Ammonium Pyrrolidine Dithiocarbamate Research Articles

ROLE OF NF-κB TRANSCRIPTION FACTOR ACTIVATION IN THE PROCESSES OF CONNECTIVE TISSUE COMPONENTS DEGRADATION IN SKELETAL MUSCLES UNDER METABOLIC SYNDROME

Connective tissue, encompassing both cellular and non-cellular elements, plays an important role in the progression of numerous pathological processes across various organs and tissues. Within skeletal muscle tissue, the extracellular matrix not only plays a structural and supporting function, but it is a complex multicomponent system that performs a number of regulatory functions. At present, the effect of activation of the transcription factor NF-κB on the quantitative and qualitative composition of the components of the extracellular matrix in skeletal muscles under metabolic syndrome development is insufficiently studied. The aim of this work is to study the effect of ammonium pyrrolidinedithiocarbamate on the concentration of glycosaminoglycans, the concentration of individual fractions of glycosaminoglycans, the content of free L-oxyproline and sialic acids in the biceps femoris muscle of rats under metabolic syndrome. The study was conducted on 24 male Wistar rats weighing 200-260 g, which were randomly divided into 4 groups of 6 animals each. The first was control; the second made up the metabolic syndrome modeling group. Metabolic syndrome was reproduced by adding a 20% fructose solution to the standard vivarium diet as the only source of drinking water. Metabolic syndrome was modelled for 60 days. The third group received ammonium pyrrolidinedithiocarbamate administration at a dose of 76 mg/kg intraperitoneally (i/p) three times a week for 60 days. The fourth group underwent combined treatment involving the administration of both ammonium pyrrolidinedithiocarbamate and metabolic syndrome modeling. In a 10% homogenate of the biceps femoris muscle, the total concentration of glycosaminoglycans, the concentration of the heparin-heparan fraction of glycosaminoglycans, the keratan-dermatan fraction of glycosaminoglycans, the chondroitin fraction of glycosaminoglycans, and the content of free L-oxyproline and sialic acids were assessed. The introduction of ammonium pyrrolidinedithiocarbamate under metabolic syndrome modelling led to a decrease in the total concentration of glycosaminoglycans by 9.2% compared to the metabolic syndrome group. Under these conditions, the concentration of the heparin-heparan fraction increased by 121.1%, the keratan-dermatan fraction decreased by 32.8%, and the concentration of the chondroitin fraction decreased by 38.7% compared to the metabolic syndrome group. The concentration of free L-oxyproline and sialic acids in the biceps femoris muscle decreased by 19.8% and 24.4%, respectively, compared to the metabolic syndrome group. Blockade of activation of the transcription factor NF-κB by intraperitoneal administration of ammonium pyrrolidinedithiocarbamate against the background of metabolic syndrome modelling leads to a decrease in the depolymerization of glycoproteins and proteoglycans, reduces the intensity of collagenolysis and leads to a redistribution of concentrations of individual fractions of glycosaminoglycans, characterized by an increase in the content of the heparin-heparan fraction and a decrease in chondroitin and keratan-dermatan fractions in the biceps femoris muscle of rats.

A green flow-batch liquid phase microextraction lab-in-syringe platform based on natural deep eutectic solvents for toxic metal determination

In this work, a novel functional and reliable computer-controlled flow-batch lab-in-syringe (LIS) platform was developed for liquid phase microextraction (LPME) based on the use of natural deep eutectic solvents (NADES) as green alternatives to conventional extractants. The proposed automatic on-line LIS system is reported for the first time and demonstrated for the determination of toxic metals in aqueous samples, as a front-end to flame atomic absorption spectrometry (FAAS). To the best of our knowledge, the determination of metals by atomic spectrometric techniques processing a LIS preconcentration system using NADES has not been previously reported. The analytical process included the in-syringe metal complexation of Cd, Cu, and Pb (model analytes) with ammonium pyrrolidine dithiocarbamate and the subsequent microextraction of the resulted complexes by a mixture of menthol:heptanoic acid at a molar ratio of 1:2. After phase separation, the NADES was transferred towards the flame for direct atomization in an automatic and precise manner. The main attributes that affect the performance of the method were thoroughly studied. Under optimum conditions, the limits of detection ranged between 0.54 and 4.52 μg L−1 corresponding to a sample consumption of 4000 μL. The relative standard deviations were less than 3.8% demonstrating good method precision. As a proof-of-concept, the developed system was used for the analysis of drinking and environmental water samples resulting in good relative recoveries (i.e., 94.0–104.0%). The green character and the applicability of the proposed approach were demonstrated by the Green Analytical Procedure Index (GAPI), and Blue Applicability Grade Index (BAGI), respectively.

