Tissue Zinc Research Articles

Concentrations of Essential Trace Metals in the Brain of Animal Species-A Comparative Study.

The essential trace metals iron, zinc, and copper have a significant physiological role in healthy brain development and function. Especially zinc is important for neurogenesis, synaptogenesis, synaptic transmission and plasticity, and neurite outgrowth. Given the key role of trace metals in many cellular processes, it is important to maintain adequate levels in the brain. However, the physiological concentration of trace metals, and in particular zinc, in the human and animal brain is not well described so far. For example, little is known about the trace metal content of the brain of animals outside the class of mammals. Here, we report the concentration of iron, zinc, and copper in fresh brain tissue of different model-species of the phyla Chordata (vertebrates (mammals, fish)), Annelida, Arthropoda (insects), and Mollusca (snails), using inductively coupled plasma mass-spectrometry (ICP-MS). Our results show that the trace metals are present in the nervous system of all species and that significant differences can be detected between species of different phyla. We further show that a region-specific distribution of metals within the nervous system already exists in earthworms, hinting at a tightly controlled metal distribution. In line with this, the trace metal content of the brain of different species does not simply correlate with brain size. We conclude that although the functional consequences of the controlled metal homeostasis within the brain of many species remains elusive, trace metal biology may not only play an important role in the nervous system of mammals but across the whole animal kingdom.

Comparison of tissue level of selenium and zinc in patients with nasal polyposis and healthy people

BackgroundNasal polyposis (NP) is an inflammatory condition in nasal and paranasal sinus cavities and its pathophysiology is poorly understood. It seems likely that the trace elements such as zinc and selenium may play a critical role in the genesis of inflammatory sinonasal disease. ObjectivesThe aim of this study was to investigate the role of these elements in NP and compare these findings with normal nasal mucosa. Methods & materialsIn this descriptive-analytic cross-sectional study which was done at Imam Khomeini hospital of Ahvaz between July 2018 and June 2019, selenium and zinc levels measured in polyp tissues of 72 patients (47 men and 25 women) and were compared with healthy nasal mucosa of 36 control cases (15 men and 21 women). Hydride generation and flame atom absorption spectroscopy were utilized for selenium and zinc quantifications, consequently. ResultsThe mean tissue zinc and selenium levels were, respectively, 18.569 μg/g and 68.65 ng/g in patients group and 71.015 μg/g, 249.53 ng/g in control group. It was found that the concentrations of zinc element were significantly lower in polyp tissues than healthy nasal mucosa. In the case of selenium no significant difference was found between patients and controls. ConclusionTrace elements are undoubtedly useful, and further studies are needed to determine the effect of zinc and selenium on nasal and sinus polyps.

Effect of type of compost and application rate on growth and quality of lettuce plant

This study intends to assess the effect of compost types and rates on lettuce growth. A pot experiment was conducted at the greenhouse of the College of Agriculture and Veterinary Medicine experimental station, Saudi Arabia. Three types (chicken residues, animal residues, and mixed organic residues) and four rates (1%, 2%, 4%, and 6%) were added to sandy soil. Lettuce seeds were sown in a nursery. After two weeks, each seedling was transplanted to a pot that contained 15 kg of soil. The lettuce plants were irrigated regularly for 60 days, then harvested following dry weight (DW) and chemical analyses. The results showed great variation in the DW, nutrient content, and heavy metals concentrations between the different compost treatments. It noted that DW of lettuce decreased with increasing rates of compost in certain treatments. Moreover, no plant growth occurred in some treatments derived from the mixed organic residue with higher application rates. The nutrient status of lettuce tissues varies greatly among different types of compost. The concentration of heavy metals and microelements present within the lettuce tissues was significantly affected by the types of compost. Copper (Cu), Zinc (Zn), Lead (Pb), Cadmium (Cd), and Nickel (Ni) concentrations in lettuce tissues ranged between 7.4 and 9.6, 81.5 and 104, 23.3 and 28.2, 3.7 and 5.8, and 27 and 30 mg kg−1, respectively. It revealed that heavy metals concentration increased in lettuce tissues with an increasing application rate of composts. The content of Zn, Pb, Cd, and Ni in lettuce plants were higher and did not meet the requirement set by national standards.

Long-Term Phenotypic and Proteomic Changes Following Vitrified Embryo Transfer in the Rabbit Model.

