title: Complexes trans-[RuCl(2)(nic)(4)] and trans-[RuCl(2)(i-nic)(4)] as free radical scavengers.
abstract: This study evaluates the action of the new ruthenium complexes trans-RuCl(2)(nic)(4)] (I) and trans-[RuCl(2)(i-nic)(4)] (II) as free radical scavengers. In our experiments, both compounds acted as scavengers of superoxide anion (O(2)*(-)), hydroxyl radicals (HO*) and nitrogen monoxide (formally known as 'nitric oxide'; NO*). In addition, complexes I and II potentiated the release of NO* from S-nitroso-N-acetyl-DL-penicilamine (SNAP), a NO* donor. Complex II, but not I, also decreased the nitrite levels in culture media of activated macrophages. A hypsochromic shift of lambda(max) and a significant change in half-wave potential (E(1/2)) was observed when NO* was added to the Complex II. Thiobarbituric reactive substance (TBARS) levels were significantly reduced in rats treated for 1 week with Complex II plus tert-butylhydroperoxide, when compared to rats treated only with tert-butylhydroperoxide. None of the complexes showed cytotoxicity. These findings support the suggestion that the new ruthenium complexes, especially trans-[RuCl(2)(i-nic)(4)] or its derivatives, might provide potential therapeutic benefits in disorders where reactive nitrogen (RNS) or oxygen (ROS) species are involved.
authors.affiliation: Department of Physiology and Biophysics, Federal University of Santa Catarina, CP476, 88049-900, Florianópolis, SC, Brazil. taniac@mboxl.ufsc.br
authors.forename: T B
authors.initials: TB
authors.lastname: Creczynski-Pasa
authors.forename: V R
authors.initials: VR
authors.lastname: Bonetti
authors.forename: A
authors.initials: A
authors.lastname: Beirith
authors.forename: K
authors.initials: K
authors.lastname: Ckless
authors.forename: M
authors.initials: M
authors.lastname: Konzen
authors.forename: I
authors.initials: I
authors.lastname: Seifriz
authors.forename: M S
authors.initials: MS
authors.lastname: Paula
authors.forename: C V
authors.initials: CV
authors.lastname: Franco
authors.forename: D
authors.initials: D
authors.lastname: Wilhelm Filho
authors.forename: J B
authors.initials: JB
authors.lastname: Calixto
mesh_terms: D000818:Animals; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000494:pharmacology*; D017665:Hydroxyl Radical / Q000378:metabolism; D066298:In Vitro Techniques; D007539:Isonicotinic Acids / Q000737:chemistry* / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D009539:Nicotinic Acids / Q000737:chemistry* / Q000494:pharmacology*; D009569:Nitric Oxide / Q000378:metabolism; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009942:Organometallic Compounds / Q000737:chemistry* / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D026361:Reactive Nitrogen Species / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D012428:Ruthenium / Q000737:chemistry*; D026423:S-Nitroso-N-Acetylpenicillamine / Q000494:pharmacology; D013481:Superoxides / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D016166:Free Radical Scavengers; D007539:Isonicotinic Acids; D009539:Nicotinic Acids; D020030:Nitric Oxide Donors; D009942:Organometallic Compounds; D026361:Reactive Nitrogen Species; D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances; C440900:dichlorotetrakis(isonicotinic acid)ruthenium(II); C440899:dichlorotetrakis(nicotinic acid)ruthenium(II); D013481:Superoxides; D009569:Nitric Oxide; D017665:Hydroxyl Radical; D026423:S-Nitroso-N-Acetylpenicillamine; D012428:Ruthenium