Chapter 8 - Plant Polyphenols: Recent Advances in Epidemiological Research and Other Studies on Cancer Prevention

Abstract

Plant polyphenols are considered among the most abundant phytochemicals that are present in human diets, and their regular consumption has been associated with reduced risk of a number of chronic diseases, including cancer, and cardiovascular and neurodegenerative disorders. In the past decades, plant polyphenols have drawn increasing scientific attention due to their potent antioxidant and other properties and their marked effects in the prevention of various oxidative stress-associated diseases. Recently, the polyphenolic extracts from different plants have become a major area of health- and medical-related research. This review provides an update and comprehensive overview of various plant polyphenolic compounds, and the quantification of their antioxidant properties, anticancer activities, and therapeutic effects. Also, the review discusses the current scientific knowledge of various plant polyphenols to inhibit tumorigenesis in animal models and to modulate cell signaling pathways involved in inflammation and the development of malignant tumors, and related biochemical interventions in cell function under both normal and pathological conditions. We present in vitro and in vivo studies (in experimental animals) in which polyphenols showed increased anticancer potential. Also, numerous epidemiological research data and findings from human intervention studies, as well preclinical studies supporting cancer prevention mechanisms. Lastly, we present recent clinical trials for anticancer action of certain polyphenols that showed promising anticancer and therapeutic properties.