title: Protective effect of antioxidant enzymes against drug cytotoxicity in MCF-7 cells.
abstract: OBJECTIVE
  To evaluate protective effect of antioxidant enzymes against epirubicin-HCI (EPI) cytotoxicity in vitro.
  
  
  METHODS
  Viability of MCF-7 cells treated with EPI was measured using the MTT test. Glutathione (GSH), protein content and enzymatic activity were measured spectrophotometrically. NADPH - dependent cytochrome P-450 reductase (NADPH-CYP-450) and glutathione S-transferase pi (GST-pi) expression in MCF-7 cells were determined by Western blot analysis.
  
  
  RESULTS
  The IC50 values of EPI in MCF-7 cells were 1.0, 0.7 and 0.5 ng/ml respectively for 24, 48 and 72 h applications. Simultaneously enzymatic activity of glutathione S-transferase, glutathione peroxidase, GSH and expression of GST-pi, NADPH-CYP-450 reductase were increased in EPI (1 ng/ml) - treated cells at the end of the 24 h incubation. Addition of superoxide dismutase, catalase and GSH decreased cytotoxicity of EPI.
  
  
  CONCLUSIONS
  We hypothesized that the production of reactive oxygen species and hydrogen peroxide as result of EPI treatment can cause cytotoxicity in MCF-7 cells and antioxidant enzymes protect the cells against this process.
authors.affiliation: Akdeniz University, Art-Science Faculty, Biology Department, Antalya, Turkey. aysunozkan95@yahoo.com
authors.forename: A
authors.initials: A
authors.lastname: Ozkan
authors.forename: K
authors.initials: K
authors.lastname: Fiskin
mesh_terms: D000970:Antineoplastic Agents / Q000633:toxicity*; D001943:Breast Neoplasms / Q000201:enzymology / Q000473:pathology*; D002374:Catalase / Q000378:metabolism*; D045744:Cell Line, Tumor; D015251:Epirubicin / Q000633:toxicity*; D005260:Female; D005978:Glutathione / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D013482:Superoxide Dismutase / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; D015251:Epirubicin; D002374:Catalase; D013482:Superoxide Dismutase; D005982:Glutathione Transferase; D005978:Glutathione