The protein kinase C inhibitor, staurosporine, inhibited NADPH oxidase activity of human neutrophils activated by phorbol myristate acetate. However, this inhibitor had no effect on either the initiation or the maximal rate of O2- secretion activated by the chemotactic peptide, fMet-Leu-Phe, but resulted in a more rapid termination of oxidant production. Similarly, staurosporine had no effect o...

The objective of this study was to investigate membrane fatty acids for their effects on mitochondrial function in live cells. Mitochondrial potential and oxidant production were measured in human colonic adenocarcinoma (HT-29) cells with membranes enhanced in either oleic acid, linoleic acid, arachidonic acid, eicosapentaenoic acid, or docosahexaenoic acid. Docosahexaenoic acid-enriched cells ...

We tested the hypothesis that oxidant-injured cells upregulate thioredoxin, whereas oxidant-stressed, but not injured, cells upregulate interleukin (IL)-8 after injury. We exposed primary human tracheobronchial epithelial cells and transformed human bronchial epithelial cells (BEAS-2B S.6) to 0, 200, 400, or 600 microM H(2)O(2) for 1 h followed by an additional 7 h of incubation. Subsequently, ...

Inflammatory bowel disease (IBD) affects more than 1 million Americans with more than 30,000 new cases diagnosed each year. IBD increases patient morbidity and susceptibility to colorectal cancer, yet its etiology remains unknown. Current models identify two key determinants of IBD pathogenesis: hyperpermeability of the gut epithelial barrier to bacterial products and an abnormal immune respons...

The pathogenesis of asthma and chronic obstructive pulmonary disease (COPD) has been claimed to be attributable to increased systemic and local oxidative stress. Detection of the oxidant burden and evaluation of their progression and phenotypes by oxidant biomarkers have proved challenging and difficult. A large number of asthmatics are cigarette smokers and smoke itself contains oxidants compl...

Although oxidant generation by NADPH oxidase is known to play an important role in signaling in endothelial cells, the basis of activation of NADPH oxidase is incompletely understood. The atypical isoform of protein kinase C, PKC , has been implicated in the mechanism of tumor necrosis factor(TNF)–induced oxidant generation in endothelial cells; thus, in the present study, we have addressed the...

Xanthine oxidase is a key enzyme responsible for hyperuricemia, a pre-disposing factor for Gout and oxidative stress-related diseases. Only two clinically approved xanthine oxidase inhibitors Allopurinol and Febuxostat are currently used for treatment of hyperuricemia. However, owing to their side effects there is a need for new non-purine-based selective inhibitors of xanthine oxidase. In the ...

Epithelial mucous membranes are repeatedly exposed to oxidants and xenobiotics. CFTR plays a role in glutathione transepithelial flux and in defining the hydration and viscoelasticity of protective mucus. We therefore hypothesized that CFTR expression and function may be modulated by oxidant stress. A sublethal oxidant stress (tert-butylhydroquinone, BHQ) in CFTR-expressing epithelial cells (T8...

To explore how screening for potential nutrient bio-activity could be improved by integrating biological and chemical markers of cellular responses, we assessed the effect of the known anti-oxidants, catechin and chlorogenic acid, on anti-oxidant activity in vitro. We determined an active concentration (25 μM) of each compound and then measured its effects on anti-oxidant gene expression and re...

Airborne fine particle mass concentrations (PM2.5) are used for ambient air quality management worldwide based in part on known cardiorespiratory health effects. While oxidative stress is generally thought to be an important mechanism in determining these effects, relatively few studies have specifically examined how oxidant defence may impact susceptibility to particulate air pollution. Here w...