RT Journal Article SR Electronic T1 Modulation of Multidrug Resistance and Apoptosis of Cancer Cells by Selected Carotenoids JF In Vivo JO In Vivo FD International Institute of Anticancer Research SP 237 OP 244 VO 18 IS 2 A1 JOSEPH MOLNAR A1 NORA GYÉMANT A1 ILONA MUCSI A1 ANNAMARIA MOLNAR A1 MARGARET SZABo A1 TAMAS KÖRTVÉLYESI A1 ANDRAS VARGA A1 PÉTER MOLNAR A1 GYULA TOTH YR 2004 UL http://iv.iiarjournals.org/content/18/2/237.abstract AB The multidrug resistance (MDR) proteins that belong to the ATP-binding casette superfamily are present in a majority of human tumors and are an important final cause of therapeutic failure. Therefore, compounds which inhibit the function of the MDR-efflux proteins may improve the cytotoxic action of anticancer chemotherapy. The effects of carotenoids were studied on the activity of the MDR-1 gene-encoded efflux pump system. The carotenoids, isolated from paprika and other vegetables, were tested on the rhodamine 123 accumulation of human MDR-1 gene-transfected L1210 mouse lymphoma cells and human breast cancer cells MDA-MB-231 (HTB-26). Capsanthin and capsorubin enhanced the rhodamine 123 accumulation 30-fold relative to nontreated lymphoma cells. Lycopene, lutein, antheraxanthin and violaxanthin had moderate effects, while alfa- and beta-carotene had no effect on the reversal of MDR in the tumor cells. Apoptosis was induced in human MDR1 transfected mouse lymphoma cells and human breast cancer MDA-MB-231 (HTB-26) cell lines in the presence of lycopene, zeaxanthin and capsanthin. The data suggest the potential of carotenoids as possible resistance modifiers in cancer chemotherapy. Copyright © 2004 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved