title: Protection of human HepG2 cells against oxidative stress by the flavonoid epicatechin.
abstract: Flavanols, such as epicatechin (EC), constitute an important part of the human diet; they can be found in green tea, grapes and cocoa and possess different biological activities such as antioxidant, anti-inflammatory and anticarcinogenic. This study investigated the potential chemo-protective effect of EC against oxidative stress induced by tert-butylhydroperoxide (t-BOOH) on human HepG2 cells. Cell viability by lactate dehydrogenase assay and markers of oxidative status: reduced glutathione (GSH), malondialdehyde (MDA), reactive oxygen species (ROS), glutathione peroxidase (GPx) and glutathione reductase (GR) were evaluated. Pretreatment of cells with EC for 20 h prevented the enhanced cell damage and GPx and GR activities as well as the decrease in GSH induced by t-BOOH. The increased ROS generation induced by t-BOOH was also partly prevented by a pretreatment for 20 h with EC. In addition, pretreatment of cells with EC for 20 h recovered the t-BOOH-induced MDA concentration to control values. A pretreatment for 2 h with EC did not reduce cell damage but partly recovered GSH, reduced ROS levels and muffled the increase of GPx and GR after exposure to t-BOOH. Treatment of HepG2 cells with concentrations of EC in the micromolar range confers a significant protection against oxidative stress.
authors.affiliation: Departamento de Metabolismo y Nutrición Instituto del Frío-ICTAN (CSIC), 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: 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 / Q000378:metabolism; D002392:Catechin / Q000378:metabolism / Q000494:pharmacology*; D002470:Cell Survival; D004353:Drug Evaluation, Preclinical; D005978:Glutathione / Q000378:metabolism; D056945:Hep G2 Cells; D006801:Humans; D015227:Lipid Peroxidation; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D020122:tert-Butylhydroperoxide
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D002392:Catechin; D020122:tert-Butylhydroperoxide; D005978:Glutathione