Selenium increases antimony uptake in ramie (Boehmeria nivea L.) by enhancing the physiological, antioxidative, and ionomic mechanisms

Ramie (Boehmeria nivea L.) is a promising phytoremediation candidate due to its high tolerance and enrichment capacity for antimony (Sb). However, challenges arise as Sb accumulated mainly in roots, complicating soil extraction. Under severe Sb contamination, the growth of ramie may be inhibited. Strategies are needed to enhance Sb accumulation in ramie's aboveground parts and improve tolerance to Sb stress. Considering the beneficial effects of selenium (Se) on plant growth and enhancing resistance to abiotic stresses, this study aimed to investigate the potential use of Se in enhancing Sb uptake by ramie. We investigated the effects of Se (0.5, 1, 2, 5, or 10 μM) on ramie growth, Sb uptake and speciation, antioxidant responses, and ionomic profiling in ramie under 10 mg/L of SbIII or antimonate (SbV) stresses. Results revealed that the addition of 0.5 μM Se significantly increased shoot biomass by 75.73% under SbIII stress but showed minimal effects on shoot and root length in both SbIII and SbV treatments. Under SbIII stress, 2 μM Se significantly enhanced Sb concentrations by 48.42% in roots and 62.88% in leaves. In the case of SbV exposure, 10 μM Se increased Sb content in roots by 42.57%, and 1 μM Se led to a 91.74% increase in leaves. The speciation analysis suggested that Se promoted the oxidation of SbIII to less toxic SbV to mitigate Sb toxicity. Additionally, Se addition effectively minimized the excess reactive oxygen species produced by Sb exposure, with the lowest malondialdehyde (MDA) content at 0.5 μM Se under SbIII and 2 μM Se under SbV, by activating antioxidant enzymes including superoxide dismutase, catalase, peroxidase, and glutathione peroxidase. Ionomic analysis revealed that Se helped in maintaining the homeostasis of certain nutrient elements, including magnesium, potassium (K), calcium (Ca), iron (Fe), and copper (Cu) in the SbIII-treated roots and K and manganese (Mg) in the SbV-treated roots. The results suggest that low concentrations of Se can be employed to enhance the phytoremediation of Sb-contaminated soils using ramie.

Association of Magnesium, Iron, Copper, and Zinc Levels with the Prevalence of Behavior Problems in Children and Adolescents

Magnesium (Mg), iron (Fe), copper (Cu), and zinc (Zn) are indispensable elements in children's growth and development. However, epidemiological evidence regarding essential elements and their mixed exposure to behavior problems remains in its infancy. The objective of the present study was to evaluate the association between essential elements and the manifestation of behavior problems, with an additional focus on the implications of their mixture. An electronic medical records review was performed among 4122 subjects aged 6-18 years who underwent examinations at Children's Hospital, Zhejiang University School of Medicine, between January 2019 and July 2022. The concentrations of essential elements were measured by atomic absorption spectrometry, and behavior problems were assessed by using the Conners' Parent Rating Scale (CPRS). A total of 895 (21.7%) children and adolescents were identified as having behavior problems. For single exposure, inversely linear dose-response relationships were identified between continuous Mg and Zn levels and the prevalence of behavior problems, and the prevalence ratios (PRs) in the categorical lowest tertile were 1.28 (95% confidence interval, CI: 1.07-1.54) for Mg and 1.31 (95% CI: 1.05-1.63) for Zn compared to the highest tertile. For mixture exposure, an inverse association between essential elements and behavior problems was also found, mainly contributed by Mg (posterior inclusion probability, PIP = 0.854). Whole blood levels of Mg and Zn were significantly inversely associated with behavior problems. The findings highlight the pivotal role of essential elements in behavior problems and emphasize the importance of maintaining adequate levels of essential elements during children's maturation.

