EFFECT OF ELEVATED TEMPERATURE, DARKNESS, AND HYDROGEN PEROXIDE TREATMENT ON OXIDATIVE STRESS AND CELL DEATH IN THE BLOOM-FORMING TOXIC CYANOBACTERIUM MICROCYSTIS AERUGINOSA1

2011 ◽  
Vol 47 (6) ◽  
pp. 1316-1325 ◽  
Author(s):  
Josée N. Bouchard ◽  
Duncan A. Purdie
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Cell Death ◽  
Elevated Temperature ◽  
Toxic Cyanobacterium ◽  
Hydrogen Peroxide Treatment

Epicatechin and its in vivo metabolite, 3′-O-methyl epicatechin, protect human fibroblasts from oxidative-stress-induced cell death involving caspase-3 activation

2001 ◽  
Vol 354 (3) ◽  
pp. 493-500 ◽  
Author(s):  
Jeremy P. E. SPENCER ◽  
Hagen SCHROETER ◽  
Gunter KUHNLE ◽  
S. Kaila S. SRAI ◽  
Rex M. TYRRELL ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Cell Death ◽  
Caspase 3 ◽  
Cell Damage ◽  
Protective Action ◽  
Human Fibroblasts ◽  
Membrane Damage ◽  
Antioxidant Properties

There is considerable current interest in the cytoprotective effects of natural antioxidants against oxidative stress. In particular, epicatechin, a major member of the flavanol family of polyphenols with powerful antioxidant properties in vitro, has been investigated to determine its ability to attenuate oxidative-stress-induced cell damage and to understand the mechanism of its protective action. We have induced oxidative stress in cultured human fibroblasts using hydrogen peroxide and examined the cellular responses in the form of mitochondrial function, cell-membrane damage, annexin-V binding and caspase-3 activation. Since one of the major metabolites of epicatechin in vivo is 3′-O-methyl epicatechin, we have compared its protective effects with that of epicatechin. The results provide the first evidence that 3′-O-methyl epicatechin inhibits cell death induced by hydrogen peroxide and that the mechanism involves suppression of caspase-3 activity as a marker for apoptosis. Furthermore, the protection elicited by 3′-O-methyl epicatechin is not significantly different from that of epicatechin, suggesting that hydrogen-donating antioxidant activity is not the primary mechanism of protection.

scholarly journals Effects of Carbazole Derivatives on Neurite Outgrowth and Hydrogen Peroxide-Induced Cytotoxicity in Neuro2a Cells

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1366 ◽  
Author(s):  
Yoshiko Furukawa ◽  
Atsushi Sawamoto ◽  
Mizuki Yamaoka ◽  
Makiko Nakaya ◽  
Yuhzo Hieda ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Cell Death ◽  
Neurite Outgrowth ◽  
Akt Signaling ◽  
Akt Signaling Pathway ◽  
Anti Oxidant ◽  
Neuro2a Cells ◽  
Cerebral Ischemic

Many studies have demonstrated that oxidative stress plays an important role in several ailments including neurodegenerative diseases and cerebral ischemic injury. Previously we synthesized some carbazole compounds that have anti-oxidant ability in vitro. In this present study, we found that one of these 22 carbazole compounds, compound 13 (3-ethoxy-1-hydroxy-8- methoxy-2-methylcarbazole-5-carbaldehyde), had the ability to protect neuro2a cells from hydrogen peroxide-induced cell death. It is well known that neurite loss is one of the cardinal features of neuronal injury. Our present study revealed that compound 13 had the ability to induce neurite outgrowth through the PI3K/Akt signaling pathway in neuro2a cells. These findings suggest that compound 13 might exert a neurotrophic effect and thus be a useful therapy for the treatment of brain injury.

Morphogenic protein epimorphin protects intestinal epithelial cells from oxidative stress by the activation of EGF receptor and MEK/ERK, PI3 kinase/Akt signals

2007 ◽  
Vol 292 (1) ◽  
pp. G39-G52 ◽  
Author(s):  
Masahiro Iizuka ◽  
Kenji Sasaki ◽  
Yohei Hirai ◽  
Kenichi Shindo ◽  
Shiho Konno ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Cell Death ◽  
Epithelial Cells ◽  
Egf Receptor ◽  
Intestinal Epithelial Cells ◽  
Pi3 Kinase ◽  
Intestinal Epithelial ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal

Epimorphin is a mesenchymal protein that regulates morphogenesis of epithelial cells. Our preliminary study suggested a novel function of epimorphin in enhancing survival of intestinal epithelial cells (IEC). Oxidative stress leads to cell injury and death and is suggested to be a key contributor to pathogenesis of inflammatory bowel disease. This study was conducted to determine whether epimorphin protects IEC from oxidative stress. Rat intestinal epithelial cell line IEC-6 was cultured with epimorphin (10 and 20 μg/ml), and the life span of IEC was assessed. The mean life span of IEC-6 cells was prolonged 1.9-fold ( P < 0.0006) by treatment with epimorphin. We then examined the epimorphin signaling pathways. Epimorphin phosphorylated epidermal growth factor (EGF) receptor, activated the MEK/extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase and phosphatidylinositol 3 (PI3) kinase/Akt pathways, phosphorylated Bad, and induced Bcl-XL and survivin. Hydrogen peroxide (1 mM) induced cell death in 92% of IEC-6 cells, but epimorphin dramatically diminished (88.7%) cell death induced by hydrogen peroxide ( P < 0.0001). This protective effect of epimorphin was significantly attenuated by inhibitors of MEK and PI3 kinase ( P < 0.0001) or EGF receptor-neutralizing antibody ( P = 0.0007). In wound assays, the number of migrated cells in the wound area decreased (72.5%) by treatment with 30 μM hydrogen peroxide, but epimorphin increased the number of migrated cells 3.18-fold ( P < 0.0001). These results support a novel function of epimorphin in protecting IEC from oxidative stress. This anti-oxidative function of epimorphin is dramatic and is likely mediated by the activation of EGF receptors and the MEK/extracellular signal-regulated kinase and PI3 kinase/Akt signaling pathways and through the induction of anti-apoptotic factors.

Further investigation of the mechanism of Vitreoscilla hemoglobin (VHb) protection from oxidative stress in Escherichia coli

Biologia ◽  
2011 ◽  
Vol 66 (5) ◽  
Author(s):  
Meltem Akbas ◽  
Tugrul Doruk ◽  
Serhat Ozdemir ◽  
Benjamin Stark
Keyword(s):  
Oxidative Stress ◽  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Superoxide Dismutase ◽  
Stationary Phase ◽  
Exponential Phase ◽  
Vitreoscilla Hemoglobin ◽  
Sod Activity ◽  
E Coli ◽  
Hydrogen Peroxide Treatment

AbstractIn Escherichia coli, Vitreoscilla hemoglobin (VHb) protects against oxidative stress, perhaps, in part, by oxidizing OxyR. Here this protection, specifically VHb-associated effects on superoxide dismutase (SOD) and catalase levels, was examined. Exponential or stationary phase cultures of SOD+ or SOD− E. coli strains with or without VHb and oxyR antisense were treated with 2 mM hydrogen peroxide without sublethal peroxide induction, and compared to untreated control cultures. The hydrogen peroxide treatment was toxic to both SOD+ and SOD− cells, but much more to SOD− cells; expression of VHb in SOD+ strains enhanced this toxicity. In contrast, the presence of VHb was generally associated in the SOD+ background with a modest increase in SOD activity that was not greatly affected by oxyR antisense or peroxide treatment. In both SOD+ and SOD− backgrounds, VHb was associated with higher catalase activity both in the presence and absence of peroxide. Contrary to its stimulatory effects in stationary phase, in exponential phase oxyR antisense generally decreased VHb levels.

scholarly journals Oxytocin Promotes C6 Glial Cell Death and Aggravates Hydrogen Peroxide-induced Oxidative Stress

2020 ◽  
pp. 27-33
Author(s):  
Ahmet Sevki Taskiran ◽  
Merve Ergul
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Cell Death ◽  
Cell Viability ◽  
Glial Cell ◽  
Glial Cells ◽  
Control Group ◽  
C6 Cells ◽  
Cox 2 ◽  
Cox 1

Background. Recent studies have shown that oxytocin plays a vital role in neurons and glial cells. However, its effect on hydrogen peroxide (H2O2)-induced oxidative stress as well as cyclooxygenase-1 (COX-1) and COX-2 in glial cells are still unclear. Objective. This study aims to examine the effect of oxytocin on glial cell viability, oxidative stress, COX-1, and COX-2 in C6 glial cells after exposure to H2O2. Methods. In this study, C6 glioma cell line was used to study the effect of oxytocin on the glial cell in four cell groups. The control group was untreated. Cells in the H2O2 group were treated with 0.5 mM H2O2 for 24 h. Cells in the oxytocin group were treated with various concentrations (0.25, 0.5, 1, and 2 μg/mL) of oxytocin for 24 h. Cells in the oxytocin+H2O2 group were pre-treated with various concentrations (0.25, 0.5, 1, and 2 μg/mL) of oxytocin for 1 h before 24-h exposure to 0.5 mM H2O2. Cell viability was evaluated using XTT assay. Total antioxidant status and total oxidant status (TOS), COX-1, and COX-2 levels in the cells were measured by commercial kits. Results. Oxytocin with various concentrations significantly decreased the viability of C6 cells after H2O2-induced oxidative stress (P < 0.01). It also significantly increased the levels of TOS, COX-1, and COX-2 in C6 cells after H2O2-induced oxidative stress (P < 0.001). Conclusion. Oxytocin increases glial cell death after H2O2-induced oxidative damage in C6 cells, along with upregulation of COX-1 and COX-2 levels.