Simple SummaryThis study was conducted to demonstrate how a vitrified embryo transfer procedure incurs phenotypic and molecular changes throughout life. This study reports the first evidence describing that embryonic manipulation during a vitrified embryo transfer cycle induced molecular modifications, concerning oxidative phosphorylation and dysregulations in zinc and lipid metabolism in liver tissue, which has been reported as responsible for postnatal variations of the phenotype.Nowadays, assisted reproductive technologies (ARTs) are considered valuable contributors to our past, but a future without their use is inconceivable. However, in recent years, several studies have evidenced a potential impact of ART on long-term development in mammal species. To date, the long-term follow-up data are still limited. So far, studies have mainly focused on in vitro fertilization or in vitro culture, with information from gametes/embryos cryopreservation field being practically missing. Herein, we report an approach to determine whether a vitrified embryo transfer procedure would have long-term consequences on the offspring. Using the rabbit as a model, we compared animals derived from vitrified-transferred embryos versus those naturally conceived, studying the growth performance, plus the weight throughout life, and the internal organs/tissues phenotype. The healthy status was assessed over the hematological and biochemical parameters in peripheral blood. Additionally, a comparative proteomic analysis was conducted in the liver tissue to investigate molecular cues related to vitrified embryo transfer in an adult tissue. After vitrified embryo transfer, birth weight was increased, and the growth performance was diminished in a sex-specific manner. In addition, vitrified-transferred animals showed significantly lower body, liver and heart weights in adulthood. Molecular analyses revealed that vitrified embryo transfer triggers reprogramming of the liver proteome. Functional analysis of the differentially expressed proteins showed changes in relation to oxidative phosphorylation and dysregulations in the zinc and lipid metabolism, which has been reported as possible causes of a disturbed growth pattern. Therefore, we conclude that vitrified embryo transfer is not a neutral procedure, and it incurs long-term effects in the offspring both at phenotypic and molecular levels. These results described a striking example of the developmental plasticity exhibited by the mammalian embryo.

Механизмы адипотропного действия цинка и их роль в патогенезе ожирения

Клинические и экспериментальные работы демонстрируют взаимосвязь между ожирением и нарушением метаболизма цинка, однако локальные эффекты цинка в жировой ткани изучены недостаточно. В связи с этим, целью обзора явился анализ данных о механизмах адипотропного действия цинка и их роли в патогенезе ожирения. Экспериментальные работы показали, как снижение уровня цинка в жировой ткани при ожирении, так и влияние цинка на дифференцировку и функционирование адипоцитов. Таким образом, цинк может рассматриваться в качестве одного из регуляторов адипогенеза, в связи с чем нарушение обмена цинка может сопровождаться дисфункцией жировой ткани. Модуляция активности транспортеров цинка обусловливает изменение уровня цинка в клетках, в то же время дальнейшие процессы реализации адипотропных функций цинка связаны с функционированием эффекторных молекул. Среди транспортеров цинка, функционирование которых тесно связано с регуляцией адипогенеза, выделяются ZIP14 и ZNT7, активно экспрессирующиеся в процессе созревания адипоцитов. Цинк-α2-гликопротеин является адипокином, действующим как аутокринный и паракринный регулятор метаболизма адипоцитов, а также как фактор активации липолиза. Влияние цинка на дифференцировку адипоцитов также может обусловливаться функционированием ряда белков цинковых пальцев, в первую очередь Zfp423 и Zfp521. Zfp423 является фактором дифференцировки адипоцитов, оказывающим стимулирующее влияние на экспрессию PPARγ, тогда как тормозное влияние Zfp521 достигается, в том числе, за счет подавления активности Zfp423. Несмотря на роль цинксодержащих металлопротеинов, значительная часть эффектов может быть обусловлена действием низкомолекулярных соединений цинка или непосредственно катионом Zn2+. Таким образом, коррекция обмена цинка в организме в целом и в жировой ткани в частности может рассматриваться в качестве одного из способов нормализации метаболизма жировой ткани при ожирении. Experimental and clinical studies have demonstrated an association between obesity and impaired zinc metabolism, although local effects of zinc in adipose tissue are insufficiently studied. The objective of this study was to review current data on adipotropic effects of zinc and its role in the pathogenesis of obesity. Experimental studies have shown both decreased content of zinc in the adipose tissue in obesity and effects of zinc on adipocyte differentiation and functioning. Therefore, zinc can be considered as a regulator of adipogenesis, and, thus, impaired zinc metabolism may be associated with adipose tissue dysfunction. Modulation of zinc transporters underlies alteration of intracellular zinc levels, whereas further effects of zinc are related with functioning of zinc-containing effector molecules. The zinc transporters known to play a significant role in regulation of adipogenesis include ZIP14 and ZNT7 that are actively expressed during adipocyte maturation. Zinc-α2-glycoprotein is an adipokine acting as an autocrine and paracrine regulator of adipocyte metabolism as well as a lipolytic factor. The effect of zinc on adipose tissue differentiation may be also mediated by zinc-finger proteins, primarily Zfp423 and Zfp521. Zfp423 is an adipocyte differentiation factor stimulating the PPARγ expression whereas the antiadipogenic effect of Zfp521 is mediated by Zfp423 down-regulation. Despite a clearly demonstrated effect of Zn-containing metalloproteins a significant part of the effects of zinc may be mediated by biological activity of low-molecular weight zinc compounds or directly by Zn2+ cation. Therefore, improvement of zinc metabolism in the body in general and the adipose tissue in particular can be considered as a strategy for improvement of adipose tissue metabolism in obesity.

