Zinc requirements and the risks and benefits of zinc supplementation

Metal exposure in the Greenlandic ACCEPT cohort: follow-up and comparison with other Arctic populations

Humans are exposed to metals through diet and lifestyle e.g. smoking. Some metals are essential for physiologically body functions, while others are non-essential and can be toxic to humans. This study follows up on metal concentrations in the Greenlandic ACCEPT birth-cohort (mothers and fathers) and compares with other Arctic populations. The data from 2019 to 2020 include blood metal concentrations, lifestyle and food frequency questionnaires from 101 mothers and 76 fathers, 24-55 years, living in Nuuk, Sisimiut, and Ilulissat. A high percentage (25-45%) exceeded international guidance values for Hg. For the mothers, the metal concentrations changed significantly from inclusion at pregnancy to this follow-up 3-5 years after birth; some increased and others decreased. Most metals differed significantly between mothers and fathers, while few also differed between residential towns. Several metals correlated significantly with marine food intake and socio-economic factors, but the direction of the correlations varied. Traditional marine food intake was associated positively with Se, As and Hg. To the best of our knowledge, this study provides the most recent data on metal exposure of both men and women in Greenland, elucidating metal exposure sources among Arctic populations, and documents the need for continuing biomonitoring to follow the exceeding of guidance values for Hg. [Figure: see text].

Efficacy of zinc nanoparticle supplementation on ruminal environment in lambs

BACKGROUND

Zinc nanoparticles (NPs) are characterized by high bioavailability, small size, and high absorbability. The purpose of this experiment was to determine the effect of Zn-NP feed supplementation on ruminal fermentation, microbiota, and histopathology in lambs. In vitro (24 h), short-term (STE, 28 d), and long-term (LTE, 70 d) experiments were performed. The lambs in STE were fed a basal diet (BD) composed of 350 g/d ground barley and 700 g/d meadow hay (Control), BD enriched with ZnO-NPs (80 mg Zn/kg of diet, ZnO-NPs), and BD enriched with Zn phosphate-based NPs (80 mg Zn/kg of diet, ZnP-NP). The in vitro gas production technique was used in incubated rumen fluid from STE. The lambs in LTE were fed BD (Control), BD enriched with ZnO-NPs (40 mg Zn/kg of diet, ZnO-NP40), BD enriched with ZnO-NPs (80 mg Zn/kg of diet, ZnO-NP80) and BD enriched with ZnO (80 mg Zn/kg of diet, ZnO-80).

RESULTS

After 24 h of incubation, dry matter digestibility was higher for ZnO-NP and ZnP-NP substrates than the control in an in vitro experiment (P < 0.001). The total bacterial population in the STE was lower (P < 0.001) in the ZnP-NP group than in the control and ZnO-NP groups, but the protozoan populations were not significantly different. The ammonia-N concentration in LTE was lowest in the ZnO-NP80 group (P = 0.002), but the activities of carboxymethyl cellulase (P < 0.001) and xylanase (P = 0.002) were higher in the ZnO-NP40, ZnO-NP80, and ZnO-80 groups than in the control group. Morphological observation after STE and LTE revealed histological changes (e.g. inflammation of the epithelium or edema of the connective tissue) in the rumen of lambs.

CONCLUSION

Zn-NP supplementation up to 70 d improved feed-use efficiency and influenced ammonia-N concentration and activities of hydrolases in the rumen. The active ruminal fermentation affected the health of the ruminal papillae and epithelium in the lambs, regardless of the application's form, dose, or duration. However, by affecting rumen microbial fermentation, Zn-NPs could alter fermentation patterns, thereby increasing the capacity of host rumen epithelial cells to transport short-chain fatty acids.

Investigating the Impact of Nutrition and Oxidative Stress on Attention Deficit Hyperactivity Disorder

Background/Objectives: Attention deficit hyperactivity disorder (ADHD) is the most common childhood-onset neurodevelopmental disorder, characterized by difficulty maintaining attention, impulsivity, and hyperactivity. While the cause of this disorder is still unclear, recent studies have stated that heredity is important in the development of ADHD. This is linked to a few comorbidities, including depression, criminal behavior, and anxiety. Although genetic factors influence ADHD symptoms, there are also non-genetic factors, one of which is oxidative stress (OS), which plays a role in the pathogenesis and symptoms of ADHD. This review aims to explore the role of OS in ADHD and its connection to antioxidant enzyme levels, as well as the gut-brain axis (GBA), focusing on diet and its influence on ADHD symptoms, particularly in adults with comorbid conditions. Methods: The literature search included the main available databases (e.g., Science Direct, PubMed, and Google Scholar). Articles in the English language were taken into consideration and our screening was conducted based on several words such as "ADHD", "oxidative stress", "diet", "gut-brain axis", and "gut microbiota." The review focused on studies examining the link between oxidative stress and ADHD, the role of the gut-brain axis, and the potential impact of dietary interventions. Results: Oxidative stress plays a critical role in the development and manifestation of ADHD symptoms. Studies have shown that individuals with ADHD exhibit reduced levels of key antioxidant enzymes, including glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD), as well as a diminished total antioxidant status (TOS) compared to healthy controls. Additionally, there is evidence of a close bidirectional interaction between the nervous system and gut microbiota, mediated by the gut-brain axis. This relationship suggests that dietary interventions targeting gut health may influence ADHD symptoms and related comorbidities. Conclusions: Oxidative stress and the gut-brain axis are key factors in the pathogenesis of ADHD, particularly in adults with comorbid conditions. A better understanding of these mechanisms could lead to more targeted treatments, including dietary interventions, to mitigate ADHD symptoms. Further research is required to explore the therapeutic potential of modulating oxidative stress and gut microbiota in the management of ADHD.

A Critical Review of Biodegradable Zinc Alloys toward Clinical Applications

Biodegradable zinc (Zn) alloys stand out as promising contenders for biomedical applications due to their favorable mechanical properties and appropriate degradation rates, offering the potential to mitigate the risks and expenses associated with secondary surgeries. While current research predominantly centers on the in vitro examination of Zn alloys, notable disparities often emerge between in vivo and in vitro findings. Consequently, conducting in vivo investigations on Zn alloys holds paramount significance in advancing their clinical application. Different element compositions and processing methods decide the mechanical properties and biological performance of Zn alloys, thus affecting their suitability for specific medical applications. This paper presents a comprehensive overview of recent strides in the development of biodegradable Zn alloys, with a focus on key aspects such as mechanical properties, toxicity, animal experiments, biological properties, and molecular mechanisms. By summarizing these advancements, the paper aims to broaden the scope of research directions and enhance the understanding of the clinical applications of biodegradable Zn alloys.

The Role of Selected Elements in Oxidative Stress Protection: Key to Healthy Fertility and Reproduction

Oxidative stress and its relationship to fertility and reproduction is a topic of interest in medicine, especially in the context of the effects of trace elements and micronutrients. Oxidative stress occurs when there is an excess of free radicals in the body, which can lead to cell and tissue damage. Free radicals are reactive oxygen species (ROS) that can be formed as a result of normal metabolic processes, as well as under the influence of external factors such as environmental pollution, UV radiation, and diet. Oxidative stress has a significant impact on fertility. In men, it can lead to DNA damage in sperm, which can result in reduced semen quality, reduced sperm motility and increased numbers of defective sperm, and free radical damage to sperm cell membranes causing a reduction in the number of available sperm. In women, oxidative stress can affect the quality of female reproductive cells, which can lead to problems with their maturation and with embryo implantation in the uterus and can also affect ovarian function and disrupt hormonal regulation of the menstrual cycle. A proper balance of trace elements and micronutrients is key to protecting against oxidative stress and maintaining reproductive health. Supplementation with appropriate elements such as zinc, selenium, copper, manganese, chromium, and iron can help reduce oxidative stress and improve fertility. This work discusses the effects of selected elements on oxidative stress parameters specifically in terms of fertility and reproduction.

Maternal immune activation accelerates pup reflex development and alters immune proteins in pup stomach contents and brain

Prenatal infection increases the risk for neurodevelopmental disorders including autism spectrum disorder and schizophrenia. To better understand this link, a number of maternal immune activation (MIA) rodent models have been studied. However, the majority of these studies focus on adult behavioural outcomes that mirror adult symptoms related to neurodevelopmental disorders. There is little research reporting the effects of MIA on early postnatal development and even fewer using outbred mouse strains. Here, we use a modified version of the Fox scale to assess the effects of two MIA models, a bacterial model (LPS) and a viral model (PolyIC), on overall mouse pup sensorimotor development in CD-1 mice. Surprisingly, both bacterial and viral MIA models resulted in early reflex development when compared with control pups. To better characterize potential factors related to these changes, we examined indicators of sickness/inflammation in the immune-activated dams and in their pups. Sickness behaviour in the dams resulting from immune activation was assessed using a telemetry implant that allowed for continuous recording of temperature and activity in dams exposed to bacterial or viral immune activation. Although MIA dams showed reduced activity on the day immediately following MIA compared to controls, there was no evidence of fever. All dams showed elevated cytokines/chemokines associated with parturition, but this resolved by day 10 post-parturition and was unaffected by previous immune activation. Although circulating cytokines/chemokines in the dams were similar across MIA treatments, there were differences in the amount of interleukin-12p70 and interleukin-13 present in milk taken from milk bands in MIA pups, and interleukin-4 was overall decreased in LPS pup brain. These findings demonstrate that bacterial and viral models of MIA can result in similar precocious development in mice but differing long-term effects on inflammatory markers in both the milk provided to the pups and in their brains.