scholarly journals Helicobacter pylori Infection Induces Oxidative Stress and Programmed Cell Death in Human Gastric Epithelial Cells

2007 ◽  
Vol 75 (8) ◽  
pp. 4030-4039 ◽  
Author(s):  
Song-Ze Ding ◽  
Yutaka Minohara ◽  
Xue Jun Fan ◽  
Jide Wang ◽  
Victor E. Reyes ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Cell Death ◽  
Helicobacter Pylori ◽  
Epithelial Cells ◽  
Dna Fragmentation ◽  
Inflammatory Cytokines ◽  
Ros Generation ◽  
Gastric Epithelial Cells ◽  
H Pylori

ABSTRACT Helicobacter pylori infection is associated with altered gastric epithelial cell turnover. To evaluate the role of oxidative stress in cell death, gastric epithelial cells were exposed to various strains of H. pylori, inflammatory cytokines, and hydrogen peroxide in the absence or presence of antioxidant agents. Increased intracellular reactive oxygen species (ROS) were detected using a redox-sensitive fluorescent dye, a cytochrome c reduction assay, and measurements of glutathione. Apoptosis was evaluated by detecting DNA fragmentation and caspase activation. Infection with H. pylori or exposure of epithelial cells to hydrogen peroxide resulted in apoptosis and a dose-dependent increase in ROS generation that was enhanced by pretreatment with inflammatory cytokines. Basal levels of ROS were greater in epithelial cells isolated from gastric mucosal biopsy specimens from H. pylori-infected subjects than in cells from uninfected individuals. H. pylori strains bearing the cag pathogenicity island (PAI) induced higher levels of intracellular oxygen metabolites than isogenic cag PAI-deficient mutants. H. pylori infection and hydrogen peroxide exposure resulted in similar patterns of caspase 3 and 8 activation. Antioxidants inhibited both ROS generation and DNA fragmentation by H. pylori. These results indicate that bacterial factors and the host inflammatory response confer oxidative stress to the gastric epithelium during H. pylori infection that may lead to apoptosis.

scholarly journals Flutamide Induces Hepatic Cell Death and Mitochondrial Dysfunction via Inhibition of Nrf2-Mediated Heme Oxygenase-1

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Li Zhang ◽  
Jiabin Guo ◽  
Qiang Zhang ◽  
Wei Zhou ◽  
Jin Li ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Cell Death ◽  
Liver Injury ◽  
Mitochondrial Dysfunction ◽  
Heme Oxygenase ◽  
Hepatic Cell ◽  
Atp Depletion ◽  
Heme Oxygenase 1 ◽  
Hydrogen Peroxide Accumulation

Flutamide is a widely used nonsteroidal antiandrogen for prostate cancer therapy, but its clinical application is restricted by the concurrent liver injury. Increasing evidence suggests that flutamide-induced liver injury is associated with oxidative stress, though the precise mechanism is poorly understood. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a master transcription factor regulating endogenous antioxidants including heme oxygenase-1 (HO-1). This study was designed to delineate the role of Nrf2/HO-1 in flutamide-induced hepatic cell injury. Our results showed that flutamide concentration dependently induced cytotoxicity, hydrogen peroxide accumulation, and mitochondrial dysfunction as indicated by mitochondrial membrane potential loss and ATP depletion. The protein expression of Nrf2 and HO-1 was induced by flutamide at 12.5 μM but was downregulated by higher concentrations of flutamide. Silencing either Nrf2 or HO-1 was found to aggravate flutamide-induced hydrogen peroxide accumulation and mitochondrial dysfunction as well as inhibition of the Nrf2 pathway. Moreover, preinduction of HO-1 by Copp significantly attenuated flutamide-induced oxidative stress and mitochondrial dysfunction, while inhibition of HO-1 by Snpp aggravated these deleterious effects. These findings suggest that flutamide-induced hepatic cell death and mitochondrial dysfunction is assoicated with inhibition of Nrf2-mediated HO-1. Pharmacologic intervention of Nrf2/HO-1 may provide a promising therapeutic approach in flutamide-induced liver injury.

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