Simultaneous quantification of anthraquinone glycosides, aglycones, and glucuronic acid metabolites in rat plasma and tissues after oral administration of raw and steamed rhubarb in blood stasis rats by UHPLC‐MS/MS

Rhubarb is a widely used herbal medicine. To achieve different effects, rhubarb is usually steamed with rice wine (steamed rhubarb). This steaming treatment increases the blood-activating and stasis-removing effects of rhubarb. A specific and accurate ultra high performance liquid chromatography with tandem mass spectrometry method was established for simultaneous determination of anthraquinone glycosides, aglycones, and glucuronic acid metabolites in plasma and tissues after administration of raw rhubarb and steamed rhubarb in blood stasis rats. Chromatographic separation was performed on ACQUITY UPLC BEH Shield RP 18 column using the mobile phase consisting of water and acetonitrile both containing 0.1% formic acid. Satisfactory linearity, precision, accuracy, extraction recovery, and matrix effect have been achieved. From pharmacokinetic study, it showed that glucuronic acid metabolites were found abundantly in plasma as bioactive components. The lower area under concentration-time curve, maximum concentration, and higher apparent volume of distribution (P < 0.01), body clearance (P < 0.01) values in steamed rhubarb showed that most components of steamed rhubarb have lower bioavailability in plasma compared with raw rhubarb. But it found these components were mainly distributed in spleen and liver with large blood flow and perfusion rates. The pharmacokinetics and tissue distribution studies of anthraquinone components will provide helpful information for clinical application of steamed rhubarb and raw rhubarb.