University of Bologna, Inter-Departmental Research Centre for Environmental Science (CIRSA), via S. Alberto 163, 48123 Ravenna, Italy.
University of Bologna, Department of Biological, Geological, and Environmental Sciences, via Selmi 3, 40100 Bologna, Italy; University of Bologna, Inter-Departmental Research Centre for Environmental Science (CIRSA), via S. Alberto 163, 48123 Ravenna, Italy.
Sci Total Environ. 2016 Sep 1;563-564:538-48. doi: 10.1016/j.scitotenv.2016.04.125. Epub 2016 May 4.
The occurrence of caffeine (CF), a biologically active drug, has widely been documented in coastal waters, and whether its environmental concentrations do represent a threat for marine organisms is unclear. The present study aimed at assessing sub-lethal effects induced by a 7-day exposure to environmentally relevant concentrations of CF (5, 50 and 500ng/L) in the Mediterranean mussel, Mytilus galloprovincialis. CF in water and mussel tissues, and a battery of biomarkers, including lysosomal parameters of general stress, oxidative stress responses and endpoints of neurological and genetic damages, were evaluated and tested for significance vs controls (p<0.05). CF exposure triggered a significant decrease of lysosomal membrane stability in both haemocytes and digestive gland (at 50 and 500ng/L CF) and a significant increase of lysosomal content of neutral lipids (at 500ng/L CF), indicating the onset of a stress syndrome. No effects were noted on lipid peroxidation parameters, such as malondialdehyde and lipofuscin content. The activity of the antioxidant enzymes glutathione S-transferase (GST) and catalase was unmodified in gills, while a significant increase of GST activity was observed in digestive gland (at 5 and 500ng/L CF), suggesting the occurrence of GST-mediated phase II detoxifying processes. CF did not induce geno/neurotoxicity, as shown by the lack of effects on primary DNA damages and acetylcholinesterase activity. In line with its high hydrophilicity, CF did not bioaccumulate in mussel tissues. Data were integrated using the Mussel Expert System, which assigned a low stress level to mussels exposed to 500ng/L CF, whereas no alterations of animal health status were highlighted at lower dosages. This study revealed a low profile of toxicity for environmental concentrations of CF, and confirmed the suitability of an integrated biomarker-based approach to provide a comprehensive picture of the degree of stress induced by emerging contaminants in marine invertebrates.
咖啡因（CF）是一种具有生物活性的药物，其在沿海水域中的存在已被广泛记录，但其环境浓度是否对海洋生物构成威胁尚不清楚。本研究旨在评估在环境相关浓度（5、50 和 500ng/L）的 CF 暴露 7 天后对地中海贻贝（Mytilus galloprovincialis）产生的亚致死效应。评估了水中和贻贝组织中的 CF 以及一系列生物标志物，包括一般应激的溶酶体参数、氧化应激反应以及神经和遗传损伤的终点，并且与对照组（p<0.05）进行了显著性测试。CF 暴露会导致血细胞和消化腺中的溶酶体膜稳定性显著降低（在 50 和 500ng/L 的 CF 下），并且中性脂质的溶酶体含量显著增加（在 500ng/L 的 CF 下），表明应激综合征的发生。未观察到脂质过氧化参数（如丙二醛和脂褐素含量）的变化。鳃中的谷胱甘肽 S-转移酶（GST）和过氧化氢酶的活性没有改变，而消化腺中的 GST 活性显著增加（在 5 和 500ng/L 的 CF 下），表明发生了 GST 介导的 II 期解毒过程。CF 没有诱导遗传/神经毒性，因为初级 DNA 损伤和乙酰胆碱酯酶活性没有变化。根据其高亲水性，CF 不会在贻贝组织中生物积累。数据使用贻贝专家系统进行了整合，该系统将暴露于 500ng/L CF 的贻贝评定为低应激水平，而在较低剂量下没有突出动物健康状况的变化。这项研究揭示了 CF 的环境浓度具有较低的毒性特征，并证实了基于综合生物标志物的方法适用于提供海洋无脊椎动物中新兴污染物引起的应激程度的综合情况。
