title: Protection of DNA and membrane from gamma radiation induced damage by gallic acid.
abstract: Gallic acid (3,4,5-trihydroxybenzoic acid, GA) is a naturally occurring plant phenol. In vitro and in vivo studies have shown that this phytochemical protected DNA and membranes against ionizing radiation. Rat liver microsomes and plasmid pBR322 DNA were exposed to various doses of gamma radiation in presence and absence of GA. Exposure of the microsomes to gamma radiation resulted in the formation of peroxides of membrane lipids measured as thiobarbituric acid reactive substances and presence of GA during irradiation prevented the formation of lipid peroxidation. Gamma irradiation of plasmid DNA resulted in induction of strand breaks in DNA resulting in disappearance of the supercoiled (ccc) form. Presence of GA during irradiation protected the DNA from undergoing the strand breaks. In in vivo studies it was found that whole body exposure of mice to gamma radiation (4 Gy) increased the formation of lipid peroxides in various tissues and damage to cellular DNA (as measured by alkaline comet assay) in peripheral blood leucocytes. Administration of GA to mice prior to whole body radiation exposure reduced the peroxidation of lipids and the damage to the cellular DNA indicating in vivo radiation protection of membranes and DNA by GA.
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; D020552:Comet Assay; D004247:DNA / Q000378:metabolism / Q000528:radiation effects*; D004305:Dose-Response Relationship, Drug; D005419:Flavonoids / Q000037:antagonists & inhibitors / Q000378:metabolism; D005707:Gallic Acid / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D007928:Lethal Dose 50; D015227:Lipid Peroxidation / Q000528:radiation effects; D008054:Lipid Peroxides / Q000378:metabolism; D008566:Membranes / Q000378:metabolism / Q000528:radiation effects*; D051379:Mice; D008861:Microsomes / Q000378:metabolism / Q000528:radiation effects; D010636:Phenols / Q000037:antagonists & inhibitors / Q000378:metabolism; D059808:Polyphenols; D051381:Rats; D013045:Species Specificity; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D005419:Flavonoids; D008054:Lipid Peroxides; D010636:Phenols; D059808:Polyphenols; D017392:Thiobarbituric Acid Reactive Substances; D005707:Gallic Acid; D004247:DNA