Studies on acute and chronic toxicity of cadmium to freshwater snail Lymnaea acuminata (Lamarck) with special reference to behavioral and hematological changes

Abstract

Molluscs have long been regarded as promising bioindicator and biomonitoring subjects for heavy metals as molluscs are highly tolerant to heavy metals and exhibit high accumulation in their body. In spite of several previous studies about the impact of cadmium on molluscs, little information exists in literatures concerning the toxic effects of cadmium on Lymnaea acuminata, especially pertaining to behavioral and hematological changes as these are considered effective bioindicators and biomonitoring variables for detecting heavy metals in polluted water bodies. In the present study, the median lethal concentrations of cadmium chloride to snail, Lymnaea acuminata, were estimated to be 9.66, 7.69, 6.26, and 5.54 mg/L at 24, 48, 72, and 96 h, respectively. For behavioral studies, variable test concentrations of cadmium from 0.00 to 10 mg/L were used. The clumping tendency, crawling activity, and touch reflex in the exposed snails were gradually decreased with higher concentrations at 72 and 96 h. For measuring the hemocyte numbers in the circulating hemolymph of snail during chronic cadmium exposure, two sublethal doses of cadmium (10 and 20% 96-h LC₅₀—0.55 and 1.11 mg/L, respectively) were used. A significant variation (p < 0.05) from the control at all exposure times (7, 14, 21, and 28 days) was recorded at 1.11 mg/L concentration. The total count of circulating hemocytes was significantly reduced (p < 0.05) compared to the controls at both concentrations of cadmium exposure at all time periods except 14 and 21 days exposure at 0.55 mg/L where values were non-significantly increased. In comparison between two sublethal doses, blood cells were significantly (p < 0.05) lowered at 1.11 mg/L cadmium treatment. Considering the behavioral and hematological data, it seems possible to forecast the physiological state of snails in cadmium-contaminated water bodies and these findings can be used in determining the safe disposal level of cadmium in aquatic ecosystem.

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Fractions and transformation of organic phosphorus in sediments from a eutrophic lake in China

Abstract

Several organic phosphorus compounds (Po) in sediment from a representative eutrophic lake were surveyed using a sequential fractionation procedure, which included microbial biomass phosphorus (Biomass-P), fulvic acid phosphorus (FA-P), humic acid phosphorus (HU-P), and residual phosphorus (Res-P). In addition, several organic compounds including orthophosphate monoesters, orthophosphate diesters, and pyrophosphate were simultaneously measured using ³¹P nuclear magnetic resonance (³¹P NMR). Results showed that Po contributed over 50% of total phosphorus (TP), and the average concentration of Po species generally decreased from Res-P > FA-P > HU-P > Biomass-P. Additionally, the relative proportions of phosphorus compounds in the sediment followed the decreasing order of orthophosphate monoesters > orthophosphate diesters > pyrophosphate. In general, Po was the dominant phosphorus species. Residual P was not a single species but comprised of a group of species, and tended to be stable. Although orthophosphate monoesters had the highest concentrations and ratios in Po, orthophosphate diesters displayed a more distinct remineralization trend. Principal component analysis (PCA) coupled with correlation analysis suggested that a greater amount of orthophosphate diesters resided in Res-P, than HU-P or FA-P.

http://ift.tt/2x8PpvZ

Organic ligand induced release of vanadium from the dissolution of stone coal oxide ore

Abstract

The effects of low-molecular-weight dissolved organic matters (LMWDOMs) on the release of vanadium (V) under environmental conditions are part of a broader study on the environmental geochemistry behavior of V. Eight typical naturally occurring LMWDOMs with carboxyl, hydroxyl, and amidogen groups were chosen: citric acid, oxalic acid, EDTA, salicylic acid, catechol, glycine, cysteine, and glucose. The results showed that the release of V was largely promoted by LMWDOMs with carboxyl functional groups under acidic conditions and with catechol under basic conditions. In the presence of citric acid, oxalic acid, or EDTA at pH 4.0, the initial release rates of V were approximately 25–39 times greater than the rates in the control experiments; the steady release rates were 164, 95, and 49 times than the rates in the control experiments, respectively. For catechol, the release rate at pH 8.0 was approximately 20 times the rate at pH 4.0. Amino acids and alcohols had a minimal effect on the release of V. Ligand-promoted release rates of V were found primarily due to the faster detachment of surface complexes, the protonated sites from the mineral surface and the reduction of dissolved V (V) in the presence of citric acid, oxalic acid, EDTA, and catechol. This study helps understand the pollution risk of V in some mine areas and the fate of V in the environment.

