In the present study, a multi-biomarker approach was used to assess the biological effects of metal pollution in the southern lagoon of Tunis, on clam Ruditapes decussatus both in "hot" (in summer) and "cold" (in winter) seasons. Clams were collected in August 2015 and February 2016 from three sites of the lagoon and from Louza considered a reference site. The concentrations of five trace metals (cadmium, copper, iron, lead, and zinc) in the soft tissues of R. decussatus were evaluated at the sampling sites. A core of biomarkers indicative of (a) neurotoxicity (acetylcholinesterase, AChE); (b) biotransformation (glutathione S-transferase, GST); (c) oxidative stress (catalase, CAT; total glutathione peroxidase, T-GPx; total glutathione peroxidase, T-GPx; selenium-dependent glutathione peroxidase, Se-GPx; glutathione reductase, GR; superoxide dismutase, SOD) (d) lipid peroxidation (malondialdhyde, MDA level), and (e) apoptotic process (caspase 3-like, CSP3) was selected for measurements of environmental effects on the populations of clams collected from the different sampling sites. The results of metal bioaccumulation in soft tissues of Ruditapes decussatus revealed a high pollution in the South Lagoon of Tunis with spatial variation and relatively high levels at the navigation channel. Anthropogenic pollutants in the lagoon led to the activation of antioxidant defense and biotransformation enzymes to oxidative damage of the membrane and activation of apoptosis, and revealed neurotoxicity. Among this core of biomarkers, the antioxidants enzymes (CAT, SOD, GR, and GPx) were very sensitive, allowing the discrimination among sites and pointing to the navigation channel as the most impacted site in the southern lagoon of Tunis. Moreover, a significant effect of season was recorded on biomarkers responses (e.g., CAT, GR, SOD, AChE, and CSP3 activities and MDA levels) with higher levels in winter than in summer, probably influenced by the reproductive stage and food availability. Finally, the measurement of the selected core of biomarkers in the whole soft tissues of clams was considered as an integrated indicator of environmental stress. Moreover, R. decussatus proved to be a remarkable sentinel species capable to establish a reliable diagnosis of the health status of the marine environment in different areas of the southern lagoon of Tunis, both in "hot" and "cold" seasons.

中文翻译：

---

暴露于污染场所的蛤Ru的氧化应激和破坏生物标志物：炎热和寒冷季节的可靠生物监测工具。

在本研究中，在“炎热”季节（夏季）和“寒冷”季节（冬季），突尼斯南部泻湖中的金属污染对蛤仔Ruditapes decussatus的生物影响均采用了多种生物标记方法。2015年8月和2016年2月，从泻湖的三个地点和被认为是参考地点的Louza收集了蛤。在采样点评估了德氏红soft软组织中五种微量金属（镉，铜，铁，铅和锌）的浓度。指示（a）神经毒性（乙酰胆碱酯酶，AChE）的生物标志物的核心；（b）生物转化（谷胱甘肽S-转移酶，GST）；（c）氧化应激（过氧化氢酶，CAT；总谷胱甘肽过氧化物酶，T-GPx；总谷胱甘肽过氧化物酶，T-GPx；硒依赖性谷胱甘肽过氧化物酶，Se-GPx；谷胱甘肽还原酶，GR; 选择超氧化物歧化酶（SOD）（d）脂质过氧化（丙二醛，丙二醛（MDA）水平）和（e）凋亡过程（半胱天冬酶3-样，CSP3）来衡量环境对从不同采样地点收集的蛤类种群的影响。Ruditapes decussatus的软组织中金属生物富集的结果表明，突尼斯南部泻湖的污染高度，空间变化较大，导航通道的污染水平较高。泻湖中的人为污染物导致抗氧化剂防御和生物转化酶的活化，从而导致膜的氧化损伤和细胞凋亡的活化，并显示出神经毒性。在这一生物标志物的核心中，抗氧化剂酶（CAT，SOD，GR和GPx）非常敏感，允许在站点之间进行区分，并指出导航通道是突尼斯南部泻湖中受影响最大的站点。此外，季节对生物标志物响应（例如CAT，GR，SOD，AChE和CSP3活性和MDA水平）的记录显着影响，冬季水平高于夏季，这可能受生殖阶段和食物供应量的影响。最后，对蛤的整个软组织中选定的生物标志物核心的测量被认为是环境压力的综合指标。此外，事实证明，在“炎热”和“寒冷”季节，R。decussatus是一种出色的定点物种，能够对突尼斯南部泻湖不同地区的海洋环境健康状况做出可靠的诊断。