A novel method using 8-hydroperoxy-2'-deoxyguanosine formation for evaluating antioxidative potency

Area of Science:

• Biochemistry
• Molecular Biology
• Nutritional Science

Background:

• Oxidative genetic damage from reactive oxygen species contributes to degenerative diseases like cancer.
• Effective antioxidants must neutralize reactive oxygen species rapidly to prevent DNA base damage.

Purpose of the Study:

• To develop and validate a novel method for evaluating the potency of dietary antioxidants.
• To assess the speed at which antioxidants scavenge reactive oxygen species before DNA damage occurs.
• To investigate the synergistic effects of combined antioxidants.

Main Methods:

• Established a new assay using 2'-deoxyguanosine as a target and 2,2'-azobis(2-amidino-propane) dihydrochloride to generate reactive oxygen species.
• Quantified the formation of 8-hydroperoxy-2'-deoxyguanosine (8-OOHdG) using high-performance liquid chromatography (HPLC).
• Assayed 81 dietary antioxidants for their ability to suppress 8-OOHdG formation and examined antioxidant synergism.

Main Results:

• The novel method successfully generated 8-OOHdG linearly with time, indicating a reliable measure of oxidative damage.
• The system demonstrated efficacy in evaluating antioxidative potency, showing advantages over the DPPH method.
• Ascorbic acid, quercetin, and epigallocatechin gallate exhibited additive synergistic effects in delaying 8-OOHdG formation.

Conclusions:

• The proposed method is a simple and effective tool for assessing the rapid action of dietary antioxidants against reactive oxygen species.
• This assay can differentiate the protective capacities of various antioxidants, identifying those that act most quickly.
• Understanding antioxidant speed and synergy is crucial for preventing DNA damage and related degenerative diseases.