title: Roles of p53 and caspases in induction of apoptosis in MCF- 7 breast cancer cells treated with a methanolic extract of Nigella sativa seeds.
abstract: BACKGROUND
  Nigella Sativa (NS) is an herb from the Ranunculaceae family that exhibits numerous medicinal properties and has been used as important constituent of many complementary and alternative medicines (CAMs). The ability of NS to kill cancer cells such as PC3, HeLa and hepatoma cells is well established. However, our understanding of the mode of death caused by NS remains nebulous. The objective of this study was to gain further insight into the mode and mechanism of death caused by NS in breast cancer MCF-7 cells.
  
  
  METHODS
  Human breast cancer cells (MCF-7) were treated with a methanolic extract of NS, and a dose- and time-dependent study was performed. The IC50 was calculated using a Cell Titer Blue® viability assay assay, and evidence for DNA fragmentation was obtained by fluorescence microscopy TUNEL assay. Gene expression was also profiled for a number of apoptosis-related genes (Caspase-3, -8, -9 and p53 genes) through qPCR.
  
  
  RESULTS
  The IC50 of MCF-7 cells was 62.8 μL/mL. When MCF-7 cells were exposed to 50 μL/mL and 100 μL/mL NS for 24 h, 48 h and 72 h, microscopic examination (TUNEL assay) revealed a dose- and time-dependent increase in apoptosis. Similarly, the expression of the Caspase-3, -8, -9 and p53 genes increased significantly according to the dose and time.
  
  
  CONCLUSIONS
  NS induced apoptosis in MCF-7 cells through both the p53 and caspase pathways. NS could potentially represent an alternative source of medicine for breast cancer therapy.
authors.affiliation: Molecular Cancer Biology Research Lab, Dept. of Food Science and Nutrition, College of Food and Agricultural Sciences, King Saud University, Saudi Arabia E-mail : alialshatwi@gmail.com.
authors.forename: Mohammed I
authors.initials: MI
authors.lastname: Alhazmi
authors.forename: Tarique N
authors.initials: TN
authors.lastname: Hasan
authors.forename: Gowhar
authors.initials: G
authors.lastname: Shafi
authors.forename: Abdullah H
authors.initials: AH
authors.lastname: Al-Assaf
authors.forename: Mohammed A
authors.initials: MA
authors.lastname: Alfawaz
authors.forename: Ali A
authors.initials: AA
authors.lastname: Alshatwi
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics; D053148:Caspase 3 / Q000096:biosynthesis / Q000235:genetics; D053181:Caspase 8 / Q000096:biosynthesis / Q000235:genetics; D053453:Caspase 9 / Q000096:biosynthesis / Q000235:genetics; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D053938:DNA Fragmentation / Q000187:drug effects; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D061986:MCF-7 Cells; D031881:Nigella sativa / Q000378:metabolism*; D010936:Plant Extracts / Q000494:pharmacology*; D012639:Seeds / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D010936:Plant Extracts; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9