Biometals最新文献

Phytoextraction of lead (Pb) is a challenging task due to its extremely low mobility within soil and plant systems. In this study, we tested the influence of some novel chelating agents for Pb-phytoextraction using sunflower. The Pb was applied at control (0.0278 mM) and 4.826 mM Pb as Pb(NO₃)₂ through soil-spiking. After 10 days of Pb addition, four different organic ligands (aspartic, ascorbic, tartaric, and pantothenic acids) were added to the soil at 1 mM concentration each. respectively. In the absence of any chelate, sunflower plants grown at 4.826 mM Pb level accumulated Pb concentrations up to 104 µg g⁻¹ DW in roots, whereas 64 µg g⁻¹ DW in shoot. By contrast, tartaric acid promoted significantly Pb accumulation in roots (191 µg g⁻¹ DW; + 45.5%) and shoot (131.6 µg g⁻¹ DW; + 51.3%). Pantothenic acid also resulted in a significant Pb-uptake in the sunflower shoots (123 µg g⁻¹ DW; + 47.9%) and in roots (177.3 µg g⁻¹ DW; + 41.3%). The least effective amongst the chelates tested was aspartic acid, but it still contributed to + 40.1% more Pb accumulation in the sunflower root and shoots. In addition, plant growth, biochemical, and ionomic parameters were positively regulated by the organic chelates used. Especially, an increase in leaf Ca, P, and S was evident in Pb-stressed plants in response to chelates. These results highlight that the use of biocompatible organic chelates positively alters plant physio-biochemical traits contributing to higher Pb-sequestration in sunflower plant parts.

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Previous studies have demonstrated that the hippocampus, a crucial region for memory and cognitive functions, is particularly vulnerable to adverse effects of exposure to heavy metals. Nickel (Ni) is a neurotoxic agent that, primarily induces oxidative stress, a process known to contribute to cellular damage, which consequently affects neurological functions. The antioxidant properties of melatonin are a promising option for preventing the adverse effects of Ni, especially by protecting cells against oxidative stress and related damage. In our investigation of the potential neuroprotective effects of melatonin against Ni-induced neurotoxicity, we chose to administer melatonin through intraperitoneal injection in rats following an intrahippocampal injection of Ni into the left hippocampus. This approach allows us a targeted investigation into the influence of melatonin on the neurotoxic effects of Ni, particularly within the crucial context of the hippocampus. In the present study, we demonstrated that melatonin efficiency reduced lactate dehydrogenase level, and preserved antioxidant enzyme activities in Ni-exposed hippocampal tissue. It also mitigated the decline in superoxide dismutase and catalase activities. On the other hand, melatonin could act directly by reducing reactive oxygen species Ni-induced overproduction. Taking to gather these two potential mechanisms of action could be responsible for the adverse effect of Ni on the behavioral alteration observed in our study. This study provides significant insights into the potential of melatonin to mitigate the detrimental effects of Ni on the brain, particularly into the hippocampal region, suggesting its possible implications for the treatment of neurological disorders related to Ni exposure.

Selenium (Se) is a beneficial trace element for plants, while zinc (Zn) is a vital micronutrient. Bletilla striata (Thunb.) Reichb. F. is widely recognized as a medicinal herb. In this study, Se and Zn were introduced to determine the medicinal properties of B. striata. The plant’s biomass, polysaccharides, Se and Zn contents, and the antioxidant properties of polysaccharide solutions were all examined. A notable increase in polysaccharide synthesis in B. striata tubers was observed following the application of 0.2 kg ha⁻¹ of Se, and 1.0 kg ha⁻¹ of Zn, either individually or in combination. Se and Zn content in polysaccharides were 3.33 to 3.77 mg kg⁻¹ and 82.82 to 121.78 mg kg⁻¹, at 1.0 kg ha⁻¹ Se and 10.0 kg ha⁻¹ Zn treatments, respectively. These values were 2.1–3.1 times and 1.8–2.8 times higher than those observed in control samples. Polysaccharide antioxidation has resulted in an increase in antioxidant activity as the concentration of polysaccharide solutions increased. The largest scavenging of 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals and the most excellent reducing power of the polysaccharide solutions were observed when a mixture of Se and Zn was applied at a rate of 1.0 kg ha⁻¹ and 10.0 kg ha⁻¹. The individual application of Se at 1.0 kg ha⁻¹ and Zn at 10.0 kg ha⁻¹ also resulted in significant DPPH radicals scavenging and reduced power. These data suggested that Se-Zn enriched B. striata is a new source of Se and Zn supplementation and an antioxidant resource.

