title: Cadmium and copper toxicity in three marine macroalgae: evaluation of the biochemical responses and DNA damage.
abstract: Marine macroalgae have evolved a different mechanism to maintain physiological concentrations of essential metal ions and non-essential metals. The objective of the present work was to evaluate the antioxidant response and DNA damage of copper and cadmium ions in three halophytes, namely, Acanthophora spicifera, Chaetomorpha antennina, and Ulva reticulata. Accumulation of copper was significantly higher (P < 0.05) than that of cadmium. Biochemical responses showed that copper was considerably more toxic than cadmium (P < 0.05). Decreases in glutathione content and fluctuations of super oxide dismutase, catalase, and glutathione peroxidase activities were observed corresponding to time and concentration of exposure. Interestingly, it was also observed that antioxidant levels decreased as a result of metal accumulation, which may be due to free radicals generated by copper and cadmium in seaweeds. The present study also showed that copper and cadmium increased oxidative stress and induced antioxidant defense systems against reactive oxygen species. The order of toxicity for metals in the studied seaweeds was U. reticulata > A. spicifera > C. antennina. DNA damage index analysis supported that copper was significantly (P < 0.05) more toxic than cadmium. Bioaccumulation, biochemical responses, and DNA damage observed in the here analyzed marine macroalgae after exposure to selected metals indicate that these marine organisms represent useful bioindicators of marine pollution.
authors.affiliation: Department of Marine and Coastal Studies, School of Energy, Environment and Natural Resources, Madurai Kamaraj University, Madurai, 625021, Tamilnadu, India.
authors.forename: M Yokesh
authors.initials: MY
authors.lastname: Babu
authors.forename: L
authors.initials: L
authors.lastname: Palanikumar
authors.forename: N
authors.initials: N
authors.lastname: Nagarani
authors.forename: V Janaki
authors.initials: VJ
authors.lastname: Devi
authors.forename: S Ramesh
authors.initials: SR
authors.lastname: Kumar
authors.forename: C M
authors.initials: CM
authors.lastname: Ramakritinan
authors.forename: A K
authors.initials: AK
authors.lastname: Kumaraguru
mesh_terms: D000975:Antioxidants; D002104:Cadmium / Q000737:chemistry* / Q000633:toxicity*; D002374:Catalase / Q000378:metabolism; D003300:Copper / Q000737:chemistry* / Q000633:toxicity*; D004249:DNA Damage; D005609:Free Radicals; D005978:Glutathione / Q000378:metabolism; D008670:Metals / Q000737:chemistry / Q000633:toxicity; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D017382:Reactive Oxygen Species; D012624:Seaweed / Q000187:drug effects*; D013482:Superoxide Dismutase / Q000378:metabolism; D044445:Ulva / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D008670:Metals; D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; D002104:Cadmium; D003300:Copper; D002374:Catalase; D013482:Superoxide Dismutase; D005978:Glutathione