Olive oil phenolics: effects on DNA oxidation and redox enzyme mRNA in prostate cells.
Hydroxytyrosol, tyrosol and caffeic acid effects on hydrogen peroxide-induced DNA damage, hydroperoxide generation and redox enzyme gene expression were studied in oxidative-stress-sensitive human prostate cells (PC3). Hydroxytyrosol led to lower levels of hydroperoxides, DNA damage, and mRNA levels of classic glutathione peroxidase (GPx) for all the studied concentrations. Only hydroxytyrosol was effective at low concentrations (10 microm). Tyrosol reduced DNA oxidation only at high (>50 microm) concentrations and increased hydroperoxides, GPx and phospholipid hydroperoxide GPx mRNA levels. Caffeic acid elicited effects between those of the other two phenolics. Results indicate that hydroxytyrosol is the only significant antioxidant phenolic in olive oil and may be the major component accounting for its beneficial properties. Tyrosol appeared to exhibit pro-oxidant effects (only at high concentrations) and caffeic acid was neutral. Both number and position of hydroxyl groups appear to play a role in the cellular effects of hydroxytyrosol.
Institute of Nutrition and Food Technology, Department of Physiology, University of Granada, Granada, Spain. jlquiles@ugr.es
José L
JL
Quiles
Andrew J
AJ
Farquharson
David K
DK
Simpson
Ian
I
Grant
Klaus W J
KW
Wahle
D000975:Antioxidants / Q000494:pharmacology; D002109:Caffeic Acids / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D004249:DNA Damage; D004042:Dietary Fats, Unsaturated / Q000494:pharmacology*; D005979:Glutathione Peroxidase / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D000069463:Olive Oil; D010084:Oxidation-Reduction / Q000187:drug effects; D010636:Phenols / Q000494:pharmacology*; D010626:Phenylethyl Alcohol / Q000031:analogs & derivatives* / Q000494:pharmacology; D010938:Plant Oils / Q000494:pharmacology*; D011467:Prostate / Q000187:drug effects* / Q000201:enzymology; D012333:RNA, Messenger / Q000235:genetics; D014407:Tumor Cells, Cultured
D000975:Antioxidants; D002109:Caffeic Acids; D004042:Dietary Fats, Unsaturated; D000069463:Olive Oil; D010636:Phenols; D010938:Plant Oils; D012333:RNA, Messenger; C005975:3,4-dihydroxyphenylethanol; C011867:4-hydroxyphenylethanol; D005979:Glutathione Peroxidase; D010626:Phenylethyl Alcohol; C040048:caffeic acid