Safety and efficacy of STABILFLOR® as a zootechnical feed additive for pigs for fattening.

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of STABILFLOR ® (zinc ethylenediaminetetraacetic acid (Zn‐EDTA) and copper diammonium EDTA (Cu‐EDTA) dried on chicory pulp and supplemented with zinc oxide and copper oxide), as a zootechnical additive for pigs. STABILFLOR ® is intended to be used in feed for pigs for fattening at a minimum and maximum levels of 500 and 1,000 mg/kg complete feed, respectively. The Panel could not conclude on the safety of STABILFLOR ® for pigs for fattening owing to the lack of adequate data. At the proposed used levels in feed the additive may exert antimicrobial activity in the gut microbiota. The use of the additive resulted neither in residues of Zn‐EDTA, Cu‐EDTA or EDTA nor on an increase in total zinc and copper deposition in edible tissues; Zn‐EDTA and Cu‐EDTA had not a genotoxic potential; the Panel concluded that STABILFLOR ® at 1,000 mg/kg complete feed for pigs does not pose any concern to the safety of consumers. The handling of STABILFLOR ® will lead to a copper exposure of the users that poses a risk by inhalation; the additive is not a skin irritant or a skin sensitiser but is a severe eye irritant. Regarding environmental safety, no concern was expected for the terrestrial compartment. A risk for groundwater was highlighted for Zn‐EDTA. Due to the absence of data, the risk for the aquatic compartment could not be assessed. Only one efficacy study showed positive effects of STABILFLOR ® in pigs for fattening at 1,000 mg/kg complete feed; a conclusion on the efficacy of STABILFLOR ® could not be drawn. The minimum use level of 500 mg STABILFLOR ®/kg complete feed was not tested.

Zinc-depletion associates with tissue eosinophilia and collagen depletion in chronic rhinosinusitis.

Zinc plays an important role in many biological processes. Reduced zinc levels have been found in chronic rhinosinusitis (CRS) patients, however, its role in the pathophysiology of this disease remains unknown. This study examined zinc levels in the serum, mucus and tissue from CRS patients in relation to collagen content and eosinophil infiltration. The effect of zinc depletion on inflammatory cytokine production and collagen synthesis was assessed in vitro. Zinc levels were determined in serum, mucus and tissue from controls, CRS with (CRSwNP) and without nasal polyps (CRSsNP) patients. Tissue zinc levels, collagen and inflammatory cell infiltration was examined using zinquin assays, immunofluorescence and histology on Tissue Micro Arrays. Cytokine expression and collagen synthesis was evaluated in zinc depleted primary human nasal epithelial cells (HNECs) and primary fibroblasts. CRSwNP patients showed reduced tissue zinc levels in correlation with a reduction in collagen content, and increased eosinophil numbers. Zinc depletion of HNECs and fibroblasts induced the production of pro-inflammatory cytokines and MUC5AC and reduced collagen secretion. These results suggest mucosal zinc depletion associates with tissue eosinophilia and collagen depletion in CRSwNP and induces pro-inflammatory cytokine expression and reduction of collagen synthesis in vitro.

