and rapeseed oils.

Determination of the median lethal dose of zinc gluconate in mice and safety evaluation.

BACKGROUND: Zinc Gluconate (ZG) is a safe and effective supplement for zinc. However, there is limited research on the optimal dosage for intravenous injection and the safety evaluation of animal models for ZG. This study aims to determine the safe dose range of ZG for intravenous injection in C57BL/6J mice. METHODS: A Dose titration experiment was conducted to determine the LD50 and 95% confidence interval (95%CI) of ZG in mice. Based on the LD50, four sub-lethal doses (SLD) of ZG were evaluated. Following three injections of each SLD and monitoring for seven days, serum zinc levels were measured, and pathological changes in the liver, kidney, and spleen tissues of mice were determined by histological staining. RESULTS: The dose titration experiment determined the LD50 of ZG in mice to be 39.6 mg/kg, with a 95%CI of 31.8-49.3 mg/kg. There was a statistically significant difference in the overall serum zinc levels (H = 36.912, P < 0.001) following SLD administration. Pairwise comparisons showed that the serum zinc levels of the 1/2 LD50 and 3/4 LD50 groups were significantly higher than those of the control group (P < 0.001); the serum zinc level of the 3/4 LD50 group was significantly higher than those of the 1/8 LD50 and 1/4 LD50 groups (P < 0.05). There was a positive correlation between the different SLDs of ZG and the serum zinc levels in mice (rs = 0.973, P < 0.001). H&E staining showed no significant histological abnormalities or lesions in the liver, kidney, and spleen tissues of mice in all experimental groups. CONCLUSION: The appropriate dose range of ZG for intravenous injection in C57BL/6J mice was clarified, providing a reference for future experimental research.

Certification of New Selenium-Enriched Yeast and Supplement Reference Materials for Selenomethionine Using Two Independent Measurement Strategies.

Selenium-enriched yeast possesses the unique ability of transforming chemical selenium, such as sodium selenite, into a biologically active form, which mitigates its toxic effects on the human body. The transformation product of this process, selenomethionine, can be safely and effectively absorbed and utilized by the human body; hence, it has been spiked into a selenium-enriched supplement. This study employs two distinct measurement strategies to determine the selenomethionine content in two candidate reference materials, a selenium-enriched yeast powder and supplement, using both organic and inorganic mass spectrometry. The concentrations of selenomethionine in the selenium-enriched yeast were determined using HPLC-ICP-MS and HPLC- ESI-MS/MS, with mass fractions measured at 718 mg SeMet kg-1 and 715 mg SeMet kg-1, respectively. Notably, both methods yielded consistent results for the selenium supplement, with a selenomethionine mass fraction of 59 mg SeMet kg-1. Ultimately, the certified values of these candidate reference materials were determined as 716 mg kg-1 and 59 mg SeMet kg-1 with expanded uncertainties of 36 mg SeMet kg-1 (k = 2) and 5 mg SeMet kg-1 (k = 2), respectively. The development of these candidate reference materials serves as a valuable reference for diverse methods aiming to determine the value of organic selenium speciation in complex food substrates.

A one-class classification approach for authentication of specialty coffees by inductively coupled plasma mass spectroscopy (ICP-MS).

Due to the lucrative nature of specialty coffees, there have been instances of adulteration where low-cost materials are mixed in to increase the overall volume, resulting in illegal profit. A widely used and recommended approach to detect possible adulteration is the application of one-class classifiers (OCC), which only require information about the target class to build the models. Thus, this work aimed to identify adulterations in specialty coffees with low-quality coffee using multielement analysis determined by ICP-MS and to evaluate the performance of one-class classifiers (dd-SIMCA, OCRF, and OCPLS). Therefore, authentic specialty coffee samples were adulterated with low-quality coffee in 25 % to 75 % (w/w) proportions. Samples were subjected to acid decomposition for analysis by ICP-MS. OCPLS method presented the best performance to detect adulterations with low-quality coffee in specialty coffees, showing higher specificity (SPE = 100 %) and reliability rate (RLR = 94.3 %).

Selenium speciation studies in cancer patients to evaluate the responses of biomarkers of selenium status to different selenium compounds.

