Vanadium in the detection, prevention and treatment of cancer: the in vivo evidence

Evaluation of pollution levels in sediments from Lake Edku, Egypt using laser ablation inductively coupled plasma mass spectrometry

The concentrations of 11 heavy metals in sediments from Lake Edku, Egypt were determined using LA-ICP-MS. The average concentrations of elements occurred in the order of Fe > V > Cr > Zn > Ni > Cu > Co > Pb > As > Sn > Mo with respective values of 4.67 %, 104.8, 77.9, 76.6, 59.2, 52, 27.8, 19.8, 4.14, 2.24, and 1.45 μg/g. Several pollution indices were used to evaluate individual and cumulative contamination levels. All HMs were found to be in the deficiency to minimal enrichment range based on the enrichment factor. The contamination factor indicated low contamination levels of Cr and As, low to moderate contamination levels of Fe, Ni, Zn, Mo, Sn, and Pb, and moderate contamination levels of Co and Cu. The pollution load index and contamination degree indicated the sediments to be polluted and moderately polluted, respectively.

Molecular modeling of [VO(L1-4)(R)] complexes (R = bipyridine, phenanthroline): DFT study of antioxidant activity, DNA binding and evaluation of electron-donating and -withdrawing substituent groups

A DFT (density functional theory) study was conducted with eight oxovanadium complexes (C1 - C8) of general formula [VO(L1-4)(R)] (R = bipyridine, phenanthroline; L1-4 = group of ligands derived from dithiocarbamate). The obtained geometries showed a good correlation with the experimental structures. Molecular orbital analysis revealed that the contribution of the L-ligand in the SOMO (single-occupied molecular orbital) of the complexes correlated with the experimental antioxidant activity (IC50), while the contribution of the R-ligand to the LUMO (lowest unoccupied molecular orbital) of the complexes correlated with the experimental complex-DNA interaction (Kb). It has been identified that the presence of an electron-donating substituent group (such as -NH2) in the C5 - C6 structures should enhance these complexes' antioxidant and DNA interaction activities.

Substitution Kinetics, Albumin and Transferrin Affinities, and Hypoxia All Affect the Biological Activities of Anticancer Vanadium(V) Complexes

Limited stability of most transition-metal complexes in biological media has hampered their medicinal applications but also created a potential for novel cancer treatments, such as intratumoral injections of cytotoxic but short-lived anticancer drugs. Two related V(V) complexes, [VO(Hshed)(dtb)] (1) and [VO(Hshed)(cat)] (2), where H2shed = N-(salicylideneaminato)-N'-(2-hydroxyethyl)-1,2-ethanediamine, H2dtb = 3,5-di-tert-butylcatechol, and H2cat = 1,2-catechol, decomposed within minutes in cell culture medium at 310 K (t1/2 = 43 and 9 s for 1 and 2, respectively). Despite this, both complexes showed high antiproliferative activities in triple-negative human breast cancer (MDA-MB-231) cells, but the mechanisms of their activities were radically different. Complex 1 formed noncovalent adducts with human serum albumin, rapidly entered cells via passive diffusion, and was nearly as active in a short-term treatment (IC50 = 1.9 ± 0.2 μM at 30 min) compared with a long-term treatment (IC50 = 1.3 ± 0.2 μM at 72 h). The activity of 1 decreased about 20-fold after its decomposition in cell culture medium for 30 min at 310 K. Complex 2 showed similar activities (IC50 ≈ 12 μM at 72 h) in both fresh and decomposed solutions and was inactive in a short-term treatment. The activity of 2 was mainly due to the reactions among V(V) decomposition products, free catechol, and O2 in cell culture medium. As a result, the activity of 1 was less sensitive than that of 2 to the effects of hypoxic conditions that are characteristic of solid tumors and to the presence of apo-transferrin that acts as a scavenger of V(V/IV) decomposition products in blood serum. In summary, complex 1, but not 2, is a suitable candidate for further development as an anticancer drug delivered via intratumoral injections. These results demonstrate the importance of fine-tuning the ligand properties for the optimization of biological activities of metal complexes.

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.

Medicinal applications of vanadium complexes with Schiff bases

Many transition metal complexes have been explored for their therapeutic properties after the discovery of cisplatin. Schiff bases have an efficient complexation tendency with the transition metals and several medicinal properties have been reported. However, fewer studies have reported the medicinal utility of vanadium and its Schiff base complexes. This paper provides a comprehensive overview of vanadium complexes with Schiff bases along with their mechanistic insight. Vanadium complexes in + 4 and + 5 oxidation states have exhibited well-defined geometry and found to be thermodynamically stable. The studies have reported the G0/G1 phase cell cycle arrest and decreased delta psi m, inducing mitochondrial membrane depolarization in cancer cell lines along with the alterations in the metabolism of the cancer cells upon dosing with the vanadium complexes. Cancer cell invasion and growth are also found to be markedly reduced by peroxo complexes of vanadium. The studies included in the review paper have been taken from leading indexing databases and focus was laid on recent reports in literature. The biological potential of vanadium complexes of Schiff bases opens new horizons for future interdisciplinary studies and investigation focussed on understanding the biochemistry of these complexes, along with designing new complexes which have better bioavailability, solubility and low or non-toxicity.

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.

DNA fragmentation and multifaceted toxicity induced by high-dose vanadium exposure determined by the bioindicator Allium test

In this study, the toxicity of vanadium (VCI₃) in Allium cepa L. was studied. Germination-related parameters, mitotic index (MI), catalase (CAT) activity, chromosomal abnormalities (CAs), malondialdehyde (MDA) level, micronucleus (MN) frequency and superoxide dismutase (SOD) activity were investigated. The effects of VCI₃ exposure on the DNA of meristem cells were investigated with the help of comet assay, and the relationships between physiological, cytogenetic and biochemical parameters were revealed by correlation and PCA analyses. A. cepa bulbs were germinated with different concentrations of VCI₃ for 72 h. As a result, the maximum germination (100%), root elongation (10.4 cm) and weight gain (6.85 g) were determined in the control. VCI₃ treatment caused significant decreases in all tested germination-related parameters compared to the control. The highest percentage of MI (8.62%) was also observed in the control. No CAs were found in the control, except for a few sticky chromosomes and unequal distribution of chromatin (p > 0.05). VCI₃ treatment caused significant decreases in MI and increases in the frequencies of CAs and MN, depending on the dose. Similarly, the comet assay showed that DNA damage scores increased with increasing VCI₃ doses. The lowest root MDA (6.50 µM/g) level and SOD (36.7 U/mg) and CAT (0.82 OD_240nmmin/g) activities were also measured in the control. VCI₃ treatment caused significant increases in root MDA levels and antioxidant enzyme activities. Besides, VCI₃ treatment induced anatomical damages such as flattened cell nucleus, epidermis cell damage, binuclear cell, thickening in the cortex cell wall, giant cell nucleus, damages in cortex cell and unclear vascular tissue. All examined parameters showed significant negative or positive correlations with each other. PCA analysis confirmed the relations of investigated parameters and VCI₃ exposure.

