title: Radiation protection by Terminalia chebula: some mechanistic aspects.
abstract: Radioprotective ability of the aqueous extract of the fruit of Terminalia chebula (TCE) was evaluated for its antioxidant and radioprotective abilities. TCE (50 microg) was able to neutralise 1,1-diphenyl-2-picrylhydrazyl, a stable free radical by 92.9%. The free radical neutralizing ability of TCE was comparable to that of ascorbate (100 microM) 93.5% and gallic acid (100 microM) 91.5% and was higher than that of the diethyldithiocarbamate (200 microM) 55.4%, suggesting the free radical activity of TCE. TCE protected the plasmid DNA pBR322 from undergoing the radiation-induced strand breaks. Radiation damage converts the supercoiled form (ccc) of plasmid to open circular form (oc); the presence of TCE during radiation exposure protected the plasmid from undergoing these damages. The administration of TCE (80 mg/kg body weight, i.p.) prior to whole body irradiation of mice (4 Gy) resulted in a reduction of peroxidation of membrane lipids in the mice liver as well as a decrease in radiation-induced damage to DNA, as assayed by single-cell gel electrophoresis (comet assay). TCE also protected the human lymphocytes from undergoing the gamma radiation-induced damage to DNA exposed in vitro to 2 Gy gamma-radiation. These results suggest the radioprotective ability of TCE.
authors.affiliation: Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400 085, India.
authors.forename: Nitin Motilal
authors.initials: NM
authors.lastname: Gandhi
authors.forename: Cherupally Krishnan Krishnan
authors.initials: CK
authors.lastname: Nair
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D004249:DNA Damage; D005609:Free Radicals / Q000378:metabolism; D005720:Gamma Rays; D006801:Humans; D066298:In Vitro Techniques; D007962:Leukocytes / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D015227:Lipid Peroxidation / Q000187:drug effects / Q000528:radiation effects; D008297:Male; D051379:Mice; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D010936:Plant Extracts / Q000494:pharmacology; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D029766:Terminalia
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D010936:Plant Extracts; D011837:Radiation-Protective Agents