Penabeï Samafou, Meesungnoen Jintana, Jay-Gerin Jean-Paul
Département de Médecine Nucléaire et de Radiobiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, 3001, 12ème Avenue Nord, Sherbrooke, QC J1H 5N4, Canada.
Antioxidants (Basel). 2023 Mar 22;12(3):776. doi: 10.3390/antiox12030776.
(1) Background: cystamine and its reduced form cysteamine have radioprotective/antioxidant effects in vivo. In this study, we use an in vitro model system to examine the behavior of cystamine towards the reactive primary species produced during the radiolysis of the Fricke dosimeter under high dose-rate irradiation conditions. (2) Methods: our approach was to use the familiar radiolytic oxidation of ferrous to ferric ions as an indicator of the radioprotective/antioxidant capacity of cystamine. A Monte Carlo computer code was used to simulate the multi-track radiation-induced chemistry of aerated and deaerated Fricke-cystamine solutions as a function of dose rate while covering a large range of cystamine concentrations. (3) Results: our simulations revealed that cystamine provides better protection at pulsed dose rates compared to conventional, low-dose-rate irradiations. Furthermore, our simulations confirmed the radical-capturing ability of cystamine, clearly indicating the strong antioxidant profile of this compound. (4) Conclusion: assuming that these findings can be transposable to cells and tissues at physiological pH, it is suggested that combining cystamine with FLASH-RT could be a promising approach to further enhance the therapeutic ratio of cancer cure.
(1) 背景：胱胺及其还原形式半胱胺在体内具有辐射防护/抗氧化作用。在本研究中，我们使用体外模型系统来研究在高剂量率照射条件下，胱胺对弗里克剂量计辐射分解过程中产生的活性初级物种的作用。(2) 方法：我们的方法是利用亚铁离子到铁离子的常见辐射氧化反应作为胱胺辐射防护/抗氧化能力的指标。使用蒙特卡罗计算机代码来模拟充氧和脱氧的弗里克 - 胱胺溶液在不同剂量率下的多径迹辐射诱导化学过程，同时涵盖大范围的胱胺浓度。(3) 结果：我们的模拟结果表明，与传统的低剂量率照射相比，胱胺在脉冲剂量率下提供了更好的防护。此外，我们的模拟证实了胱胺的自由基捕获能力，清楚地表明了该化合物强大的抗氧化特性。(4) 结论：假设这些发现能够在生理pH条件下转化到细胞和组织中，建议将胱胺与FLASH - RT相结合可能是进一步提高癌症治疗疗效比的一种有前景的方法。
