title: Protection of human HepG2 cells against oxidative stress by cocoa phenolic extract.
abstract: Cocoa is a rich source of flavanols and procyanidin oligomers with antioxidative properties, providing protection against oxidation and nitration. The present study investigated the potential protective effect of a polyphenolic extract from cocoa on cell viability and antioxidant defenses of cultured human HepG2 cells submitted to oxidative stress induced by tert-butylhydroperoxide (t-BOOH). Pretreatment of cells with 0.05-50 microg/mL of cocoa polyphenolic extract (CPE) for 2 or 20 h completely prevented cell damage and enhanced activity of antioxidant enzymes induced by a treatment with t-BOOH. Moreover, lower levels of GSH caused by t-BOOH in HepG2 cells were partly recovered by a pretreatment with CPE. Increased reactive oxygen species (ROS) induced by t-BOOH was dose-dependently prevented when cells were pretreated for 2 or 20 h with CPE. These results show that treatment of HepG2 in culture with CPE (within the physiological range of concentrations) confers a significant protection against oxidation to the cells.
authors.affiliation: Department of Metabolism and Nutrition Instituto del Frío, Consejo Superior de Investigaciones Científicas, José Antonio Novais 10, 28040 Madrid, Spain.
authors.forename: María Angeles
authors.initials: MA
authors.lastname: Martín
authors.forename: Sonia
authors.initials: S
authors.lastname: Ramos
authors.forename: Raquel
authors.initials: R
authors.lastname: Mateos
authors.forename: Ana Belén
authors.initials: AB
authors.lastname: Granado Serrano
authors.forename: María
authors.initials: M
authors.lastname: Izquierdo-Pulido
authors.forename: Laura
authors.initials: L
authors.lastname: Bravo
authors.forename: Luis
authors.initials: L
authors.lastname: Goya
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D002099:Cacao / Q000737:chemistry*; D002460:Cell Line; D005419:Flavonoids / Q000032:analysis / Q000302:isolation & purification* / Q000494:pharmacology*; D006801:Humans; D018384:Oxidative Stress / Q000187:drug effects*; D010636:Phenols / Q000032:analysis / Q000302:isolation & purification* / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry*; D059808:Polyphenols; D013805:Theobromine / Q000494:pharmacology; D020122:tert-Butylhydroperoxide / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; D059808:Polyphenols; D020122:tert-Butylhydroperoxide; D013805:Theobromine