http://ift.tt/2g2Sx1R

Controlled modification of electrochemical microsystems with polyethylenimine/reduced graphene oxide using electrophoretic deposition: Sensing of dopamine levels in meat samples

Publication date: 1 February 2018
Source:Talanta, Volume 178
Author(s): Karima Kahlouche, Roxana Jijie, Ioana Hosu, Alexandre Barras, Tijani Gharbi, Reda Yahiaoui, Guillaume Herlem, Marhoun Ferhat, Sabine Szunerits, Rabah Boukherroub
Microsystems play an important role in many biological and environmental applications. The integration of electrical interfaces into such miniaturized systems provides new opportunities for electrochemical sensing where high sensitivity and selectivity towards the analyte are requested. This can be only achieved upon controlled functionalization of the working electrode, a challenge for compact microsystems. In this work, we demonstrate the benefit of electrophoretic deposition (EPD) of reduced graphene oxide/polyethylenimine (rGO/PEI) for the selective modification of a gold (Au) microelectrode in a microsystem comprising a Pt counter and a Ag/AgCl reference electrode. The functionalized microsystem was successfully applied for the sensing of dopamine with a detection limit of 50nM. Additionally, the microsystem exhibited good performance for the detection of dopamine levels in meat samples.

Graphical abstract

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Determination of bisphenols with estrogenic activity in plastic packaged baby food samples using solid-liquid extraction and clean-up with dispersive sorbents followed by gas chromatography tandem mass spectrometry analysis

Publication date: 1 February 2018
Source:Talanta, Volume 178
Author(s): M.T. García-Córcoles, M. Cipa, R. Rodríguez-Gómez, A. Rivas, F. Olea-Serrano, J.L. Vílchez, A. Zafra-Gómez
Bisphenols (BPs) are a family of chemicals with known endocrine disrupting activity. Bisphenol A (BPA) is the most representative prototype of this group of chemicals. Recently, the use of BPA, a prototype of endocrine disruptors, has been reduced and replaced with structural analogs due to its negative effects on both the environment and consumers. In this work, a new method is presented for the determination of seven BPs, with estrogenic activity in ready-to-eat plastic packaged baby foods. The procedure involves the isolation of the analytes using solid-liquid phase extraction with acetonitrile followed by a clean-up step with a mixture of dispersive-SPE sorbents (C18 and PSA) and magnesium sulphate, to reduce matrix effect from proteins, sugars and lipids. Extraction parameters were optimized using multivariate optimization methods. The compounds were detected and quantified by gas chromatography tandem mass spectrometry (GC–MS/MS). The limits of quantification were between 0.1 and 1.2ngg⁻¹ for the studied analytes. The method was validated using matrix–matched calibration and recovery assays with spiked samples. Recovery rates were between 91% and 110% and % RSD was lower than 13% in all cases. The method has been successfully applied for the determination of these endocrine disrupting chemicals (EDCs) in samples of a novel type of food consumed by pre-schoolers. This is the first study to analyze EDCs in plastic packaged foods consumed by this target group.

Graphical abstract

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How to write a Critically Appraised Topic: evidence to underpin routine clinical practice

Summary

Critically appraised topics (CATs) are essential tools for busy clinicians who wish to ensure that their daily clinical practice is underpinned by evidence-based medicine. CATs are short summaries of the most up-to-date, high-quality available evidence that is found using thorough structured methods. They can be used to answer specific, patient-orientated questions that arise recurrently in real-life practice. This article provides readers with a detailed guide to performing their own CATs. It is split into four main sections reflecting the four main steps involved in performing a CAT: formulation of a focused question, a search for the most relevant and highest-quality evidence, critical appraisal of the evidence and application of the results back to the patient scenario. As well as helping to improve patient care on an individual basis by answering specific clinical questions that arise, CATs can help spread and share knowledge with colleagues on an international level through publication in the evidence-based dermatology section of the British Journal of Dermatology.

