Comparative pharmacokinetic study of the components in Alpinia oxyphylla Miq.-Schisandra chinensis (Turcz.) Baill. herb pair and its single herb between normal and Alzheimer’s disease rats by UPLC-MS/MS

Abstract Alzheimer's disease (AD) is a neurodegenerative disease that seriously affects daily life. Schisandra chinensis (Turcz.) Baill. Fructus (SCF) and Alpinia oxyphylla Miq. Fructus (AOF) have been regarded as classical herbs for dementia since ancient times. Alpinia oxyphylla Miq.—Schisandra chinensis (Turcz.) Baill. herb pair (ASHP) is the compatible form of the two herbs. Ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was established for the simultaneous determination of protocatechuic acid, chrysin, schisandrin, gomisin A, gomisin B, nootkatone, deoxyschizandrin, schisandrin B and schisandrin C in rat plasma. The pharmacokinetic differences of the above nine active components in normal rats and AD model rats after oral administration of SCF, AOF, and ASHP ethanol extracts were investigated. Chloramphenicol and bifendate were used as the internal standards. Extraction of plasma sample was by liquid–liquid extraction with ethyl acetate. A SBC18 column (2.1 mm × 100 mm, 1.8 μm) was used in this experiment at a flow rate of 0.3 mL/min at 30 °C with linear gradient elution using acetonitrile and water containing 0.1% formic acid. This study showed ASHP can improve the absorption of protocatechuic acid, chrysin, schisandrin, gomisin B, nootkatone, deoxyschizandrin, schisandrin B and schisandrin C in vivo and slow down part of these components’ elimination. In addition, compared with normal rats, the pharmacokinetic parameters changed significantly in AD model rats’ plasma after oral administration of ASHP. Hence, these may be the pharmacokinetic mechanism of ASHP, in addition to serving as a potential agent in the treatment of AD.