IMPACT OF NF-κB AND NRF2 TRANSCRIPTION FACTOR MODULATORS ON METABOLIC CHARACTERISTICS IN MANDIBLE BONES OF RATS DURING RECOVERY FROM INCOMPLETE FRACTURE UNDER CHRONIC ALCOHOL INTOXICATION

This study aims at investigating the influence of specific modulators of NF-κB and Nrf2 transcription factors on oxidative-nitrosative stress indicators and bone biopolymer depolymerization in mandibular bone following incomplete fracture under chronic alcohol intoxication (CAI). Twenty-eight white male Wistar rats were divided into five groups: Group 1 comprised "falsely injured" rats, while Group 2 underwent incomplete mandibular fracture (IMF) under CAI exposure. Rats in groups 3 and 4 received intraperitoneal injections of ammonium pyrrolidinium dithiocarbamate, an inhibitor of NF-κB activation, in a dose of 76 mg/kg, and dimethyl fumarate, an Nrf2 inducer, in a dose of 15 mg/kg three times a week for 14 days following the modeling of IMF under CAI exposure. The activity of total NO synthase, including its constitutive and inducible isoforms, along with ornithine decarboxylase, and concentrations of peroxynitrites of alkaline and alkaline-earth metals, free hydroxyproline, N-acetylneuraminic, and hexuronic acids were assessed in the homogenate of the standard mandible area using a spectrophotometric method. The findings have demonstrated that the administration of ammonium pyrrolidine dithiocarbamate and dimethyl fumarate notably decreased the activity of NO synthase (primarily its inducible isoform) and the concentration of peroxynitrite in the mandibular bone homogenate, while increasing the activity of ornithine decarboxylase, a key enzyme in polyamine biosynthesis. Furthermore, under experimental conditions, the use of ammonium pyrrolidine dithiocarbamate and dimethyl fumarate limited the depolymerization of bone biopolymers (collagen, glycoproteins, and proteoglycans), thereby facilitating effective reparative osteogenesis.

EFFECT OF AMMONIUM PYRROLIDINEDITHIOCARBAMATE ON THE DEVELOPMENT OF OXIDATIVE STRESS IN BICEPS FEMORIS MUSCLES OF RATS DURING MODELLED METABOLIC SYNDROME

Excessive consumption of high-calorie food, a sedentary lifestyle and increased psycho-emotional stress are risk factors for the development of metabolic syndrome. These factors are especially relevant for residents of countries with highly developed economies. Metabolic syndrome is accompanied not only by metabolic disorders, but also leads to the development of a systemic inflammatory response, which is associated with excessive production and circulation of cytokines in the blood. As a rule, the activation of the transcription factor NF-κB leads to an increase in the production of pro-inflammatory cytokines.
 The aim of this work is to determine the effect of the NF-κB transcription factor activation inhibitor on the activity of antioxidant enzymes, the production of superoxide anion radical, the content of oxidatively modified proteins, and the concentration of malondialdehyde in the biceps femoris muscle of rats who underwent experimental metabolic syndrome.
 The study included 24 sexually mature male Wistar rats weighing 200-260 g. The animals were divided into 4 groups of 6 animals each. The first group was the control group; the second group involved the rats exposed to metabolic syndrome simulated by adding a 20% fructose solution as the only source of drinking water to the standard vivarium diet for 60 days; the third group involved the animals received ammonium pyrrolidine dithiocarbamate in a dose of 76 mg/kg intraperitoneally 3 times a week for 60 days; the fourth group was exposed to the combined effect of the ammonium pyrrolidinedithiocarbamate administration during modeled metabolic syndrome. In this study we investigated a 10% homogenate of the biceps femoris muscle with the research focus on several parameters: superoxide anion radical production, superoxide dismutase and catalase activity, malondialdehyde concentration, and the presence of oxidatively modified proteins.
 Simulation of the metabolic syndrome led to the development of oxidative stress in the biceps muscle of rats that was accompanied by an increase in the production of the superoxide anion radical and a decrease in the activity of antioxidant enzymes. The administration of ammonium pyrrolidinedithiocarbamate during modeled metabolic syndrome caused a decrease in the basic production of superoxide anion radical, production of superoxide anion radical by the microsomal electron transport chain and production of superoxide anion radical by the mitochondrial electron transport chain by 30.28%, 26.21 %, and 27.00%, respectively, compared to the rats in metabolic syndrome group. Superoxide dismutase activity increased by 78.81% and catalase activity grew by 144.74% compared to the metabolic syndrome group. The concentration of free malondialdehyde under the administration of ammonium pyrrolidinedithiocarbamate during metabolic syndrome reduced by 51.80%, and the content of oxidatively modified proteins decreased by 31.74% compared to the metabolic syndrome group.
 The administration of ammonium pyrrolidinedithiocarbamate, an NF-κB transcription factor activation inhibitor, effectively prevents the development of oxidative stress in the biceps femoris muscle of rats with modeled metabolic syndrome.
 This study is a part of the initiative research project No. 0124U000092 "High- and low-intensity phenotypes of systemic inflammatory response: molecular mechanisms and new medical technologies for their prevention and correction".