Dietary zinc supplements: beneficial health effects and application in food, medicine and animals

Zinc, a crucial trace element is vital for the growth and development of humans. It is frequently described as 'the flower of life' and 'the source of intelligence'. Zinc supplements play a pivotal role in addressing zinc deficiency by serving as a vital source of this essential micronutrients, effectively replenishing depleted zinc levels in the body. In this paper, we first described the biological behavior of zinc in the human body and briefly described the physiological phenomena associated with zinc levels. The benefits and drawbacks of various zinc supplement forms are then discussed, with emphasis on the most recent zinc supplement formulations. Finally, the application of zinc supplements in food, medicine, and animal husbandry is further summarized. © 2024 Society of Chemical Industry.

Schiff baseAlkyne precursor for1,2,3-Triazole functionalized organosiliconas a PotentialSensor for Zn(II)andAntioxidantActivity

Schiff base linked1,2,3-triazole silane5has been synthesized through the Schiff base terminated alkyne with azido via click chemistry,the compound4 structure elucidated through X-ray crystallography, and the compound5 is well characterized through different techniques such asFT-IR, 1H and 13C NMR and Mass spectrometry. UV-visible sensing studies of synthesized compounds4 and5 have been performed, and both are efficient in detectingZn(II) ion, but compound 5 has imparted a higher mode of attraction to Zn(II) with limit of detection (LOD) value (1.4 x 10-6M) wherethe compound 4 is calculated to be (1.25 x 10-5M). By Job's method, the stoichiometric ratio of compound5 and Zn(II) iscalculated to bea 1:1 ratio. The complex of compound 5 with Zn(II) was prepared. A radical and oxidative species are responsible for the deteriorating of stabilized molecules. The synthesized compound 5hasantioxidant propertiesthat can potentially scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. Further to verify the mode of binding interaction between compound 5andZn(II), computational Density functional theory (DFT) study was evaluated.

An Overexpression of SLC30A6 Gene Contributes to Cardiomyocyte Dysfunction via Affecting Mitochondria and Inducing Activations in K-Acetylation and Epigenetic Proteins

Intracellular free Zn2+ ([Zn2+]i) is less than 1-nM in cardiomyocytes and its regulation is performed with Zn2+-transporters. However, the roles of Zn2+-transporters in cardiomyocytes are not defined exactly yet. Here, we aimed to examine the role of an overexpression and subcellular localization of a ZnT6 in insulin-resistance mimic H9c2 cardiomyoblasts (IR-cells; 50-μM palmitic acid for 24-h incubation). We used both IR-cells and ZnT6-overexpressed (ZnT6OE) cells in comparison to those of H9c2 cells (CON-cells). The IR-cells have higher ZnT6-protein levels than CON-cells while this level was similar to those of ZnT6OE-cells. The [Zn2+]i in IR-cells was increased significantly and mitochondrial localization of ZnT6 was demonstrated in these cells by using confocal microscopy visualization. Furthermore, electron microscopy analysis demonstrated abnormal morphological appearance in both IR-cells and ZnT6OE-cells characterized by irregular mitochondrion cristae and condensed and dilated cisterna in the sarcoplasmic reticulum. Mitochondria were similarly depolarized in both IR-cells and ZnT6OE-cells. The protein expression level of a mitofusin protein MFN2 in the IR-cells was decreased, significantly, whereas, it was found significantly upregulated in both ZnT6-OE-cells and IR-incubated ZnT6OE-cells, which demonstrates the role of ZnT6-overexpression but not IR. Additionally, the total protein level of a mitochondrial fission protein, dynamin-related protein 1, DRP1 was found to be increased over 1.5-fold in IR-cells while this increase was found to be higher in the ZnT6OE-cells than those of IR-cells, demonstrating an additional effect on IR-increase. ZnT6-overexpression induced also significant increases in K-acetylation, trimethylation of histone H3 lysine27, and mono-methylation of histone H3 lysine36, in a similar manner to those of IR-cells. Overall, our data point out an important contribution of ZnT6-overexpression to IR-induced cellular changes, such as alteration in mitochondria function and activation of epigenetic modifications.

Zinc(II) coordination compound with N'-(pyridin-2-ylmethylene)nicotinohydrazide: Synthesis, crystal structure, computational and cytotoxicity studies

In this work, we report on the synthesis of a novel zinc(II) coordination compound [ZnL2] (1), which was readily obtained from the reaction of Zn(OAc)·2H2O and N'-(pyridin-2-ylmethylene)nicotinohydrazide (HL) in methanol. Recrystallization of 1 from dimethylformamide under ambient conditions allowed to produce yellow block-like crystals of 1·H2O. Complex 1·H2O was characterized by FT-IR and 1H NMR spectroscopy, while its optical properties were studied by UV-vis and spectrofluorimetry in methanol. The crystal structure of the title complex was revealed by single crystal X-ray diffraction and further explored in detail by the Hirshfeld surface analysis. Theoretical investigations based on the DFT calculations have also been applied to show the electronic properties of complex 1. The antitumor activities of the parent ligand HL and complex 1 were studied using Dalton's lymphoma malignant cancer model. Both compounds were found to induce concentration-dependent cytotoxicity and apoptotic cell death, leading to a decrease in cell viability, body weight, and tumor volume in mice with the superior activity of complex 1 over HL. Mice treated with complex 1 demonstrated an increase in life span with a survival period of 23 days. Finally, using a molecular docking approach, we have probed complex 1 to inhibit the recombinant mouse tumor-necrosis factor alpha (mTNF).

Effects of dietary zinc on the gut microbiome and resistome of the gestating cow and neonatal calf

Zinc is an essential trace element required in the diet of all species. While the effects of zinc have been studied in growing calves, little is known about the effect of zinc on the microbiota of the gestating cow or her neonatal calf. Understanding factors that shape the gut health of neonatal animals and evaluating the effect of dietary supplements in adult gestating animals is important in promoting animal health and informing feeding practices. The aims of this study were to determine the effect of dietary zinc on the microbiota and resistome of the gestating cow and calf. Gestating cows received standard (40 ppm) or high (205 ppm) dietary zinc levels from dry off to calving. Fecal samples were collected from cows upon enrollment and at calving and from neonatal calves. Fecal samples underwent 16S rRNA sequencing and a subset also underwent shotgun metagenomic sequencing. The effect of zinc supplementation on the diversity and composition of the cow and calf microbiome and resistome was assessed. Alpha and beta diversity and composition of the microbiota were significantly altered over time but not by treatment in the cows, with alpha diversity decreasing and 14 genera found at significantly higher relative abundances at calving compared to enrollment. Levels of 27 antimicrobial resistance genes significantly increased over time. Only a small number of taxa were differentially expressed at calving in treatment and control groups, including Faecalibacterium, Bacteroides, Turicibacter, and Bifidobacterium pseudolongum. No effect of the dam's treatment group was observed on the diversity or composition of the neonatal calf microbiota. The calf resistome, which was relatively rich and diverse compared to the cow, was also unaffected by the dam's treatment group. The impact of high levels of dietary zinc thus appeared to be minimal, with no observed changes in alpha or beta diversity, and few changes in the relative abundance of a small number of taxa and antimicrobial resistance genes.

The 4T and 7T introgressions from Amblyopyrum muticum and the 5Au introgression from Triticum urartu increases grain zinc and iron concentrations in Malawian wheat backgrounds

Micronutrient deficiencies (MNDs) particularly zinc (Zn) and iron (Fe) remain widespread in sub-Saharan Africa (SSA) due to low dietary intake. Wheat is an important source of energy globally, although cultivated wheat is inherently low in grain micronutrient concentrations. Malawian wheat/Am. muticum and Malawian wheat/T. urartu BC1F3 introgression lines, developed by crossing three Malawian wheat varieties (Kenya nyati, Nduna and Kadzibonga) with DH-348 (wheat/Am. muticum) and DH-254 (wheat/T. urartu), were phenotyped for grain Zn and Fe, and associated agronomic traits in Zn-deficient soils, in Malawi. 98% (47) of the BC1F3 introgression lines showed higher Zn above the checks Paragon, Chinese Spring, Kadzibonga, Kenya Nyati and Nduna. 23% (11) of the introgression lines showed a combination of high yields and an increase in grain Zn by 16-30 mg kg -1 above Nduna and Kadzibonga, and 11-25 mg kg -1 above Kenya nyati, Paragon and Chinese Spring. Among the 23%, 64% (7) also showed 8-12 mg kg -1 improvement in grain Fe compared to Nduna and Kenya nyati. Grain Zn concentrations showed a significant positive correlation with grain Fe, whilst grain Zn and Fe negatively and significantly correlated with TKW and grain yield. This work will contribute to the efforts of increasing mineral nutrient density in wheat, specifically targeting countries in the SSA.

