Consistency evaluation of Chaihuang granules based on pharmacokinetics and metabolomics

Consistency evaluation of Traditional Chinese Medicinal preparations (TCMPs) with complex chemical composition is challenging. Chaihuang granules (CHG), as a well-known TCMP, consists of Chaihu (Bupleuri Radix) and Huangqin (Scutellariae Radix) extract. In this work, we used pharmacokinetics and metabolomics to evaluate consistency of CHG products from two different manufacturers. In the pharmacokinetic study, a liquid chromatography tandem mass spectrometry (LC-MS/MS) method was applied to determine the plasma concentration-time profiles of baicalin in rat plasma. Pharmacokinetic parameters, including the maximum concentration in blood (C_max), area under the curve (AUC), the time to reach C_max (T_max), and half-life (T_1/2), were calculated to assess the consistency preliminarily. And there was no significant difference in these pharmacokinetic parameters between the two CHG. In LC-MS-based metabolomics, the metabolic response profiles changes based on relative distance values (RDV) to different CHG products were compared. Meanwhile, the kinetic process of 31 differential endogenous metabolites that altered by CHG were determined. Metabolomics data showed the similar metabolic regulation effects to rats of the two formulations. Both pharmacokinetic and metabolomics results indicated there was no significant difference between CHG products. Furthermore, metabolic pathways significantly altered by CHG were elucidated, including phenylalanine, tyrosine and tryptophan biosynthesis, valine, leucine and isoleucine biosynthesis, phenylalanine metabolism, and sphingolipid metabolism. Pharmacokinetics combined with metabolomics could provide a comprehensive perspective for consistency evaluation of CHG.