Ferrozine Assay Research Articles

Antioxidant and Anti-Inflammatory Profiles of Two Mexican Heteropterys Species and Their Relevance for the Treatment of Mental Diseases: H. brachiata (L.) DC. and H. cotinifolia A. Juss. (Malpighiaceae).

Depression and anxiety are recognized as the most common mental diseases worldwide. New approaches have considered different therapeutic targets, such as oxidative stress and the inflammation process, due to their close association with the establishment and progression of mental diseases. In the present study, we evaluated the antioxidant and anti-inflammatory activities of the methanolic extracts of the plant species Heteropterys brachiata and Heteropterys cotinifolia and their main compounds, chlorogenic acid and rutin, as potential complementary therapeutic tools for the treatment of anxiety and depression, since the antidepressant and anxiolytic activities of these methanolic extracts have been shown previously. Additionally, we also evaluated their inhibitory activity on the enzyme acetylcholinesterase (AChE). Our results revealed that both species exhibited potent antioxidant activity (>90%) through the TBARS assay, while by means of the DPPH assay, only H. cotinifolia exerted potent antioxidant activity (>90%); additionally, low metal chelating activity (<40%) was detected for all samples tested in the ferrozine assay. The methanolic extracts of H. brachiata and H. cotinifolia exhibited significant anti-inflammatory activities in the TPA-induced ear edema, while only H. cotinifolia exerted significant anti-inflammatory activities in the MPO assay (>45%) and also exhibited a higher percentage of inhibition on AChE of even twice (>80%) as high as the control in concentrations of 100 and 1000 µg/mL. Thus, the potent antioxidant and inflammatory properties and the inhibition of AChE may be involved in the antidepressant activities of the species H. cotinifolia, which would be positioned as a candidate for study in drug development as an alternative in the treatment of depression.

Phlomis crinita Cav. From Algeria: A source of bioactive compounds possessing antioxidant and wound healing activities

Ethnopharmacological relevancePhlomis crinita Cav. (Lamiaceae), locally known as “El Khayata” or “Kayat El Adjarah”, is traditionally used in Algeria for its wound-healing properties. Aim of the studyInvestigate, for the first time, the phytochemical profile, safety, antioxidant and wound-healing activities of the flowering tops methanolic extract of P. crinita (PCME) collected from Bouira Province in the North of Algeria. Materials and methodsPreliminary phytochemical assays were carried out on PCME to quantify the main classes of bioactive compounds, such as total phenols, flavonoids, and tannins. An in-depth LC-DAD-ESI-MS analysis was carried out to elucidate the phytochemical profile of this plant species. Antioxidant activity was investigated by several colorimetric and fluorimetric assays (DPPH, TEAC, FRAP, ORAC, β-carotene bleaching and ferrozine assay). The acute oral toxicity of PCME (2000 mg/kg b.w.) was tested in vivo on Swiss albino mice, whereas the acute dermal toxicity and wound-healing properties of the PCME ointment (1–5% PCMO) were tested in vivo on Wistar albino rats. Biochemical and histological analyses were carried out on biological samples. ResultsThe phytochemical screening highlighted a high content of phenolic compounds (175.49 ± 0.8 mg of gallic acid equivalents/g of dry extract), mainly flavonoids (82.28 ± 0.44 mg of quercetin equivalents/g of dry extract). Fifty-seven compounds were identified by LC-DAD-ESI-MS analysis, belonging mainly to the class of flavones (32.27%), with luteolin 7-(6″-acetylglucoside) as the most abundant compound and phenolic acids (32.54%), with salvianolic acid C as the most abundant compound. A conspicuous presence of phenylethanoids (15.26%) was also found, of which the major constituent is forsythoside B. PCME showed a strong antioxidant activity with half-inhibitory activity (IC50) ranging from 1.88 to 37.88 μg/mL and a moderate iron chelating activity (IC50 327.44 μg/mL). PCME appears to be safe with Lethal Dose 50 (LD50) ≥ 2000 mg/kg b.w. No mortality or toxicity signs, including any statistically significant changes in body weight gain and relative organs’ weight with respect to the control group, were recorded. A significant (p < 0.001) wound contraction was observed in the 5% PCMO-treated group with respect to the untreated and petroleum jelly groups between 8 and 20 days, whereas no statistically significant results were observed at the two lower doses (1 and 2% PCMO). In addition, the 5% PCMO-treated group showed a statistically significant (p < 0.05) wound healing activity with respect to the reference drug-treated group, showing, at the end of the study, the highest wound contraction percentage (88.00 ± 0.16%). ConclusionPCME was safe and showed strong antioxidant and wound-healing properties, suggesting new interesting pharmaceutical applications for P. crinita based on its traditional use.