Effect of aquaculture-agriculture sewage on the relation between iron and other trace elements content in Venus clam

In coastal systems, concentrations of trace metals in filter feeders such as shellfish may be affected by anthropogenic activities, including agriculture and aquaculture. Shellfish are a good source of iron, but can also be a potential source of toxic elements, such as cadmium and lead, when consumed by humans. The objective of this study was to determine the differences in iron, zinc, copper, manganese, nickel, lead, and cadmium levels in tissue of the clam Chione gnidia collected from a coastal lagoon influenced by agriculture (Lobos) or aquaculture (Tobari), using an atomic absorption spectrophotometer. The relationship of iron with all other trace elements in these organisms was explored using a generalized linear model (GLM). Iron, copper, manganese, and cadmium concentrations were significantly higher in shellfish collected from the coastal lagoon influenced by agriculture, while nickel was significantly higher in shellfish from the lagoon influenced by aquaculture. In these shellfish, cadmium and lead levels were the factors limiting the weekly intake of clam flesh. The GLM model explained 59% of the iron concentration in the Venus clam, suggesting that this element is directly related to zinc and manganese levels, but inversely related to cadmium content in shellfish.

Dynamics of heavy metal uptake and soil heavy metal stocks across a series of Masson pine plantations

To evaluate the roles of the plantations in cleaning soil heavy metals, the concentrations of copper (Cu), manganese (Mn), lead (Pb) and zinc (Zn) in both plant tissues and soils were therefore measured in the young (5a), half-mature (15a), near-mature (21a) and mature (27a) Masson pine (Pinus massoniana) plantations, and their stocks were further calculated. The concentrations of heavy metals varied with stand ages and tissues. The highest concentrations of Pb, Zn and Cu in pines were found in the half-mature plantation, while the highest value of Mn was found in the near-mature plantation. The concentrations and bioconcentration factors (BCFs) of Cu and Pb in pine tissues followed the order of root > need > branch > bark > trunk, and those of Mn and Zn followed the order of need > branch > bark > bark > root > trunk. Cu, Mn, Pb and Zn were stored mainly in the trunk, and the highest stocks of plants were found in the near-mature plantation. Although the concentrations and stocks of heavy metals in soils were not decreased with stand ages, the sustainable phytoextraction of Masson pine for heavy metals as affected by huge biomass and large planting area made Masson pine plantations play a positive role in cleaning soil heavy metals in non-point source pollution regions. Accordingly, it is highly recommended to log the near-mature Masson pine plantation to maximize the benefits of cleaning soil heavy metals and timber income.

The impact of humic acid additives on mineral metabolism of rabbits in the postnatal period of ontogenesis

Humic acids are characterized by chelating properties due to which they are able to influence the mineral metabolism in animals. Rabbits have species-specific characteristics of mineral metabolism, which distinguishes them from most species of mammals. For the experiment, 16 rabbits of 45-day-old of Hyplus breed were divided into the experimental and control group of 8 rabbits in each. The animals were 15 days in the preparatory period. The rabbits of the experimental group received humic acid additive individually with water in the amount of 5 mg/kg, the rabbits of the control group received pure water in the same amount. The ability of humic acid additive to increase the content of calcium, ionized calcium, iron, to correct the content of copper and zinc, and also to increase the activity of alkaline phosphatase in the blood serum of rabbits of the experimental group has been proved. We observed the early effect of the humic acid additive on increasing the content of iron and calcium ionized and a later effect on the activity of alkaline phosphatase and an increase in the content of copper in the blood serum. The influence of humic acid additive on the distribution of calcium, phosphorus, manganese, copper and zinc in bone tissue is determined. According to a histological study, there was a significant increase in the number of layers of osteons and osteoblasts in the bone tissue of the femur, an increase in the number of osteons and osteoblasts in the bone tissue of the sternum and an increase in the number of columns of chondrocytes and an increase in the number of chondrocytes in the column in the cartilaginous tissue of the sternum. The results of a histological study of bone tissue, together with an increase in structural macroelements in it and redistribution of osteotropic trace elements in the blood and bone tissue suggest the possibility of using a humic acid additive to intensify the growth and mineralization of bone tissue, which can improve the state of bone tissue of rabbits in the postnatal period ontogenesis.

