Polyphenolic prevention of deoxyribose damage using spectroscopic methods

Hydroxyl radical formation via Fe2+/Cu+ metal leads to oxidative DNA damage that is implicated in a number of neurodegenerative and cardiovascular diseases such as Parkinson’s diseases and atherosclerosis. Specifically, oxidative stress can lead to strand breaks and other DNA damage. Antioxidants can prevent this damage through metal binding and radical scavenging mechanisms. Polyphenols are one class of abundant antioxidants shown to provide protection against radical species and are found in foods such as fruits, nuts, and berries. Therefore, polyphenol compounds were tested for their ability to prevent deoxyribose degradation by iron and hydrogen peroxide using the deoxyribose assay, a low-cost, screening method that measures the formation of malondialdehyde (MDA), a byproduct of degraded deoxyribose, using ultraviolet-visible (UV-vis) spectroscopy. Previous studies showed low reproducibility when reporting deoxyribose damage prevention by antioxidants. Using a newly modified deoxyribose assay in the Brumaghim lab that improves reproducibility, quinolinic acid and four polyphenols (MEGA, MEPCA, PrEGA, and PCA) were tested for their antioxidant abilities. These results were compared to polyphenol prevention of plasmid DNA damage by iron and hydrogen peroxide using gel electrophoresis, a method that uses DNA as the substrate but is lower-throughput. Compared to plasmid DNA damage prevention, MEGA, MEPCA, PrEGA, and PCA, show greater deoxyribose damage prevention using the deoxyribose assay. Relating antioxidant activity measurements between these two methods enables accurate use of the deoxyribose assay as a higher-throughput method for determining DNA damage or its inhibition compared to DNA gel electrophoresis methods