title: Investigation of Ehrlich ascites tumor cell death mechanisms induced by Synadenium umbellatum Pax.
abstract: BACKGROUND
  Synadenium umbellatum Pax. is widely found in South America and empirically used in Brazil for the treatment of several diseases, mainly cancer. The aim of the study was to investigate cell death mechanisms induced by Synadenium umbellatum Pax. using Ehrlich ascites tumor (EAT) cells, as well as the myelotoxicity potential of this plant.
  
  
  METHODS
  S. umbellatum cytotoxicity was evaluated in EAT cells by trypan blue exclusion and MTT reduction test and the mechanisms involved in EAT cell death were investigated by light and fluorescence microscopy, flow cytometry and immunocytochemistry. Investigation of S. umbellatum myelotoxicity was performed by clonogenic assay of colony forming unit- granulocyte macrophage (CFU-GM).
  
  
  CONCLUSIONS
  Our results demonstrated that S. umbellatum decreased the viability of EAT cells using both methods. Morphological analyses revealed that S. umbellatum-treatment induced EAT cell death by apoptotic pathway. We demonstrated the occurrence of reactive oxygen species (ROS) overgeneration, increased intracellular Ca(2+) concentration, alteration in mitochondrial membrane potential, phosphatydylserine externalization, and activation of caspases 3, 8, and 9. However, S. umbellatum produced myelotoxicity in bone marrow cells in a concentration-dependent manner. In comparison to EAT cells, the effects of S. umbellatum in bone marrow cells were 8-fold lower. Taken together, our results showed that S. umbellatum induced apoptosis in EAT cells at several levels and seems more toxic to tumor cells than to normal bone marrow cells.
authors.affiliation: Laboratório de Farmacologia e Toxicologia Celular, Faculdade de Farmácia, Universidade Federal de Goiás, UFG, Goiânia, GO, Brazil.
authors.forename: Mariana Flavia
authors.initials: MF
authors.lastname: da Mota
authors.forename: Polyana Lopes
authors.initials: PL
authors.lastname: Benfica
authors.forename: Aline Carvalho
authors.initials: AC
authors.lastname: Batista
authors.forename: Frederico Severino
authors.initials: FS
authors.lastname: Martins
authors.forename: José Realino
authors.initials: JR
authors.lastname: de Paula
authors.forename: Marize Campos
authors.initials: MC
authors.lastname: Valadares
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology* / Q000633:toxicity; D017209:Apoptosis / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism; D002286:Carcinoma, Ehrlich Tumor / Q000378:metabolism / Q000473:pathology*; D053148:Caspase 3 / Q000378:metabolism; D053181:Caspase 8 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D019665:Euphorbiaceae; D005434:Flow Cytometry; D055014:Granulocyte-Macrophage Progenitor Cells / Q000187:drug effects / Q000473:pathology; D007150:Immunohistochemistry; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051379:Mice; D008856:Microscopy, Fluorescence; D018384:Oxidative Stress / Q000187:drug effects; D010718:Phosphatidylserines / Q000378:metabolism; D035261:Plant Components, Aerial; D010946:Plants, Medicinal; D017382:Reactive Oxygen Species / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D010718:Phosphatidylserines; D017382:Reactive Oxygen Species; C505409:Casp3 protein, mouse; C505526:Casp8 protein, mouse; C506434:Casp9 protein, mouse; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D002118:Calcium