Uptake, tolerance, and detoxification mechanisms of antimonite and antimonate in Boehmeria nivea L

Boehmeria nivea L. (ramie) is a promising phytoremediation plant for antimony (Sb)-contaminated soils. However, the uptake, tolerance, and detoxification mechanisms of ramie to Sb, which are the basis for finding efficient phytoremediation strategies, remain unclear. In the present study, ramie was exposed to 0, 1, 10, 50, 100, and 200 mg/L of antimonite (Sb(III)) or antimonate (Sb(V)) for 14 days in hydroponic culture. The Sb concentration, speciation, subcellular distribution, and antioxidant and ionomic responses in ramie were investigated. The results illustrated that ramie was more effective in the uptake of Sb(III) than Sb(V). Most of the Sb accumulated in ramie roots, with the highest level reaching 7883.58 mg/kg. Sb(V) was the predominant species in leaves, with 80.77-96.38% and 100% in the Sb(III) and Sb(V) treatments, respectively. Immobilization of Sb on the cell wall and leaf cytosol was the primary mechanism of accumulation. Superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) contributed significantly to root defense against Sb(III), while CAT and glutathione peroxidase (GPX) were the major antioxidants in leaves. CAT and POD played crucial roles in the defense against Sb(V). B, Ca, K, Mg, and Mn in Sb(V)-treated leaves and K and Cu in Sb(III)-treated leaves may be related to the biological processes of Sb toxicity mitigation. This study is the first to investigate the ionomic responses of plants toward Sb and could provide valuable information for the phytoremediation of Sb-polluted soils.

New insights into the role of metal(loid)s in the development of ulcerative colitis: a systematic review

The relationship between heavy metals and ulcerative colitis (UC) was investigated in several studies, but their results were not consistent. Therefore, in this systematic review study, the positive and negative effects of metal(loid)s (Zn, Cu, Fe, Se, Pb, Ni, and As) on UC disease were investigated. In this systematic search, 13 original articles from 1993 to 2021 were identified in Google Scholar, Science Direct, Scopus, PubMed, and the Web of Science databases. In included studies, the concentrations of heavy metals and essential elements were measured in the blood, serum, intestinal biopsies, and hair samples of the patients. Some studies have also examined the heavy metal concentration in UC patients' diet and their drinking water. In the serum samples, Pb (220 ± 108 mg/L) and Cu (401.5 ± 104 µg/L) had the maximum concentrations among the other elements, as well as Zn and Fe had the highest levels in hair and intestinal tissue samples, respectively. In light of the selected articles, there is a possibility of a preventive role for Se and Zn in UC development. Moreover, exposure to Fe can exacerbate the symptoms of the disease. In conclusion, this review reveals that toxic metals, as ubiquitous environmental pollutants, can contribute to the exacerbation of inflammatory intestinal symptoms, and consumption of essential elements can play a vital role in the control of UC, and it is important to pay attention to them in health decisions.

Fulvic acid-like substance-Ca(II) complexes improved the utilization of calcium in rice: Chelating and absorption mechanism

Water-soluble chelated calcium has been widely used in agriculture as a fertilizer to improve the absorption and utilization of calcium by plants. This paper prepared a new organic mineral fertilizer, based on fulvic acid-like substance chelated calcium (PFA-Ca²⁺ complex), using optimal parameters (i.e., pH, time, temperature, and Ca²⁺ concentration) to achieve a high chelation efficiency. The absorption, utilization, and distribution of the PFA-Ca²⁺ complex in rice roots were analyzed using laser scanning confocal microscopy (LSCM). Our results demonstrated that the optimal PFA-Ca²⁺ complex chelating efficiency (87%) was achieved at an initial Ca²⁺ concentration of 0.1 mol L^-1, an equilibration time of 120 min, a pH of 5.0, and a temperature of 40 °C. The chelating reaction of a fulvic acid-like substance with Ca²⁺ primarily occurred on phenol hydroxyl, alcohol hydroxyl, and carboxyl groups. The PFA-Ca²⁺ complex was primarily enriched in the roots' pericycle, cortical, and epidermis cells, in both chelating and non-chelating forms. To our knowledge, this is the first report investigating how the PFA-Ca²⁺complex affects transformation in plants, which has significant implications for research on plant nutrition and nutrient distribution.

