ABSTRACT
Xiaokeyinshui extract combination (XEC), originating from a traditional Chinese formula Xiaokeyinshui (XKYS) recorded in ancient Bencao, has been reported to exert significant hypoglycemic effects. However, the chemical profiles, metabolic transformation and pharmacokinetic behavior of XEC in vivo were unclear. The research was to investigate the chemical constituents, metabolic profiles and pharmacokinetic behavior of XEC. A UPLC-QE-Orbitrap-HRMS qualification method was developed to identify the chemical constituents in XEC and xenobiotics of XEC in plasma, urine, feces and bile of rats after oral administration. A LC-MS quantification method was established and applied for the pharmacokinetic studies of major active compounds of XEC in normal and T2DM rats and Coptidis Rhizoma extracts (CRE) in T2DM rats. Fifty eight compounds in XEC and a total of 152 xenobiotics were identified in T2DM rats, including 28 prototypes and 124 metabolites. The metabolic pathways were demethylation, demethyleneization, reduction, hydroxylation, hydrolysis and subsequent binding reactions, including glucuronidation, sulfation and methylation. According to the results of chemical constituents and metabolites, 7 ingredients, including berberine, palmatine, coptisine, epiberberine, berberrubine, magnoflorine and aurantio-obtusin were suggested for markers to comparative pharmacokinetics study in normal rats and T2DM rats. Compared with normal rats, the Tmax of berberine, palmatine, coptisine, epiberberine, berberrubine and magnoflorine was significantly longer. The value of Cmax for palmatine, coptisine, epiberberine and berberrubine was significantly decreased in XEC T2DM group. The value of AUC for alkaloids was higher in diabetic rats. After oral CRE, alkaloids including berberine, palmatine, coptisine, epiberberine, berberrubine and magnoflorine could be detected in vivo. Compared with T2DM rats after oral administration of CRE, the value of Tmax and Cmax for berberine, palmatine, coptisine, epiberberine, berberrubine and magnoflorine exhibited significant differences in XEC T2DM group. This research provided an overview of the chemical profiles and metabolic profiling of XEC and elucidated the effect of diabetic state and compatibility on pharmacokinetic behaviors of active components in XEC. This research also can provide the material basis of XEC for subsequent quality control research.