title: Prooxidant action of rosmarinic acid: transition metal-dependent generation of reactive oxygen species.
abstract: Rosmarinic acid and its constituent caffeic acid produced reactive oxygen species in the presence of transition metals. Complex of rosmarinic acid or caffeic acid with iron inactivated aconitase the most sensitive enzyme to oxidative stress. The inactivation of aconitase was iron-dependent, and prevented by TEMPOL, a scavenger of reactive oxygen species, suggesting that the rosmarinic acid/iron-mediated generation of superoxide anion is responsible for the inactivation of aconitase. Direct spectrophotometric determination of hydrogen peroxide and superoxide anion confirmed the rosmarinic acid/iron-dependent production of reactive oxygen species. Treatment of DNA from plasmid pBR322 and calf thymus with rosmarinic acid plus copper caused strand scission and formed 8-hydroxy-2'-deoxyguanosine in DNA. Rosmarinic acid and caffeic acid showed a potent activity that reduces transition metals. These results suggest that transition metals reduced by rosmarinic acid can form superoxide radical by one electron reduction of oxygen molecule: superoxide radical in turn converts to hydrogen peroxide and hydroxyl radical causing the formation of DNA base adduct. Cytotoxicity of rosmarinic acid may be related to the prooxidant action resulting from metal-reducing activity.
authors.affiliation: Department of Biochemistry, Aichi Medical University, School of Medicine, Nagakute, Aichi 480-1195, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Murakami
authors.forename: Miyako
authors.initials: M
authors.lastname: Haneda
authors.forename: Shanlou
authors.initials: S
authors.lastname: Qiao
authors.forename: Makoto
authors.initials: M
authors.lastname: Naruse
authors.forename: Masataka
authors.initials: M
authors.lastname: Yoshino
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000154:Aconitate Hydratase / Q000037:antagonists & inhibitors; D000975:Antioxidants / Q000737:chemistry; D002109:Caffeic Acids / Q000737:chemistry; D002847:Chromatography, Agarose; D002934:Cinnamates / Q000737:chemistry* / Q000494:pharmacology; D003300:Copper / Q000737:chemistry; D003497:Cyclic N-Oxides / Q000494:pharmacology; D004247:DNA / Q000187:drug effects; D018736:DNA Adducts / Q000737:chemistry; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000737:chemistry; D053630:Depsides / Q000737:chemistry* / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000737:chemistry; D016877:Oxidants / Q000737:chemistry* / Q000494:pharmacology; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000737:chemistry*; D013113:Spin Labels; D013481:Superoxides / Q000737:chemistry; D028561:Transition Elements / Q000494:pharmacology*; D000097123:Rosmarinic Acid
chemical_list: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000154:Aconitate Hydratase; D000975:Antioxidants; D002109:Caffeic Acids; D002934:Cinnamates; D003300:Copper; D003497:Cyclic N-Oxides; D004247:DNA; D018736:DNA Adducts; D003849:Deoxyguanosine; D053630:Depsides; D004791:Enzyme Inhibitors; D006861:Hydrogen Peroxide; D016877:Oxidants; D010100:Oxygen; D017382:Reactive Oxygen Species; D013113:Spin Labels; D013481:Superoxides; D028561:Transition Elements; D000097123:Rosmarinic Acid; C040048:caffeic acid; C001803:tempol