Disordered serum essential element levels are associated with increased risk of kidney tumors

Essential elements play vital roles in the regulation of carcinogenesis. We aimed to investigate the relationship between essential elements and kidney tumors. This study included 72 healthy individuals and 100 kidney tumor patients. The concentrations of cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), selenium (Se), and zinc (Zn) were determined by inductively coupled plasma mass spectrometry. The random forest model was used to evaluate the importance of each variable by using the randomForest package. The associations between essential elements and clinical tumor characteristics were examined by the Mann-Whitney U-test, and the log-rank test was used to assess the Kaplan-Meier curves. The levels of Co, Cr, Fe, Mn, Ni, and Zn in patients with kidney tumors were significantly lower. In the random forest model, the top two metallic features were Co and Zn. The Kaplan-Meier curve showed that patients with lower Co, Se, and Zn levels exhibited lower progression-free survival. In summary, this study gathered evidence that disordered essential elements are associated with kidney tumors and thus opens a new path to elucidate the etiology of kidney tumors from the perspective of environmental health and safety.

Molybdenum: More than an essential element

Molybdenum (Mo) is an essential element for almost all living organisms. After being taken up into the cells as molybdate, it is incorporated into the molybdenum cofactor, which functions as the active site of several molybdenum-requiring enzymes and thus plays crucial roles in multiple biological processes. The uptake and transport of molybdate is mainly mediated by two types of molybdate transporters. The homeostasis of Mo in plant cells is tightly controlled, and such homeostasis likely plays vital roles in plant adaptation to local environments. Recent evidence suggests that Mo is more than an essential element required for plant growth and development; it is also involved in local adaptation to coastal salinity. In this review, we summarize recent research progress on molybdate uptake and transport, molybdenum homeostasis network in plants, and discuss the potential roles of the molybdate transporter in plant adaptation to their local environment.

Metal and essential element concentrations during pregnancy and associations with autism spectrum disorder and attention-deficit/hyperactivity disorder in children

BACKGROUND

Prenatal exposure to toxic metals or variations in maternal levels of essential elements during pregnancy may be a risk factor for neurodevelopmental disorders such as attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in offspring.

OBJECTIVES

We investigated whether maternal levels of toxic metals and essential elements measured in mid-pregnancy, individually and as mixtures, were associated with childhood diagnosis of ADHD or ASD.

METHODS

This study is based on the Norwegian Mother, Father and Child Cohort Study and included 705 ADHD cases, 397 ASD cases and 1034 controls. Cases were identified through linkage with the Norwegian Patient Registry. Maternal concentrations of 11 metals/elements were measured in blood at week 17 of gestation; cadmium; cesium; cobalt; copper; lead; magnesium; manganese; selenium; zinc; total arsenic; and total mercury. Multivariable adjusted logistic regression models were used to examine associations between quartile levels of individual metals/elements and outcomes. We also investigated non-linear associations using restricted cubic spline models. The joint effects of the metal/element mixture on ASD and ADHD diagnoses were estimated using a quantile-based g-computation approach.

RESULTS

For ASD, we identified positive associations (increased risks) in the second quartile of arsenic [OR = 1.77 (CI: 1.26, 2.49)] and the fourth quartiles of cadmium and manganese [OR = 1.57 (CI: 1.07 2.31); OR = 1.84 (CI: 1.30, 2.59)], respectively. In addition, there were negative associations between cesium, copper, mercury, and zinc and ASD. For ADHD, we found increased risk in the fourth quartiles of cadmium and magnesium [OR = 1.59 (CI: 1.15, 2.18); [OR = 1.42 (CI: 1.06, 1.91)]. There were also some negative associations, among others with mercury. In addition, we identified non-linear associations between ASD and arsenic, mercury, magnesium, and lead, and between ADHD and arsenic, copper, manganese, and mercury. There were no significant findings in the mixture approach analyses.

CONCLUSION

Results from the present study show several associations between levels of metals and elements during gestation and ASD and ADHD in children. The most notable ones involved arsenic, cadmium, copper, mercury, manganese, magnesium, and lead. Our results suggest that even population levels of these compounds may have negative impacts on neurodevelopment. As we observed mainly similarities among the metals' and elements' impact on ASD and ADHD, it could be that the two disorders share some neurochemical and neurodevelopmental pathways. The results warrant further investigation and replication, as well as studies of combined effects of metals/elements and mechanistic underpinnings.

