Health Research Institute, National Institute of Advanced Industrial Science and Technology, Ikeda, Osaka 563-8577, Japan.
Free Radic Biol Med. 2012 Apr 1;52(7):1242-52. doi: 10.1016/j.freeradbiomed.2012.01.010. Epub 2012 Jan 28.
With increasing evidence showing the involvement of oxidative stress induced by free radicals in the development of various diseases, the role of radical-scavenging antioxidants has received much attention. Although many randomized controlled clinical trials do not support the beneficial effects of indiscriminate supplementation of antioxidants, more recent studies suggest that antioxidants such as vitamin E may be effective for prevention and treatment of some diseases when given to the right subjects at the right time. Many studies on the antioxidant capacity assessed by various available methods showed inconsistent results and the assessment of antioxidant capacity has been the subject of extensive studies and arguments. This study was performed to elucidate the basic chemistry required for the development of a reliable method for the assessment of antioxidant capacity for radical scavenging in vitro. In this study, the capacity of α-tocopherol and its related compounds, ascorbic acid, and uric acid for scavenging radicals was assessed from their effects on the rate of decay of hydrophilic and lipophilic probes with various reactivities toward free radicals induced by hydrophilic and lipophilic radicals in homogeneous solution and heterogeneous micelle systems. Fluorescein, pyranine, and pyrogallol red were used as hydrophilic probes, and BODIPY and N,N-diphenyl-p-phenylenediamine were used as lipophilic probes. We show that the rate and amount of radical scavenging by antioxidants, termed the antioxidant radical absorbance capacity, could be assessed by an appropriate combination of radical initiator and probe. This method was applied to the assessment of radical-scavenging capacity of human plasma, wine, and green tea powder.
随着越来越多的证据表明自由基诱导的氧化应激在各种疾病的发展中起作用，自由基清除抗氧化剂的作用受到了广泛关注。尽管许多随机对照临床试验不支持不分青红皂白地补充抗氧化剂的有益效果，但最近的研究表明，当在适当的时间给予适当的受试者时，维生素 E 等抗氧化剂可能对某些疾病的预防和治疗有效。许多使用各种现有方法评估抗氧化能力的研究显示出不一致的结果，并且抗氧化能力的评估一直是广泛研究和争论的主题。本研究旨在阐明开发可靠的体外自由基清除抗氧化能力评估方法所需的基本化学知识。在这项研究中，从α-生育酚及其相关化合物、抗坏血酸和尿酸清除自由基的能力，评估它们对亲水性和疏水性探针在均相溶液和异相胶束体系中由亲水性和疏水性自由基诱导的各种反应性自由基衰减速率的影响。荧光素、吡喃和焦性没食子酸红被用作亲水性探针，BODIPY 和 N，N-二苯基-p-苯二胺被用作疏水性探针。我们表明，抗氧化剂的自由基清除速率和量，称为抗氧化剂自由基吸收能力，可以通过适当的自由基引发剂和探针组合来评估。该方法应用于评估人血浆、葡萄酒和绿茶粉的自由基清除能力。
