Vanadium: Risks and possible benefits in the light of a comprehensive overview of its pharmacotoxicological mechanisms and multi-applications with a summary of further research trends

Removal of vanadium(V) ions from acidic water using reusable manganese oxide sorbents

Manganese oxide (MnOx) was studied for its ability to adsorb vanadium (V) ions for applications in acidic water treatment. Three MnOx types: naturally-occurring (NatMnO), commercially-derived (ComMnO), and laboratory synthesised (SynMnO) were examined in batch systems under varying pH, adsorbent dosage, ionic strength, and contact time. The greatest V sorption occurred at acidic pH, following the order: NatMnO > SynMnO > ComMnO, with maximum adsorption capacities of 54.0, 26.0, and 10.4 mg/g, respectively (at pH 3.0, mass/volume ratio of 2 g/L, concentration of 100 mg/L, 24 hours). Adsorption equilibrium data best fit the Freundlich isotherm, indicating multilayer adsorption, while kinetic data followed a two-constant rate model, suggesting both physical and chemical sorption. Solution pH was found to have a significant impact, with V removal by MnOx most effective at low pH, likely due to the negative zeta potential of the MnOx under such conditions. MnOx reusability was investigated using repeated sorption and desorption experiments with 0.1 M HCl, 0.1 M NaOH, and deionised water to regenerate the MnOx. The regenerated MnOx exhibited similar or enhanced ability to sorb V ions from solution. Overall, these results confirm the unique ability of MnOx as a reusable sorbent for V removal from acidic water, while also enhancing our mechanistic understanding of the removal process. This finding supports the development of sustainable solutions for acidic water treatment, contributing to efforts to address this critical environmental challenge.

Modelling reactive transport of metals in Wujiang cascade reservoirs under coal-fired, hydro power generation and fishing ban scenarios

Coal power plants and cage aquaculture are considered as the main sources of metal pollution in damming rivers. Understanding the spatial distribution and future changes of metals in cascade reservoirs is crucial for effective water resource management. Following the implementation of increasingly rigorous environmental standards for thermal power industry and fishing bans for Yangtze River, improvement of water quality in related reservoirs at the Wujiang River- hydropower stations and coal-fired power plants system (WRHCS) is expected but remains unstudied. In this study, dissolved and particulate iron, zinc, copper, cobalt, molybdenum, selenium, chromium, manganese, nickel, vanadium, lead, arsenic, cadmium, antimony and tungsten concentrations in the cascade reservoirs of WRHCS were estimated based on a mass balance model. The transport model analyzed total suspended particulates reduction emissions of thermal power and cage aquaculture scenarios. This study found 1) 20-31 years needed to reach a steady state of metal concentrations, 2) Fe and Mn can be problematic for water quality. We suggest that aeration, phytoremediation, sediment removal, and improved watershed management practices are needed to improve the water environment of the WRHCS system. This is also conducive to the sustainable management of ubiquitous thermal power - hydropower - fisheries systems.

Antidiabetic potential of vanadium complexes combined with olive leaf extracts: a viable approach to reduce metal toxicity

Vanadium compounds are known for their antidiabetic properties due to their ability to interfere with numerous mechanisms that lead to the decrease of blood glucose levels. Although some of these compounds have reached clinical trials and have the advantage of being orally administrable, no vanadium-containing drugs are currently available on the market, primarily due to the high doses required, which can lead intestinal and renal problems in case of long-term treatments. In this study, plant extracts obtained from olive leaves (Olea europaea L.) were combined with vanadium complexes with established antidiabetic activity with the aim of reducing their metal toxicity and, at the same time, amplifying their hypoglycemic action. The extracts were characterized by chromatographic and spectroscopic methods showing a composition rich in polyphenols and a high antioxidant activity. Formulations containing a vanadium complex (bis(maltolato)oxidovanadium(IV), BMOV, or bis(picolinato)oxidovanadium(IV), BPOV) mixed with different amount of olive leaves extract were tested in vitro to evaluate intestinal toxicity and hypoglycemic activity. The results demonstrated that the plant extracts are generally non-toxic toward human colon fibroblast in the whole range of tested concentrations and some of them are particularly effective in reducing the toxicity of the two vanadium compounds. Further in vitro tests conducted on differentiated human adipocyte cell lines revealed a significant increase in glucose uptake following treatment with the mixed formulations, compared to the effect of the individual components, indicating a synergistic effect. Immunocytochemical assays suggested that the translocation of GLUT4 transporter can be involved in the mechanism of action.

Evaluation of Heavy Metals and Essential Minerals in the Hair of Children with Autism Spectrum Disorder and Their Association with Symptom Severity

The exact cause of Autism spectrum disorder (ASD) remains unclear. The accumulation of heavy metals and the imbalance of trace elements are believed to play a key role in the pathogenesis of ASD. This study aimed to compare the levels of trace elements and heavy metals in the hair of 1-16-year-old children with varying ASD severity. We included a control group of 57 children, as well as 124 children with autism, consisting of 53 with mild to moderate autism and 71 with severe autism. Questionnaires and hair samples were collected, and 21 chemical elements were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). Children with severe autism showed significantly higher levels of the trace elements copper (Cu) and heavy metals vanadium (V), cobalt (Co), nickel (Ni), arsenic (As), cadmium (Cd), and lead (Pb) in their bodies compared to the control group. Boys with severe autism showed significantly higher levels of Cu, As, Cd, and Pb compared to the control group, while girls with severe autism exhibited significantly lower levels of potassium (K) and increased levels of Pb. Severely autistic children under 7 years old had significantly increased levels of Mn, Cu, V, Co, Ni, As, Cd, and Pb. Children with severe autism aged 7-16 years typically showed significantly higher levels of Cu and As. These findings underscore the importance of heavy metals and essential minerals as environmental factors in the severity of ASD disease.

Interaction of VVO2-hydrazonates with lysozyme

Vanadium compounds (VCs) exhibit a broad range of pharmacological properties, with their most significant medical applications being in the treatment of cancer and diabetes. The therapeutic effects and mode of action of VCs may be associated with their ability to bind proteins and, consequently, understanding the VC-protein interaction is of paramount importance. Among the promising VCs, the VVO2 complex with the aroylhydrazone furan-2-carboxylic acid ((3-ethoxy-2-hydroxybenzylidene)hydrazide, hereafter denoted as VC1), deserves attention, since it exhibits cytotoxicity against various cancer cell lines, including HeLa. The interaction between VC1 and its analogue, denoted as VC2 (the dioxidovanadium(V) complex with (E)-N'-(1-(2-hydroxy-5-methoxyphenyl)ethylidene)furan-2-carbohydrazide), and hen egg white lysozyme (HEWL) was examined by UV-vis spectroscopy, fluorescence, circular dichroism, and X-ray crystallography. The interaction of VC1 and VC2 with HEWL does not alter the protein secondary and tertiary structure. Crystallographic studies indicate that the two metal complexes or V-containing fragments originating from VC1 and VC2 bind the protein via non-covalent interactions. Furthermore, when bound to HEWL, two VC1 molecules and two VC2 molecules form a supramolecular association stabilized by stacking interactions. This type of interaction could favour the binding of similar compounds to proteins and affect their biological activity.

Hybrid Materials Based on Reduced Graphene Oxide; Synthesis and Characterization of V and Ru Metal Complexes

The unique material graphene, which can find its place in many areas such as pharmaceutical industry, medical field, aviation and space industry, and elimination of environmental pollution; was obtained from graphite using strong oxidants within the scope of this study. rGO was obtained by thermal reduction of oxygen-containing groups in the GO material layer. Hybrid materials were synthesized by binding 4-aminobenzoic acid (C) and 3-aminobenzoic acid (D) to the rGO material. Ru metal complexes, which stand out with their superior photophysical properties, and V metal complexes, which are harmful to the environment and human health, were formed with the hybrid materials. The synthesized hybrid and complex materials were characterized by methods such as FTIR, UV-vis, XRD, SEM and EDX and TEM. In addition, the photoluminescence properties of the materials were analyzed. The potential of Ru and V complexes of the obtained hybrid materials for use in the environment and human health was evaluated.

