Targeting oxidative stress with tea polyphenols: mechanisms and health benefits

Abstract

Oxidative stress occurs when the production of oxidant burden exceeds the body’s ability to counteract it. It is a double-edged sword. On one hand, it damages normal cells and increases the risk of health problems. On the other hand, it can damage cancer cells and bacteria, showing potential in chemotherapy and infection treatment. Tea polyphenols (TP) are the main bioactive compounds in tea leaves. They are usually antioxidants, but become pro-oxidants when auto-oxidized or reacted with reduced transition metal ions. In this review, the role of TP as antioxidants in preventing neurodegenerative diseases, skin photoaging, atherosclerosis, and cigarette smoke-induced pulmonary injury, as well as the role of TP as pro-oxidants in anticancer and antibacterial activities are summarized and elucidated.