title: Uranium (238U)-induced ROS and cell cycle perturbations, antioxidant responses and erythrocyte nuclear abnormalities in the freshwater iridescent shark fish Pangasius sutchi.
abstract: The strategic plan of this study is to analyze any possible radiological impact on aquatic organisms from forthcoming uranium mining facilities around the Nagarjuna Sagar Dam in the future. The predominantly consumed and dominant fish species Pangasius sutchi, which is available year-round at Nagarjuna Sagar Dam, was selected for the study. To comprehend the outcome and to understand the mode of action of238U, the fish species Pangasius sutchi was exposed to ¼ and ½ of the LC50doses of waterborne238U in a static system in duplicate for 21 days. Blood and organs, including the gills, liver, brain and muscles, were collected at different time periods-0h, 24h, 48h, 72h, 96h, 7, days 14days and 21 days-using ICP-MS to determine the toxic effects of uranium and the accumulation of238U concentrations. The bioaccumulation of238U in P. sutchi tissues was dependent on exposure time and concentration. The accumulation of uranium was, in order of magnitude, measured as gills>liver>brain>tissue, with the highest accumulation in the gills. It was observed that exposure to238U significantly reduced antioxidant enzymes such as superoxide dismutase, catalase, and lipid peroxidase. The analysis of DNA fragmentation by comet assay and cell viability by flow cytometry was performed at different time intervals. DNA histograms by flow cytometry analysis revealed an increase in the G2/M phase and the S phase. The long-term238U exposure studies in fish showed increasing micronucleus frequencies in erythrocytes with greater exposure time. The higher the concentration of238U is, the greater is the effect observed, suggesting a close relationship between accumulation and toxicity. A possible ROS-mediated238U toxicity mechanism and antioxidant responses have been proposed.
authors.affiliation: Center for Environmental Nuclear Research, Directorate of Research, SRM University, Kattankulathur, Chennai, Tamil Nadu, 603203, India.
authors.forename: Sathesh Kumar
authors.initials: SK
authors.lastname: Annamalai
authors.affiliation: Center for Environmental Nuclear Research, Directorate of Research, SRM University, Kattankulathur, Chennai, Tamil Nadu, 603203, India. Electronic address: kanthad.arunachalam@gmail.com.
authors.forename: Kantha Deivi
authors.initials: KD
authors.lastname: Arunachalam
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D002397:Catfishes / Q000378:metabolism*; D002453:Cell Cycle / Q000187:drug effects*; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism*; D020552:Comet Assay; D004249:DNA Damage; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D005434:Flow Cytometry; D005618:Fresh Water; D005880:Gills / Q000187:drug effects / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D015162:Micronucleus Tests; D009132:Muscles / Q000187:drug effects / Q000378:metabolism; D009153:Mutagens / Q000633:toxicity; D009928:Organ Specificity / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism; D014501:Uranium / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity; D014875:Water Pollutants, Radioactive / Q000633:toxicity
chemical_list: D000975:Antioxidants; D009153:Mutagens; D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; D014875:Water Pollutants, Radioactive; D014501:Uranium; D002374:Catalase; D013482:Superoxide Dismutase
keywords: Antioxidant responses and erythrocyte nuclear abnormalities; Cell cycle perturbations; Pangasius sutchi; Uranium