This work presents the first systematic comparison of selenium (Se) speciation in plasma from cancer patients treated orally with three Se compounds (sodium selenite, SS; L-selenomethionine, SeMet; or Se-methylselenocysteine, MSC) at 400 µg/day for 28 days. The primary goal was to investigate how these chemical forms of Se affect the plasma Se distribution, aiming to identify the most effective Se compound for optimal selenoprotein expression. This was achieved using methodology based on HPLC-ICP-MS after sample preparation/fractionation approaches. Measurements of total Se in plasma samples collected before and after 4 weeks of treatment showed that median total Se levels increased significantly from 89.6 to 126.4 µg kg-1 Se (p < 0.001), particularly when SeMet was administered (190.4 µg kg-1 Se). Speciation studies showed that the most critical differences between treated and baseline samples were seen for selenoprotein P (SELENOP) and selenoalbumin after administration with MSC (p = 5.8 × 10-4) and SeMet (p = 6.8 × 10-5), respectively. Notably, selenosugar-1 was detected in all low-molecular-weight plasma fractions following treatment, particularly with MSC. Two different chromatographic approaches and spiking experiments demonstrated that about 45% of that increase in SELENOP levels (to ~ 8.8 mg L-1) with SeMet is likely due to the non-specific incorporation of SeMet into the SELENOP affinity fraction. To the authors' knowledge, this has not been reported to date. Therefore, SELENOP is probably part of both the regulated (55%) and non-regulated (45%) Se pools after SeMet administration, whereas SS and MSC mainly contribute to the regulated one.

The Control and Comprehensive Safety Assessment of Heavy Metal Impurities (As, Pb, and Cd) in Green Tea Camellia sinensis (L.) Samples (Infusions) Available in Poland.

Tea is the world's most common drink after water, and the world's annual sales exceed $43 billion, of which more than $11 billion is green tea (Camellia sinensis (L.)). Increasing evidence continues to show that green tea consumption and its ingredients have a variety of potential health benefits. The aim of the study was to control and assess the toxicological risk (TRA) of three heavy metals (As, Pb, and Cd) in infusions of green tea (n = 12) from Polish markets. We applied the method of inductive coupled plasma mass spectrometry (ICP-MS) to determine the selected heavy metal and designed a specific toxicological risk assessment with three crucial tiers. The first tier of our strategy was to determine the elements investigated (heavy metal impurities, µg/L). The second step was to estimate the weekly intake of green tea infusions (µg/week) based on weekly consumption. The third tier was to estimate the weekly intake per weight (µg/L/week/bw), based on the average weekly intake of green tea infusion per adult compared to the provisional weekly intake (PTWI) established by the FAO/WHO Joint Food Additives Expert Committee (JECFA). The levels of the investigated heavy metals occur at different levels in all of the investigated green tea infusions. The heavy metal profile indicated that As (0.0721-10.585 µg/L), Pb (0.386-1.695 µg/L), and Cd (0.126-0.346 µg/L) were present in all samples. Basic analysis of general content shows that As (average = 0.325 µg/L) was at a level similar to Cd (average = 0.214 µg/L). Surprisingly, the Pb content (average 0.891 µg/L) was approximately 2.75-4 times higher than that of As and Cd, respectively. The application of our proposed safety assessment methodology (three tiers) provides satisfactory results for regulatory purposes. The evaluation of the investigated heavy metals in all products analysed from green tea samples (infusions) showed that there were no health hazards to consumers due to weekly exposure. The results indicated that after drinking green tea infusions from Polish markets, the amount of investigated elements in weekly doses does not represent any health risks to consumers.

Investigation of Heavy Metal Analysis on Medicinal Plants Used for the Treatment of Skin Cancer by Traditional Practitioners in Pretoria.

The use of medicinal plants for the treatment of diseases, including cancer, is acknowledged and accepted in many African nations. Heavy metal contamination of plant materials poses a potential health risk, particularly for populations that are already vulnerable. This study determines the levels of heavy metals in medicinal plant samples used for treatment of skin cancer and evaluate the health risk caused by heavy metals to the adult population in Pretoria, South Africa using inductively coupled plasma mass spectrometry (ICP-MS). The concentrations of metals were as follows; As (<0.2 - 1.04±0.026), Cd (0.02 ±0.00026 - 0.167±0.006), Pb (0.38 ±0.01 - 2.27±0.05), Cr (5.31±0.21- 26.9 ±3.96) mg/kg, and Hg which were lesser than 0.02 mg/kg. The mean concentrations of all analyzed heavy metals are above permissible limit except for Hg which are lower than the permissible limit. The Hazard Quotient (THQ) was less than 1 for all the heavy metals, suggesting that there are no obvious non-carcinogenic health risks associated with the consumption of these medicinal plants for now even though the prolonged use may result in health risks. The ingestion route was identified as the primary contributor to the overall risk by the health index (HI) values in the present study, which were more than 1, indicating that the combined effects of the heavy metal contaminants present in a particular herbal preparation pose health risk in the long term. Our findings support the need for close monitoring of potential heavy metal concentrations in medicinal plants given to patients from herbal shops.