Metal‐chelating antioxidant peptides: Biosensor screening methods as alternatives to the ferrozine assay

AbstractPreventing metal‐catalyzed lipid oxidation in food products, which decreases nutritional value and sensory quality, is crucial in the food industry. This is typically achieved through the use of metal‐chelating molecules. While the ferrozine assay is widely used to screen protein hydrolysates for metal chelating activity, it has proven difficult to use with pure peptides. This study evaluates the potential of surface plasmon resonance (SPR) and electrically switchable nanolever technology (switchSENSE®) as alternative screening methods. Unfortunately, solubility issues and large standard deviations precluded a direct correlation between the ferrozine assay and these biosensor techniques. Both techniques, however, were able to quantitatively distinguish between two peptides with very similar sequences despite the absence of a correlation between dissociation constants determined by SPR and switchSENSE®. This study highlights the potential of SPR and switchSENSE® for screening the metal chelating activity of pure peptides, advancing the understanding of peptide‐metal ion interactions.

Iron overload promotes hemochromatosis-associated osteoarthritis via the mTORC1-p70S6K/4E-BP1 pathway

BackgroundsJoint iron overload in hemochromatosis induces M1 polarization in synovial macrophages, releasing pro-inflammatory factors and leading to osteoarthritis development. However, the mechanism by which iron overload regulates M1 polarization remains unclear. This study aims to elucidate the mechanism by which synovial iron overload promotes macrophage M1 polarization. MethodsIn vitro, RAW264.7 macrophages were treated with iron and divided into five groups based on the concentration of the iron chelator, desferrioxamine (DFO): Ctrl, Fe, DFO1, DFO2, and DFO3. In vivo, rats were categorized into five groups based on iron overload and intra-articular DFO injection: A-Ctrl, A-Fe, A-DFO1, A-DFO2, and A-DFO3. Osteoarthritis was induced by transecting the left knee anterior cruciate ligament. Macrophage morphology was observed; Prussian Blue staining quantified iron deposition in macrophages, synovium, and liver; serum iron concentration was measured using the ferrozine method; cartilage damage was assessed using H&E and Safranin O-Fast Green staining; qPCR detected iNOS and Arg-1 expression; Western Blot analyzed the protein expression of iNOS, Arg-1, 4E-BP1, phosphorylated 4E-BP1, p70S6K, and phosphorylated p70S6K; ELISA measured TNF-α and IL-6 concentrations in supernatants; and immunohistochemistry examined the protein expression of F4/80, iNOS, Arg-1, 4E-BP1, phosphorylated 4E-BP1, p70S6K, and phosphorylated p70S6K in the synovium. ResultsIn vitro, iron-treated macrophages exhibited Prussian Blue staining indicative of iron overload and morphological changes towards M1 polarization. qPCR and Western Blot revealed increased expression of the M1 polarization markers iNOS and its protein. ELISA showed elevated TNF-α and IL-6 levels in supernatants. In vivo, ferrozine assay indicated significantly increased serum iron concentrations in all groups except A-Ctrl; Prussian Blue staining showed increased liver iron deposition in all groups except A-Ctrl. Iron deposition in rat synovium decreased in a DFO concentration-dependent manner; immunohistochemistry showed a corresponding decrease in iNOS and phosphorylated 4E-BP1 expression, and an increase in Arg-1 expression. ConclusionIntracellular iron overload may exacerbate joint cartilage damage by promoting synovial macrophage M1 polarization through phosphorylation of 4E-BP1 in the mTORC1-p70S6K/4E-BP1 pathway.

Fe-Cr-Nb-B Magnetic Particles and Adipose-Derived Mesenchymal Cells Trigger Cancer Cell Apoptosis by Magneto-Mechanical Actuation.