Hydrolysis, Ligand Exchange, and Redox Properties of Vanadium Compounds: Implications of Solution Transformation on Biological, Therapeutic, and Environmental Applications

Vanadium is a transition metal with important industrial, technological, biological, and biomedical applications widespread in the environment and in living beings. The different reactions that vanadium compounds (VCs) undergo in the presence of proteins, nucleic acids, lipids and metabolites under mild physiological conditions are reviewed. In the environment vanadium is present naturally or through anthropogenic sources, the latter having an environmental impact caused by the dispersion of VCs in the atmosphere and aquifers. Vanadium has a versatile chemistry with interconvertible oxidation states, variable coordination number and geometry, and ability to form polyoxidovanadates with various nuclearity and structures. If a VC is added to a water-containing environment it can undergo hydrolysis, ligand-exchange, redox, and other types of changes, determined by the conditions and speciation chemistry of vanadium. Importantly, the solution is likely to differ from the VC introduced into the system and varies with concentration. Here, vanadium redox, hydrolytic and ligand-exchange chemical reactions, the influence of pH, concentration, salt, specific solutes, biomolecules, and VCs on the speciation are described. One of our goals with this work is highlight the need for assessment of the VC speciation, so that beneficial or toxic species might be identified and mechanisms of action be elucidated.

Association Between Urinary Metal Levels and Chronic Kidney Dysfunction in Rural China: A Study on Sex-Specific Differences

BACKGROUND

While current epidemiological studies have documented associations between environmental metals and renal dysfunction, the majority have concentrated on plasma metal levels. The relationship between urinary metal exposure and chronic kidney disease (CKD) remains contentious, particularly within specific demographic groups.

METHODS

This cross-sectional study included 2919 rural Chinese adults recruited between 2018 and 2019. Urine metals were measured by ICP-MS. Least absolute shrinkage and selection operator (LASSO) regression was employed to identify metals significantly associated with CKD. Then, we used binary logistic regression, along with restricted cubic spline (RCS) models, to assess the individual exposure effects of specific metals on CKD. Quantile g-computation, weighted quantile sum regression, and Bayesian kernel machine regression (BKMR) models were applied to evaluate combined effects of metal exposures on CKD. Gender-stratified analyses were also conducted to explore these associations.

RESULTS

LASSO identified seven metals (V, Cu, Rb, Sr, Ba, W, Pb) with significant impacts on CKD. In single-metal models, Cu and W exhibited a positive correlation with CKD, whereas V, Rb, Sr, Ba, and Pb showed significant negative correlations (all p < 0.05). RCS analysis revealed nonlinear associations between V, Cu, Ba, Pb, and CKD (all p-nonlinear < 0.05). In the multi-metal model, quantile-based g-computation demonstrated a collective negative association with CKD risk for the seven mixed urinary metal exposures (OR (95% CI) = -0.430 (-0.656, -0.204); p < 0.001), with V, Rb, Sr, Ba, and Pb contributing to this effect. The WQS model analysis further confirmed this joint negative association (OR (95% CI): -0.885 (-1.083, -0.899); p < 0.001), with V as the main contributor. BKMR model analysis indicated an overall negative impact of the metal mixture on CKD risk. Interactions may exist between V and Cu, as well as Cu and Sr and Pb. The female subgroup in the BKMR model demonstrated consistency with the overall association.

CONCLUSIONS

Our study findings demonstrate a negative association between the urinary metal mixture and CKD risk, particularly notable in females. Joint exposure to multiple urinary metals may involve synergistic or antagonistic interactions influencing renal function. Further research is needed to validate these observations and elucidate underlying mechanisms.

Deciphering the impact of heavy metal mixed exposure on lipid metabolism using three statistical models

Lipid metabolism disorders pose a significant threat to human health. However, the relationship between heavy metal mixed exposure and lipid metabolism remains poorly understood. This study recruited 1717 residents living near a chromium factory in northeast China. The concentrations of blood Cr, Mn, Cd, Pb, V, and serum CHOL, TG, LDL and HDL levels were measured. Generalized linear model (GLM), quantile g-computation (Qg-comp), and Bayesian kernel machine regression (BKMR) were simultaneously employed to investigate the associations between heavy metal mixed exposure and lipid markers levels. GLM analysis revealed significant associations between blood Cr concentration and HDL (β =  -0.07; 95%CI:  -0.09,  -0.05), LDL (β =  -0.06; 95%CI:  -0.11,  -0.02), and CHOL (β = 0.07; 95%CI: 0.01, 0.12) levels. V concentration was positively associated with HDL (β = 0.12; 95%CI: 0.06, 0.18) and LDL (β = 0.17; 95%CI: 0.04, 0.30) levels. Qg-comp analysis indicated a negative association between heavy metal mixed exposure and HDL (β =  -0.040; 95%CI:  -0.073,  -0.006) level. BKMR model further confirmed the negative relationship between heavy metal mixed exposure and HDL, with the interaction between blood Cr (> 1.05 μg/L) and blood V (> 5.16 μg/L) contributing to decreased HDL levels. Our findings suggested that heavy metal mixed exposure had impacts on HDL and CHOL levels, and the Cr and V may mutually play a predominant role in the observed abnormal HDL levels.

Evaluate the Work-Related Exposure of Vanadium on Scalp Hair Samples of Outdoor and Administrative Workers of Oil Drilling Field: Related Health Risks

Petrochemical facilities, including oil well drilling, are discharging resources of extensive noxious waste into the environment. The workers in different sections might be exposed to vanadium (V) through different routes (groundwater and soil), which is linked with extensive physiological disorders, hypertension, respiratory disorders, anemia, skin, and gastrointestinal disorders. This study determined the contents of V in a biological sample (scalp hair) of workers of different categories (outdoor and office workers) in an oil drilling field in Sindh, Pakistan. The environmental samples, groundwater, bottled mineral water, and soil samples were also analyzed for V. For comparative purposes, the scalp hair of age-matched male subjects residing in domestic areas of Hyderabad city, Pakistan, was also analyzed. Generally, the concentrations of V in groundwater near the oil drilling field and drilled soil illustrated significant variations. The results show that the vanadium concentration in the scalp hair of non-exposed referents (controls) and office workers (exposed referents) was 62% and 45% lower than those observed for outdoor drilling and cleaning mud workers. It was observed that high exposure to V in outdoor workers might be linked with different physiological disorders such as anemia, eye problems, and bronchial disorders.

Vanadium complexes as potential metal-based antimicrobial drugs

Radical increase of antibiotic resistance among microbes has become a serious problem for clinics all over the world that has led to the need for search of novel types of antimicrobial drugs. Each year, researchers synthesize a multitude of compounds in pursuit of identifying potential chemotherapeutic agents through diverse methodological evaluations. Among the vast array of biologically significant compounds, coordination compounds exhibit a broad range of activities within biological systems. Chelation, in particular, induces significant alterations in the biological properties of ligands and the metal component, contributing to their efficacy. Chelation increases the lipophilicity of metal complexes as a result of which they are easily absorbed by the microorganisms, thus leading to their easy passage across cell membrane. The research and development in the field of metallodrugs can be advantageous to overcome the problem encountered in antibiotic resistance. The multifaceted involvement of vanadium relative to other biometals within biological systems, coupled with its comparatively lower toxicity, underscores its utility in the advancement of novel metal-based therapeutic agents. This review aims to delineate the biological significance of V(V/IV/III) complexes as antimicrobial agents. The amassed data indicate a correlation between the potency of vanadium complexes as antimicrobial agents and the oxidation state of the metal, with III being the least toxic and V representing the most toxic oxidation state of vanadium.