Spatial distribution of trace metals and associated transport proteins during bacterial infection.

Innate immune systems alter the concentrations of trace elements in host niches in response to invading pathogens during infection. This work reports the interplay between d-block metal ions and their associated biomolecules using hyphenated elemental techniques to spatially quantify both elemental distributions and the abundance of specific transport proteins. Here, lung tissues were collected for analyses from naïve and Streptococcus pneumoniae-infected mice fed on a zinc-restricted or zinc-supplemented diet. Spatiotemporal distributions of manganese (55Mn), iron (56Fe), copper (63Cu), and zinc (66Zn) were determined by quantitative laser ablation-inductively coupled plasma-mass spectrometry. The murine transport proteins ZIP8 and ZIP14, which are associated with zinc transport, were also imaged by incorporation of immunohistochemistry techniques into the analytical workflow. Collectively, this work demonstrates the potential of a single instrumental platform suitable for multiplex analyses of tissues and labelled antibodies to investigate complex elemental interactions at the host-pathogen interface. Further, these methods have the potential for broad application to investigations of biological pathways where concomitant measurement of elements and biomolecules is crucial to understand the basis of disease and aid in development of new therapeutic approaches.

Mapping Phosphorus Availability in Soil at a Large Scale and High Resolution Using Novel Diffusive Gradients in Thin Films Designed for X-ray Fluorescence Microscopy.

A novel binding layer (BL) as part of the diffusive gradients in thin films (DGT) technique was developed for the two-dimensional visualization and quantification of labile phosphorus (P) in soils. This BL was designed for P detection by synchrotron-based X-ray fluorescence microscopy (XFM). It differs from the conventional DGT BL as the hydrogel is eliminated to overcome the issue that the fluorescent X-rays of P are detected mainly from shallow sample depths. Instead, the novel design is based on a polyimide film (Kapton) onto which finely powdered titanium dioxide-based P binding agent (Metsorb) was applied, resulting in superficial P binding only. The BL was successfully used for quantitative visualization of P diffusion from three conventional P fertilizers applied to two soils. On a selection of samples, XFM analysis was confirmed by quantitative laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The XFM method detected significant differences in labile P concentrations and P diffusion zone radii with the P fertilizer incubation, which were explained by soil and fertilizer properties. This development paves the way for fast XFM analysis of P on large DGT BLs to investigate in situ diffusion of labile P from fertilizers and to visualize large-scale P cycling processes at high spatial resolution.

Selenium in plant-based beverages: Total content, estimated bioaccessibility and contribution to daily intake.

BACKGROUND: The search for alternative protein sources has increased the consumption and commercialization of plant-based beverages (PBBs). This study aimed to determine the total Se content, estimate the bioaccessibility of selenium (Se) in commercial PBBs derived from different raw materials, and evaluate their contribution to the reference daily intake (RDI). METHODS: An ultrasound assisted acid digestion method and ICP-MS was used to determine Se, and the INFOGEST method to estimate the bioaccessible percentages. Validation of this method was also performed, and the parameters obtained were: LOD and LOQ were 2.1 and 4.0 µg/kg, respectively. For accuracy, recovery percentages ranged from 99 % and 111 % (certified reference materials), and 95 % and 101 % (spiked experiments for bioaccessible extracts as recoveries). RESULTS: The PBBs presented total Se content between 4 and 226 µg/kg. Bioaccessible percentages ranged from 63.5 % (mix of plant sources) to 95.9 % (produced with organic cashew nuts). Only one cashew nut PBBs supplied the daily demand of Se, representing 64.6 %, 75.3 % and 82.2 % of the RDI; for lactating and pregnant women, children (≥ 4 years) and adults, respectively. CONCLUSIONS: The Se determination method through acid digestion assisted by ultrasound and ICP-MS was considered adequate for the PBBs samples. Se content varied according to the raw material used in sample preparation. High percentages (> 60 %) of bioaccessibility were observed and only one PBBs derived from organic cashew nuts supplied the recommended Se demand for different groups of individuals.

