title: Extra virgin olive oil phenolic extracts counteract the pro-oxidant effect of dietary oxidized lipids in human intestinal cells.
abstract: The phenolic fraction of extra virgin olive oil (EVOO) concentrates before absorption in the intestinal lumen, where it may contribute to the modulation of enterocytes response to oxidative and inflammatory stimuli. We evaluated the ability of two monovarietal EVOOs phenolic extracts, Bosana and Nera di Gonnos/Tonda di Cagliari, typical and widespread varieties in Sardinia (Italy), to counteract in enterocytes like Caco-2 cells the pro-oxidant action of oxidized lipids, tert-butyl hydroperoxide (TBH) or a mixture of oxysterols of dietary origin. We confirmed that TBH treatment causes a significant increase of ROS production, GSH depletion, increase of MDA, fatty acids hydroperoxides and 7-ketocholesterol, and showed first evidence of oxidative imbalance and cell damage due to oxysterols exposure. Preincubation of cells with the phenolic extracts significantly attenuated oxidative modifications. Bosana extract showed the highest concentration of total phenols, mainly hydroxytyrosol and tyrosol, and was the most active in presence of TBH, where the free radical scavenging activity of these simple phenols seems to be a determining factor. The two extracts were equally effective, in spite of the different composition, in presence of oxysterols, where ROS production probably occurs according to different and more complex mechanisms.
authors.affiliation: Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Incani
authors.affiliation: Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy.
authors.forename: Gessica
authors.initials: G
authors.lastname: Serra
authors.affiliation: Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Atzeri
authors.affiliation: Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy.
authors.forename: Maria Paola
authors.initials: MP
authors.lastname: Melis
authors.affiliation: Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Serreli
authors.affiliation: AGRIS Sardinia, Agricultural Research Agency of Sardinia, Sassari, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Bandino
authors.affiliation: AGRIS Sardinia, Agricultural Research Agency of Sardinia, Sassari, Italy.
authors.forename: Piergiorgio
authors.initials: P
authors.lastname: Sedda
authors.affiliation: AGRIS Sardinia, Agricultural Research Agency of Sardinia, Sassari, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Campus
authors.affiliation: Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy. Electronic address: tuberoso@unica.it.
authors.forename: Carlo I G
authors.initials: CI
authors.lastname: Tuberoso
authors.affiliation: Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy. Electronic address: mdeiana@unica.it.
authors.forename: Monica
authors.initials: M
authors.lastname: Deiana
mesh_terms: D018938:Caco-2 Cells; D004041:Dietary Fats; D006801:Humans; D008055:Lipids / Q000009:adverse effects* / Q000737:chemistry; D000069463:Olive Oil / Q000737:chemistry*; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D004041:Dietary Fats; D008055:Lipids; D000069463:Olive Oil; D010636:Phenols; D010936:Plant Extracts
keywords: Caco-2 cells; Olive oil; Oxidative stress; Oxysterols; Phenolic extract