In vivo: |
Planta Medica, 2011, 77(16):1794-1799. | Absolute/relative bioavailability and metabolism of dodeca-2E,4E,8Z,10E/Z-tetraenoic acid isobutylamides (tetraenes) after intravenous and oral single doses to rats.[Reference: WebLink] | The present study assessed the absolute and relative bioavailabilities of Dodeca 2E,4E,8Z,10E,Z-tetraenoic acid isobutylamide (tetraenes), the main bioactive constituents in Echinacea, administered as pure compounds or in the form of an Echinacea purpurea root extract preparation.
METHODS AND RESULTS:
Tetraenes were administered orally by gavage or intravenously in a dose of 0.75 mg/kg. The extract was administered orally in a dose of 158.6 mg/kg which corresponds to the same amount of tetraenes. Pharmacokinetic parameters of tetraenes were calculated by non-compartmental analysis using WinNonlin® 5.2 software. Mean dodeca-2 E,4 E,8 Z,10 E/ Z-tetraenoic acid isobutylamide dose-normalized plasma area under the concentration-time curve (AUC₀-∞/dose) was 3.24 ± 0.32 min · ng/mL/µg and 0.95 ± 0.16 min · ng/mL/µg after iv and oral administrations, respectively, and 1.53 ± 0.18 min · ng/mL/µg after oral administration of the Echinacea root extract. The absolute oral bioavailability of dodeca-2 E,4 E,8 Z,10 E/ Z-tetraenoic acid isobutylamides was 29.2 ± 2.3 %, which was increased to 47.1 ± 7.2 % (1.6-fold) by administration of the Echinacea extract.
CONCLUSIONS:
Administration of an Echinacea extract increased blood exposure with no impact on C(max), but prolonged the elimination half-life to 123.3 ± 15.7 min in comparison to 35.8 ± 6.5 min after administration of the pure dodeca-2 E,4 E,8 Z,10 E/ Z-tetraenoic acid isobutylamides. |
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