Magnetic nanoparticles (MPs) are emerging as powerful and versatile tools for biotechnology, including cancer research and theranostic applications. Stem cell-mediated magnetic particle delivery has been previously recognized as a modality to target sites of malignancies. Here, we propose the use of adipose-derived mesenchymal cells (ADSC) for the targeted delivery of Fe-Cr-Nb-B magnetic particles to human osteosarcoma (HOS) cells and magneto-mechanical actuation (MMA) for targeting and destroying HOS cells. We show that MPs are easily incorporated by ADSCs and HOS cells, as confirmed by TEM images and a ferrozine assay. MP-loaded ADSCs display increased motility towards tumor cells compared with their unloaded counterparts. MMA of MP-loaded ADSCs induces HOS destruction, as confirmed by the MTT and live/dead assays. MMA enables the release of the MPs towards cancer cells, producing a significant decrease (about 80%) in HOS viability immediately after application. In contrast, normal human dermal fibroblasts' (NHDFs) viability exposed to similar conditions remains high, showing a differential behavior of normal and malignant cells to MP load and MMA exposure. Taken together, the method could derive successful strategies for in vivo applications in targeting and destroying malignant cells while protecting normal cells.

Chelating peptides from rapeseed meal protein hydrolysates: identification and evaluation of their capacity to inhibit lipid oxidation.

An optimized proteolysis process was applied to rapeseed meal proteins (RP) and the hydrolysate was separated by membrane filtration allowing the production of highly metal-chelating peptides in the permeate. In order to identify the chemical structure of the most active obtained metal-chelating peptides, immobilized metal affinity chromatography (IMAC) was applied. The RP-IMAC peptide fraction was mainly composed of small peptides from 2 to 20 amino acids. Using the Ferrozine assay, RP-IMAC peptides showed a significant chelating efficiency higher than sodium citrate and close to that of EDTA. The peptide sequences were identified by UHPLC-MS and several possible iron binding sites were found. β-carotene oxidation assay and lipid oxidation in bulk oils or emulsion were carried out to evaluate the potential of such peptides as efficient antioxidants to protect lipids from oxidation. While chelating peptides showed a limited efficiency in bulk oil, they performed more efficiently in emulsion.

Dihydromyricetin alleviates hippocampal ferroptosis in type 2 diabetic cognitive impairment rats via inhibiting the JNK-inflammatory factor pathway

Type 2 diabetes mellitus (T2DM) is frequently associated with diabetic cognitive impairment (DCI), and recent studies have shown a strong association between DCI and hippocampal ferroptosis. In this study, we administered dihydromyricetin (DHM) or JNK inhibitor SP600125, to T2DM rats and monitored changes in blood glucose levels, conducted behavioral tests, and detected changes in JNK, inflammatory factors and ferroptosis-related indicators. Our findings demonstrated that T2DM rats displayed signs of cognitive impairment (CI), with ferrozine assays indicating elevated iron content in the hippocampus. Concurrently, there was an increase in p-JNK activity and inflammatory factors IL-6 and TNF-α in the hippocampal region of these rats. Furthermore, we observed elevated levels of Fe2+, MDA, ROS, LPO, and ACSL4, along with a decrease in GPX4 and GSH, suggesting the occurrence of hippocampal ferroptosis. SP600125 application reversed these changes in the T2DM rats, although it exhibited no significant effects in the control group. Treatment with high and low doses of DHM led to a reduction in p-JNK expression, inflammatory factor-related proteins, and iron accumulation in the hippocampal region, effectively alleviating hippocampal ferroptosis in T2DM rats. No notable effects of DHM were observed in the control group. To conclude, our study suggests that DHM can potentially alleviate hippocampal ferroptosis of T2DM cognitive impairment rats, primarily by suppressing the JNK-inflammatory factor pathway in the hippocampus.

Acquiring Iron-Reducing Enrichment Cultures: Environments, Methods and Quality Assessments

Lateritic duricrusts cover iron ore deposits and form spatially restricted, unique canga ecosystems endangered by mining. Iron cycling, i.e., the dissolution and subsequent precipitation of iron, is able to restitute canga duricrusts, generating new habitats for endangered biota in post-mining landscapes. As iron-reducing bacteria can accelerate this iron cycling, we aim to retrieve microbial enrichment cultures suitable to mediate the large-scale restoration of cangas. For that, we collected water and sediment samples from the Carajás National Forest and cultivated the iron-reducing microorganisms therein using a specific medium. We measured the potential to reduce iron using ferrozine assays, growth rate and metabolic activity. Six out of seven enrichment cultures effectively reduced iron, showing that different environments harbor iron-reducing bacteria. The most promising enrichment cultures were obtained from environments with repeated flooding and drying cycles, i.e., periodically inundated grasslands and a plateau of an iron mining waste pile characterized by frequent soaking. Selected enrichment cultures contained iron-reducing and fermenting bacteria, such as Serratia and Enterobacter. We found higher iron-reducing potential in enrichment cultures with a higher cell density and microorganism diversity. The obtained enrichment cultures should be tested for canga restoration to generate benefits for biodiversity and contribute to more sustainable iron mining in the region.

