title: New MDR modulators and apoptosis inducers from Euphorbia species.
abstract: Several macrocyclic diterpenes with jatrophane or lathyrane skeletons were isolated from methanol extracts of Hungarian Euphorbia species and evaluated for multidrug resistance (MDR)-reversing activity on a human colon cancer cell line. MDR-reversing activity was tested by using a standard functional assay with Rhodamine 123 as a fluorescent substrate analogue of epirubicin. In the model of combination chemotherapy, the interactions between epirubicin and certain resistance modifiers were studied in vitro. Compound 8 proved to be the most active, exhibiting a synergistic interaction. The capacity of the most effective derivative to induce apoptosis was demonstrated by flow cytometric analysis and by staining with ethidium bromide and acridine orange, using human mdrl gene-transfected mouse lymphoma cells and a human cervical adenocarcinoma cell line. The selected diterpene was able to induce moderate apoptosis in the tested cell lines. The data presented here indicate that naturally occurring Euphorbia diterpenes can be regarded as effective lead compounds for the reversal of MDR.
authors.affiliation: Department of Medical Microbiology and Immunobiology, Faculty of Medicine, University of Szeged, Hungary.
authors.forename: Helga
authors.initials: H
authors.lastname: Engi
authors.forename: Andrea
authors.initials: A
authors.lastname: Vasas
authors.forename: Dóra
authors.initials: D
authors.lastname: Rédei
authors.forename: Joseph
authors.initials: J
authors.lastname: Molnár
authors.forename: Judit
authors.initials: J
authors.lastname: Hohmann
mesh_terms: D000165:Acridine Orange; D017209:Apoptosis / Q000187:drug effects*; D048708:Cell Growth Processes / Q000187:drug effects; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000473:pathology; D004224:Diterpenes / Q000302:isolation & purification / Q000494:pharmacology*; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D004996:Ethidium; D028481:Euphorbia / Q000737:chemistry*; D006801:Humans; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology; D013194:Staining and Labeling / Q000379:methods
chemical_list: D004224:Diterpenes; D010936:Plant Extracts; D004996:Ethidium; D000165:Acridine Orange