Studies of DNA damage inhibition by dietary antioxidants using metallopolyion/DNA sensors

Voltammetric sensors featuring thin-films containing osmium and ruthenium metallopolymers were evaluated to monitor the influence of antioxidants on DNA damage reactions. In the first example, apigenin, chrysin, and ascorbic acid were shown to inhibit oxidation of DNA by hydroxyl radicals generated with Fenton's reagent. A second example involved films of DNA with myoglobin (Mb) as an enzyme mimic which was used to convert styrene to styrene oxide. Here, the Ru peak of the sensor served as a marker of DNA damage from adduct formation between nucleobases and styrene oxide. There was no influence of the antioxidants on the reaction of styrene oxide itself with DNA films, but significant damage protection was afforded by micromolar amounts of antioxidants when styrene oxide was generated by Mb in the sensor films. This suggests that protection ensued from action of the antioxidants at the enzyme conversion level, probably by reduction of the active ferryloxy intermediate of the protein. Results demonstrate the usefulness of the thin metallopolyion/DNA film sensors in investigations of DNA damage inhibition.