Search results for "toxicity."
showing 10 items of 2180 documents
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…
Antitumoural properties of benzannelated seven-membered 5-fluorouracil derivatives and related open analogues. Molecular markers for apoptosis and ce…
2005
Attention is increasingly being focussed on the cell cycle and apoptosis as potential targets for therapeutic intervention in cancer. We prepared a series of bioisosteric benzannelated seven-membered 5-FU O,N-acetals to test them against the MCF-7 human breast cancer cell line. Benzo-fused seven-membered O,O-acetals or their acyclic analogues led to the expected 5-FU O,N-acetals (or aminals), in addition to six- and 14-membered aminal structures and acyclic compounds. All the cyclic aminals provoked a G0/G1-phase cell cycle arrest, whereas Ftorafur, a known prodrug of 5-FU, and 1-[2-(2-hydroxymethyl-4-nitrophenoxy)-1-methoxyethyl]-5-fluorouracil (11) induced an S-phase cell cycle arrest. Al…
Lanostanoids from fungi: a group of potential anticancer compounds.
2012
Lanostanes are a group of tetracyclic triterpenoids derived from lanosterol. They have relevant biological and pharmacological properties, such as their cytotoxic effects via induction of apoptosis. This review compiles the most relevant lanostanoids studied from 2000 to 2011, principally those isolated from Ganoderma lucidum and other related fungi, such as Poria cocos, Laetiporus sulphureus, Inonotus obliquus, Antrodia camphorata, Daedalea dickinsii, and Elfvingia applanata, which have great potential as anticancer agents because of their cytotoxic or apoptotic effects. The compounds were selected on the basis of their proapoptotic mechanisms, through their ability to modify transcription…
Induction of secondary cytotoxic T-lymphocytes in vitro does not require cell proliferation.
1976
SummaryUsing a mouse in vitro allograft model, evidence has been obtained that, in contrast to the accepted view, the generation of cytotoxic effector function in T-lymphocytes does not necessarily require cell division.
Antitumor effects of curcumin and structurally β-diketone modified analogs on multidrug resistant cancer cells
2007
Abstract Using concepts of bioisostery a series of curcumin analogs were synthesized: the diketonic system of the compound was elaborated into enaminones, oximes, and the isoxazole heterocycle. The cell growth inhibitory and apoptosis inducing effects of the new analogs were evaluated by in vitro assays in the hepatocellular carcinoma HA22T/VGH cells, as well as in the MCF-7 breast cancer cell line and in its multidrug resistant (MDR) variant MCF-7R. Increased antitumor activity on all cell lines was found with the isoxazole analog and especially with the benzyl oxime derivative; in the HA22T/VGH cell model, the latter compound inhibited constitutive NF-κB activation.
Cytotoxicity and dentin composition alterations promoted by different chemomechanical caries removal agents : a preliminary in vitro study
2021
Background The use of chemomechanical agents for caries removal has been indicated as a non-invasive treatment option; however, their possible deleterious effects on the dental-pulp complex have been insufficiently studied. This study assessed the direct cytotoxicity of two chemomechanical caries removal agents (Brix 3000™ - BX and Papacarie Duo™ - PD) on pulp cells from deciduous teeth, as well as to assess the morphology and chemical compositions of the dentin surface after the application of these materials. Material and methods The cells were seeded (50,000 cells/cm²) in a culture medium (DMEM with 10% fetal bovine serum - FBS). After 24 hours, the BX and PD materials were added to 1:20…
Transcriptional study after Beauvericin and Enniatin B combined exposure in Jurkat T cells
2019
Simultaneous mycotoxins toxicity is complex and non-predictable based on their individual toxicities. Beauvericin and Enniatins are emerging mycotoxins highly co-occurrent in food and feed, and their cytotoxicity has been reported in several human cell lines. RNA-seq studies of individual exposure in Jurkat cells demonstrated human genome perturbation mainly affecting mitochondrial pathways, however, both mycotoxins showed differences between their toxic responses. This study investigates the transcriptional effects of combined exposure to Beauvericin and Enniatin B (1:1) (0.1, 0.5, 1.5 μM; 24 h) in Jurkat cells by qPCR on 30 selected target genes (10 mitochondrial, 20 nuclear). Gene expres…
Pyridinedicarboxylates, the first mechanism-derived inhibitors for prolyl 4-hydroxylase, selectively suppress cellular hydroxyprolyl biosynthesis. De…
1987
Two pyridinedicarboxylates, predicted [Hanauske-Abel (1983) M.D.-Ph.D. Thesis, Philipps Universität Marburg] and later found to be potent reversible inhibitors of purified prolyl 4-hydroxylase [Majaama, Hanauske-Abel, Günzler & Kivirikko (1984) Eur. J. Biochem. 138, 239-245] were investigated with respect to their effect on hydroxyprolyl biosynthesis in the fibroblast/collagen and the macrophage/Clq systems, and the effect was compared with that of the iron chelator 2,2′-dipyridyl, the compound usually employed to inhibit cellular hydroxyprolyl formation. Only the enzyme-mechanism-derived pyridinedicarboxylates were highly selective inhibitors, and only they lacked overt cytotoxicity. M…
MOLECULAR BASIS OF DRUG PHOTOTOXICITY: PHOTOSENSITIZED CELL DAMAGE BY THE MAJOR PHOTOPRODUCT OF TIAPROFENIC ACID
1994
Tiaprofenic acid is a photosensitizing nonsteroidal anti-inflammatory drug, whose major photoproduct (decarboxytiaprofenic acid) is also a potent photosensitizer. Because of the lack of the carboxylate moiety, this photoproduct is more lipophilic and might bind more efficiently to cell membranes, thereby causing phototoxic damage. To verify the feasibility of this hypothesis, we have prepared the 3H-labeled analogs of tiaprofenic acid and its photoproduct and examined the binding, persistence and phototoxicity of the photoproduct using poorly metabolizing (fibroblasts) and actively metabolizing cells (hepatocytes). The photoproduct of tiaprofenic acid accumulates in both cell types as it is…
Design of enzyme-mediated controlled release systems based on silica mesoporous supports capped with ester-glycol groups
2012
[EN] An ethylene glycol-capped hybrid material for the controlled release of molecules in the presence of esterase enzyme has been prepared. The final organic-inorganic hybrid solid S1 was synthesized by a two-step procedure. In the first step, the pores of an inorganic MCM-41 support (in the form of nanoparticles) were loaded with [Ru(bipy) 3]Cl 2 complex, and then, in the second step, the pore outlets were functionalized with ester glycol moieties that acted as molecular caps. In the absence of an enzyme, release of the complex from aqueous suspensions of S1 at pH 8.0 is inhibited due to the steric hindrance imposed by the bulky ester glycol moieties. Upon addition of esterase enzyme, del…