Soil covering measure mitigates vanadium loss during short-term simulated rainfall in the vanadium titano-magnetite tailings reservoir

Soil covering is an operative measure to decline pollutant release in tailings reservoirs and promote vegetation restoration, yet urgent research still needs to probe into pollutant leaching and migration in the artifact technology under extreme precipitation. Here, a soil column leaching experiment was designed to explore the migration and behaviors of vanadium (V) in the system of vanadium titano-magnetite tailings (VTMTs) covered by soils with different depths (5 cm, 10 cm, and 15 cm). Chemical fractions of V in the VTMTs and covered soils were analyzed to decipher the mechanisms underlying the V migration. We found a limited V leaching (0.26-0.52 μg/L, <0.01% of total V) in the columns during the experiments, and V in the VTMTs was not apt to be leached or migrate upward to the overlying soils. The soil volumes overlaid had nonsignificant effect on the V behaviors in the VTMTs (P > 0.05), because of the dominant and stable residual V (96.4% of total V) in the tailings. Although acid soluble V might be transformed to oxidizable V, it was resupplied by the fractions of weak-bound V in the solid phases during the leaching experiments. The mineral metal (hydr)oxides (e.g., aluminum, iron) determined the V behaviors in the VTMTs via absorption effect, and the high affinity of V to organic matters probably prevented its migration throughout the overlying soils. The results indicate that soil covering measure in the VTMTs reservoirs effectively reduces V migration or release from the tailings through leaching or upward migration, which provides a significant guidance for vegetation restoration in V-rich tailings reservoirs.

Systemic Essential Metal and Metalloid Levels in Patients with Benign Breast Disease and Breast Cancer

The objective of the present study is evaluation of serum and hair levels of essential metals and metalloids in women with benign breast disease and breast cancer in order to define similar and distinct patterns that may mediate the link between these pathologies. A total of 310 adult women aged 20-80 years old were enrolled in the present study. Of those, 103 patients had benign (fibrocystic) breast disease, 107 patients had breast cancer (stage II), and 100 women were healthy and with absence of breast pathology. Trace metal and metalloid levels in hair and serum were evaluated by inductively coupled argon plasma mass-spectrometry (ICP-MS). The data demonstrate that breast cancer patients were characterized by significantly higher hair Cr and V levels, as well as reduced Cu and Mn content as compared to both benign breast disease patients and controls. In contrast, serum Cu levels in women with breast cancer exceeded those in the controls and benign breast disease cases. Patients with both benign and malignant breast tumors were characterized by lower serum Mn levels as compared to the control values. Serum Cu/Zn and especially Cu/Mn were found to be significantly increased in cancer patients. Significantly reduced hair and serum Se levels were noted only in women with fibrocystic disease. Based on the analysis of two biosamples, it is proposed that malignant breast tumor development is associated with the reduction of systemic Mn and Zn levels, and a concomitant elevation of Cu concentrations.

Vanadium in Bipolar Disorders-Reviving an Old Hypothesis

Bipolar disorder (BD) is a severe and common chronic mental illness. The biological basis of the disease is poorly understood and its treatment is unsatisfactory. Our previous studies supported the notion that alterations in Na⁺, K⁺-ATPase activity were involved in the etiology of BD. As various chemical elements inhibit Na⁺, K⁺-ATPase, we determined the concentration of 26 elements in the serum of BD patients before and after treatment and in postmortem brain samples from BD patients, and compared them with matched controls. The only element that was reduced significantly in the serum following treatment was vanadium (V). Furthermore, the concentration of V was significantly lower in the pre-frontal cortex of BD patients compared with that of the controls. Intracerebroventricular administration of V in mice elicited anxiolytic and depressive activities, concomitantly inhibited brain Na⁺, K⁺-ATPase activity, and increased extracellular signal-regulated kinase phosphorylation. A hypothesis associating V with BD was set forth decades ago but eventually faded out. Our results are in accord with the hypothesis and advocate for a thorough examination of the possible involvement of chemical elements, V in particular, in BD.

Impact of Environmental Risk Factors on Mitochondrial Dysfunction, Neuroinflammation, Protein Misfolding, and Oxidative Stress in the Etiopathogenesis of Parkinson's Disease

As a prevalent progressive neurodegenerative disorder, Parkinson's disease (PD) is characterized by the neuropathological hallmark of the loss of nigrostriatal dopaminergic (DAergic) innervation and the appearance of Lewy bodies with aggregated α-synuclein. Although several familial forms of PD have been reported to be associated with several gene variants, most cases in nature are sporadic, triggered by a complex interplay of genetic and environmental risk factors. Numerous epidemiological studies during the past two decades have shown positive associations between PD and several environmental factors, including exposure to neurotoxic pesticides/herbicides and heavy metals as well as traumatic brain injury. Other environmental factors that have been implicated as potential risk factors for PD include industrial chemicals, wood pulp mills, farming, well-water consumption, and rural residence. In this review, we summarize the environmental toxicology of PD with the focus on the elaboration of chemical toxicity and the underlying pathogenic mechanisms associated with exposure to several neurotoxic chemicals, specifically 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), rotenone, paraquat (PQ), dichloro-diphenyl-trichloroethane (DDT), dieldrin, manganese (Mn), and vanadium (V). Our overview of the current findings from cellular, animal, and human studies of PD provides information for possible intervention strategies aimed at halting the initiation and exacerbation of environmentally linked PD.

