Impact of Molybdenum Compounds as Anticancer Agents

Effect of Lanthanide Ions and Triazole Ligands on the Molecular Properties, Spectroscopy and Pharmacological Activity

The effect of La, Ce, Pr and Nd ions on four Ln(ligand)3 complexes and at three DFT levels of calculation was analyzed. Four ligands were chosen, three of which were based on the 1,2,3-triazole ring. The DFT methods used were B3LYP, CAM-B3LYP and M06-2X. The relationships established were between the geometric parameters, atomic charges, HOMO-LUMO energies and other molecular properties. These comparisons and trends will facilitate the synthesis of new complexes by selecting the ligand and lanthanide ion best suited to the desired property of the complex. The experimental IR and Raman spectra of Ln(2b')3 complexes where Ln = La, Ce, Pr, Nd, Sm, Gd, Dy, Ho and Er ions have been recorded and compared to know the effect of the lanthanide ion on the complex. The hydration in these complexes was also analyzed. Additionally, the effect of the type of coordination center on the ability of an Ln(ligand)3 complex to participate in electron exchange and hydrogen transfer was investigated using two in vitro model systems-DPPH and ABTS.

Biomonitoring Study of Toxic Metal(loid)s: Levels in Lung Adenocarcinoma Patients

Lung cancer is a leading cause of cancer deaths worldwide. The aim of this study was to investigate heavy metal(loid)s (Cd, Pb, Hg, Cr, Mn, Mo, Ni, and As) in lung cancer patients in order to elucidate their role as lung cancer environmental risk factors. Sixty-three patients of both sexes with adenocarcinoma stage IIIB or IV were enrolled in this research. The heavy metal(loid) urine concentrations were measured using ICP-MS. Arsenic was quantified above 10 μg/L in 44.44% of the samples. Nickel urinary concentrations above the ToxGuide reference levels were found in 50.79% of the samples, while lead was quantified in 9.52% of the urine samples. The urinary chromium levels were above the mean ToxGuide levels in 41.27% of the patients and were significantly higher in men in comparison with women (p = 0.035). The chromium urinary concentrations were positively associated with the CRP serum levels (p = 0.037). Cadmium was quantified in 61.90% of the samples with levels significantly higher in females than in males (p = 0.023), which was associated with smoking habits. Mercury was measured above the limit of quantification in 63.49% of the samples and was not associated with amalgam dental fillings. However, the Hg urinary concentrations were correlated positively with the ALT (p = 0.02), AST (p < 0.001), and GGT (p < 0.001) serum levels. In 46.03% of the samples, the Mo concentrations were above 32 μg/L, the mean value for healthy adults according to the ToxGuide, and 9.52% of the patients had Mn levels higher than 8 μg/L, the reference value for healthy adults based on ToxGuide data. The obtained results are preliminary, and further studies are needed to have a deeper insight into metal(loid) exposure's association with lung cancer development, progression, and survival prediction.

Domestic dogs as environmental sentinel in comparative toxicologic pathology: Assessment of metals and rare earth elements concentrations in healthy and neoplastic mammary glands

Quantification of trace element concentrations in human and animal tissues has acquired great importance in the last few years, considering the pivotal role of these elements in several physiological and pathological processes. Variations in their concentrations appear to have a role in the development and advancement of diseases in both humans and animals, for example, cancer. The purpose of this study was to investigate the concentration of rare earth elements and metals in healthy and neoplastic Formalin-Fixed Paraffin-Embedded (FFPE) mammary gland tissue of dogs. All samples were processed to have a quantitative determination of inorganic elements including metals of known toxicological interest such as Pb, Cd, Tl, As, Hg, the trace elements Mn, Fe, Co, Cu, Zn, Se, and other elements including Cr, V, Mo, Ni, Sb, W, Sn. Moreover, rare earth elements (REEs) (Sc, Y, Lu, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) were also investigated. Cu and Mo concentrations in mammary cancerous tissue were greater than those in normal mammary glands (p < 0.05). In non-neoplastic tissue increased concentrations of Cd, Co, Ni, Tl, and V were also reported (p < 0.05). The mammary tissue of healthy individuals had greater concentrations of REEs than the neoplastic mammary glands (p < 0.05). The results of our study confirmed differences in mammary inorganic element concentrations between healthy and neoplastic groups, highlighting the potential relevance of these fluctuations in toxicologic pathology.

