RATIONALE: Luteolin-7-O-glucoside (L7G), the main bioactive ingredient of Chinese Lantern, has various biological functions, including anti-inflammatory and anti-oxidative activities. However, research on luteolin-7-O-glucoside has focused on the extraction, separation and biological activities of this natural product, whereas the metabolism of luteolin-7-O-glucoside in vivo is not fully understood. In order to explore the metabolic profile of luteolin-7-Oglucoside, we investigated its metabolites in plasma, bile, urine and feces samples following oral administration to rats. METHODS: In this study, an ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/QTOFMS) method with a workflow-interpretation strategy was developed to profile and identify the major metabolites of luteolin-7-O-glucoside in rat urine, plasma, bile and feces after oral administration. RESULTS: A total of 44 luteolin-7-O-glucoside-related metabolites were identified in rat biological samples after oral administration of luteolin-7-O-glucoside, including 35 metabolites in urine, 17 metabolites in plasma, 17 metabolites in bile and 5 metabolites in feces. Additionally, three major metabolites (M22, M40 and M44) were isolated as standards from urine and feces. CONCLUSIONS: The study indicated that luteolin-7-O-glucoside was hydrolyzed to luteolin firstly, and then for further absorption, metabolism and excretion in vivo. The results showed that phase I metabolites are hydrolysis and reduction metabolites, and phase II metabolites include sulfation, glucuronidation and methylation metabolites. This research provides scientific and reliable support for full understanding of the metabolic profiling of luteolin-7-O-glucoside and the results provide evidence that should help to elucidate the effective substance basis of luteolin-7-O-glucoside in vivo.

The calyces of Physalis alkekengi var. franchetii (Chinese Lantern, JDL) are well-known as traditional Chinese medicine owing to its various therapeutic effects. However, the bioactive constituents responsible for the pharmacological effects of JDL and their metabolites in vivo are still unclear to date. In this paper, an ultra-high-pressure liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC/Q-TOF-MS/MS) method was established to identify absorbed constituents and in vivo metabolites in rat biological fluids after oral administration of JDL. Based on the proposed strategy, 33 compounds were observed in dosed rat biosamples. Twelve of 33 compounds were indicated as prototype components of JDL, and 21 compounds were predicted to be metabolites of JDL. Finally, the metabolic pathways were proposed, which were glucuronidation, sulfation, methylation and dehydroxylation for flavonoid constituents and sulfonation and hydroxylation for physalin consitituents. This is the first systematic study on the absorbed constituents and metabolic profiling of JDL and will provide a useful template for screening and characterizing the ingredients and metabolites of traditional Chinese medicine.