Relationship between structure and cytotoxicity of vanadium and molybdenum complexes with pyridoxal derived ligands

In this work four vanadium complexes (compounds 1, 2, 3 and 4) and one molybdenum complex (compound 5) with hydrazone ligands derived from pyridoxal were synthesized and characterized. All compounds are mononuclear species, two of them (compounds 3 and 5) are dioxide complexes and the other three (compounds 1, 2 and 4) monoxide complexes. The vanadium atom of the compound 3 is five-coordinated and all the other compounds have a six coordinated environment polyhedron. The poses for the potential intercalation of the compounds 2 and 3 with DNA were obtained by using AutoDock software. Optimizations were also performed at PM6-D3H4 semi-empirical level whereas the study of the nature of the interaction was carried out by means of the Energy Decomposition Analysis and the Non-Covalent Interaction index by using in both cases Density Functional Theory computations. The cytotoxicity in lung cancer cells (A549 cell line) of all the compounds was also evaluated. After 24 h of treatment, vanadium complexes showed high values of IC₅₀, between 419.93 ± 22.58 and 685.88 ± 46.55 μM. After 48 h, the results showed that the compound 3 had the lowest IC₅₀ value, 65.32 ± 9.95 μM, and the compound 2 the highest value, 375.28 ± 32.09 μM. The molybdenum complex showed the lowest IC₅₀ value at 48 h (11.22 ± 1.34 μM). The toxicity of the compounds 3, 4 and 5 was tested in vivo, using zebrafish model, and the molybdenum complex showed higher toxic effects than the studied vanadium complexes.

Dependency of EGFR activation in vanadium-based sensitization to oncolytic virotherapy

Oncolytic virotherapy is a clinically validated approach to treat cancers such as melanoma; however, tumor resistance to virus makes its efficacy variable. Compounds such as sodium orthovanadate (vanadate) can overcome viral resistance and synergize with RNA-based oncolytic viruses. In this study, we explored the basis of vanadate mode of action and identified key cellular components in vanadate’s oncolytic virus-enhancing mechanism using a high-throughput kinase inhibitor screen. We found that several kinase inhibitors affecting signaling downstream of the epidermal growth factor receptor (EGFR) pathway abrogated the oncolytic virus-enhancing effects of vanadate. EGFR pathway inhibitors such as gefitinib negated vanadate-associated changes in the phosphorylation and localization of STAT1/2 as well as NF-κB signaling. Moreover, gefitinib treatment could abrogate the viral sensitizing response of vanadium compounds in vivo. Together, we demonstrate that EGFR signaling plays an integral role in vanadium viral sensitization and that pharmacological EGFR blockade can counteract vanadium/oncolytic virus combination therapy.

Harnessing oxidative stress for anti-glioma therapy

Glioma cells use intermediate levels of reactive oxygen species (ROS) and reactive nitrogen species (RNS) for growth and invasion, and suppressing these reactive molecules thus may compromise processes that are vital for glioma survival. Increased oxidative stress has been identified in glioma cells, in particular in glioma stem-like cells. Studies have shown that these cells harbor potent antioxidant defenses, although endogenous protection against nitrosative stress remains understudied. The enhancement of oxidative or nitrosative stress offers a potential target for triggering glioma cell death, but whether oxidative and nitrosative stresses can be combined for therapeutic effects requires further research. The optimal approach of harnessing oxidative stress for anti-glioma therapy should include the induction of free radical-induced oxidative damage and the suppression of antioxidant defense mechanisms selectively in glioma cells. However, selective induction of oxidative/nitrosative stress in glioma cells remains a therapeutic challenge, and research into selective drug delivery systems is ongoing. Because of multifactorial mechanisms of glioma growth, progression, and invasion, prospective oncological therapies may include not only therapeutic oxidative/nitrosative stress but also inhibition of oncogenic kinases, antioxidant molecules, and programmed cell death mediators.

Alzheimer's Disease and Diabetes Mellitus in Comparison: The Therapeutic Efficacy of the Vanadium Compound

Alzheimer’s disease (AD) is an intractable neurodegenerative disease that leads to dementia, primarily in elderly people. The neurotoxicity of amyloid-beta (Aβ) and tau protein has been demonstrated over the last two decades. In line with these findings, several etiological hypotheses of AD have been proposed, including the amyloid cascade hypothesis, the oxidative stress hypothesis, the inflammatory hypothesis, the cholinergic hypothesis, et al. In the meantime, great efforts had been made in developing effective drugs for AD. However, the clinical efficacy of the drugs that were approved by the US Food and Drug Association (FDA) to date were determined only mild/moderate. We recently adopted a vanadium compound bis(ethylmaltolato)-oxidovanadium (IV) (BEOV), which was originally used for curing diabetes mellitus (DM), to treat AD in a mouse model. It was shown that BEOV effectively reduced the Aβ level, ameliorated the inflammation in brains of the AD mice, and improved the spatial learning and memory activities of the AD mice. These finding encouraged us to further examine the mechanisms underlying the therapeutic effects of BEOV in AD. In this review, we summarized the achievement of vanadium compounds in medical studies and investigated the prospect of BEOV in AD and DM treatment.

Vanadium(V) Complexes with Siderophore Vitamin E-Hydroxylamino-Triazine Ligands

Novel vitamin E chelate siderophore derivatives and their VV and FeIII complexes have been synthesised and the chemical and biological properties have been evaluated. In particular, the α- and δ-tocopherol derivatives with bis-methyldroxylamino triazine (α-tocTHMA) and (δ-tocDPA) as well their VV complexes, [V2VO3(α-tocTHMA)2] and [V2IVO3(δ-tocTHMA)2], have been synthesised and characterised by infrared (IR), nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR) and ultra violet-visible (UV-Vis) spectroscopies. The dimeric vanadium complexes in solution are in equilibrium with their respefrctive monomers, H2O + [V2VO2(μ-O)]4+ = 2 [VVO(OH)]2+. The two amphiphilic vanadium complexes exhibit enhanced hydrolytic stability. EPR shows that the complexes in lipophilic matrix are mild radical initiators. Evaluation of their biological activity shows that the compounds do not exhibit any significant cytotoxicity to cells.

