title: Modulation of doxorubicin cytotoxicity by resveratrol in a human breast cancer cell line.
abstract: BACKGROUND
  Breast cancer is the most common cancer in the Arab world and it ranked first among Saudi females. Doxorubicin (DOX), an anthracycline antibiotic is one of the most effective anticancer agents used to treat breast cancer. chronic cardiotoxicity is a major limiting factor of the use of doxorubicin. Therefore, our study was designed to assess the role of a natural product resveratrol (RSVL) on sensitization of human breast cancer cells (MCF-7) to the action of DOX in an attempt to minimize doxorubicin effective dose and thereby its side effects.
  
  
  METHODS
  Human breast cancer cell line MCF-7, was used in this study. Cytotoxic activity of DOX was determined using (sulforhodamine) SRB method. Apoptotic cells were quantified after treatment by annexin V-FITC- propidium iodide (PI) double staining using flow-cytometer. Cell cycle disturbance and doxorubicin uptake were determined after RSVL or DOX treatment.
  
  
  RESULTS
  Treatment of MCF-7 cells with 15 μg/ml RSVL either simultaneously or 24 h before DOX increased the cytotoxicity of DOX, with IC50 were 0.056 and 0.035 μg/ml, respectively compared to DOX alone IC50 (0.417 μg/ml). Moreover, flow cytometric analysis of the MCF-7 cells treated simultaneously with DOX (0.5 μg/ml) and RSVL showed enhanced arrest of the cells in G0 (80%). On the other hand, when RSVL is given 24 h before DOX although there was more increased in the cytotoxic effect of DOX against the growth of the cells, however, there was decreased in percentage arrest of cells in G0, less inhibition of DOX-induced apoptosis and reduced DOX cellular uptake into the cells.
  
  
  CONCLUSIONS
  RSVL treatment increased the cytotoxic activity of DOX against the growth of human breast cancer cells when given either simultaneously or 24 h before DOX.
authors.affiliation: Department of Pharmacology, Faculty of Medicine, King Abdul-Aziz University, Jeddah, Saudi Arabia. moneimosman@hotmail.com.
authors.forename: Abdel-Moneim M
authors.initials: AM
authors.lastname: Osman
authors.forename: Hadeel M
authors.initials: HM
authors.lastname: Bayoumi
authors.forename: Sameer E
authors.initials: SE
authors.lastname: Al-Harthi
authors.forename: Zoheir A
authors.initials: ZA
authors.lastname: Damanhouri
authors.forename: Mohamed F
authors.initials: MF
authors.lastname: Elshal