title: In vitro evaluation of antioxidant and radioprotective properties of a novel extremophile from mud volcano: implications for management of radiation emergencies.
abstract: A thermophilic bacterium, designated as RH 127, was isolated from mud volcano (Baratang Islands) of Andaman region, India (12°07'N 92°47'E/12.117°N 92.783°E) for the first time. Biochemical tests and 16S rRNA gene sequencing indicate that it belongs to the genus Geobacillus. The strain showed 98% confirmed 16S rRNA gene sequence homology with Geobacillus toebii. The bacteria was extracted in various solvent systems and three different fractions prepared. In the present study, antioxidant and radioprotective activity of extracts (INM-7860, INM-7861, and INM-7862) of bacterium G. toebii (strain RH 127) were evaluated. The fractions were evaluated for their introspective comparison of the relative antioxidant efficiency. The antioxidative activities, DPPH radical scavenging effects, hydroxyl radical scavenging effects, membrane protection, antihemolytic activity, and linoleic acid degradation efficacies were assayed. INM-7861 and INM-7862 activated NF-κB expression, as evidenced by reporter assay studies, and thereby contributed to overall radioprotective effect. INM-7862 exhibited best results. This study explicitly shows that the extracts of G. toebii have immense potential as a radiation countermeasure agent.
authors.affiliation: Radiation Biotechnology Group, Institute of Nuclear Medicine and Allied Sciences (Defence Research and Development Organization; DRDO), Brig S. K. Mazumdar Marg, Delhi 110054, India.
authors.forename: Atlar Singh
authors.initials: AS
authors.lastname: Dhaker
authors.forename: Rohit
authors.initials: R
authors.lastname: Marwah
authors.forename: Rakesh
authors.initials: R
authors.lastname: Damodar
authors.forename: Damodar
authors.initials: D
authors.lastname: Gupta
authors.forename: Hemant Kumar
authors.initials: HK
authors.lastname: Gautam
authors.forename: Sarwat
authors.initials: S
authors.lastname: Sultana
authors.forename: Rajesh
authors.initials: R
authors.lastname: Arora
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology; D001713:Biphenyl Compounds / Q000378:metabolism; D004269:DNA, Bacterial / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D004638:Emergency Treatment / Q000379:methods; D016166:Free Radical Scavengers / Q000737:chemistry / Q000494:pharmacology; D056506:Geobacillus / Q000737:chemistry* / Q000145:classification / Q000235:genetics; D057809:HEK293 Cells; D006461:Hemolysis / Q000187:drug effects / Q000528:radiation effects; D006801:Humans; D017665:Hydroxyl Radical / Q000037:antagonists & inhibitors / Q000378:metabolism; D007194:India; D015227:Lipid Peroxidation / Q000187:drug effects / Q000528:radiation effects; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D010802:Phylogeny; D010851:Picrates / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D011832:Radiation Injuries / Q000517:prevention & control; D011837:Radiation-Protective Agents / Q000737:chemistry* / Q000494:pharmacology; D017422:Sequence Analysis, DNA; D018707:Volcanic Eruptions
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D004269:DNA, Bacterial; D016166:Free Radical Scavengers; D016328:NF-kappa B; D010851:Picrates; D012336:RNA, Ribosomal, 16S; D011837:Radiation-Protective Agents; D017665:Hydroxyl Radical; C004931:1,1-diphenyl-2-picrylhydrazyl