Landfill fire impact on bee health: beneficial effect of dietary supplementation with medicinal plants and probiotics in reducing oxidative stress and metal accumulation.

The honey bee is an important pollinator insect susceptible to environmental contaminants. We investigated the effects of a waste fire event on elemental content, oxidative stress, and metabolic response in bees fed different nutrients (probiotics, Quassia amara, and placebo). The level of the elements was also investigated in honey and beeswax. Our data show a general increase in elemental concentrations in all bee groups after the event; however, the administration of probiotics and Quassia amara help fight oxidative stress in bees. Significantly lower concentrations of Ni, S, and U for honey in the probiotic group and a general and significant decrease in elemental concentrations for beeswax in the probiotic group and Li in the Quassia amara group were observed after the fire waste event. The comparison of the metabolic profiles through pre- and post-event PCA analyses showed that bees treated with different feeds react differently to the environmental event. The greatest differences in metabolic profiles are observed between the placebo-fed bees compared to the others. This study can help to understand how some stress factors can affect the health of bees and to take measures to protect these precious insects.

Effect of graded levels of selenium supplementation as selenite on expression of selenosugars, selenocysteine, and other selenometabolites in rat liver.

Using high pressure liquid chromatography (HPLC) coupled with selenium-specific inductively coupled plasma mass spectrometry (ICP-MS) and molecule specific (Orbitrap MS/MS) detection, we previously found that far more selenium (Se) is present as selenosugar (seleno-N-acetyl galactosamine) in Se-adequate turkey liver than is present as selenocysteine (Sec) in true selenoproteins, and that selenosugars account for half of the Se in high-Se turkey liver. To expand these observations to mammals, we studied Se metabolism in rats fed graded levels of selenite from 0 to 5 µg Se/g for 4 wk. In Se-adequate (0.24 µg Se/g) rats, 43% of liver Se was present as Sec, 32% was present as selenosugars, and 22% as inorganic Se bound to protein. In liver of rats fed 5 µg Se/g as selenite, the quantity of Sec remained at the Se-adequate plateau (11% of total Se), 22% was present as low molecular weight (LMW) selenosugars with substantial additional selenosugars linked to protein, but 64% was present as inorganic Se bound to protein. No selenomethionine was found at any level of selenite supplementation. Below the Se requirement, Se is preferentially incorporated into Sec-selenoproteins. Above the dietary Se requirement, selenosugars become by far the major LMW water soluble Se species in liver, and levels of selenosugar-decorated proteins are far higher than Sec-selenoproteins, making these selenosugar-decorated proteins the major Se-containing protein species in liver with high Se supplementation. This accumulation of selenosugars linked to cysteines on proteins or the build-up of inorganic Se bound to protein may underlie Se toxicity at the molecular level.

Selenomethionine supplementation and expression of selenosugars, selenocysteine, and other selenometabolites in rat liver.

Selenomethionine (SeMet) as a methionine analog can be incorporated into protein. In turkeys, we recently found that selenium (Se) as selenite is not metabolized to SeMet but rather to selenosugars (seleno-N-acetyl galactosamine) bound to protein as well as to selenocysteine (Sec) in selenoproteins. To characterize the metabolism of SeMet, we fed rats graded levels of SeMet from 0 to 5 µg Se/g in a Se-deficient diet for 4 wk, and investigated the fate and accumulation of liver Se using high pressure liquid chromatography (HPLC) coupled with Se-specific inductively coupled plasma mass spectrometry (ICP-MS) and molecule specific (Orbitrap MS/MS) detection. Up to 0.24 µg Se/g (Se requirement for maximal glutathione peroxidase activity), Sec accounted for ∼40% of total liver Se whereas SeMet only accounted for 3-11%. Analysis of water-soluble extracts found negligible low molecular weight (LMW) Se species in rats fed 0 and 0.08 µg Se/g, including no SeMet. At 0.24 µg Se/g and above, SeMet accounted for only 10% of LMW Se species, whereas methyl- and glutathionyl-selenosugars accounted for 70% of LMW Se species. Above the Se requirement, SeMet was ∼30% of the proteinaceous amino acids, whereas Sec levels fell to 5% in rats fed 5 µg Se/g as SeMet. Last, considerably less inorganic Se was bound to liver protein with high SeMet as compared to selenite in a parallel study. SeMet is efficiently metabolized and mixes with the common Se metabolite pool, where Se is preferentially incorporated into Sec and Sec-selenoproteins until selenoproteins plateau; with high SeMet intake, Se is increasingly accumulated as LMW selenosugars and as selenosugar-decorated proteins.

