title: Pharmacokinetics, intestinal absorption and microbial metabolism of single platycodin D in comparison to Platycodi radix extract.
abstract: BACKGROUND
  Platycodi radix, the dried root of Platycodon grandiflorum A. DC, has been widely used as food and herb medicine for treating cough, cold and other respiratory ailments, and platycodin D (PD) is one of the most important compounds in Platycodi Radix.
  
  
  OBJECTIVE
  The purpose of this study was to compare the pharmacokinetic characteristics, intestinal absorption and microbial metabolism of PD in monomer with that in Platycodi radix extract (PRE).
  
  
  METHODS
  In the pharmacokinetic study, the concentrations of PD in rat plasma were determined by ultra-performance liquid chromatography-tandem mass spectrometry and the main pharmacokinetic parameters were calculated by data analysis software (DAS). Besides, in vitro Caco-2 cells and fecal lysate were performed to investigate the intestinal absorption and metabolism, respectively.
  
  
  RESULTS
  The results from pharmacokinetics showed that the area under the curve, the peak concentration the time to reach peak concentration and mean residence time of PD in PRE were enhanced significantly compared with that in single PD. Caco-2 cells transport study indicated that the absorption of PD both in monomer and in PRE were poor owning that the permeability of PD were <1/10(6) cm/s. The hydrolysis degree of PD in PRE was significantly lower than that in monomer PD in fecal lysate, which might be illustrated by the other ingredients in PRE influenced the hydrolysis of PD via gut microbiota.
  
  
  CONCLUSIONS
  These findings indicated that the difference of microbial metabolism, not apparent absorption in intestine for PD between in monomer and in PRE contributed to their pharmacokinetic difference.
authors.affiliation: Jiangsu Key Laboratory of Pediatric Respiratory Disease, Institute of Pediatrics, China ; Jiangsu Engineering Research Center for Efficient Delivery System of TCM, College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China.
authors.forename: Jinjun
authors.initials: J
authors.lastname: Shan
authors.affiliation: Jiangsu Engineering Research Center for Efficient Delivery System of TCM, College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China.
authors.forename: Jiashuang
authors.initials: J
authors.lastname: Zou
authors.affiliation: Jiangsu Key Laboratory of Pediatric Respiratory Disease, Institute of Pediatrics, China.
authors.forename: Tong
authors.initials: T
authors.lastname: Xie
authors.affiliation: Jiangsu Engineering Research Center for Efficient Delivery System of TCM, College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China.
authors.forename: An
authors.initials: A
authors.lastname: Kang
authors.affiliation: Jiangsu Key Laboratory of Pediatric Respiratory Disease, Institute of Pediatrics, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Jiangsu Key Laboratory of Pediatric Respiratory Disease, Institute of Pediatrics, China.
authors.forename: Haishan
authors.initials: H
authors.lastname: Deng
authors.affiliation: Jiangsu Engineering Research Center for Efficient Delivery System of TCM, College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China.
authors.forename: Yancao
authors.initials: Y
authors.lastname: Mao
authors.affiliation: Jiangsu Key Laboratory of Pediatric Respiratory Disease, Institute of Pediatrics, China ; Jiangsu Engineering Research Center for Efficient Delivery System of TCM, College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China.
authors.forename: Liuqing
authors.initials: L
authors.lastname: Di
authors.affiliation: Jiangsu Key Laboratory of Pediatric Respiratory Disease, Institute of Pediatrics, China.
authors.forename: Shouchuan
authors.initials: S
authors.lastname: Wang
keywords: Intestinal absorption; Platycodi radix; microbial metabolism; pharmacokinetics; platycodin D