The MTT assay is widely used in cell proliferation and cytotoxicity assays. Most cellular bioreduction of MTT is associated with enzymes of the endoplasmic reticulum and involves the reduced pyridine nucleotides NADH and, to a lesser extent, NADPH. Succinate is a weak electron donor for mitochondrial MTT reduction. Recently, new tetrazolium salt assays that use intermediate electron acceptors to facilitate reduction have been introduced. In this article, we compare the biochemical basis of reduction of MTT, XTT, and WST-1. Unlike MTT, XTT and WST-1 are efficiently reduced by NADH and NADPH in the absence of cells or enzymes, and their reduction involves superoxide. Cellular reduction of WST-1 occurs at the cell surface and also involves superoxide.
: Microculture tetrazolium assays (MTAs) are being widely applied to probe the relationships between cell survival, growth, and differentiation and also to investigate associations between compromised cell metabolism, oxidative stress, and programmed cell death as occurs in apoptosis. MTAs rely upon the cellular reduction of tetrazolium salts to their intensely coloured formazans. The resulting colorimetric assays form the basis of exceptionally precise systems which are technically amenable and...
Last. An S. Tan(Malaghan Institute of Medical Research)H-Index: 16
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Hemopoietic cell proliferation is controlled by a set of polypeptide growth factors and regulatory molecules that bind to cell surface receptors inducing cellular responses. Maintenance of a viable state, cell growth, DNA synthesis and mitosis are basic properties of proliferating cells, but links between growth factor receptors and each of these cellular outcomes are poorly understood. Most studies have monitored DNA synthesis as a measure of progression through the cell cycle or directly measu...
Abstract Glucose oxidase reduces nitroblue tetrazolium, or ferricytochrome c, faster anaerobically thari aerobically. This result is inconsistent with the conclusion that GO2 can reduce O2 to O−2 which is then responsible for the reduction of NET and of cytochrome c. Nevertheless, the aerobic reductions are partially inhibitable by superoxide dismutase. A scheme of reactions is proposed which explains why these electron acceptors cause an O−2 production which does not occur in their absence when...
Abstract The MTT assay, which is widely used to measure cell proliferation and to screen for anticancer drugs, is based on reduction of the tetrazolium salt, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) by actively growing cells to produce a blue formazan product. Despite broad acceptance of this assay, neither the subcellular localization, nor the biochemical events involved in MTT reduction are known. Mitochondrial involvement in MTT reduction has been inferred from studi...
: Hemopoietic growth factors promote cell survival, proliferation and differentiation, but whether these processes, which often occur in concert, are mediated through the same or different receptor signaling mechanisms is not known. Using the bone marrow-derived IL-3-dependent cell line, 32D, we show that dibutyryl cyclic adenosine monophosphate (dbcAMP) retards the rapid loss of viable cells seen in the absence of IL-3. This effect is shown to be concentration-dependent and detectable within 16...
Abstract The hydrogen acceptor 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) is commonly utilized to estimate cellular viability in drug screening protocols. The present investigation was prompted, in part, by observations that reduction of MTT to its colored reaction product, MTT formazan, varied between cell lines and with culture age. A correlation was established between the d-glucose concentration of the culture medium at the time of assay and the production of MTT form...
Abstract In aerobic reaction mixtures containing NADH, phenazine methosulf ate, and nitroblue tetrazolium, O 2 − production is mediated by the tetrazolium, not the phenazine. Thus, superoxide dismutase inhibited reduction of the tetrazolium, but when ferricytochrome c was substituted for the tetrazolium its reduction was not affected by this enzyme. Furthermore, NADH plus the phenazine did not accelerate the oxidation of epinephrine to adrenochrome unless the tetrazolium was present, and under t...
Abstract A tetrazolium salt has been used to develop a quantitative colorimetric assay for mammalian cell survival and proliferation. The assay detects living, but not dead cells and the signal generated is dependent on the degree of activation of the cells. This method can therefore be used to measure cytotoxicity, proliferation or activation. The results can be read on a multiwell scanning spectrophotometer (ELISA reader) and show a high degree of precision. No washing steps are used in the as...
A. G. E. Pearse is a relative newcomer to the field of histochemistry. He holds an M.D. degree from the University of Cambridge and is now Lecturer in Histochemistry at the Postgraduate Medical School, University of London. One of his first contributions to histochemistry consisted of a critical review of its methodology and interpretation, written for pathologists and appearing in the British Journal of Clinical Pathology 4: 1 (1951). He has also introduced a number of new or modified technique...
Last. Alexandre Havt(UFC: Federal University of Ceará)H-Index: 28
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Abstract Objective Vitamin A is commonly recommended as a treatment for diarrhea and undernutrition; however, little is known about the underlying cellular mechanisms. The aim of this study was to investigate the modulation of cell cycle by vitamin A derivatives (retinyl palmitate or retinol) in undernourished intestinal epithelial crypts (IEC-6). Methods IEC-6 cells were exposed to nutrient deprivation (no serum and no glutamine) and supplemented with retinyl palmitate or retinol at a range of ...
