title: Condurango (Gonolobus condurango) Extract Activates Fas Receptor and Depolarizes Mitochondrial Membrane Potential to Induce ROS-dependent Apoptosis in Cancer Cells in vitro: CE-treatment on HeLa: a ROS-dependent mechanism.
abstract: OBJECTIVE
  Condurango (Gonolobus condurango) extract is used by complementary and alternative medicine (CAM) practitioners as a traditional medicine, including homeopathy, mainly for the treatment of syphilis. Condurango bark extract is also known to reduce tumor volume, but the underlying molecular mechanisms still remain unclear.
  
  
  METHODS
  Using a cervical cancer cell line (HeLa) as our model, the molecular events behind condurango extract's (CE's) anticancer effect were investigated by using flow cytometry, immunoblotting and reverse transcriptase-polymerase chain reaction (RT-PCR). Other included cell types were prostate cancer cells (PC3), transformed liver cells (WRL-68), and peripheral blood mononuclear cells (PBMCs).
  
  
  RESULTS
  Condurango extract (CE) was found to be cytotoxic against target cells, and this was significantly deactivated in the presence of N-acetyl cysteine (NAC), a scavenger of reactive oxygen species (ROS), suggesting that its action could be mediated through ROS generation. CE caused an increase in the HeLa cell population containing deoxyribonucleic acid (DNA) damage at the G zero/Growth 1 (G0/G1) stage. Further, CE increased the tumor necrosis factor alpha (TNF-α) and the fas receptor (FasR) levels both at the ribonucleic acid (RNA) and the protein levels, indicating that CE might have a cytotoxic mechanism of action. CE also triggered a sharp decrease in the expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB ) both at the RNA and the protein levels, a possible route to attenuation of B-cell lymphoma 2 (Bcl-2), and caused an opening of the mitochondrial membrane's permeability transition (MPT) pores, thus enhancing caspase activities.
  
  
  CONCLUSIONS
  Overall, our results suggest possible pathways for CE mediated cytotoxicity in model cancer cells.
authors.affiliation: Cytogenetics and Molecular Biology Laboratory, Department of Zoology, University of Kalyani, Kalyani, India.
authors.forename: Kausik
authors.initials: K
authors.lastname: Bishayee
authors.affiliation: Cytogenetics and Molecular Biology Laboratory, Department of Zoology, University of Kalyani, Kalyani, India.
authors.forename: Jesmin
authors.initials: J
authors.lastname: Mondal
authors.affiliation: Cytogenetics and Molecular Biology Laboratory, Department of Zoology, University of Kalyani, Kalyani, India.
authors.forename: Sourav
authors.initials: S
authors.lastname: Sikdar
authors.affiliation: Cytogenetics and Molecular Biology Laboratory, Department of Zoology, University of Kalyani, Kalyani, India.
authors.forename: Anisur Rahman
authors.initials: AR
authors.lastname: Khuda-Bukhsh
keywords: G0/G1 arrest; apoptosis; condurango extract; cytotoxicity; reactive oxygen species