title: Protective effect of simple phenols from extravirgin olive oil against lipid peroxidation in intestinal Caco-2 cells.
abstract: Complex polyphenols present in extravirgin olive oil are not directly absorbed, but undergo gastrointestinal biotransformation, increasing the relative amount of tyrosol (TYR) and hydroxytyrosol (HT) entering the small and large intestine. We investigated the capacity of TYR and HT to inhibit the insult of dietary lipid hydroperoxydes on the intestinal mucosa, using cultures of Caco-2, a cell line with enterocyte-like features, and studying the effect of tert-butyl hydroperoxide (TBH) treatment on specific cell membrane lipid targets. The effect of homovanillic alcohol (HVA), metabolite of HT in humans and detected as metabolite of HT in Caco-2 cells, was also evaluated. Exposure to TBH induced a significant increase of the level of MDA, the formation of fatty acid hydroperoxides and 7-ketocholesterol and the loss of α-tocopherol. Pretreatment with both HT and HVA protected Caco-2 cells from oxidative damage: there was no significant detection of oxidation products and the level of α-tocopherol was preserved. Noteworthy, TYR also exerted a protective action against fatty acids degradation. In vitro trials, where the simple phenols were tested during linoleic acid and cholesterol oxidation, gave evidence of a direct scavenging of peroxyl radicals and suggested a hydrogen atom-donating activity.
authors.affiliation: Dipartimento di Biologia Sperimentale, Sezione di Patologia Sperimentale, Università degli Studi di Cagliari, Cittadella Universitaria SS 554, 09042 Monserrato, Cagliari, Italy. mdeiana@unica.it
authors.forename: Monica
authors.initials: M
authors.lastname: Deiana
authors.forename: Giulia
authors.initials: G
authors.lastname: Corona
authors.forename: Alessandra
authors.initials: A
authors.lastname: Incani
authors.forename: Debora
authors.initials: D
authors.lastname: Loru
authors.forename: Antonella
authors.initials: A
authors.lastname: Rosa
authors.forename: Angela
authors.initials: A
authors.lastname: Atzeri
authors.forename: M
authors.initials: M
authors.lastname: Paola Melis
authors.forename: M
authors.initials: M
authors.lastname: Assunta Dessì
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D018938:Caco-2 Cells; D002470:Cell Survival / Q000187:drug effects; D002784:Cholesterol / Q000737:chemistry; D005227:Fatty Acids / Q000737:chemistry; D016166:Free Radical Scavengers / Q000737:chemistry; D006801:Humans; D007653:Ketocholesterols / Q000737:chemistry; D019787:Linoleic Acid / Q000737:chemistry; D015227:Lipid Peroxidation / Q000187:drug effects*; D008315:Malondialdehyde / Q000737:chemistry; D000069463:Olive Oil; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology*; D010626:Phenylethyl Alcohol / Q000031:analogs & derivatives / Q000737:chemistry; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology*; D024502:alpha-Tocopherol / Q000737:chemistry
chemical_list: D000975:Antioxidants; D005227:Fatty Acids; D016166:Free Radical Scavengers; D007653:Ketocholesterols; D000069463:Olive Oil; D010636:Phenols; D010938:Plant Oils; C005975:3,4-dihydroxyphenylethanol; C011867:4-hydroxyphenylethanol; D008315:Malondialdehyde; D002784:Cholesterol; D019787:Linoleic Acid; D024502:alpha-Tocopherol; D010626:Phenylethyl Alcohol; C003001:7-ketocholesterol