title: [Study on transport mechanism of baicalin in Scutellariae radix extracts and effect of Angelica dahurica extracts on transport of baicalin by Caco-2 cell monolayer model].
abstract: OBJECTIVE
  To study the transport mechanism of baicalin of Scutellariae Radix extracts and the effect of Angelica dahurica extracts on the intestinal absorption of baicalin by using Caco-2 cell monolayer model, in order to analyze the effect mechanism of Angelica dahurica extracts on the intestinal absorption of baicalin.
  
  
  METHODS
  The Caco-2 cell monolayer model was established with human colonic adenocarcinoma cells, and used to study the effect of pH, time, drug concentration and temperature on the transport of baicalin in Scutellariae Radix extracts, the effect of P-gp and MRP protein-dedicated inhibitors on the bidirectional transport of baicalin in Caco-2 cell model, and the effect of angelica root extracts on baicalin absorption and transport.
  
  
  RESULTS
  Baicalin was absorbed well at 37 degrees C and under pH 7.4 condition and concentration dependent. Its proteins became inactive at 4 degrees C, with a low transport. The bi-drectional transfer PDR was 0. 54. After P-gp inhibitor verapamil and MRP inhibitor probenecid were added, the value of PappBL-AP of baicalin decreased, but without any difference in PDR. The transport of baicalin was improved by 2.34, 3.31 and 3.13 times, after A. dahurica extract coumarin, volatile oil, and mixture of coumarin and volatile oil.
  
  
  CONCLUSIONS
  The transport mechanism of baicalin is mainly passive transfer and supplemented with efflux proteins involved. A. dahurica extracts can enhance the absorption of baicalin, which may be related to the passive transfer merchanism of baicalin. A. dahurica extracts' effect in opening the close junction among cells may be related to its expression or function in inhibiting efflux proteins.
authors.affiliation: Key Laboratory of Modern Preparation of Traditional Chinese Medicine under Ministry of Education, Jiangxi University of Traditional Chinese Medicine, Nanchang 330004, China. paln7@163.com
authors.forename: Xin-Li
authors.initials: XL
authors.lastname: Liang
authors.forename: Meng-Liang
authors.initials: ML
authors.lastname: Zhu
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Zhao
authors.forename: Guo-Wei
authors.initials: GW
authors.lastname: Zhao
authors.forename: Zheng-Gen
authors.initials: ZG
authors.lastname: Liao
authors.forename: Yun-Chao
authors.initials: YC
authors.lastname: Cao
authors.forename: Ming
authors.initials: M
authors.lastname: Yang
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D029969:Angelica / Q000737:chemistry*; D001692:Biological Transport / Q000187:drug effects; D018938:Caco-2 Cells; D045744:Cell Line, Tumor; D003374:Coumarins / Q000737:chemistry / Q000494:pharmacology; D004347:Drug Interactions; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000494:pharmacology; D005419:Flavonoids / Q000493:pharmacokinetics*; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects / Q000502:physiology; D009822:Oils, Volatile / Q000737:chemistry / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018517:Plant Roots / Q000737:chemistry; D011339:Probenecid / Q000494:pharmacology; D031364:Scutellaria baicalensis / Q000737:chemistry*; D014700:Verapamil / Q000494:pharmacology
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D003374:Coumarins; D004365:Drugs, Chinese Herbal; D005419:Flavonoids; D009822:Oils, Volatile; D010936:Plant Extracts; C038044:baicalin; C030123:coumarin; D014700:Verapamil; D011339:Probenecid