Document Type

Article

Publication Date

1-9-2013

Journal or Book Title

Planta Medica

Volume

79

First Page

266

Last Page

274

DOI

10.1055/s-0032-1328198

Abstract

The use of Echinacea as a medicinal herb is prominent in the United States, and many studies have assessed the effectiveness of Echinacea as an immunomodulator. We hypothesized that Bauer alkamides 8, 10, and 11 and ketone 24 were absorbed similarly either as pure compounds or from Echinacea sanguinea and Echinacea pallida ethanol extracts, and that these Echinacea extracts could inhibit the P-glycoprotein transporter in Caco-2 human intestinal epithelial cells. Using HPLC analysis, the permeation rate of Bauer alkamides by passive diffusion across Caco-2 cells corresponded with compound hydrophilicity (alkamide 8 > 10 > 11), independent of the plant extract matrix. Both Echinacea ethanol extracts stimulated apparent glucuronidation and basolateral efflux of glucuronides of alkamides 8 and 10 but not alkamide 11. Bauer ketone 24 was totally metabolized to more hydrophilic metabolites when administered as a single compound, but was also glucuronidated when present in Echinacea extracts. Bauer alkamides 8, 10, and 11 (175– 230 μM) and ethanol extracts of E. sanguinea (1 mg/mL, containing ~ 90 μM total alkamides) and E. pallida (5 mg/mL, containing 285 μM total alkamides) decreased the efflux of the P-glycoprotein transporter probe calcein-AM from Caco- 2 cells. These results suggest that other constituents in these Echinacea extracts facilitated the metabolism and efflux of alkamides and ketones, which might improve therapeutic benefits. Alkamides and Echinacea extracts might be useful in potentiating some chemotherapeutics, which are substrates for the P-glycoprotein transporter.

Comments

This article is from Planta Medica 79 (2013): 266, doi:10.1055/s-0032-1328198, Posted with Permission.

Rights

Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.

Copyright Owner

Georg Thieme Verlag KG Stuttgart · New York ·

Language

en

File Format

application/pdf

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