An encounter between metal ions and natural products: natural products-coordinated metal ions for the diagnosis and treatment of tumors

Natural products-coordinated metal ions to form the nanomedicines are in the spotlight for cancer therapy. Some natural products could be coordinated with metal ions forming nanomedicines via simple and green environmental self-assembly, which not only improved the bioavailability of natural products, but also conferred multiple therapeutic modalities and multimodal imaging. On the one hand, in the weak acidity, glutathione (GSH) and hydrogen peroxide (H2O2) overexpression of tumor microenvironment (TME), such carrier-free nanomedicines could be further enhanced the therapeutic effect via optimizing the species of metal ions. On the other hand, nanomedicines could exert the precise treatment of tumor under the guidance of multiple imaging. Hence, this review summarized the research progress in recent years on the application of natural product-coordinated metal ions in cancer therapy. In addition, the prospects and challenges for the application of natural product-coordinated metal ions were discussed, especially how to improve targeting ability and stability and assess the safety of metal ions, so as to facilitate the clinical translation and application of natural product-coordinated metal ions nanomedicines.

Combination therapy enhances efficacy and overcomes toxicity of metal-based anti-diabetic agent

BACKGROUND AND PURPOSE

Metal-based therapeutic agents are limited by the required concentration of metal-based agents. Hereby, we determined if combination with 17β-oestradiol (E2) could reduce such levels and the therapy still be effective in type 2 diabetes mellitus (T2DM).

EXPERIMENTAL APPROACH

The metal-based agent (vanadyl acetylacetonate [VAC])- 17β-oestradiol (E2) combination is administered using the membrane-permeable graphene quantum dots (GQD), the vehicle, to form the active GQD-E2-VAC complexes, which was characterized by fluorescence spectra, infrared spectra and X-ray photoelectron spectroscopy. In db/db type 2 diabetic mice, the anti-diabetic effects of GQD-E2-VAC complexes were evaluated using blood glucose levels, oral glucose tolerance test (OGTT), serum insulin levels, homeostasis model assessment (homeostasis model assessment of insulin resistance [HOMA-IR] and homeostasis model assessment of β-cell function [HOMA-β]), histochemical assays and western blot.

KEY RESULTS

In diabetic mice, GQD-E2-VAC complex had comprehensive anti-diabetic effects, including control of hyperglycaemia, improved insulin sensitivity, correction of hyperinsulinaemia and prevention of β-cell loss. Co-regulation of thioredoxin interacting protein (TXNIP) activation by the combination of metal complex and 17β-oestradiol contributed to the enhanced anti-diabetic effects. Furthermore, a potent mitochondrial protective antioxidant, coniferaldehyde, significantly potentiates the protective effects of GQD-E2-VAC complexes.

CONCLUSION AND IMPLICATIONS

A metal complex-E2 combinatorial approach achieved simultaneously the protection of β cells and insulin enhancement at an unprecedented low dose, similar to the daily intake of dietary metals in vitamin supplements. This study demonstrates the positive effects of combination and multi-modal therapies towards type 2 diabetes treatment.

Toxicological evaluation of vanadium and derivation of a parenteral tolerable intake value for medical devices

Vanadium is used in alloys, batteries as well as catalyst and is a known impurity in medical devices and pharmaceuticals. The present work describes the calculation of a parenteral tolerable intake (TI) for vanadium by chronic exposure in implantable medical devices per ISO 10993-17:2023, the applicable standard. The 2023 update of ISO 10993-17 [1] introduces new uncertainty factors (UFs) for calculating a TI. Therefore, we noted differences between the ISO guidance and the ICH Q3D guidance on Permissible Daily Exposure (PDE) for parental elemental pharmaceutical impurities. We derived a TI of 0.20 μg V/kg/day based on the updated ISO guidance, and a PDE of 0.24 μg V/kg/day based on ICH guidance. The latter is considered a more realistic estimate.

Protein-Protein Stabilization in VIVO/8-Hydroxyquinoline-Lysozyme Adducts

The binding of the potential drug [VIVO(8-HQ)2], where 8-HQ is 8-hydroxyquinolinato, with hen egg white lysozyme (HEWL) was evaluated through spectroscopic (electron paramagnetic resonance, EPR, and UV-visible), spectrometric (electrospray ionization-mass spectrometry, ESI-MS), crystallographic (X-ray diffraction, XRD), and computational (DFT and docking) studies. ESI-MS indicates the interaction of [VIVO(8-HQ)(H2O)]+ and [VIVO(8-HQ)2(H2O)] species with HEWL. Room temperature EPR spectra suggest both covalent and non-covalent binding of the two different V-containing fragments. XRD analyses confirm these findings, showing that [VIVO(8-HQ)(H2O)]+ interacts covalently with the solvent exposed Asp119, while cis-[VIVO(8-HQ)2(H2O)] non-covalently with Arg128 and Lys96 from a symmetry mate. The covalent binding of [VIVO(8-HQ)(H2O)]+ to Asp119 is favored by a π-π contact with Trp62 and a H-bond with Asn103 of a symmetry-related molecule. Additionally, the covalent binding of VVO2 + to Asp48 and non-covalent binding of other V-containing fragments to Arg5, Cys6, and Glu7 are revealed. Molecular docking indicates that, in the absence of the interactions occurring at the protein-protein interface close to Asp119, the covalent binding to Glu35 or Asp52 should be preferred. Such a protein-protein stabilization could be more common than what believed up today, at least in the solid state, and should be considered in the characterization of metal-protein adducts.

Theoretical, antioxidant, antidiabetic and in silico molecular docking and pharmacokinetics studies of heteroleptic oxovanadium(IV) complexes of thiosemicarbazone-based ligands and diclofenac

A series of new heteroleptic oxovanadium(IV) complexes with the general formula [VOL1-6(Dcf)] (1-6), where L1-6 = thiosemicarbazone (TSC)-based ligands and Dcf = diclofenac have been synthesized and characterized. The spectral studies along with the density functional theory calculations evidenced the distorted square-pyramidal geometry around oxovanadium(IV) ion through imine nitrogen and thione sulfur atoms of TSC moiety, and two asymmetric carboxylate oxygen atoms of diclofenac drug. The complexes were evaluated for in vitro antioxidant activity using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2'-diphenyl-1-picrylhydrazyl (DPPH), hydrogen peroxide (H2O2) and superoxide radical scavenging assays with respect to the standard antioxidant drugs butylated hydroxyanisole (BHA) and rutin. The in vitro antidiabetic activity of the complexes was tested with enzymes such as α-amylase, α-glucosidase and glucose-6-phosphatase. The complexes containing methyl substituent showed higher activity than that containing the nitro substituent due to the electron-donating effect of methyl group. The in silico molecular docking studies of the oxovanadium(IV) complexes with α-amylase and α-glucosidase enzymes showed strong interaction via hydrogen bonding and hydrophobic interactions. The dynamic behavior of the proposed complexes was analyzed by molecular dynamics (MDs) simulations, which revealed the stability of docked structures with α-amylase and α-glucosidase enzymes. The in silico physicochemical and pharmacokinetics parameters, such as Lipinski's 'rule of five', Veber's rule and absorption, distribution, metabolism and excretion (ADME) properties predicted non-toxic, non-carcinogenic and safe oral administration of the synthesized complexes.Communicated by Ramaswamy H. Sarma.