Last. Ronaldo N. de Oliveira(UFRPE: Universidade Federal Rural de Pernambuco)H-Index: 10
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Abstract A total of forty-three compounds were synthesized, including thirty-two new ones. Among those compounds, seventeen were selected and tested on human tumor cell lines: PC-3 (prostate adenocarcinoma), HCT-116 (colorectal tumor), NCIH-460 (lung carcinoma), SKMEL-103 (melanoma) and AGP-01 (gastric tumor). Alkynylated 1,2,4-oxadiazoles 2m, 3g and 3k exhibited antiproliferative activities against NCIH-460 in culture. Alkynylated N-cyclohexyl-1,2,4-oxadiazoles 3a-m and bis-heterocycle glucogly...
Last. Amirhossein Sahebkar(MUMS: Mashhad University of Medical Sciences)H-Index: 104
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Atherosclerosis is one type of cardiovascular disease (CVD) in which activation of the NLRP3 inflammasome and toll-like receptor (TLR) pathways is implicated. One of the most effective treatments for atherosclerosis is the use of statin medications. Recent studies have indicated that statins, in addition to their lipid-lowering effects, exert inhibitory and/or stimulatory effects on the NLRP3 inflammasome and TLRs. Some of the statins lead to activation of the inflammasome and subsequently cause...
Lignans/neolignans are generally synthesized from coniferyl alcohol (CA) in the cinnamate/monolignol pathway by oxidation to generate the corresponding radicals with subsequent stereoselective dimerization aided by dirigent proteins (DIRs). Genes encoding oxidases and DIRs for neolignan biosynthesis have not been identified previously. In Arabidopsis thaliana, the DIR AtDP1/AtDIR12 plays an essential role in the 8-O-4' coupling in neolignan biosynthesis by unequivocal structural determination of...
#1Emile Roussel(CNRS: Centre national de la recherche scientifique)H-Index: 1
#2Alexis Moreno(CNRS: Centre national de la recherche scientifique)H-Index: 9
Last. Ahcène Boumendjel(CNRS: Centre national de la recherche scientifique)H-Index: 35
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Abstract The Breast Cancer Resistance Protein (BCRP/ABCG2) belongs to the G class of ABC (ATP-Binding Cassette) proteins, which is known as one of the main transporters involved in the multidrug resistance (MDR) phenotype that confer resistance to anticancer drugs. The aim of this study was to design, synthesize and develop new potent and selective inhibitors of BCRP that can be used to abolish MDR and potentialize clinically used anticancer agents. In previous reports, we showed the importance ...
Abstract Tetrahydrocurcumin (THC) is one of the major metabolites of curcumin (CUR), an ancient bioactive natural polyphenolic compound. This research article described both the solid and liquid state characterization of THC using advanced spectroscopic and thermo-analytical techniques. Anti-inflammatory, anti-oxidant, and neuroprotective activities of THC were investigated using in vitro cell lines. Liquid chromatography-mass spectrometry analysis revealed that our sample comprised of 95.15% TH...
AbstractA skin irritation test using in vitro reconstructed human epidermis (RhE) models was established for hazard identification of irritant chemicals in accordance with UN Globally Harmonized Sy...
The topic of titanium alloys for dental implants has been reviewed. The basis of the review was a search using PubMed, with the large number of references identified being reduced to a manageable number by concentrating on more recent articles and reports of biocompatibility and of implant durability. Implants made mainly from titanium have been used for the fabrication of dental implants since around 1981. The main alloys are so-called commercially pure titanium (cpTi) and Ti-6Al-4V, both of wh...
Abstract The aim of this work was to examine the behavior of conjugated linoleic acid (CLA) delivery systems based on ovalbumin (OVA) and their derived nanoparticles (OVAn1 and OVAn2), under static in vitro gastrointestinal digestion model. In addition, potential cytotoxic effect of these inclusion complexes on a human colon cancer cell line (HT-29) was evaluated. OVA was resistant to gastric and intestinal digestion, while OVA nanoparticles were very susceptible to digestive enzymes hydrolysis....
Abstract Natural and synthetic phenazines are widely used in biomedical sciences. In dehydrogenase histochemistry, phenazine methosulfate (PMS) is applied as a redox reagent for coupling reduced coenzymes to the reduction of tetrazolium salts into colored formazans. PMS is also currently used for cytotoxicity and viability assays of cell cultures using sulfonated tetrazoliums. Under UV (340 nm) excitation, aqueous solutions of the cationic PMS show green fluorescence (λem: 526 nm), whereas the r...