Search results for "Dox"
showing 10 items of 1345 documents
Chemistry and reactivity of dinuclear manganese oxamate complexes: Aerobic catechol oxidation catalyzed by high-valent bis(oxo)-bridged dimanganese(I…
2006
[EN] The high-valent bis(oxo)-bridged dimanganese(IV) complexes with the series of binucleating 4.5-X-2-o-phenylenebis(oxamate) ligands (opbaX(2); X = H, Cl, Me) (1a-c) have been synthesized and characterized structurally, spectroscopically and magnetically. Complexes la-c possess unique Mn-2(mu-O)(2) core structures with two o-phenylenediamidate type additional bridges which lead to exceptionally short Mn-Mn distances (2.63-2.65 angstrom) and fairly bent Mn-O-Mn angles (94.1 degrees-94.6 degrees). The cyclovoltammograms of la-c in acetonitrile (25 degrees C, 0.1 M Bu4NPF6) show an irreversible one-electron oxidation peak at moderately high anodic potentials (E-ap = 0.50-0.85 V versus SCE),…
Indicaxanthin inhibits NADPH oxidase (NOX)-1 activation and NF-κB-dependent release of inflammatory mediators and prevents the increase of epithelial…
2014
Dietary redox-active/antioxidant phytochemicals may help control or mitigate the inflammatory response in chronic inflammatory bowel disease (IBD). In the present study, the anti-inflammatory activity of indicaxanthin (Ind), a pigment from the edible fruit of cactus pear (Opuntia ficus-indica, L.), was shown in an IBD model consisting of a human intestinal epithelial cell line (Caco-2 cells) stimulated by IL-1β, a cytokine known to play a major role in the initiation and amplification of inflammatory activity in IBD. The exposure of Caco-2 cells to IL-1β brought about the activation of NADPH oxidase (NOX-1) and the generation of reactive oxygen species (ROS) to activate intracellular signal…
Identification of new P-glycoprotein inhibitors derived from cardiotonic steroids
2014
P-glycoprotein (ABCB1, MDR1) is capable of extruding chemotherapeutics outside the cell and its overexpression in certain cancer cells may cause failure of chemotherapy. Many attempts were carried out to identify potent inhibitors of this transporter and numerous compounds were shown to exert inhibitory effects in vitro, but so far none were able to make their way to the clinic due to serious complications. Natural compounds represent a great source of therapeutics, which are believed to be safe and effective. Therefore, we have screened a large library of naturally occurring cardiotonic steroids and their derivatives using high throughput flow cytometry. We were able to identify six compou…
Enzyme-Controlled Nanodevice for Acetylcholine-Triggered Cargo Delivery Based on Janus Au–Mesoporous Silica Nanoparticles
2017
[EN] This work reports a new gated nanodevice for acetylcholine-triggered cargo delivery. We prepared and characterized Janus Au-mesoporous silica nanoparticles functionalized with acetylcholinesterase on the Au face and with supramolecular b-cyclodextrin: benzimidazole inclusion complexes as caps on the mesoporous silica face. The nanodevice is able to selectively deliver the cargo in the presence of acetylcholine via enzyme-mediated acetylcholine hydrolysis, locally lowering the pH and opening the supramolecular gate. Given the key role played by ACh and its relation with Parkinson's disease and other nervous system diseases, we believe that these findings could help design new therapeuti…
Cell Culture Characterization of Prooxidative Chain-Transfer Agents as Novel Cytostatic Drugs
2021
Prooxidative therapy is a well-established concept in infectiology and parasitology, in which prooxidative drugs like artemisinin and metronidazole play a pivotal clinical role. Theoretical considerations and earlier studies have indicated that prooxidative therapy might also represent a promising strategy in oncology. Here, we have investigated a novel class of prooxidative drugs, namely chain-transfer agents, as cytostatic agents in a series of human tumor cell lines in vitro. We have found that different chain-transfer agents of the lipophilic thiol class (like dodecane-1-thiol) elicited half-maximal effective concentrations in the low micromolar range in SY5Y cells (human neuroblastoma)…
Cytotoxicity, anti-angiogenic, apoptotic effects and transcript profiling of a naturally occurring naphthyl butenone, guieranone A
2012
Abstract Background Malignant diseases are responsible of approximately 13% of all deaths each year in the world. Natural products represent a valuable source for the development of novel anticancer drugs. The present study was aimed at evaluating the cytotoxicity of a naphtyl butanone isolated from the leaves of Guiera senegalensis, guieranone A (GA). Results The results indicated that GA was active on 91.67% of the 12 tested cancer cell lines, the IC50 values below 4 μg/ml being recorded on 83.33% of them. In addition, the IC50 values obtained on human lymphoblastic leukemia CCRF-CEM (0.73 μg/ml) and its resistant subline CEM/ADR5000 (1.01 μg/ml) and on lung adenocarcinoma A549 (0.72 μg/m…
EngineeredControl of Cell Morphology In Vivo Reveals Distinct Roles for Yeast andFilamentous Forms of Candida albicans duringInfection
2003
ABSTRACT It is widely assumed that the ability of Candida albicans to switch between different morphologies is required for pathogenesis. However, most virulence studies have used mutants that are permanently locked into either the yeast or filamentous forms which are avirulent but unsuitable for discerning the role of morphogenetic conversions at the various stages of the infectious process. We have constructed a strain in which this developmental transition can be externally modulated both in vitro and in vivo. This was achieved by placing one copy of the NRG1 gene (a negative regulator of filamentation) under the control of a tetracycline-regulatable promoter. This modified strain was th…
Resveratrol reduces oxidative stress and cell death and increases mitochondrial antioxidants and XIAP in PC6.3-cells.
2010
Resveratrol, a polyphenol derived e.g. from red grapes, has been shown to mediate several positive biological actions such as protection of cells against oxidative stress. It can also influence cell signaling, but the mechanisms behind its antioxidant properties are largely unknown. Here we show that RSV reduces oxidative stress and enhances cell survival in PC6.3 cells depending on the concentration. In these cells, RSV increased the levels of antioxidants, SOD2 and TRX2, and of X chromosome-linked inhibitor of apoptosis protein. RSV also activated NFκB signaling as shown using luciferase reporter constructs. These findings show that RSV regulates oxidative stress and mitochondrial antioxi…
Lafora disease fibroblasts exemplify the molecular interdependence between thioredoxin 1 and the proteasome in mammalian cells
2013
13 páginas, 8 figuras (que no aparecen en este documento, se pueden consultar en: http://www.sciencedirect.com/science/article/pii/S0891584913003274#ec0005)
Powerful tumor cell growth-inhibiting activity of a synthetic derivative of atractyligenin: Involvement of PI3K/Akt pathway and thioredoxin system
2014
The semi-synthetic ent-kaurane 15-ketoatractyligenin methyl ester (SC2017) has been previously reported to possess high antiproliferative activity against several solid tumor-derived cell lines. Our study was aimed at investigating SC2017 tumor growth-inhibiting activity and the underlying mechanisms in Jurkat cells (T-cell leukemia) and xenograft tumor models. METHODS: Cell viability was evaluated by MTT assay. Cell cycle progression, reactive oxygen species (ROS) elevation and apoptotic hallmarks were monitored by flow cytometry. Inhibition of thioredoxin reductase (TrxR) by biochemical assays. Levels and/or activation status of signaling proteins were assessed by western blotting. Xenogr…