title: Transport behavior and efflux of Rg1 in rat pulmonary epithelial cells.
abstract: The aim of this study was to investigate whether ginsenoside Rg1 could be transported into rat pulmonary epithelial cells and its transport behavior and efflux through the cells. A high-performance liquid chromatography coupled with 2487 UV-vis detector at 203 nm was applied. The mobile phase was 0.05% phosphate-acetonitrile (75:25, v/v). Cells were incubated with Rg1 (100 microg/mL) for a specific time, then lysed and sonicated in methanol to extract intracellular Rg1. Cells incubated with Rg1 and verapamil or KCN were processed by the same method. A 20 microL aliquot of sample was injected into the HPLC system to determine Rg1 concentration. The results showed that Rg1 could be transported into the epithelial cells with peak concentration of 1.28 microg/10(5) cells at 0.5 h. Metabolic inhibitor KCN and P-glycoprotein inhibitor verapamil could increase Rg1 concentration within the cells, indicating that efflux of Rg1 was energy-dependent and P-gp was likely to be involved. This is the first time that the transport behavior and efflux of Rg1 through rat pulmonary epithelial cells has been demonstrated. The phenomenon that Rg1 concentration in the cells decreased whereas that in the medium remained high indicated that a more effective means of drug administration should be found.
authors.affiliation: Protein Science Laboratory of Ministry of Education, Laboratory of Pharmaceutical Sciences, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084, People's Republic of China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Meng
authors.forename: Hongyin
authors.initials: H
authors.lastname: Zhang
authors.forename: Yunan
authors.initials: Y
authors.lastname: Zhao
authors.forename: Jiaqi
authors.initials: J
authors.lastname: Lan
authors.forename: Lijun
authors.initials: L
authors.lastname: Du
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002463:Cell Membrane Permeability / Q000187:drug effects; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D004847:Epithelial Cells / Q000378:metabolism*; D036145:Ginsenosides / Q000008:administration & dosage / Q000378:metabolism / Q000493:pharmacokinetics*; D008168:Lung / Q000166:cytology / Q000378:metabolism*; D008297:Male; D015394:Molecular Structure; D051381:Rats; D014700:Verapamil / Q000494:pharmacology
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D036145:Ginsenosides; D014700:Verapamil; C035054:ginsenoside Rg1