Background: Mitochondria are the cell’s powerhouse, the site where the vast majority of ATP is synthesized. Mitochondrial activity represent a central checkpoint for detection of the difference between cancer cells and normal cells at the metabolic profile.Objective: To find out if there is a correlation between in vitro transformation and mitochondrial activity, by measuring the activity during clonal evolution of the locally established rat embryo fibroblast (REF) cell line throughout studying different passages.Materials & Methods: The (REF) cell line, was in vitro cultured. Mitochondria were isolated by differential centrifugation following Mitochondria Isolation Kit. Enzymatic activity of intact mitochondria has been measured using Cytochrome C Oxidase Activity Assay Kit. The decrease in absorbance at 550nm as horse heart ferrocytochrome c was oxidized has been monitored.Results: Depending on the conducted colorimetric assay, cytochrome c oxidase activity was measured, for the three different passages (42, 72 and 91) of REF cell line. At 550 nm, spectral data were valued (0.247, 0.723 and 1.318) unit/ml for three passages of REF cells (42, 72 and 91) respectively.Conclusion: There was a significant relationship between the mitochondrial activity and the age (passage number) for these in vitro cultured cells. These variations probably due to the transformational events that have been occurred during long-term continuous subculture

This research was conducted to evaluate three main methods usually used to assess cellular DNA damage in genotoxicity assays. These methods were single cell gel electrophoresis (comet assay), micronucleus formation, and DNA fragmentation assay. Nanoparticles genotoxicity is a subject of compelling immediate action as a result of wide application of nanotechnology in many sectors which in contact with humane health. The mentioned methods were used to assess the genotoxicity of silver nanoparticles in vivo. Silver nanoparticles were synthesized by laser ablation of pure silver plate submerged in double distilled water. The synthesized nanosilver was characterized with UV-Visible spectroscopy and atomic force microscope. After its characterization, silver nanoparticles were injected subcutaneously in to BALB/c mice at 200 µg/ kg BW for two different periods of time, one week and two weeks in daily manner. After the end of injection the animals were sacrificed and their bone marrow cells, lymphocytes, and spleen cells were collected. DNA damage in these cells was assessed using the three mentioned methods. Results indicated that the three types of DNA damage assessment methods were capable to detect the genotoxicity of silver nanoparticles in the treated animals. Spleen cells were the less DNA damaged cells as indicated with the three assays in the first week of injection. Lymphocytes and bone marrow cells was effected in more aggressive manner.

The cytotoxic effect of zinc oxide nanoparticles against mice mammary adenocarcenoma cells wascarried out in vitro. The used nanoparticles were synthesized by pulsed laser ablation in liquidmethods; the used liquid was deionized water. Colloidal suspension of zinc oxide nanoparticles wassynthesized by Q-switched Nd: YAG pulse laser device (1064 nm) laser energy was 600 mJ and pulseduration was 10 nanosecond. High purity metallic zinc plate was submerged in 10 ml deionizedwater in 50 ml glass baker and ablated with 1000 pulse at room temperature. The nanospecificitiesof the synthesized nanoparticle colloidal were characterized with UV-Vis scanningspectrophotometer. Atomic force microscope was used to determine the particle size distribution andparticles shape. The ZnO crestless formation was characterized by X-ray diffraction.Mice mammary adenocarcenoma cells was treated with 25, 50, 100 ppm of ZnO nanoparticles.Results indicated a significant toxicity of the ZnO nanoparticles toward cancer cells, this toxicitycorrelated directly with ZnO nanoparticles elevated concentrations. These result need to be furtherinvestigated and the molecular mechanism of ZnO nanoparticles effect should be more clarify.