Pharmacokinetics of paeonol and its metabolites after oral administration of Moutan Cortex in rats / 中草药

ABSTRACT

Objective: To investigate the pharmacokinetics of paeonol and its metabolites M1-M4 in rats after intragastric administration of Moutan Cortex. Methods: SD rats were orally administered different doses (0.5, 1.0, 2.0 g/kg) of Moutan Cortex, and blood was taken from the fundus venous plexus at various time points to collect plasma samples. After given 1.0 g/kg Moutan Cortex extract, urine, bile and feces samples were collected for the corresponding time period. The biological samples were treated with acetonitrile (containing 0.1% formic acid) to precipitate protein, and the established UPLC-MS/MS analysis method was used to detect the content of paeonol and its four metabolites in biological samples. Results: The established biological sample analysis method satisfied the analytical requirements. After administered to rats with doses (0.5, 1.0, 2.0 g/kg) of Moutan Cortex extract, the tmax of paeonol was (0.15 ± 0.08) h, (0.33 ± 0.19) h, (0.31 ± 0.13) h; and t1/2 was (1.16 ± 0.37) h, (1.19 ± 0.45) h, (1.24 ± 0.35) h. Cmax and AUC0-t were increased with the increase of dosage of Moutan Cortex extract, which showed dose-dependent manner. M1-M4 also reached Cmax after 1 h of administration. The main way of excretion of metabolites was confirmed by urine > bile > feces. Conclusion: After ig administration of Moutan Cortex, paeonol has the characteristics of rapid absorption, metabolism and elimination and mainly excreted in the form of metabolites through urine.