DNA Cleavage Induced by Oxyl Radicals Generated in the Photosensitized Decomposition of Fatty Ester Hydroperoxides Derived from Oleic and Linoleic Acid

Effect of Supplementation of n-3 Polyunsaturated Fatty Acids on Oxidative Stress-Induced DNA Damage of Rat Hepatocytes

“…1,2) One of the undesirable effects is considered to be lipid peroxidation-mediated DNA damage, because it has been shown that peroxidized PUFA induce DNA chain breaing [6][7][8][9][10] and 8-OHdG formation [11][12][13][14] in in vitro studies. It has not been known whether supplementation with high n-3 PUFA enhances oxidative stress-induced DNA damage.…”

“…The following mechanisms may explain the suppresion of oxidative stress-induced DNA damage by lipid peroxidation. Although lipid peroxidation products can damage DNA, [6][7][8][9][10][11][12][13][14] the potencies of lipid peroxidation products in damaging may be lower than those of direct oxidative stress due to reactive oxygen species. On the basis of the established concept, PUFA is converted by oxidative stress together with molecular oxygen into reactive peroxy radicals, which are in turn transformed into less reactive hydroperoxides and TBARS by the chain-breaking antioxidant system involving vitamin E. From the results obtained here, it is suggested that increased levels of hydroperoxides and TBARS as a consequence of scavenging oxidative stress may result in decreased levels of oxidative stress-induced DNA damage.…”

Superoxide Dismutase Enhanced the Formation of Hydroxyl Radicals in a Reaction Mixture Containing Xanthone under UVA Irradiation

“…Of the photosensitizers, xanthone and its derivatives have been extensively examined for UVA-induced DNA damage. 11,12) It has been found that xanthone mediates the photosensitized decomposition of fatty ester hydroperoxides to produce oxyl radicals 13) and hydroxyl radicals, 14,15) but to our knowledge, no study focusing on molecular oxygen-derived radicals has been performed. In this study, we detected hydroxyl radical and clarified the reaction mechanism in a reaction mixture of xanthone under UVA irradiation.…”

Suppression of Free Radical-Induced DNA Strand Breaks by Linoleic Acid and Low Density Lipoprotein in Vitro

“…The results were consistent with earlier ones showing that autoxidized or enzymatically synthesized lipid hydroperoxides caused DNA strand breaks in the presence of transition metal ions. [11][12][13][14][15] Inhibition by LDL of Ascorbic Acid/Cu(II) Ion-, Ascorbic Acid/Fe(III) Ion-, Peroxynitrite-and AAPH-Induced DNA Strand Breaks When pBR 322 DNA was incubated with 10 mM ascorbic acid/10 mM Cu(II) ion at 37°C for 2 h, form II DNA was produced (Fig. 6A, lane 2).…”

“…7) DNA damage is increased when the cells are treated with peroxidized lipids. [8][9][10] It has been clearly demonstrated that DNA strand breaks occurred [11][12][13][14][15] and 8-OHdG levels increased 16,17) in model systems in which naked DNA was treated with autoxidized or enzymatically synthesized and purified lipid hydroperoxides in the presence of trace amounts of transition metal ions.…”