Bailey David, Finlayson Kimberly A, Dogruer Gulsah, Bennett William W, van de Merwe Jason P
Coastal and Marine Research Centre, Griffith University, Gold Coast, Queensland, Australia; Australian Rivers Institute, Griffith University, Queensland, Australia.
Coastal and Marine Research Centre, Griffith University, Gold Coast, Queensland, Australia; Australian Rivers Institute, Griffith University, Queensland, Australia.
Aquat Toxicol. 2023 Feb;255:106394. doi: 10.1016/j.aquatox.2023.106394. Epub 2023 Jan 2.
Cell-based toxicity testing has emerged as a useful tool in (eco)toxicological research, allowing the ethical assessment of the effects of contaminants such as trace metals on marine megafauna. However, metal interactions with various dissolved ligands in the microplate environment may influence the effective exposure concentrations. Hence, the cells are not exposed to the nominal concentrations within the test system. This study aimed to establish and evaluate the effectiveness of cell-based bioassays for investigating the toxicity of selected metals in dugongs through the following objectives: (1) measure the cytotoxic potential of cadmium (Cd), and chromium (Cr) to dugong skin cell cultures, (2) investigate the interactions between media constituents and selected trace metals in cell-based bioassays, and (3) evaluate the risk to a free-ranging population of dugong based on effect values. Chromium was the most toxic of the metals tested (EC = 1.14 µM), followed by Cd (EC = 6.35 µM). Assessment of ultrafiltered (< 3 kDa) exposure media showed that 1% and 92.5% of Cr and Cd were associated with larger organic components of the media. Further, the binding of Cd to media constituents was calculated to underestimate Cd toxicity in cell-based assays by an order of magnitude. This understanding of metal partitioning in cell-based bioassays provides a more accurate method for assessing toxicity in cell-based bioassays. In addition, this study illustrated that dugong cells are more sensitive to Cr and Cd than other marine wildlife species. The chemical risk assessment found the dugong population in Moreton Bay to be at high risk from Cd exposure.
基于细胞的毒性测试已成为（生态）毒理学研究中的一种有用工具，可对痕量金属等污染物对海洋大型动物的影响进行伦理评估。然而，金属在微孔板环境中与各种溶解配体的相互作用可能会影响有效暴露浓度。因此，细胞并未暴露于测试系统内的标称浓度。本研究旨在通过以下目标建立并评估基于细胞的生物测定法对儒艮体内选定金属毒性的研究效果：（1）测量镉（Cd）和铬（Cr）对儒艮皮肤细胞培养物的细胞毒性潜力，（2）研究基于细胞的生物测定中培养基成分与选定痕量金属之间的相互作用，以及（3）根据效应值评估自由放养儒艮种群所面临的风险。在所测试的金属中，铬的毒性最大（EC = 1.14 μM），其次是镉（EC = 6.35 μM）。对超滤（< 3 kDa）暴露培养基的评估表明，1%和92.5%的铬和镉与培养基中较大的有机成分相关。此外，经计算，在基于细胞的测定中，镉与培养基成分的结合会使镉毒性的评估低估一个数量级。这种对基于细胞的生物测定中金属分配的理解为评估基于细胞的生物测定中的毒性提供了一种更准确的方法。此外，本研究表明，儒艮细胞对铬和镉的敏感性高于其他海洋野生动物物种。化学风险评估发现，摩顿湾的儒艮种群因镉暴露而处于高风险状态。
