Determination of acteoside in Cistanche deserticola and Boschniakia rossica and its pharmacokinetics in freely-moving rats using LC–MS/MS

A sensitive LC–MS/MS method with a simple solid-phase extraction for the determination of acteoside in rat plasma and tissue homogenates was established for the investigation of bioavailability and brain distribution in freely-moving rats. Acteoside in Cistanche deserticola and Boschniakia rossica was also determined. Acteoside and internal standard were separated on a RP-select B column (125 mm × 4.6 mm i.d., particle size 5 μm). The mobile phase consisted of 35% methanol and 65% acetic acid–water (1:100, v/v) at a flow-rate of 1 mL/min. Acteoside and the internal standard were monitored using the multiple-reaction monitoring (MRM) mode at m/z transitions of 623 → 161 and 609 → 301, respectively. The acteoside content was 38.4 ± 2.4 mg/kg (n = 3) for B. rossica, which is obviously lower than 21134.2 ± 805.5 mg/kg (n = 3) of C. deserticola. The protein binding in rat plasma was 75.5 ± 1.8%. The brain distribution result indicated that acteoside was evenly distributed in brain tissues (brain stem, cerebellum, the rest of the brain, cortex, hippocampus and striatum) which was about 0.45–0.68% of that in plasma (4.5 ± 0.5 μg/mL) after 15 min of acteoside administration (10 mg/kg, i.v.). After acteoside was given (3 mg/kg, i.v.; 100 mg/kg, p.o.), the oral bioavailability (AUCp.o./dosep.o.)/(AUCi.v./dosei.v.) was only 0.12%.