Simultaneous speciation analysis of Hg and Se in fish by high-performance liquid chromatography and inductively coupled plasma-mass spectrometry following microwave-assisted enzymatic hydrolysis.

This study reports the development and validation of a new analytical method for simultaneous speciation analysis of Se and Hg in fish muscle. For this purpose, four Se species (selenite/Se(IV), selenate/Se(VI), selenomethionine/SeMet, and selenocysteine/SeCys) and two Hg species (inorganic mercury/iHg and methylmercury/MeHg) were extracted simultaneously by microwave-assisted enzymatic hydrolysis and then separated by HPLC in less than 15 min by using a column with both anion and cation exchange mechanisms and a mobile phase consisting of a mixture of methanol 5% (v/v), 45 mM HNO3, 0.015% 2-mercaptoethanol, and 1.5 mM sodium 3-mercapto-1-propanesulfonate. The separated species of Hg and Se were detected online by inductively coupled plasma-mass spectrometry (ICP-MS). The speciation analysis method was validated by means of the accuracy profile approach by carrying out three series of measurements in duplicate on three different days over a time-span of 3 weeks. The limits of quantification (LOQ) are in the range of 0.010-0.013 mg/kg wet weight (ww) for all selenium species, except for Se(IV) (0.15 mg/kg ww), while the coefficient of variation in terms of intermediate reproducibility (CVR) was < 7%. The LOQ for MeHg was 0.006 mg/kg ww, while the CVR was 3%. The method was successfully applied to the analysis of muscle samples from four different fish species: rainbow trout, tuna, swordfish, and dogfish.

Development and validation of a simple microwave-assisted digestion sample preparation technique for the estimation of aluminium and magnesium in a few pharmaceutical dosage forms by an inductively coupled-mass spectrometer (ICP-MS).

Rationale: A simple, sensitive, reliable, validated, inductively coupled plasma mass spectrometric method for the determination of aluminium and magnesium using a simple common microwave-assisted digestion sample preparation technique for a few commonly used formulations was developed and validated according to International Conference on Harmonization Q3D and the United States Pharmacopeia general chapter <232> and <233>. The following pharmaceutical dosage forms were considered for estimation of aluminium and magnesium: Alumina, magnesia simethicone oral suspension, Alumina, magnesia simethicone chewable tablets, alumina and magnesia oral suspension, alumina and magnesium carbonate oral suspension. Methods: The methodology included optimizing a common microwave assisted digestion method, selecting the isotopes, choosing the measurement technique, and designating internal standards. The finalized microwave assisted procedure was a two-step program where in the first step the samples were ramped for 10 min to a temperature of 180 °C and hold for 5 min followed by ramping for 10 min to a temperature of 200 °C and hold for 10 min. Magnesium (24Mg) and aluminium (27Al) isotopes were finalized, internal standard assigned for both the isotopes was yttrium (89Y) with Helium (kinetic energy discrimination-KED) as the measuring mode. System suitability was run before initiating analysis to ensure that system performance was consistent. Results: Analytical validation parameters like specificity, linearity (from 25% to 200% of sample concentration), the detection limit and the limit of quantification were established. For all these dosage forms, the method's precision was demonstrated by analyzing the percentage relative standard deviation for six injections. Accuracy was established from 50% to 150% of instrument working concentration (J-levels) for aluminium and magnesium for all the formulations and was found to be within the range of 90-120%. Conclusion: This common analysis method, along with the common microwave-digestion technique applies to numerous types of matrices for a finished dosage form with aluminium and magnesium.

Alzheimer's Disease and Age-Related Changes in the Cu Isotopic Composition of Blood Plasma and Brain Tissues of the APPNL-G-F Murine Model Revealed by Multi-Collector ICP-Mass Spectrometry.

