Abstract:

Multidrug resistance (MDR) in tumor cells can reduce the efficacy of chemotherapy. Overexpression of transporters is an important mechanism for MDR. P-glycoprotein (P-gp) is an ATP-binding cassette transporter frequently expressed in multidrugresistant tumor cells, inducing MDR. To reverse P-gp dependent MDR, anticancer drugs can be administered with P-gp inhibitors. Piperine and (R)-(+)-citronellal both are P-gp inhibitors from dietary sources. In the present study, we aimed to evaluate the MDR reversal effects of piperine and (R)-(+)-citronellal in multidrug resistant MCF-7/DOX cells. The results of cytotoxicity studies indicated that piperine and (R)-(+)-citronellal both could abate the resistance of MCF-7/DOX after 72-h incubation. After 72-h incubation, piperine could dose-dependently down-regulate the MDR1 expression at the mRNA level, while (R)-(+)-citronellal had no effect on the MDR1 expression. Therefore, piperine and (R)-(+)-citronellal both could reverse MDR in MCF-7/DOX cells, and the reversal effect of piperine was related to dose-dependent down-regulation of the MDR1 expression at the mRNA level.

Key words: MDR1, Piperine, (R)-(+)-Citronellal, MCF-7/DOX, P-Glycoprotein