Investigation of fractions present in the stem bark of Annickia kummeriae on their P-glycoprotein inhibitory pump activity.
Phytother Res
; 18(8): 652-7, 2004 Aug.
Article
em En
| MEDLINE
| ID: mdl-15476303
ABSTRACT
Using MCF-7R cells and rhodamine 6G as the fluorescent probe, a bioassay-targeted purification process was pursued in order to isolate the active P-gp inhibitory fractions from Annickia kummeriae. Of 24 fractions obtained in the first preparative liquid chromatography (p-LC) run, only fraction 1 exhibited activity. Further p-LC fractionation led to the separation of fraction 1 into fractions 1.1-1.8. Fractions 1.4, 1.5 and 1.6 proved to be active by inducing a significant accumulation of rhodamine 6G by 3.3-, 4.5- and 4.9-fold at 10 microg/mL, and by 5.3-, 6.3- and 6.8-fold at 100 microg/mL, respectively. Fraction 1.6 was separated into several fractions by using an analytical liquid chromatography (a-LC) system. Fractions 1.6.18, 1.6.19 and 1.6.20 were active and they induced an accumulation of rhodamine 6G by 3.0-, 1.8- and 3.5-fold at 1x microg/mL and by 4.8-, 6.7- and 6.8-fold at 10x microg/mL, respectively. Afterwards, 28.3 mg of fraction 1.6 was processed by a-LC, and fractions 1.6.18, 1.6.19 and 1.6.20 were collected separately and dried. The amounts of materials recovered were 6.2, 7.4 and <1 mg, corresponding to 21.9%, 26.1% and <3.5% of fraction 1.6, respectively. From the total amount injected and the relative masses represented by these fractions, it can be calculated that the 1x microg/mL level corresponded to ca. 35, 42 and <5 microg/mL, respectively. Fluorescence microscopy revealed that incubation of the cells with rhodamine 6G alone did not show any fluorescence, whereas cells which were incubated in medium containing rhodamine 6G together with fraction 1.4, 1.6 or reserpine, clearly indicated accumulation of the dye intracellularly. This is an indication that the active compounds effected high intracellular fluorescence by inducing accumulation of the dye in the cells through inhibition of the P-gp pump.
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Base de dados:
MEDLINE
Assunto principal:
Extratos Vegetais
/
Membro 1 da Subfamília B de Cassetes de Ligação de ATP
/
Annonaceae
/
Fitoterapia
Idioma:
En
Ano de publicação:
2004
Tipo de documento:
Article