title: Aqueous extract of Tribulus terrestris Linn induces cell growth arrest and apoptosis by down-regulating NF-κB signaling in liver cancer cells.
abstract: BACKGROUND
  A medicinal herb Tribulus terrestris Linn has been used to treat various diseases including hepatocellular carcinoma. The aim of the present study was to investigate the anticancer activity of Tribulus terrestris Linn (TT) in liver cancer cells.
  
  
  METHODS
  The antitumor activity of aqueous TT extract was analyzed by testing the cytotoxicity and the effect on clonogenecity in HepG2 cells. Apoptosis and cell cycle arrest induced by TT were dissected by flow cytometry and its inhibitory effect on NF-κB activity was determined by analyzing the expression levels of NF-κB/IκB subunit proteins. The suppression of NF-κB-regulated gene expression by TT was assessed by RT-PCR.
  
  
  RESULTS
  TT extract repressed clonogenecity and proliferation, induced apoptosis, and enhanced accumulation in the G0/G1 phase of liver cancer cells. It also turned out that TT extract inhibited NF-κB-dependent reporter gene expression and NF-κB subunit p50 expression, while it enhanced the cellular level of IκBα by inhibiting the phosphorylation and degradation of IκBα. In addition, IKK activity was inhibited in a dose-dependent manner. Furthermore, TT extract suppressed the transcription of genes associated with cell cycle regulation, anti-apoptosis, and invasion.
  
  
  CONCLUSIONS
  These data showed that TT extract blocks proliferation and induces apoptosis in human liver cancer cells through the inhibition of NF-κB signaling. Aqueous TT extract can be used as an anticancer drug for hepatocellular carcinoma patients.
authors.affiliation: Department of Microbiology, Chungnam National University, Daejeon 305-764, South Korea.
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Jin Chul
authors.initials: JC
authors.lastname: Kim
authors.forename: Jung Sun
authors.initials: JS
authors.lastname: Min
authors.forename: Mi-Jee
authors.initials: MJ
authors.lastname: Kim
authors.forename: Ji Ae
authors.initials: JA
authors.lastname: Kim
authors.forename: Myung Ho
authors.initials: MH
authors.lastname: Kor
authors.forename: Hwa Seung
authors.initials: HS
authors.lastname: Yoo
authors.forename: Jeong Keun
authors.initials: JK
authors.lastname: Ahn
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects / Q000235:genetics; D049109:Cell Proliferation / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D015870:Gene Expression; D017930:Genes, Reporter; D056945:Hep G2 Cells; D018197:Hepatoblastoma / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D051550:I-kappa B Kinase / Q000037:antagonists & inhibitors; D020672:I-kappa B Proteins / Q000378:metabolism; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism*; D009361:Neoplasm Invasiveness; D010766:Phosphorylation; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*; D015398:Signal Transduction / Q000187:drug effects; D032444:Tribulus; D014410:Tumor Stem Cell Assay
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D020672:I-kappa B Proteins; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D010936:Plant Extracts; D000072000:NF-KappaB Inhibitor alpha; D051550:I-kappa B Kinase