In the present manuscript, novel macrocyclic Schiff base complexes [Zn(N₄MacL₁)Cl₂–Zn(N₄MacL₃)Cl₂] were synthesized by the reaction of ZnCl₂ and macrocyclic ligands (N₄MacL₁–N₄MacL₃) derived from diketone and diamines under microwave irradiation method and conventional method. The structures of the obtained complexes were identified by various spectrometric methods such as Fourier transformation infra-red (FT-IR), nuclear magnetic resonance (NMR), high-resolution mass spectrometry (HR-MS), powder X-ray diffraction, molar conductivity, and UV–vis. The structures of the synthesized compounds were optimized by using the def2–TZV/J and def2–SVP/J Coulomb fitting basis sets at B3LYP level in density functional theory (DFT) calculations. The macrocyclic Schiff base complexes exhibited higher activities against Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus), Gram-negative bacteria (Escherichia coli and Xanthomonas campestris), and fungal strains (Fusarium oxysporum and Candida albicans) in comparison to macrocyclic Schiff base ligands. Furthermore, the newly synthesized macrocyclic compounds were assessed for their anticancer activity against three cell lines: A549 (human alveolar adenocarcinoma epithelial cell line), HT-29 (human colorectal adenocarcinoma cell line), and MCF-7 (human breast adenocarcinoma cell line) using the MTT assay. The obtained results showed that the macrocyclic complex [Zn(N₄MacL₃)Cl₂] displayed the highest cytotoxic activity (2.23 ± 0.25 µM, 6.53 ± 0.28 µM, and 7.40 ± 0.45 µM for A549, HT-29, and MCF-7 cancer cell lines, respectively). Additionally, molecular docking investigations were conducted to elucidate potential molecular interactions between the synthesized macrocyclic compounds and target proteins. The results revealed a consistent agreement between the docking calculations and the experimental data.

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Candida species undeniably rank as the most prevalent opportunistic human fungal pathogens worldwide, with Candida albicans as the predominant representative. However, the emergence of non-albicans Candida species (NACs) has marked a significant shift, accompanied by rising incidence rates and concerning trends of antifungal resistance. The search for new strategies to combat antifungal-resistant Candida strains is of paramount importance. Recently, our research group reported the anti-Candida activity of a coordination compound containing copper(II) complexed with theophylline (theo) and 1,10-phenanthroline (phen), known as “CTP” – Cu(theo)₂phen(H₂O).5H₂O. In the present work, we investigated the mechanisms of action of CTP against six medically relevant, antifungal-resistant NACs, including C. auris, C. glabrata, C. haemulonii, C. krusei, C. parapsilosis and C. tropicalis. CTP demonstrated significant efficacy in inhibiting mitochondrial dehydrogenases, leading to heightened intracellular reactive oxygen species production. CTP treatment resulted in substantial damage to the plasma membrane, as evidenced by the passive incorporation of propidium iodide, and induced DNA fragmentation as revealed by the TUNEL assay. Scanning electron microscopy images of post-CTP treatment NACs further illustrated profound alterations in the fungal surface morphology, including invaginations, cavitations and lysis. These surface modifications significantly impacted the ability of Candida cells to adhere to a polystyrene surface and to form robust biofilm structures. Moreover, CTP was effective in disassembling mature biofilms formed by these NACs. In conclusion, CTP represents a promising avenue for the development of novel antifungals with innovative mechanisms of action against clinically relevant NACs that are resistant to antifungals commonly used in clinical settings.

