Metabolic profiling of luteolin‐7‐O‐glucoside in rat urine, plasma, bile and feces after oral administration using ultra‐high‐performance liquid chromatography/quadrupole time‐of‐flight mass spectrometry

Abstract

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.

Rapid characterization of the absorbed chemical constituents of Tangzhiqing formula following oral administration using UHPLC–Q‐TOF‐MS

“…Compounds P10, P14, P16, P18, P23, P32, P33, P39, and P41 were confirmed by authentic standards and identified as hyperoside, rutin, isoquercitrin, astragalin, luteoloside, quercetin, luteolin, kaempferol, and isorhamnetin. And flavonoid glycosides were characterized according to form the prominent ion of [M+H‐162] + or [M+H‐146] + in their MS 2 spectra, indicating loss of glucose or rhamnose residue .…”

“…In other words, it was necessary to detect the chemical constituents and metabolites so as to clarify the effective ingredients and the possible metabolic pathways of TZQ-F in vivo. In addition, the in vivo components of the two major herbs (Lotus leaf and Mulberry leaf) were also investigated in previous studies, and 15 and 36 metabolites were identified, respectively [7,8]. These experiences were helpful for this experiment.…”

“…Compounds P10, P14, P16, P18, P23, P32, P33, P39, and P41 were confirmed by authentic standards and identified as hyperoside, rutin, isoquercitrin, astragalin, luteoloside, quercetin, luteolin, kaempferol, and isorhamnetin. And flavonoid glycosides were characterized according to form the prominent ion of [M+H-162] + or [M+H-146] + in their MS 2 spectra, indicating loss of glucose or rhamnose residue [11][12][13][14][15][16][17][18]. A total of 27 flavonoid-related metabolites were detected in rat plasma, urine, and feces; and they chiefly originated from kaempferol, luteolin, isorhamnetin, quercetin, and apigenin.…”

“…Because the flavonoids contained multiple phenolic hydroxyl groups, there were more than one active site. Moreover, the fragment ion of [M+H-176-176] + was discovered in the MS 2 spectra, suggesting the metabolites connected the two glucuronic acid moieties [14][15][16][17][18][19][20]. In addition, M46 showed the protonated molecule at m/z 301.0715 and deprotonated ion at m/z 299.0556, which yielded characteristic fragment ions at m/z 286.0488 and 284.0320 (loss of a CH 3 ).…”

Identification of metabolites of palmatine in rats after oral administration using ultra‐high‐performance liquid chromatography/quadrupole time‐of‐flight mass spectrometry

“…UPLC operates with 1.7 μm chromatographic particles and a fluid system capable of operating at pressures in the 6000–15000 psi range, which could provide better peak resolution and higher sensitivity and speed for complex mixture separation compared with conventional high‐performance liquid chromatography (HPLC) . In general, the UPLC technique is combined with high‐resolution mass spectrometry (HRMS) for metabolite identification in vitro or in vivo . Quadrupole time‐of‐flight mass spectrometry (QTOF‐MS), a HRMS technique, allows the generation of mass information with higher accuracy and precision for the identification of known or unknown compounds, which could provide candidate empirical formulae with a mass error of less than 5 ppm .…”