title: Effects of iron on Vitamin C/copper-induced hydroxyl radical generation in bicarbonate-rich water.
abstract: The aim of this study was to evaluate whether iron, like copper, could support Vitamin C mediated hydroxyl radical formation in bicarbonate-rich water. By using the hydroxyl radical indicator coumarin-3-carboxylic acid, we found that iron, in contrast to copper, was not capable to support Vitamin C induced hydroxyl radical formation. However, when 0.2 mg/l iron and 0.1 mg/l copper were both added to bicarbonate supplemented Milli-Q water, the Vitamin C induced formation of 7-hydroxycoumarin, as measured by HPLC analysis, was inhibited by 47.5%. The inhibition of hydroxyl radical formation by iron was also evident in the experiments performed on copper contaminated bicarbonate-rich household drinking water samples. In the presence of 0.2 mg/l of ferric iron the ascorbic acid induced hydroxyl radical formation was inhibited by 36.0-44.6%. This inhibition was even more significant, 47.0-59.2%, when 0.8 mg/l of ferric iron was present. None of the other redox-active metals, e.g. manganese, nickel or cobalt, could support ascorbic acid induced hydroxyl radical formation and did not have any impact on the ascorbic acid/copper-induced hydroxyl radical generation. Our results show, that iron cannot by itself produce hydroxyl radicals in bicarbonate rich water but can significantly reduce Vitamin C/copper-induced hydroxyl radical formation. These findings might partly explain the mechanism for the iron-induced protective effect on various copper related degenerative disorders that earlier has been observed in animal model systems.
authors.affiliation: Department of Biochemistry and Pharmacy, Abo Akademi University, BioCity, P.O. Box 66, 20521, Turku, Finland.
authors.forename: Patric J
authors.initials: PJ
authors.lastname: Jansson
authors.forename: Urko
authors.initials: U
authors.lastname: Del Castillo
authors.forename: Christer
authors.initials: C
authors.lastname: Lindqvist
authors.forename: Tommy
authors.initials: T
authors.lastname: Nordström
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry*; D001639:Bicarbonates / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D003300:Copper / Q000737:chemistry*; D005506:Food Contamination; D017665:Hydroxyl Radical / Q000032:analysis / Q000138:chemical synthesis*; D007501:Iron / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D001639:Bicarbonates; D014867:Water; D017665:Hydroxyl Radical; D003300:Copper; D007501:Iron; D001205:Ascorbic Acid