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Determination of protein-unbound rhynchiphylline brain distribution by microdialysis and ultra-performance liquid chromatography with tandem mass spectrometry

Authors Lee, Chia-Jung; Hsueh, Thomas Y.; Lin, Lie-Chwen; Tsai, Tung-Hu

Journal BIOMEDICAL CHROMATOGRAPHY , JUN 2014,6:28

DOI 10.1002/bmc.3206 PubMed 24861762

Abstract The stem with hook of Uncaria rhynchophylla (Chinese herbal name Gou-Teng) is a traditional Chinese medicine that has been ethnopharmacologically used to extinguish wind and clean interior heat. Rhynchophylline (RHY), a tetracyclic oxindole alkaloid isolated from U. rhynchophylla, displays significant antineuroinflammatory effects. However, there is no evidence to indicate that rhynchophylline can cross the blood-brain barrier and be detected in the brain. In this study, an in vivo microdialysis sampling method coupled with UPLC/MS/MS was employed for the continuous simultaneous monitoring of unbound RHY in rat blood and brain. The precursor ionproduct ion transition at m/z 385.2160.0 for rhynchophylline was monitored. A calibration curve gave good linearity (r>0.996) over the concentration range from 0.5 to 1000ng/mL. The results demonstrated that rhynchophylline could be detected in the brain and plasma from 15min to 6h after its administration (1 or 10mg/kg, i.v.). All the pharmacokinetic parameters of rhynchophylline in the brain and plasma were obtained. These results show that rhynchophylline can cross the blood-brain barrier and they provide useful clinical information. Copyright (c) 2014 John Wiley & Sons, Ltd.

Species covered 钩藤 Uncaria rhynchophylla