Zinc as a Possible Critical Element to Prevent Harmful Effects of COVID-19 on Testicular Function: a Narrative Review

Research into innovative non-pharmacological therapeutic routes via the utilization of natural elements like zinc (Zn) has been motivated by the discovery of new severe acute respiratory syndrome-related coronavirus 2 (SARS-COV2) variants and the ineffectiveness of certain vaccination treatments during COVID-19 pandemic. In addition, research on SARS-COV-2's viral cellular entry and infection mechanism has shown that it may seriously harm reproductive system cells and impair testicular function in young men and adolescents, which may lead to male infertility over time. In this context, we conducted a narrative review to give an overview of the data pertaining to Zn's critical role in testicular tissue, the therapeutic use of such micronutrients to enhance male fertility, as well as in the potential mitigation of COVID-19, with the ultimate goal of elucidating the hypothesis of the potential use of Zn supplements to prevent the possible harmful effects of SARS-COV2 infection on testis physiological function, and subsequently, on male fertility.

Association between dietary zinc intake and epilepsy: findings from NHANES 2013-2018 and a Mendelian randomization study

Background

The association between dietary zinc intake and epilepsy remains unclear. This study aimed to investigate the relationship between zinc intake from the diet and epilepsy, employing Mendelian randomization (MR) to explore potential causal links between zinc and epilepsy.

Methods

The cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) conducted between 2013 and 2018. Among the 4,434 participants included, 1.5% (67/4,434) reported having epilepsy. Restricted cubic spline models and logistic regression models were employed to examine the relationships between dietary zinc intakes and epilepsy. Subsequently, a 2-sample Mendelian randomization (MR) analysis was conducted using the inverse variance weighted (IVW) approach as the primary analysis.

Results

In the restricted cubic spline (RCS) analysis, the relationship between dietary zinc consumption and epilepsy displayed an L-shaped curve (nonlinear, p = 0.049). After multivariate adjustments, the adjusted odds ratios for epilepsy in T2 (5.0-11.0 mg/day) and T3 (≥11.0 mg/day) were 0.49 (95% confidence interval [CI]: 0.26-0.92, p = 0.026) and 0.60 (95% CI: 0.31-1.17, p = 0.132), respectively, compared to the lowest dietary zinc consumption tertile (T1, ≤5.0 mg/day). The IVW method indicated that genetically predicted zinc intake per standard-deviation increase was inversely associated with three types of epilepsy, including all types of epilepsy (OR = 1.06, 95% CI: 1.02-1.11, p = 0.008), generalized epilepsy (OR = 1.13, 95% CI: 1.01-1.25, p = 0.030), and focal epilepsy (documented hippocampal sclerosis) (OR = 1.01, 95% CI: 1.00-1.02, p = 0.025).

Conclusion

Our findings suggest that a daily zinc intake ranging from 5.0 to 11.0 mg is associated with the lowest risk of epilepsy. Furthermore, Mendelian randomization (MR) studies provide additional support for the existence of a causal relationship between zinc and epilepsy.

The Hidden Hunger among Nepalese Non-Pregnant Women Aged 15-49 Years: The Role of Individual, Household, and Community-Level Factors

Micronutrient deficiencies remain a public health burden among non-pregnant women in developing countries, including Nepal. Hence, this study examined micronutrient deficiencies among non-pregnant Nepalese women aged 15-49 using the 2016 Nepal National Micronutrient Status Survey (NNMSS). Data for 2143 non-pregnant women was extracted from the 2016 NNMSS. The study analysed the levels of ferritin, soluble transferrin receptor (sTfR), red blood cell (RBC) folate, and zinc of the participants. Multivariable logistic analysis was carried out to assess factors associated with micronutrient deficiencies. The prevalence of ferritin, sTfR, folate, and zinc was observed to be 19%, 13%, 16%, and 21%, respectively. Non-pregnant women from the Janajati region were significantly less prone to high levels of ferritin [adjusted odds ratio (AOR): 0.45; 95% confidence interval (CI): 0.25, 0.80], and those who had body mass index (BMI) of 25 kg/m2 or higher had significantly elevated ferritin levels [AOR: 2.69; 95% CI: 1.01, 7.17]. Non-pregnant women aged 35-49 years were significantly less predisposed to folate deficiency [AOR: 0.58; 95% CI: 0.40, 0.83], and the odds of zinc deficiency were significantly lower among non-pregnant women from wealthier households [AOR: 0.48; 95% CI: 0.31, 0.76]. This study provides further insight into screening high-risk subgroups and instituting public health interventions to address the prevailing micronutrient deficiencies among non-pregnant Nepalese women.

Nutrient Composition of Four Dietary Patterns in Italy: Results from an Online Survey (the INVITA Study)

Though Italy is a native land of Mediterranean diet, its adherence in the Italian population is low, witnessed by the high rates of overweight in its inhabitants. Vegetarian dietary patterns (i.e., lacto-ovo-vegetarian and vegan) are increasing in western countries, and also in Italy, where 9.5% of the population self-declared as vegetarian in 2023. Though the vegetarian diet has been associated with beneficial health effects, speculation on its alleged nutrient inadequacy exists. For this reason, we assessed the nutrient composition of the diet of 470 participants enrolled in an online survey (the INVITA study), who completed a weighted food questionnaire on three different days. Participants were divided into four dietary groups obtained according to their self-declared dietary intakes: 116 Meat Eaters (MEs), 49 Fish Eaters (FEs), 116 Lacto-Ovo-Vegetarians (LOVs), and 189 VegaNs (VNs). The mean intake of most of the main nutrients was similar among all groups and within the normal range expected for the Italian population, supporting the adequacy of diets within our Italian sample, especially the LOV and VN diet. Since the Mediterranean diet is a plant-based diet, some of its components still persist in the current Italian diet, representing a staple also for people adopting a vegetarian diet.

Zinc Toxicity: Understanding the Limits

Zinc, a vital trace element, holds significant importance in numerous physiological processes within the body. It participates in over 300 enzymatic reactions, metabolic functions, regulation of gene expression, apoptosis and immune modulation, thereby demonstrating its essential role in maintaining overall health and well-being. While zinc deficiency is associated with significant health risks, an excess of this trace element can also lead to harmful effects. According to the World Health Organization (WHO), 6.7 to 15 mg per day are referred to be the dietary reference value. An excess of the recommended daily intake may result in symptoms such as anemia, neutropenia and zinc-induced copper deficiency. The European Food Safety Authority (EFSA) defines the tolerable upper intake level (UL) as 25 mg per day, whereas the Food and Drug Administration (FDA) allows 40 mg per day. This review will summarize the current knowledge regarding the calculation of UL and other health risks associated with zinc. For example, zinc intake is not limited to oral consumption; other routes, such as inhalation or topical application, may also pose risks of zinc intoxication.

Comprehensive review on toxic heavy metals in the aquatic system: sources, identification, treatment strategies, and health risk assessment

Heavy metal pollution in water sources has become a major worldwide environmental issue, posing a threat to aquatic ecosystems and human health. The pollution of the aquatic environment is increasing as a result of industrialization, climate change, and urban development. The sources of heavy metal pollution in water include mining waste, leachates from landfills, municipal and industrial wastewater, urban runoff, and natural events such as volcanism, weathering, and rock abrasion. Heavy metal ions are toxic and potentially carcinogenic. They can also buildup in biological systems and cause bioaccumulation even at low levels of exposure, heavy metals can cause harm to organs such as the nervous system, liver and lungs, kidneys and stomach, skin, and reproductive systems. There were various approaches tried to purify water and maintain water quality. The main purpose of this article was to investigate the occurrence and fate of the dangerous contaminants (Heavy metal and metalloids) found in domestic and industrial effluents. This effluent mixes with other water streams and is used for agricultural activities and other domestic activities further complicating the issue. It also discussed conventional and non-conventional treatment methods for heavy metals from aquatic environments. Conclusively, a pollution assessment of heavy metals and a human health risk assessment of heavy metals in water resources have been explained. In addition, there have been efforts to focus on heavy metal sequestration from industrial waste streams and to create a scientific framework for reducing heavy metal discharges into the aquatic environment.

The Role of Zinc in Developed Countries in Pediatric Patients: A 360-Degree View

Zinc is an important trace element for growth and health at pediatric ages. Zinc is fundamental in inflammatory pathways, oxidative balance, and immune function. Zinc exhibits anti-inflammatory properties by modulating Nuclear Factor-kappa (NF-κB) activity and reducing histamine release from basophils, leukocytes, and mast cells. Furthermore, its antioxidant activity protects against oxidative damage and chronic diseases. Finally, zinc improves the ability to trigger effective immune responses against pathogens by contributing to the maturation of lymphocytes, the production of cytokines, and the regulation of apoptosis. Given these properties, zinc can be considered an adjunctive therapy in treating and preventing respiratory, nephrological, and gastrointestinal diseases, both acute and chronic. This review aims to deepen the role and metabolism of zinc, focusing on the role of supplementation in developed countries in pediatric diseases.

