title: Antiproliferative and apoptotic activities of extracts of Asclepias subulata.
abstract: BACKGROUND
  Asclepias subulata Decne. (Apocynaceae) is a shrub used in the Mexican traditional medicine for the treatment of cancer.
  
  
  OBJECTIVE
  The objective of this study was to evaluate the antiproliferative activity of methanol extract of aerial parts of A. subulata and its fractions against different cancer cell lines. Additionally, we analyzed the mechanism of action of the active fractions.
  
  
  METHODS
  Methanol extract fractions were prepared by serial extraction with n-hexane, ethyl acetate, and ethanol. The antiproliferative activity of methanol extract and its fractions was evaluated, against several murine (M12.C3.F6, RAW 264.7, and L929) and human (HeLa, A549, PC-3, LS 180, and ARPE-19) cell lines by the MTT assay, using concentrations of 0.4-400 µg/mL for 48 h. Ethanol and residual fractions were separated using silica gel column. Apoptosis induction of cancer cells was evaluated by Annexin and JC-1 staining using flow cytometry.
  
  
  RESULTS
  Methanol extract and its fractions showed antiproliferative activity against all human cancer cell lines tested. Methanol extract had the highest antiproliferative activity on A549 and HeLa cells (IC50 values < 0.4 and 8.7 µg/mL, respectively). Ethanol and residual fractions exerted significant antiproliferative effect on A549 (IC50 < 0.4 µg/mL) and PC3 cells (IC50 1.4 and 5.1 µg/mL). Apoptotic assays showed that CEF7, CEF9, CRF6, and CRF5 fractions induced mitochondrial depolarization in A549 cells, 70, 73, 77, and 80%, respectively. Those fractions triggered the apoptosis mitochondrial pathway.
  
  
  CONCLUSIONS
  Our data show that A. subulata extracts have potent antiproliferative properties on human cancer cell lines. This plant should be considered an important source of potent anticancer compounds.
authors: Departamento de Investigaciones Científicas y Tecnológicas de la Universidad de Sonora , Hermosillo, Sonora , México .
authors: Luisa Alondra
authors: LA
authors: Rascón Valenzuela
authors: Manuel
authors: M
authors: Jiménez Estrada
authors: Carlos Arturo
authors: CA
authors: Velázquez Contreras
authors: Adriana
authors: A
authors: Garibay Escobar
authors: Luis Angel
authors: LA
authors: Medina Juárez
authors: Nohemi
authors: N
authors: Gámez Meza
authors: Ramón Enrique
authors: RE
authors: Robles Zepeda
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D031108:Asclepias; D049109:Cell Proliferation / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D035264:Flowers; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D010936:Plant Extracts / Q000302:isolation & purification* / Q000494:pharmacology*; D018547:Plant Stems
chemical_list: D010936:Plant Extracts
keywords: Apoptosis; active fractions; cancer cell lines