Molybdenum Complexes Derived from 2-Hydroxy-5-nitrobenzaldehyde and Benzhydrazide as Potential Oxidation Catalysts and Semiconductors

This study aimed to synthesize molybdenum complexes coordinated with an aroyl hydrazone-type ligand (H2L), which was generated through the condensation of 2-hydroxy-5-nitrobenzaldehyde with benzhydrazide. The synthesis yielded two types of mononuclear complexes, specifically [MoO2(L)(MeOH)] and [MoO2(L)(H2O)], as well as a bipyridine-bridged dinuclear complex, [(MoO2(L))2(4,4'-bpy)]. Those entities were thoroughly characterized using a suite of analytical techniques, including attenuated total reflectance infrared spectroscopy (IR-ATR), elemental analysis (EA), thermogravimetric analysis (TGA), and single-crystal X-ray diffraction (SCXRD). Additionally, solid-state impedance spectroscopy (SS-IS) was employed to investigate the electrical properties of these complexes. The mononuclear complexes were tested as catalysts in the epoxidation of cyclooctene and the oxidation of linalool. Among these, the water-coordinated mononuclear complex, [MoO2(L)(H2O)], demonstrated superior electrical and catalytic properties. A novel contribution of this research lies in establishing a correlation between the electrical properties, structural features, and the catalytic efficiency of the complexes, marking this work as one of the pioneering studies in this area for molybdenum coordination complexes, to the best of our knowledge.

Association of urinary arsenic, polycyclic aromatic hydrocarbons, and metals with cancers among the female population in the US

BACKGROUND

Cancers that primarily affect women in the US include breast, uterine, and cervical cancers. There may be associations between these different types of cancer in women and environmental pollutant exposure.

PURPOSE

This study aimed to assess seven species of arsenic, six polycyclic aromatic hydrocarbon (PAH) compounds, and fourteen different metal concentrations in urine and their correlation with cancer among women.

METHODS

We conducted a cross-sectional analysis using 2011--2012 to 2015-2016 National Health and Nutrition Examination Survey data (n = 4,956) and logistic regression modeling of the complex weighted survey design.

RESULTS

Breast cancer was inversely correlated with arsenocholine (3rd quantile), monomethylarsonic acid (4th quantile), manganese (4th quantile), and antimony (3rd, 4th quantiles). Cervical cancer was inversely correlated with 3-hydroxyfluorene (3rd quantile), molybdenum (2nd, 4th quantiles), antimony (3rd quantile), tin (4th quantile), and thallium (4th quantile) exposure and positively associated with arsenic acid (3rd quantile), arsenobetaine (2nd, 4th quantiles). Uterine cancer was correlated with 1-hydroxynaphthalene (3rd, 4th quantiles), 2-hydroxynaphthalene (4th quantile), 1-hydroxyphenathrene (2nd, 4th quantiles), 1-hydroxypyrene (3rd quantile), cobalt (2nd, 3rd quantiles) and inversely with mercury (4th quantile).

CONCLUSION

This study determined breast cancer and arsenic and some metal species exposure, indicating an inverse association. Arsenic acid and arsenobetaine exposure showed a positive correlation with cervical cancer. For uterine cancer, the correlations for the PAH compounds and cobalt showed a positive correlation, and the arsenic species and mercury were inversely associated. Further research is required to establish or refute the findings.

