title: Antioxidant properties of aminoguanidine.
abstract: It is well known that aminoguanidine (AG) can diminish advanced glycosylation of proteins, which might be beneficial in preventing chronic diabetic complications. Recent reports suggested an inter-relationship between glycosylation of protein and free radical damage. In the present study, we examined the free radical scavenging properties of AG. Electron paramagnetic resonance using the spin-trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO) was performed to determine the superoxide and hydroxyl radical scavenging abilities of AG. These experiments revealed that AG was an effective hydroxyl radical scavenger even though it expressed a direct inhibitory effect on the xanthine oxidase activity at high concentrations (AG > or = 5 mM). In the second part of the study, allophycocyanin was used as an indicator of free radical mediated protein damage. In the assay, 2,2'-azobis(2-amidinopropane) hydrochloride (AAPH) was used as a peroxyl radical generator, and the loss of allophycocyanin fluorescence was monitored. The antioxidant effect of AG was expressed in oxygen-radical absorbing capacity (ORAC), where one ORAC unit equals the net protection produced by 1 microM Trolox (a water soluble analogue of vitamin E) as a control standard. AG exhibited a significant dose-dependent effect against free radical damage. These radical scavenging properties of AG may contribute to protective effects during glycation and explain the prevention of diabetic complications.
authors.affiliation: LPPCE, Facultés de Médecine et Pharmacie, Dijon, France.
authors.forename: C
authors.initials: C
authors.lastname: Courderot-Masuyer
authors.forename: F
authors.initials: F
authors.lastname: Dalloz
authors.forename: V
authors.initials: V
authors.lastname: Maupoil
authors.forename: L
authors.initials: L
authors.lastname: Rochette
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D003497:Cyclic N-Oxides / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D004578:Electron Spin Resonance Spectroscopy; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D005453:Fluorescence; D006146:Guanidines / Q000737:chemistry / Q000494:pharmacology*; D017665:Hydroxyl Radical / Q000737:chemistry / Q000378:metabolism; D010798:Phycocyanin / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D013113:Spin Labels; D019097:Spin Trapping; D014969:Xanthine Oxidase / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism
chemical_list: D000975:Antioxidants; D003497:Cyclic N-Oxides; D004791:Enzyme Inhibitors; D006146:Guanidines; D013113:Spin Labels; C002497:allophycocyanin; D010798:Phycocyanin; D017665:Hydroxyl Radical; C017245:5,5-dimethyl-1-pyrroline-1-oxide; D014969:Xanthine Oxidase; C004479:pimagedine