title: [Studies on influence factors of gnsenoside Rg1 and Rb1 absorption in intestines of rats].
abstract: OBJECTIVE
  To investigate the absorption of gnsenoside Rg1 and Rb1 in Radix Gngseng at different intestine segments of rats and the influence of the drug solution concentration, pH, P-gp inhibitor.
  
  
  METHODS
  The intestine cannulation was performed for in situ recirculation. Gnsenoside Rg1, Rb1 and phenol red concentration in the flux were separately measured by the reversed phase HPLC and UV.
  
  
  RESULTS
  When the concentration was raised from 0.075-0.75 g L(-1) and 0.03-0.3 g L(-1), the uptake of ginsenoside Rg1 and Rb1 was separately linearly increased (r >0.999), and no changes of K(a) absorption fraction and t(1/2) are found. The pH of flux has no effect on drug absorption. Ginsenoside Rg1 can be absorbed in the whole intestine and no changes of K(a), absorption fraction and t(1/2) refound and all the parameters of ginsenoside Rb1 at jejunum are higher than that at ileum and duodenum (P <0. 5). Further more, P-gp inhibitor verapamil has obvious effect on the intestinal absorption of ginsenoside Rb1 (P <0.5) while it has no effect on ginsenoside Rg1.
  
  
  CONCLUSIONS
  The absorption of ginsenoside Rg1 and Rb1 in intestine of rat are first-order kinetics, the absorption mechanism is infered the passive diffusion. Ginsenoside Rg1 has no specific absorption locus in intestine of rat and ginsenoside Rb1 has specific absorption locus of jejunum. Meanwhile, ginsenoside Rb1 is the P-gp substrate, and could increase its fraction of bioavailability by corporation with P-gp inhibitor.
authors.affiliation: Engineering Research Center of Natural Anticancer Drugs, Ministry of Education, Harbin University of Commerce, Harbin, China. lwldzd@163.com
authors.forename: Wenlan
authors.initials: W
authors.lastname: Li
authors.forename: Lili
authors.initials: L
authors.lastname: Nan
authors.forename: Yubin
authors.initials: Y
authors.lastname: Ji
authors.forename: Xiangming
authors.initials: X
authors.lastname: Sun
authors.forename: Zhi
authors.initials: Z
authors.lastname: Sun
mesh_terms: D000818:Animals; D004365:Drugs, Chinese Herbal / Q000493:pharmacokinetics*; D005260:Female; D036145:Ginsenosides / Q000493:pharmacokinetics*; D007408:Intestinal Absorption; D007422:Intestines / Q000502:physiology; D023421:Models, Animal; D005894:Panax / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar
chemical_list: D004365:Drugs, Chinese Herbal; D036145:Ginsenosides; C442759:ginsenoside Rb1; C035054:ginsenoside Rg1