Nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) is the primary transcription factor protecting cells from oxidative stress by regulating cytoprotective genes, including the antioxidant glutathione (GSH) pathway. GSH maintains cellular redox status and affects redox signaling, cell proliferation, and death. GSH homeostasis is regulated by de novo synthesis as well ...

Oxidative processes in the lenses are the most commonly found damaging factor for the development of cataracts. Hirudin, a most potent inhibitor of thrombin as an antithrombic drug, also have potential use in cataracts. In order to investigate the mechanisms of hirudin against galactose-induced cataract at the cellular level. We ...

Oxidative stress plays a key role in the pathogenesis of aging and many metabolic diseases; therefore, an effective antioxidant therapy would be of great importance in these circumstances. Nutritional, environmental, and chemical factors can induce the overproduction of the superoxide anion radical in both the cytosol and mitochondria. This is ...

Thalidomide as an effective treatment for multiple myeloma and leprosy has also caused birth defects in thousands of children five decades ago particularly in Europe. Thus its use in humans remains limited. The rapid and fatal approval of thalidomide at that time ultimately was a consequence of the sole use ...

Aldose reductase (AR) is abundantly expressed in a variety of cell lineages and has been implicated in the cellular response against oxidative stress. However, the exact functional role of AR against oxidative stress remains relatively unclear. This study investigated the role of AR in acrolein- or hydrogen peroxide-induced apoptosis using ...

Isocyanates, a group of low molecular weight aromatic and aliphatic compounds containing the isocyanate group (-NCO), are important raw materials with diverse industrial applications; however, pathophysiological implications resulting from occupational and accidental exposures of these compounds are hitherto unknown. Although preliminary evidence available in the literature suggests that isocyanates and ...

Thalidomide as an effective treatment for multiple myeloma and leprosy has also caused birth defects in thousands of children five decades ago particularly in Europe. Thus its use in humans remains limited. The rapid and fatal approval of thalidomide at that time ultimately was a consequence of the sole use ...

Intracellular glutathione (GSH) depletion is an important hallmark of apoptosis. We have recently shown that GSH depletion by its extrusion regulates apoptosis independently of excessive reactive oxygen species accumulation. However, the mechanisms by which GSH depletion regulates apoptosis are still unclear. Because disruption of intracellular ionic homeostasis, associated with apoptotic ...

One of the most notorious environmental toxicants, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), easily accumulates in the environment and most organisms, including humans, because of its high lipophilicity and resistance to degradation. TCDD exposure causes a variety of adverse health effects in humans including immunotoxicity, hepatotoxicity, neurotoxicity, and carcinogenesis. For the most part, studies ...

Three novel lipid-shell-type microbubbles (MBs), AS-0100, BG6356A and BG6356B, have been evaluated for their impact on ultrasound (US)-induced cell death and free radicals production. Previously studied and well-characterized US exposure conditions were employed in which human myelomonocytic lymphoma U937 cells were exposed to 1MHz pulsed US beam (0.3W/cm(2), 10% duty ...

RLIP76, a stress-responsive, multi-functional protein with multi-specific transport activity towards glutathione-conjugates (GS-E) and chemotherapeutic agents, is frequently over-expressed in malignant cells. Our recent studies suggest that it plays a prominent anti-apoptotic role selectively in cancer cells. We have previously shown that RLIP76 accounts for up to 80% of the transport ...

Oxidative stress plays an important role in the pathological processes of various neurodegenerative diseases. Ugonin K, a flavonoid isolated from the rhizomes of Helminthostachys zeylanica, possesses potent antioxidant property. In this study, we investigate the neuroprotective effects of ugonin K on hydrogen peroxide (H(2)O(2))-induced apoptosis in SH-SY5Y cells. Incubation of ...

This study was designed to analyze the chemical composition of Citrus obovoides (Geumgamja) and Citrus natsudaidai (Cheonyahagyul) oils and to test their biological activities. These citrus essential oils were obtained by steam distillation of fruits collected from Jeju Island, Korea, and were analyzed using gas chromatograph (GC)-flame ionization detectors (FID) ...