Metals on the Menu-Analyzing the Presence, Importance, and Consequences

Metals are integral components of the natural environment, and their presence in the food supply is inevitable and complex. While essential metals such as sodium, potassium, magnesium, calcium, iron, zinc, and copper are crucial for various physiological functions and must be consumed through the diet, others, like lead, mercury, and cadmium, are toxic even at low concentrations and pose serious health risks. This study comprehensively analyzes the presence, importance, and consequences of metals in the food chain. We explore the pathways through which metals enter the food supply, their distribution across different food types, and the associated health implications. By examining current regulatory standards for maximum allowable levels of various metals, we highlight the importance of ensuring food safety and protecting public health. Furthermore, this research underscores the need for continuous monitoring and management of metal content in food, especially as global agricultural and food production practices evolve. Our findings aim to inform dietary recommendations, food fortification strategies, and regulatory policies, ultimately contributing to safer and more nutritionally balanced diets.

Marginal Zinc Deficiency Promotes Pancreatic Islet Enlargement While Zinc Supplementation Improves the Pancreatic Insulin Response in Zucker Diabetic Fatty Rats

Zinc deficiency has been associated with the worsening of diabetes while zinc supplementation has been proposed to ameliorate diabetes. This study examined the effects of marginal zinc deficiency (MZD) and zinc supplementation (ZS) on obesity, glycemic control, pancreatic islets, hepatic steatosis and renal function of Zucker diabetic fatty (ZDF) rats. Male ZDF rats were fed an MZD, zinc control (ZC) or ZS diet (4, 30 and 300 mg Zn/kg diet, respectively), and lean Zucker rats were fed a ZC diet for 8 weeks. MZD and ZS did not alter body weight or whole-body composition in ZDF rats. MZD ZDF rats had reduced zinc concentrations in the femur and pancreas, a greater number of enlarged pancreatic islets and a diminished response to an oral glucose load based on a 1.8-fold greater incremental area-under-the-curve (AUC) for glucose compared to ZC ZDF. ZS ZDF rats had elevated serum, femur and pancreatic zinc concentrations, unchanged pancreatic parameters and a 50% reduction in the AUC for insulin compared to ZC ZDF rats, suggesting greater insulin sensitivity. Dietary zinc intake did not alter hepatic steatosis, creatinine clearance, or levels of proteins that contribute to insulin signaling, inflammation or zinc transport in epididymal fat. Potential adverse effects of ZS were suggested by reduced hepatic copper concentrations and elevated serum urea compared to ZC ZDF rats. In summary, ZS improved the pancreatic insulin response but not the glucose handling. In contrast, reduced zinc status in ZDF rats led to impaired glucose tolerance and a compensatory increase in the number and size of pancreatic islets which could lead to β-cell exhaustion.

A GFP Inspired 8-Methoxyquinoline-Derived Fluorescent Molecular Sensor for the Detection of Zn2+ by Two-Photon Microscopy

An effective, GFP-inspired fluorescent Zn2+ sensor is developed for two-photon microscopy and related biological application that features an 8-methoxyquinoline moiety. Excellent photophysical characteristics including a 37-fold fluorescence enhancement with excitation and emission maxima at 440 nm and 505 nm, respectively, as well as a high two-photon cross-section of 73 GM at 880 nm are reported. Based on the experimental data, the relationship between the structure and properties was elucidated and explained backed up by DFT calculations, particularly the observed PeT phenomenon for the turn-on process. Biological validation and detailed experimental and theoretical characterization of the free and the zinc-bound compounds are presented.

The effect of dietary zinc and zinc physiological status on the composition of the gut microbiome in vivo

Zinc serves critical catalytic, regulatory, and structural roles. Hosts and their resident gut microbiota both require zinc, leading to competition, where a balance must be maintained. This systematic review examined evidence on dietary zinc and physiological status (zinc deficiency or high zinc/zinc overload) effects on gut microbiota. This review was conducted according to PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines and registered in PROSPERO (CRD42021250566). PubMed, Web of Science, and Scopus databases were searched for in vivo (animal) studies, resulting in eight selected studies. Study quality limitations were evaluated using the SYRCLE risk of bias tool and according to ARRIVE guidelines. The results demonstrated that zinc deficiency led to inconsistent changes in α-diversity and short-chain fatty acid production but led to alterations in bacterial taxa with functions in carbohydrate metabolism, glycan metabolism, and intestinal mucin degradation. High dietary zinc/zinc overload generally resulted in either unchanged or decreased α-diversity, decreased short-chain fatty acid production, and increased bacterial metal resistance and antibiotic resistance genes. Additional studies in human and animal models are needed to further understand zinc physiological status effects on the intestinal microbiome and clarify the applicability of utilizing the gut microbiome as a potential zinc status biomarker.

Serum trace elements during treatment in pancreatic cancer patients and their associations with cancer prognosis

BACKGROUND & AIMS

In this study, we assessed serum trace element concentrations in patients with pancreatic cancer and compared the results to those of healthy controls and patients with chronic pancreatitis. We evaluated the association between trace element concentrations during cancer treatment and the risk of cancer progression and mortality in pancreatic cancer patients.

METHODS

A retrospective cohort study was conducted at a tertiary center in Korea. Serum trace element concentrations of cobalt (Co), copper (Cu), selenium (Se), and zinc (Zn) were measured at diagnosis using an inductively coupled plasma-mass spectrometry in 124 patients with pancreatic cancer, 50 patients with chronic pancreatitis, and 120 healthy controls. Trace elements were measured after a median of 282.5 (95% confidence interval [CI], 224.0-326.5) days from treatment initiation to assess changes in trace element concentrations during treatment.

RESULTS

Serum Co concentrations were significantly higher in patients with chronic pancreatitis and pancreatic cancer compared to healthy controls, while serum Se concentrations were significantly lower. During treatment, serum concentrations of Cu, Se, and Zn significantly decreased in patients with pancreatic cancer. During the follow-up (median 152.5; 95% CI, 142.8-160.0 months), 85.5% of patients experienced progression or relapse, and 84.7% of patients died. Patients with decreased Se and Zn concentrations during treatment had a higher mortality (hazard ratio [HR], 2.10; 95% CI, 1.31-3.38; P = 0.0020 for Se; HR, 1.72; 95% CI, 1.06-2.79; P = 0.0269 for Zn) compared to those with unchanged or increased trace element concentrations during treatment. Patients with a greater reduction in Zn concentrations during treatment had a higher mortality than those with a smaller reduction (HR, 1.59; 95% CI, 1.01-2.52; P = 0.0483). Patients whose Zn status changed from normal to deficient during treatment had an increased mortality (HR, 1.76; 95% CI, 1.16-2.67, P = 0.0084). Patients with multiple (≥2) trace element deficiencies after treatment had poorer outcomes than those with no or single trace element deficiency.

CONCLUSIONS

This study revealed that decreases in Se and Zn concentrations during cancer treatment were associated with adverse outcomes in terms of cancer progression and mortality in patients with pancreatic cancer. Further prospective investigations are recommended.

Effects of high dietary inclusion of Arthrospira platensis, either extruded or supplemented with a super-dosing multi-enzyme mixture, on broiler growth performance and major meat quality parameters

BACKGROUND

This investigation assessed the effects of high dietary inclusion of Spirulina (Arthrospira platensis) on broiler chicken growth performance, meat quality and nutritional attributes. For this, 120 male broiler chicks were housed in 40 battery brooders (three birds per brooder). Initially, for 14 days, a standard corn and soybean meal diet was administered. Subsequently, from days 14 to 35, chicks were assigned to one of the four dietary treatments (n = 10 per treatment): (1) control diet (CTR); (2) diet with 15% Spirulina (SP); (3) diet with 15% extruded Spirulina (SPE); and (4) diet with 15% Spirulina plus a super-dosing enzymes supplement (0.20% pancreatin extract and 0.01% lysozyme) (SPM).

RESULTS

Throughout the experimental period, both SP and SPM diets resulted in decreased final body weight and body weight gain compared to control (p < 0.001), with the SPE diet showing comparable results to CTR. The SPE diet prompted an increase in average daily feed intake (p = 0.026). However, all microalga treatments increased the feed conversion ratio compared to CTR. Dietary inclusion of Spirulina notably increased intestinal content viscosity (p < 0.010), which was mitigated by the SPM diet. Spirulina supplementation led to lower pH levels in breast meat 24 h post-mortem and heightened the b* colour value in both breast and thigh meats (p < 0.010). Furthermore, Spirulina contributed to an increased accumulation of total carotenoids, n-3 polyunsaturated fatty acids (PUFA), and saturated fatty acids (SFA), while diminishing n-6 PUFA, thus altering the n-6/n-3 and PUFA/SFA ratios favourably (p < 0.001). However, it also reduced zinc concentration in breast meat (p < 0.001).

