Biology Department & CESAM, University of Aveiro, 3810-193, Aveiro, Portugal.
Chemistry Department & CESAM, University of Aveiro, 3810-193, Aveiro, Portugal.
Aquat Toxicol. 2021 Jan;230:105673. doi: 10.1016/j.aquatox.2020.105673. Epub 2020 Nov 2.
The negative effects induced in marine organisms by Climate Change related abiotic factors consequences, namely ocean warming, are well-known. However, few works studied the combined impacts of ocean warming and contaminants, as pharmaceutical drugs. Carbamazepine (CBZ) and cetirizine (CTZ) occur in the marine environment, showing negative effects in marine organisms. This study aimed to evaluate the impacts of ocean warming on the effects of CBZ and CTZ, when acting individually and combined (drug vs drug), in the edible clam Ruditapes philippinarum. For that, drugs concentration, bioconcentration factors and biochemical parameters, related with clam's metabolic capacity and oxidative stress, were evaluated after 28 days exposure to environmentally relevant scenarios of these stressors. The results showed limited impacts of the drugs (single and combined) at control and warming condition. Indeed, it appeared that warming improved the oxidative status of contaminated clams (higher reduced to oxidized glutathione ratio, lower lipid peroxidation and protein carbonylation levels), especially when both drugs were combined. This may result from clam's defence mechanisms activation and reduced metabolic capacity that, respectively, increased elimination and limited production of reactive oxygen species. At low stress levels, defence mechanisms were not activated which resulted into oxidative stress. The present findings highlighted that under higher stress levels clams may be able to activate defence strategies that were sufficient to avoid cellular damages and loss of redox homeostasis. Nevertheless, low concentrations were tested in the present study and the observed responses may greatly change under increased pollution levels or temperatures. Further research on this topic is needed since marine heat waves are increasing in frequency and intensity and pollution levels of some pharmaceuticals are also increasing in coastal systems.
气候变化相关非生物因素（如海洋变暖）对海洋生物产生的负面影响是众所周知的。然而，很少有研究关注海洋变暖与污染物（如药物）的联合影响。卡马西平（CBZ）和西替利嗪（CTZ）存在于海洋环境中，对海洋生物具有负面影响。本研究旨在评估海洋变暖对 CBZ 和 CTZ 单独和联合作用（药物与药物）时对菲律宾蛤仔（Ruditapes philippinarum）的影响。为此，在 28 天的暴露于这些胁迫因素的环境相关场景中，评估了药物浓度、生物浓缩因子和与蛤仔代谢能力和氧化应激相关的生化参数。结果表明，在对照和变暖条件下，药物（单独和联合）的影响有限。实际上，变暖似乎改善了受污染蛤仔的氧化状态（更高的还原型对氧化型谷胱甘肽比、更低的脂质过氧化和蛋白质羰基化水平），尤其是当两种药物联合使用时。这可能是由于蛤仔防御机制的激活和代谢能力的降低，分别增加了活性氧的消除和限制了其产生。在低胁迫水平下，防御机制未被激活，导致氧化应激。本研究结果强调，在较高胁迫水平下，蛤仔可能能够激活防御策略，从而避免细胞损伤和氧化还原稳态的丧失。然而，本研究仅测试了低浓度，在污染水平或温度升高的情况下，观察到的反应可能会发生很大变化。由于海洋热浪的频率和强度增加，以及一些药物的污染水平也在沿海系统中增加，因此需要进一步研究这一课题。