ANALYSIS OF SOME HEAVY METALS LEVEL IN ISPARTA'S DRINKING WATER USING UV SPECTROPHOTOMETRY AND PRINCIPAL COMPONENT REGRESSION

Background: Heavy metals, which are likely to be found in natural water samples, can cause some discomfort when taken into the body in high amounts. The aim of this study is to create complexes of iron, copper and cadmium, which are major heavy metals that can be found in natural water samples, with ammonium pyrrolidine dithiocarbamate (APDC) chelate, to analyze these complexes with UV-Spectrophotometry after the optimum conditions to be created in water samples, and to apply the principal component regression chemometric method to the data obtained here. Method: In the applied spectrophotometric method, complexes of each heavy metal were first formed with APDC. Then, appropriate mixtures of these complexes were prepared and their spectra were recorded. Principal component regression chemometric method was applied to the data obtained. Results: Very consistent results of the chemometric method applied to the data obtained in the spectrophotometric analysis of the complexes of the heavy metals studied after providing optimum conditions were observed. Conclusion: It can be stated that the method developed in the research and the chemometric method applied to the data obtained from here can be easily applied in routine water analysis. Peer Review History: Received 10 December 2023; Revised 29 January 2024; Accepted 3 March; Available online 15 March 2024 Academic Editor: Dr. Emmanuel O. Olorunsola, Department of Pharmaceutics & Pharmaceutical Technology, University of Uyo, Nigeria, olorunsolaeo@yahoo.com Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 7.0/10 Reviewers: Dr. Dennis Amaechi, MrsFoluBabade Mini Estate , Flat 5 by Old Soldiers Quarter, Sabongari/Bwari, Abuja- Federal Capital Territory, Nigeria. amaechitoexcel@yahoo.com Dr. Wafa Mohamed Al Madhagi, Sana’a University, Yemen, walmadhaji1983@gmail.com Prof. Cyprian Ogbonna ONYEJI, Obafemi Awolowo University, Ile-Ife, Nigeria, conyeji@oauife.edu.ng

ISFME extraction of As species from some real water samples using an imidazolium-based task-specific ionic liquid (TSIL): Synthesis and characterization

ABSTRACT To determine of arsenic species in real water samples using electrothermal atomic absorption spectrometry, a high-performance in-situ solvent formation microextraction technique has been developed using homogenous liquid – liquid microextraction concepts. The developed method was based on the use of a synthesized imidazolium-based ionic liquid (IL) modified with ammonium pyrrolidine dithiocarbamate as a task-specific ionic liquid (TSIL), which was chelated with As(III) and then converted to a hydrophobic IL using ammonium hexafluorophosphate in anion exchange reactions. As(V) was reduced to As(III), using a satisfied reducing agent, and the total amount of As was analyzed using ETAAS. TSIL acts simultaneously as an extracting solvent and a chelating agent. The characterization of the synthesized TSIL was performed using13CNMR and FTIR analyses. When optimal conditions were met, linear dynamic ranges of 0.5–50 µg/L and 0.5–20 µg/L were obtained in the determination of As(III) and total As, respectively. The limits of detection (LOD) and quantitation (LOQ) were determined to be 0.021 µg/Land 0.064 µg/L for the determination of As(III) (for concentration 20 µg/L), respectively, and the standard deviation (RSD%, n = 7) was 2.0%. To evaluate the validity of the method, it was successfully applied for As species determination in different real water samples.