Effects of exposure to multiple metallic elements in the first trimester of pregnancy on the risk of preterm birth

Exposure to certain heavy metals has been demonstrated to be associated with a higher risk of preterm birth (PTB). However, studies focused on the effects of other metal mixtures were limited. A nested case‒control study enrolling 94 PTB cases and 282 controls was conducted. Metallic elements were detected in maternal plasma collected in the first trimester using inductively coupled plasma‒mass spectrometry. The effect of maternal exposure on the risk of PTB was investigated using logistic regression, least absolute shrinkage and selection operator, restricted cubic spline (RCS), quantile g computation (QGC) and Bayesian kernel machine regression (BKMR). Vanadium (V) and arsenic (As) were positively associated with PTB risk in the logistic model, and V remains positively associated in the multi-exposure logistic model. QGC analysis determined V (69.42%) and nickel (Ni) (70.30%) as the maximum positive and negative contributors to the PTB risk, respectively. BKMR models further demonstrated a positive relationship between the exposure levels of the mixtures and PTB risk, and V was identified as the most important independent variable among the elements. RCS analysis showed an inverted U-shape effect of V and gestational age, and plasma V more than 2.18 μg/L was considered a risk factor for shortened gestation length. Exposure to metallic elements mixtures consisting of V, As, cobalt, Ni, chromium and manganese in the first trimester was associated with an increased risk of PTB, and V was considered the most important factor in the mixtures in promoting the incidence of PTB.

Ecotoxicological, ecological, and human health risks of total carbohydrates and some inorganic pollutants on the Nile Delta region along the Egyptian Mediterranean Coast

This is one of few studies dealing with the potential impact of total carbohydrates (TCHO), and some inorganic pollutants (F, B, As, V, Se) on human health. Additionally, the latter pollutants toxicological and ecological effects on the Egyptian Mediterranean Coast, especially, the Nile Delta region, were investigated. Both F (0.18 ± 0.09 mg/g) and As (2.47 ± 5.39 μg/g) were of lower concentrations compared to previous reports. Values of all ecological and ecotoxicity indices, particularly, the risk quotient (RQ), showed that arsenic had the most adverse biological effects on three trophic levels (algae, invertebrates, and fish). Children and adults non-carcinogenic hazard index (HI) values were <1, revealing that sediments in the studied area would pose no risk to humans. However, arsenic carcinogenic risk (CR) values exceeded the maximum permissible limits, implying risk to children and adults. These findings could anticipate toxic impacts of polluted effluents on the Nile Delta region.

Hydrazone-flavonol based oxidovanadium(V) complexes: Synthesis, characterization and antihyperglycemic activity of chloro derivative in vivo

Wet synthesis approach afforded four new heteroleptic mononuclear neutral diamagnetic oxidovanadium(V) complexes, comprising salicylaldehyde-based 2-furoic acid hydrazones and a flavonol coligand of the general composition [VO(fla)(L-ONO)]. The complexes were comprehensively characterized, including chemical analysis, conductometry, infrared, electronic, and mass spectroscopy, as well as 1D 1H and proton-decoupled 13C(1H) NMR spectroscopy, alongside extensive 2D 1H1H COSY, 1H13C HMQC, and 1H13C HMBC NMR analyses. Additionally, the quantum chemical properties of the complexes were studied using Gaussian at the B3LYP, HF, and M062X levels on the 6-31++g(d,p) basis sets. The interaction of these hydrolytically inert vanadium complexes and the BSA was investigated through spectrofluorimetric titration, synchronous fluorimetry, and FRET analysis in a temperature-dependent manner, providing valuable thermodynamic insights into van der Waals interactions and hydrogen bonding. Molecular docking was conducted to gain further understanding of the specific binding sites of the complexes to BSA. Complex 2, featuring a 5-chloro-substituted salicylaldehyde component of the hydrazone, was extensively examined for its biological activity in vivo. The effects of complex administration on biochemical and hematological parameters were evaluated in both healthy and diabetic Wistar rats, revealing antihyperglycemic activity at millimolar concentration. Furthermore, histopathological analysis and bioaccumulation studies of the complex in the brain, kidneys, and livers of healthy and diabetic rats revealed the potential for further development of vanadium(V) hydrazone complexes as antidiabetic and insulin-mimetic agents.

Selenium Species in Diabetes Mellitus Type 2

Selenium is an important trace element for humans and animals as it plays a key role in several major metabolic pathways. Several studies were conducted to better understand the role of selenium against diabetes mellitus (DM), particularly type 2 (T2DM), but the obtained conclusions are contradictory. A simple linear relationship does not exist between the risk of T2DM and selenium levels but is best represented in a dose-dependent manner, getting often the U-graph. This relation also depends on selenium chemical forms that are present in a diet or supplements. Both too low and too high selenium intakes could increase the risk of diabetes. Moreover, the baseline status of Se should be taken into consideration to avoid over-supplementation. The focus of this brief overview is to report the recent updates concerning selenium participation in diabetes mellitus.

Towards prolonging ovarian reproductive life: Insights into trace elements homeostasis

Ovarian aging is marked by a reduction in the quantity and quality of ovarian follicles, leading to a decline in female fertility and ovarian endocrine function. While the biological characteristics of ovarian aging are well-established, the exact mechanisms underlying this process remain elusive. Recent studies underscore the vital role of trace elements (TEs) in maintaining ovarian function. Imbalances in TEs can lead to ovarian aging, characterized by reduced enzyme activity, hormonal imbalances, ovulatory disorders, and decreased fertility. A comprehensive understanding of the relationship between systemic and cellular TEs balance and ovarian aging is critical for developing treatments to delay aging and manage age-related conditions. This review consolidates current insights into TEs homeostasis and its impact on ovarian aging, assesses how altered TEs metabolism affects ovarian aging, and suggests future research directions to prolong ovarian reproductive life. These studies are expected to offer novel approaches for mitigating ovarian aging.

Emerging Topics in Metal Complexes: Pharmacological Activity

This Special Issue (SI), "Emerging Topics in Metal Complexes: Pharmacological Activity", includes reports updating our knowledge on metals with multidirectional biological properties and metal-containing compounds/complexes for their potential therapeutic applications, with a focus on strategies improving their pharmacological features [...].

In vitro assessment of cytotoxicity of spent fluid catalytic cracking refinery catalysts on cell lines and identification of critical toxic metals

The Purpose of the present study was to quantify the responses of ten cell lines (HeLa, HepG2, HEK293, MDA-MB-231, A498, A549, A357, 3 T3, BALB-C3 T3, and NIH-3 T3) to spent fluid catalytic cracking catalysts (SFCCCs) from different petroleum refineries, and relate these responses to metal concentrations of SFCCC leachates (SFCCCLs). Cytotoxicity of SFCCCs were significantly different depending on cell lines. A357 and 3 T3 cell were the most sensitive, and A498 and HeLa cells were the least sensitive. HEK293 cells showed the least fluctuation in toxic response to different SFCCCLs among all cells. Cytotoxic IC50 values of SFCCCs to 7 kinds of cells were the most correlated with vanadium (V) concentration in SFCCCLs. V is the most critical toxic factor of SFCCC. Glutathione synthesis was induced in HepG2 cells exposed to higher concentrations of SFCCCLs. SFCCCLs with low concentration of V can induce the decrease of GSH/GSSG ratio in HepG2 cells, suggesting that high concentration of V inhibits the detoxification of glutathione.

Micronutrient Deficiency May Be Associated with the Onset of Chalkbrood Disease in Honey Bees

Chalkbrood is a disease of honey bee brood caused by the fungal parasite Ascosphaera apis. Many factors such as genetics, temperature, humidity and nutrition influence the appearance of clinical symptoms. Poor nutrition impairs the immune system, which favors the manifestation of symptoms of many honey bee diseases. However, a direct link between dietary ingredients and the symptoms of chalkbrood disease has not yet been established. We show here that the elemental composition of chalkbrood mummies and healthy larvae from the same infected hives differ, as well as that mummies differ from larvae from healthy hives. Chalkbrood mummies had the highest concentration of macroelements such as Na, Mg, P, S, K and Ca and some microelements such as Rb and Sn, and at the same time the lowest concentration of B, As, Sr, Ag, Cd, Sb, Ba and Pb. Larvae from infected hives contained less Pb, Ba, Cs, Sb, Cd, Sr, As, Zn, Cu, Ni, Co, Mn, Cr, V and Al in contrast to healthy larvae from a disease-free apiary. This is the first study to demonstrate such differences, suggesting that an infection alters the larval nutrition or that nutrition is a predisposition for the outbreak of a chalkbrood infection. Though, based on results obtained from a case study, rather than from a controlled experiment, our findings stress the differences in elements of healthy versus diseased honey bee larvae.

