Three asymmetric tridentate acyl hydrazone Schiff base ligands namely L1, L2 and L3 were prepared via condensation of 4-methoxybenzohydrazide with picolinaldehyde, 1-(pyridin-2-yl)ethanone and ...phenyl(pyridin-2-yl)methanone respectively. Three bio-relevant mononuclear zinc(ii) complexes Zn(L1)Cl
·2H
O (1), Zn(L2)Cl
(2) and Zn(L3)Cl
(3) were synthesized by treatment of zinc(ii) chloride with the corresponding Schiff base ligands and characterised by the usual physicochemical techniques. The solid state structures of complexes 1 and 3 were evaluated by single crystal X-ray analysis. All complexes were able to hydrolyse the P-O bond of the phosphate monoester in 90% (v/v) DMSO-water medium using 4-nitrophenylphosphate (4-NPP) as the model substrate and the trend in their activity is 1≈2 > 3. On considering the highly efficient hydrolysis properties, complexes 1-3 were tested as potential therapeutic agents for cancer using HCT116 (human colorectal carcinoma), HepG2 (human hepatocellular carcinoma) and A549 (human non-small lung carcinoma) cells. Complex 2 showed the highest IC
values for anti-cancer activity towards all three cell lines among the three complexes and complex 3 showed the least activity as observed in the phosphatase activity study. The internucleosomal degradation of DNA during apoptosis can be detected by cell death detection ELISA. DNA fragmentation that leads to cell death was examined and when induced by complex 2 in HepG2 cells a significant level of DNA fragmentation was observed at regular intervals of time.
On average, an approved drug currently costs US$2-3 billion and takes more than 10 years to develop
. In part, this is due to expensive and time-consuming wet-laboratory experiments, poor initial hit ...compounds and the high attrition rates in the (pre-)clinical phases. Structure-based virtual screening has the potential to mitigate these problems. With structure-based virtual screening, the quality of the hits improves with the number of compounds screened
. However, despite the fact that large databases of compounds exist, the ability to carry out large-scale structure-based virtual screening on computer clusters in an accessible, efficient and flexible manner has remained difficult. Here we describe VirtualFlow, a highly automated and versatile open-source platform with perfect scaling behaviour that is able to prepare and efficiently screen ultra-large libraries of compounds. VirtualFlow is able to use a variety of the most powerful docking programs. Using VirtualFlow, we prepared one of the largest and freely available ready-to-dock ligand libraries, with more than 1.4 billion commercially available molecules. To demonstrate the power of VirtualFlow, we screened more than 1 billion compounds and identified a set of structurally diverse molecules that bind to KEAP1 with submicromolar affinity. One of the lead inhibitors (iKeap1) engages KEAP1 with nanomolar affinity (dissociation constant (K
) = 114 nM) and disrupts the interaction between KEAP1 and the transcription factor NRF2. This illustrates the potential of VirtualFlow to access vast regions of the chemical space and identify molecules that bind with high affinity to target proteins.
Abstract
Ferroptosis is a non-conventional cellular death caused by lipid peroxide induced iron deposition. Intracellular lipid accumulation followed by generation of lipid peroxides is an hallmark ...of non-alcoholic fatty liver disease (NAFLD). Melatonin (MLT) is an important pineal hormone with tremendous antioxidant and anti-inflammatory properties. Various studies targeted ferroptosis in different diseases using melatonin. However, none of them focused the intrinsic mechanism of MLT’s action to counteract ferroptosis in NAFLD. Hence, the present study investigated the role of MLT in improvement of NAFLD-induced ferroptosis.
HepG2 cells were treated with free fatty acids (FFAs) to induce in vitro NAFLD state and C57BL/6 mice were fed with high-fat diet (HFD) followed by MLT administration.
The results indicated that MLT administration caused the recovery from both FFA- and HFD-induced ferroptotic state via increasing GSH and SOD level, decreasing lipid reactive oxygen species (ROS) and malondialdehyde (MDA) level, increasing Nrf2 and HO-1 level to defend cells against an oxidative environment. MLT also altered the expression of two key proteins GPX4 and SLC7A11 back to their normal levels, which would otherwise cause ferroptosis. MLT also protected against histopathological damage of both liver tissue and HepG2 cells as depicted by Oil Red O, HE staining and immunofluorescence microscopy. MLT also had control over pAMPKα as well as PPARγ and PPARα responsible for lipid homeostasis and lipogenesis.
In brief, MLT exerted its multifaceted effect in FFA- and HFD-induced NAFLD by retrieving cellular oxidative environment, reducing lipogenesis and lipid peroxidation and modulating Nrf2/HO-1 and GPX4/SLC7A11 axis to combat ferroptosis.