The impact of humic acid additives on mineral metabolism of rabbits in the postnatal period of ontogenesis

Humic acids are characterized by chelating properties due to which they are able to influence the mineral metabolism in animals. Rabbits have species-specific characteristics of mineral metabolism, which distinguishes them from most species of mammals. For the experiment, 16 rabbits of 45-day-old of Hyplus breed were divided into the experimental and control group of 8 rabbits in each. The animals were 15 days in the preparatory period. The rabbits of the experimental group received humic acid additive individually with water in the amount of 5 mg/kg, the rabbits of the control group received pure water in the same amount. The ability of humic acid additive to increase the content of calcium, ionized calcium, iron, to correct the content of copper and zinc, and also to increase the activity of alkaline phosphatase in the blood serum of rabbits of the experimental group has been proved. We observed the early effect of the humic acid additive on increasing the content of iron and calcium ionized and a later effect on the activity of alkaline phosphatase and an increase in the content of copper in the blood serum. The influence of humic acid additive on the distribution of calcium, phosphorus, manganese, copper and zinc in bone tissue is determined. According to a histological study, there was a significant increase in the number of layers of osteons and osteoblasts in the bone tissue of the femur, an increase in the number of osteons and osteoblasts in the bone tissue of the sternum and an increase in the number of columns of chondrocytes and an increase in the number of chondrocytes in the column in the cartilaginous tissue of the sternum. The results of a histological study of bone tissue, together with an increase in structural macroelements in it and redistribution of osteotropic trace elements in the blood and bone tissue suggest the possibility of using a humic acid additive to intensify the growth and mineralization of bone tissue, which can improve the state of bone tissue of rabbits in the postnatal period ontogenesis.

The metabolic function of the metal transporter SLC39A14

Microelement is one of the nutritional elements of the human body. They participate in a wide range of physiological and biochemical functions of the human body, such as electron transport, oxygen delivery, enzyme activity, and cell growth and differentiation, etc. They also could be used as auxiliary components of biological macromolecules, or as the functional components of hormones and vitamins, which are of great significance to maintain life activities. Among them, essential trace elements, such as iron, zinc, and manganese, are not produced or synthesized in the body, but indispensable to maintain the whole-body physiological function. Essential trace elements are absorbed and transported into the blood circulation by a variety of metal transporters in the upper digest tract. Recently, with the identification and discovery of metal transporters and multifunctional study, we gain an in-depth understanding of metal transporters in metabolic organs and various metabolic diseases. Solute carrier 39 (SLC39), also known as zinc importer protein (ZIP) family, is a metal importer. According to the homology analysis of gene sequence, this family has 14 members, SLC39A1–SLC39A14 (ZIP1–ZIP14). Based on the protein structure, ZIP family could be divided into four subfamilies: I, II, Gufa, and LIV-1. SLC39A14 belongs to the LIV-1 subfamily of ZIP zinc transporters (LZT) family. It has 8 transmembrane domains (TM), histidine-rich domains and a conserved “HEXHEXGD” fragment. SLC39A14 is mainly expressed on the cellular membrane. Recent studies have demonstrated that it is involved in the absorption of metals like zinc, iron, and manganese in different metabolic tissues or organs. The function of SLC39A14 was investigated by generating global or tissue-specific knockout mice in different metabolic organs such as the liver, pancreas, adipose, and skeletal muscle. Most of these studies indicate that Slc39a14 -deletion may perturb tissue metabolic functions, such as insulin synthesis and secretion, disrupted insulin sensitivity or tissue metal absorption. More specifically, for the Slc39a14 global knockout mice ( Slc39a14-KO ), the insulin sensitivity and adipocyte differentiation are impaired in adipose tissue. Slc39a14-KO also disrupts gluconeogenesis in hepatic tissue induced by low tissue zinc content. Meanwhile, hepatocyte-specific knockout of Slc39a14 shows that SLC39A14 may be involved in hepatic manganese transportation and non-transferrin-bound iron (NTBI). In the mouse β cell line (Min6), SLC39A14 is involved in the endocrinal function of the pancreas, especially the insulin synthesis and secretion function in β cell. Furthermore, SLC39A14 function in skeletal muscle and myoblast suggests that SLC39A14 may regulate tissue zinc homeostasis in skeletal muscle of tumor metastasis animal model. In C2C12 myoblasts, SLC39A14 participates in myogenic differentiation and myotube development. In addition, the expression of SLC39A14 is not only regulated by the concentration of trace elements in blood circulation and intake level of elements from diets but also regulated by inflammatory factors such as LPS and IL-6. In this review, the metabolic function of metal transporters SLC39A14 in different tissues and organs is summarized.