CONCLUSIONS

The findings indicate that high Spirulina levels in broiler diets impair growth due to increased intestinal viscosity, and that extrusion pre-treatment mitigates this effect. Despite reducing digesta viscosity, a super-dosing enzyme mix did not improve growth. Data also indicates that Spirulina enriches meat with antioxidants and n-3 PUFA but reduces α-tocopherol and increases saturated fats. Reduced zinc content in meat suggests the need for Spirulina biofortification to maintain its nutritional value.

Role of Nutrients in Pediatric Non-Dialysis Chronic Kidney Disease: From Pathogenesis to Correct Supplementation

Nutrition management is fundamental for children with chronic kidney disease (CKD). Fluid balance and low-protein and low-sodium diets are the more stressed fields from a nutritional point of view. At the same time, the role of micronutrients is often underestimated. Starting from the causes that could lead to potential micronutrient deficiencies in these patients, this review considers all micronutrients that could be administered in CKD to improve the prognosis of this disease.

The nutritional roles of zinc for immune system and COVID-19 patients

Zinc (Zn) is a vital micronutrient that strengthens the immune system, aids cellular activities, and treats infectious diseases. A deficiency in Zn can lead to an imbalance in the immune system. This imbalance is particularly evident in severe deficiency cases, where there is a high susceptibility to various viral infections, including COVID-19 caused by SARS-CoV-2. This review article examines the nutritional roles of Zn in human health, the maintenance of Zn concentration, and Zn uptake. As Zn is an essential trace element that plays a critical role in the immune system and is necessary for immune cell function and cell signaling, the roles of Zn in the human immune system, immune cells, interleukins, and its role in SARS-CoV-2 infection are further discussed. In summary, this review paper encapsulates the nutritional role of Zn in the human immune system, with the hope of providing specific insights into Zn research.

Enhanced osteogenic and antibacterial properties of titanium implant surface modified with Zn-incorporated nanowires: Preclinical in vitro and in vivo investigations

OBJECTIVE

This study aimed to synthesize zinc-incorporated nanowires structure modified titanium implant surface (Zn-NW-Ti) and explore its superior osteogenic and antibacterial properties in vitro and in vivo.

MATERIALS AND METHODS

Zn-NW-Ti was synthesized via displacement reactions between zinc sulfate solutions and the titanium (Ti) surface, which was pretreated by hydrofluoric acid etching and hyperthermal alkalinization. The physicochemical properties of the Zn-NW-Ti surface were examined. Moreover, the biological effects of Zn-NW-Ti on MC3T3-E1 cells and its antibacterial property against oral pathogenic bacteria (Staphylococcus aureus, Porphyromonas gingivalis, and Actinobacillus actinomycetemcomitans) compared with sandblasted and acid-etched Ti (SLA-Ti) and nanowires modified Ti (NW-Ti) surface were assessed. Zn-NW-Ti and SLA-Ti modified implants were inserted into the anterior extraction socket of the rabbit mandible with or without exposure to the mixed bacterial solution (S. aureus, P. gingivalis, and A. actinomycetemcomitans) to investigate the osteointegration and antibacterial performance via radiographic and histomorphometric analysis.

RESULTS

The Zn-NW-Ti surface was successfully prepared. The resultant titanium surface appeared as a nanowires structure with hydrophilicity, from which zinc ions were released in an effective concentration range. The Zn-NW-Ti surface performed better in facilitating the adhesion, proliferation, and differentiation of MC3T3-E1 cells while inhibiting the colonization of bacteria compared with SLA-Ti and NW-Ti surface. The Zn-NW-Ti implant exhibited enhanced osseointegration in vivo, which was attributed to increased osteogenic activity and reduced bacterial-induced inflammation compared with the SLA-Ti implant.

CONCLUSIONS

The Zn-incorporated nanowires structure modified titanium implant surface exhibited improvements in osteogenic and antibacterial properties, which optimized osteointegration in comparison with SLA titanium implant surface.

Zinc Supplementation Reduces Testicular Cell Apoptosis in Mice and Improves Spermatogenic Dysfunction Caused by Marginal Zinc Deficiency

Zinc (Zn) is an important trace element in the human body and plays an important role in growth, development, and male reproductive functions. Marginal zinc deficiency (MZD) is common in the human population and can cause spermatogenic dysfunction in males. Therefore, the aim of this study was to investigate methods to improve spermatogenic dysfunction caused by MZD and to further explore its mechanism of action. A total of 75 4-week-old male SPF ICR mice were randomly divided into five groups (control, MZD, MZD + ZnY2, MZD + ZnY4, and MZD + ZnY8, 15 mice per group). The dietary Zn content was 30 mg/kg in the control group and 10 mg/kg in the other groups. From low to high, the Zn supplementation doses administered to the three groups were 2, 4, and 8 mg/kg·bw. After 35 days, the zinc content, sperm quality, activity of spermatogenic enzymes, oxidative stress level, and apoptosis level of the testes in mice were determined. The results showed that MZD decreased the level of Zn in the serum, sperm quality, and activity of spermatogenic enzymes in mice. After Zn supplementation, the Zn level in the serum increased, sperm quality was significantly improved, and spermatogenic enzyme activity was restored. In addition, MZD reduced the content of antioxidants (copper-zinc superoxide dismutase (Cu-Zn SOD), metallothionein (MT), and glutathione (GSH) and promoted malondialdehyde (MDA) production. The apoptosis index of the testis also increased significantly in the MZD group. After Zn supplementation, the level of oxidative stress decreased, and the apoptosis index in the testis was reduced. Furthermore, quantitative real-time polymerase chain reaction (qRT-PCR) showed that the expression of B-cell lymphoma-2 (Bcl-2) mRNA and Bcl-2/BCL2-associated X (Bax) in the control group decreased in testicular cells, and their expression was restored after Zn supplementation. The results of this study indicated that Zn supplementation can reduce the level of oxidative stress and increase the ability of testicular cells to resist apoptosis, thereby improving spermatogenic dysfunction caused by MZD in mice.

Minerals and the Menstrual Cycle: Impacts on Ovulation and Endometrial Health

The role of minerals in female fertility, particularly in relation to the menstrual cycle, presents a complex area of study that underscores the interplay between nutrition and reproductive health. This narrative review aims to elucidate the impacts of minerals on key aspects of the reproductive system: hormonal regulation, ovarian function and ovulation, endometrial health, and oxidative stress. Despite the attention given to specific micronutrients in relation to reproductive disorders, there is a noticeable absence of a comprehensive review focusing on the impact of minerals throughout the menstrual cycle on female fertility. This narrative review aims to address this gap by examining the influence of minerals on reproductive health. Each mineral's contribution is explored in detail to provide a clearer picture of its importance in supporting female fertility. This comprehensive analysis not only enhances our knowledge of reproductive health but also offers clinicians valuable insights into potential therapeutic strategies and the recommended intake of minerals to promote female reproductive well-being, considering the menstrual cycle. This review stands as the first to offer such a detailed examination of minerals in the context of the menstrual cycle, aiming to elevate the understanding of their critical role in female fertility and reproductive health.

Potential Drug-Nutrient Interactions of 45 Vitamins, Minerals, Trace Elements, and Associated Dietary Compounds with Acetylsalicylic Acid and Warfarin-A Review of the Literature

In cardiology, acetylsalicylic acid (ASA) and warfarin are among the most commonly used prophylactic therapies against thromboembolic events. Drug-drug interactions are generally well-known. Less known are the drug-nutrient interactions (DNIs), impeding drug absorption and altering micronutritional status. ASA and warfarin might influence the micronutritional status of patients through different mechanisms such as binding or modification of binding properties of ligands, absorption, transport, cellular use or concentration, or excretion. Our article reviews the drug-nutrient interactions that alter micronutritional status. Some of these mechanisms could be investigated with the aim to potentiate the drug effects. DNIs are seen occasionally in ASA and warfarin and could be managed through simple strategies such as risk stratification of DNIs on an individual patient basis; micronutritional status assessment as part of the medical history; extensive use of the drug-interaction probability scale to reference little-known interactions, and application of a personal, predictive, and preventive medical model using omics.

Anticancer, antioxidant, and antimicrobial studies and molecular docking of a new hexanuclear Zn(II) complex, together with its X-ray crystal analysis

A new hexanuclear Zn(II) complex with the ligand 2,2'-(piperazine-1,4-diyl)bis(ethan-1-amine), [L3Zn6(OH)6][ClO4]6·3MeOH·7H2O, was synthesized. The crystal structure of this complex showed that each Zn atom is in a distorted tetrahedral coordination environment, surrounded by two nitrogen atoms from each ligand and two hydroxide groups, each of which bridges to another Zn atom. The anticancer activities of the ligand and its metal complex against the breast cancer cell line (MCF-7) indicated that the zinc complex had a greater anticancer activity. The free ligand and its metal complex were evaluated for antioxidant activity using the DPPH scavenging method. In addition, the antibacterial activities of both compounds were screened against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The interaction of these compounds with DNA and AChE was also investigated using molecular docking.