Albumin-EDTA-Vanadium Is a Powerful Anti-Proliferative Agent, Following Entrance into Glioma Cells via Caveolae-Mediated Endocytosis

Human serum albumin (HSA) is efficiently taken up by cancer cells as a source of carbon and energy. In this study, we prepared a monomodified derivative of HSA covalently linked to an EDTA derivative and investigated its efficacy to shuttle weakly anti-proliferative EDTA associating ligands such as vanadium, into a cancer cell line. HSA-S-MAL-(CH₂)₂-NH-CO-EDTA was found to associate both with the vanadium anion (+5) and the vanadium cation (+4) with more than thrice the associating affinity of those ligands toward EDTA. Both conjugates internalized into glioma tumor cell line via caveolae-mediated endocytosis pathway and showed potent anti-proliferative capacities. IC₅₀ values were in the range of 0.2 to 0.3 µM, potentiating the anti-proliferative efficacies of vanadium (+4) and vanadium (+5) twenty to thirty fold, respectively. HSA-EDTA-VO⁺⁺ in particular is a cancer permeable prodrug conjugate. The associated vanadium (+4) is not released, nor is it active anti-proliferatively prior to its engagement with the cancerous cells. The bound vanadium (+4) dissociates from the conjugate under acidic conditions with half maximal value at pH 5.8. In conclusion, the anti-proliferative activity feature of vanadium can be amplified and directed toward a cancer cell line. This is accomplished using a specially designed HSA-EDTA-shuttling vehicle, enabling vanadium to be anti-proliferatively active at the low micromolar range of concentration.

Protein binding and cytotoxic activities of monomeric and dimeric oxido-vanadium(V) salan complexes: Exploring the solution behavior of monoalkoxido-bound oxido-vanadium(V) complex

Three ONNO donor tetradentate diamino bis(phenolato) "salan" ligands, N, N'-dimethyl-N, N'-bis-(5-chloro-2-hydroxy-3-methyl-benzyl)-1,2-diaminoethane (H₂L¹), N, N'-dimethyl-N, N'-bis-(5-chloro-2-hydroxy-3-isopropyl-6-methyl-benzyl)-1,2-diamino-ethane (H₂L²) and N, N'-bis-(5-chloro-2-hydroxy-3-isopropyl-6-methyl-benzyl)-1,2-diaminocyclohexane (H₂L³) have been synthesized by following Mannich condensation reaction. Reaction of these ligands with their corresponding vanadium metal precursors gave one oxidomethoxidovanadium(V) [V^VOL¹(OCH₃)] (1) and two monooxido-bridged divanadium (V, V) complexes [V^VOL^2-3]₂(μ-O) (2-3). The complexes were characterized by IR, UV-vis, NMR and ESI mass spectrometry. Also, the structure of all the complexes (1-3) was confirmed by the Single-Crystal X-ray diffraction analysis, which revealed a distorted octahedral geometry around the metal centres. The solution behavior of the [V^VOL¹(OCH₃)] (1) reveals the formation of two different types of V(V) species in solution, the structurally characterized compound 1 and its corresponding monooxido-bridged divanadium (V, V) complex [V^VOL¹]₂(μ-O), which was further studied by IR, and NMR spectroscopy. The electrochemical behavior of all the complexes was evaluated through cyclic voltammetry. Interaction of the salan-V(V) complexes with human serum albumin (HSA) and bovine serum albumin (BSA) were analysed through fluorescence quenching, UV-vis absorption titration, synchronous fluorescence, circular dichroism studies, and förster resonance energy transfer (FRET). Finally, the in vitro cytotoxicity of the complexes was investigated against MCF-7 and HT-29 and NIH-3T3 cell lines. Cytotoxicity value of complexes in both MCF-7 and HT-29 follows the same trend that is 3 > 1 > 2 which is in line with protein binding affinity of the complexes.

Study of DNA Interaction and Cytotoxicity Activity of Oxidovanadium(V) Complexes with ONO Donor Schiff Base Ligands

Two new oxidovanadium(V) complexes, (HNEt3)[VVO2L] (1) and [(VVOL)2μ-O] (2), have been synthesized using a tridentate Schiff base ligand H2L [where H2L = 4-((E)-(2-hydroxy-5-nitrophenylimino)methyl)benzene-1,3-diol] and VO(acac)2 as starting metal precursor. The ligand and corresponding metal complexes are characterized by physicochemical (elemental analysis), spectroscopic (FT-IR, UV–Vis, and NMR), and spectrometric (ESI–MS) methods. X-ray crystallographic analysis indicates the anion in salt 1 features a distorted square-pyramidal geometry for the vanadium(V) center defined by imine-N, two phenoxide-O, and two oxido-O atoms. The interaction of the compounds with CT–DNA was studied through UV–Vis absorption titration and circular dichroism methods. The results indicated that complexes showed enhanced binding affinity towards DNA compared to the ligand molecule. Finally, the in vitro cytotoxicity studies of H2L, 1, and 2 were evaluated against colon cancer (HT-29) and mouse embryonic fibroblast (NIH-3T3) cell lines by MTT assay. The results demonstrated that the compounds manifested a cytotoxic potential comparable with clinically referred drugs and caused cell death by apoptosis.

Bis(ethylmaltolato)oxidovanadium (IV) attenuates amyloid-beta-mediated neuroinflammation by inhibiting NF-κB signaling pathway via a PPARγ-dependent mechanism

Neuroinflammation plays a pivotal role in the pathophysiology of neurodegenerative diseases, such as Parkinson's disease and Alzheimer's disease. During brain neuroinflammation, activated microglial cells resulting from amyloid-beta (Aβ) overload trigger toxic proinflammatory responses. Bis(ethylmaltolato)oxidovanadium (BEOV) (IV), an important vanadium compound, has been reported to have anti-diabetic, anti-cancer, and neuroprotective effects, but its anti-inflammatory property has rarely been investigated. In the present study, the inhibitory effects of BEOV on neuroinflammation were revealed in both Aβ-stimulated BV2 microglial cell line and APPswe/PS1E9 transgenic mouse brain. BEOV administration significantly decreased the levels of tumor necrosis factor-α, interleukin-6, interleukin-1β, inducible nitric oxide synthase, and cyclooxygenase-2 both in the hippocampus of APPswe/PS1E9 mice and in the Aβ-stimulated BV2 microglia. Furthermore, BEOV suppressed the Aβ-induced activation of nuclear factor-κB (NF-κB) signaling and upregulated the protein expression level of peroxisome proliferator-activated receptor gamma (PPARγ) in a dose-dependent manner. PPARγ inhibitor GW9662 could eliminate the effect of BEOV on Aβ-induced NF-κB activation and proinflammatory mediator production. Taken altogether, these findings suggested that BEOV ameliorates Aβ-stimulated neuroinflammation by inhibiting NF-κB signaling pathway through a PPARγ-dependent mechanism.

