Differential protection by nitroxides and hydroxylamines to radiation-induced and metal ion-catalyzed oxidative damage

Sandhya Xavier, Ken Ichi Yamada, Ayelet M. Samuni, Amram Samuni, William DeGraff, Murali C. Krishna, James B. Mitchell

研究成果: Contribution to journalArticle査読

57 被引用数 (Scopus)


Modulation of radiation- and metal ion-catalyzed oxidative-induced damage using plasmid DNA, genomic DNA, and cell survival, by three nitroxides and their corresponding hydroxylamines, were examined. The antioxidant property of each compound was independently determined by reacting supercoiled DNA with copper II/1,10-phenanthroline complex fueled by the products of hypoxanthine/xanthine oxidase (HX/XO) and noting the protective effect as assessed by agarose gel electrophoresis. The nitroxides and their corresponding hydroxylamines protected approximately to the same degree (33-47% relaxed form) when compared to 76.7% relaxed form in the absence of protectors. Likewise, protection by both the nitroxide and corresponding hydroxylamine were observed for Chinese hamster V79 cells exposed to hydrogen peroxide. In contrast, when plasmid DNA damage was induced by ionizing radiation (100 Gy), only nitroxides (10 mM) provide protection (32.4-38.5% relaxed form) when compared to radiation alone or in the presence of hydroxylamines (10 mM) (79.8% relaxed form). Nitroxide protection was concentration dependent. Radiation cell survival studies and DNA double-strand break (DBS) assessment (pulse field electrophoresis) showed that only the nitroxide protected or prevented damage, respectively. Collectively, the results show that nitroxides and hydroxylamines protect equally against the damage mediated by oxidants generated by the metal ion-catalyzed Haber-Weiss reaction, but only nitroxides protect against radiation damage, suggesting that nitroxides may more readily react with intermediate radical species produced by radiation than hydroxylamines.

ジャーナルBiochimica et Biophysica Acta - General Subjects
出版ステータス出版済み - 11 14 2002

All Science Journal Classification (ASJC) codes

  • 生物理学
  • 生化学
  • 分子生物学


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