title: Study of interactions between phenolic compounds and H2O2 or Cu(II) ions in B14 Chinese hamster cells.
abstract: The antioxidant and prooxidant effects of tannic, ellagic and gallic acids (1-60 microM) in the presence of hydrogen peroxide (40 and 100 microM) or copper ions (50 microM) on B14 Chinese hamster cells were examined. The fluorescence probe DCFH-DA (dichlorofluorescein-diacetate) was used to analyse the levels of reactive oxygen species. This method showed the reduction in oxidation of DCF (dichlorofluorescein). It indicates that antioxidant capacity of tested polyhenols is decreased in the presence of hydrogen peroxide or copper ions. Spectrophotometric assay with Ellman's reagent was used to determine SH-groups. The experimental results revealed the oxidative modification of proteins after exposure to polyphenols at concentrations above 15 microM. Additional incubation with H2O2 or Cu(2+) ions showed the prooxidant activity of tested complexes also for polyphenols used at a concentration of 1 microM. Fluorescence method with Hoechst 33258/propidium iodide dyes was used to study apoptotic and necrotic cell death. The obtained data demonstrated that polyphenols alone, as well as in the presence of hydrogen peroxide or copper ions, can induce DNA fragmentation.
authors.affiliation: Institute of Biophysics, Department of General Biophysics, University of Lodz, 12/16 Banacha Street, 90-237 Lodz, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Labieniec
authors.forename: Teresa
authors.initials: T
authors.lastname: Gabryelak
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003300:Copper / Q000494:pharmacology*; D006224:Cricetinae; D003412:Cricetulus; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D004610:Ellagic Acid / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology*; D005707:Gallic Acid / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007477:Ions / Q000494:pharmacology; D009336:Necrosis / Q000139:chemically induced; D016877:Oxidants / Q000494:pharmacology; D010636:Phenols / Q000494:pharmacology*; D059808:Polyphenols; D013438:Sulfhydryl Compounds / Q000032:analysis; D013634:Tannins / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D004338:Drug Combinations; D005419:Flavonoids; D007477:Ions; D016877:Oxidants; D010636:Phenols; D059808:Polyphenols; D013438:Sulfhydryl Compounds; D013634:Tannins; D004610:Ellagic Acid; D005707:Gallic Acid; D003300:Copper; D006861:Hydrogen Peroxide