Antioxidants: basic principles, emerging concepts, and problems.
Antioxidants: basic principles, emerging concepts, and problems.
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DOI：
10.4103/2319-4170.128727
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发表时间：
2014-05-01
影响因子：
5.5
通讯作者：
Niki, Etsuo
中科院分区：
文献类型：
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作者：
Niki, Etsuo
自由基清除抗氧化剂在维护健康和预防疾病方面起着至关重要的作用，深入了解抗氧化剂的作用和能力至关重要。尽管假设抗氧化剂必须对氧化应激发挥有益作用，但许多大规模随机对照试验在预防慢性疾病方面的结果不一致且令人失望。现在人们普遍认为，没有证据支持使用非歧视性的抗氧化剂补充剂来预防疾病。另一方面，最近的数据表明，当在正确的时间给予正确的受试者正确的抗氧化剂时，抗氧化剂可以有效地预防和/或治疗疾病。活性氧（reactive oxygen species，ROS）是一种重要的信号分子，也是一种有害物质。信号活性氧以微妙的调节方式产生，而许多有害的活性氧产生并随机反应。自由基介导的脂质过氧化产物，与酶促氧化产物相反，由非特异性机制产生，引起氧化损伤，但也可能诱导适应性反应，以增强抗氧化酶和化合物的表达。这就提出了一个问题，如果通过补充抗氧化剂来去除太多的ROS可能会扰乱细胞信号通路，实际上会增加慢性疾病的风险。然而，抗氧化剂不太可能损害生理上重要的信号传导途径。
The radical scavenging antioxidants play an essential role in the maintenance of health and prevention of diseases, and a thorough understanding of the action and capacity of antioxidants is critically important. Despite the assumption that antioxidants must exert beneficial effects against oxidative stress, many large-scale randomized controlled trials gave inconsistent and disappointing results on the prevention of chronic diseases. It is now generally accepted that there is no evidence to support the use of non-discriminative antioxidant supplements for prevention of diseases. On the other hand, recent data show that antioxidants may be effective in the prevention and/or treatment of diseases when the right antioxidant is given to the right subject at the right time for the right duration. Now it is accepted that reactive oxygen species (ROS) act as physiologically important signaling messengers as well as deleterious agents. The signaling ROS are produced in a subtly regulated manner, while many deleterious ROS are produced and react randomly. Free radical-mediated lipid peroxidation products which, in contrast to enzymatic oxidation products, are produced by non-specific mechanisms cause oxidative damage, but may also induce adaptive response to enhance the expression of antioxidant enzymes and compounds. This has raised a question if removal of too many ROS by supplementation of antioxidants may upset the cell signaling pathways and actually increase the risk of chronic diseases. However, it is unlikely that antioxidants impair physiologically essential signaling pathways.