An “off-on” fluorescent nanosensor for the detection of cadmium ions based on APDC-etched CdTe/CdS/SiO2 quantum dots

In this study, we have developed a novel fluorescent "OFF-ON" quantum dots (QDs) sensor based on CdTe/CdS/SiO2 cores. Ammonium pyrrolidine dithiocarbamate (APDC), ethylenediamine tetraacetic acid (EDTA), and 1,10-phenanthroline (Phen) served as potential chemical etchants. Among these three etchants, APDC exhibited the most pronounced quenching effect (94.06%). The APDC-etched CdTe/CdS/SiO2 QDs demonstrated excellent optical properties: the fluorescence of the APDC-etched CdTe/CdS/SiO2 QDs system (excitation wavelength: 365 nm and emission wavelength: 622 nm) was significantly and selectively restored upon the addition of cadmium ions (Cd2+) (89.22%), compared to 15 other metal ions. The linear response of the APDC-etched CdTe/CdS/SiO2 QDs was observed within the cadmium ion (Cd2+) concentration ranges of 0–20 μmol L−1 and 20–160 μmol L−1 under optimized conditions (APDC: 300 μmol L−1, pH: 7.0, reaction time: 10 min). The detection limit (LOD) of the APDC-etched CdTe/CdS/SiO2 QDs for Cd2+ was 0.3451 μmol L−1 in the range of 0–20 μmol L−1. The LOD achieved by the QDs in this study surpasses that of the majority of previously reported nanomaterials. The feasibility of using APDC-etched CdTe/CdS/SiO2 QDs for Cd2+ detection in seawater, freshwater, and milk samples was verified, with average recoveries of 95.27%–110.68%, 92%–106.47%, and 90.73%–111.60%, respectively, demonstrating satisfactory analytical precision (RSD ≤ 8.26).

Bionanomaterial composed of Bradyrhizobium japonicum and graphene oxide for determination of mercury in water and fruit juice samples

In the present work, the synthesis of a novel hybrid bionanomaterial formed by the bacteria Bradyrhizobium japonicum (BJ) and the graphene oxide (GO) nanomaterial implemented in the miniaturized dispersive microsolid phase extraction technique (D-μ-SPE) was reported for the first time for the preconcentration and determination of Hg in water and fruit juice samples after a multivariate optimization. Selective Hg extraction was achieved by forming a complex with ammonium pyrrolidinedithiocarbamate (APDC) reagent and a multivariate study was performed to optimize the experimental conditions. The optimal Hg extraction conditions for 25 mL of sample were 3 mg of BJ@GO, NaNO3 at 1% (w/v), 6 min of vortex agitation and 9 min of centrifugation. For back extraction, 500 µL of 14 mol L−1 HNO3, 6 min of vortex agitation and 6 min of centrifugation were used followed by detection by cold vapor atomic fluorescence spectrophotometry (CV-AFS). Under optimized experimental conditions, an extraction efficiency of 98%, a detection limit of 0.08 µg L−1, a relative standard deviation of 3.5% (at 1 µg L−1 of Hg, n = 10), and a linear range of 0.26 - 4.0 µg L−1 were obtained. In addition, the sustainability of the method developed through the use of the Analytical GREEnness calculator (AGREE) software was evaluated, obtaining a greenness degree of 0.59. This work reports the first application of BJ@GO along with the D-μ-SPE technique for trace Hg determination water and fruit juice samples. In this way, this research work allows the exact and precise determination of low Hg concentrations in water and juice samples, which allows the evaluation of the contamination degree by this toxic metal in beverages widely consumed by the population.

A flow-batch lab-in-syringe foam microextraction platform for the simultaneous preconcentration and in situ membraneless gas-liquid separation of mercury prior to cold vapor atomic absorption spectrometry

Herein, the proof-of-concept of a novel lab-in-syringe (LIS) foam microextraction platform is presented as a front-end to cold vapor atomic absorption spectrometry (CVAAS) for the simultaneous preconcentration and membraneless gas-liquid separation (GLS) of inorganic mercury in biological samples. The proposed method is based on the on-line formation of the ammonium pyrrolidine dithiocarbamate complex with mercury that was retained in the pores of polyurethane foam immobilized on the piston of the LIS system. Metal complex elution and in situ mercury vapor generation are accomplished inside the microsyringe in a flow-batch format, while the separation of vapor species is achieved via the membraneless GLS found at the top of the syringe’s barrel. Under optimized operation conditions, for 90 s preconcentration time, the limit of detection was 0.02 μg L−1 and the repeatability (RSD) was 3.8% (at the 0.5 μg L−1 concentration level), within a working range extending up to 4.0 μg L−1. The practicality of the novel manifold was demonstrated using the Blue Applicability Grade Index, while the accuracy of the method was evaluated using certified reference materials and spiked samples.

