Laboratory of Biochemistry and Environmental Toxicology, 4040, Higher Institute of Agronomy, Chott-Mariem, Tunisia; Department of Biological Sciences, Faculty of Science of Tunis, University of Tunis El Manar, Tunis, Tunisia.
Laboratory of Biochemistry and Environmental Toxicology, 4040, Higher Institute of Agronomy, Chott-Mariem, Tunisia.
Environ Pollut. 2020 Oct;265(Pt A):114831. doi: 10.1016/j.envpol.2020.114831. Epub 2020 May 20.
Mining activity may cause heavy metal accumulation, which threatens human and animal health by their long-term persistence in the environment. This study aims to assess the impact of polymetallic pollution on chicken (Gallus domesticus) from old lead mining sites in northeast of Tunisia: Jebel Ressas (JR). Samples of soil and chickens were collected from five sites being ranked along a gradient of heavy metal contamination. Heavy metal loads were evaluated in soil samples and in chicken liver and kidney. Biochemical evaluation of oxidative stress parameters termed as Catalase (CAT), Glutathione-S-Transferase (GST), and Malondialdehydes (MDA) accumulation was monitored. Metallothionein protein level was assessed as a specific response to heavy metals. DNA alteration was achieved using MNi frequency in the investigated tissues. Finally, the evaluation of gene expression levels of CAT, GST, mt1, mt4, P53, bcl2, caspase3 and DNA-ligase was performed. Our data showed the highest loads of Cd, Cu, Zn and Pb in tissues of animals from site 3, being more pronounced in kidney. Biochemical data suggested a significant increase in antioxidant enzymes activities in all sites respect to control except in site 3 were CAT and GST were inhibited. DNA alteration was observed in all tissues being very pronounced in animals from site 3. Overall, transcriptomic data showed that genes involved in apoptosis were up-regulated in animals exposed to the most contaminated soils. Our data suggest that chicken and selected biomarkers offer a suitable model for biomonitoring assessment of heavy metals transfer through the food web in mining sites. Finally, the obtained results of heavy metals accumulation and related alterations should be carefully considered in view of the controversial relationship between distribution and toxicology of contaminants in exposed organisms.
采矿活动可能导致重金属积累，这些重金属在环境中长期存在，威胁着人类和动物的健康。本研究旨在评估突尼斯东北部旧铅矿开采区（Jebel Ressas，JR）多金属污染对鸡（Gallus domesticus）的影响：从沿重金属污染梯度排列的五个地点采集土壤和鸡样本。评估土壤样本和鸡肝、肾中的重金属负荷。监测作为氧化应激参数的过氧化氢酶（CAT）、谷胱甘肽-S-转移酶（GST）和丙二醛（MDA）积累的生化评估。金属硫蛋白蛋白水平作为对重金属的特定反应进行评估。使用 MNi 频率在研究组织中评估 DNA 改变。最后，评估 CAT、GST、mt1、mt4、P53、bcl2、caspase3 和 DNA 连接酶的基因表达水平。我们的数据显示，3 号地点动物组织中 Cd、Cu、Zn 和 Pb 的含量最高，在肾脏中更为明显。生化数据表明，除 3 号地点外，所有地点的抗氧化酶活性均显著高于对照，在该地点 CAT 和 GST 受到抑制。所有组织均观察到 DNA 改变，3 号地点的动物最为明显。总的来说，转录组数据表明，暴露于污染最严重土壤的动物中，参与细胞凋亡的基因上调。我们的数据表明，鸡和选定的生物标志物为通过食物链在矿区进行重金属转移的生物监测评估提供了合适的模型。最后，鉴于暴露生物体内污染物的分布和毒理学之间存在争议关系，应仔细考虑重金属积累和相关改变的结果。
