Systematically characterize the absorbed effective substances of Wutou Decoction and their metabolic pathways in rat plasma using UHPLC-Q-TOF-MS combined with a target network pharmacological analysis

Wu-tou Decoction (WTD) is a famous traditional Chinese medicine (TCM) formula which is applied to treat arthritis and pain of joints. In this study, a sensitive and rapid method was developed for the separation and identification of the absorbed constituents and metabolites of WTD in the rats plasma by ultra high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS). A total of 22 absorbed prototype constituents and 49 metabolites were identified or tentatively characterized in dosed plasma. The possible metabolic pathways of these constituents involved sulfation, glucuronidation, demethylation, hydroxylation and so on. What's more, we optimized the conventional process ways of network pharmacology and proposed a new concept called target-network pharmacology (T-NP). T-NP method used the absorbed constituents and the corresponding target proteins to generate compound-target network, and compare to the conventional method indifferent using the compounds collected from herbs, it could reduce the false positive results. We found that the following proteins were related to the WTD therapeutic effects, such as PTGS2, PTGS1, MAPK3, PPARG, TNF, IL4 and IL6. On the whole, the proposed method clearly presented the metabolic processes of WTD and the results gave a comprehensive metabolic profile of WTD in vivo for the first time. The combining use of the T-NP method could discover potential drug targets and disclose the biological processes of WTD, which will open up a new approach in the study of TCM in future. (C) 2017 Elsevier B.V. All rights reserved.