title: Antioxidant effectiveness of phenolic apple juice extracts and their gut fermentation products in the human colon carcinoma cell line caco-2.
abstract: Apples represent a major dietary source of antioxidative polyphenols. Their metabolic conversion by the gut microflora might generate products that protect the intestine against oxidative damage. We studied the antioxidant effectiveness of supernatants of fermented apple juice extracts (F-AEs, 6 and 24 h fermentation) and of selected phenolic degradation products, identified by HPLC-DAD-ESI-MS. Cell free antioxidant capacity of unfermented apple juice extracts (AEs) was decreased after fermentation by 30-50%. In the human colon carcinoma cell line Caco-2, F-AEs (containing <0.5% of original AE-phenolics) decreased the reactive oxygen species (ROS) level more efficiently than the F-blank (fermented without AE) but were less effective than the respective AEs. Similarly, antioxidant effectiveness of individual degradation products was lower compared to respective AE constituents. Glutathione level was slightly increased and oxidative DNA damage slightly decreased by fermented AE03, rich in quercetin glycosides. In conclusion, F-AEs/degradation products exhibit antioxidant activity in colon cells but to a lesser extent than the respective unfermented AEs/constituents.
authors.affiliation: Division of Food Chemistry and Toxicology, Department of Chemistry, University of Kaiserslautern, Erwin-Schroedinger-Str. 52, D-67663 Kaiserslautern, Germany.
authors.forename: Phillip
authors.initials: P
authors.lastname: Bellion
authors.forename: Thomas
authors.initials: T
authors.lastname: Hofmann
authors.forename: Beatrice L
authors.initials: BL
authors.lastname: Pool-Zobel
authors.forename: Frank
authors.initials: F
authors.lastname: Will
authors.forename: Helmut
authors.initials: H
authors.lastname: Dietrich
authors.forename: Bastian
authors.initials: B
authors.lastname: Knaup
authors.forename: Elke
authors.initials: E
authors.lastname: Richling
authors.forename: Matthias
authors.initials: M
authors.lastname: Baum
authors.forename: Gerhard
authors.initials: G
authors.lastname: Eisenbrand
authors.forename: Christine
authors.initials: C
authors.lastname: Janzowski
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D018938:Caco-2 Cells; D003106:Colon / Q000737:chemistry / Q000378:metabolism* / Q000382:microbiology; D004249:DNA Damage / Q000187:drug effects; D005285:Fermentation; D005638:Fruit / Q000737:chemistry*; D006801:Humans; D027845:Malus / Q000737:chemistry*; D010936:Plant Extracts / Q000378:metabolism / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000032:analysis
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D017382:Reactive Oxygen Species