Search results for "Survival"
showing 10 items of 3291 documents
Cytotoxicity of 40 Egyptian plant extracts targeting mechanisms of drug-resistant cancer cells
2019
Abstract Background The multidrug resistance (MDR) phenotype encounters a major challenge to the success of established chemotherapy in cancer patients. We hypothesized that cytotoxic medicinal plants with novel phytochemicals can overcome MDR and kill MDR-cells with similar efficacy as drug sensitive cells. Purpose We evaluated plant extracts from an unexplored ecosystem in Egypt with unusual climate and nutrient conditions for their activity against sensitive and multidrug-resistant cancer cell lines. Material and methods/study design Methylene chloride: methanol (1:1) and methanol: H2O (7:3) extracts of 40 plants were prepared resulting in a sum of 76 fraction containing compounds with v…
Resveratrol metabolites inhibit human metastatic colon cancer cells progression and synergize with chemotherapeutic drugs to induce cell death.
2012
Scope Resveratrol (RSV) has been proposed to prevent tumor growth; nevertheless, these preventive effects are controversial since RSV pharmacokinetics studies show a low bioavailability. Recent clinical trials show that patients with colorectal cancer and receiving oral RSV have high levels of RSV conjugates in the colorectum, mainly RSV-3-O-sulfate (R3S), RSV-3-O-glucuronide, and RSV-4′-O-glucuronide. However, their potential biological activity has not yet been established. This study thus investigated in human colorectal cancer cell lines whether RSV main metabolites retain anticarcinogenic properties as their parental molecule. Methods and results Proliferation, apoptosis assays and cel…
Comparative analysis of stress responses of H9c2 rat cardiomyoblasts following treatment with doxorubicin and tBOOH
2011
Abstract Cardiotoxicity is the major dose-limiting adverse effect of anthracyclines and is hypothesized to result from damage induced by reactive oxygen species (ROS) or inhibition of topoisomerase II. Here, we comparatively analyzed the effect of doxorubicin and the organic peroxide tertiary-butylhydroperoxide (tBOOH) on stress responses of rat cardiomyblast cells (H9c2). Moreover, we investigated the impact of serum factors and the novel prototypical protein kinase CK2 inhibitor resorufin on the sensentivity of H9c2 cells exposed to doxorubicin or tBOOH. Measuring cell viability by use of the WST assay as well as cell cycle progression and apoptotic death by FACS-based methods, we found t…
Characterization of cells with different mitochondrial membrane potential during apoptosis.
2005
Background Until now, the simultaneous analysis of several parameters during apoptosis, including DNA content and mitochondrial membrane potential (ΔΨ), has not been possible because of the spectral characteristics of the commonly used dyes. Using polychromatic flow cytometry based upon multiple laser and UV lamp excitation, we have characterized cells with different ΔΨ during apoptosis. Methods U937 cells were treated with the flavonoid quercetin (Qu) and stained with JC-1 to detect ΔΨ, propidium iodide (PI) for cell viability, Hoechst 33342 for DNA content, Annexin V conjugated with Alexa Fluor-647 for detection of phosphatidilserine (PS) exposure, marker of early apoptosis, or Mitotracke…
A novel pro-apoptotic role of zinc octacarboxyphthalocyanine in melanoma me45 cancer cell's photodynamic therapy (PDT)
2018
Abstract Zn-based phthalocyanine acts as drug or photosensitizer in photodynamic therapy (PDT) for the treatment of cancer cells. The activated zinc octacarboxyphthalocyanine (ZnPcOC) reacts with oxygen, to generate reactive oxygen species for the damage of melanoma cancer cells, Me45. This in vitro study aimed at investigating the cytotoxic effects of different concentrations of ZnPcOC activated with a diode laser (λ = 685 nm) on Me45, and normal human fibroblast cells, NHDF. To perform this study 104 cells/ml were seeded in 96-well plates and allowed to attach overnight, after which cells were treated with different concentrations of ZnPcOC (10, 20 and 30 μM). After 4 h, cells were irradi…
Cytotoxicity and induction of DNA double-strand breaks by components leached from dental composites in primary human gingival fibroblasts
2012
Abstract Introduction The public interest steadily increases in the biological adverse effects caused by components released from resin-based dental restorations. Objective In this study, the cytotoxicity and the genotoxicity were investigated of following released components from dental resin restorations in human gingival fibroblasts (HGF): tetraethyleneglycol dimethacrylate (TEEGDMA), neopentylglycol dimethacrylate (Neopen), diphenyliodoniumchloride (DPIC), triphenyl-stibane (TPSB) and triphenylphosphane (TPP). Methods XTT based cell viability assay was used for cytotoxicity screening of substances. γ-H2AX assay was used for genotoxicity screening. In the γ-H2AX assay, HGFs were exposed …
Excitotoxin-induced changes in transglutaminase during differentiation of cerebellar granule cells
2002
Excitotoxicity induced by NMDA receptor stimulation is able to increase the activity of many enzymes involved in neuronal cell death. Primary cultures of rat cerebellar granule cells were used to elucidate the role of transglutaminase reaction in the excitotoxic cell response, and to evaluate the role of glutamate receptors in cell survival and degeneration. Granule neurons, maintained in vitro for two weeks, were exposed to NMDA at different stages of differentiation. Following NMDA receptor activation, increases in transglutaminase activity were observed in cell cultures. The levels of enzyme activity were higher in cells at 5 days in vitro than in those at 8-9 or 13-14 days in vitro. Mor…
Apoptosis of T cells and the control of inflammatory bowel disease: therapeutic implications.
2007
Inflammatory bowel diseases (IBDs) such as Crohn’s disease and ulcerative colitis are the result of an imbalanced mucosal T cell response. Despite the identification of a genetic susceptibility region in the NOD2/CARD15 (nucleotide-binding oligomerisation domain 2/caspase recruitment domain 15) gene, the aetiology is still unclear. Thus, the hunt for disease-initiating factors such as defects in the mucosal barrier or pathogenic microorganisms is ongoing. By contrast, the immunopathogenesis in IBDs is better understood. The identification of cytokines that are involved in T cell and monocyte signalling led to specific therapeutic concepts. Recent data have clearly shown that the most powerf…
Absence of correlation between oxysterol accumulation in lipid raft microdomains, calcium increase, and apoptosis induction on 158N murine oligodendr…
2013
There is some evidence that oxidized derivatives of cholesterol, 7-ketocholesterol (7KC) and 7β-hydroxycholesterol (7βOHC), are increased in the plasma of patients with neurodegenerative diseases associated with demyelinization of the central nervous system (CNS). It was therefore of interest to investigate the effects of these oxysterols on oligodendrocytes, the myelin-forming cells in the CNS. To this end, 158N murine oligodendrocytes were treated with 7KC or 7βOHC inducing an apoptotic mode of cell death characterized by condensation/fragmentation of the nuclei, dephosphorylation of Akt and GSK3, mitochondrial depolarization involving Mcl-1, and caspase-3 activation. In contrast, under t…
Studies on the subcellular pathophysiology of acute lethal cell injury.
1974
Summary In this paper we have summarized the effects of acute lethal injury on the cell. Such injuries are defined as injuries that result in cell death within a relatively short period of time usually minutes or hours. Following death; the cell undergoes necrosis. Ultrastructural and biochemical methods are needed to study pathophysiology. The cell passes through a series of stages numbered 1 through 7. Stages 1 through 4 are reversible while 5 through 7 are irreversible. Injuries resulting in acute cell death and necrosis include direct damage to the cell membrane, for example by antibody and complement or non-penetrating mercurials or interference with mitochondrial energy supply as in i…