Babu M Yokesh, Palanikumar L, Nagarani N, Devi V Janaki, Kumar S Ramesh, Ramakritinan C M, Kumaraguru A K
Department of Marine and Coastal Studies, School of Energy, Environment and Natural Resources, Madurai Kamaraj University, Madurai, 625021, Tamilnadu, India.
Environ Sci Pollut Res Int. 2014;21(16):9604-16. doi: 10.1007/s11356-014-2999-0. Epub 2014 May 27.
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.
海洋大型藻类进化出了一种不同的机制来维持必需金属离子和非必需金属的生理浓度。本研究的目的是评估铜离子和镉离子对三种盐生植物，即刺松藻、触角刚毛藻和网胰藻的抗氧化反应和DNA损伤。铜的积累量显著高于镉（P < 0.05）。生化反应表明，铜的毒性比镉大得多（P < 0.05）。观察到谷胱甘肽含量的降低以及超氧化物歧化酶、过氧化氢酶和谷胱甘肽过氧化物酶活性随暴露时间和浓度的波动。有趣的是，还观察到抗氧化水平因金属积累而降低，这可能是由于海藻中铜和镉产生的自由基所致。本研究还表明，铜和镉增加了氧化应激，并诱导了针对活性氧的抗氧化防御系统。在所研究的海藻中，金属的毒性顺序为网胰藻 > 刺松藻 > 触角刚毛藻。DNA损伤指数分析支持铜的毒性显著高于镉（P < 0.05）。在暴露于选定金属后，在此分析的海洋大型藻类中观察到的生物积累、生化反应和DNA损伤表明，这些海洋生物是海洋污染的有用生物指标。
