2017 Volume 70 Issue 5 Pages 213-223
Polyphenols have multiple functions for prevention of various diseases, including those related to lifestyle. It is known that polyphenols possess strong antioxidant activity, which contributes to prevention of certain diseases. However, polyphenols also have the ability to modulate metabolism through mechanisms that are separate from their antioxidant activity. In this review, we discuss the mechanism by which flavonoids modulate drug-metabolizing enzymes and help to prevent obesity and hyperglycemia. In the former process, the aryl hydrocarbon receptor (AhR) is a key molecule. The mechanism by which suppression of AhR transformation is dependent on the sub-class structure of flavonoids: flavones and flavonols act as AhR antagonists, indicating that they have the potential to prevent AhR agonist-induced carcinogenesis. In the latter process, AMP-activated protein kinase (AMPK) and glucose transporter 4 (GLUT4) are key molecules related to obesity and hyperglycemia, respectively. AMPK is known to act as an energy sensor for the whole body. In muscle cells, activation of AMPK promotes translocation of GLUT4, indicating that both AMPK and GLUT4 play a pivotal role in prevention of hyperglycemia. We show that polyphenols activate AMPK in various tissues and promote GLUT4 translocation in skeletal muscle.
