Biometals最新文献

Describe the levels of arsenic, mercury, manganese, and lead in the hair of older Mexican adults and analyze their association with exposure and sociodemographic factors. This cross-sectional study used a random subsample of 2474 adults aged 50 and older from the 2018 Mexican Health and Aging Study. Metal levels in hair were quantified using inductively coupled plasma mass spectrometry and an optical emission spectrometer with a hydride generator. Linear regression models were used to assess the associations between metal/metalloid levels and sociodemographic factors. Median hair levels were arsenic 0.04 μg/g, mercury 0.14 μg/g, manganese 0.79 μg/g, and lead 0.65 μg/g. Arsenic levels increased with age, while manganese and lead levels decreased. Males exhibited higher concentrations of all metalloids/metals compared to females. BMI was associated with increased arsenic levels. The use of wood or charcoal for cooking was associated with increased hair manganese. Household pesticide use was associated with elevated levels of mercury, manganese, and lead. Cooking with glazed clay pots was associated with increased lead levels. Residing near exposure sites increased mercury, manganese, and lead levels in hair. Additionally, seven or more years of schooling was associated with increased mercury levels, while low/middle socioeconomic status was associated with increased hair manganese levels. The results reveal significant metal exposure in older Mexican adults, varying according to sociodemographic and exposure factors. These findings underscore the need to implement public policies to reduce metal exposure and protect the health of these vulnerable communities.

Selenium’s role in aging is supported by its involvement in antioxidant defense, immune function, and cellular maintenance. Adequate selenium levels can contribute to healthier aging. This cross-sectional study investigated the associations of selenium status markers with anthropometric parameters, glycemic profile, and inflammatory biomarkers in 72 older adults living in nursing homes (NH). Plasma selenium levels were measured using inductively coupled plasma mass spectrometry, and selenoprotein P (SELENOP) was determined using enzyme-linked immunosorbent assay. Dietary selenium intake data were obtained by directly weighing the food at two different times, with an interval of 30 to 45 days between them. The mean age was 83 (8.6) years. The median (IQR) of plasma selenium levels was 88.20 (76.0–106.0)µg/L, for SELENOP 32.30 (29.2–33.5)ng/mL, and the mean (SD) of dietary selenium intake was 72.7 (11.9)µg/day. Overall, 65.2% of participants exhibited elevated glycated hemoglobin (HbA1c) levels. Insufficient plasma selenium levels to optimize SELENOP (< 100 μg/L) showed a significant association with being underweight (p = 0.04). Participants with low SELENOP and low dietary selenium intake had HbA1c levels above 6.4% (p = 0.05). Plasma selenium levels and dietary selenium intake were positively correlated with body mass index (ρ = 0.408, p = 0.001 and r = 0.382, p = 0.004, respectively). Selenium status markers were not associated with the inflammatory biomarkers. However, half of the population had high levels of IL-6 and TNF-α, and 98.5% had high levels of hs-CRP. In conclusion, lower plasma selenium was associated with underweight status, while reduced SELENOP and dietary selenium intake correlated with elevated HbA1c in older adults in NH.

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Lactoferrin (LF) is a glycoprotein found in neutrophils, milk, and various mammalian secretions that plays a crucial role in host defense by modulating the immune response. Previous studies have shown that LF is taken up by human monocytes and can be present in their nucleus. However, it is unclear whether the iron saturation levels or the protease activity of LF are involved in this uptake and nuclear translocation. In addition, the activation of monocytes might influence these processes. The present study investigated the uptake and nuclear translocation of bovine LF (bLF) and porcine LF (pLF) in porcine blood-derived monocytes and how this affects monocyte function. Both bLF and pLF were internalized by porcine monocytes. Their uptake was not affected by increased iron saturation levels or by inactivation of the proteolytic activity of LF. Similarly, LPS-induced activation of monocytes did not affect LF internalization. We further investigated whether bLF could modulate LPS-induced cytokine responses by monocytes. Across all tested LPS serotypes and concentrations, bLF failed to decrease the LPS-induced TNF-α secretion by porcine monocytes. Besides internalization, we found that bLF and pLF translocated to the nucleus in a subset of porcine monocytes. This nuclear translocation was not affected by the iron saturation level and proteolytic activity of LF, nor by LPS-induced monocyte activation. Together, these findings further deepen our understanding of LF’s interaction with porcine innate immune cells and provide insights into its immunomodulatory properties.

