Fangji Huangqi Decoction

Traditional Chinese medicine (TCM) is characterized by its multiple components. The utilization of mathematical statistical methods to integrate the pharmacokinetics of monomer components can provide a comprehensive understanding of the holistic pharmacokinetic process of TCM. Two distinct integrated methods, namely the correlation coefficient method and the AUC-based weight coefficient method, were employed in this study to elucidate and compare their differences in the integrated pharmacokinetic research of Fangji Huangqi decoction (FHD). FHD is commonly used in clinical practice to treat the nephrotic syndrome. Firstly, one-dose FHD was given to doxorubicin-induced nephropathy (DN) rats, and the prototype compounds of FHD and their metabolites in plasma were qualitatively and semi-quantitatively analyzed by UHPLC-MS/MS. Secondly, the efficacy of FHD was quantitatively characterized by the relative distance method based on metabolomics. The correlation coefficients were obtained by analyzing the correlation between efficacy (relative distance values) and the content of compound, and they were subsequently used for the model integration (correlation coefficient method). Thirdly, the effective compounds of FHD treating DN were screened by integrating network pharmacology and molecular docking, and they were used for another integrated pharmacokinetic model by AUD-based weight coefficient method. Finally, the 2 integrated methods and the 2 integrated pharmacokinetic models were compared. In this study, 30 prototype compounds and 41 metabolites of FHD in plasma were identified, and the pharmacokinetic curve of 18 prototype compounds were built. The efficacy of FHD in the treatment of DN has been relatively quantitation. The 2 established integrated pharmacokinetic models of FHD indicated that the correlation coefficient method was the optimal approach for conducting the integrated pharmacokinetic research on the TCM with unknown effective compounds, whereas the AUC-based coefficient method was suitable for the TCM with the clear effective compounds. The integrated pharmacokinetic models indicated that FHD had high bioavailability and an absorption peak at about 6 h after administration, indicating that the 6 h after administration was the critical period of FHD treating DN. This research would be helpful for the pharmacological and pharmacokinetic research of FHD, and provide a method reference for the integrated pharmacokinetic research of TCM.

Fangji Huangqi Tang (FHT), has been reported to show effects on nephrotic syndrome, but its mechanism of action and bioactive components have not yet been determined. In this study, a method using UPLC–HRMS/MS was established for the detection and identification of the chemical constituents and metabolites absorbed into the blood. Absorbed components in serum were then used for the network pharmacology analysis to deduce the mechanism and effective components. A total of 86 compounds were identified or tentatively characterized. Based on the same instrumental conditions, 85 compounds were found in rat serum after oral administration of FHT, including 22 prototypes and 63 metabolites. Network pharmacology analysis showed that absorbed components, such as (3R)‐2′,3′,4′,7‐tetrahydroxyisoflavan, astrapterocarpan, cycloastragenol, 7,2′‐dihydroxy‐3′,4′‐dimethoxyisoflavan, astragaloside IV, astrapterocarpan glucoside and glycyrrhetinic acid, could be responsible for the pharmacological activity of nephrotic syndrome by regulating the VEGF signaling pathway, focal adhesion and MAPK signaling pathway. Furthermore, the pathway‐target network showed that the MAPK1, AKT2 and CDC42 were involved in the signal pathways above. This study provides a scientific basis for the mechanism and effective ingredients of FHT.