Effects of red grape juice polyphenols in NADPH oxidase subunit expression in human neutrophils and mononuclear blood cells

Abstract

The NADPH oxidase enzyme system is the main source of superoxide anions in phagocytic and vascular cells. NADPH oxidase-dependent superoxide generation has been found to be abnormally enhanced in several chronic diseases. Evidence is accumulating that polyphenols may have the potential to improve cardiovascular health, although the mechanism is not fully established. Consumption of concentrated red grape juice, rich in polyphenols, has been recently shown to reduce NADPH oxidase activity in circulating neutrophils from human subjects. In the present work we studied whether red grape juice polyphenols affected NADPH oxidase subunit expression at the transcription level. For this, we used human neutrophils and mononuclear cells from peripheral blood, HL-60-derived neutrophils and the endothelial cell line EA.hy926.Superoxide production was measured with 2 0 7 0 -dichlorofluorescein diacetate or lucigenin, mRNA expression by real-time RT-PCR and protein expression by Western blot. Each experiment was performed at least three times. In all cell types tested, red grape juice, dealcoholised red wine and pure polyphenols decreased superoxide anion production. Red grape juice and dealcoholised red wine selectively reduced p47phox, p22phox and gp91phox expression at both mRNA and protein levels, without affecting the expression of p67phox. Pure polyphenols, particularly quercetin, also reduced NADPH oxidase subunit expression, especially p47phox, in all cell types tested. The present results showing that red grape juice polyphenols reduce superoxide anion production provide an alternative mechanism by which consumption of grape derivatives may account for a reduction of oxidative stress associated with cardiovascular and/or inflammatory diseases related to NADPH oxidase superoxide overproduction.

Midazolam Induces Cellular Apoptosis in Human Cancer Cells and Inhibits Tumor Growth in Xenograft Mice

“…The NF-κB pathway augments pro-survival signaling by activating PI3K/AKT/ERK1/2 pathways and ultimately leads to the phosphorylation inactivation of proapoptotic proteins such as Bid and Bax and upregulation of anti-apoptotic genes such as Bcl-2 and Bcl-X L (McCubrey et al, 2007). The Nox-dependent superoxide generation has been found to be abnormally enhanced in several chronic diseases including cancer (Davalos et al, 2009). We found that midazolam inhibits the enzyme activity of Nox2 subunits in K562 cells (Fig.…”

Procyanidins from grape pomace are suitable inhibitors of human endothelial NADPH oxidase

“…Furthermore, polyphenols from grape extracts, sometimes with a high content of procyanidins, have been demonstrated to reduce NADPH oxidase subunit expression in human neutrophil mononuclear cells and in an endothelial cell line [Davalos et al, 2009]; and at the left ventricle in a model of highfructose-fed rats [Al-Awwadi et al, 2005] and in an obese hamster model [Decorde et al, 2009]. These effects on NADPH oxidase expression could have contributed to the direct NADPH oxidase inhibitory activity observed in our in vivo treatments of grape procyanidins.…”

Regulation of NADPH oxidase (Nox2) by lipid rafts in breast carcinoma cells

“…NADPH oxidase-dependent superoxide generation has been found to be abnormally enhanced in several chronic diseases (40). However, extensive analysis of the expression of NADPH oxidase subunits, particularly two critical subunits gp91 phox and p22 phox , in breast cancer cells and their regulation in lipid rafts has not yet been reported.…”