Plant Polyphenols as Antioxidants Influencing the Human Health

Widely distributed in plant kingdom and abundant in our diet plant polyphenols are today among the most talked about concerning the classes of phytochemicals. There are several thousand plant-derived compounds of biogical interest that have more than one phenolic hydroxyl group attached to one or more benzene rings, thus qualifying as polyphenols. In recent years, polyphenols have gained a lot of importance because of their potential use as prophylactic and therapeutic agents in many diseases, and much work has been presented by the scientific community which focuses on their antioxidant effects. Traditionally, herbal medicines with antioxidant properties have been used for various purposes and epidemiological data also point at widespread acceptance and use of these agents. Plant polyphenols have been studied with intention to find compounds protecting against a number of diseases related to oxidative stress and free radical-induced damage, such as cardiovascular and neurodegenerative diseases, cancer, diabetes, autoimmune disorders and some inflammatory diseases. In order to evaluate the efficacy of polyphenols as antioxidants as well as to elucidate the mode of their action, researchers today are using a wide range of experimental models, from the simplest chemical antioxidant assays through the biologically more relevant cellular-based assays to the most accurate animal models, and ultimately clinical studies in humans. The latest scientific knowledge offers a more detailed understanding of the biological effects of polyphenols and their role in human health promotion and disease prevention.