Single and repeated moderate consumption of native or dealcoholized red wine show different effects on antioxidant parameters in blood and DNA strand breaks in peripheral leukocytes in healthy volunteers: a randomized controlled trial [ISRCTN68505294]

BACKGROUND: Red wine (RW) is rich in antioxidant polyphenols that might protect from oxidative stress related diseases, such as cardiovascular disease and cancer. Antioxidant effects after single ingestion of RW or dealcoholized RW (DRW) have been observed in several studies, but results after regular consumption are contradictory. Thus, we examined if single or repeated consumption of moderate amounts of RW or DRW exert antioxidant activity in vivo. METHODS: Total phenolic content and concentration of other antioxidants in plasma/serum, total antioxidant capacity (TEAC) in plasma as well as DNA strand breaks in peripheral leukocytes were measured in healthy non-smokers A) before, 90 and 360 min after ingestion of one glass of RW, DRW or water; B) before and after consumption of one glass of RW or DRW daily for 6 weeks. DNA strand breaks (SB) were determined by single cell gel electrophoresis (Comet Assay) in untreated cells and after induction of oxidative stress ex vivo with H(2)O(2 )(300 μM, 20 min). RESULTS: Both RW and DRW transiently increased total phenolic content in plasma after single consumption, but only RW lead to a sustained increase if consumed regularly. Plasma antioxidant capacity was not affected by single or regular consumption of RW or DRW. Effects of RW and DRW on DNA SB were conflicting. DNA strand breaks in untreated cells increased after a single dose of RW and DRW, whereas H(2)O(2 )induced SB were reduced after DRW. In contrast, regular RW consumption reduced SB in untreated cells but did not affect H(2)O(2 )induced SB. CONCLUSION: The results suggest that consumption of both RW and DRW leads to an accumulation of phenolic compounds in plasma without increasing plasma antioxidant capacity. Red wine and DRW seem to affect the occurrence of DNA strand breaks, but this cannot be referred to antioxidant effects

Reactive Oxygen Species Mediate Oxidized Low-Density Lipoprotein-Induced Inhibition of Oct-4 Expression and Endothelial Differentiation of Bone Marrow Stem Cells

This study was to test the hypothesis that oxidized low-density lipoprotein (ox-LDL) modified the behavior of bone marrow stem cells, including proliferation, Oct-4 expression, and their endothelial differentiation through reactive oxygen species (ROS) formation in vitro. Rat bone marrow multipotent adult progenitor cells (MAPCs) were treated with ox-LDL with or without the antioxidant N-acetylcysteine (NAC). Ox-LDL generated a significant amount of ROS in the culture system as measured with electron paramagnetic resonance spectroscopy, and substantially inhibited the proliferation, Oct-4 expression, and endothelial differentiation of MAPCs. ROS production from ox-LDL in the culture system was completely prevented by NAC (1 mM). NAC treatment completely restored endothelial differentiation potential of MAPCs that was diminished by low-dose ox-LDL. NAC also significantly, but not completely, reversed the inhibitory effect of ox-LDL on proliferation and Oct-4 expression in MAPCs. NAC treatment only slightly restored Akt phosphorylation impaired by ox-LDL in the cells. ROS formation was important in the action of ox-LDL on MAPCs, including Oct-4 expression, proliferation, and endothelial differentiation. However, other mechanism(s) like Akt signaling and apoptosis might also play a critical role in mediating the effect of ox-LDL on these cells. Antioxid. Redox Signal. 13, 1845–1856