Department of Engineering Physics, Tsinghua University, Beijing, China.
Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, China.
Int J Radiat Biol. 2024;100(4):595-608. doi: 10.1080/09553002.2023.2295292. Epub 2024 Jan 2.
Oxygen plays a crucial role in radiation biology. Antioxidants and peroxyl radicals affect the oxygen effect greatly. This study aims to establish a computational model of the oxygen effect and explore the effect attributed to antioxidants and peroxyl radicals.
Oxygen-related reactions are added to our track-structure Monte Carlo code NASIC, including oxygen fixation, chemical repair by antioxidants and damage migration from base-derived peroxyl radicals. Then the code is used to simulate the DNA damage under various oxygen, antioxidant and damage migration rate conditions. The oxygen enhancement ratio(OER) is calculated quantifying by the number of double-strand breaks for each condition. The roles of antioxidants and peroxyl radicals are examined by manipulating the relevant parameters.
Our results indicate that antioxidants are capable of rapidly restoring DNA radicals through chemical reactions, which compete with natural and oxygen fixation processes. Additionally, antioxidants can react with peroxyl radicals derived from bases, thereby preventing the damage from migrating to DNA strands. By quantitatively accounting for the impact of peroxyl radicals and antioxidants on the OER curves, our study establishes a more precise and comprehensive model of the radiation oxygen effect.
氧在放射生物学中起着至关重要的作用。抗氧化剂和过氧自由基对氧效应有很大影响。本研究旨在建立氧效应的计算模型，并探讨抗氧化剂和过氧自由基的作用。
将与氧有关的反应添加到我们的轨道结构蒙特卡罗代码 NASIC 中，包括氧固定、抗氧化剂的化学修复以及碱基衍生的过氧自由基的损伤迁移。然后，该代码用于模拟各种氧、抗氧化剂和损伤迁移率条件下的 DNA 损伤。通过计算每种条件下双链断裂的数量来定量计算氧增强比（OER）。通过操纵相关参数来研究抗氧化剂和过氧自由基的作用。
我们的结果表明，抗氧化剂能够通过化学反应迅速恢复 DNA 自由基，从而与自然和氧固定过程竞争。此外，抗氧化剂可以与碱基衍生的过氧自由基反应，从而防止损伤迁移到 DNA 链上。通过定量考虑过氧自由基和抗氧化剂对 OER 曲线的影响，我们的研究建立了一个更精确和全面的辐射氧效应模型。