Chronically-elevated blood glucose initiates a harmful series of processes in which toxic reactive species play crucial roles. Oxidative as well as nitro-oxidative stress is harmful for virtually all biomolecules including lipids, proteins and DNA. Such pathophysiologic mechanisms eventually results in cellular dysfunction, apoptosis or necrosis. Melatonin is a multifunctional indolamine ...

This study was conducted to investigate the effects of mechanical stress, particularly cyclic strain, on proinflammatory cytokines as well as antioxidant properties and their interactions with cellular defense systems in human dental pulp (HDP) cells. Exposure of HDP cells to mechanical strain induced inflammatory cytokines such as interleukin-1 beta, tumor ...

The aim of the present work was to study some of the adverse effects produced by hyperandrogenism on the uterine function. Daily injection of dehydroepiandrosterone (DHEA: 6 mg/ 100 g body weight, sc) for 20 consecutive days induced polycystic ovaries in BALB/c mice. In this model, we found that DHEA ...

There is a current interest in dietary compounds (such as trans-resveratrol) that can inhibit or reverse oxidative stress, the common pathway for a variety of brain disorders, including Alzheimer's disease and stroke. The objective of the present study was to investigate the effects of resveratrol, under conditions of oxidative stress ...

The present study was conducted to investigate the role of arjunolic acid (AA) against sodium fluoride (NaF)-induced cytotoxicity and necrotic cell death in murine hepatocytes. Dose-dependent studies suggest that incubation of hepatocytes with NaF (100mM) for 1h significantly decreased the cell viability as well as intracellular antioxidant power. Besides, NaF ...

Staurosporine (STP) was shown to induce cell apoptosis through formation of reactive oxygen species, but a role for cellular redox has not been defined. In this study, we report that STP (2 microM) caused apoptosis (24+/-3% at 24 h) of human colon adenocarcinoma epithelial cell line HT29 that was preceded ...

Oxidative stress is one of the hypotheses involved in the etiology of Alzheimer's disease (AD). Considerable attention has been focused on increasing the intracellular glutathione (GSH) levels in many neurodegenerative diseases, including AD. Pycnogenol (PYC) has antioxidant properties and stabilizes intracellular antioxidant defense systems including glutathione levels. The present study ...

Present study investigated whether endosulfan, an organochlorine pesticide is able to deplete glutathione (GSH) and induce apoptosis in human peripheral blood mononuclear cells (PBMC) in vitro. The role of oxidative stress in the induction of apoptosis was also evaluated by the measurement of the GSH level in cell lysate. The ...

Selenium is an essential micronutrient for man and animals. The role of selenium has been attributed largely to its presence in selenoproteins as the 21st amino acid, selenocysteine (Sec, U). Sec is encoded by TGA in DNA. A unique mechanism is used to decode the UGA codon in mRNA to ...

Glutathione (GSH) is a major antioxidant as well as redox and cell signaling regulator. GSH guards cells against oxidative injury by reducing H(2)O(2) and scavenging reactive oxygen and nitrogen radicals. In addition, GSH-induced redox shift with or without ROS subjects some cellular proteins to varied forms of oxidation, altering the ...

Ethanol-induced hepatocyte necrosis and apoptosis are valid in vitro models to investigate the modulatory effects of hepatoprotective/toxic agents such as curcumin. In this study, suspension and monolayer cultures of isolated rat hepatocytes were used. Levels of trypan blue uptake, reduced glutathione, and lipid peroxidation were quantified. Chromatin condensation, caspase-3 activity, ...

Methylmercury (MeHg) is an environmental toxin that causes severe neurological complications in humans and experimental animals. In addition to neurons, glia in the central nervous system are very susceptible to MeHg toxicity. Pretreatment of glia with the prostaglandin derivative, 15-deoxy-delta-12,14-prostaglandin J(2) (15d-PGJ(2)), caused a significant protection against MeHg cytotoxicity. Results ...