Development of an Fe2+ sensing system based on the inner filter effect between upconverting nanoparticles and ferrozine.

The ferrozine (FZ) assay is a vital oxidation state-specific colorimetric assay for the quantification of Fe2+ ions in environmental samples due to its sharp increase in absorbance at 562 nm upon addition of Fe2+. However, it has yet to be applied to corresponding fluoresence assays which typically offer higher sensitivites and lower detection limits. In this article we present for the first time its pairing with upconverting luminescent nanomaterials to enable detection of Fe2+via the inner filter effect using a low-power continuous wave diode laser (45 mW). Upon near infra-red excitation at 980 nm, the overlap of the upconversion emission of Er3+ at approximately 545 nm and the absorbance of the FZ:Fe2+ complex at 562 nm enabled measurement in the change of UCNP emission response as a function of Fe2+ concentration in a ratiometric manner. We first applied large, ultra-bright poly(acrylic acid) (PAA)-capped Gd2O2S:Yb3+,Er3+ UCNPs upconverting nanoparticles (UCNPs) for the detection of Fe2+ using FZ as the acceptor. The probe displayed good selectivity and sensitivity for Fe2+, with a low limit of detection (LoD) of 2.74 μM. Analogous results employing smaller (31 nm) PAA-capped hexagonal-phase NaYF4:Yb3+,Er3+ UCNPs synthesised in our lab were achieved, with a lower LoD towards Fe2+ of 1.43 μM. These results illustrate how the ratiometric nature of the system means it is applicable over a range of particle sizes, brightnesses and nanoparticle host matrices. Preliminary investigations also found the probes capable of detecting micromolar concentrations of Fe2+ in turbid solutions.

Allium paradoxum extract mediated green synthesis of SeNPs: Assessment of their anticancer, antioxidant, iron chelating activities, and antimicrobial activities against fungi, ATCC bacterial strains, Leishmania parasite, and catalytic reduction of methylene blue

Allium paradoxum extract was used to make selenium nanoparticles (A-SeNPs). The morphological features showed the semi-spherical A-SeNPs with an average diameter of 37.5 nm from the TEM image. The EDX and XRD data confirmed the synthesis of A-SeNPs and FT-IR spectrum observed the importance of bio-functional group existing in A-Extract in the fabrication of A-SeNPs. Also, TG/DTA diagram proved the presence of capping agent on the surface of nanoparticles and the stability of these NPs. Furthermore, the efficiency of Methylene blue (MB) dye degradation obtained 100% for 50, 60, and 70 μl of A-SeNPs (700 μg/ml). The antioxidant activity of A-SeNPs (2.73–87.7 μg/ml) was assessed via DPPH radical scavenging assay, demonstrating an IC50 value of 92.55 ± 1.35 μg/ml. In the Ferrozine assay, A-SeNPs (1.33–41.66 μg/ml) showed potent iron chelation activity with an IC50 value of 24.8 ± 0.73 μg/ml. In the antibacterial investigation, A-SeNPs (0.17–175 μg/ml) demonstrated the highest activity against P. aeruginosa and A. baumannii. Besides, our nanoparticles had high antifungal activity against several fungi strains and also presented IC50 value of 35.49 μg/ml against promastigotes. A-SeNPs exhibited anticancer activity on MCF-7 and AGS cells with IC50 values of 33.97 and 22.33 μg/ml, respectively. Therefore, synthesized SeNPs presented high potential in various applications.

Extracellular electrons transferred from honey probiotic Bacillus circulans inhibits inflammatory acne vulgaris

Bacillus circulans (B. circulans) is widely used as an electrogenic bacterium in microbial fuel cell (MFC) technology. This study evaluated whether B. circulans can ferment glucose to generate electricity and mitigate the effects of human skin pathogens. The electricity production of B. circulans was examined by measuring the voltage difference and verified using a ferrozine assay in vitro. To investigate the fermentation effects of B. circulans on inhibition of human skin pathogens, Cutibacterium acnes (C. acnes) was injected intradermally into mice ears to induce an inflammatory response. The results revealed that the glucose–B. circulans co-culture enhanced electricity production and significantly supressed C. acnes growth. The addition of roseoflavin to inhibit flavin production considerably reduced the electrical energy generated by B. circulans through metabolism and, in vivo test, recovered C. acnes count and macrophage inflammatory protein 2 (MIP-2) levels. This suggests that B. circulans can generate electrons that affect the growth of C. acnes through flavin-mediated electron transfer and alleviate the resultant inflammatory response. Our findings demonstrate that probiotics separated from natural substances and antimicrobial methods of generating electrical energy through carbon source fermentation can help in the treatment of bacterial infections.

