Identification and characterization of chemical constituents in Mahuang Guizhi Decoction and their metabolites in rat plasma and brain by UPLC-Q-TOF/MS

Objective: Mahuang Guizhi Decoction (MGD), an essential herbal pair in traditional Chinese medicine, is able to release cold, fever and asthma, mainly containing alkaloids, flavonoids, phenylpropanoids and amino acids. However, the absorption and distribution of these four category compounds in vivo still remained unclearly. Methods: In our research, we utilized UPLC-Q-TOF-MS technique to identify the constituents within MGD, as well as the prototypes of MGD and their metabolites absorbed in plasma and brain. We further profiled the drug-time curve of prototypes and metabolites of MGD both in plasma and brain. Results: Our results showed that 105 constituents were characterized in MGD. Thirty of them could be absorbed into blood, and ten of them could be distributed into brain. We also discovered eight new bio-transformed metabolites in blood, and a half of which could pass through the blood-brain barrier. In addition, all components detected in vivo could be absorbed and distributed immediately. Conclusion: These findings provide an approachable method to analyze the potential bio-active compounds in MGD and their in vivo behaviors, which could promote the efficacious material basis study of MGD and the security of clinical utilization. (c) 2024 Tianjin Press of Chinese Herbal Medicines. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).