Heavy Metals Analysis of the Limpet Cellana Karachiensis (Winckworth 1930) from Two Rocky Shores of the Karachi Coasts of Pakistan

In current years, observing the concentration of heavy metals in marine biota has received much awareness as the public are more aware about the healthy environment and food. Intensity of these metals in a huge range of finfish and shellfish would give baseline information for some of the toxic metals. In the present investigation an attempt has been made to study the presence and concentration of some heavy metals in the true limpet Cellana karachiensis a gastropod mollusk which is abundantly found at the intertidal to high tidal zones of different rocky shores of Sind and Baluchistan coasts of Pakistan. In the present study two distinct anthropogenic dynamic rocky shores i.e., Clifton and Mubarak village of Karachi coast was selected to analyse the heavy metals in soft tissues of C. karachiensis which accept as a good bio-indicator mollusk to observe heavy metal pollution awareness. The concentration of zinc (Zn), chrome (Cr), copper (Cu), lead (Pb) and cadmium (Cd) in the soft tissue of the limpet C. karachiensis from two rocky shores in the Karachi coast has been measured by Atomic Absorption Spectrometer (A Analyst 700) for monitoring metal contamination of samples. Accumulation of Zn was found highest followed by Cr, Cu, Pb and Cd in the months of July and August 2019 in Clifton shores. While at the same period the highest concentration was Zn followed by Cu, Cd, Cr and Pb at Mubarak village shore. It has been observed that, C. karachiensis at Clifton shore accumulated more than heavy metals that found at Mubarak village shore. The pattern of accumulation of Heavy metals at both sites of limpets did not exhibit much difference. ANOVA single factor and student t test was done for the statistical analysis of metal contents in soft tissues of C. karachiensis of both shores at (p<0.01) and observed statistically significant differences in the amounts of the Cu, Cd and Zn elements among the limpets of both rocky shores. Same as the significant result at p<0.01 and p<0.05 was observed in between the length size of limpets at Clifton and Mubarak Village rocky shores. Correlation studies carried out for the metal concentrations in limpet and shell length of the animal which did not show significant results except Cu at Mubarak village shore. The results were compared with previous studies and discussed.

Effect of zinc nanoparticles on embryo and chicken growth, and the content of zinc in tissues and faeces

The hypothesis was that owing to their high bioavailability, zinc oxide nanoparticles (NanoZnO) can effectively replace (Zn) salts and reduce Zn excretion with faeces. The objective of this study was to investigate the effects of NanoZnO on the development of chicken embryos, the growth of broiler chickens, and Zn excretion with faeces. At day 1 of incubation, 120 eggs were randomly divided between a control group (not injected) and groups injected with a hydrocolloid of NanoZnO in increasing concentrations (50, 100, 500 mg/L). At day 19 of incubation, no differences were observed in the bodyweight, but 100 and 500 mg/L affected liver and heart weights, indicating that high levels of NanoZnO may induce differential organ development. In the subsequent experiment, 308 chickens were randomly divided into six groups. The control diet was supplemented with 55 mg Zn/kg (standard level), the 0 group received no Zn supplement, and groups fed NanoZnO received 25%, 50%, 75%, and 100% of the standard level. The 100% replacement of ZnO with NanoZnO increased the chickens’ bodyweight compared with the standard level of ZnO, but to the same level as the diet without ZnO supplementation. Furthermore, NanoZnO did not reduce the content of Zn in faeces, which was only significantly lower in the group without ZnO supplementation in comparison with other groups. The results indicate that the replacement of ZnO with NanoZnO had no negative effects on chicken growth. Compared with ZnO, NanoZnO did not reduce Zn excretion with faeces.
 Keywords: broiler, development, excretion, mineral, nanonutrition

Evaluation of the content and bioaccessibility of selected metals from barley grass

