Reversal effect of isotetrandrine, an isoquinoline alkaloid extracted from Caulis Mahoniae, on P-glycoprotein-mediated doxorubicin-resistance in human breast cancer (MCF-7/DOX) cells.
- Author:
Tian-Xiao WANG
1
;
Xiao-Hong YANG
Author Information
1. Institute of Pharmacy, Henan University, Kaifeng 475004, China. wtx1975@henu.edu.cn
- Publication Type:Journal Article
- MeSH:
ATP-Binding Cassette, Sub-Family B, Member 1;
metabolism;
Antineoplastic Agents, Phytogenic;
isolation & purification;
pharmacology;
Benzylisoquinolines;
isolation & purification;
pharmacology;
Breast Neoplasms;
pathology;
Cell Line, Tumor;
Doxorubicin;
pharmacology;
Drug Resistance, Multiple;
drug effects;
Drug Resistance, Neoplasm;
drug effects;
Drugs, Chinese Herbal;
isolation & purification;
pharmacology;
Gene Expression Regulation, Neoplastic;
Genes, MDR;
Humans;
Mahonia;
chemistry;
Plant Stems;
chemistry;
Plants, Medicinal;
chemistry;
Rhodamine 123;
metabolism
- From:
Acta Pharmaceutica Sinica
2008;43(5):461-466
- CountryChina
- Language:English
-
Abstract:
This study investigated the reversal effect of isotetrandrine, an isoquinoline alkaloid extracted from Caulis mahoniae, on P-glycoprotein-mediated multidrug resistance in human breast cancer doxorubicin-resistant (MCF-7/DOX) cells. RT-PCR assay and immunity histochemistry assay were used to determine the expression level of mdrl gene and P-gp in MCF-7/DOX cells to elucidate resistant character of MCF-7/DOX cells. The activity of isotetrandine to enhance doxorubicin cytotoxicity was tested using MTT (3-(4, 5-dimethyhthiazol)-2,5 -diphenyltetrazolium bromide) assay and was evaluated by the reversal fold (RF) values. Intracellular accumulation of doxorubicin was assessed by the determination of doxorubicin-associated fluorescence intensity. Effect of isotetrandrine on the expression level of P-gp in MCF-7/DOX cells was then determined by immunity histochemistry assay. The ability of isotetrandrine to inhibit P-gp function was evaluated by detecting the accumulation and efflux of rhodamine 123 (Rh123) with flow cytometry (FCM). Verapamil was employed as a comparative agent in whole experiment. The results indicated that MCF-7/DOX cells had phenotype of MDR and that the positive expression of P-gp was their resistant character. 10 microg x mL(-1) isotetrandrine could distinctly enhance cytotoxicity of DOX in MCF-7/DOX cells and reversal fold (RF) was significantly higher than that of verapamil (P < 0.05), but it hardly affected cytotoxicity of DOX in MCF-7 cells and the expression level of P-gp in MCF-7/DOX cells. The ability of isotetrandrine to inhibit P-gp function was reversible, because incubation of MCF-7/DOX cells with isotetrandrine caused a marked increase in uptake and a notable decrease in efflux of Rh123 and a marked increase of intracellular DOX concentrations. In conclusion, isotetrandrine exhibited potent effect on the reversal of P-gp-mediated MDR in vitro, suggesting that it might become a candidate of effective MDR reversing agent in cancer chemotherapy.
