Pharmacokinetic study of six triterpenoids of raw and processed Alisma plantago-aquatica in rat plasma by using ultra performance liquid chromatography-tandem mass spectrometry approach.

Alisma plantago-aquatica is known to regulate water and fluid balance in cells, and is under testing for the therapy for patients suffering from chronic nephritis. Herein, a UHPLC-MS/MS method was established and validated for the determination of six bioactive triterpenoids of raw and salt-processed Alisma plantago-aquatica in rat plasma. The acquired plasma was subjected to protein precipitation with acetonitrile. Glycyrrhetinic acid was employed as internal standard. The pretreated samples were separated on a reversed phased column with a mobile phase of acetonitrile and water (including 0.1% formic acid). The MRM mode for the six triterpenoids were at m/z 535.4 → 489.4 for alisol A, m/z 517.3 → 471.4 for alisol B, m/z 533.3 → 487.3 for alisol F, m/z 577.4 → 531.4 for alisol A-24-acetate, m/z 559.4 → 495.4 for alisol B-23-acetate, m/z 573.3 → 509.3 for alisol C-23-acetate, and 469.3 → 425.3 for the IS. The accuracy and precision of the method were determined as -2.2%-3.6% and 0.8%-3.0%, respectively. This approach was employed to a pharmacokinetic study of the six bioactive triterpenoids after intragastric administration of raw and processed Alisma plantago-aquatica in rats. The two-phasic pharmacokinetic of alisol B, alisol C-23-acetate and alisol F were reported for the first time, which may be ascribed to enterohepatic recirculation of these triterpenoids.