Anthocyanin-DNA copigmentation complex: mutual protection against oxidative damage

The absorption spectra of a cyanidin derivative showed a 15-20 nm bathochromic shift when mixed with calf thymus DNA (ctDNA), indicating formation of a cyanidin-DNA copigmentation complex. Exposure of either cyanidin or ctDNA individually to hydroxyl radicals (OH.) obtained in the Fenton reaction between ferrous ions and hydrogen peroxide caused severe oxidative damage. However, formation of cyanidin-DNA complex prior to exposure to OH. protected both the cyanidin and ctDNA from the oxidative damage. These results suggest that cyanidin-DNA copigmentation might be a possible defense mechanism against oxidative damage of DNA and may have in vivo physiological function attributable to the antioxidant ability of anthocyanins. (C) 1999 Elsevier Science Ltd. All rights reserved.