Potential of Shewanella Oneidensis as bioleaching agent in reducing Fe (III) to Fe (II) for gold extraction

Conventional method for gold extraction using cyanide is not environmentally friendly and harmful to the environment. Thus, we investigate the potential of Shewanella oneidensis as bioleaching agent for gold extraction to replace the cyanide leaching process. The concentration of Fe (II) was determined via Ferrozine Assay method using Spectrophotometer, while the concentration of gold (Au) was determined using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Some minerals such as pyrite, arsenopyrite, hematite, magnetite, and quartz were detected in the ore samples using XRD. The results show, S. oneidensis MR-1 was able to reduce Fe (III) to Fe (II) that can increase gold concentration. Gold concentrations were increased from 19 ppb to 28.5 ppb with 50% of percentage yield increased. In addition, the result shows hematite and magnetite in the samples was also reduced after bioleaching which might lead to the increasing amount of gold concentration. As a conclusion, S. oneidensis MR-1 was shown to be effective for bioleaching to improve gold extraction process.

Soluble, Colloidal, and Particulate Iron Across the Hydrothermal Vent Mixing Zones in Broken Spur and Rainbow, Mid-Atlantic Ridge.

The slow-spreading Mid-Atlantic Ridge (MAR) forms geological heterogeneity throughout the ridge system by deep crustal faults and their resultant tectonic valleys, which results in the existence of different types of hydrothermal vent fields. Therefore, investigating MAR hydrothermal systems opens a gate to understanding the concentration ranges of ecosystem-limiting metals emanating from compositionally distinct fluids for both near-field chemosynthetic ecosystems and far-field transport into the ocean interiors. Here, we present novel data regarding onboard measured, size-fractionated soluble, colloidal, and particulate iron concentrations from the 2018 R/V L’Atalante – ROV Victor research expedition, during which samples were taken from the mixing zone of black smokers using a ROV-assisted plume sampling. Iron size fractionation (<20, 20–200, and >200nm) data were obtained from onboard sequential filtering, followed by measurement via ferrozine assay and spectrophotometric detection at 562nm. Our results showed the persistent presence of a nanoparticulate/colloidal phase (retained within 20–200nm filtrates) even in high-temperature samples. A significant fraction of this phase was retrievable only under treatment with HNO3 – a strong acid known to attack and dissolve pyrite nanocrystals. Upon mixing with colder bottom waters and removal of iron in the higher parts of the buoyant plume, the larger size fractions became dominant as the total iron levels decreased, but it was still possible to detect significant (micromolar) levels of nanoparticulate Fe even in samples collected 5m above the orifice in the rising plume. The coolest sample (<10°C) still contained more than 1μM of only nitric acid-leachable nanoparticle/colloidal, at least 200 times higher than a typical Fe concentration in the non-buoyant plume. Our results support previous reports of dissolved Fe in MAR vent plumes, and we propose that this recalcitrant Fe pool – surviving immediate precipitation – contributes to maintaining high hydrothermal iron fluxes to the deep ocean.

Isolation and Chelation Activity of Plant Phenolic Root Exudates As Potential Clinical Iron Chelators