A Non-Toxic Binuclear Vanadium(IV) Complex as Insulin Adjuvant Improves the Glycemic Control in Streptozotocin-Induced Diabetic Rats

Diabetes mellitus (DM) complications are a burden to health care systems due to the associated consequences of poor glycemic control and the side effects of insulin therapy. Recently. adjuvant therapies, such as vanadium compounds, have gained attention due to their potential to improve glucose homeostasis in patients with diabetes. In order to determine the anti-diabetic and antioxidant effects of the oxidovanadium(IV) complex (Et3NH)2[{VO(OH}2)(ox)2(µ-ox)] or Vox2), rats with streptozotocin (STZ)-induced diabetes were treated with 30 and 100 mg/kg of Vox2, orally administered for 12 days. Vox2 at 100 mg/kg in association with insulin caused a 3.4 times decrease in blood glucose in STZ rats (424 mg/dL), reaching concentrations similar to those in the normoglycemic animals (126 mg/dL). Compared to insulin alone, the association with Vox2 caused an additional decrease in blood glucose of 39% and 65% at 30 and 100 mg/kg, respectively, and an increased pancreatic GSH levels 2.5 times. Vox2 alone did not cause gastrointestinal discomfort, diarrhea, and hepatic or renal toxicity and was not associated with changes in blood glucose level, lipid profile, or kidney or liver function. Our results highlight the potential of Vox2 in association with insulin in treating diabetes.

Cytotoxicity of vanadium dioxide nanoparticles to human embryonic kidney cell line: Compared with vanadium(IV/V) ions

Vanadium dioxide (VO2) is a class of thermochromic material with potential applications in various fields. Massive production and wide application of VO2 raise the concern of its potential toxicity to human, which has not been fully understood. Herein, a commercial VO2 nanomaterial (S-VO2) was studied for its potential toxicity to human embryonic kidney cell line HEK293, and two most common vanadium ions, V(IV) and V(V), were used for comparison to reveal the related mechanism. Our results indicate that S-VO2 induces dose-dependent cellular viability loss mainly through the dissolved V ions of S-VO2 outside the cell rather than S-VO2 particles inside the cell. The dissolved V ions of S-VO2 overproduce reactive oxygen species to trigger apoptosis and proliferation inhibition via several signaling pathways of cell physiology, such as MAPK and PI3K-Akt, among others. All bioassays indicate that the differences in toxicity between S-VO2, V(IV), and V(V) in HEK293 cells are very small, supporting that the toxicity is mainly due to the dissolved V ions, in the form of V(V) and/or V(IV), but the V(V)'s behavior is more similar to S-VO2 according to the gene expression analysis. This study reveals the toxicity mechanism of nanosized VO2 at the molecular level and the role of dissolution of VO2, providing valuable information for safe applications of vanadium oxides.

Polyoxidovanadates a new therapeutic alternative for neurodegenerative and aging diseases

Aging is a natural phenomenon characterized by a progressive decline in physiological integrity, leading to a deterioration of cognitive function and increasing the risk of suffering from chronic-degenerative diseases, including cardiovascular diseases, osteoporosis, cancer, diabetes, and neurodegeneration. Aging is considered the major risk factor for Parkinson's and Alzheimer's disease develops. Likewise, diabetes and insulin resistance constitute additional risk factors for developing neurodegenerative disorders. Currently, no treatment can effectively reverse these neurodegenerative pathologies. However, some antidiabetic drugs have opened the possibility of being used against neurodegenerative processes. In the previous framework, Vanadium species have demonstrated a notable antidiabetic effect. Our research group evaluated polyoxidovanadates such as decavanadate and metforminium-decavanadate with preventive and corrective activity on neurodegeneration in brain-specific areas from rats with metabolic syndrome. The results suggest that these polyoxidovanadates induce neuronal and cognitive restoration mechanisms. This review aims to describe the therapeutic potential of polyoxidovanadates as insulin-enhancer agents in the brain, constituting a therapeutic alternative for aging and neurodegenerative diseases.

Anticancer Metallocenes and Metal Complexes of Transition Elements from Groups 4 to 7

With the progression in the field of bioinorganic chemistry, the role of transition metal complexes as the most widely used therapeutics is becoming a more and more attractive research area. The complexes of transition metals possess a great variety of attractive pharmacological properties, including anticancer, anti-inflammatory, antioxidant, anti-infective, etc., activities. Transition metal complexes have proven to be potential alternatives to biologically active organic compounds, especially as antitumor agents. The performance of metal coordination compounds in living systems is anticipated to differ generally from the action of non-metal-containing drugs and may offer unique diagnostic and/or therapeutic opportunities. In this review, the rapid development and application of metallocenes and metal complexes of elements from Groups 4 to 7 in cancer diagnostics and therapy have been summarized. Most of the heavy metals discussed in the current review are newly discovered metals. That is why the use of their metal-based compounds has attracted a lot of attention concerning their organometallic and coordination chemistry. All of this imposes more systematic studies on their biological activity, biocompatibility, and toxicity and presupposes further investigations.

Implications of albumin in cell culture media on the biological action of vanadates(V)

In this article, the implications of binding competition of vanadates(V) with dodecyl sulfates for bovine serum albumin on cytotoxicity of vanadium(V) species against prostate cancer cells have been investigated. The pH- and SDS-dependent vanadate(V)-BSA interactions were observed. At pH 5, there is only one site capable of binding ten vanadates(V) ions (logK(ITC)1 = 4.96 ± 0.06; ΔH(ITC)1 = -1.04 ± 0.03 kcal mol-1), whereas at pH 7 two distinctive binding sites on protein were found, saturated with two and seven V(V) ions, respectively (logK(ITC)1 = 6.11 ± 0.06; ΔH(ITC)1 = 0.78 ± 0.12 kcal mol-1; logK(ITC)2 = 4.80 ± 0.02; ΔH(ITC)2 = - 4.95 ± 0.14 kcal mol-1). SDS influences the stoichiometry and the stability of the resulting V(V)-BSA complexes. Finally, the cytotoxicity of vanadates(V) against prostate cancer cells (PC3 line) was examined in the presence and absence of SDS in the culture medium. In the case of a 24-h incubation with 100 μM vanadate(V), a ca. 20 % reduction in viability of PC3 cells was observed in the presence of SDS. However, in other considered cases (various concentrations and time of incubation) SDS does not affect the dose-dependent action of vanadates(V) on the investigated prostate cancer cells.

Spectrophotometric determination of trace vanadium in fresh fruit juice samples by ion pair-based surfactant-assisted microextraction procedure with solidification of floating organic drop

An ion pair-based surfactant-assisted dispersive liquid-liquid microextraction with solidification of floating organic drop (IP-SA-DLLME-SFOD) was developed for extraction of vanadium followed by spectrophotometric determination. Tannic acid (TA) and cetyl trimethylammonium bromide (CTAB) were utilized as complexing and ion-pairing agents, respectively. Using ion-pairing, TA-vanadium complex became more hydrophobic and quantitatively extracted into 1-undecanol. Some factors that influence extraction efficiency were studied. Under optimized circumstances, the detection and quantification limits were 1.8 μg L-1 and 5.9 μg L-1, respectively. The method was linear up to 1000 μg L-1 and the enrichment factors was 19.8. For 100 μg L-1 vanadium, the intra-day, and inter-days relative standard deviations (n = 8) were 1.4% and 1.8%, respectively. The suggested IP-SA-DLLME-SFOD procedure has been effectively implemented for spectrophotometric quantification of vanadium in fresh fruit juice samples. Finally, the greenness of the approach was estimated using Analytical Greenness Calculator (AGREE), which proved its environmental friendliness and safety.

