Objective Establishing a fingerprint method to identify the characteristic chemicals in the roots of Gentiana macrophylla and evaluate their quality.Methods RP-HPLC was developed for fingerprint analysis and determination of four ingredients in G macrophylla roots from different sources.LC-ESI-TOF-MS was employed to identify the chromatographic peaks of the fingerprint.Results Five common peaks were identified by comparing their retention time with reference secoiridoid glucosides.Eight major peaks in chromatographic fingerprint were analyzed by on-line LC-ESI-TOF-MS.Four secoiridoid glucosides were identified based on their MS data.Conclusion The method is specific and could be served for the quality identification and comprehensive evaluation of G macrophylla.

An in vitro blood-brain barrier (BBB) model is critical for enabling rapid screening of the BBB permeability of the drugs targeting on the central nervous system. Though many models have been developed, their reproducibility and renewability remain a challenge. Furthermore, drug transport data from many of the models do not correlate well with the data for in vivo BBB drug transport. Induced-pluripotent stem cell (iPSC) technology provides reproducible cell resources for in vitro BBB modeling. Here, we generated a human in vitro BBB model by differentiating the human iPSC (hiPSC) line GM25256 into brain endothelial-type cells. The model displayed BBB characteristics including tight junction proteins (ZO-1, claudin-5, and occludin) and endothelial markers (von Willebrand factor and Ulex), as well as high trans-endothelial electrical resistance (TEER) (1560 Ω.cm ± 230 Ω.cm) and γ-GTPase activity. Co-culture with primary rat astrocytes significantly increased the TEER of the model (2970 Ω.cm to 4185 Ω.cm). RNAseq analysis confirmed the expression of key BBB-related genes in the hiPSC-derived endothelial cells in comparison with primary human brain microvascular endothelial cells, including P-glycoprotein (Pgp) and breast cancer resistant protein (BCRP). Drug transport assays for nine CNS compounds showed that the permeability of non-Pgp/BCRP and Pgp/BCRP substrates across the model was strongly correlated with rodent in situ brain perfusion data for these compounds (R = 0.982 and R = 0.9973, respectively), demonstrating the functionality of the drug transporters in the model. Thus, this model may be used to rapidly screen CNS compounds, to predict the in vivo BBB permeability of these compounds and to study the biology of the BBB.