Differential accumulation of metals in the lacustrine and fluvial Alpine bullheads (Cottus poecilopus) and recovery of fish from metal contamination after a flash flood

The spatiotemporal distribution and transport of mercury, zinc, molybdenum, rubidium, and strontium from alpine terrestrial ecosystems to alpine lake and mountain stream populations of Cottus poecilopus were investigated. Metals were measured for 66 wild fish collected from different lakes and Javorinka stream across. Mercury was measured in the pectoral fins, other elements in the skull. Bullheads contained more metals in the alpine lakes than in the mountain stream. In particular, mercury and zinc concentrations in lake bullheads were 6 and 2.5 times higher, respectively, than those of stream-dwelling fish. New data were generated on metal bioaccumulation in fish of understudied West Carpathian alpine lake environments. In July 2018, a major flood occurred in the area of the Javorinka. Already then, the mercury content in bullheads increased significantly. Bioaccumulation of mercury in fish occurred very quickly after the flood and was also significant in the following 2019. Then, the concentrations of mercury quickly decreased up to 70% in 2021-2022. Average concentrations of molybdenum and rubidium in bullheads in the stream rapidly declined in the year following the flood disturbance, but within less than 2 years, the metal levels stabilized at about the same level as in 2017 prior the flood. Strontium concentrations in fish dropped rapidly immediately after the flood, increased in the following years, and dropped again after 4 years, suggesting that many more factors are influencing strontium bioaccumulation in fish that are comparable in magnitude to the flood. The most serious warning seems to be the absence of biogenic zinc. The average concentration in the Alpine bullheads population in the stream has declined by 70% in less than 5 years and is steadily declining. An important result of this study is the demonstration that disturbance by a single factor (heavy rainfall and flooding) has a clear and timely effect on average metal concentrations in the fish population.

Role of mineral nutrients other than iron in pregnancy: under recognized opportunities to improve maternal/fetal outcomes: a literature review

BACKGROUND

Anemia during pregnancy is an important global health concern, affecting 40% of women worldwide, and iron deficiency shares a significant proportion of the burden. From conception to birth, pregnancy is a period when women undergo metabolic and physiological changes. The nutritional needs are higher during pregnancy; thus, adequate nutrition is essential to maintain fetal growth and development. However, adverse effects due to deficiency in nutrition during pregnancy can result in maternal, fetal and neonatal complications. Despite the multifactorial etiology of anemia, iron deficiency is assumed as the primary cause of anemia during pregnancy and hence, mitigation strategy pivots around it for anemia management. Therefore, excluding other contributors, a single-micronutrient approach with iron supplements remains a myopic approach and this can exacerbate iron deficiency anemia. Micronutrient deficiencies are of particular concern as they may pose a silent threat to the survival and well-being of reproductive-age women and their infants.

AIM

Micronutrients, especially trace minerals, play a myriad of roles in pregnancy, and the lack of each one causes adverse complications to both the mother and the fetus. In this review paper, we attempt to piece together available information regarding the adverse effects of abnormal trace mineral levels along with iron deficiency on the mother and the fetus.

METHOD

A non-systematic literature search in PubMed, Google Scholar, and the Cochrane databases, for publications on minerals and vitamins during pregnancy and the possible influence of supplements on pregnancy outcomes.

CONCLUSION

Micronutrient deficiency exacerbates the pregnancy-induced anemia and other adverse birth outcomes. Micronutrient supplementation during pregnancy can combat anemia as well as reduce a number of adverse pregnancy outcomes in a comprehensive manner.

Study protocol for a zinc intervention in the elderly for prevention of pneumonia, a randomized, placebo-controlled, double-blind clinical pilot trial

Pneumonia is a major public health problem for older adults, being one of the leading causes of hospitalization and death, particularly for elderly nursing home residents. We previously conducted a clinical trial in which we demonstrated that 29% of nursing home residents had low serum zinc levels coinciding with a two-fold increase in pneumonia incidence and duration in comparison to individuals with adequate serum zinc levels. However, causality could not be inferred and necessitates a double-blind clinical trial. To determine the appropriate supplementation dose for such a trial we are conducting a randomized, placebo-controlled, double-blind clinical pilot trial aimed at delineating the optimal dosage (30 and 60 mg/day elemental Zn) and establishing safety. The results from the pilot study will be leveraged to inform our larger randomized clinical trial designed to study the effect of zinc supplementation in nursing home elderly with low serum zinc levels on respiratory infections, antibiotic use, and duration of sick days with pneumonia. In tandem with dose optimization, we will evaluate the correlation between serum zinc and pan-T cell zinc levels, given that T cells and their zinc levels are important in the response and resolution of respiratory infections but whose correlation has only been extrapolated and not demonstrated. Herein we present the study rationale and protocol, as well as discuss specific challenges we encountered in securing a manufacturer for the study agents and when recruiting from nursing home populations during the COVID-19 pandemic. In light of these experiences, we provide recommendations for future clinical trials under circumstances where supply chains are disrupted, and recruitment pools are constrained or unavailable.

Clinical trial registration

https://clinicaltrials.gov/, NCT05527899.

Single nucleotide polymorphisms and Zn transport by ZIP11 shape functional phenotypes of HeLa cells

Zinc (Zn) is a vital micronutrient with essential roles in biological processes like enzyme function, gene expression, and cell signaling. Disruptions in the cellular regulation of Zn2+ ions often lead to pathological states. Mammalian Zn transporters, such as ZIP11, play a key role in homeostasis of this ion. ZIP11 resides predominately in the nucleus and Golgi apparatus. Our laboratory reported a function of ZIP11 in maintaining nuclear Zn levels in HeLa cervical cancer cells. Analyses of cervical and ovarian cancer patients' datasets identified four coding, single nucleotide polymorphisms (SNPs) in SLC39A11, the gene that encodes ZIP11, correlating with disease severity. We hypothesized that these SNPs might translate to functional changes in the ZIP11 protein by modifying access to substrate availability. We also proposed that a metal-binding site (MBS) in ZIP11 is crucial for transmembrane Zn2+ transport and required for maintenance of various pathogenic phenotypes observed in HeLa cells. Here, we investigated these claims by re-introducing single the SLC39A11 gene encoding for mutant residues associated with the SNPs, as well as MBS mutations into HeLa cells knocked down for the transporter. Some SNPs-encoding ZIP11 variants rescued Zn levels, proliferation, migration, and invasiveness of knockdown (KD) cells. Conversely, single MBS mutations mimicked the traits of KD cells, confirming the transporter's role in establishing and maintaining proliferative, migratory, and invasive traits. Overall, the intricate role of Zn in cellular dynamics and cancer progression underscores the significance of Zn transporters like ZIP11 in potential therapeutic interventions.

Current Trends on the Involvement of Zinc, Copper, and Selenium in the Process of Hepatocarcinogenesis

Numerous nutritional factors increase the risk of hepatocellular carcinoma (HCC) development. The dysregulation of zinc, copper, and selenium homeostasis is associated with the occurrence of HCC. The impairment of the homeostasis of these essential trace elements results in oxidative stress, DNA damage, cell cycle progression, and angiogenesis, finally leading to hepatocarcinogenesis. These essential trace elements can affect the microenvironment in HCC. The carrier proteins for zinc and copper and selenium-containing enzymes play important roles in the prevention or progression of HCC. These trace elements enhance or alleviate the chemosensitivity of anticancer agents in patients with HCC. The zinc, copper, or selenium may affect the homeostasis of other trace elements with each other. Novel types of cell death including ferropotosis and cupropotosis are also associated with hepatocarcinogenesis. Therapeutic strategies for HCC that target these carrier proteins for zinc and copper or selenium-containing enzymes have been developed in in vitro and in vivo studies. The use of zinc-, copper- or selenium-nanoparticles has been considered as novel therapeutic agents for HCC. These results indicate that zinc, copper, and selenium may become promising therapeutic targets in patients with HCC. The clinical application of these agents is an urgent unmet requirement. This review article highlights the correlation between the dysregulation of the homeostasis of these essential trace elements and the development of HCC and summarizes the current trends on the roles of these essential trace elements in the pathogenesis of hepatocarcinogenesis.

