title: Heat Killed Attenuated Leishmania Induces Apoptosis of HepG2 Cells Through ROS Mediated p53 Dependent Mitochondrial Pathway.
abstract: OBJECTIVE
  Cytotoxic effect of attenuated Leishmania on liver cancer cells by inducing ROS generation.
  
  
  METHODS
  Spectrophotometric study to analyze cell death and levels of different active caspases. Flow cytometric study was done to analyze apoptosis induction and ROS generation and levels of different protein. Western blot analysis was performed to study the levels of protein. Confocal microscopy was done to ascertain the expression of different apoptotic markers.
  
  
  RESULTS
  We have now observed that attenuated Leishmania donovani UR6 also has potentiality towards growth inhibition of HepG2 cells and investigated the mechanism of action. The effect is associated with increased DNA fragmentation, rise in number of annexinV positive cells, and cell cycle arrest at G1 phase. The detection of unregulated levels of active PARP, cleaved caspases 3 and 9, cytosolic cytochrome C, Bax, and Bad, along with the observed downregulation of Bcl-2 and loss of mitochondrial membrane potential suggested the involvement of mitochondrial pathway. Enhanced ROS and p53 levels regulate the apoptosis of HepG2 cells. NAC was found to inhibit p53 production but PFT-α has no effect on ROS generation. In conclusion, Leishmania donovani UR6 efficiently induces apoptosis in HepG2 cells through ROS mediated p53 dependent mitochondrial pathway.
  
  
  CONCLUSIONS
  It has been reported earlier that some parasites show prominent cytotoxic effect and prevent tumor growth. From our study we found that Leishmania donovani UR6 efficiently induced apoptosis in HepG2 cells through ROS mediated p53 dependent mitochondrial pathway. This study has rejuvenated the age old idea of bio-therapy.
authors.forename: Dipayan
authors.initials: D
authors.lastname: Bose
authors.forename: Somenath
authors.initials: S
authors.lastname: Banerjee
authors.forename: Subhadip
authors.initials: S
authors.lastname: Das
authors.forename: Nabanita
authors.initials: N
authors.lastname: Chatterjee
authors.forename: Krishna Das
authors.initials: KD
authors.lastname: Saha
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D017209:Apoptosis; D002118:Calcium / Q000378:metabolism; D053148:Caspase 3 / Q000032:analysis / Q000378:metabolism; D053453:Caspase 9 / Q000032:analysis / Q000378:metabolism; D045304:Cytochromes c / Q000378:metabolism; D053938:DNA Fragmentation; D015536:Down-Regulation; D059585:G1 Phase Cell Cycle Checkpoints; D056945:Hep G2 Cells; D006358:Hot Temperature; D006801:Humans; D007891:Leishmania / Q000472:pathogenicity*; D053078:Membrane Potential, Mitochondrial; D008928:Mitochondria / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects; D051028:bcl-2-Associated X Protein / Q000378:metabolism; D051025:bcl-Associated Death Protein / Q000378:metabolism
chemical_list: D019253:Proto-Oncogene Proteins c-bcl-2; D017382:Reactive Oxygen Species; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein; D051025:bcl-Associated Death Protein; D045304:Cytochromes c; D053148:Caspase 3; D053453:Caspase 9; D002118:Calcium; D000111:Acetylcysteine