The dietary antioxidants resveratrol and quercetin protect cells from exogenous pro-oxidative damage Ulrike Kaindla, Isgard Eyberga, Natalia Rohr-Udilovaa, Christine Heinzlea and Brigitte Marian, a, aDepartment of Medicine 1, Institute of Cancer Research, Medical University Vienna, Borschkegasse 8a, 1090 Vienna, Austria Abstract In the colorectal epithelium oxidative stress is observed endogenously in premalignant adenoma cells or induced by nutritional factors like fatty acid hydroperoxides (LOOH). Bioactive phenols like resveratrol and quercetin can quench reactive oxygen species and protect from pro-oxidative damage. Our study used colorectal adenoma and carcinoma cell lines to assess antioxidant protective effects of resveratrol and quercetin. It demonstrated that both compounds efficiently protect from oxidative stress induced by LOOH. Effective concentrations (10 microMoler resveratrol and 1 microMoler quercetin) (sorry symbol will not reproduce) can easily be reached in the intestinal lumen after consumption of plant foods or food supplements. Both compounds prevent LOOH-induced formation of intracellular H2O2, stimulation of cyclooxygenase-2 and vascular endothelial growth factor. For reduction of endogenous H2O2 levels in colorectal tumor cells higher antioxidant-concentrations are needed in all cell lines. Quercetin (10 microMoler) alone even increased H2O2 in LT97 adenoma cells and stimulated VEGF production. Resveratrol and quercetin also induced 10–30% and 40–60% cell loss respectively by apoptosis. In summary, this indicates that resveratrol and quercetin have little protective capacity in absence of exogenous stress. They are however highly efficient in protecting against nutrition induced oxidative stress damage suggesting that this constitutes the major part of their tumor protective activity. Food and Chemical Toxicology Volume 46, Issue 4, April 2008, Pages 1320-1326 Molecular and Physiological Effects of Bioactive Food Components Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.