Alzheimer's' disease (AD) is characterized by the formation of ß-amyloid (Aß) plaques and neurofibrillary tangles of tau protein in the brain. Aß plaques are formed by the cleavage of the ß-amyloid precursor protein (APP). In addition to protein aggregations, the metabolism of the essential mineral element Cu is also altered during the pathogenesis of AD. The concentration and the natural isotopic composition of Cu were investigated in blood plasma and multiple brain regions (brain stem, cerebellum, cortex, and hippocampus) of young (3-4 weeks) and aged (27-30 weeks) APPNL-G-F knock-in mice and wild-type controls to assess potential alterations associated with ageing and AD. Tandem inductively coupled plasma-mass spectrometry (ICP-MS/MS) was used for elemental analysis and multi-collector inductively coupled plasma-mass spectrometry (MC-ICP-MS) for high-precision isotopic analysis. The blood plasma Cu concentration was significantly altered in response to both age- and AD-related effects, whereas the blood plasma Cu isotope ratio was only affected by the development of AD. Changes in the Cu isotopic signature of the cerebellum were significantly correlated with the changes observed in blood plasma. The brain stem showed a significant increase in Cu concentration for both young and aged AD transgenic mice compared with healthy controls, whereas the Cu isotopic signature became lighter as a result of age-related changes. In this work, ICP-MS/MS and MC-ICP-MS provided relevant and complementary information on the potential role of Cu in ageing and AD.

Assessment of the Concentration of 51 Elements in the Liver and in Various Parts of the Human Brain-Profiling of the Mineral Status.

The anthropogenic environment and diet introduce many metals into the human body, both essential and toxic. Absorption leads to systemic exposure and accumulation in body fluids and tissues. Both excess and deficiency of trace elements are health hazards. The primary aim of the present study was to evaluate the concentration of 51 elements in liver samples and 11 selected brain regions obtained at post-mortem examination from a population of adults living in south-eastern Poland (n = 15). A total of 180 analyses were performed by inductively coupled plasma mass spectrometry in two independent replicates. The collected data show very high individual variability in the content of the investigated elements. Macroelements such as sodium, magnesium, phosphorus, potassium, calcium, iron, and zinc occurred in the highest concentrations and with the greatest statistically significant variations. Although the elemental content of the brain and liver differed significantly, the strongest positive correlation between liver and polus frontalis was observed for the essential element selenium (0.9338) and the strongest negative one for manganese (-0.4316) and lanthanum (-0.5110). The brain areas studied have different requirements for phosphorus, manganese, iron, and molybdenum. In addition, males had a significantly (p < 0.05) higher brain content of lanthanides and actinides than females. The results of this study show that the inhabitants of south-eastern Poland are exposed to a fairly uniform accumulation of aluminum and vanadium in the brain, which have the highest affinity to the thalamus dorsalis. This result proves that there is environmental exposure to these elements.

Mineral, trace element, and toxic metal concentration in hair from dogs with idiopathic epilepsy compared to healthy controls.

BACKGROUND: Altered trace element status is associated with epilepsy in humans and dogs with idiopathic epilepsy (IE). OBJECTIVES: Compare hair element concentrations in epileptic and healthy dogs. ANIMALS: Sixty-three dogs with IE (53 treated, 10 untreated) and 42 controls. METHODS: Case-control study using ICP-MS to determine hair calcium, magnesium, phosphorus, sodium, potassium, iron, copper, manganese, zinc, selenium, chromium, lead, mercury, cadmium, arsenic, aluminum, and nickel concentration. Groups were compared using nonparametric tests. Results were controlled for diet, sex, age, and hair color using generalized linear mixed models. RESULTS: Compared to healthy controls, dogs with IE had lower hair phosphorus (mean ± SD; IE: 286.19 ± 69.62 µg/g, healthy: 324.52 ± 58.69 µg/g; P = .001), higher hair copper (IE: 10.97 ± 3.51 µg/g, healthy: 8.41 ± 1.27 µg/g; P < .001), zinc (IE: 158.25 ± 19.64 µg/g, healthy: 144.76 ± 32.18 µg/g; P < .001), copper/zinc ratio (IE: 0.07 ± 0.02, healthy: 0.06 ± 0.01; P = .003), selenium (IE: 1.65 ± 0.43 µg/g, healthy: 0.94 ± 0.73 µg/g; P < .001), and arsenic (IE: 0.40 ± 0.78 µg/g, healthy: 0.05 ± 0.08 µg/g; P < .001). When comparing treated and untreated epileptic dogs with healthy dogs, the differences in phosphorus and selenium remained significant for both groups, whereas the differences in copper, zinc, and arsenic were significant only for treated dogs. Potassium bromide treatment was strongly associated with high hair arsenic (P = .000). CONCLUSIONS AND CLINICAL IMPORTANCE: Altered trace element status could be involved in the pathophysiology of IE in dogs. Antiseizure drugs might affect trace element and arsenic metabolism.