OBJECTIVE To identify and analyze the constituents in rat serum after oral administration of Shegan Mahuang Decoction, and to provide a reference for its further research on pharmacodynamics material basis.

METHODS Male SD rats were used as experimental subjects and were administered the decoction of Shegan Mahuang Decoction at a dose of 18.9 g·kg^-1 for 7 consecutive days. Two hours after the last administration, blood was collected from the abdominal aorta to obtain serum samples. Ultra-performance liquid chromatography-quadrupole-electrostatic field orbitrap mass spectrometry (UPLC-Q-Exactive Orbitrap-MS) was employed to analyze the serum of rats in both the blank control group and the administration group. Based on the retention time, accurate relative molecular weight, molecular fragment ion peaks provided by mass spectrometry, reference substance information, and relevant literature, the blood-entering components of Shegan Mahuang Decoction in the rats after gavage administration were identified.

RESULTS A total of 30 components were identified, including 8 flavonoids, 7 phenolic acids, 3 alkaloids, 4 glycosides, 1 saponins, 2 lignans, 3 terpenoids and other compound components.

CONCLUSION The thirty components absorbed into blood may be the potential bioactive components in Shegan Mahuang Decoction, providing a scientific basis for clarifying its material basis in pharmacodynamics.