Tissue concentrations of Fe, Zn, Cu and Mn of four Taiwanese toothed cetaceans

Concentrations of Fe, Mn, Zn, and Cu in the muscle, lung, liver, and kidney tissues of 49 cetaceans, including 11 Kogia sima (Ks), 10 Lagenodelphis hosei (Lh), 14 Grampus griseus (Gg), and 14 Stenella attenuata (Sa) from 1994 to 2012 in Taiwan were measured. Ks exhibited the highest Fe, and the lowest Zn, Cu and Mn tissue concentrations. The Kogiid and Delphinid groups were significantly categorized by nMDS analysis. Fe muscle concentrations were found to be positively correlated with Ks, Lh, and Gg but not Sa body length. The different levels of Zn-, Cu-, and Mn- tissue concentrations of the two families were due to their different SOD systems. Their calves contained higher Cu liver concentrations. The four essential elements in cetaceans regulate homeostasis to meet their eco-physiological demand. The baseline levels for these four elements in these four tissues in the Delphinid group are defined.

Comparison of aqueous and enzymatic extraction combination with sequential filtration for the profiling of selected trace elements in medicinal plants from Kenya

This work presents results for the profiling of eight essential elements (Co, Cu, Ni, V, Mo, Mn, Zn and Cr) in aqueous and enzymatic extracts of eight anti-diabetic medicinal plants, used by Traditional Medicine Practitioners from Nyamira County, Kenya determined by ICP-MS. The plants used in the study were Solanum indicum, Plectranthus barbatus, Ultrica dioica, Bidens pilosa, Solanum mauense, Clerodendrum myricoides, Carissa edulis and Aloe vera. A sequential filtration procedure was applied to fractionate the elemental contents of the obtained aqueous extracts into molecular size fractions. The results indicate that the low molecular size species (<3 kDa) were predominant for Mo, Zn, Ni, Co, Mn and Cu, while the moderately large species (10 kDa-0.45 μm) of V were predominant in most of the medicinal plant extracts. In addition enzymatic extraction was compared to aqueous extraction to study the effect of the gastric and intestinal conditions on the release of selected elements from the plants. The amount of the elements extracted by the gastric phase enzymes was higher than the amount extracted by the intestinal phase enzymes. In general, the determined elemental amounts of enzymatic extractions were higher than those of corresponding water extractions for 70% of the elements studied.

The effect of vanadium on essential element uptake of Setaria viridis' seedlings

High concentrations of vanadium, a ubiquitous element in the environment, in growing media leads to deformation of root structure and leaf chlorosis and necrosis, consequently affecting the translocations of nutrients and essential elements. However, the effects of vanadium on essential element uptake, and the interactions of essential elements in the presence of vanadium, remain incompletely understood. To elucidate the effects of different concentrations of vanadium on major and trace essential elements and plant growth, a native plant species growing in a vanadium mining area, Setaria viridis (dog tail's grass), was incubated in solutions containing 0-55.8 mg/L vanadium. The shoot accumulation of four major essential elements and five trace essential elements was detected, and the root length and stem height were measured. The results showed that vanadium in soil solution enhanced the accumulation of all major essential elements in shoot. Vanadium concentrations lower than 47.4 mg/L showed an obvious positive (p < 0.05) effect on P accumulation and translocation. In the case of trace essential elements, there were threshold values for solution vanadium stimulation of element uptake. The threshold values for Cu and Zn, Fe, and Mo uptake were 4.3, 16.3, and 40.6 mg/L, respectively. When vanadium levels surpassed these values, accumulation was suppressed and the solution vanadium concentrations attenuated the solution-to-shoot translocation of most of the essential elements. Among the trace essential elements, translocation of Fe was obviously enhanced (p < 0.05) by vanadium. Solution vanadium also enhanced plant growth at lower concentrations and inhibited it at higher levels. The threshold values for stem height and root length were 36.8 and 16.3 mg/L, respectively. Concentrations of 40 and 55.8 mg/L vanadium in soil solution caused a 50% decrease in root length and stem height, respectively, showing that root length of Setaria viridis is more susceptible to vanadium toxicity than stem growth.