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Medicinal plants are valuable sources of bioactive compounds. In this study, we analyzed the levels of essential metals (Fe, Cu, Zn, Mn) in the leaves of Punica granatum, Teucrium montanum, Chaerophyllum coloratum, Petteria ramentacea, and Menyanthes trifoliata using atomic absorption spectrophotometry. Ethanolic leaf extracts were assessed for anti-inflammatory activity via bovine serum albumin BSA and egg albumin (EgA) denaturation assays and for antioxidant potential by hydroxyl radical scavenging using EPR (Electron Paramagnetic Resonance) spectroscopy. Metal concentrations varied across species: Fe (33–93 mg/kg), Cu (4.29–11.61 mg/kg), Zn (12.39–105 mg/kg), and Mn (1.38–1005 mg/kg), with T. montanum showing the highest Fe and M. trifoliata with highest Cu, Zn and Mn levels. Total phenolic content (TPC) ranged from 32 to 117 mg/g_DW, with the highest in P. granatum, which also demonstrated the strongest hydroxyl radical scavenging. The highest BSA inhibition (~ 80%) was observed in Ch. coloratum, P. granatum, and T. montanum at 0.01 µg/mL TPC. Egg albumin inhibition ranged from 28–50%, with Ch. coloratum being the most active. Significant correlations were found between Cu, Mn, and anti-inflammatory activity, and between Zn, TPC, and both antioxidant and anti-inflammatory effects. These findings suggest a synergistic role of phenolics and trace elements and support the potential use of these plants as dietary supplements against inflammation and oxidative stress.

Zinc (Zn²⁺) is the second most abundant trace element after iron, with most of it is stored in skeletal muscles. Although a large part of Zn²⁺ is tightly bound to metalloproteins, the small portion of free Zn²⁺ can participate in nerve signaling. Here we examined the effects of Zn²⁺ at nanomolar concentrations on neuromuscular transmission in the diaphragm, the main respiratory muscle. Zn²⁺ reduced spontaneous neurotransmitter release at both lowered and physiological external Ca²⁺ levels. Additionally, Zn²⁺ effectively decreased the probability of neurotransmitter release upon single nerve stimulation under lowered external Ca²⁺, and inhibited Ca²⁺-independent sucrose-induced exocytosis. At physiological external Ca²⁺ concentration, Zn²⁺ decreased neurotransmitter release during low-frequency stimulation. The reduction became increased during short trains of moderate-to-high frequency stimuli. Furthermore, Zn²⁺ diminished both neurotransmitter release and the participation of dye-labeled synaptic vesicles in exocytosis during prolonged nerve firing at moderate frequency. Zn²⁺ aggravated muscle fatigue and impaired contraction recovery upon nerve stimulation. This was linked to a reduction in peak inspiratory flow in mice, an indicator of diaphragm function, after injection of low-dose Zn²⁺. Our data suggest that at nanomolar concentrations, Zn²⁺ is a negative modulator of neuromuscular function.

Therapy resistance is a major challenge in cancer treatment, with multidrug resistance (MDR) being a well-characterized phenomenon wherein cancer cells develop resistance not only to the administered drug but also to structurally diverse compounds. Metal chelators, including quinolines and thiosemicarbazones, have shown broad antitumor activity and potential in overcoming MDR by modulating metal metabolism. However, predicting whether chelators increase or decrease toxicity in MDR cells remains complex, especially as chelator-metal complexes may become substrates for ATP-binding cassette (ABC) transporters, leading to resistance or hypersensitivity. In this study, we developed cell lines with comparable expression levels of the three major MDR ABC transporters (ABCB1, ABCC1, and ABCG2). Our findings demonstrated distinct transporter-specific influences on chelator toxicity. Cells expressing ABCC1 displayed significant resistance to thiosemicarbazones (Dp44mT, COTI-2, DpC) in both their metal-free and metal-bound forms. Vesicular transport assays further demonstrated that ABCC1 actively transports the Fe-GSH complex, formed under physiological glutathione levels, indicating its role in regulating the labile iron pool and reducing intracellular iron toxicity. These findings underscore the importance of transporter-chelator interactions in shaping drug resistance and sensitivity and highlight the intricate roles of ABC transporters in modulating chelator activity.

Diabetic retinopathy (DR) is a major microvascular complication of diabetes mellitus (DM). Evidence suggests that trace element imbalances may contribute to the development and progression of DR. This study aimed to evaluate the levels of selected trace elements in Iraqi patients with DM, with and without retinopathy, to identify potential biomarkers associated with disease progression. A total of 120 participants were involved and divided into three groups: healthy controls (n = 60), DM patients (n = 30), and DR patients (n = 30). Blood samples were analyzed for the concentrations of Cu, Zn, Mg, Pb, Cd, Ni, Cr, Co, Mn, and Al using flame and flameless atomic absorption spectrophotometry. DR patients showed elevated levels of Cu, Pb, Cd, Ni, and Al, and decreased levels of Zn, Mg, Cr, Co, and Mn compared to both DM and control groups (p < 0.05 or p < 0.01). Correlation analyses revealed distinct element interactions within DM and DR groups, particularly antagonistic relationships such as Cu–Zn and Zn–Co in DR patients. The study demonstrates a strong association between trace element dysregulation and diabetic retinopathy, suggesting that specific elements such as Cu, Zn, Mg and Co may serve as valuable indicators for monitoring disease progression. These findings strongly support further investigation into trace elements for the prevention and management of DR.