Speciation of Chromium by Magnetic Solid Phase Microextraction Using an Activated Charcoal-Molybdenum (IV) Selenide-Magnetite Composite with Flame Atomic Absorption Spectrometric (FAAS) Detection

A simple and sensitive magnetic solid phase extraction (MSPE) method was developed for the separation-preconcentration and speciation of Cr in water samples. The system is based on the adsorption of Cr (VI)-ammonium pyrrolidinedithiocarbamate (APDC) complex on the activated charcoal@MoSe2@Fe3O4 composite. Total chromium has also been determined after the conversion of Cr (III) to Cr (VI) by oxidation with KMnO4. Cr (III) was determined as the difference between the total content of the Cr and Cr (VI). For quantitative recoveries, the effects of solution pH, adsorbent amount, volume of the sample, ligand volume, eluent type, and volume and effect of foreign ions were investigated. The limit of detection and limit of quantification for Cr was 0.36 ng mL−1 and 1.19 ng mL−1, respectively. The procedure was applied for the determination and speciation of chromium in water samples.

A continuous flow polyurethane foam solid phase microextraction lab-in-syringe platform for the automatic determination of toxic metals

A novel fully automatic continuous flow polyurethane foam solid phase microextraction lab-in-syringe system for on-line sample preconcentration/separation has been developed as a front-end to flame atomic absorption spectrometry. For the first time lab-in-syringe in continuous flow has been adopted for the determination of toxic metals. The microextraction procedure was performed after on-line metal complexation with ammonium pyrrolidine dithiocarbamate, while the elution was conducted by 400 μL of methyl isobutyl ketone. The main chemical and hydrodynamic factors that affected the performance of the method were optimized using Cd and Pb as model analytes. For 90 s preconcentration time, the limits of the detection were 0.20 and 1.7 μg L−1 for Cd and Pb, respectively, while the enhancement factors were 79 for Cd and 150 for Pb. The relative standard deviation% values were lower than 2.8 % for all analytes. As a proof-of-concept the proposed system was used for environmental water analysis, providing relative recoveries within the range of 94.0 and 104.4 %. The Green Analytical Procedure Index and Blue Applicability Grade Index proved reduced environmental impact and high practicality for the proposed method.

Highly efficient natural deep eutectic solvent-based liquid-liquid microextraction and inductively coupled plasma mass spectrometry for selective determination of inorganic selenium species in nut samples

A novel method involving the use of a hydrophobic natural deep eutectic solvent (NADES) in the vortex-assisted liquid-liquid microextraction technique based on the solidification of floating NADES for inorganic Se speciation analysis was developed. In this work, Se(IV) species was selectively complexed with ammonium pyrrolidinedithiocarbamate (APDC) and extracted with 50 μL of the NADES thymol:decanoic acid (THY:DA) (1:2) followed by fast phase separation upon freezing. Se(VI) species remaining in the aqueous phase was directly determined by inductively coupled plasma mass spectrometry (ICP-MS) while total inorganic Se concentration was determined by direct analysis of the acidic extract originated from the samples. Therefore, Se(IV) was calculated by subtracting the concentration of Se(VI) from the total inorganic Se concentration. Extraction conditions such as pH, sample volume, and type and volume of NADES were optimized, yielding an extraction efficiency of 99.6% for Se(IV). Limits of detection of 0.31 μg L−1 for Se(IV) and 0.24 μg L−1 for Se(VI), relative standard deviations of 3.5% for Se(IV) and 3.0% for Se(VI) and a linear range of 0.78–1000 μg L−1 were obtained. This work reports the first application of the NADES THY:DA (1:2) for the separation and determination of Se species in complex matrix samples such as almond, hazel nut, peanut, walnut, cashew nut, pecan nut and Brazil nut.

New insights into the downregulation of cytochrome P450 2E1 via nuclear factor κB-dependent pathways in immune-mediated liver injury

The extent of immune-mediated hepatic damage (such as in viral hepatitis) is characterised by the downregulation of cytochrome P450s (CYPs), a class of drug-metabolising enzymes. However, whether this downregulation aids liver cells in maintaining their homeostasis or whether the damage is aggravated remains largely unexplored. Herein, we evaluated the effects of phosphorylation mediated by the protein kinase C (PKC)/cAMP-response element binding protein (CREB) and nitration mediated by inducible nitric oxide synthase (iNOS) on the downregulation of CYP2E1 during immune-mediated liver injury. Additionally, we investigated the regulatory mechanism mediated by the nuclear factor κB (NF-κB). The rat model of immune-mediated liver injury was replicated by administering a single i.v. injection of Bacillus Calmette–Guerin (BCG, 125 mg/kg) vaccine and three i.p. injections of ammonium pyrrolidine dithiocarbamate (25, 50, 100 mg/kg/d, days 11, 12, and 13); blood was then collected on day 14. Subsequently, the livers were extracted to identify the different pharmacokinetic and biochemical indicators involved in the process. Our study reports new findings on the dependence between PKC-mediated CREB phosphorylation in the anti-inflammatory pathway and nitration emergency induced by iNOS in pro-inflammatory pathways in the NF-κB pathway. The interaction of these two pathways leads to the downregulation and recovery of CYP2E1, thus alleviating inflammation and nitration stress. Our results confirm that BCG-mediated downregulation of CYP2E1 is linked to iNOS-induced nitration and PKC/NF-κB-mediated CREB phosphorylation, and that NF-κB is an important molecular target in this process. These findings suggest that the downregulation of CYP2E1 may be an autonomous process characteristic of liver cells, helping them adapt to environmental changes, alleviate further hypoxia in inflamed tissues, and minimise exposure to toxic and harmful metabolites.

