title: Studies on the aqueous extract of Terminalia chebula as a potent antioxidant and a probable radioprotector.
abstract: Aqueous extract of a natural herb, Terminalia chebula was tested for potential antioxidant activity by examining its ability to inhibit gamma-radiation-induced lipid peroxidation in rat liver microsomes and damage to superoxide dismutase enzyme in rat liver mitochondria. The antimutagenic activity of the extract has been examined by following the inhibition of gamma-radiation-induced strand breaks formation in plasmid pBR322 DNA. In order to understand the phytochemicals responsible for this, HPLC analysis of the extract was carried out, which showed the presence of compounds such as ascorbate, gallic acid and ellagic acid. This was also confirmed by cyclic voltammetry. The extract inhibits xanthine/xanthine oxidase activity and is also an excellent scavenger of DPPH radicals. The rate at which the extract and its constituents scavenge the DPPH radical was studied by using stopped-flow kinetic spectrometer. Based on all these results it is concluded that the aqueous extract of T. chebula acts as a potent antioxidant and since it is able to protect cellular organelles from the radiation-induced damage, it may be considered as a probable radioprotector.
authors.affiliation: Radiation Chemistry and Chemical Dynamics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
authors.forename: G H
authors.initials: GH
authors.lastname: Naik
authors.forename: K I
authors.initials: KI
authors.lastname: Priyadarsini
authors.forename: D B
authors.initials: DB
authors.lastname: Naik
authors.forename: R
authors.initials: R
authors.lastname: Gangabhagirathi
authors.forename: H
authors.initials: H
authors.lastname: Mohan
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D001713:Biphenyl Compounds; D004305:Dose-Response Relationship, Drug; D005638:Fruit; D005720:Gamma Rays / Q000009:adverse effects; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000528:radiation effects; D008930:Mitochondria, Liver / Q000187:drug effects; D008517:Phytotherapy; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D011832:Radiation Injuries / Q000517:prevention & control*; D011837:Radiation-Protective Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar; D029766:Terminalia
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D010851:Picrates; D010936:Plant Extracts; D011837:Radiation-Protective Agents; C004931:1,1-diphenyl-2-picrylhydrazyl