title: Induction of Apoptosis by Green Synthesized Gold Nanoparticles Through Activation of Caspase-3 and 9 in Human Cervical Cancer Cells.
abstract: BACKGROUND
  Gold Nanoparticles (GNPs) are used in imaging and molecular diagnostic applications. As the development of a novel approach in the green synthesis of metal nanoparticles is of great importance and a necessity, a simple and safe method for the synthesis of GNPs using plant extracts of Zataria multiflora leaves was applied in this study and the results on GNPs' anticancer activity against HeLa cells were reported.
  
  
  METHODS
  The GNPs were characterized by UV-visible spectroscopy, FTIR, TEM, DLS and Zeta-potential measurements. In addition, the cellular up-take of nanoparticles was investigated using Dark Field Microscopy (DFM). Induction of apoptosis by high dose of GNPs in HeLa cells was assessed by MTT assay, Acridin orange, DAPI staining, Annexin V/PI double-labeling flow cytometry and caspase activity assay.
  
  
  RESULTS
  UV-visible spectroscopy results showed a surface plasmon resonance band for GNPs at 530 nm. FTIR results demonstrated an interaction between plant extract and nanoparticles. TEM images revealed different shapes for GNPs and DLS results indicated that the GNPs range in size from 10 to 42 nm. The Zeta potential values of the synthesized GNPs were between 30 to 50 Mev, indicating the formation of stable particles. As evidenced by MTT assay, GNPs inhibit proliferation of HeLa cells in dose-dependent GNPs and cytotoxicity of GNPs in Bone Marrow Mesenchymal Stem Cell (BMSCs) was lower than cancerous cells. At nontoxic concentrations, the cellular up-take of the nanoparticles took place. Acridin orange and DAPI staining showed morphological changes in the cell's nucleus due to apoptosis. Finally, caspase activity assay demonstrated HeLa cell's apoptosis through caspase activation.
  
  
  CONCLUSIONS
  The results showed that GNPs have the ability to induce apoptosis in HeLa cells.
authors.affiliation: Animal Developmental Biology, Research Center for Animal Development Applied Biology and Department of Biology, Mashhad Branch, Islamic Azad University, Mashhad, Iran.
authors.forename: Javad
authors.initials: J
authors.lastname: Baharara
authors.affiliation: Department of Animal Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran.
authors.forename: Tayebe
authors.initials: T
authors.lastname: Ramezani
authors.affiliation: Department of Cell and Molecular Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran.
authors.forename: Adeleh
authors.initials: A
authors.lastname: Divsalar
authors.affiliation: Animal Developmental Biology, Research Center for Animal Development Applied Biology and Department of Biology, Mashhad Branch, Islamic Azad University, Mashhad, Iran.
authors.forename: Marzieh
authors.initials: M
authors.lastname: Mousavi
authors.affiliation: Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
authors.forename: Arefeh
authors.initials: A
authors.lastname: Seyedarabi
keywords: Biosynthesis; Caspase; Gold nanoparticles; HeLa cells; Zataria multiflora