Metabolites identification of berberine in rats using ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry.

Berberine (BBR), the principle component for many medicinal plants such as Coptis chinensis Franch., Phellodendron chinense Schneid., and Mahonia bealei (Fort.) Carr., possesses diverse pharmacological activities, including anti-bacterial, anti-inflammatory, antitumor, hypolipidemic and antidiabetic activities. In this study, a rapid and reliable method using a five-step strategy based on the ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS), and metabolynx™ software with mass defect filter (MDF) technique was developed to investigate the metabolism of BBR. Plasma, bile, urine and feces samples were collected from rats after oral administration of BBR with a dose of 100mg/kg/day for three consecutive days and analyzed to characterize the metabolic profile of BBR. By comparing the molecular weights and MS fragmentations of the metabolites with those of the parent drug and reference standards, a total of 97 metabolites were identified, including 68 metabolites in urine, 45 metabolites in plasma, 44 metabolites in bile and 41 metabolites in feces. Demethylation, demethylenation, reduction, hydroxylation, and subsequent glucuronidation, sulfation and methylation were the major metabolic pathways of BBR in vivo.