Introduction:Hemoglobinopathies such as β-Thalassemia (Thal) and other genetic disorders such as neurodegeneration with brain iron accumulation have complications of iron overload, which can impair vital processes such as cardiac and neurological function. In Thal, ineffective erythropoiesis leads to elevated gastrointestinal iron absorption and in severe cases may necessitate blood transfusions exacerbating the condition. Iron chelating agents such as deferoxamine (DFO), deferiprone, and deferasirox must be used, but can have unwanted side effects. While effective in treating iron overload, the increased risk of side effects at higher doses highlights the importance of finding new potent iron-chelating agents, either as replacements or as adjuvants. Plant based treatments may be better tolerated by patients, offering an alternative therapeutic approach. Plant secondary metabolites secreted from roots under iron limiting conditions may provide a novel source for this bioactivity. Plants rich in phenolic compounds and those tolerating alkaline soils, which necessitate efficient mobilization of soil-precipitated iron, are our focus here. The aim of this project is to functionally and analytically characterize naturally occurring plant root exudates as possible clinical iron chelators.Methods : We cultivated Populus trichocarpa ( Poplar), Thuja plicata (Western red-cedar), and Lavendula X intermedia (Lavender) cuttings under iron normal and iron limiting conditions. From their roots, exudates were isolated to characterize and determine their effectiveness as iron chelators. Total phenolic concentrations of exudates were evaluated using Folin-Ciocalteu reagent. The ferrozine assay was used as a competition assay to characterize total iron binding ability of root exudates and standard chelators, which was sensitive enough to differentiate chelation effectiveness between DFO, EDTA, and isolated root exudates at 800 nM. Furthermore, known plant iron chelators chlorogenic acid (CA), a phenolic, and the more lipophilic β-thujaplicin (hinokitiol) were compared to DFO, then used tomodel root exudates in a cell culture bioassay. The bioassay was developed using monocytic THP-1 cells (as an RE system model) to quantify intra- and extracellular iron, comparing iron uptake in cells exposed to varying concentrations of iron chelators as a way of evaluating chelation strengths of crude root exudates, β-thujaplicin, and CA in comparison to DFO.Results:Total phenolic production in P. trichocarpa root exudates increased significantly (p < 0.05) in response to iron depletion after 12 hrs. Iron binding ability increased almost four-fold upon iron depletion. In the ferrozine competition assay, iron depleted root exudates inhibited iron binding by 15% whereas iron normal exudates inhibited by only 4%. Iron binding of root exudates was similar to EDTA (13% inhibition) and about half that of DFO (30% inhibition). In the THP-1 cell bioassay, DFO and CA showed comparable trends of chelation activity. Cells exposed to either 50 or 100 μM CA or DFO reduced intracellular iron by at least 47% or 89%, respectively. However, at 50 and 100 µM β-thujaplicin increased iron uptake by 82 to 86% respectively. Further testing of plant root exudates is ongoing.Conclusions: Exposing P. trichocarpa to an iron deficient environment resulted in plants that secreted root exudates with significantly higher level of phenolics and increased iron chelation ability. This was shown in the ferrozine competition assay where iron depleted root exudates showed higher binding affinity for iron when compared to the iron normal exudates resulting in an iron chelation ability similar to the known iron chelator EDTA. In the bioassay using THP-1 monocytic cells, testing the plant phenolic CA, there was reduction of intracellular iron comparable to DFO, whereas the lipophilic chelator β-thujaplicin increased cellular iron. Consequently, chelators such as CA exclude iron from being taken up by the cells, while more lipophilic chelators, like β-thujaplicin enable transport through membranes, and thus have the capacity to transport iron both into and out of cells. Thus, we have shown that plant root exudates can yield potential iron chelators and that in general plant phenolics have iron chelation capacity comparable to the classic iron chelator DFO. DisclosuresWalter:Apopharma: Research Funding.

Electricity-producing Staphylococcus epidermidis counteracts Cutibacterium acnes

Staphylococcus epidermidis (S. epidermidis) ATCC 12228 was incubated with 2% polyethylene glycol (PEG)-8 Laurate to yield electricity which was measured by a voltage difference between electrodes. Production of electron was validated by a Ferrozine assay. The anti-Cutibacterium acnes (C. acnes) activity of electrogenic S. epidermidis was assessed in vitro and in vivo. The voltage change (~ 4.4 mV) reached a peak 60 min after pipetting S. epidermidis plus 2% PEG-8 Laurate onto anodes. The electricity produced by S. epidermidis caused significant growth attenuation and cell lysis of C. acnes. Intradermal injection of C. acnes and S. epidermidis plus PEG-8 Laurate into the mouse ear considerably suppressed the growth of C. acnes. This suppressive effect was noticeably reversed when cyclophilin A of S. epidermidis was inhibited, indicating the essential role of cyclophilin A in electricity production of S. epidermidis against C. acnes. In summary, we demonstrate for the first time that skin S. epidermidis, in the presence of PEG-8 Laurate, can mediate cyclophilin A to elicit an electrical current that has anti-C. acnes effects. Electricity generated by S. epidermidis may confer immediate innate immunity in acne lesions to rein in the overgrowth of C. acnes at the onset of acne vulgaris.