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Inhibition of hepatocyte nuclear factor 1b induces hepatic steatosis through DPP4/NOX1-mediated regulation of superoxide

Publication date: December 2017
Source:Free Radical Biology and Medicine, Volume 113
Author(s): Zi Long, Meng Cao, Shuhao Su, Guangyuan Wu, Fansen Meng, Hao Wu, Jiangzheng Liu, Weihua Yu, Kamran Atabai, Xin Wang
Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder that is closely associated with insulin resistance and type 2 diabetes. Previous studies have suggested that hepatocyte nuclear factor 1b (HNF1b) ameliorates insulin resistance. However, the role of HNF1b in the regulation of lipid metabolism and hepatic steatosis remains poorly understood. We found that HNF1b expression was decreased in steatotic livers. We injected mice with lentivirus (LV) expressing HNF1b shRNA to generate mice with hepatic knockdown of HNF1b. We also injected high fat (HF) diet-induced obese and db/db diabetic mice with LV expressing HNF1b to overexpress HNF1b. Knockdown of HNF1b increased hepatic lipid contents and induced insulin resistance in mice and in hepatocytes. Knockdown of HNF1b worsened HF diet-induced increases in hepatic lipid contents, liver injury and insulin resistance in mice and PA-induced lipid accumulation and impaired insulin signaling in hepatocytes. Moreover, overexpression of HNF1b alleviated HF diet-induced increases in hepatic lipid content and insulin resistance in mice. Knockdown of HNF1b increased expression of genes associated with lipogenensis and endoplasmic reticulum (ER) stress. DPP4 and NOX1 expression was increased by knockdown of HNF1b and HNF1b directly bound with the promoters of DPP4 and NOX1. Overexpression of DPP4 or NOX1 was associated with an increase in lipid droplets in hepatocytes and decreased expression of DPP4 or NOX1 suppressed the effects of knockdown of HNF1b knockdown on triglyceride (TG) formation and insulin signaling. Knockdown of HNF1b increased superoxide level and decreased glutathione content, which was inhibited by downregulation of DPP4 and NOX1. N-acetylcysteine (NAC) suppressed HNF1b knockdown-induced ER stress, TG formation and insulin resistance. Palmitic acid (PA) decreased HNF1b expression which was inhibited by NAC. Taken together, these studies demonstrate that HNF1b plays an essential role in controlling hepatic TG homeostasis and insulin sensitivity by regulating DPP4/NOX1mediated generation of superoxide.

Graphical abstract

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Comparative effects of schisandrin A, B, and C on Propionibacterium acnes-induced, NLRP3 inflammasome activation-mediated IL-1β secretion and pyroptosis

Publication date: December 2017
Source:Biomedicine & Pharmacotherapy, Volume 96
Author(s): Miaomiao Guo, Faliang An, Haiyuan Yu, Xing Wei, Minhua Hong, Yanhua Lu
Propionibacterium acnes, a common pathogen associated with acne, is also responsible for various surgical infections. Schisandrin A, schisandrin B and schisandrin C, the representative lignans of Schisandra chinensis (Turcz.) Baill. extract, inhibit P. acnes-induced inflammation. However, their effects on P. acnes-induced IL-1β secretion and pyroptosis mediated by NLRP3 inflammasome activation remain unknown. In this study, we compared the effects of schisandrin A, B, and C (Sch A, B, and C) on IL-1β secretion and pyroptosis in P. acnes-infected THP-1 cells. As NLRP3 plays important roles in P. acnes-mediated inflammation and pyroptosis, we also investigated the effects of Schs on P. acnes-induced NLRP3 inflammasome activation by measuring the levels of NLRP3, active caspase-1, and mature IL-1β, and activity of caspase-1. Our results showed that Sch A, B, and C suppressed P. acnes-induced pyroptosis. Further, the three lignans significantly suppressed NLRP3 inflammasome activation, with the following potency: Sch C > Sch B > Sch A. Three lignans also inhibited the production of mitochondrial ROS and ATP release. Additionally, Sch B and C almost completely prevented the efflux of K^+., whereas Sch A had a relatively weak effect. Collectively, our novel findings showed that Sch A, B, and C effectively suppressed IL-1β secretion and pyroptosis by inhibiting NLRP3 inflammasome activation in P. acnes-infected THP-1 cells. Thus, Schs may be promising agents for the treatment of P. acnes-related infections.