Microbial induced carbonate precipitation for remediation of heavy metals, ions and radioactive elements: A comprehensive exploration of prospective applications in water and soil treatment

Improper disposal practices have caused environmental disruptions, possessing by heavy metal ions and radioactive elements in water and soil, where the innovative and sustainable remediation strategies are significantly imperative in last few decades. Microbially induced carbonate precipitation (MICP) has emerged as a pioneering technology for remediating contaminated soil and water. Generally, MICP employs urease-producing microorganisms to decompose urea (NH2CONH2) into ammonium (NH4+and carbon dioxide (CO2), thereby increasing pH levels and inducing carbonate precipitation (CO32-), and effectively removing remove contaminants. Nonetheless, the intricate mechanism underlying heavy metal mineralization poses a significant challenge, constraining its application in contaminants engineering, particularly in the context of prolonged heavy metal leaching over time and its efficacy in adverse environmental conditions. This review provides a comprehensive idea of recent development of MICP and its application in environmental engineering, examining metabolic pathways, mineral precipitation mechanisms, and environmental factors as well as providing future perspectives for commercial utilization. The use of ureolytic bacteria in MICP demonstrates cost-efficiency, environmental compatibility, and successful pollutant abatement over tradition bioremediation techniques, and bio-synthesis of nanoparticles. limitations such as large-scale application, elevated Ca2+levels in groundwater, and gradual contaminant release need to be overcome. The possible future research directions for MICP technology, emphasizing its potential in conventional remediation, CO2 sequestration, bio-material synthesis, and its role in reducing environmental impact for long-term economic benefits.

Safety considerations for dietary supplement manufacturers in the United States

Due to significant dietary supplement use in the US, product manufacturers must understand the importance of implementing a robust approach to establishing safety for all ingredients, including dietary ingredients, components, and finished dietary supplement products. Different regulatory pathways exist by which the safety of dietary ingredients can be established, and thus allowed to be marketed in a dietary supplement. For individual dietary ingredients, safety information may come from a variety of sources including history of safe use, presence of the ingredient in foods, and/or non-clinical and clinical data. On occasion safety data gaps are identified for a specific ingredient, particularly those of botanical origin. Modern toxicological methods and models can prove helpful in satisfying data gaps and are presented in this review. For finished dietary supplement products, issues potentially impacting safety to consider include claims, product labeling, overages, contaminants, residual solvents, heavy metals, packaging, and product stability. In addition, a safety assessment does not end once a product is marketed. It is important that manufacturers actively monitor and record the occurrence of adverse events reported in association with the use of their products, in accordance with the law. Herein, we provide a comprehensive overview of considerations for assessing dietary supplement safety.

The Influence of Different Sustainable Substrates on the Nutritional Value of Tenebrio molitor Larvae

Every year, over 30% of food production is wasted. However, promoting a sustainable food supply not only fosters economic stability in agriculture and the food industry, but also safeguards precious natural resources and ensures universal food access and safety. Therefore, the aim of the study was to determine how specific growth conditions (utilizing by-products: sprouted potatoes (1), wheat bran (2), brewers' spent grain (3), and a control sample with agar-agar gels (4)) affect the larvae of yellow mealworms (Tenebrio molitor). This includes their nutritional and energy value, consumer sensory profiling, and technological parameters of processing. The results have indicated that larvae reared on the substrate with wheat bran had the highest energy value, at 708.26 kcal. In larvae, the difference in protein content was not significant when changing the rearing conditions, and ranged between 48.54 and 59.18%. The larvae contained a significant content of fibers, with the highest amount detected in samples with brewers' spent grain. The data indicate that glucose and arabinose were distinctive to larvae. Our study has also revealed a statistical difference in ash content between larvae and the substrate, with higher levels of nitrogen, copper, and zinc detected in the larvae compared to the substrate. We have found that the salt was naturally occurring in the substrates, with the brewers' spent grain sample having the highest amount, at 1.83%. However, the control sample yielded the highest ratings, achieving a score of 7.30 for general smell acceptability. These findings emphasize the potential of utilizing various industrial and farm by-products as substrates for mealworms, transforming them into a sustainable and nutrient-rich food source. This contribution adds to the broader discourse on nutritional value and resource efficiency.

Zinc homeostasis and redox alterations in obesity

Impairment of both cellular zinc and redox homeostasis is a feature of several chronic diseases, including obesity. A significant two-way interaction exists between redox metabolism and the relatively redox-inert zinc ion. Redox metabolism critically influences zinc homeostasis and controls its cellular availability for various cellular functions by regulating zinc exchange from/to zinc-binding proteins. Zinc can regulate redox metabolism and exhibits multiple pro-antioxidant properties. On the other hand, even minor disturbances in zinc status and zinc homeostasis affect systemic and cellular redox homeostasis. At the cellular level, zinc homeostasis is regulated by a multi-layered machinery consisting of zinc-binding molecules, zinc sensors, and two selective families of zinc transporters, the Zinc Transporter (ZnT) and Zrt, Irt-like protein (ZIP). In the present review, we summarize the current state of knowledge on the role of the mutual interaction between zinc and redox homeostasis in physiology and pathophysiology, pointing to the role of zinc in the alterations responsible for redox stress in obesity. Since zinc transporters primarily control zinc homeostasis, we describe how changes in the expression and activity of these zinc-regulating proteins are associated with obesity.

Exploring zinc deficiency using serum Zn levels: consequences and potential solutions in suckling pigs

Three trials were undertaken to provide an answer to different questions: 1) Are suckling pigs able to maintain physiological serum Zn levels throughout lactation and do these levels vary between high and low body weight (BW) pigs?, 2) Are serum Zn levels in pigs soon after weaning a predisposing factor for diarrhea?, and 3) Is it possible to increase serum Zn levels at weaning by supplementing Zn during lactation. In trial 1, blood samples were taken from pigs during lactation. Eight pigs (one piglet per litter) had blood drawn on days 0 (farrowing), 7, 14, 21, and 28 (weaning), and 60 pigs (selected from the whole farrowing batch with 35 sows), categorized as either heavy (8.63 kg) or light (5.50 kg) had blood drawn on day 28. Serum Zn levels at birth were 1.2 mg/L and decreased (P < 0.01) to 0.67 mg/L on day 28. Heavier pigs showed greater (P < 0.01) serum Zn levels (0.98 mg/L) than light BW pigs (0.79 mg/L). In trial 2, blood samples were obtained from 240 pigs at weaning (26.2 ± 2.5 d) with an average initial BW of 6.94 ± 1.87 kg and were distributed into 24 pens (10 pigs/pen) by BW. Diarrhea incidence was recorded daily from days 0 to 35 post-weaning. From the 240 pigs, a group of 110 pigs with uniform BW (6.5 ± 1.9 kg) was selected and separated into two groups based on serum Zn levels at weaning with 55 pigs with low serum Zn (LZn: <0.71 mg/L) and 55 pigs with high serum Zn (HZn: >0.9 mg/L). Pigs with LZn were 2.49 times as likely to have diarrhea as pigs with HZn (P < 0.02). In trial 3, a total of 96 suckling pigs were allotted four treatments that consisted of the daily administration of 0, 6, 18, or 30 mg of Zn as Zn citrate in capsule form during the last 7 d of lactation. Pigs were individually weighed, and blood samples were obtained on days 14, 21 (weaning), and 7 after weaning. Serum Zn levels linearly increased by day as Zn citrate supplementation increased (interaction, P < 0.001). However, only light pigs supplemented with 18 and 30 mg/L of Zn experienced an increase in serum Zn levels during lactation. In conclusion, a decrease in serum Zn levels occurs during lactation and is more severe in low BW pigs. Low Zn status (< 0.7 mg/L) at weaning may be a predisposing factor for diarrhea. However, Zn supplementation during lactation can mitigate this decrease in light pigs.

Liposomes Containing Zinc-Based Chemotherapeutic Drug Block Proliferation and Trigger Apoptosis in Breast Cancer Cells

Platinum-based chemotherapeutic drugs are effective in killing malignant cells but often trigger drug resistance or off-target side effects. Unlike platinum, zinc is used as an endogenous cofactor for several cellular enzymes and may, thus, display increased biocompatibility. In this present study, we have rationally designed and synthesized two substituted phenanthro[9,10-d]imidazole-based ligands L1 and L2 with pyridine and quinoline substitution at the 2 position and their corresponding Zn(II) complexes; (L1)2Zn and (L2)2Zn, which are characterized by standard analytical and spectroscopic methods. (L2)2Zn, but not (L1)2Zn has intrinsic fluorescence, indicating its potential utility in imaging applications. To facilitate cellular uptake, we generated liposomal formations with a phospholipid DMPC (1,2-Dimyristoyl-sn-glycero-3-phosphocholine) through molecular self-assembly. These liposomal formulations Lip-(L1)2Zn and Lip-(L2)2Zn were able to enter breast cancer cells, induce DNA fragmentation, arrest the cell cycle at the G0/G1 phase, decrease proliferation, and promote apoptosis by activating the DNA damage response. Importantly, both Lip-(L1)2Zn and Lip-(L2)2Zn decreased the size of breast cancer cell-based spheroids, indicating they may be capable of suppressing tumor growth. Our work represents an important proof-of-concept exercise demonstrating that successful liposomal formation of phenanthro[9,10-d]imidazole-based Zn(II) complexes with inherent optical properties have great promise for the development of imaging probes and efficient anticancer drugs.