Elaborate control mechanisms of intracellular triacylglycerol (TAG) breakdown are critically involved in the maintenance of energy homeostasis. Hypoxia-inducible lipid droplet-associated protein ...(HILPDA)/hypoxia-inducible gene-2 (Hig-2) has been shown to affect intracellular TAG levels, yet, the underlying molecular mechanisms are unclear. Here, we show that HILPDA inhibits adipose triglyceride lipase (ATGL), the enzyme catalyzing the first step of intracellular TAG hydrolysis. HILPDA shares structural similarity with G0/G1 switch gene 2 (G0S2), an established inhibitor of ATGL. HILPDA inhibits ATGL activity in a dose-dependent manner with an IC50 value of ∼2 μM. ATGL inhibition depends on the direct physical interaction of both proteins and involves the N-terminal hydrophobic region of HILPDA and the N-terminal patatin domain-containing segment of ATGL. Finally, confocal microscopy combined with Förster resonance energy transfer-fluorescence lifetime imaging microscopy analysis indicated that HILPDA and ATGL colocalize and physically interact intracellularly. These findings provide a rational biochemical explanation for the tissue-specific increased TAG accumulation in HILPDA-overexpressing transgenic mouse models.
Microplastic particles (MP) contaminate oceans and affect marine organisms in several ways. Ingestion combined with food intake is generally reported. However, data interpretation often is ...circumvented by the difficulty to separate MP from bulk samples. Visual examination often is used as one or the only step to sort these particles. However, color, size, and shape are insufficient and often unreliable criteria. We present an extraction method based on hypochlorite digestion and isolation of MP from the membrane by sonication. The protocol is especially well adapted to a subsequent analysis by Raman spectroscopy. The method avoids fluorescence problems, allowing better identification of anthropogenic particles (AP) from stomach contents of fish by Raman spectroscopy. It was developed with commercial samples of microplastics and cotton along with stomach contents from three different Clupeiformes fishes:
Clupea harengus
,
Sardina pilchardus
, and
Engraulis encrasicolus
. The optimized digestion and isolation protocol showed no visible impact on microplastics and cotton particles while the Raman spectroscopic spectrum allowed the precise identification of microplastics and textile fibers. Thirty-five particles were isolated from nine fish stomach contents. Raman analysis has confirmed 11 microplastics and 13 fibers mainly made of cellulose or lignin. Some particles were not completely identified but contained artificial dyes. The novel approach developed in this manuscript should help to assess the presence, quantity, and composition of AP in planktivorous fish stomachs.
The present study reports the synthesis, characterization and catalytic activity of zinc/hydroxyapatite/magnesium ferrite (Zn/HAP/MgFe
2
O
4
) as a novel nanocomposite. The nanocomposite was ...characterized by powder XRD, FTIR, SEM–EDX, TEM, VSM and XPS. The presence of Zn(0) and Zn(II) in the Zn/HAP/MgFe
2
O
4
was confirmed by XPS studies. The composite was applied as a heterogeneous catalyst for the degradation of malachite green in the presence as well as in the absence of H
2
O
2
. In the presence of the oxidant H
2
O
2
, 100% degradation was achieved in just 2 min while in the absence of H
2
O
2
it took almost 2 h for complete degradation. The enhancement in the rate of the degradation of the dye in the presence of H
2
O
2
was due to fenton and fenton-like mechanism involving the formation of reactive oxygen species, such as hydroxyl and perhydroxyl radicals (HO
·
and HOO
·
). The Zn/HAP/MgFe
2
O
4
showed high stability and because of its super-paramagnetic behaviour it could be easily separated by external magnet from the reaction mixture. Kinetic studies showed that the degradation of the dye follows first order.
Green gold nanoparticles (GNPs) were prepared from black tea extract (BTE) and used to examine the chemosensitivity of doxorubicin in colon cancer cell line HCT116. BTE-GNPs were prepared by a ...single-step method and characterized by UV-Vis spectroscopy, FTIR spectroscopy, SEM, DLS and zeta-potential. The MTT assay was performed to determine the cytotoxicity of HCT116 cells and also normal kidney cells HEK293. Apoptosis and ROS generation were investigated by flow cytometry. The inhibition of ROS levels by the inhibitor NAC was determined by both spectrofluorimetry and confocal microscopy. Expression levels of pro- and anti-apoptotic proteins were determined by a western blot technique. BTE-GNPs significantly enhanced the cytotoxic effect of DOX with its co-treatment in HCT116 cells. The cytotoxic effect of BTE-GNP + DOX was involved in apoptosis
a ROS-dependent pathway by enhancing the pro-apoptotic protein expression. Therefore, our results indicated that green gold nanoparticles of black tea extract (BTE-GNP) may be potent chemosensitizers of doxorubicin.