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Paeoniflorin ameliorates Adriamycin-induced nephrotic syndrome through the PPARγ/ANGPTL4 pathway in vivo and vitro

Publication date: December 2017
Source:Biomedicine & Pharmacotherapy, Volume 96
Author(s): Ruirui Lu, Jie Zhou, Bihao Liu, Ning Liang, Yu He, Lixia Bai, Peichun Zhang, Yanchun Zhong, Yuan Zhou, Jiuyao Zhou
Paeoniflorin (PF), an effective composition that is extracted from Radix Paeoniae Alba, plays a role in protecting against various kidney diseases. However, the mechanism of PF on nephrotic syndrome (NS) remains unclear. The aim of this study was to investigate the protective role of PF on Adriamycin (ADR)-induced NS in vivo and vitro as well as its potential mechanism. In animal study, PF significantly decreased the levels of 24-h urine protein, blood urea nitrogen, serum creatinine, total cholesterol and triglycerides in NS rats, but increased the total protein and albumin levels. Hematoxylin-eosin (HE) staining revealed that the kidney lesion was resolved upon PF treatment. After treatment with PF, the morphology and number of podocytes in renal tissue were restored to normal. PF increased expression of synaptopodin and decreased expression of desmin, demonstrating a protective effect in podocyte injury. Further studies revealed that PF upregulated Peroxisome proliferator-activated receptor gamma (PPARγ) and restrained Angiopointin-like 4 (ANGPTL4) in kidney tissue. In vitro study, PF reduced Caspase3 and Bax and increased Bcl-2, indicating that the apoptosis rate of podocytes induced by ADR was reduced by PF. Furthermore, PF ameliorated podocyte injury by upregulating synaptopodin and reducing desmin. In accordance with animal study, PF downregulated ANGPTL4 by activating PPARγ. However, the therapeutic effects of PF were reversed by GW9662 (PPARγ inhibitor), likely by suppressing ANGPTL4 degradation. In general, these results demonstrate that PF has a good therapeutic effect on NS by activating PPARγ and subsequently inhibiting ANGPTL4.

Graphical abstract

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Lianqinjiedu decoction attenuates LPS-induced inflammation and acute lung injury in rats via TLR4/NF-κB pathway

Publication date: December 2017
Source:Biomedicine & Pharmacotherapy, Volume 96
Author(s): Guiming Deng, Hai He, Zheng Chen, Linqi OuYang, Xiaoqin Xiao, Jinwen Ge, Biao Xiang, Sichen Jiang, Shaowu Cheng
Acute lung injury (ALI) and its severe form acute respiratory distress syndrome remain the leading cause of morbidity and mortality. LianQinJieDu (LQJD), which is a traditional Chinese medicine, has been clinically used for antiviral drug. The present study investigated whether Lianqinjiedu(LQJD) ameliorates lipopolysaccharide(LPS)-induced acute lung injury in rats and aimed to determine the anti-inflammatory effects of LQJD. Rat model with ALI induced by intraperitoneal injection of LPS was treated by oral administration of LQJD. The recruitment of body temperature and the histopathology of lung tissue from all groups were evaluated to grade the severity of the inflammation. The inflammatory cytokine levels, including tumor necrosis factor-α (TNF-α)and interleukin-6 (IL-6), were examined by ELISA assay, and the TLR4 and NF-κBp65 expression levels were evaluated by Real time-PCR and western blotting. It was observed that LQJD reduced the LPS-induced body temperature, inflammatory cytokines level, and lung injuries, and blocked the activation of TLR4/NF-κBp65 signaling in lung tissue. This study demonstrates that LQJD has a protective effect on LPS-induced inflammatory rats through the signaling pathway of TLR4 and NF-κBp65.



