Antioxidant properties of violacein: Possible relation on its biological function

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 (IC50 = 30 μM), nitric oxide (IC50 = 21 μM), superoxide radicals (IC50 = 125 μM) 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.

Chromobacterium violaceum has attracted much attention in recent literature due to its genome elucidation. In this work we report violacein (a pigment produced by the bacterium) antioxidant efficiency against oxygen and nitrogen reactive species and to inhibit the myeloperoxidase (MPO) activity. Additionally we show that violacein reconstituted into liposomes has its antioxidant potential increased. We suggest a possible role of the pigment for the microorganism.Figure optionsDownload as PowerPoint slide