title: Cytotoxic effect and its mechanism of dioscorealide B from Dioscorea membranacea against breast cancer cells.
abstract: BACKGROUND
  Dioscorealide B is an active compound from the rhizome of Dioscorea membranacea Pierre which locally known as "Hua-Khao-Yen". This medicinal plant has long been used in the anticancer prescription of Thai traditional medicine.
  
  
  OBJECTIVE
  To examine the cytotoxic effect and mechanism of Dioscorealide B in human breast carcinoma cells.
  
  
  METHODS
  Dioscorealide B was isolated from the rhizome of Hua KhaoYen (Dioscorea membranacea).The cytotoxicity of Dioscorealide B was evaluated in two human breast cancer cell lines, MCF-7 and MDA-MB 468 by Sulphorhodamine B (SRB) assay. RT-PCR and Caspase-Glo assay were used to further elucidate its cytotoxic mechanism.
  
  
  RESULTS
  Dioscorealide B showed cytotoxic effect on MCF-7 (IC50 = 2.76 microM) and MDA-MB 468 (IC50 = 9.93 microM). The mRNA level for p53, p21 and Bax were increased while Bcl-2 was decreased after the treatment. MCF-7 treated with Dioscorealide B showed the induction of apoptosis via the activation of caspase-9 and -7.
  
  
  CONCLUSIONS
  The results suggested that the mechanisms of Dioscorealide B might be involved in p53 and the intrinsic apoptotic pathway.
authors.affiliation: Department of Biomedical Sciences, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand.
authors.forename: Jiraporn
authors.initials: J
authors.lastname: Saekoo
authors.forename: Chavaboon
authors.initials: C
authors.lastname: Dechsukum
authors.forename: Potchanapond
authors.initials: P
authors.lastname: Graidist
authors.forename: Arunporn
authors.initials: A
authors.lastname: Itharat
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D045744:Cell Line, Tumor / Q000187:drug effects*; D027742:Dioscorea / Q000737:chemistry*; D006576:Heterocyclic Compounds, 4 or More Rings / Q000494:pharmacology* / Q000633:toxicity; D006801:Humans; D020128:Inhibitory Concentration 50; D010936:Plant Extracts / Q000494:pharmacology*; D010946:Plants, Medicinal; D020133:Reverse Transcriptase Polymerase Chain Reaction; D027343:Rhizome / Q000737:chemistry; D013785:Thailand
chemical_list: D006576:Heterocyclic Compounds, 4 or More Rings; D010936:Plant Extracts; C516706:dioscorealide B