Measuring hydrogen peroxide reduction using a robust, inexpensive, and sensitive method

Abstract

Here, we report an improved method to analyze antioxidant activity using the europium tetracycline assay developed by Duerkop and Wolfbeis (J Fluor 15(5):755-761, 2005). The europium tetracycline hydrogen peroxide reduction assay (EHRA) accurately measures antioxidant activity based on hydrogen peroxide scavenging. Several known antioxidant compounds were assessed with the EHRA and a stoichiometric relationship between the number of oxidant molecules trapped per molecule of antioxidant was identified. Various extracts of hops were also tested to validate this method for use with natural extracts; water extraction yielded the highest level of antioxidant activity. Hop leaves were shown to be a better source of antioxidants relative to the traditional hop cones. The data also indicate that the EHRA may serve to breach the hydrophilic/lipophilic gap in antioxidant screening as the europium tetracycline probe is effective in many solvents. The EHRA thus provides a robust and inexpensive measure of antioxidant activity.

First Evidence of a Protective Effect of Plant Bioactive Compounds against H2O2-Induced Aconitase Damage in Durum Wheat Mitochondria

“…A direct H 2 O 2 scavenging activity of the investigated compounds is undoubtedly involved. With respect to this point, the capability to efficiently scavenge H 2 O 2 is widely known for the tested phenolic compounds, including ferulic acid, quercetin, resveratrol, and curcumin [ 9 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 ]. Moreover, in accordance with their high reducing activity against the ABTS∙ + radical cation, the capability of the investigated phytochemicals to act as reducing agents, which are reported to be capable of maintaining the reducing groups of the protein and the iron in the reduced state [ 62 ], cannot be excluded under the applied experimental conditions.…”