Trace elements dyshomeostasis in liver and brain of weanling mice under altered dietary selenium conditions

BACKGROUND

A balanced diet containing selenium (Se) and other trace elements is essential for normal development and growth. Se has been recognized as an essential trace element; however, its interaction with other elements has not been fully investigated. In the present study, sodium (Na), magnesium (Mg), potassium (K), calcium (Ca), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), copper (Cu), zinc (Zn), Se and rubidium (Rb), were analysed in liver and brain regions under altered dietary Se intake in weanling mice to identify major discriminatory elements.

METHODS

The study investigated the effects of different levels of Se intake on the elemental composition in liver and brain tissues of weaned mice. After 24 weeks of feeding with Se adequate, deficient, and excess diets, elemental analysis was performed on the harvested tissues using Inductively coupled plasma mass spectrometry (ICP-MS). Statistical analysis that included analysis of covariance (ANCOVA), correlation coefficient analysis, principal component analysis, and partial least squares discriminant analysis were performed.

RESULTS

The ANCOVA showed statistically significant changes and correlations among the analysed elements under altered dietary Se status. The multivariate analysis showed differential changes in elements in liver and brain regions. The results suggest that long-term dietary Se alternations lead to dyshomeostasis in trace elements that are required in higher concentrations compared to Se. It was observed that changes in the Fe, Co, and Rb levels were similar in all the tissues studied, whereas the changes in Mg, Cr, and Mn levels were different among the tissues under altered dietary Se status. Additionally, the changes in Rb levels correlated with the dietary Se intake but had no relation with the tissue Se levels.

CONCLUSIONS

The findings suggest interactions between Mg, Cr, Mn, Fe, Co, and Se under altered Se status may impact cellular functions during postnatal development. However, the possible biological significance of alterations in Rb levels under different dietary Se paradigms needs to be further explored.

Zinc citrate-coated whey protein nanoparticles alleviate kidney damage and the disturbances in inflammatory gene expression in rats

This work was conducted to synthesize whey protein nanoparticles (WPNPs) for the coating of zinc citrate (Zn CITR) at three levels and to study their protective role against CCl4 -induced kidney damage and inflammatory gene expression disorder in rats. Seventy male Sprague-Dawley rats were divided into seven groups and treated orally for 4 weeks as follows; the control group, the group treated twice a week with CCl4 (5 mL/kg b.w), the groups received CCl4 plus WPNPs (300 mg/kg b.w); the group received 50 mg/kg b.w of Zn CITR or the three formulas of Zn CITR-WPNPs at low, medium and high doses (LD, MD, and HD). Blood and kidney samples were collected for different assays and histological analyses. The fabricated particles were semispherical, with an average size of 160 ± 2.7, 180 ± 3.1, and 200 ± 2.6 nm and ζ potential of -126, -93, and -84 mV for ZN CITR-WPNPs (LD), Zn CITR-WPNPs (MD), and ZN CITR-WPNPs (HD), respectively. CCl4 significantly increased (p ≤ 0.05) kidney function indices, oxidative stress markers, messenger RNA expression of transforming growth factor-β1, interleukin (IL)-1β, IL-10, IL-6, inducible nitric oxide synthase, and tumor necrosis factor-α and significantly decreased (p ≤ 0.05) renal superoxide dismutase, catalase, and glutathione peroxidase along with the histological changes in the kidney tissues. WPNPs, Zn CITR, and Zn CITR loaded WPNPS showed a protective effect against these complications and Zn CITR-WPNPs (LD) was more effective. WPNPs can be used effectively for coating Zn CITR at a level of 7 mg/g WPNPs to be used as a supplement for the protection of the kidney against different toxicants to enhance immunity and avoid harm of excess Zn.

Diet supplementation of organic zinc positively affects growth, antioxidant capacity, immune response and lipid metabolism in juvenile largemouth bass, Micropterus salmoides

Zn is an important trace element involved in various biochemical processes in aquatic species. An 8-week rearing trial was thus conducted to investigate the effects of Zn on juvenile largemouth bass (Micropterus salmoides) by feeding seven diets, respectively, supplemented with no Zn (Con), 60 and 120 mg/kg inorganic Zn (Sul60 and Sul120), and 30, 60, 90 and 120 mg/kg organic Zn (Bio30, Bio60, Bio90 and Bio120). Sul120 and Bio120 groups showed significantly higher weight gain and specific growth rate than Con group, with Bio60 group obtaining the lowest viscerosomatic index and hepatosomatic index. 60 or 90 mg/kg organic Zn significantly facilitated whole body Zn retention. Up-regulation of hepatic superoxide dismutase, glutathione peroxidase and catalase activities and decline of malondialdehyde contents indicated augmented antioxidant capacities by organic Zn. Zn treatment also lowered plasma aminotransferase levels while promoting acid phosphatase activity and hepatic transcription levels of alp1, acp1 and lyz-c than deprivation of Zn. The alterations in whole body and liver crude lipid and plasma TAG contents illustrated the regulatory effect of Zn on lipid metabolism, which could be possibly attributed to the changes in hepatic expressions of acc1, pparγ, atgl and cpt1. These findings demonstrated the capabilities of Zn in potentiating growth and morphological performance, antioxidant capacity, immunity as well as regulating lipid metabolism in M. salmoides. Organic Zn could perform comparable effects at same or lower supplementation levels than inorganic Zn, suggesting its higher efficiency. 60 mg/kg supplementation of organic Zn could effectively cover the requirements of M. salmoides.

The Effect of Zinc Supplementation on Lipid Profiles in Patients with Type 2 Diabetes Mellitus: A Systematic Review and Dose-Response Meta-Analysis of Randomized Clinical Trials

Research on the effects of zinc supplementation on lipid profiles in people with type 2 diabetes mellitus (T2DM) has been inconsistent. This systematic review and meta-analysis was performed to summarize the current data on the effects of zinc supplementation on lipid profiles in patients with T2DM. Three online databases including PubMed, Scopus, and Web of Science were searched to find relevant studies published until September 2022. The exposure was zinc supplementation, and the outcomes were low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride (TG), and total cholesterol (TC). Fourteen randomized clinical trials consisting of 1067 patients were included in the statistical analysis. Significant improvement was observed in all 4 lipid profile components. Following zinc supplementation, a significant decrease was observed in TC (weighted mean difference [WMD]: -16.16; 95% confidence interval [CI]: -26.43, -5.89; P = 0.002), LDL (WMD: -6.18; 95% CI: -9.35, -3.02; P < 0.001), and TG (WMD: -13.08; 95% CI: -21.83, -4.34; P = 0.003). After analyzing 13 studies reporting HDL, a significant increase was seen (WMD: 3.76; 95% CI: 1.30, 6.22; P = 0.003). In a nonlinear dose-response analysis, a significant inverse association was observed between <12 wk zinc supplementation and TC, LDL, and TG (TC: WMD: -5, Pnonlinearity < 0.001; LDL: WMD: -5, Pnonlinearity = 0.07, TG: WMD: -16.5, Pnonlinearity = 0.006). Nonlinear dose-response analysis shows that the optimum elemental zinc dosage for the best response to the supplementation for TC, LDL, and TG are 120, 100, and 140 mg/d, respectively (TC: WMD: -5, Pnonlinearity < 0.001; LDL: WMD: -10, Pnonlinearity = 0.006, TG: WMD: -50, Pnonlinearity = 0.031). In conclusion, we found significant changes in all 4 components of the lipid profile through zinc supplementation in T2DM patients. Based on our findings, zinc supplementation may have profound favorable consequences on the lipid profile of T2DM patients, especially in the zinc-deficient group.

Antiviral activity of zinc against hepatitis viruses: current status and future prospects

Viral hepatitis is a major public health concern globally. World health organization aims at eliminating viral hepatitis as a public health threat by 2030. Among the hepatitis causing viruses, hepatitis B and C are primarily transmitted via contaminated blood. Hepatitis A and E, which gets transmitted primarily via the feco-oral route, are the leading cause of acute viral hepatitis. Although vaccines are available against some of these viruses, new cases continue to be reported. There is an urgent need to devise a potent yet economical antiviral strategy against the hepatitis-causing viruses (denoted as hepatitis viruses) for achieving global elimination of viral hepatitis. Although zinc was known to mankind for a long time (since before Christ era), it was identified as an element in 1746 and its importance for human health was discovered in 1963 by the pioneering work of Dr. Ananda S. Prasad. A series of follow up studies involving zinc supplementation as a therapy demonstrated zinc as an essential element for humans, leading to establishment of a recommended dietary allowance (RDA) of 15 milligram zinc [United States RDA for zinc]. Being an essential component of many cellular enzymes and transcription factors, zinc is vital for growth and homeostasis of most living organisms, including human. Importantly, several studies indicate potent antiviral activity of zinc. Multiple studies have demonstrated antiviral activity of zinc against viruses that cause hepatitis. This article provides a comprehensive overview of the findings on antiviral activity of zinc against hepatitis viruses, discusses the mechanisms underlying the antiviral properties of zinc and summarizes the prospects of harnessing the therapeutic benefit of zinc supplementation therapy in reducing the disease burden due to viral hepatitis.