Polyphenols and taste 2 receptors. Physiological, pathophysiological and pharmacological implications

Polyphenols are phytochemical compounds found mostly in plants with several biological properties. Many of the benefits attributed to fruits and vegetables have been linked to their content in these molecules. As a result, the last decade has witnessed an increase in polyphenol-derived compounds claiming diverse therapeutic properties. Although the mechanism of action of such compounds is yet to be fully disclosed, one of the components that recently has been proposed to participate significantly in the health properties of polyphenols is the type 2 taste receptors (T2Rs). These receptors are responsible for the detection of bitter taste and represent the first line of defence against potentially harmful components in food. The recent discovery of extra-oral T2Rs in several metabolically active tissues has generated intense interest in the potential health impact. Given that most phenolic molecules taste bitter, exploring the T2Rs as a putative pharmacological target for the development of plant-based drug therapies is a promising field of research. Some T2Rs are involved in the control of cilia beat frequency and smooth muscle relaxation in the air tract together with leukocyte homeostasis, important events disrupted in the high prevalence of respiratory diseases. Furthermore, T2Rs are involved in nutrient-gut interactions to modulate gut hormones that influence gastrointestinal motility, appetite and glycemia. Thus, this commentary focuses on the latest novelty advances in relation to the peripheral expression of T2Rs, and polyphenols and T2Rs relationship from a therapeutic point of view.