Studies of DNA Damage Inhibition by Dietary Antioxidants Using Metallopolyion/DNA Sensors

Abstract

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 Fentons 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.

Characterizing Metabolic Inhibition Using Electrochemical Enzyme/DNA Biosensors

“…The corresponding initial rates taken from the sensor ratio slopes for each inhibitor decreased with increased concentration (Figure 3). The observed changes in DNA damage signal were in good agreement with previous reports 21,32. Furthermore, liquid chromatography experiments with styrene, 500 µM inhibitors, and cyt P450cam in biocolloidal films confirmed inhibition of styrene oxide production (Figure 4).…”

“…Quartz crystal microbalance (QCM) measurements were used to validate film formation and determine amounts of DNA and cyt P450cam as previously reported 51,52. The DNA/CYP101 LBL films were incubated in a similar method as previously published with the exception of stirring the incubation solutions at ∼300 rpm during experiments and addition of inhibitors 21,28,29 . Safety note : Styrene and its metabolites are suspected carcinogens.…”

“…The required films can be made on single pyrolytic graphite electrodes (PG),17–19, 21–25,28,29 in a PG block array format,20,30 or on silica nanoparticles for product generation and LC-MS analysis 16,32. Studies conducted on these various biosensor formats include the metabolism and genotoxicity of styrene,17,19,22,27–29 benzo[a]pyrene,20 N-nitrosamines,16,30 and the genotoxicity of arylamines as activated by N-acetyltransferase 24,31.…”

Electrochemical detection of in situ DNA damage induced by enzyme-catalyzed Fenton reaction. Part I: in phosphate buffer solution

“…As a strong antioxidant, AA may markedly [50,51]. Figure 7 shows the influence of the antioxidant on the ratios of peak current before and after incubation in the cleavage agent.…”

Antioxidant Sensors Based on Iron Diethylenetriaminepentaacetic Acid, Hematin, and Hemoglobin Modified TiO2 Nanoparticle Printed Electrodes

“…9, [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39] ROS scavenging detection schemes were applied into these sensor techniques, and according to the radical species quenched, the sensor techniques can be classified into three groups: (I) OH radical scavenging, for example, the antioxidants compete against DNA for scavenging OH radicals generated chemically 9,24 or photochemically 25 at the electrode surfaces. DNA can be damaged by OH radicals, [6][7][8]11,[40][41][42][43][44] and the damaged DNA at the electrode surface gave lower DNA intercalant current signals. 24,25,[45][46][47][48] (II) Superoxide anion scavenging schemes where ROS were generated using the xanthine-xanthine oxidase system [26][27][28][29][30][31][32] or through the electrochemical reduction of dissolved oxygen at mercury electrode surfaces.…”