Lee Ki Won, Lee Hyong Joo
Department of Food Science and Technology, School of Agricultural Biotechnology, Seoul National University, Seoul 151-742, Republic of Korea.
Biofactors. 2006;26(2):105-21. doi: 10.1002/biof.5520260202.
Oxidative stress imposed by reactive oxygen species (ROS) plays a crucial role in the pathophysiology associated with neoplasia, atherosclerosis, and neurodegenerative diseases. The ROS-induced development of cancer involves malignant transformation due to altered gene expression through epigenetic mechanisms as well as DNA mutations. Considerable attention has been focused on identifying naturally occurring antioxidative phenolic phytochemicals that are able to decrease ROS levels, but the efficacies of antioxidant therapies have been equivocal at best. Several studies have shown that some antioxidants exhibit prooxidant activity under certain conditions and potential carcinogenicity under others, and that dietary supplementation with large amounts of a single antioxidant may be deleterious to human health. This article reviews the intracellular signaling pathways that respond to oxidative stress and how they are modulated by naturally occurring polyphenols. The possible toxicity and carcinogenicity of polyphenols is also discussed.
活性氧（ROS）引起的氧化应激在与肿瘤形成、动脉粥样硬化和神经退行性疾病相关的病理生理学中起着关键作用。ROS诱导的癌症发展涉及通过表观遗传机制改变基因表达以及DNA突变导致的恶性转化。相当多的注意力集中在鉴定能够降低ROS水平的天然存在的抗氧化酚类植物化学物质上，但抗氧化疗法的效果充其量也只是模棱两可。几项研究表明，一些抗氧化剂在某些条件下表现出促氧化活性，在其他条件下表现出潜在的致癌性，并且大量补充单一抗氧化剂的饮食可能对人类健康有害。本文综述了对氧化应激作出反应的细胞内信号通路以及它们如何被天然存在的多酚调节。还讨论了多酚可能的毒性和致癌性。