A-341 Development and Validation of an ICP-MS Method to Quantify Lead in Dried Blood Spots

Abstract Introduction The CDC estimates that ∼500 000 children in the US between ages 1–5 have unsafe blood lead concentrations (> 3.5 ug/dL). Lead toxicity can affect all bodily systems and can be detrimental to children's developing brains and nervous systems. Since lead exposure does not always induce obvious and immediate symptoms, screening is an essential tool to public health. Recently, there was a point of care device recalled that was used to measure blood lead across the country. The demise of this method left a gap for lead screening nationally. Dried blood spot (DBS) sampling is an excellent alternative to traditional collections as it is cost effective, less contamination prone, less invasive, and is amenable to non-standard collection locations. The objective of this study was to develop an accurate and precise DBS lead method with the intention of improving access to screening in underserved populations. Methods Lead was detected using an Agilent7800 ICP-MS. DBS were punched (6mm) and lead was extracted into a water based diluent containing EDTA, ammonium pyrrolidine dithiocarbamate, tetramethylammonium hydroxide, Triton X-100, ethanol and iridium. All DBS were sampled from Whatman903 protein saver cards using a 6mm punch. A 6-point calibration curve was made using custom UTAK whole blood lead controls and a diluent blank (target concentrations: 0, 1, 7, 14, 60 and 100 ug/dL). Exact concentrations of the liquid calibrators were determined using a previously validated lead whole blood method. Once the whole blood calibration concentrations were determined, 40 uL of each calibrator was spotted and allowed to dry for at least 24 hours before a 6mm spot was punched and extracted. Precision was determined using three concentrations of UTAK Whole Blood Lead QC (40 uL/spot; 6mm punch). Each level was run in replicates of five for five days. Linearity was confirmed by running five levels of DBS calibration standards for five days. Accuracy was evaluated using Wisconsin DBS Event Proficiency Testing (PT) Samples and results were compared to the peer means. For the method comparison, venous whole blood samples were collected into Royal Blue EDTA metal free vacutainer tubes; DBS samples were spotted directly from the finger (n = 20). Additional comparison samples (n = 10) were derived from the Pennsylvania whole blood PT program by spotting 40 uL. Results The interday precision for the low, mid, and high QC material was 5.0%, 7.5%, and 3.0% at concentrations of 6.8, 20.7, and 35.8 ug/dL, respectively. Lead concentrations from 1.0–100 ug/dL were within the allowable nonlinearity of 1 ug/dL or 5.0% (y = 1.01x-1.6;R = 0.999). Wisconsin DBS PT results (n = 12; range 0.0–38 ug/dL) were accurate within 10% of the peer mean and within acceptability criteria. Comparison of paired whole blood to DBS samples had an average bias of 4.68% (0.31 ug/dL; Y = 1.027x + 0.13(R = 0.999); range 0.1–77.7 ug/dL). Conclusions We developed and validated an accurate and precise lead DBS method using matrix-matched calibrators. This method supports that DBS collection may be an adequate sample to screen for lead exposure and could supplement the current need for additional ways to screen underserved and/or remote populations.

Speciation analysis of inorganic arsenic in water samples using thiol-ligand and cotton fibres followed by ICP-OES determination

ABSTRACT This research aimed to develop a method for the speciation analysis of arsenic species, including As(III) and As(V) in environmental samples. Cotton fibres and thiol-ligands, including ammonium pyrrolidine dithiocarbamate (APDC), L-cysteine, and diethyldithiocarbamic acid (DDTC), were used as a simple solid phase extraction (SPE) followed by arsenic determination using inductively coupled plasma optical emission spectrometry (ICP-OES). The separation parameters were thoroughly investigated, including pH, thiol-ligand concentration, cotton fibre amount, type of eluents, and flow rate. It was found that As(III) could be efficiently separated from As(V) by using a column containing 0.5 g cotton fibres and 0.1% APDC under pH 2. As(III) was then eluted using 5 mL of mixed solvents of 4 M HNO3, 4 M HCl, and 0.5 M H2O2 (1:1:1 v/v). The method was then used to perform a speciation analysis of arsenic in model solutions with As(III) and As(V) concentrations ranging from 10–1000 μg/L. The results showed good recoveries of both arsenic species at 80–120% with a satisfactory percentage relative standard deviation (%RSD). The developed method was subsequently applied for arsenic speciation analysis in the environmental samples, including natural and wastewater samples.

