title: Protective effects of olive oil phenolics and gallic acid on hydrogen peroxide-induced apoptosis.
abstract: OBJECTIVE
  Olive oil contains several phenolic compounds possessing antioxidant activity. The aim of this study was to investigate the protective effects of olive oil phenolic extract (OOPE) and one of its constituents, gallic acid (GA) against H(2)O(2)-induced oxidative stress and apoptotic cell death in HeLa cells, a model for human epithelial cells.
  
  
  METHODS
  The cells were pretreated with nontoxic doses of OOPE or GA for 4, 24 and 48 h, and the intracellular reactive oxygen species (ROS) level was determined, before and after oxidative stress induction with H(2)O(2). As an indicator of apoptosis, caspase 9 activity was measured.
  
  
  RESULTS
  All pretreatments reduced ROS generation. Four hour incubation with OOPE or GA completely inhibited ROS generation. Increases in caspase 9 activity by OOPE and GA pretreatment under harsh stress conditions were inhibited 92 and 67.8%, respectively.
  
  
  CONCLUSIONS
  These results suggest that OOPE and GA act as powerful antioxidants against oxidative stress and exert anti-apoptotic effects.
authors.affiliation: Department of Biology, Faculty of Arts and Sciences, Çanakkale Onsekiz Mart University, Terzioglu Campus, 17020 Çanakkale, Turkey. ozlemerolbio@gmail.com
authors.forename: Özlem
authors.initials: Ö
authors.lastname: Erol-Dayi
authors.forename: Nazlı
authors.initials: N
authors.lastname: Arda
authors.forename: Günhan
authors.initials: G
authors.lastname: Erdem
mesh_terms: D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D053453:Caspase 9 / Q000235:genetics / Q000378:metabolism; D004249:DNA Damage; D005707:Gallic Acid / Q000494:pharmacology*; D006367:HeLa Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity*; D000069463:Olive Oil; D018384:Oxidative Stress / Q000187:drug effects; D010636:Phenols / Q000494:pharmacology*; D010938:Plant Oils / Q000737:chemistry*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000975:Antioxidants; D000069463:Olive Oil; D010636:Phenols; D010938:Plant Oils; D017382:Reactive Oxygen Species; D005707:Gallic Acid; D006861:Hydrogen Peroxide; C506433:CASP9 protein, human; D053453:Caspase 9
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