These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Pervilleine A, a novel tropane alkaloid that reverses the multidrug-resistance phenotype.
    Author: Mi Q, Cui B, Silva GL, Lantvit D, Lim E, Chai H, You M, Hollingshead MG, Mayo JG, Kinghorn AD, Pezzuto JM.
    Journal: Cancer Res; 2001 May 15; 61(10):4030-7. PubMed ID: 11358822.
    Abstract:
    P-Glycoprotein-mediated drug efflux can yield a multidrug-resistance (MDR) phenotype that is associated with a poor response to cancer chemotherapy. Pervilleine A, a novel tropane alkaloid obtained from a chloroform extract of Erythroxylum pervillei as the result of bioactivity-guided fractionation, was found to restore the vinblastine sensitivity of cultured multidrug-resistant KB-V1 and CEM/VLB(100) cells, with IC(50) values of 0.36 and 0.02 microM, respectively. Similarly, the chemosensitivity of KB-8-5 cells to colchicine was restored with an IC(50) value of 0.61 microM. The mechanism of this response was evaluated with a number of model systems. First, incubation of multidrug-resistant KB-V1 and CEM/VLB(100) cells with up to 45 microM pervilleine A for 72 h did not significantly affect either the transcription of MDR1, as revealed by reverse transcriptional-PCR-based analysis of MDR1 mRNA, or levels of P-glycoprotein, as shown by Western blots. ATP-dependent binding of [(3)H]vinblastine observed with isolated multidrug-resistant KB-V1 cell membrane vesicles was inhibited by pervilleine A in a dose-dependent manner, and kinetic analysis indicted competitive inhibition with respect to vinblastine binding with a K(i) of 7.3 microM. Consistent with this effect, intracellular accumulation of [(3)H]vinblastine was increased from 0.18 pmol [(3)H]vinblastine/50 x 10(4) cells to approximately 5 pmol [(3)H]vinblastine/50 x 10(4) cells in the presence of 40 microM pervilleine A. To explore the potential relevance of these responses, KB-V1 or KB-8-5 cells were placed in hollow fibers and implanted into NCr nu/nu mice. Cell growth was not significantly inhibited when vinblastine or pervilleine A were administered as single agents, but when used in combination, inhibition of up to 75% was observed. Equimolar doses of verapamil were less effective. These data suggest that pervilleine A is an effective inhibitor of P-glycoprotein and should be further evaluated for clinical utility.
    [Abstract] [Full Text] [Related] [New Search]