title: A novel steroid and cytotoxic constituents from Dioscorea membranacea Pierre against hepatocellular carcinoma and cholangiocarcinoma cells.
abstract: BACKGROUND
  The rhizomes of Dioscorea membrancea Pierre have been used in Thai traditional medicine as an ingredient formula for liver cancer and cholangiocarcinoma treatment.
  
  
  OBJECTIVE
  To investigate the cytotoxic activity of ethanolic extract and constituents of D. membrancea to support its traditional use.
  
  
  METHODS
  The SRB assay was used to determine the cytotoxic activity against hepatocellular carcinoma (HepG2), cholangiocarcinoma (KKU-M156) cells and one normal human keratinocyte immortal cells (HaCaT) with its ethanolic extract and isolated compounds. Bioassay guided isolation was used for isolating cytotoxic compounds.
  
  
  RESULTS
  The ethanolic extract of D. membranacea rhizome showed weak cytotoxic against KKU-M156 and HepG2 (IC50at 72h exposure=30.49±0.82 and 38.97±2.04µg/mL respectively). A new steroid [epipanthogenin B (1)], a known steroid [panthogenin B (2)], two napthofuranoxepins [dioscorealide A (3) and dioscorealide B (4)], phenanthraquinone [dioscoreanone (5)] and two phenanthrene [5,6-dihydroxy-2,4-dimethoxy-9,10-dihydrophenanthrene (6) and 2,5,6-trihydroxy-3,4-dimethoxy, 9, 10-dihydrophenanthrene (7)] were isolated from active chloroform fraction. Compound 4 showed the highest cytotoxicity against HepG2 (IC50at 72h exposure=2.87±0.21µM) and KKU-M156 (IC50at 72h exposure=1.67±0.10µM) and less toxicity against normal cell line (HaCaT) (IC50at 72h exposure>100µM). Compound 5 showed selective cytotoxic activity against KKU-M156 (IC50at 72h exposure=3.46±0.11µM). Compounds 6 and 7 showed weak cytotoxic activity against HepG2 (IC50at 72h exposure=24.96±2.32 and 51.31±3.52µM). Compounds (1-3) showed no cytotoxic activity against HepG2 and KKU-M156 cell lines (IC50at 72 h exposure>100µM).
  
  
  CONCLUSIONS
  Seven compounds were isolated from active chloroform fraction of the ethanolic extract of D. membranacea rhizomes. Only dioscorealide B (4) might be served as a good anticancer agent for liver cancer and cholangiocarcinoma cancer because it can kill cancer cell but not toxic on normal cell. This research support Thai traditional medicine use of D. membranacea for liver cancer and cholangiocarcinoma cancer treatment.
authors: Ph.D Program on Medical Science (Nutraceuticals), Graduate School, Faculty of Medicine, Thammasat University, Klongluang, Pathumthani 12120, Thailand.
authors: Pakakrong
authors: P
authors: Thongdeeying
authors: Department of Applied Thai Traditional Medicine, Faculty of Medicine, Thammasat University, Klongluang, Pathumthani 12120, Thailand; Center of Excellence in Applied Thai Traditional Medicine Research (CEATMR), Faculty of Medicine, Thammasat University, Klongluang, Pathumthani 12120, Thailand. Electronic address: iarunporn@yahoo.com.
authors: Arunporn
authors: A
authors: Itharat
authors: School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan.
authors: Kaoru
authors: K
authors: Umehara
authors: Department of Applied Thai Traditional Medicine, Faculty of Medicine, Thammasat University, Klongluang, Pathumthani 12120, Thailand; Center of Excellence in Applied Thai Traditional Medicine Research (CEATMR), Faculty of Medicine, Thammasat University, Klongluang, Pathumthani 12120, Thailand.
authors: Srisopa
authors: S
authors: Ruangnoo
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000494:pharmacology*; D001650:Bile Duct Neoplasms / Q000473:pathology*; D006528:Carcinoma, Hepatocellular / Q000473:pathology*; D045744:Cell Line, Tumor; D018281:Cholangiocarcinoma / Q000473:pathology*; D027742:Dioscorea / Q000737:chemistry*; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology*; D015394:Molecular Structure; D013057:Spectrum Analysis; D013256:Steroids / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D013256:Steroids
keywords: Cholangiocarcinoma; Cytotoxic activity; Dioscorea membranacea Pierre; Hepatocellular carcinoma; SRB assay