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Planta Med 1999; 65(4): 307-310
DOI: 10.1055/s-1999-13991
Papers
Pharmacology
© Georg Thieme Verlag Stuttgart · New York

Reversal of Multidrug Resistance by Kopsiflorine Isolated from Kopsia dasyrachis

Mun-Chual Rho1 , Mitsuhide Toyoshima1 , Masahiko Hayashi1 , Takashi Koyano2 , Gurusamy Subramaniam3 , Toh-Seok Kam3 , Kanki Komiyama1
  • 1The Kitasato Institute, Shirokane, Minato-ku, Tokyo, Japan
  • 2Temko Corporation, Honcho, Nakano, Tokyo, Japan
  • 3Department of Chemistry, University of Malaya, Kuala Lumpur, Malaysia
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Publication History

1998

1998

Publication Date:
04 January 2007 (online)

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Abstract

Kopsiflorine, an indole alkaloid of the aspidofractinine-type isolated from Kopsia dasyrachis, was examined for its effect in enhancing drug cytotoxicity in multidrug-resistant tumor cells. The cytotoxicity of vincristine was enhanced in a concentration-dependent manner by kopsiflorine in drug-resistant KB cells (VJ-300). Kopsiflorine alone had no effect on the growth of drug sensitive or resistant cells, but the intracellular accumulation of vincristine was enhanced by kopsiflorine in VJ-300 cells. Kopsiflorine (10 µg/ml) significantly inhibited the binding of [3H]azidopine to P-glycoprotein in VJ-300 cells. The results suggest that kopsiflorine interacts directly with P-glycoprotein and inhibits the efflux of antitumor agents in drug-resistant cells.

Key words

Multidrug resistance - P-glycoprotein - kopsiflorine - Kopsia dasyrachis - Apocynaceae