Modulation of human multidrug-resistance MDR-1 gene by natural curcuminoids

BMC Cancer. 2004 Apr 17;4:13. doi: 10.1186/1471-2407-4-13.


Background: Multidrug resistance (MDR) is a phenomenon that is often associated with decreased intracellular drug accumulation in patient's tumor cells resulting from enhanced drug efflux. It is related to the overexpression of a membrane protein, P-glycoprotein (Pgp-170), thereby reducing drug cytotoxicity. A variety of studies have tried to find MDR modulators which increase drug accumulation in cancer cells.

Methods: In this study, natural curcuminoids, pure curcumin, demethoxycurcumin and bisdemethoxycurcumin, isolated from turmeric (Curcuma longa Linn), were compared for their potential ability to modulate the human MDR-1 gene expression in multidrug resistant human cervical carcinoma cell line, KB-V1 by Western blot analysis and RT-PCR.

Results: Western blot analysis and RT-PCR showed that all the three curcuminoids inhibited MDR-1 gene expression, and bisdemethoxycurcumin produced maximum effect. In additional studies we found that commercial grade curcuminoid (approximately 77% curcumin, 17% demethoxycurcumin and 3% bisdemthoxycurcumin) decreased MDR-1 gene expression in a dose dependent manner and had about the same potent inhibitory effect on MDR-1 gene expression as our natural curcuminoid mixtures.

Conclusion: These results indicate that bisdemethoxycurcumin is the most active of the curcuminoids present in turmeric for modulation of MDR-1 gene. Treatment of drug resistant KB-V1 cells with curcumin increased their sensitivity to vinblastine, which was consistent with a decreased MDR-1 gene product, a P-glycoprotein, on the cell plasma membrane. Although many drugs that prevent the P-glycoprotein function have been reported, this report describes the inhibition of MDR-1 expression by a phytochemical. The modulation of MDR-1 expression may be an attractive target for new chemosensitizing agents.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Curcumin / analogs & derivatives*
  • Curcumin / pharmacology*
  • Diarylheptanoids
  • Gene Expression / drug effects
  • Genes, MDR / drug effects*
  • Humans
  • Reverse Transcriptase Polymerase Chain Reaction


  • Diarylheptanoids
  • bis(4-hydroxycinnamoyl)methane
  • Curcumin
  • demethoxycurcumin