Metabolite identification and pharmacokinetic study of Lamiophlomis rotata in rats†
An ultra-high performance liquid chromatography coupled with time-of-flight mass spectrometry technique and a subsequent LC-MS/MS method were developed for metabolite profile study of Lamiophlomis rotata extract after its oral administration. Metabolite profile analysis for plasma, bile, urine and feces were performed on a sub-2-μm analytical column, and showed that 39 prototypes and 47 metabolites were identified or tentatively characterized. More than half the metabolites underwent phase II reaction, including sulfate, glucuronide, taurine, glycine, and glutathione conjugation. The targeted and valid LC-MS/MS method, using one-step protein precipitation for rat plasma, was applied for the pharmacokinetic study of shanzhiside methyl ester, 8-O-acetylshanzhiside methyl ester, lamalbid, verbascoside, forsythoside B, and luteolin-7-O-β-D-glucopyranoside. Pharmacokinetics results showed that six bioactive components did not vary significantly in rats after administration of the aerial parts and the whole plant, which was consistent with the metabolite profile comparison between two groups. This article contributes to the understanding of the metabolism of L. rotata, and provides detailed performance analysis and scientific data to support the medicine parts alteration in the Chinese Pharmacopoeia.