Simultaneous determination of ten alkaloids of crude and wine-processed Rhizoma Coptidis aqueous extracts in rat plasma by UHPLC-ESI-MS/MS and its application to a comparative pharmacokinetic study

Rhizoma coptidis (R.C.), a widely used traditional Chinese medicine, has been used for centuries in the treatment of hypertension, inflammation, dysentery and liver diseases, etc. Wine-processing is a specialized technology by saut ing crude herbal medicine using Chinese rice wine. This paper was designed to establish a simultaneous quantitative method of ten alkaloids (berberine, coptisine, palmatine, jatrorrhizine, epiberberine, magnoflorine, columbamine, noroxyhydrastinine, oxyberberine and 8-oxocoptisine) in rat plasma. Furthermore, the pharmacokinetics of those alkaloids after administration of crude and wine-processed R.C. aqueous extracts was compared. As a result, a ultra high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UHPLC-ESI-MS/MS) method was developed and validated for the first time. Chromatographic separation was achieved on a C-18 column using gradient elution with the mobile phase consisting of acetonitrile and water (containing 0.2% formic acid) at a flow rate of 0.2 ml/min. The validated method showed good linearity over a wide concentration range (r > 0.99), and lower limits of quantification less than 5.46 ng/ml for the each analyte. The intra- and inter-day assay variability was below 9.9% and 10.5% for all analytes, respectively. The extraction recovery of those alkaloids and LS. ranged from 65.3% to 90.7%. The validated method has been successfully applied to pharmacokinetic comparison after administration of crude and wine-processed R.C. aqueous extracts. Pharmacokinetic comparative study showed that C-max of coptisine and 8-oxocoptisine and AUC(0-t) of coptisine, palmatine and 8-oxocoptisine were increased significantly (p <0.05) after wine-processing, while other compounds didn't show significant difference, which suggested that wine-processing exerted limited effects on the absorption of alkaloids. These results might be helpful for R.C.' clinical reasonable application and further studies on its wine-processing mechanism. (C) 2014 Elsevier B.V. All rights reserved.