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Binding of triazole-linked galactosyl arylsulfonamides to galectin-3 affects Trypanosoma cruzi cell invasion

Publication date: Available online 30 September 2017
Source:Bioorganic & Medicinal Chemistry
Author(s): Marcelo Fiori Marchiori, Thalita B. Riul, Leandro Oliveira Bortot, Peterson Andrade, Getúlio G. Junqueira, Giuseppina Foca, Nunzianna Doti, Menotti Ruvo, Marcelo Dias-Baruffi, Ivone Carvalho, Vanessa Leiria Campo
The synthesis of the O-3 triazole-linked galactosyl arylsulfonamides 1-7 as potential inhibitors of Trypanosoma cruzi cell invasion is described. These target compounds were synthesized by Cu(I)-catalysed azide-alkyne cycloaddition reaction ('click chemistry') between different azide arylsulfonamides and the alkyne-based sugar 3-O-propynyl-βGalOMe. Inhibition assays of T. cruzi cell invasion with compounds 1-7 showed reduced values of infection index (∼20) for compounds 3 and 5, bearing the corresponding 5-methylisoxazole and 2,4-dimethoxypyrimidine groups, which also presented higher binding affinities to galectin-3 (EC50 17-18 μM) in Corning Epic label-free assays. In agreement with experimental results, the assessment of the theoretical binding of compounds 1-7 to galectin-3 by MM/PBSA method displayed higher affinities for compounds 3 (-9.7 Kcal/ mol) and 5 (-11.1 Kcal/ mol). Overall, these achievements highlight compounds 3 and 5 as potential T. cruzi cell invasion blockers by means of a galectin-3 binding-related mechanism, revealing galectin-3 as an important host target for design of novel anti-trypanosomal agents.

Graphical abstract

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Phosphamide-Containing Diphenylpyrimidine Analogues (PA-DPPYs) as Potent Focal Adhesion Kinase (FAK) Inhibitors with Enhanced Activity against Pancreatic Cancer Cell Lines

Publication date: Available online 30 September 2017
Source:Bioorganic & Medicinal Chemistry
Author(s): He Liu, Bin Wu, Yang Ge, Jiaxin Xu, Shijie Song, Changyuan Wang, Jihong Yao, Kexin Liu, Yanxia Li, Xiuli Sun, Xiaodong Ma
A family of phosphamide-containing diphenylpyrimidine analogues (PA-DPPYs) were synthesized as potent focal adhesion kinase (FAK) inhibitors. The PA-DPPY derivatives could significantly inhibit the FAK enzymatic activity within concentrations of lower than 10.69 nM. Among them, compounds 7a and 7e were two of the most active FAK inhibitors, possessing IC50 values of 4.25 nM and 4.65 nM, respectively. In particular, compound 7e also displayed strong activity against AsPC cell line, with an IC50 of 1.66 μM, but show low activity against the normal HPDE6-C7 cells (IC50 > 20 μM), indicating its low cell cytoxicity. Additionally, flow cytometry analysis showed that after treatment of 7e (8 μM, 72 h), both AsPC and Panc cells were almost totally inhibited, with a cell viability rate of 16.8% and 18.1%, respectively. Overall, compound 7e may be served as a valuable FAK inhibitor for the treatment of pancreatic cancer.

Graphical abstract

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Peptides for optical medical imaging and steps towards therapy

Publication date: Available online 30 September 2017
Source:Bioorganic & Medicinal Chemistry
Author(s): Matteo Staderini, Alicia Megia-Fernandez, Kevin Dhaliwal, Mark Bradley
Optical medical imaging is a rapidly growing area of research and development that offers a multitude of healthcare solutions both diagnostically and therapeutically. In this review some of the most recently described peptide-based optical probes are reviewed with a special emphasis on their in vivo use and potential application in a clinical setting.

Graphical abstract

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Teixobactin as a scaffold for unlimited new antimicrobial peptides: SAR study

Publication date: Available online 30 September 2017
Source:Bioorganic & Medicinal Chemistry
Author(s): Shimaa A. H. Abdel Monaim, Yahya E. Jad, Ayman El-Faham, Beatriz G. de la Torre, Fernando Albericio
It looks that a new era of antimicrobial peptides (AMPs) started with the discovery of teixobactin, which is a "head to side-chain" cyclodepsipeptide. It was isolated from a soil gram-negative b-proteobacteria by means of a revolutionary technique. Since there, several groups have developed synthetic strategies for efficient synthesis of this peptide and its analogues as well. Herein, all chemistries reported as well as the biological activity of the analogues are analyzed. Finally, some inputs regarding new trends for the next generation of analogues are discussed.

Graphical abstract

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