title: Nano-silymarin provides protection against γ-radiation-induced oxidative stress in cultured human embryonic kidney cells.
abstract: Radiation can produce biological damage, mainly oxidative stress, via production of free radicals, including reactive oxygen species (ROS). Nanoparticles are of interest as radioprotective agents, particularly due to their high solubility and bioavailability. Silymarin is a hepatoprotective agent but has poor oral bioavailability. Silymarin was formulated as a nanoemulsion with the aim of improving its bioavailability and therapeutic efficacy. In the present study, we evaluated self-nanoemulsifying drug delivery systems (SNEDDS) formulated with surfactants and co-surfactants. Nano-silymarin was characterized by estimating % transmittance, globule size, and polydispersity index, and by transmission electron microscopy (TEM). The nano-silymarin obtained was in the range of 3-8nm diameter. With regard to DNA damage, measured by a plasmid relaxation assay, maximum protection was obtained at 10μg/mL. Cytotoxicity of nano-silymarin to human embryonic kidney (HEK) cells was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. Protective efficacy against γ-radiation was assessed by reduction in micronucleus frequency and ROS generation, using the 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA) assay. Radiation-induced apoptosis was estimated by microscopic analysis and cell-cycle estimation. Nano-silymarin was radioprotective, supporting the possibility of developing new approaches to radiation protection via nanotechnology.
authors.affiliation: Radiation Biotechnology Group, Division of Radiation Biosciences, Institute of Nuclear Medicine and Allied Sciences, Defence Research and Development Organisation, Brig SK Mazumdar Marg, Delhi 110054, India.
authors.forename: Manish
authors.initials: M
authors.lastname: Adhikari
authors.affiliation: Radiation Biotechnology Group, Division of Radiation Biosciences, Institute of Nuclear Medicine and Allied Sciences, Defence Research and Development Organisation, Brig SK Mazumdar Marg, Delhi 110054, India; Office of the Director General-Life Sciences and Distinguished Scientist, DRDO Head Quarters, DRDO Bhawan, Rajaji Marg, New Delhi 110011, India. Electronic address: rajesharoradr@gmail.com.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Arora
mesh_terms: D002453:Cell Cycle / Q000187:drug effects; D004247:DNA / Q000737:chemistry; D004278:DNA, Superhelical / Q000737:chemistry; D005609:Free Radicals; D005720:Gamma Rays; D057809:HEK293 Cells; D006801:Humans; D015162:Micronucleus Tests; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry*; D018384:Oxidative Stress; D010316:Particle Size; D010957:Plasmids / Q000378:metabolism; D011837:Radiation-Protective Agents / Q000737:chemistry; D012838:Silymarin / Q000737:chemistry*; D018675:Toxicity Tests
chemical_list: D004278:DNA, Superhelical; D005609:Free Radicals; D011837:Radiation-Protective Agents; D012838:Silymarin; D004247:DNA
keywords: Flow cytometry; HEK cells; Nano-silymarin; Reactive oxygen species; γ-Irradiation