Chagas disease remains a major public health challenge, and there is a need for new therapeutic agents. N-heterocyclic carbene (NHC) complexes, particularly those linked to silver or gold, have shown significant anticancer, antimicrobial, and antiparasitic activities. This study aimed to evaluate the efficacy of four NHC compounds (QMT3, QMT4, QMT7, and QMT8) against Trypanosoma cruzi, the causative agent of Chagas disease. In vitro assays revealed that QMT3 and QMT8 exhibited the strongest antiparasitic effects, with QMT3 showing the highest potency and stability over time (IC₅₀ = 10.3 µg/mL at 24 h). Both compounds induced rapid, irreversible cell death in epimastigotes, primarily through late apoptotic-like and necrotic pathways, as evidenced by Annexin V/PI labeling. Additionally, treatment with QMT3 and QMT8 led to significant increases in intracellular reactive oxygen species (ROS), particularly superoxide (SO). Notably, both compounds displayed high specificity for the parasite with low cytotoxicity towards mammalian cells, although QMT8 was less toxic to host cells than QMT3 at short exposure times. Molecular modeling studies revealed that QMT3, and QMT8 bind to the active site of TryR, a crucial player in maintaining redox homeostasis in trypanosomatids, potentially competing with its natural ligand and disrupting its enzymatic function. These findings suggest that QMT3 and QMT8, silver- and gold-based NHC complexes, act through redox system disruption and TryR inhibition, positioning them as promising candidates for the development of new treatments for Chagas disease.

Chromium in its hexavalent form (Cr(VI)) is a highly toxic environmental pollutant that poses severe risks to human health and ecosystems. Staphylococcus aureus can play a role in the removal of Cr(VI) from aqueous solutions, primarily through a process of reduction and subsequent biosorption. While it’s not as widely studied for this purpose as some other bacterial species, it has been shown to reduce and bind Cr(VI), potentially offering a way to remediate contaminated environments. This study assessed the biosorption potential of the bacterial strain Staphylococcus aureus CC1956, which tolerates Cr(VI) levels up to 700 mg/L. The strain demonstrated significant Cr(VI) removal across various conditions, including pH values from 5.0 to 9.0, temperatures ranging from 25 to 45 °C, and initial Cr(VI) concentrations between 50 and 300 mg/L. Competing anions exerted minimal influence on biosorption efficiency, whereas adding glucose significantly enhanced Cr(VI) removal. The adsorption data were best described by the Langmuir isotherm model, indicating a monolayer binding of Cr(VI) onto the bacterial surface. The main functional groups involved in the biosorption process revealed by FTIR analysis are hydroxyl, phosphoryl, carboxyl, and amine groups in the binding of Cr(VI). SEM–EDX analysis also confirmed the association of chromium with the cell surface. These findings highlight the potential of S. aureus CC1956 as an effective biosorbent for Cr(VI) and its promising application in the bioremediation of contaminated wastewater.

Selenium biofortification of staple foods is a strategy for ameliorating Selenium deficiency among populations. The aim of this study is to investigate the effect of Selenium biofortification on some phytochemicals present in Gboma (Solanum macrocarpon L.) leaves and to assess the effect of its dietary inclusions on some antioxidant molecules, immunoglobulins and inflammatory cytokines in the serum of Wistar rats. Gboma, also called African Eggplant was cultivated on soil enriched with Selenium biofortified fertilizer and harvested at maturity. The phytochemicals present were assessed via HPLC. The samples were also included into the diet of Wistar rats (4% and 8% inclusions) for fourteen days. The serum was then collected and assayed for glutathione peroxidase (GPx), glutathione-S-transferase (GST) and catalase activities. Imuunoglobulins M, G, A and E as well as the inflammatory makers-tumor necrosis factor-α and interleukin-10 were also assayed for. The results showed that Selenium bioaccumulation increased the concentration of some phytochemicals such as chlorogenic acid, 4- hydroxybenzoic acid and delphinidin. An increase in the activity of the antioxidant enzymes was also observed in rats fed with Selenium biofortified Gboma leaves (4% and 8%), compared to control and rats fed diets supplemented with Gboma leaves without Selenium biofortification. In addition, IgG, IgM and IgA levels increased in the serum of treated rats, coupled with an increase in IL-10 levels. This study therefore, shows that Selenium biofortification enhanced the antioxidant and immunomodulatory properties of Gboma leaves.