Mechanisms of cell injury induced by inhaled molybdenum trioxide nanoparticles in Golden Syrian Hamsters

Molybdenum trioxide nanoparticles (MoO₃ NPs) are extensively used in the biomedical, agricultural, and engineering fields that may increase exposure and adverse health effects to the human population. The purpose of this study is to evaluate a possible molecular mechanism leading to cell damage and death following pulmonary exposure to inhaled MoO₃ NPs. Animals were separated into four groups: two control groups exposed to room air or aerosolized water and two treated groups exposed to aerosolized MoO₃ NPs with a concentration of 5 mg/m³ NPs (4 h/day for eight days) and given a one-day (T-1) or seven-day (T-7) recovery period post exposure. Pulmonary toxicity was evaluated with total and differential cell counts. Increases were seen in total cell numbers, neutrophils, and multinucleated macrophages in the T-1 group, with increases in lymphocytes in the T-7 group (*P < 0.05). To evaluate the mechanism of toxicity, protein levels of Beclin-1, light chain 3 (LC3)-I/II, P-62, cathepsin B, NLRP3, ASC, caspase-1, interleukin (IL)-1β, and tumor necrosis factor-α (TNF-α) were assessed in lung tissue. Immunoblot analyses indicated 1.4- and 1.8-fold increases in Beclin-1 in treated groups (T-1 and T-7, respectively, *P < 0.05), but no change in protein levels of LC3-I/II in either treated group. The levels of cathepsin B were 2.8- and 2.3-fold higher in treated lungs (T-1 and T-7, respectively, *P < 0.05), the levels of NLRP3 had a fold increase of 2.5 and 3.6 (T-1 *P < 0.05, T-7 **P < 0.01, respectively), and the levels of caspase-1 indicated a 3.8- and 3.0-fold increase in treated lungs (T-1 and T-7, respectively, *P < 0.05). Morphological changes were studied using light and electron microscopy showing alterations to airway epithelium and the alveoli, along with particle internalization in macrophages. The results from this study may indicate that inhalation exposure to MoO₃ NPs may interrupt the autophagic flux and induce cytotoxicity and lung injury through pyroptosis cell death and activation of caspase-1.

Enhanced Anticancer Performance of Eco-Friendly-Prepared Mo-ZnO/RGO Nanocomposites: Role of Oxidative Stress and Apoptosis

ZnO nanoparticles (NPs) have attracted great attention in cancer therapy because of their novel and tailorable physicochemical features. Pure ZnO NPs, molybdenum (Mo)-doped ZnO NPs, and Mo-ZnO/reduced graphene oxide nanocomposites (Mo-ZnO/RGO NCs) were prepared using a facile, inexpensive, and eco-friendly approach using date palm (Phoenix dactylifera L.) fruit extract. Anticancer efficacy of green synthesized NPs/NCs was examined in two different cancer cells. The potential mechanism of the anticancer activity of green synthesized NPs/NCs was explored through oxidative stress and apoptosis. The syntheses of pure ZnO NPs, Mo-ZnO NPs, and Mo-ZnO/RGO NCs were confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and photoluminescence (PL). Dynamic light scattering (DLS) study indicated the excellent colloidal stability of green prepared samples. Mo-ZnO/RGO NCs exhibited threefold higher anticancer activity in human colon (HCT116) and breast (MCF7) cancer cells as compared to pure ZnO NPs. The anticancer activity of Mo-ZnO/RGO NCs was mediated through reactive oxygen species, p53, and the caspase-3 pathway. Moreover, cytocompatibility of Mo-ZnO/RGO NCs in human normal colon epithelial (NCM460) and normal breast epithelial cells (MCF10A) was much better than those of pure ZnO NPs. Altogether, green stabilized Mo-ZnO/RGO NCs exhibited enhanced anticancer performance and improved cytocompatibility because of green mediated good synergism between ZnO, Mo, and RGO. This study suggested the high nutritional value fruit-based facile preparation of ZnO-based nanocomposites for cancer therapy.

