Search results for "TOXICOLOGY"
showing 10 items of 4114 documents
PTP1B phosphatase as a novel target of oleuropein activity in MCF-7 breast cancer model.
2019
Phosphatase PTP1B has become a therapeutic target for the treatment of type 2-diabetes, whereas recent studies have revealed that PTP1B plays a pivotal role in pathophysiology and development of breast cancer. Oleuropein is a natural, phenolic compound with anticancer activity. The aim of this study was to address the question whether PTP1B constitutes a target for oleuropein in breast cancer MCF-7 cells. The cellular MCF-7 breast cancer model was used in the study. The experiments were performed using cellular viability tests, Elisa assays, immunoprecipitation, flow cytometry analyses and computer modelling. Herein, we evidenced that the reduced activity of phosphatase PTP1B after treatmen…
Toxicity and cell density monitoring in monolayer and three-dimensional cultures with the XTT assay
1998
The application of viability criteria (MTT and XTT tests) to monolayer cultures and immobilised cells in three-dimensional systems was investigated in order to assess cell viability and cell proliferation. The suitability and accuracy of these tests were compared with the conventional criteria (cellular protein and DNA content) used in monolayer cultures for the same purpose. The colorimetric assay based on the metabolic reduction of the tetrazolium salt XTT to a water-soluble formazan proved to be very useful, rapid and sensitive. This automated spectrophotometric enzymatic method, due to its lack of toxicity, also permits repeated nondestructive assays on a single cellular culture for the…
The Double-Edged Sword Profile of Redox Signaling: Oxidative Events As Molecular Switches in the Balance between Cell Physiology and Cancer.
2018
The intracellular redox state in the cell depends on the balance between the level of reactive oxygen species (ROS) and the activity of defensive systems including antioxidant enzymes. This balance is a dynamic process that can change in relation to many factors and/or stimuli induced within the cell. ROS production is derived from physiological metabolic events. For instance, mitochondria represent the major ROS sources during oxidative phosphorylation, but other systems, such as NADPH oxidase or specific enzymes in certain metabolisms, may account for ROS production as well. Whereas high levels of ROS perturb the cell environment, causing oxidative damage to biological macromolecules, low…
Enniatin B induces expression changes in the electron transport chain pathway related genes in lymphoblastic T-cell line
2018
Abstract Enniatin B is a ionophoric and lipophilic mycotoxin which reaches the bloodstream and has the ability to penetrate into cellular membranes. The purpose of this study was to reveal changes in the gene expression profile caused by enniatin B in human Jurkat lymphoblastic T-cells after 24 h of exposure at 1.5, 3 and 5 μM by next generation sequencing. It was found that up to 27% of human genome expression levels were significantly altered (5750 genes for both down-regulation and up-regulation). In the three enniatin B concentrations studied 245 differentially expressed genes were found to be overlapped, 83 were down and 162 up-regulated. ConsensusPathDB analysis of over-representation…
Grey Matter Microstructural Integrity Alterations in Blepharospasm Are Partially Reversed by Botulinum Neurotoxin Therapy.
2016
OBJECTIVE Benign Essential Blepharospasm (BEB) and hemifacial spasm (HFS) are the most common hyperkinetic movement disorders of facial muscles. Although similar in clinical presentation different pathophysiological mechanisms are assumed. Botulinum Neurotoxin (BoNT) is a standard evidence-based treatment for both conditions. In this study we aimed to assess grey matter microstructural differences between these two groups of patients and compared them with healthy controls. In patients we furthermore tracked the longitudinal morphometric changes associated with BoNT therapy. We hypothesized microstructural differences between the groups at the time point of maximum symptoms representation a…
Characterization of myofibroblasts isolated from the intestine of patients with inflammatory bowel disease
2019
Background: Intestinal fibrosis represents a serious complication of inflammatory bowel diseases (IBD), often necessitating surgical resections. Myofibroblasts are primarily responsible for interstitial matrix accumulation in fibrotic diseases. However intestinal myofibroblasts (IMF) remain inadequately characterized. The aim was to examine fibroblast markers and fibrosis-associated gene expression in IMF isolated from resected intestine from IBD and control patients. As well as determining the effect of the fibrogenic cytokine TGFβ. Methods: Intestinal resections were obtained (n =35) from consenting patients undergoing elective surgery (2014-16). Primary cultures of IMF were isolated usi…
Liquid chromatography-ultraviolet detection and quantification of heat-labile toxin produced by enterotoxigenic E. coli cultured under different cond…
2017
Abstract Enterotoxigenic Escherichia coli (ETEC) is the main bacterial cause of dehydrating infant diarrhoea in less-developed countries. Labile toxin (LT) is the major virulent factor of ETEC. Easy diagnostic tests are necessary to reduce the number of cases. Immunological methods have some drawbacks and also have important limitations. For that reason, a Liquid Chromatography coupled to UV detector technique (LC-UV) has been optimize to a rapid identification and quantification of LT from bacteria cultures. It is also important to know optimal conditions for LT and with this purpose several enterotoxigenic E. coli strains have been studied to determine the influence of glucose concentrati…
Tumor- and cytokine-primed human natural killer cells exhibit distinct phenotypic and transcriptional signatures.
2019
An emerging cellular immunotherapy for cancer is based on the cytolytic activity of natural killer (NK) cells against a wide range of tumors. Although in vitro activation, or "priming," of NK cells by exposure to pro-inflammatory cytokines, such as interleukin (IL)-2, has been extensively studied, the biological consequences of NK cell activation in response to target cell interactions have not been thoroughly characterized. We investigated the consequences of co-incubation with K562, CTV-1, Daudi RPMI-8226, and MCF-7 tumor cell lines on the phenotype, cytokine expression profile, and transcriptome of human NK cells. We observe the downregulation of several activation receptors including CD…
Oxidative damage and disturbance of antioxidant capacity by zearalenone and its metabolites in human cells.
2017
Mycotoxin contamination of foods and feeds represent a serious problem worldwide. Zearalenone (ZEA) is a secondary metabolite produced by Fusarium species. This study explores oxidative cellular damage and intracellular defense mechanisms (enzymatic and non-enzymatic) in the hepatoma cell line HepG2 after exposure to ZEA and its metabolites (α-zearalenol, α-ZOL; β-zearalenol, β-ZOL). Our results demonstrated that HepG2 cells exposed to ZEA, α-ZOL or β-ZOL at different concentrations (0, 6.25, 12.5 and 25μM) showed: (i) elevated ROS levels (1.5- to 7-fold) based on the formation of the highly fluorescent 2',7'-dichlorofluorescein (DCF), (ii) increased DNA damage measured by the comet assay (…
In Vitro Study of the Cytotoxic, Cytostatic, and Antigenotoxic Profile of Hemidesmus indicus (L.) R.Br. (Apocynaceae) Crude Drug Extract on T Lymphob…
2018
In traditional Indian medicine, the crude drug Hemidesmus indicus rootâcommonly known as Indian sarsaparillaâis used alone or in poly-herbal preparations for the treatment of a wide range of diseases. The present study focuses on the cancer chemopreventive and therapeutic potential of H. indicus extracts on an acute lymphoblastic leukemia cell line (CCRF-CEM). With this aim in mind, we subjected H. indicus roots to two subsequent extractions (hydro-alcoholic extraction and soxhlet extraction). As DNA damage is an important prerequisite for the induction of mutations/cancer by genotoxic carcinogens, cancer chemoprevention may be achieved by preventing genotoxicity. Through an integrated …