Use of human milk in the assessment of toxic metal exposure and essential element status in breastfeeding women and their infants in coastal Croatia

Pregnant and lactating women and infants are vulnerable population groups for adverse effects of toxic metals due to their high nutritional needs and the resultant increased gastrointestinal absorption of both, essential and toxic elements. Although breastfeeding is recommended for infants worldwide, as human milk is the best source of nutrients and other required bioactive factors, it is also a pathway of maternal excretion of toxic substances including toxic metals and thus a source of infant exposure. The aim of this research was to assess health risks in breastfeeding women in the coastal area of the Republic of Croatia and their infants (N=107) due to maternal exposure to Cd and Pb via cigarette smoking, and Hg via seafood and dental amalgam fillings, and their interaction with essential elements. Biological markers of exposure were the concentrations of main toxic metals Pb, Cd and Hg in maternal blood and three types of breast milk throughout lactation stages. Biological markers of effects were the levels of essential elements Ca, Fe, Cu, Zn and Se in maternal serum and breast milk. With regard to cigarette smoking as a source of exposure to Cd and Pb, there were effects of smoking on Cd concentration in blood and correlations between the smoking index and Cd concentrations in maternal blood (ρ=0.593; P<0.001) and mature milk (ρ=0.271; P=0.011) and Pb concentration in transitional milk (ρ=0.280; P=0.042). Regarding fish, we found correlations between weekly consumption frequency and total Hg concentrations in maternal blood (ρ=0.292; P=0.003) and mature milk (ρ=0.303; P=0.003). The number of dental amalgam fillings correlated with total Hg concentrations in colostrum (ρ=0.489; P=0.005) and transitional milk (ρ=0.309; P=0.018). As for the essential element status, only Se levels in maternal serum decreased by 10% in persons who continued smoking during pregnancy compared to non-smokers. In conclusion, the levels of main toxic metals Cd, Pb and Hg and essential elements Ca, Fe, Cu, Zn and Se in maternal blood and three types of breast milk samples in the studied area of coastal Croatia showed no risk of disrupted essential element levels with regard of toxic metal exposure in both breastfeeding women and their infants.

Blood lead level and its relationship to essential elements in preschool children from Nanning, China

OBJECTIVE

Our study aimed to assess the distribution of blood lead level and its relationship to essential elements in preschool children in an urban area of China.

DESIGN AND METHODS

A total of 6741 children aged 0- to 6-year-old were recruited. Levels of lead, zinc, copper, iron, calcium, and magnesium in whole blood samples were determined using atomic absorption spectrometry.

RESULTS

The mean blood lead level (BLL) and the prevalence of BLL≥10μg/dl (5.26±4.08μg/dl and 6.84%, respectively) increased with age gradually, and there was a gender-difference for blood lead, copper, zinc and iron levels. Compared with the group of children who had BLLs<5μg/dl, the groups of 5≤BLLs<10μg/dl and 10≤BLLs<15μg/dl showed higher blood zinc, iron and magnesium levels, and a lower blood calcium level. A positive correlation of lead with zinc, iron and magnesium, and a negative correlation of lead with calcium were found in the group of children with BLL<5μg/dl.

CONCLUSION

Age- and gender-differences were found when assessing the BLL and intoxication prevalence in preschool children. Metabolic disorder of essential elements was found even with a low level of lead exposure.

Determination of essential and toxic elements in Hungarian honeys

The aim of this present study was determination of essential and toxic element concentrations in 34 mono- and multi-floral honey samples from four geographical regions of Hungary, and examination of the connection between the floral origin and the element content. Ten elements (Al, Ca, Cu, Fe, K, Mg, Mn, P, S and Zn) were identified by ICP-OES and six (As, Cd, Cr, Mo, Pb, Se) were analysed by ICP-MS. Potassium, calcium, and phosphorus were the most abundant elements with mean concentrations of 372, 47.9 and 44.3 mg kg(-1), respectively. The essential element content was very low in the analysed samples and generally below literature values. The concentrations of toxic elements were sufficiently low as to pose no risk to human health. The concentrations of aluminium, arsenic, cadmium and lead were low, with mean concentrations of 1028, 15.6, 0.746 and 45.5 μg kg(-1), respectively. Three honey groups (acacia, rape and sunflower) were distinguished by linear discriminant analysis from their element content.