Inhibition of Intestinal Metabolism of the Antiviral Ester Prodrug bis(POC)-PMPA by Nature-Identical Fruit Extracts as a Strategy to Enhance Its Oral Absorption: An In Vitro Study
Purpose. To explore the usefulness of fruit extracts as enhancers of the oral absorption of esterase-sensitive prodrugs.
Methods. Inhibition of esterase-mediated degradation by nature-identical fruit extracts was evaluated using 1) p-nitrophenylacetate (model substrate for esterase-activity) in rat intestinal homogenates and 2) bis(isopropyloxycarbonyloxymethyl)-(R)-9-[(2-phosphonomethoxy) propyl]adenine [bis(POC)-PMPA] (esterase-sensitive prodrug of the antiviral agent PMPA) in Caco-2 cell homogenates and in intestinal homogenates from rat, pig and man. Subsequently, transport of the ester prodrug was studied across Caco-2 monolayers in the presence or absence of fruit extracts.
Results. In homogenates from rat ileum, the esterase activity could be reduced significantly by the inclusion of fruit extracts (1%): the initial enzymatic degradation of p-nitrophenylacetate was inhibited by 77% (strawberry), 16% (passion fruit) and 57% (banana). A similar inhibition of bis(POC)-PMPA metabolism by fruit extracts was observed in intestinal homogenates from several species and in homogenates from Caco-2 cells. Transport of total PMPA across Caco-2 monolayers was enhanced 3-fold by co-incubation with strawberry extract (1%). The fraction of intact prodrug appearing in the acceptor compartment increased from virtually zero to 67%.
Conclusions. The results suggest that co-incubation with nature-identical fruit extracts might be useful as a strategy to enhance the transepithelial transport of esterase-sensitive prodrugs through inhibition of intracellular metabolism of the prodrug.
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- Inhibition of Intestinal Metabolism of the Antiviral Ester Prodrug bis(POC)-PMPA by Nature-Identical Fruit Extracts as a Strategy to Enhance Its Oral Absorption: An In Vitro Study
Volume 16, Issue 7 , pp 1035-1040
- Cover Date
- Print ISSN
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- Kluwer Academic Publishers-Plenum Publishers
- Additional Links
- fruit extracts
- esterase inhibition
- ester prodrug
- Caco-2 cells
- absorption enhancer
- Industry Sectors
- Author Affiliations
- 1. Laboratorium voor Farmacotechnologie en Biofarmacie, Campus Gasthuisberg, O&N, KULeuven, Belgium
- 2. Rega Institute for Medical Research, Minderbroedersstraat 10, KULeuven, Belgium