A Dual Role of Vanadium in Environmental Systems-Beneficial and Detrimental Effects on Terrestrial Plants and Humans

The importance of vanadium (V) in the functioning of land systems is extremely diverse, as this element may exert both positive and harmful effects on terrestrial organisms. It recently become considered an element of beneficial character with a range of applications for human welfare. The health-ameliorative properties of this transition element depend on its degree of oxidation and on optimal concentration in the target cells. It was found that a similar relationship applies to vascular plants. However, excessive amounts of vanadium in the environment contaminate the soil and negatively affect the majority of living organisms. A significantly elevated level of V results in the destabilization of plant physiological balance, slowing down the growth of biomass which significantly reduces yield. In turn, low doses of the appropriate vanadium ions can stimulate plant growth and development, exert cytoprotective effects, and effectively enhance the synthesis of some biologically active compounds. We present the scientific achievements of research teams dealing with such topics. The issues discussed concern the role of vanadium in the environment, particular organisms, and highlight its dualistic influence on plants. Achievements in the field of V bioremediation, with the use of appropriately selected microorganisms and plant species, are emphasized.

Stability in solution and chemoprotection by octadecavanadates(IV/V) in E. coli cultures

Two mixed-valence octadecavanadates, (NH₄)₂(Me₄N)₅[V^IV₁₂V^V₆O₄₂I]·Me₄NI·5H₂O (V₁₈I) and [{K₆(OH₂)₁₂V^IV₁₁V^V₇O₄₁(PO₄)·4H₂O}_n] (V₁₈P), were synthesized and characterized by single-crystal X-ray diffraction analysis and FTIR, Raman, ⁵¹V NMR, EPR and UV/Vis/NIR spectroscopies. The chemoprotective activity of V₁₈I and V₁₈P towards the alkylating agent diethyl sulfate was assessed in E. coli cultures. The complex V₁₈I was nontoxic in concentrations up to 5.0 mmol L^-1, while V₁₈P presented moderate toxicity in the concentration range 0.10 - 10 mmol L^-1. Conversely, a ca. 35% enhancement in culture growth as compared to cells treated only with diethyl sulfate was observed upon addition of V₁₈I (0.10 to 2.5 mmol L^-1), while the combination of diethyl sulfate with V₁₈P increased the cytotoxicity presented by diethyl sulfate alone. ⁵¹V NMR and EPR speciation studies showed that V₁₈I is stable in solution, while V₁₈P suffers partial breakage to give low nuclearity oxidometalates of vanadium(V) and (IV). According to the results, the chemoprotective effect depends strongly on the direct reactivity of the polyoxidovanadates (POV) towards the alkylating agent. The reaction of diethyl sulfate with V₁₈I apparently produces a new, rearranged POV instead of poorly-reactive breakage products, while V₁₈P shows the formation and subsequent consumption of low-nuclearity species. The correlation of this chemistry with that of other mixed-valence polyoxidovanadates, [H₆V^IV₂V^V₁₂O₃₈PO₄]^5- (V₁₄) and [V^IV₈V^V₇O₃₆Cl]^6- (V₁₅), suggests a relationship between stability in solution and chemoprotective performance.

Selective Cytotoxicity of Complexes with N,N,N-Donor Dipodal Ligand in Tumor Cells

The present article demonstrates selective cytotoxicity against cancer cells of the complexes [Co(L^D)₂]I₂∙CH₃OH (1), [CoL^D(NCS)₂] (2) and [VOL^D(NCS)₂]∙C₆H₅CH₃ (3) containing the dipodal tridentate ligand LD = N,N-bis(3,5-dimethylpyrazol-1-ylmethyl)amine), formed in situ. All tested complexes expressed greater anticancer activities and were less toxic towards noncancerous cells than cisplatin. Cobalt complexes (1 and 2) combined high cytotoxicity with selectivity towards cancer cells and caused massive tumour cell death. The vanadium complex (3) induced apoptosis specifically in cancer cells and targeted proteins, controlling their invasive and metastatic properties. The presented experimental data and computational prediction of drug ability of coordination compounds may be helpful for designing novel and less toxic metal-based anticancer species with high specificities towards tumour cells.

Novel Oxovanadium Complex VO(hntdtsc)(NPIP): Anticancer Activity and Mechanism of Action on HeLa Cells

Oxovanadium complexes, particularly vanadyl (IV) derivatives with hybrid ligands of Schiff base and polypyridyl, have been demonstrated to possess great anticancerous therapeutic efficacy. However, most of the studies on the activity of these oxovanadium complexes have mainly focused on in vitro studies, and animal studies in vivo are extremely scarce. Based on the antitumor test results of four novel oxovanadium complexes in our previous work, this work further conducted a comprehensive antitumor activity study in vitro and in vivo on VO(hntdtsc)(NPIP), which owned the strongest inhibitory activity in vitro on multiple tumor cell proliferation. The cellular mechanism study suggested that VO(hntdtsc)(NPIP) inhibited the cell proliferation via arresting the cell cycle at G0/G1 phase through the p16-cyclin D1-CDK4-p-Rb pathway and inducing cell apoptosis through mitochondrial-dependent apoptosis pathway on HeLa cells. Inconsistent with the effects in vitro, VO(hntdtsc)(NPIP) significantly inhibited the growth of tumor and induced the apoptosis of cancer cells in mice xenograft models according to the results of nude mice in vivo image detection, H&E pathological examination, and immunohistochemical detection of p16/Ki-67 protein expression. Collectively, all the results, particularly studies in vivo, demonstrated that VO(hntdtsc)(NPIP) hold a potential to be the lead compound and further to be an anticervical cancer drug.

