title: Screening of some saponins and phenolic components of Tribulus terrestris and Smilax excelsa as MDR modulators.
abstract: BACKGROUND
  Cytotoxic activity of saponins and phenolic compounds have been described in the literature, but no reports were found on their multidrug resistance (MDR)-modulating effects on human mdr1 gene-transfected mouse lymphoma cell line.
  
  
  METHODS
  Methylprototribestin, structurally related compounds and a mixture of 3 acetylated isomers of methylprotodioscin were investigated for antiproliferative effect and modulation of drug accumulation.
  
  
  RESULTS
  The growth inhibitory dose (ID50) of the compounds ranged from 12.64 to 20.62 mug/ml. Methylprototribestin was the most effective resistance modifier. However, methylprotodioscin, pseudoprotodioscin, prosapogenin A of dioscin, tribestin and 5-O-caffeoylshikimic acid showed moderate MDR reversal activity. In a checkerboard method, methyloprototribestin and the mixture of the 3 acetylated isomers enhanced the antiproliferative effects on MDR cells in combination with doxorubicin.
  
  
  CONCLUSIONS
  Based on these results, methylprototribestin and the mixture of the 3 acetylated isomers can be recommended for further in vivo experiments in combination with anthracyclines in human MDR-cancer xenograft transplanted mice.
authors: Institute of Organic Chemistry With Center of Phytochemistry, Bulgarian Academy of Sciences, Sofia, Bulgaria.
authors: Antoaneta
authors: A
authors: Ivanova
authors: Julianna
authors: J
authors: Serly
authors: Dragomir
authors: D
authors: Dinchev
authors: Imre
authors: I
authors: Ocsovszki
authors: Ivanka
authors: I
authors: Kostova
authors: Joseph
authors: J
authors: Molnar
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D045744:Cell Line, Tumor; D015195:Drug Design; D006801:Humans; D016399:Lymphoma, T-Cell; D051379:Mice; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D012503:Saponins / Q000737:chemistry / Q000494:pharmacology*; D032281:Smilax / Q000737:chemistry*; D014162:Transfection; D032444:Tribulus / Q000737:chemistry*; D023041:Xenograft Model Antitumor Assays
chemical_list: C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D010636:Phenols; D010936:Plant Extracts; D012503:Saponins