Inhibition of calcium imbalance protects hepatocytes from vanadium exposure-induced inflammation by mediating mitochondrial-associated endoplasmic reticulum membranes in ducks

Vanadium (V) is an essential mineral element in animals, but excessive V can lead to many diseases, affecting the health of humans and animals. However, the molecular crosstalk between mitochondria-associated endoplasmic reticulum membranes (MAMs) and inflammation under V exposure is still at the exploratory stage. This study was conducted to determine the molecular crosstalk between MAMs and inflammation under V exposure in ducks. In this study, duck hepatocytes were treated with NaVO3 (0 μM, 100 μM, and 200 μM) and 2-aminoethyl diphenyl borate (2-APB) (IP3R inhibitor) alone or in combination for 24 h. The data showed that V exposure-induced cell vacuolization, enlarged intercellular space, and decreased density and viability. Meanwhile, hydrogen peroxide (H2O2), malonaldehyde (MDA), catalase (CAT), superoxide dismutase (SOD), and reactive oxygen species (ROS) levels were upregulated under V treatment. In addition, excessive V could lead to a marked reduction in the MAMs structure, destruction of the membrane structure and overload of intracellular Ca2+ and mitochondrial Ca2+. Moreover, V treatment resulted in notable upregulation of the levels of MAMs-relevant factors (IP3R, Mfn2, Grp75, MCU, VDAC1) but downregulated the levels of IL-18, IL-1β, and lactate dehydrogenase (LDH) in the cell supernatant. Additionally, it also significantly elevated the levels of inflammation-relevant factors (NLRP3, ASC, caspase-1, MAVS, IL-18, IL-1β, and TXNIP). However, the inhibition of IP3R expression attenuated the V-induced variations in the above indicators. Collectively, our results revealed that the maintenance of calcium homeostasis could protect duck hepatocytes from V-induced inflammation injury via MAMs.

Metal ions as effectual tools for cancer with traditional Chinese medicine

Malignant tumor has become a major threat affecting human health, and is one of the main causes of human death. Recent studies have shown that many traditional Chinese medicines (TCM) have good anti-tumor activity, which may improve the therapeutic effect of routine treatment and quality of life with lower toxicity. However, the efficacy of TCM alone for the treatment of tumors is limited. Metal ions are essential substances for maintaining normal physiological activities. This article summarized the multiple mechanisms in which metal ions are involved in the prevention and treatment of tumors in TCM.

Evaluation of immunotoxicity of sodium metavanadate following drinking water exposure in female B6C3F1/N mice in a 28-day study

Sodium metavanadate (NaVO3 ) is a pentavalent vanadium compound used in the metal industry and dietary supplements; human exposure occurs through inhalation of fumes and dust and ingestion of NaVO3 -containing products. The objective of this study was to assess the potential immunotoxicity of NaVO3 . Female B6C3F1/N mice were exposed to 0-500 ppm NaVO3 in drinking water for 28 days and evaluated for effects on immune cell populations and innate, cellular-mediated, and humoral-mediated immunity. There was a decreasing trend in body weight (BW) and BW gain in NaVO3 exposed mice, with a decrease (p ≤ 0.05) in BW gain at ≥250 ppm, relative to control. Conversely, increasing trends in spleen weights and an increase (p ≤ 0.05) in the spleen:BW ratio at ≥250 ppm NaVO3 were observed. NaVO3 exposure altered antibody production against sheep red blood cells (SRBC). Antibody forming cells (AFC)/106 spleen cells exhibited a decreasing trend, with a decrease (p ≤ 0.05) at 500 ppm NaVO3 , concurrent with an increase in percent B cells. NaVO3 had no effect on the serum anti-SRBC IgM antibody titers or anti-keyhole limpet hemocyanin antibody production. Exposure to NaVO3 decreased the percentage of natural killer cells at all dose levels (p ≤ 0.05), with no effect on the lytic activity. NaVO3 altered T-cell populations at 500 ppm but had no effect on T-cell proliferative responses or the lytic activity of cytotoxic T cells. Collectively, these data indicate that NaVO3 exposure can adversely affect the immune system by inducing alterations in humoral-mediated immunity, specifically the AFC response, with no effect on cell-mediated or innate immunity.

Vanadium Compounds with Antidiabetic Potential

Over the last four decades, vanadium compounds have been extensively studied as potential antidiabetic drugs. With the present review, we aim at presenting a general overview of the most promising compounds and the main results obtained with in vivo studies, reported from 1899-2023. The chemistry of vanadium is explored, discussing the importance of the structure and biochemistry of vanadate and the impact of its similarity with phosphate on the antidiabetic effect. The spectroscopic characterization of vanadium compounds is discussed, particularly magnetic resonance methodologies, emphasizing its relevance for understanding species activity, speciation, and interaction with biological membranes. Finally, the most relevant studies regarding the use of vanadium compounds to treat diabetes are summarized, considering both animal models and human clinical trials. An overview of the main hypotheses explaining the biological activity of these compounds is presented, particularly the most accepted pathway involving vanadium interaction with phosphatase and kinase enzymes involved in the insulin signaling cascade. From our point of view, the major discoveries regarding the pharmacological action of this family of compounds are not yet fully understood. Thus, we still believe that vanadium presents the potential to help in metabolic control and the clinical management of diabetes, either as an insulin-like drug or as an insulin adjuvant. We look forward to the next forty years of research in this field, aiming to discover a vanadium compound with the desired therapeutic properties.

Fibroblast Cell Responses to Vanadium and Niobium Titanium Alloys: A Biocompatibility Study

The interactions of a biomaterial with tissues must be determined for the material to be fully compatible with the body for a long time. The tissue and environment where the material is implanted are highly affected by its content. Titanium-6Aluminum-4Vanadium is widely used in orthopedics and dentistry. Recently, Titanium-6Aluminum-7Niobium alloys have been studied because of Titanium-6Aluminum-4Vanadium toxicity, which may be caused by vanadium. The aim of this study was to determine whether Titanium-6Aluminum-4Vanadium and Titanium-6Aluminum-7Niobium affect fibroblast cell proliferation, mineralization, and collagen production and whether they change the expression of type 1 collagen and fibronectin genes. It was determined that the niobium-containing alloy increased cell proliferation and calcium mineralization compared with the vanadium-containing alloy (p < 0.05). However, the alloys did not cause changes in the expression of collagen type 1 or fibronectin in cells. The collagen content of the cells on the niobium-containing alloy was lower than that on both the vanadium-containing alloy and tissue culture plate surface (p < 0.05). The niobium-containing alloy was found to be superior to the vanadium-containing alloy in terms of cell proliferation and calcium mineralization. Furthermore, neither vanadium-containing alloy nor niobium-containing alloy implant materials altered gene expression. Although both alloys are considered compatible with bone tissue, it should be considered whether they are also biocompatible with fibroblast cells.