Vanadium pentoxide nanoparticle mediated perturbations in cellular redox balance and the paradigm of autophagy to apoptosis

The redox-active transition metals such as copper, iron, chromium, vanadium, and silica are known for its ROS generation via mechanisms such as Haber-Weiss and Fenton-type reactions. Nanoparticles of these metals induce oxidative stress due to acellular factors owing to their small size and more reactive surface area, leading to various cellular responses. The intrinsic enzyme-like activity of nano vanadium has fascinated the scientific community. However, information concerning their cellular uptake and time-dependent induced effects on their cellular organelles and biological activity is lacking. This comprehensive study focuses on understanding the precise molecular interactions of vanadium pentoxide nanoparticles (VnNp) and evaluate their specific "nano" induced effects on MDA-MB-231 cancer cells. Understanding the mechanism behind NP-induced ROS generation could help design a model for selective NP induced toxicity, useful for cancer management. The study demonstrated the intracellular persistence of VnNp and insights into its molecular interactions with various organelles and its overall effects at the cellular level. Where triple-negative breast cancer MDA-MB-231 cells resulted in 59.6% cell death towards 48 h of treatment and the normal fibroblast cells showed only 15.4% cell death, indicating an inherent anticancer property of VnNp. It acts as an initial reactive oxygen species quencher, by serving itself as an antioxidant, while; it was also found to alter the cellular antioxidant system with prolonged incubation. The VnNp accumulated explicitly in the lysosomes and mitochondria and modulated various cellular processes including impaired lysosomal function, mitochondrial damage, and autophagy. At more extended time points, VnNp influenced cell cycle arrest, inhibited cell migration, and potentiated the onset of apoptosis. Results are indicative of the fact that VnNp selectively induced breast cancer cell death and hence could be developed as a future drug molecule for breast cancer management. This could override the most crucial challenge of chemo-resistance that still remain as the main hurdle to cancer therapy.

Effects of vanadium (sodium metavanadate) and aflatoxin-B1 on cytochrome p450 activities, DNA damage and DNA methylation in human liver cell lines

Vanadium is considered as "possibly carcinogenic to humans" (V₂O₅, IARC Group 2B), yet uncertainties persist related to the toxicity mechanisms of the multiple forms of vanadium. Exposure to vanadium often co-occurs with other metals or with organic compounds that can be transformed by cytochrome p450 (CYP) enzymes into DNA-reactive carcinogens. Therefore, effects of a soluble form of vanadium (sodium metavanadate, NaVO₃) and aflatoxin-B1 (AFB1) were tested separately and together, for induction of CYP activities, DNA damage (γH2AX and DNA alkaline unwinding assays), and DNA methylation changes (global genome and DNA repeats) in HepaRG or HepG2 liver cell lines. NaVO₃ (≥ 2.3 μM) reduced CYP1A1 and CYP3A4 activities and induced DNA damage, butcaused important cell proliferation only in HepaRG cells. As a binary mixture, NaVO₃ did not modify the effects of AFB1. There was no reproducible effect of NaVO₃ (<21 μM) on DNA methylation in AluYb8, satellite-α, satellite-2, and by the luminometric methylation assay, but DNA methylation flow-cytometry signals in HepG2 cells (25-50 μM) increased at the G1 and G2 cell cycle phases. In conclusion, cell lines responded differently to NaVO₃ supporting the importance of investigating more than one cell line, and a carcinogenic role of NaVO₃ might reside at low concentrations by stimulating the proliferation of tumorigenic cells.

The liposomal delivery of hydrophobic oxidovanadium complexes imparts highly effective cytotoxicity and differentiating capacity in neuroblastoma tumour cells

Oxidovanadium complexes with organic ligands are well known to have cytotoxic or differentiating capabilities against a range of cancer cell types. Their limited use in clinical testing though has resulted largely from uncertainties about the long-term toxicities of such complexes, due in part to the speciation to vanadate ions in the circulation. We hypothesised that more highly stable complexes, delivered using liposomes, may provide improved opportunities for oxidovanadium applications against cancer. In this study we sourced specifically hydrophobic forms of oxidovanadium complexes with the explicit aim of demonstrating liposomal encapsulation, bioavailability in cultured neuroblastoma cells, and effective cytotoxic or differentiating activity. Our data show that four ethanol-solubilised complexes with amine bisphenol, aminoalcohol bisphenol or salan ligands are equally or more effective than a previously used complex bis(maltolato)oxovanadium(V) in neuroblastoma cell lines. Moreover, we show that one of these complexes can be stably incorporated into cationic liposomes where it retains very good bioavailability, apparently low speciation and enhanced efficacy compared to ethanol delivery. This study provides the first proof-of-concept that stable, hydrophobic oxidovanadium complexes retain excellent cellular activity when delivered effectively to cancer cells with nanotechnology. This offers the improved prospect of applying oxidovanadium-based drugs in vivo with increased stability and reduced off-target toxicity.

Wireless Electrochemotherapy by Selenium-Doped Piezoelectric Biomaterials to Enhance Cancer Cell Apoptosis

Cancer residues around the surgical site remain a significant cause of treatment failure with cancer recurrence. To prevent cancer recurrence and simultaneously repair surgery-caused defects, it is urgent to develop implantable biomaterials with anticancer ability and good biological activity. In this work, a functionalized implant is successfully fabricated by doping the effective anticancer element selenium (Se) into the potassium-sodium niobate piezoceramic, which realizes the wireless combination of electrotherapy and chemotherapy. Herein, we demonstrate that the Se-doped piezoelectric implant can cause mitochondrial damage by increasing intracellular reactive oxygen species levels and then trigger the caspase-3 pathway to significantly promote apoptosis of osteosarcoma cells in vitro. Meanwhile, its good biocompatibility has been verified. These results are of great importance for future deployment of wireless electro- and chemostimulation to modulate biological process around the defective tissue.

