title: Antioxidant properties of violacein: possible relation on its biological function.
abstract: Violacein, a violet pigment produced by Chromobacterium violaceum, has attracted much attention in recent literature due to its pharmacological properties. In this work, the antioxidant properties of violacein were investigated. The reactivity with oxygen and nitrogen reactive species and 1,1-diphenyl-2-picryl-hydrazyl (DPPH), a stable free radical, was evaluated. EPR studies were carried out to evaluate the reactivity with the hydroxyl radical. The action of violacein against lipid peroxidation in three models of lipid membranes, including rat liver microsomes, Egg and Soy bean phosphathidylcholine liposomes were also evaluated. The compound reacted with DPPH (IC(50)=30microM), nitric oxide (IC(50)=21microM), superoxide radicals (IC(50)=125microM) and decreased the hydroxyl radical EPR signal. The compound protected the studied membranes against peroxidation induced by reactive species in the micromolar range. The reconstitution of violacein into the membranes increased its antioxidant effect. These results indicate that the compound has strong antioxidant potential. Based on these results we suggest violacein plays an important role with the microorganism membrane in defense against oxidative stress.
authors.affiliation: Departamento de Ciências Farmacêuticas, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, CEP 88040-900, Florianópolis/SC, Brazil.
authors.forename: Marlon
authors.initials: M
authors.lastname: Konzen
authors.forename: Daniela
authors.initials: D
authors.lastname: De Marco
authors.forename: Clarissa A S
authors.initials: CA
authors.lastname: Cordova
authors.forename: Tiago O
authors.initials: TO
authors.lastname: Vieira
authors.forename: Regina V
authors.initials: RV
authors.lastname: Antônio
authors.forename: Tânia B
authors.initials: TB
authors.lastname: Creczynski-Pasa
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects; D004578:Electron Spin Resonance Spectroscopy; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006834:Hydrazines / Q000378:metabolism; D017665:Hydroxyl Radical / Q000378:metabolism; D007211:Indoles / Q000494:pharmacology*; D015227:Lipid Peroxidation; D008081:Liposomes / Q000378:metabolism; D008862:Microsomes, Liver / Q000187:drug effects; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress; D009195:Peroxidase / Q000378:metabolism; D010713:Phosphatidylcholines / Q000737:chemistry / Q000378:metabolism; D010851:Picrates; D051381:Rats; D013481:Superoxides / Q000378:metabolism
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D006834:Hydrazines; D007211:Indoles; D008081:Liposomes; D010713:Phosphatidylcholines; D010851:Picrates; D013481:Superoxides; D009569:Nitric Oxide; D017665:Hydroxyl Radical; C004931:1,1-diphenyl-2-picrylhydrazyl; D009195:Peroxidase; C063155:violacein