In Vitro, Oral Acute, and Repeated 28-Day Oral Dose Toxicity of a Mixed-Valence Polyoxovanadate Cluster

Polyoxovanadates (POV) are a subgroup of polyoxometalates (POM), which are nanosized clusters with reported biological activities. This manuscript describes the first toxicity evaluation of a mixed-valence polyoxovanadate, pentadecavanadate, (Me4N)6[V15O36Cl], abbreviated as V15. Cytotoxicity experiments using peripheral blood mononuclear cells (PBMC), larvae of Artemia salina Leach, and in vivo oral acute and repeated 28-day doses in mice was carried out. The LC50 values in PBMC cells and A. salina were 17.5 ± 5.8 μmol L-1, and 17.9 µg L-1, respectively, which indicates high cytotoxic activity. The toxicity in mice was not observed upon acute exposure in a single dose, however, the V15 repeated 28-day oral administration demonstrated high toxicity using 25 mg/kg, 50 mg/kg and, 300 mg/kg doses. The biochemical and hematological analyses during the 28-day administration of V15 showed significant alteration of the metabolic parameters related to the kidney and liver, suggesting moderate toxicity. The V15 toxicity was attributed to the oxidative stress and lipid peroxidation, once thiobarbituric acid (TBAR) levels significantly increased in both males and females treated with high doses of the POV and also in males treated with a lower dose of the POV. This is the first study reporting a treatment-related mortality in animals acutely administrated with a mixed-valence POV, contrasting with the well-known, less toxic decavanadate. These results document the toxicity of this mixed-valence POV, which may not be suitable for biomedical applications.

V4 C3 MXene Immune Profiling and Modulation of T Cell-Dendritic Cell Function and Interaction

Although vanadium-based metallodrugs are recently explored for their effective anti-inflammatory activity, they frequently cause undesired side effects. Among 2D nanomaterials, transition metal carbides (MXenes) have received substantial attention for their promise as biomedical platforms. It is hypothesized that vanadium immune properties can be extended to MXene compounds. Therefore, vanadium carbide MXene (V4 C3 ) is synthetized, evaluating its biocompatibility and intrinsic immunomodulatory effects. By combining multiple experimental approaches in vitro and ex vivo on human primary immune cells, MXene effects on hemolysis, apoptosis, necrosis, activation, and cytokine production are investigated. Furthermore, V4 C3 ability is demonstrated to inhibit T cell-dendritic cell interactions, evaluating the modulation of CD40-CD40 ligand interaction, two key costimulatory molecules for immune activation. The material biocompatibility at the single-cell level on 17 human immune cell subpopulations by single-cell mass cytometry is confirmed. Finally, the molecular mechanism underlying V4 C3 immune modulation is explored, demonstrating a MXene-mediated downregulation of antigen presentation-associated genes in primary human immune cells. The findings set the basis for further V4 C3 investigation and application as a negative modulator of the immune response in inflammatory and autoimmune diseases.

The Deficits of Insulin Signal in Alzheimer's Disease and the Mechanisms of Vanadium Compounds in Curing AD

Vanadium is a well-known essential trace element, which usually exists in oxidation states in the form of a vanadate cation intracellularly. The pharmacological study of vanadium began with the discovery of its unexpected inhibitory effect on ATPase. Thereafter, its protective effects on β cells and its ability in glucose metabolism regulation were observed from the vanadium compound, leading to the application of vanadium compounds in clinical trials for curing diabetes. Alzheimer's disease (AD) is the most common dementia disease in elderly people. However, there are still no efficient agents for treating AD safely to date. This is mainly because of the complexity of the pathology, which is characterized by senile plaques composed of the amyloid-beta (Aβ) protein in the parenchyma of the brain and the neurofibrillary tangles (NFTs), which are derived from the hyperphosphorylated tau protein in the neurocyte, along with mitochondrial damage, and eventually the central nervous system (CNS) atrophy. AD was also illustrated as type-3 diabetes because of the observations of insulin deficiency and the high level of glucose in cerebrospinal fluid (CSF), as well as the impaired insulin signaling in the brain. In this review, we summarize the advances in applicating the vanadium compound to AD treatment in experimental research and point out the limitations of the current study using vanadium compounds in AD treatment. We hope this will help future studies in this field.

The role of heavy metals in the development of colorectal cancer

OBJECTIVE

To investigate the relationship among 18 heavy metals, microsatellite instability (MSI) status, ERCC1, XRCC1 (rs25487), BRAF V600E and 5 tumor markers and their role in the development of colorectal cancer (CRC).

METHODS

A total of 101 CRC patients and 60 healthy controls were recruited in the present study. The levels of 18 heavy metals were measured by ICP-MS. MSI status and the genetic polymorphism were determined by PCR (FP205-02, Tiangen Biochemical Technology Co., Ltd., Beijing, China) and Sanger sequencing. Spearman's rank correlation was used to analyze the relationship among various factors.

RESULTS

The level of selenium (Se) was lower in the CRC group compared with the control group (p < 0.01), while vanadium (V), arsenic (As), tin (Sn), barium (Ba) and lead (Pb) were higher (p < 0.05), chromium (Cr) and copper (Cu) were significantly higher (p < 0.0001) in the CRC group than those in the control group. Multivariate logistic regression analysis indicated that Cr, Cu, As and Ba were the risk factors for CRC. In addition, CRC was positively correlated with V, Cr, Cu, As, Sn, Ba and Pb, but negatively correlated with Se. MSI was positively correlated with BRAF V600E, but negatively correlated with ERCC1. BRAF V600E was positively correlated with antimony (Sb), thallium (Tl), CA19-9, NSE, AFP and CK19. XRCC1 (rs25487) was found to be positively correlated with Se but negatively correlated with Co. The levels of Sb and Tl were significantly higher in the BRAF V600E positive group compared to the negative group. The mRNA expression level of ERCC1 was significantly higher (P = 0.035) in MSS compared to MSI. And there was a significant correlation between XRCC1 (rs25487) polymorphism and MSI status (P<0.05).

CONCLUSION

The results showed that low level of Se and high levels of V, As, Sn, Ba, Pb, Cr, and Cu increased the risk of CRC. Sb and Tl may cause BRAF V600E mutations, leading to MSI. XRCC1 (rs25487) was positively correlated with Se but negatively correlated with Co. The expression of ERCC1 may be related to MSS, while the XRCC1 (rs25487) polymorphism is related to MSI.

Metals and Metal Complexes in Diseases with a Focus on COVID-19: Facts and Opinions

In the present Special Issue on "Metals and Metal Complexes in Diseases with a Focus on COVID-19: Facts and Opinions", an attempt has been made to include reports updating our knowledge of elements considered to be potential candidates for therapeutic applications and certain metal-containing species, which are extensively being examined towards their potential biomedical use due to their specific physicochemical properties [...].

Oxidative potential of metal-polluted urban dust as a potential environmental stressor for chronic diseases

Oxidative stress (OS) associated with metals in urban dust has become a public health concern. Chronic diseases linked to general inflammation are particularly affected by OS. This research analyzes the spatial distribution of metals associated with OS, the urban dust´s oxidative potential (OP), and the occurrence of diseases whose treatments are affected by OS. We collected 70 urban dust samples during pre- and post-monsoon seasons to achieve this. We analyzed particle size distribution and morphology by scanning electron microscopy, as well as metal(loid)s by portable X-ray fluorescence, and OP of dust in artificial lysosomal fluid by using an ascorbic acid depletion assay. Our results show that the mean concentration of Fe, Pb, As, Cr, Cu, and V in pre-monsoon was 83,984.6, 98.4, 23.5, 165.8, 301.3, and 141.9 mg kg^-1, while during post-monsoon was 50,638.8, 73.9, 16.7, 124.3, 178.9, and 133.5 mg kg^-1, respectively. Impoverished areas with the highest presence of cardiovascular, cancer, diabetes, and respiratory diseases coincide with contaminated areas where young adults live. We identified significant differences in the OP between seasons. OP increases during the pre-monsoon (from 7.8 to 237.5 nmol AA min^-1) compared to the post-monsoon season (from 1.6 to 163.2 nmol AA min^-1). OP values are much higher than measured standards corresponding to contaminated soil and urban particulate matter, which means that additional sources beside metals cause the elevated OP. The results show no risk from chronic exposure to metals; however, our results highlight the importance of studying dust as an environmental factor that may potentially increase oxidative stress.