Proximal Composition of Undaria pinnatifida from San Jorge Gulf (Patagonia, Argentina)

Undaria pinnatifida is a brown macroalga considered a high quality natural food because of its numerous health benefits. The aim of this paper is to provide seasonal information on the chemical content of blades and sporophylls of U. pinnatifida from San Jorge Gulf (SJG, Chubut, Argentina) in order to evaluate their different uses. Moreover, samples of algae deposited on the beach are also studied. A multi-elemental analysis is made by Total Reflection X-ray Fluorescence (TXRF). Sixteen elements are quantified: As, Br, Ca, Cr, Cu, Fe, K, Mn, Ni, P, Pb, Rb, S, Sr, V and Zn. The results reveal that the mineral content in blades of U. pinnatifida is high, especially in autumn. Some elements show an important seasonal variation, such as: K (14-54.8 g kg-1), P (2.7-7.0 g kg-1), Sr (361-569 mg kg-1), Fe (62-140 mg kg-1), Zn (8-103 mg kg-1), Br (45-94 mg kg-1) and Rb (4-24 mg kg-1). In the case of potentially toxic elements, a variation was seen mainly in arsenic, with higher values during summer and autumn. The concentrations of nickel and lead are below the limit of detection (0.9 mg kg-1). Sporophylls contain high concentrations of macro and micronutrients, with maximum values in spring. Besides, reproductive structures showed higher total arsenic values than blades. This could indicate that arsenic is mainly accumulated in sporophylls. Algae deposited on the beach are considered a waste; but they show a similar elemental composition to the samples extracted from the sea. We concluded that all samples analyzed could be used as food or fertilizers by local populations.

Potential Medicinal Applications of Vanadium and its Coordination Compounds in Current Research Prospects: A Review

Background:

The variety of biological applications of vanadium impressed researchers to develop vanadium based drugs. The most well-known fact of vanadium is that it is necessary for human beings as an insulin-enhancing agent and herein, we mainly provide an overview of vanadium-based drugs and their applications in the medicinal field for the treatment of diseases such as diabetes and cancer. The first part of this review is focused on mechanistic studies involved in the anti-diabetic activity. The latter part explains the use of vanadium and its related coordination compounds in the treatment of cancer.

Methods:

This review is purely based on literature search available in the database. We focused on the reports available on the recent advancements in the vanadium chemistry and its biological properties, mainly anti-diabetic and anticancer activities of vanadium based compounds.

Results:

The study of clinical trials of vanadium and its drug molecules imposed more demand due to their remarkable activity with less toxicity.

Conclusion:

A brief literature survey was made pertaining to the applications of vanadium compounds/ complexes. Particularly, special attention was paid to explaining mechanistic studies of vanadium based compounds in the treatment of diabetes and cancer.

Synthesis and Experimental-Computational Characterization of a Copper/Vanadium Compound with Potential Anticancer Activity

Cancer represents a major worldwide public health problem. While significant advances in different fronts are being made to combat the disease, the development of new metal-based drugs with cytotoxic capabilities is of high relevance. This work presents a heterobimetallic molecule comprising two moieties with a structure similar to Casiopeina II-gly. One of them has a cyclotetravanadate anion that functions as an inorganic bridge coordinating two Cu (II) atoms resulting in a hexanuclear [Cu(phen)(Gly)-µ2-V4O12-Cu(phen)(Gly)]2− complex, which is counterbalanced by two isolated [Cu(phen)(Gly)(H2O)]1+ cations. Ten water molecules arranged in two sets of five-member chains also play an essential role in the 3D supramolecular structure of the compound. The molecule was designed to provide Cu and V, two metals with proven anticancer capabilities in the same molecular structure. The compound was synthesized and characterized by elemental analysis; visible, FTIR, and Raman spectroscopies; 51V Nuclear Magnetic Resonance; cyclic voltammetry; and monocrystalline X-ray diffraction. The structural, spectroscopic, and electronic properties of the compound were calculated through the density functional theory (DFT) using the Minnesota functional M06-2X and the Def2TZVP/LANL2TZ(f) basis sets with an effective core potential (ECP) for metals. Noncovalent interactions were analyzed using a natural population analysis (NPA) and Hirshfeld surfaces. The compound upon dissociation provides two metals that can interact with important biological targets in a variety of cancer cell models.

Synthesis of vitamin E and aliphatic lipid vanadium(IV) and (V) complexes, and their cytotoxic properties

Novel vitamin E chelate derivatives and their V^IV/V complexes have been synthesized and characterized, and their anticancer properties have been evaluated. The new complexes have been designed to exhibit enhanced cytotoxicity by combining high lipophilicity with the properties of vanadium to induce the formation of reactive oxygen species (ROS). In particular, the β-tocopherol derivatives with iminodiethanol (β-tocDEA) and dipicolylamine (β-tocDPA) as well their V^V and V^IV complexes, [V^VO(β-tocDEA] and [V^IVO(β-tocDPA] have been synthesized and characterized by Nuclear Magnetic Resonance (NMR), Ultra Violet-Visible (UV-Vis) and Electron Paramagnetic Resonance (EPR) spectroscopies. Although the β-tocopherol compounds exhibit antioxidant activity their complexes induce formation of radicals. In addition, two vanadium amphiphilic complexes of 2,2'-((2-hydroxyoctadecyl)azanediyl)bis(ethan-1-ol) (C18DEA) and 1-(bis(pyridin-2-ylmethyl)amino)octadecan-2-ol (C18DPA) known to activate O₂ and produce ROS were synthesized and characterized (C. Drouza, A. Dieronitou, I. Hadjiadamou, M. Stylianou, J. Agric. Food. Chem., vol. 65, 2017, pp. 4942-4951). The four amphiphilic vanadium complexes exhibit enhanced hydrolytic stability. All compounds found to be cytotoxic for cancer cells exhibiting activity similar or higher to cis-platin.

The Protective Effect of Vanadium on Cognitive Impairment and the Neuropathology of Alzheimer's Disease in APPSwe/PS1dE9 Mice

Alzheimer's disease (AD) is a widely distributed neurodegenerative disease characterized clinically by cognitive deficits and pathologically by formation of amyloid-β (Aβ) plaque and neurofibrillary tangles (NFTs) in the brain. Vanadium is a biological trace element that has a function to mimic insulin for diabetes. Bis(ethylmaltolato) oxidovanadium (IV) (BEOV) has been reported to have a hypoglycemic property, but its effect on AD remains unclear. In this study, BEOV was supplemented at doses of 0.2 and 1.0 mmol/L to the AD model mice APPSwe/PS1dE9 for 3 months. The results showed that BEOV substantially ameliorated glucose metabolic disorder as well as synaptic and behavioral deficits of the AD mice. Further investigation revealed that BEOV significantly reduced Aβ generation by increasing the expression of peroxisome proliferator-activated receptor gamma and insulin-degrading enzyme and by decreasing β-secretase 1 in the hippocampus and cortex of AD mice. BEOV also reduced tau hyperphosphorylation by inhibiting protein tyrosine phosphatase-1B and regulating the pathway of insulin receptor/insulin receptor substrate-1/protein kinase B/glycogen synthase kinase 3 beta. Furthermore, BEOV could enhance autophagolysosomal fusion and restore autophagic flux to increase the clearance of Aβ deposits and phosphorylated tau in the brains of AD mice. Collectively, the present study provides solid data for revealing the function and mechanism of BEOV on AD pathology.