Reduction of Dissolved Fe(III) by As(V)-tolerant Bacteria Isolated from Rhizosphere Soil

BACKGROUND: Biological iron redox transformation alters iron minerals, which may act as effective adsorbents for arsenate [As(V)] in the environments. In the viewpoint of alleviating arsenate, microbial Fe(III) reduction was sought under high concentration of As(V). In this study, Fe(III)-reducing bacteria were isolated from the wild plant rhizosphere soils collected at abandoned mine areas, which showed tolerance to high concentration of As(V), in pursuit of potential agents for As(V) bioremediation. METHODS AND RESULTS: Bacterial isolation was performed by a series of enrichment, transfer, and dilutions. Among the isolated strains, two strains (JSAR-1 and JSAR-3) with abilities of tolerance to 10 mM As(V) and Fe(III) reduction were selected. Phylogenetic analysis using 16S rRNA genesequences indicated the closest members of Pseudomonas stutzeri DSM 5190 and Paenibacillus selenii W126, respectively for JSAR-1 and JSAR-3. Ferric and ferrous iron concentrations were measured by ferrozine assay, and arsenic concentration was analyzed by ICP-AES, suggesting inability of As(V) reduction whereas ability of Fe(III) reduction. CONCLUSION: Fe(III)-reducing bacteria isolated from the enrichments with arsenate and ferric iron were found to be resistant to a high concentration of As(III) at 10 mM. We suppose that those kinds of microorganisms may suggest good application potentials for As(V) bioremediation, since the bacteria can transform Fe while surviving under As-contaminated environments. The isolated Fe(III)-reducing bacterial strains could contribute to transformations of iron minerals which may act as effective adsorbents for arsenate, and therefore contribute to As(V) immobilization

X-ray Dose-Enhancing Impact of Functionalized Au-Fe3O4 Nanoheterodimers on MCF-7 and A549 Multicellular Tumor Spheroids.

The efficiency of nanoparticle-enhanced radiotherapy was studied by loading MCF-7 and A549 multicellular tumor spheroids (MCTSs) with caffeic acid- and nitrosonium-functionalized Au-Fe3O4 nanoheterodimers (Au-Fe3O4 NHDs). Transmission electron microscope images of MCTS cross-sectional sections visualized the invasion and distribution of the nitrosonium- and caffeic acid-functionalized Au-Fe3O4 NHDs (NO- and CA-NHDs) in the A549 and MCF-7 MCTSs, whereas the iron content of the MCTSs were quantified using the ferrozine assay. The synergistic impact of intracellular NO- and CA-NHDs and X-ray irradiation on the growth dynamics of the A549 and MCF-7 MCTSs was surveyed by monitoring their temporal evolution under a light microscope over a period of 14 days. The emergence of hypoxia during the spheroid growth was followed by detecting the lactate efflux of MCTSs without and with NO- and CA-NHDs. The performance of the NO- and CA-NHDs as X-ray dose-enhancing agents in the A549 and MCF-7 MCTSs was clarified by performing clonogenic cell survival assays and determining the respective dose-modifying factors for X-ray doses of 0, 2, 4, and 6 Gy. The NO- and CA-NHDs were shown to perform as potent X-ray dose-enhancing agents in A549 and MCF-7 MCTSs. Moreover, the CA-NHDs boosted their radio-sensitizing efficacy by inhibiting the lactate efflux as impairing metabolic reprogramming. A synergistic effect on the MCTS destruction was observed for the combination of both NHDs since the surfactants differ in their antitumor effect.

Comparative Antioxidant potential of two drought resistant medicinal plants of Rajasthan: Prosopis cineraria and Capparis decidua

The aim of this study was to assess and compare the antioxidant potential and total phenolic content of ethanolic and aqueous extracts of the fruits of Prosopis cineraria and Capparis decidua. Free radical scavenging activity of the extracts in the concentration range 0.5–40.0 mg/cm3 was determined by DPPH (2.2-diphenyl-1-picrylhydrazyl) assay using BHT as a standard. IC50 values for the ethanolic and aq. extracts of P. cineraria (7.026 ± 0.088 mg/cm3 and 4.097 ± 0.033 mg/cm3) were found to be significantly (p ≤ 0.05) lower than the corresponding extracts of C. decidua (47.538 ± 0.040 mg/cm3 and 14.066 ± 0.039 mg/cm3). Total phenolic content for the aq. extract of P. cineraria (3.512 ± 0.013 mg GAE/g) was significantly (p ≤ 0.05) higher than aq. extract of C.decidua (2.142 ± 0.032 mg GAE/g), whereas the ethanolic extracts of the two plants did not show any significant difference in their phenolic content. The FRAP value for the aq. extract of P. cineraria (17.951 ± 0.026 mg Fe(II) eqv/g) and C. decidua (21.343 ± 0.009 mg Fe(II) eqv/g) was significantly (p ≤ 0.05) higher than their corresponding ethanolic extracts (2.742 ± 0.023 and 2.313 ± 0.020 mg Fe (II) eqv/g). The reducing capacity by ferrozine assay for the ethanolic and aq. extracts of P. cineraria (4.767 ± 0.4877 and 10.370 ± 0.005 mg AE/g) were significantly (p ≤ 0.05) higher as compared to the ethanolic and aqueous extracts of C. decidua (0.160 ± 0.136 and 1.537 ± 0.046 mg AE/g).

