title: Evaluation of the antitumoral effect of dihydrocucurbitacin-B in both in vitro and in vivo models.
abstract: OBJECTIVE
  We evaluated both in vitro and in vivo antitumoral properties of an isolated compound from Wilbrandia ebracteata, dihydrocucurbitacin-B (DHCB), using B16F10 cells (murine melanoma).
  
  
  METHODS
  We made use of MTT and (3)H-Thymidine assays to investigate the cell viability and cell proliferation, flow cytometry analysis to monitor cell cycle and apoptosis, western blot analysis to evaluate the expression of cell cycle proteins, imunofluorescence analysis and in vivo tumor growth and metastasis.
  
  
  RESULTS
  Dihydrocucurbitacin-B significantly reduced cell proliferation without important effects on cells viability. DHCB lead cells to accumulate in G2/M phases accompanied by the appearance of polyploid cells, confirmed by fluorescence assays that demonstrated a remarkable alteration in the cell cytoskeleton and formation of binuclear cells. Annexin-V-FITC incorporation demonstrated that DHCB did not induce apoptosis. About 10 microg/mL DHCB was found to decrease cyclin-A, and especially in cyclin-B1. The in vivo experiments showed that DHCB treatment (once a day up to 12 days; p.o.) was able to reduce the tumor growth and lung metastasis up to 83.5 and 50.3%, respectively.
  
  
  CONCLUSIONS
  Dihydrocucurbitacin-B reduces cell proliferation due to a decrease in the expression of cyclins, mainly cyclin-B1 and disruption of the actin cytoskeleton, arresting B16F10 cells in G2/M phase. Taken together, the in vitro and in vivo experiments suggest that DHCB was effective against cancer, however, it remains to be proved if DHCB will be a good candidate for drug development.
authors.affiliation: Department of Pharmacology, CCB, Bloco D, Federal University of Santa Catarina, Florianópolis, SC, Brazil. jarbasms@farmaco.ufsc.br
authors.forename: Jarbas Mota
authors.initials: JM
authors.lastname: Siqueira
authors.forename: Andressa Córneo
authors.initials: AC
authors.lastname: Gazola
authors.forename: Mareni Rocha
authors.initials: MR
authors.lastname: Farias
authors.forename: Lëonid
authors.initials: L
authors.lastname: Volkov
authors.forename: Nathalie
authors.initials: N
authors.lastname: Rivard
authors.forename: Artur José
authors.initials: AJ
authors.lastname: de Brum-Fernandes
authors.forename: Rosa Maria
authors.initials: RM
authors.lastname: Ribeiro-do-Valle
mesh_terms: D000199:Actins / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000302:isolation & purification / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D019662:Cucurbitaceae / Q000737:chemistry*; D016213:Cyclins / Q000187:drug effects / Q000378:metabolism; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D008297:Male; D008546:Melanoma, Experimental / Q000188:drug therapy*; D051379:Mice; D008810:Mice, Inbred C57BL; D009362:Neoplasm Metastasis; D014315:Triterpenes / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000199:Actins; D000972:Antineoplastic Agents, Phytogenic; D016213:Cyclins; D014315:Triterpenes; C523469:dihydrocucurbitacin B