UPLC-Q-Exactive-based rats serum metabolomics for characterization of traditional Chinese medicine Natures and Flavors

Ethnopharmacology relevant: Four Natures and five Flavors comes from the high generalization of medicine pharmacological rules from clinical practice by ancients. Flavor and Naturesare both descriptions of the effect properties of traditional Chinese medicine. At present, researchers have realized that the Flavors (Pungent, Sour, Sweet, Bitter and Salty) are related to the different pharmacological effects of treatment. The Natures (Warm, Hot, Cold and Cool) are closely related to energy and substance metabolism and contribute to the effect of the Flavors. Since Four Natures and five Flavors are the rules derived from clinical practice, how to describe and characterize Natures and Flavors scientifically is still a problem that needs to be solved. Aim of the study: the aim is to objectively further understand the scientific connotations of properties (Fla-vorsand Natures) from the perspective of metabolomics and characterize them by metabolites. Materials and method: Pungent-Neutral, Sweet-Neutral and Bitter-Neutral TCMs were selected to charac-terize the Flavors (Pungent, Sweet and Bitter). Pungent-Warm and Bitter-Cold were selected to characterize the Natures (Warm and Cold). The rat serum metabolomics was performed on UHPLC-Q-Exactive. Metabolites were identified through the metabolites databases and related literature.Results: The Flavors and Natures metabolites were identified, respectively, including four Pungent, four Sweet and thirteen Bitter characterized metabolites and thirteen Cold and sixteen Warmrelated metabolites. Conclusions: The Natures characterized metabolites show the Natures are closely related to lipid and energy metabolism. The Warm may promote lipid metabolism to produce ATP to generate energy through bile acid metabolism and purine metabolism. The Cold may inhibit lipid metabolism to generate ATP to decrease energy through the way of tryptophan metabolism and purine metabolism. The Flavors characteristic metabolites can provide a theoretical basis for the rules of the Flavors. These metabolites can also be used to characterize TCM's Natures and Flavors in the development of traditional Chinese medicine resources and quality control.

Automated summary

This study aims to objectively understand the scientific connotations of the properties (Flavors and Natures) of traditional Chinese medicine from the perspective of metabolomics and characterize them by metabolites. The results show that the characterized metabolites of Natures are closely related to lipid and energy metabolism. Warm stimulates lipid metabolism to produce energy, while Cold inhibits lipid metabolism to decrease energy. The characterized metabolites of Flavors can provide a theoretical basis for the rules of Flavors and can be used in the development and quality control of traditional Chinese medicine resources.