Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2008-2-18
pubmed:abstractText
The objective of this study was to examine the effect of ion-pair complexation with endogenous bile salts on the transport of a quarternary ammonium organic cationic (OC) drug, berberine, across the Caco-2 and LLC-PK1 cell monolayers. The basolateral-to-apical (BL-AP) transport of berberine in Caco-2 cells was temperature dependent and 10-fold higher than that of the apical-to-basolateral (AP-BL) transport. Similar results were observed for the transport of berberine across the LLC-PK1 cells. Moreover, the BL-AP transport in the Caco-2 cells was significantly reduced by the cis-presence of P-glycoprotein (P-gp) inhibitors such as cyclosporine A, verapamil, and digoxin. These results suggest that an efflux transporter, probably P-gp, is involved in the Caco-2 cell transport. The Km and Vmax values for the carrier-mediated transport were estimated to be 83.4 mM and 7640 pmole/h/cm2, respectively. The apparent partition coefficient (APC) of berberine between n-octanol and a phosphate buffer (pH 7.4) was increased by the presence of an organic anion (OA), taurodeoxycholate (TDC, a bile salt), suggesting the formation of a lipophilic ion-pair complex between an OC (berberine) and an OA (TDC). Despite the ion-pair complexation, however, the BL-AP transport of berberine across the Caco-2 and LLC-PK1 cells was not altered by the cis-presence of bile salts or the rat bile juice. This is consistent with the reportedly unaltered secretory transport of a quarternary ammonium compound, tributylmethylammonium (TBuMA), across the Caco-2 cell monolayers in the cis-presence of bile salts or the rat bile juice, but not with our previous report in which the secretory transport of TBuMA across the LLC-PK1 cell was increased in the cis-presence of TDC. Therefore, the effect of ion-pair formation with the bile components or bile salts on the secretory transport of OCs appears to depend on the molecular properties of OCs (e.g., molecular weight, lipophilicity and affinity to relevant transporters) and the characteristics of cell strains (e.g., expression and contribution of responsible transporters to the transport).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0253-6269
pubmed:author
pubmed:issnType
Print
pubmed:volume
31
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
103-10
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Effect of ion-pair formation with bile salts on the in vitro cellular transport of berberine.
pubmed:affiliation
National Research Laboratory for Transporters Targeted Drug Design, College of Pharmacy, Seoul National University, Seoul 151-742, Korea.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't