Affiliations: Department of Food Science and Technology, School of
Agricultural Biotechnology, and Center for Agricultural Biomaterials, Seoul
National University, Seoul 151-742, Republic of Korea
Note: [] Address for correspondence: Hyong Joo Lee, PhD, Department of
Food Science and Technology, Shillim-dong, Gwanak-gu, Seoul 151-742, Republic
of Korea. Tel.: +82 2 880 4853; Fax: +82 2 873 5095; E-mail: leehyjo@snu.ac.kr
Abstract: 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.