Biodistribution of Vanadium Dioxide Particles in Mice by Consecutive Gavage Administration: Effects of Particle Size, Dosage, and Health Condition of Mice

The newly developed vanadium dioxide (VO₂), a material with excellent reversible and multi-stimuli responsible phase transition property, has been widely used in high-performance and energy-saving smart devices. The rapid growth of the VO₂-based emerging technologies and the complex biological effect of vanadium to organisms urge a better understanding of the behavior of VO₂ in vivo for safety purpose. Herein, we study the absorption, distribution, and excretion of two commercial VO₂ (nanoscale SVO₂ and bulk MVO₂) in mice after consecutive gavage administration for up to 28 days. The absorption of both types of VO₂ is as low as less than 1.5% of the injected dose within 28 days, while MVO₂ is several times more difficult to be absorbed than SVO₂. Almost all unabsorbed VO₂ is excreted through feces. For the absorbed vanadium, bone is the organ with the largest accumulation, followed by liver, kidney, and spleen. The vanadium content in organs shows a size-, dosage-, and animal health condition-dependent manner, and increases gradually to a saturation value along with the consecutive administration. Generally, smaller particle size and higher dosage lead to higher vanadium contents in organs, and more vanadium accumulates in bone and liver in diabetic mice than in normal mice. After the treatment is stopped, the accumulated vanadium in organs decreases a lot within 14 days, even reaches to the background level in some organs, but the content of vanadium in the bone remains high after 14 days post-exposure. These findings provide basic information for the safety assessment and safe applications of VO₂-based materials.

Comparison of the Effects on Bovine Serum Albumin Induced by Different Forms of Vanadium

Various forms of vanadium coexist in vivo, and the behavior mechanism is different. An investigation of the separate and simultaneous binding of three vanadium forms with bovine serum albumin (BSA) was performed. VO(acac)₂/NaVO₃/VOSO₄ bound to site I of BSA, and their binding constants were 4.26 × 10⁵, 9.18 × 10³, and 4.31 × 10² L mol^-1 at 298 K, respectively. VO(acac)₂ had the strongest binding ability to BSA and had the most influence on the secondary structure of BSA and the microenvironment of around amino acid residues. The effect of NaVO₃ and VOSO₄ coexistence on the binding of VO(acac)₂ to BSA was therefore further investigated. Both NaVO₃ and VOSO₄ had an effect on the binding of VO(acac)₂ and BSA, with NaVO₃ having the most noticeable effect. NaVO₃ interfered with the binding process of VO(acac)₂ and BSA, increased the binding constant, and changed the binding forces between them. Competition and allosteric effect may be responsible for the change of binding process between VO(acac)₂ and BSA in the presence of NaVO₃/VOSO₄.

The Biological Applications of Metals and Metal Complexes

Over the course of biological evolution, approximately 25 to 30 elements have been recognized as essential for the proper functioning of biological systems since the emergence of life [...]

CNS-Related Effects Caused by Vanadium at Realistic Exposure Levels in Humans: A Comprehensive Overview Supplemented with Selected Animal Studies

Neurodegenerative disorders, which are currently incurable diseases of the nervous system, are a constantly growing social concern. They are progressive and lead to gradual degeneration and/or death of nerve cells, resulting in cognitive deterioration or impaired motor functions. New therapies that would ensure better treatment results and contribute to a significant slowdown in the progression of neurodegenerative syndromes are constantly being sought. Vanadium (V), which is an element with a wide range of impacts on the mammalian organism, is at the forefront among the different metals studied for their potential therapeutic use. On the other hand, it is a well-known environmental and occupational pollutant and can exert adverse effects on human health. As a strong pro-oxidant, it can generate oxidative stress involved in neurodegeneration. Although the detrimental effects of vanadium on the CNS are relatively well recognized, the role of this metal in the pathophysiology of various neurological disorders, at realistic exposure levels in humans, is not yet well characterized. Hence, the main goal of this review is to summarize data on the neurological side effects/neurobehavioral alterations in humans, in relation to vanadium exposure, with the focus on the levels of this metal in biological fluids/brain tissues of subjects with some neurodegenerative syndromes. Data collected in the present review indicate that vanadium cannot be excluded as a factor playing a pivotal role in the etiopathogenesis of neurodegenerative illnesses, and point to the need for additional extensive epidemiological studies that will provide more evidence supporting the relationship between vanadium exposure and neurodegeneration in humans. Simultaneously, the reviewed data, clearly showing the environmental impact of vanadium on health, suggest that more attention should be paid to chronic diseases related to vanadium and to the assessment of the dose-response relationship.

Association between urinary metal concentrations and abnormal estimated glomerular filtration rate in Chinese community-dwelling elderly: Exploring the mediating effect of triglycerides

BACKGROUND

Environmental metal exposure is associated with elevated triglycerides (TG) and the development of chronic kidney disease (CKD). However, the relationship between metal exposure and glomerular filtration rate (GFR) remains uncertain, and the mediating effect of TG between the two is unclear.

METHODS

This study measured the concentrations of 14 metals in urine samples from 3752 elderly people in the community. The most relevant metals were screened by least absolute shrinkage and selection operator (LASSO) regression. The relationship between combined exposure to multiple metals and abnormal estimated glomerular filtration rate (eGFR) was explored using multivariate logistic regression analysis and Bayesian kernel machine regression (BKMR) analysis. Generalized linear regression models and the Karlson-Holm-Green (KHB) method were used to assess the mediating effects of TG.

RESULTS

In the single-metal model, calcium (Ca), iron (Fe), selenium (Se), strontium (Sr), and thallium (Tl) showed significant negative correlations with the prevalence of abnormal eGFR (all P < 0.05). In the multi-metals model, Ca, Se, and Tl continued to show significant negative correlations, while vanadium (V) and zinc (Zn) showed significant positive correlations with abnormal eGFR (all P < 0.05). The BKMR model showed a negative joint effect of the mixture of Ca, V, Zn, Se, and Tl on the prevalence of abnormal eGFR. The generalized linear regression model showed a significant positive correlation between the concentrations of Ca (β = 0.07), Zn (β = 0.07), Se (β = 0.09), and TG levels (all P < 0.05). In the mediation analysis, TG masked a 4.30% and 5.21% correlation between Ca and Se and the prevalence of eGFR abnormalities, respectively.

CONCLUSIONS

Urinary concentration of multiple metals is significantly associated with eGFR abnormalities, and Ca, and Se may be among the potential protective factors. TG masked some of the protective effects of Ca and Se.

Enhanced selective separation of vanadium(V) and chromium(VI) using the CeO2 nanorod containing oxygen vacancies

Adsorption of vanadium from wastewater defends the environment from toxic ions and contributes to recover the valuable metal. However, it is still challenging for the separation of vanadium (V⁵⁺) and chromium (Cr⁶⁺) because of their similar properties. Herein, a kind of CeO₂ nanorod containing oxygen vacancies is facilely synthesized which displays ultra-high selectivity of V⁵⁺ against various competitive ions (i.e., Fe, Mn, Cr, Ni, Cu, Zn, Ga, Cd, Ba, Pb, Mg, Be, and Co). Moreover, a large separation factor (SF_V/Cr) of 114,169.14 for the selectivity of V⁵⁺ is achieved at the Cr⁶⁺/V⁵⁺ ratio of 80 with the trace amount of V⁵⁺ (~ 1 mg/L). The results show that the process of V⁵⁺ uptake is the monolayer homogeneous adsorption and is controlled by external and intraparticle diffusions. In addition, it also shows that V⁵⁺ is reduced to V³⁺ and V⁴⁺ and then formation of V-O complexation. This work offers a novel CeO₂ nanorod material for efficient separation of V⁵⁺ and Cr⁶⁺ and also clarifies the mechanism of the V⁵⁺ adsorption on the CeO₂ surface.