Increasing Intracellular Levels of Iron with Ferric Ammonium Citrate Leads to Reduced P-glycoprotein Expression in Human Immortalised Brain Microvascular Endothelial Cells.

P-glycoprotein (P-gp) at the blood-brain barrier (BBB) precludes the brain penetration of many xenobiotics and mediates brain-to-blood clearance of β-amyloid, which accumulates in the Alzheimer's disease (AD) brain. Zinc and copper are reported to modulate BBB expression and function of P-gp; however, the impact of exogenous iron, which accumulates in AD, on P-gp dynamics remains unknown. P-gp protein and MDR1 transcript levels were assessed in immortalised human cerebral microvascular endothelial (hCMEC/D3) cells treated with ferric ammonium citrate (FAC; 250μM, 72h), by Western blotting and RT-qPCR, respectively. P-gp function was assessed using rhodamine-123 and [3H]-digoxin accumulation. Intracellular reactive oxygen species (ROS) levels were determined using 2',7'-dichlorofluorescin diacetate and intracellular iron levels quantified using a ferrozine assay. FAC treatment significantly reduced P-gp protein (36%) and MDR1 mRNA (16%) levels, with no significant change in rhodamine-123 or [3H]-digoxin accumulation. While P-gp/MDR1 downregulation was associated with elevated ROS and intracellular iron, MDR1 downregulation was not attenuated with the antioxidant N-acetylcysteine nor the iron chelators desferrioxamine and deferiprone, suggesting the involvement of a ROS-independent mechanism or incomplete iron chelation. These studies demonstrate that iron negatively regulates P-gp expression at the BBB, potentially impacting CNS drug delivery and brain β-amyloid clearance.

Facile approach to the solid support photografting coating of citric acid as a novel biomimetic iron chelator film

Herein, the facile photografting coating method was used to develop a novel metal biochelator film by covalent immobilization of citric acid (CA) onto polypropylene (PP) surface. First, PP film underwent a surface modification by UV-grafting of glycidyl methacrylate (GMA) in the presence of benzophenone (BP). The concentrations of GMA (bifunctional monomer) and BP (photoinitiator) were appropriately optimized to achieve the breath-figure-array structure and brush-like grafting configuration with a high availability of the reactive oxirane ring. Subsequently, CA was immobilized onto the PP-g-GMA surface via the ring-opening reaction to obtain the biochelator film (PP-g-GMA-g-CA). Fourier-transform infrared spectroscopy and solid state 13C nuclear magnetic resonance spectroscopy elucidated the chemical structure and grafting mechanism of grafted samples. X-ray photoelectron spectroscopy was used to detect the chemical composition of the surface of the grafted samples, by which the grafting density was relatively estimated. In addition, the uniformity of the grafting pattern and morphology of the grafting unit were observed using scanning electron microscopy and atomic force microscopy. Furthermore, the carboxylic acid density of the biochelator film (PP-g-GMA-g-CA) was quantified using a toluidine blue O assay, in which approximately 327 ± 58 nM carboxylic acid was detected per each film. The metal chelating activity of the film was also investigated using the colorimetric ferrozine assay, by which PP-g-GMA-g-CA film chelated approximately 215 ± 11 nM of Fe3+. Therefore, this newly developed system can be used as a versatile metal biochelator in a wide range of biomedical, cosmetic, and packaging applications.11Citric acid (CA), benzophenone (BP), glycidyl methacrylate (GMA), Fourier-transform infrared spectroscopy (FTIR), 13C nuclear magnetic resonance (13C NMR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), atomic force microscopy (AFM), polypropylene (PP), toluidine blue O (TBO), breath figure array (BFA)