Matrix removal and enrichment of cadmium atnd lead in mineral‐rich samples using liquid‐liquid extraction and analysis by flame atomic absorption spectrometry

AbstractThe present work aimed to study matrix removal and enrichment of cadmium and lead in samples containing highly mineral‐rich using liquid‐liquid extraction. Cadmium and lead were extracted by sodium diethyldithiocarbamate (DDTC) and ammonium pyrrolidine dithiocarbamate (APDC) in pH 5.0 buffer solution (acetic acid/acetate) to chloroform. Cd and Pb in chloroform were re‐extracted to the aqueous phase by 1.5 M HNO3 and subsequently determined by flame atomic absorption spectrometry (F–AAS). Mineral‐rich samples (soil, sediment, sea salt, etc.) containing various concentrations of interferent elements (Fe (8‐25%), Al (5‐20%), Cu (400‐500 ppm), Zn (300‐400 ppm), NaCl (up to ⁓100%)) were used to determine the effectiveness of matrix removal. Fe was found to form an undissolved complex with APDC and co‐extracted with Cd and Pb, deteriorating the extraction and following analysis manipulation. 8‐hydroxyquinoline was successfully used as a masking reagent to reduce the co‐extraction of Fe, Al, and other elements with Cd and Pb in the form of dithiocarbamate complexes. In this study, enrichment factors of 5 – 10 could be achieved (from 50 to 5 mL). The recoveries of Cd2+ and Pb2+ ions from spiked agricultural soil, tea–planted soil, basalt soil, forestry soil, livestock feed, and sea salt were 97‐101 % and 87‐92% for DDTC and APDC reagents, respectively. The detection limits of cadmium and lead in soil are 0.0069 and 0.072 μgg−1; in livestock feed, 0.0085 and 0.082 μgg−1; in sea salt, 0.0075 and 0.076 μgg−1, respectively The quantification limit of cadmium and lead in a soil sample is 0.023 and 0.24 μgg−1; in livestock feed of 0.028 and 0.27 μgg−1; and in sea salt of 0.025 and 0.25 mgKg−1, respectively. The proposed approach for matrix removal and pre‐concentration of cadmium and lead can also be applied for mineral‐rich samples with better analytical performances when higher sensitivity and multi‐element detection techniques such as inductively coupled plasma optical emission spectrometry or inductively coupled plasma mass spectrometry are used.

Design, Synthesis, and Evaluation of the COX-2 Inhibitory Activities of New 1,3-Dihydro-2H-indolin-2-one Derivatives.

Thirty-three 1,3-dihydro-2H-indolin-2-one derivatives bearing α, β-unsaturated ketones were designed and synthesized via the Knoevenagel condensation reaction. The cytotoxicity, in vitro anti-inflammatory ability, and in vitro COX-2 inhibitory activity of all the compounds were evaluated. Compounds 4a, 4e, 4i-4j, and 9d exhibited weak cytotoxicity and different degrees of inhibition against NO production in LPS-stimulated RAW 264.7 cells. The IC50 values of compounds 4a, 4i, and 4j were 17.81 ± 1.86 μM, 20.41 ± 1.61 μM, and 16.31 ± 0.35 μM, respectively. Compounds 4e and 9d showed better anti-inflammatory activity with IC50 values of 13.51 ± 0.48 μM and 10.03 ± 0.27 μM, respectively, which were lower than those of the positive control ammonium pyrrolidinedithiocarbamate (PDTC). Compounds 4e, 9h, and 9i showed good COX-2 inhibitory activities with IC50 values of 2.35 ± 0.04 µM, 2.422 ± 0.10 µM and 3.34 ± 0.05 µM, respectively. Moreover, the possible mechanism by which COX-2 recognized 4e, 9h, and 9i was predicted by molecular docking. The results of this research suggested that compounds 4e, 9h, and 9i might be new anti-inflammatory lead compounds for further optimization and evaluation.

Microwave-Assisted Digestion of Polyurethane Foam as an Alternative to Elution: Solid Phase Extraction of Cd(II) and Pb(II) for Their Determination in Swimming Pool Waters.