The liver damage caused by Diabetes Mellitus (DM) has attracted increasing attention in recent years. Liver injury in DM can be caused by ferroptosis, a form of cell death caused by iron overload. However, the role of iron transporters in this context is still not clear. Herein, we attempted to shed light on the pathophysiological mechanism of ferroptosis. DM was induced in 8-week-old male rats by streptozotocin (STZ) before assessment of the degree of liver injury. Together with histopathological changes, variations in glutathione peroxidase 4 (GPX4), glutathione (GSH), superoxide dismutase (SOD), transferrin receptor 1 (TFR1), ferritin heavy chain (FTH), ferritin light chain (FTL), ferroportin and Prussian blue staining, were monitored in rat livers before and after treatment with Fer-1. In the liver of STZ-treated rats, GSH and SOD levels decreased, whereas those of malondialdehyde (MDA) increased. Expression of TFR1, FTH and FTL increased whereas that of glutathione peroxidase 4 (GPX4) and ferroportin did not change significantly. Prussian blue staining showed that iron levels increased. Histopathology showed liver fibrosis and decreased glycogen content. Fer-1 treatment reduced iron and MDA levels but GSH and SOD levels were unchanged. Expression of FTH and FTL was reduced whereas that of ferroportin showed a mild decrease. Fer-1 treatment alleviated liver fibrosis, increased glycogen content and mildly improved liver function. Our study demonstrates that ferroptosis is involved in DM-induced liver injury. Regulating the levels of iron transporters may become a new therapeutic strategy in ferroptosis-induced liver injury.

Schiff bases of existing antimicrobial drugs are an area, which is still to be comprehensively explored to improve drug efficiency against consistently resisting bacterial species. In this study, we have targeted a new and eco-friendly method of condensation reaction that allows the "green synthesis" as well as improved biological efficacy. The transition metal complexes of cefpodoxime with well-enhanced biological activities were synthesized. The condensation reaction product of cefpodoxime and vanillin was further reacted with suitable metal salts of [Mn (II), Cu (II), Fe (II), Zn (II), and Ni (II)] with 1:2 molar ratio (metal: ligand). The characterization of all the products were carried out by using UV–Visible, elemental analyzer, FTIR, ¹H-NMR, ICP-OES, and LC–MS. Electronic data obtained by UV–Visible proved the octahedral geometry of metal complexes. The biological activities Schiff base ligand and its transition metal complexes were tested by using in-vitro anti-bacterial analysis against various Gram-negative, as well as Gram-positive bacterial strains. Proteinase and protein denaturation inhibition assays were utilized to evaluate the products in-vitro anti-inflammatory activities. The in vitro antioxidant activity of the ligand and its complexes was evaluated by utilizing the 2,2-diphenyl-1-picrylhydrazyl (DPPH) in-vitro method. The final results proved metal complexes to be more effective against bacterial microorganisms as compared to respective parent drug as well as their free ligands. Patch Dock, a molecular docking tool, was used to dock complexes 1a-5e with the crystal structure of GlcN-6-P synthase (ID: 1MOQ). According to the docking results, complex 2b exhibited a highest score (8,882; ACE = –580.43 kcal/mol) that is well correlated with a high inhibition as compared to other complexes which corresponds to the antibacterial screening outcomes.

The indigenous halophilic arsenite-resistant bacterium Halomonas elongata strain SEK2 isolated from the high saline soil of Malek Mohammad hole, Lut Desert, Iran, could tolerate high concentrations of arsenate (As⁵⁺) and arsenite (As³⁺) up to 800 and 40 mM in the SW-10 agar medium, respectively. The isolated strain was able to tolerate considerable concentrations of other toxic heavy metals and oxyanions, including Cadmium (Cd²⁺), Chromate (Cr⁶⁺), lead (Pb²⁺), and selenite (Se⁴⁺), regarding the high salinity of the culture media (with a total salt concentration of 10% (w/v)), the tolerance potential of the isolate SEK2 was unprecedented. The bioremoval potential of the isolate SEK2 was examined through the Silver diethyldithiocarbamate (SDDC) method and demonstrated that the strain SEK2 could remove 60% of arsenite from arsenite-containing growth medium after 48 h of incubation without converting it to arsenate. The arsenite adsorption or uptake by the halophilic bacterium was investigated and substantiated through Fourier-transform infrared spectroscopy (FTIR), Scanning Electron Microscope (SEM), and Energy Dispersive X-ray (EDX) analyses. Furthermore, Transmission electron microscope (TEM) analysis revealed ultra-structural alterations in the presence of arsenite that could be attributed to intracellular accumulation of arsenite by the bacterial cell. Genome sequencing analysis revealed the presence of arsenite resistance as well as other heavy metals/oxyanion resistance genes in the genome of this bacterial strain. Therefore, Halomonas elongata strain SEK2 was identified as an arsenite-resistant halophilic bacterium for the first time that could be used for arsenite bioremediation in saline arsenite-polluted environments.