Mo(VI) Potential Metallodrugs: Explaining the Transport and Cytotoxicity by Chemical Transformations

The transport and cytotoxicity of molybdenum-based drugs have been explained with the concept of chemical transformation, a very important idea in inorganic medicinal chemistry that is often overlooked in the interpretation of the biological activity of metal-containing systems. Two monomeric, [MoO₂(L¹)(MeOH)] (1) and [MoO₂(L²)(EtOH)] (2), and two mixed-ligand dimeric Mo^VIO₂ species, [{MoO₂(L^1-2)}₂(μ-4,4'-bipy)] (3-4), were synthesized and characterized. The structures of the solid complexes were solved through SC-XRD, while their transformation in water was clarified by UV-vis, ESI-MS, and DFT. In aqueous solution, 1-4 lead to the penta-coordinated [MoO₂(L^1-2)] active species after the release of the solvent molecule (1 and 2) or removal of the 4,4'-bipy bridge (3 and 4). [MoO₂(L^1-2)] are stable in solution and react with neither serum bioligand nor cellular reductants. The binding affinity of 1-4 toward HSA and DNA were evaluated through analytical and computational methods and in both cases a non-covalent interaction is expected. Furthermore, the in vitro cytotoxicity of the complexes was also determined and flow cytometry analysis showed the apoptotic death of the cancer cells. Interestingly, μ-4,4'-bipy bridged complexes 3 and 4 were found to be more active than monomeric 1 and 2, due to the mixture of species generated, that is [MoO₂(L^1-2)] and the cytotoxic 4,4'-bipy released after their dissociation. Since in the cytosol neither the reduction of Mo^VI to Mo^V/IV takes place nor the production of reactive oxygen species (ROS) through Fenton-like reactions of 1-4 with H₂O₂ occurs, the mechanism of cytotoxicity should be attributable to the direct interaction with DNA that happens with a minor-groove binding which results in cell death through an apoptotic mechanism.

Bioactive glasses incorporating less-common ions to improve biological and physical properties

Bioactive glasses (BGs) have been a focus of research for over five decades for several biomedical applications. Although their use in bone substitution and bone tissue regeneration has gained important attention, recent developments have also seen the expansion of BG applications to the field of soft tissue engineering. Hard and soft tissue repair therapies can benefit from the biological activity of metallic ions released from BGs. These metallic ions are incorporated in the BG network not only for their biological therapeutic effects but also in many cases for influencing the structure and processability of the glass and to impart extra functional properties. The "classical" elements in silicate BG compositions are silicon (Si), phosphorous (P), calcium (Ca), sodium (Na), and potassium (K). In addition, other well-recognized biologically active ions have been incorporated in BGs to provide osteogenic, angiogenic, anti-inflammatory, and antibacterial effects such as zinc (Zn), magnesium (Mg), silver (Ag), strontium (Sr), gallium (Ga), fluorine (F), iron (Fe), cobalt (Co), boron (B), lithium (Li), titanium (Ti), and copper (Cu). More recently, rare earth and other elements considered less common or, some of them, even "exotic" for biomedical applications, have found room as doping elements in BGs to enhance their biological and physical properties. For example, barium (Ba), bismuth (Bi), chlorine (Cl), chromium (Cr), dysprosium (Dy), europium (Eu), gadolinium (Gd), ytterbium (Yb), thulium (Tm), germanium (Ge), gold (Au), holmium (Ho), iodine (I), lanthanum (La), manganese (Mn), molybdenum (Mo), nickel (Ni), niobium (Nb), nitrogen (N), palladium (Pd), rubidium (Rb), samarium (Sm), selenium (Se), tantalum (Ta), tellurium (Te), terbium (Tb), erbium (Er), tin (Sn), tungsten (W), vanadium (V), yttrium (Y) as well as zirconium (Zr) have been included in BGs. These ions have been found to be particularly interesting for enhancing the biological performance of doped BGs in novel compositions for tissue repair (both hard and soft tissue) and for providing, in some cases, extra functionalities to the BG, for example fluorescence, luminescence, radiation shielding, anti-inflammatory, and antibacterial properties. This review summarizes the influence of incorporating such less-common elements in BGs with focus on tissue engineering applications, usually exploiting the bioactivity of the BG in combination with other functional properties imparted by the presence of the added elements.