Curcumin down-regulates multidrug-resistance. - GreenMedInfo Summary
Curcumin down-regulates the multidrug-resistance mdr1b gene by inhibiting the PI3K/Akt/NF kappa B pathway.
Cancer Lett. 2008 Jan 18;259(1):111-8. Epub 2007 Nov 19. PMID: 18006147
Department of Biomedical Science and Technology, IBST, Konkuk University, Seoul 143-701, Republic of Korea.
Curcumin, a constituent of turmeric, has anti-inflammatory, anti-carcinogenic, and chemopreventive effects in several animal tumor models. The expression of P-glycoprotein (P-gp), encoded by the mdr gene, is often associated with multidrug resistance (MDR) to unrelated chemotherapeutic drugs in cancer cells. Here, we demonstrate that curcumin down-regulates P-gp expression in multidrug-resistant L1210/Adr cells. Transfection with a series of 5'-deleted constructs of the mdr1b gene promoter indicated that a proximal region between -205 and +42 of the sequence was responsible for the suppression of promoter activity by curcumin. This response might be associated with the inhibition of the phosphatidyinositol 3-kinase (PI3K)/Akt/nuclear factor-kappa B (NF-kappa B) signaling pathway by curcumin. Moreover, curcumin reversed the MDR of the L1210/Adr cells. Thus, curcumin can contribute to the reversal of the MDR phenotype, probably due to the suppression of P-gp expression via the inhibition of the PI3K/Akt/NF-kappa B signaling pathway.