Traditional Chinese Bitter Flavor theory: Is there any relation with taste type II receptors?

Introduction: As a guiding principle, traditional Chinese medicine (TCM) theories study the formation, mechanism and the regularity of application of Chinese herbs. This is limited by the understanding of the natural properties of the herbs at the cognitive level. As an important part of TCM theories the Five Flavor theory describes the function of drugs with five tasting adjectives: bitter, sweet, pungent, sour and salty. Methods: In this study, we present the hypotheses that Bitter Flavor theory has instructive significance on account of its relationship with bitter taste receptors (taste receptors, type 2, also known as T2Rs). Due to the lack of crystallized structure of T2Rs, in silico modeling method allows us to visualize the relationship between compounds from TCM showing Bitter Flavor property and T2Rs. In this study, pharmacophore models of T2R1, T2R10, T2R14 and T2R46 have been generated to screen agonists from TCM showing Bitter Flavor properties. Results: According to the simulation results, 71.84% agonists of T2Rs were derived from medicinal herbs showing Bitter Flavor properties and the experimental evidence of the hits through virtual screening was validated via literature mining. Conclusion: The methods used in this research on bitter taste receptors supports the assumptions underpinning the traditional Chinese Bitter Flavor theory and provides a way to explore the potential science behind the Five Flavors theory of TCM which could be extended to explore other similar problems in TCM theory. (C) 2016 Published by Elsevier GmbH.