The evaluation of the content of zinc and copper in plant tissues of barley grass growing on enriched in zinc/copper solutions (sulphate, glycine complex, rutin complex) were studied by inductively coupled plasma mass spectrometry. The highest concentrations of Zn were found in the roots and leaves, growing on solutions enriched in the rutin-zinc(II) and sulphate solutions. The highest concentrations of Cu were found in the leaves, growing on solutions enriched in the glycine-copper(II) complex solutions. The research showed that the barley accumulates the zinc/copper from the nutrient solution, therefore, in the next step of the investigation the evaluation of bioaccessibility was carried out. The bioaccessibility of copper and zinc were evaluated from the various enriched cultivation solutions by the inductively coupled mass spectrometry coupled with size exclusion chromatography. Plants growing on solutions enriched in the zinc/copper complexes with amino acids (glycine) and flavonoids (rutin) accumulated excessive amounts of these elements in tissues. Additionally, the bioaccessibility is significantly higher than from the plant’s tissues growing on zinc/copper salts solutions.

Essential trace elements in placental tissue and risk for fetal neural tube defects

This study examined the associations between concentrations of cobalt (Co), iron (Fe), manganese (Mn), molybdenum (Mo), selenium (Se), and zinc (Zn) in placental tissue and risks for NTDs with a case-control design consisting of 408 fetuses or newborns with neural tube defects (NTDs) and 593 non-malformed fetuses or newborns. The concentrations of Zn and Fe were determined by inductively coupled plasma-emission spectrometer and the other four elements by inductively coupled plasma-mass spectrometer. Element concentrations were presented in ng/g or µg/g dry weight of placental tissue. The associations between the levels of each of the six ETEs and risk for NTDs were evaluated using multivariable logistic regression, and the associations between overall levels of all six ETEs and risk for NTDs were examined using Bayesian kernel machine regression (BKMR). Concentrations above the median concentration of all participants for an individual element were associated with increased risk for NTDs: Mn, 3.17-fold (95% CI 2.35–4.28); Mo, 3.73-fold (95% CI 2.74–5.07); Se, 3.28-fold (95% CI 2.44–4.42); and Zn, 2.85-fold (95% CI 2.13–3.83), and a decreased risk for Co [OR, 0.18 (95% CI 0.14–0.25)]. The risk for NTDs increased with the increase in the concentrations of Mn, Mo, Se, and Zn, but decreased for Co, in the second, third, and fourth quartiles, respectively, compared to their lowest quartile (all Pstrend < 0.01). In BKMR model, the risk for NTDs increased constantly when the overall exposure levels were higher than the median of the six ETEs as a co-exposure mixture, and the associations between Co, Mn, Se, and Zn and NTD risk remained when the remaining five elements were taken into consideration simultaneously. Taken together, when evaluated individually, higher levels of Mn, Se, and Zn in placental tissue are associated with increased risk for NTDs, while higher levels of Co are associated with decreased risk for NTDs; when examined collectively, the risk of NTDs increases continuously when exposure levels are higher than the median of the six ETE mixture.

Assessment of Hair Zinc in the School Children in Kayseri, Turkey.

Zinc is an essential micronutrient for the organism and is critical for the functional and structural integrity of cells. Determination of the amount of trace element concentrations in tissues such as hair samples have been used for the evaluation of the metabolic status especially in children. Unlike serum zinc, concentrations of zinc in hair are more stable and indicative of variations over time. The purpose of this study is to assess the zinc status of healthy school-age children in Kayseri (Turkey) by measuring the zinc level in hair samples and its association with BMI and the frequency of intake of zinc-rich foods. A total of 527 healthy children, including preadolescent (n = 360) aged 6-10years and adolescent (n = 167) aged 11-15years were included in this study. Hair samples were analyzed for zinc content by the inductively coupled plasma-mass spectrophotometry. Analysis of 527 healthy children showed that the mean hair zinc level was 186 ± 77μg/g. Mean hair zinc level was lower in preadolescent age group than adolescents. There was no significant relationship between the monthly income of the family and the zinc-rich food intake and the zinc level of the hair. Our study shows that samples for analysis of zinc can be obtained with a noninvasive method for determining cases of deficiency during periods of rapid growth. However, further studies are needed to determine the normal tissue zinc level in healthy children, especially in our country and including different geographical regions.