Synthesis of new multivalent metal ion functionalized mesoporous silica and studies of their enhanced antimicrobial and cytotoxicity activities

In the present study, we have reported the synthesis of a transition metal (Me = Ti, V, and Pd) incorporated into MCM-41 mesoporous molecular sieves (Si/Me = 20) synthesized by the sol-gel method. Their physicochemical properties were studied in detail by standard techniques like low angle powder X-ray diffraction (XRD), scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDXS), transmission electron microscopy (TEM), N₂ adsorption/desorption studies, and thermogravimetric-differential thermal (TG-DTA) analysis and spectral studies like Fourier transform infrared spectroscopic analysis (FT-IR), diffuse reflectance ultraviolet-visible spectroscopic analysis (UV-Visible-DRS), and X-ray photoelectron spectroscopy (XPS). The XRD patterns prove that the material's phase identity is the same irrespective of metal incorporation. SEM displayed the uniform shape and size of the nanoparticles. The presence of elements such as Ti, V, Pd, Si and O in respective materials is revealed using the EDXS analysis. Around 30% weight loss arose upon calcination from room temperature to 800 °C. BET surface area analysis presented that the parent materials have a high surface area (1024 m² g^-1) which was reduced upon metal incorporation. FT-IR analysis exhibited the framework vibrations of the synthesised materials. UV-Visible-DRS analysis indicated the presence of tetrahedrally coordinated transition metal ions. The multivalent-metal-ion-functionalized mesoporous materials showed significant enhancement in potent antimicrobial and anticancer activity. The antimicrobial activity is because of its low lipophilicity, which no longer allows the materials to enter via the lipid membrane. Thus, the new materials neither obstruct the metal-binding sites nor inhibit the growth of microbe enzymes. Further, the results show that the transition metal ion-containing mesoporous materials possessing good anticancer activity arising from their excessive surface area to volume ratio provided appropriate association with a tumour cell due to the direct penetration of mesoporous materials into the cell wall, causing membrane damage and cell death.

Effects of vanadium(IV) compounds on plasma membrane lipids lead to G protein-coupled receptor signal transduction

Luteinizing hormone receptors (LHR), expressed at physiological numbers <30,000 receptors per cell, translocate to and signal within membrane rafts following binding of human chorionic gonadotropin (hCG). Similarly LHR signal in cells when treated with bis(maltolato)oxovanadium(IV) (BMOV), bis(ethylmaltolato)oxovanadium(IV) (BEOV) or VOSO₄, which decrease membrane lipid packing. Overexpressed LHR (>85,000 receptors per cell) are found in larger clusters in polarized homo-transfer fluorescence resonance energy transfer (homo-FRET) studies that were not affected by either hCG or vanadium compounds. Intracellular cyclic adenylate monophosphate (cAMP) levels indicate that only clustered LHR are active and produce the intracellular second messenger, cAMP. When LHR are over-expressed, cell signaling is unaffected by binding of hCG or vanadium compounds. To confirm the existence of intact complex, the EPR spectra of vanadium compounds in cell media were obtained using 1 mM BMOV, BEOV or VOSO₄. These data were used to determine intact complex in a 10 μM solution and verified by speciation calculations. Effects of BMOV and BEOV samples were about two-fold greater than those of aqueous vanadium(IV) making it likely that intact vanadium complex are responsible for effects of LHR function. This represents a new mechanism for activation of a G protein-coupled receptor; perturbations in the lipid bilayer by vanadium compounds lead to aggregation and accumulation of physiological numbers of LHR in membrane raft domains where they initiate signal transduction and production of cAMP, a second messenger involved in signaling.

The First-Row Transition Metals in the Periodic Table of Medicine

In this manuscript, we describe medical applications of each first-row transition metal including nutritional, pharmaceutical, and diagnostic applications. The 10 first-row transition metals in particular are found to have many applications since there five essential elements among them. We summarize the aqueous chemistry of each element to illustrate that these fundamental properties are linked to medical applications and will dictate some of nature’s solutions to the needs of cells. The five essential trace elements—iron, copper, zinc, manganese, and cobalt—represent four redox active elements and one redox inactive element. Since electron transfer is a critical process that must happen for life, it is therefore not surprising that four of the essential trace elements are involved in such processes, whereas the one non-redox active element is found to have important roles as a secondary messenger.. Perhaps surprising is the fact that scandium, titanium, vanadium, chromium, and nickel have many applications, covering the entire range of benefits including controlling pathogen growth, pharmaceutical and diagnostic applications, including benefits such as nutritional additives and hardware production of key medical devices. Some patterns emerge in the summary of biological function andmedical roles that can be attributed to small differences in the first-row transition metals.

Metvan, bis(4,7-Dimethyl-1,10-phenanthroline)sulfatooxidovanadium(IV): DFT and Spectroscopic Study-Antitumor Action on Human Bone and Colorectal Cancer Cell Lines

The complex bis(4,7-dimethyl-1,10-phenantroline)sulfatooxidovanadium(IV), commonly known as Metvan, was prepared using a known synthetic procedure. Its optimized molecular structure was obtained by DFT calculations, as it was impossible to grow single crystals adequate for a crystallographic study. The complex was also characterized by a detailed analysis of its infrared spectrum, supported by the theoretical calculations, and also by some data derived from its Raman spectrum. In addition, cytotoxicity studies were performed using human osteosarcoma (MG-63) and human colorectal adenocarcinoma (HT-29) cell lines. The results show that Metvan impaired cell viability of both cancer cell lines in a low concentration range (0.25-5.0 μM).