In this work, a separation/preconcentration method is proposed for the determination of Cd(II) and Pb(II) in swimming pool waters, using ammonium pyrrolidine dithiocarbamate (APDC) as a complexing agent and unloaded polyurethane foam (PUF) as a sorbent. The proposed method was optimized, and the defined optimal conditions were a pH of 7, 30 min of shaking time, 400 mg of PUF, and 0.5% (m/v) of the APDC solution. The release of Cd(II) and Pb(II) from the solid phase was achieved through the total digestion of PUF using a microwave-assisted acid approach with a 10.5 mol·L-1 HNO3 solution. The methodology was applied to four samples of swimming pool water for the determination of Cd(II) and Pb(II) using graphite furnace atomic absorption spectrometry (GF AAS). The limits of detection and quantification obtained were 0.02 and 0.06 μg·L-1 for Cd(II) and 0.5 e 1.8 μg·L-1 for Pb(II), respectively. We analyzed four samples of swimming pool waters, finding Cd concentrations between 0.22 and 1.37 μg·L-1. On the other hand, only one sample presented Pb concentration above the limit of quantification (11.4 μg·L-1). Recovery tests were performed by spiking the samples with known concentrations of the analytes, and recovery percentages between 82% and 105% were obtained.

Platycodin D inhibits HFD/STZ-induced diabetic nephropathy via inflammatory and apoptotic signaling pathways in C57BL/6 mice

Ethnopharmacological relevanceThe dried root of Platycodon grandiflorum (Jacq.) A.DC. (PG) is a traditional herb used in Asian countries and is widely used in formulas for the treatment of diabetes. Platycodin D (PD) is one of the most important components of PG. Aim of the studyThis study aimed to investigate the improvement effects and regulatory mechanisms of PD on kidney injury in a high-fat diet (HFD) combined with streptozotocin (STZ)-induced diabetic nephropathy (DN). Materials and methodsModel mice were treated with oral gavage of the PD (2.5, 5 mg/kg) for 8 weeks. Determination of serum lipid and renal function-related indexes creatinine (CRE), and blood urea nitrogen (BUN) levels in mice, and histopathological section analysis of kidney. Molecular docking and molecular dynamics were utilized to study the binding ability of PD to target NF-κB and apoptosis signaling pathway-related proteins. Moreover, Western blot was used to test the expressions of NF-κB and apoptosis-related proteins. Vitro experiments were performed to validate the related mechanisms using RAW264.7 cells and HK2 cells cultured by high glucose. ResultsIn vivo experiments, the administration of PD (2.5 and 5.0 mg/kg) reduced fasting blood glucose (FBG) and homeostasis model assessment of insulin resistance (HOMA-IR) levels in DN mice, while lipid levels and renal function were significantly improved. Furthermore, PD significantly inhibited the development of DN in the model mice by regulating NF-κB and apoptotic signaling pathways, reduced the abnormal elevation of serum inflammatory factors TNF-α and IL-1β, and repaired renal cell apoptosis. In vitro experiments, NF-κB inhibitor ammonium pyrrolidine dithiocarbamate (PDTC) was used to confirm that PD can alleviate high glucose-induced inflammation in RAW264.7 cells and inhibit the release of inflammatory factors. And in HK2 cell experiments, it was verified that PD can inhibit ROS generation, reduce the loss of JC-1 and suppress HK2 cell injury by regulating NF-κB and apoptotic pathways. ConclusionsThese data suggested that PD has the potential to prevent and treat DN and is a promising natural nephroprotective agent.

Edible oil-based switchable-hydrophilicity solvent liquid–liquid microextraction for the determination of lead in food samples using flame-atomic absorption spectrometry

Edible oil-based switchable-hydrophilicity solvent liquid–liquid microextraction (EO-SHS-LLME) was used prior to the determination of lead as its metal chelate with ammonium pyrrolidine dithiocarbamate (APDC) by flame-atomic absorption spectrometry. Optimum extraction conditions were achieved using 600 µL of coconut oil as the extraction solvent, pH of sample solution adjusted to 4.50 and containing 1.0% (w/v) APDC, within 5.0 min complexation time, a 300 µL of 2.0 M sulfuric acid as the hydrophilicity switching-off trigger, and 150 µL of 8.0 M nitric acid as the back-extraction solution within 4.0 min back-extraction time. The limits of detection and quantification were found as 2.8 and 9.4 µg g−1, respectively. Good linearity was obtained with coefficients of determination (R2) higher than 0.9961. Intraday and interday precision, expressed in terms of relative standard deviation, were less than 4.0% and 4.6%, respectively, while the linear dynamic range was from 12.6 to 175.0 µg g−1. Accuracy was checked by addition-recovery tests and percentage recoveries were found to be within the range of 97.1–106.0%. The proposed method was applied for the determination of lead in food samples (i.e., carrot, fish, onion, potato and yam) and satisfactory results were achieved.