We elucidated the cytoprotective effects of hyperoside (quercetin-3-O-galactoside) against hydrogen peroxide (H2O2)-induced cell damage. We found that hyperoside scavenged the intracellular reactive oxygen species (ROS) detected by fluorescence spectrometry, flow cytometry, and confocal microscopy. In addition, we found that hyperoside scavenged the hydroxyl radicals generated by the Fenton reaction (FeSO4)+H2O2) ...

The chemoprotective effect of hydroxytyrosol (HT), a strong antioxidant compound from extra virgin olive oil, against acrylamide (AA)-induced genotoxicity was investigated in a human hepatoma cell line, HepG2. The micronucleus test (MNT) assay was used to monitor genotoxicity. In MNT, we found that HT at all tested concentrations (12.5-50 microM) ...

Phytochemicals (PhC) are a ubiquitous class of plant secondary metabolites. A "recommended" human diet should warrant a high proportion of energy from fruits and vegetables, therefore providing, among other factors, a huge intake of PhC, in general considered "health promoting" by virtue of their antioxidant activity and positive modulation, either ...

Reactive oxygen species act as signaling molecules but can also directly provoke cellular damage by rapidly oxidizing cellular components, including lipids. We developed a high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry-based quantitative method that allowed us to discriminate between free radical (type I)- and singlet oxygen ((1)O(2); type II)-mediated lipid peroxidation ...

Apoptosis or programmed cell death represents a physiologically conserved mechanism of cell death that is pivotal in normal development and tissue homeostasis in all organisms. As a key modulator of cell functions, the most abundant non-protein thiol, glutathione (GSH), has important roles in cellular defense against oxidant aggression, redox regulation ...

Telomere shortening and redox imbalance have been related to the aging process. We used cultured mouse embryonic fibroblasts (MEF) isolated from mice lacking telomerase activity (Terc(-/-)) to analyze the redox balance and the functional consequences promoted by telomerase deficiency. Comparison with wild-type (WT) MEF showed that Terc(-/-) MEF had greater ...

Chronic cigarette smoking evokes a lung glutathione (GSH) adaptive response that results in elevated GSH levels in the lung epithelial lining fluid (ELF). Currently, little is known about how the lung regulates or maintains steady-state levels of ELF GSH. Pathogens such as Mycoplasma pneumoniae can exacerbate airway inflammation and oxidative ...

Reactive oxygen species can be important mediators of damage to cell molecules and structures. Besides the endogen antioxidant defences, the antioxidant intake in the diet has an important role in the protection against the development of diseases produced by oxidative damage. Resveratrol is a naturally occurring compound present in many ...

Arsenic trioxide (ATO) affects many biological processes such as cell proliferation, apoptosis, differentiation and angiogenesis. L-buthionine sulfoximine (BSO) is an inhibitor of GSH synthesis. We tested whether ATO reduced the viability of lung cancer A549 cells in vitro, and investigated the in vitro effect of the combination of ATO and ...

The incidence of post-transplant lymphoproliferative disorder (PTLD) has increased since cyclosporin A (CsA) became the mainstay of transplant immunosuppression. We have previously shown that, in addition to its potent immunosuppressive property, CsA-induced oxidative stress plays an important role in Epstein-Barr virus (EBV)-related PTLD. Using lipid hydroperoxide and malondialdehyde as markers ...

Carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP) is an uncoupler of mitochondrial oxidative phosphorylation in eukaryotic cells. Here, we investigated an involvement of O(2)(*-) and GSH in FCCP-induced Calu-6 cell death and examined whether ROS scavengers rescue cells from FCCP-induced cell death. Levels of intracellular O(2)(*-) were markedly increased depending on the ...

Peroxisomes generate hydrogen peroxide, a reactive oxygen species, as part of their normal metabolism. A number of pathological situations exist in which the organelle's capacity to degrade the potentially toxic oxidant is compromised. It is the peroxidase, catalase, which largely determines the functional antioxidant capacity of the organelle, and it ...

