title: Protection of flavonoids against hypochlorite-induced protein modifications.
abstract: Plant polyphenols, such as flavonoids, are ubiquitous components of human diet, and have been recognised as efficient radical scavengers and antioxidants. Their protective effects were especially seen in cell-free assays. Whilst in living cells, depending on experimental conditions, polyphenols may manifest both anti- and pro-oxidative activity. In the present study, the effectiveness of fifteen structurally different flavonoids against hypochlorite-mediated changes in in vitro systems, with and without cells, was tested and compared. Quercetin was found to be the best protector against hypochlorite-mediated fluorescein bleaching and BSA thiol groups oxidation, whilst in living cells its effects on hypochlorite-associated cytotoxicity were moderate. Contrary, epigallocatechin gallate, pelargonidin and catechin, with less impressive hypochlorite scavenging activity in cell-free assays, were the most effective against 3-chlorotyrosine formation after hypochlorite treatment. Taken together, special care should be taken when extrapolating the results on antioxidant propensity of food bioactive compounds in vitro to the cellular milieu.
authors.affiliation: Department of Genetics, University of Rzeszow, Werynia 502, 36-100 Kolbuszowa, Poland.
authors.forename: Justyna
authors.initials: J
authors.lastname: Siwak
authors.forename: Anna
authors.initials: A
authors.lastname: Lewinska
authors.forename: Maciej
authors.initials: M
authors.lastname: Wnuk
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Bartosz
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D002460:Cell Line; D002477:Cells / Q000187:drug effects / Q000378:metabolism; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D006997:Hypochlorous Acid / Q000737:chemistry* / Q000633:toxicity; D010084:Oxidation-Reduction / Q000187:drug effects; D012710:Serum Albumin, Bovine / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D012710:Serum Albumin, Bovine; D006997:Hypochlorous Acid