Electrocatalytic evaluation of DNA damage by superoxide radical for antioxidant capacity assessment

Abstract

a b s t r a c tThe integrity of DNA purine bases was herein used to evaluate the antioxidant capacity. Unlike other DNA-based antioxidant sensors reported so far, the damaging agent chosen was the O ÅÀ 2 radical enzymatically generated by the xanthine/xanthine oxidase system. An adenine-rich oligonucleotide was adsorbed on carbon paste electrodes and subjected to radical damage in the presence/absence of several antioxidant compounds. As a result, partial damage on DNA was observed. A minor product of the radical oxidation was identified by cyclic voltammetry as a diimine adenine derivative also formed during the electrochemical oxidation of adenine/guanine bases. The protective efficiency of several antioxidant compounds was evaluated after electrochemical oxidation of the remaining unoxidized adenine bases, by measuring the electrocatalytic current of NADH mediated by the adsorbed catalyst species generated. A comparison between O ÅÀ 2 and OH Å radicals as a source of DNA lesions and the scavenging efficiency of various antioxidant compounds against both of them is discussed. Finally, the antioxidant capacity of beverages was evaluated and compared with the results obtained with an optical method.

Antioxidant and Free Radical-Scavenging Potential of Essential Oil from E nteromorpha linza L. Prepared by Microwave-Assisted Hydrodistillation

“…Superoxide is responsible for the formation of other ROS such as singlet oxygen and hydroxyl radical, which cause serious damage to proteins, lipids and DNA (Barroso et al . ).…”

“…The superoxide anion is one of the most common free radicals generated under in vivo conditions, and its concentration increases drastically under oxidative stress in all cells because of its transformation into more reactive species (Gulcin et al 2010). Superoxide is responsible for the formation of other ROS such as singlet oxygen and hydroxyl radical, which cause serious damage to proteins, lipids and DNA (Barroso et al 2011).…”

Electrochemical DNA Biosensors in Food Safety: Determination of Phenolic Compounds and Antioxidant Capacity in Foods and Beverages

“…Thus, the superoxide anion radical able to specifically oxidize adenine to diimine products has been obtained in the enzymatic reaction of xanthine oxidase (Equation 25.7) [69]. Voltammetric detection of the DNA sensor response was performed by addition of NADH/Ca 2+ to the working solution.…”

MICROWAVE-ASSISTED SEED ESSENTIAL OIL OF ELEUTHEROCOCCUS SENTICOSUS AND ITS ANTIOXIDANT AND FREE RADICAL-SCAVENGING ACTIVITIES

“…Superoxide radical, a reduced form of molecular oxygen, has been implicated in initiating oxidation reactions associated with aging (Sohala and Orr 2012). Superoxide radicals play an important role in formation of other ROS such as singlet oxygen (O2), hydrogen peroxide and hydroxyl radical, which cause serious damage in DNA, lipids and proteins (Barroso et al 2011). The superoxide anion is produced by a number of enzymatic and nonenzymatic electron transfer reactions that univalently reduce molecular oxygen.…”