The proteins responsible for reduced glutathione (GSH) export under both basal conditions and in cells undergoing apoptosis have not yet been identified, although recent studies implicate some members of the multidrug resistance-associated protein family (MRP/ABCC) in this process. To examine the role of MRP1 in GSH release, the present study ...

Cadmium (Cd), a well known environmental carcinogen, is a potent immunotoxicant. In rodents, it is primarily characterized by marked thymic atrophy and splenomegaly. Cadmium induces apoptosis in murine lymphocytes and alters the immune functions. Thus, for the amelioration of its effect, three structurally different bioactive herbal extracts such as piperine-alkaloid, ...

The in vitro antibacterial, antioxidant, cytotoxic and apoptotic activities from tubers extracts of Cyperus rotundus (Cyperaceae) were investigated. Antibacterial activity of different extracts was evaluated against five bacterial reference strains. A marked inhibitory effect was observed against Salmonella enteritidis, Staphylococcus aureus and Enterococcus faecalis with total oligomers flavonoids (TOFs) and ...

Levels of inflammatory cytokines are raised in chronic obstructive pulmonary disease (COPD). A diet rich in antioxidant vitamins may protect against the development of COPD. This study examined the effects of phenolic compounds and food sources on cytokine and antioxidant production by A549 cells. The effects of the following phenolic ...

Free radicals induce oxidative stress in vivo, leading to various disorders and diseases. In the present study, the effect of oxygen pressure on the cytotoxicity induced by free radicals was studied. It was found that alkyl radicals markedly aggravated Jurkat cell apoptosis under low oxygen pressure and this was ascribed ...

Arsenic trioxide (ATO) can regulate many biological functions such as apoptosis and differentiation in various cells. We investigated an involvement of ROS such as H(2)O(2) and O(2)(*-), and GSH in ATO-treated Calu-6 cell death. The levels of intracellular H(2)O(2) were decreased in ATO-treated Calu-6 cells at 72 h. However, the ...

OBJECTIVE: Free radical damage, inflammation, and apoptosis play a critical role in the onset and progression of cartilage erosion in arthritis. Many studies have demonstrated that glycosaminoglycans (GAGs), and chondroitin-4-sulphate (C4S) in particular, possess antioxidant activity that is able to inhibit lipid peroxidation which is the main mechanism of free ...

ABSTRACT Levels of dietary selenium are inversely associated with cancer risk in humans, and selenium has played a major role in the field of chemoprevention. In particular, the organoselenium agents 1,4-phenylenebis(methylene)seleno-cyanate (p-XSC) and its glutathione conjugate, p-XSeSG, are effective in preventing cancers at numerous sites, including the lung in rodent ...

Selenium is an essential dietary element with antioxidant roles in immune regulation, but there is little understanding of how this element acts at the molecular level in host defense and inflammatory disease. Selenium is incorporated into the amino acid selenocysteine (Sec), which in turn is inserted into selenoproteins in a ...

Here we report for the first time that L-amino acid oxidase (LAAO), a major component of snake venom, induces apoptosis in yeast. The causative agent for induction of apoptosis has been shown to be hydrogen peroxide, produced by the enzymatic activity of LAAO. However, the addition of catalase, a specific ...

Ionizing radiation is known to cause tissue damage in biological systems, mainly due to its ability to produce reactive oxygen species (ROS) in cells. Many thiol antioxidants have been used previously as radioprotectors, but their application has been limited by their toxicity. In this investigation, we have explored the possible ...

Leukotrienes (LTs) are one of the most important mediators in the pathophysiology of asthma. We measured the intracellular amounts of reduced glutathione (GSH) and oxidized glutathione (GSSG) in cultured human airway epithelial cells. LTC 4 affects the GSH/GSSG ratio by activating signals to increase interleukin-8 (IL-8) production. Pretreatment with a ...

PURPOSE: To investigate the possible protective effect of the dietary antioxidant quercetin on retinal pigment epithelial (RPE) cell dysfunction and cellular senescence occurring in age-related macular degeneration (AMD). The major flavonoid quercetin was studied on RPE cells in vitro. METHODS: Cultured human RPE cells were incubated with different concentrations of ...