Dear Colleagues,

Polyphenols are a complex group of phytochemicals that have ubiquitous distribution in plants, some fungi and even some micro-organisms. Most are best known for their potent antioxidant potential, however this is only one of a plethora of activities that have been associated with polyphenols. Some have hormone-like activity, behaving as estrogens or estrogen antagonists (e.g. phytoestrogens), others are protein kinase inhibitors, anti-inflammatory agents, antimicrobials, anti-fungals, and even insect repellants or attractants. Others control cell cycle progression, cellular differentiation, senescence and apoptosis. They may modulate enzymes associated with eicosanoid metabolism and thereby affect cell signaling, lipid peroxidation, and DNA-damage. Some polyphenols are excellent chelating agents and can interfere with metal induced oxidative damage. As well as being antioxidants themselves, several polyphenols, particularly the flavonoids, have been shown to modulate the expression of endogenous antioxidant molecules and proteins such as glutathione, glutathione peroxidase, superoxide dismutase and catalase. Because of their wide-ranging activities, polyphenols are aggressively being studies for their activities as human and animal health promotion agents and effective disease preventive or treatment agents for a number of human ailments including: Alzheimer’s disease, cancer, atherosclerosis and other cardiovascular diseases, multiple sclerosis, and autoimmune disorders. Major issues continue to be identifying the “active metabolites” and their mechanisms of action as well as determining the barriers to bioavailability of polyphenols from foods, herbs and extracts, and determining the “recommended” levels that should be being consumed by humans for optimal health.

Prof. Dr. Kelly Meckling
Guest Editor