Waterborne Exposure of Adult Sand Dollar, Scaphechinus Mirabilis (Agassiz, 1864), to Zinc Ions and Zinc Oxide Nanoparticles Affects Early Development of its Offspring

Early development of the sand dollar, Scaphechinus mirabilis, and damage to DNA molecules in spermatozoa and larval cells were studied after a waterborne exposure of adult individuals to zinc ions (Zn2+) and zinc oxide nanoparticles (ZnO NP). It was found that the proportion of retarded and abnormal larvae increases if the parental individuals have been kept in aqueous solutions containing ionic and nanoform of zinc at concentrations of 100 and 200 μg/L. The percentage of DNA in comet tail and GDI was higher after the exposure to ZnO NP, compared with the Zn2+ exposure, at a concentration of 200 μg/L. Accumulation of zinc in soft tissues of S. mirabilis was also studied. The zinc concentrations in the soft tissues of both experimental groups of sand dollars proved to be higher than that in control groups. The results of the study have shown that the ionic form of zinc exhibits a lower bioavailability compared with ZnO NP and supported the higher toxic effect of the high concentrations ZnO NP.

Trace elements and oxidative stress in the Ark shell Arca noae from a Mediterranean coastal lagoon (Bizerte lagoon, Tunisia): are there health risks associated with their consumption?

The current study examined the concentrations of ten trace elements (TE) (nickel, chromium, cadmium, iron, zinc, manganese, aluminum, copper, selenium and lead) in the edible tissue of the Ark shell Arca noae (L. 1758) from a Mediterranean coastal lagoon, the Bizerte lagoon during 2013-2014. The analysis of several redox status biomarkers, metallothioneins (MTs), malondialdehyde (MDA), glutathione peroxidase (GPx), reduced glutathione (GSH) and acetylcholinesterase (AChE), was monitored as a response to TE bioaccumulation and environmental parameters variability. Significant differences (p < 0.05) were observed between mean seasonal TE concentrations in A. noae soft tissue. The highest TE concentrations in A. noae soft tissues were recorded during summer, which coincided with the increase of body dry weight (BDW) and the gonad index (GI). During this season, biomarker responses were enhanced, revealing significant increases of MTs, MDA and GSH levels as well as GPx activity in A. noae tissues, while a decrease of AChE activity was observed. The levels of TE analyzed in A. noae and several parameters used to assess the potential human risk (estimated weekly intake, target hazard quotient and target hazard risk) were lower than the permissible limits for safe seafood consumption. Consequently, this shellfish can be considered safe for human consumption. This preliminary study presents prospects for the valorization of this seafood product in Tunisia's food sector. It also gives basal information for future environmental assessment studies in which A. noae could be used as early warning tools in the field of biomonitoring programs and confirms the usefulness of biomarkers to monitor the health status of aquatic organisms.

Assessment of ZnO-NPs toxicity in maize: An integrative microRNAomic approach

Rapid expansion of nanotechnology and indiscriminate discharge of metal oxide nanoparticles (NPs) into the environment pose a serious hazard to the ecological receptors including plants. To better understand the role of miRNAs in ZnO-NPs stress adaptation, two small RNA libraries were prepared from control and ZnO-NPs (800 ppm, <50 nm particle size) stressed maize leaves. Meager performance of ZnO-NPs treated seedlings was associated with elevated tissue zinc accumulation, enhanced ROS generation, loss of root cell viability, increased foliar MDA content, decrease in chlorophyll and carotenoids contents. Deep sequencing identified 3 (2 known and 1 novel) up- and 77 (73 known and 4 novel) down-regulated miRNAs from ZnO-NPs challenged leaves. GO analysis reveals that potential targets of ZnO-NPs responsive miRNAs regulate diverse biological processes viz. plant growth and development (miR159f-3p, zma_18), ROS homeostasis (miR156b, miR166l), heavy metal transport and detoxification (miR444a, miR167c-3p), photosynthesis (miR171b) etc. Up-regulation of SCARECROW 6 in ZnO-NPs treated leaves might be responsible for suppression of chlorophyll biosynthesis leading to yellowing of leaves. miR156b.1 mediated up-regulation of CALLOSE SYNTHASE also does not give much protection against ZnO-NPs treatment. Taken together, the findings shed light on the miRNA-guided stress regulatory networks involved in plant adaptive responses to ZnO-NPs stress.