Microplastics (MPs) are thought to be ingested by a wide range of marine organisms before being excreted. However, several studies in marine organisms from different taxa have shown that MPs and ...nanoplastics could be translocated in other organs. In this study, we investigated the presence of MPs in the livers of commercial zooplanktivorous fishes collected in the field. The study focuses mainly on the European anchovy Engraulis encrasicolus but concerns also the European pilchard Sardina pilchardus and the Atlantic herring Clupea harengus. Two complementary methodologies were used to attest the occurrence of MPs in the hepatic tissue and to exclude contamination. 1) MPs were isolated by degradation of the hepatic tissue. 2) Cryosections were made on the livers and observed in polarized light microscopy. Both methods separately revealed that MPs, mainly polyethylene (PE), were translocated into the livers of the three clupeid species. In anchovy, 80 per cent of livers contained relatively large MPs that ranged from 124 μm to 438 μm, showing a high level of contamination. Two translocation pathways are hypothesized: (i) large particles found in the liver resulted from the agglomeration of smaller pieces, and/or (ii) they simply pass through the intestinal barrier. Further studies are however required to understand the exact process.
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•Microplastics were found for the first time in liver of wild Clupeiforme fishes.•Eighty per cent of anchovies had one or more microplastic(s) in their liver.•Microplastics measured 323 μm on average.
Microplastics are translocated in the liver of wild fishes meaning that microplastic pollution has a more important impact than previously supposed.
The oxidant‐controlled divergent synthesis of C‐2′ formyl 2H‐indazoles and indazoloindazolediones has been developed through Mn(I)‐ catalyzed ortho C−H functionalization of 2H‐indazoles with ...para‐formaldehyde to afford C‐2′ hydroxymethylated 2H‐indazoles and subsequently oxidation with varying the amount of DDQ in one‐pot. By employing selectfluor as the oxidant instead of DDQ, this reaction exclusively provided indazolebenzoxazine derivatives. This strategy delivered unsymmetrical indazoloindazoledione and indazolobenzoxazine with varied functional group tolerance in moderate to good yields.
Herein, we have reported a one‐pot oxidant‐controlled synthesis of C‐2′ formyl 2H‐indazoles, along with two rare heterocycles viz. indazoloindazolediones and indazolobenzoxazines from 2‐arylindazoles through Mn(I)‐catalyzed ortho C−H functionalization followed by oxidation with varying the amount of DDQ and switching from DDQ to selectfluor, with broad range of substrates scope.
Summary
One of the considerations when a child presents with paroxysmal events is psychogenic nonepileptic seizures (PNES). PNES are discernible changes in behavior or consciousness that resemble ...epileptic seizures but are not accompanied by electrophysiologic changes. They are usually understood as the manifestation of a conversion disorder that reflects underlying psychological distress. There is a lack of population‐based data on the prevalence or incidence of PNES in pediatric populations. The prevalence of PNES in children would appear to be lower than that in the adult population, but the prevalence of PNES seems to increase with age, and nonepileptic paroxysmal events are more likely to be PNES in adolescence than earlier in childhood. In terms of manifestation, PNES in childhood have been described using various categorizations and terminology, making comparisons across studies difficult. There is some evidence that events are more likely to involve unresponsiveness in younger children and prominent motor symptoms in older children. The most common precipitating factors would appear to be school‐related difficulties and interpersonal conflict within the child's family. In terms of psychopathology, children with PNES are at high risk for symptoms of depression and anxiety. Accurate diagnosis of PNES in children is likely to involve taking a comprehensive description of the episodes, garnering the child's medical/developmental history, video‐electroencephalography (video‐EEG) to rule out epileptic seizures, and an evaluation of family functioning. The importance of effective and sensitive communication of the diagnosis of PNES has been emphasized and management approaches will typically involve multidisciplinary efforts to safely manage the events at home and at school. Interventions to reduce the effect of precipitating psychosocial stressors and the involvement of a mental health professional to treat comorbid psychopathology will also form part of an effective management plan. Outcome at follow‐up is reported to be largely positive, although studies have not been able to follow all children, and few studies have focused on predictors of a good outcome. Future controlled intervention studies using a range of outcome measures are needed to identify efficacious approaches and predictors of best outcome.
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