Faculty of Life Sciences, Department of Zoology, Aligarh Muslim University, Aligarh-202002, India.
Chemosphere. 2024 Sep;364:143045. doi: 10.1016/j.chemosphere.2024.143045. Epub 2024 Aug 8.
Synthetic dyes are the primary cause of water pollution in industrial regions. Azo dyes account for 60-70% of such dyes used in the textile sector due to their numerous beneficial characteristics. Nevertheless, there is a dearth of knowledge regarding the toxicity of Eriochrome Black T (EBT), a widely used azo dye in the textile industry. Therefore, the current study was designed to investigate the effect of EBT exposure on two catfish species, Heteropneustes fossilis and Clarias batrachus. Following 96 h exposure to 1, 10 and 20 mgL of EBT, the MDA content and activities of SOD, CAT and GR exhibited a rising trend. However, as the concentration of EBT increased in both species, GPx showed decreased activity. EBT exposure also altered gut morphometry as well as the three main digestive enzymes activity (increase in lipase and trypsin activity, while decrease in amylase activity). In addition, the exposure of EBT had a significant impact on the gut microbiota of both species. C. batrachus demonstrated the suppression or absence of beneficial gut commensals (Bacillus and Cetobacterium), whereas H. fossilis revealed the proliferation and appearance of beneficial commensal microbes (Bacillus, Bacteroides, Prevotella, and Megashaera). Furthermore, the expansion or absence of these microbial communities indicated that the gut microbiota of both species was involved in dye digestion, immunity and detoxification. Overall, the percent change calculation of all the selected biomarkers, together with gut microbiota analysis, indicates that C. batrachus was more vulnerable to EBT exposure than H. fossilis. The present investigation effectively demonstrated the toxic impact of EBT on fish health by employing oxidative stress markers, digestive enzymes, and the fish gut microbiota as a promising tool for screening the impact of dye exposure on digestive physiology in toxicological research.
合成染料是工业地区水污染的主要原因。偶氮染料因其众多有益特性，占纺织行业使用的此类染料的 60-70%。然而，由于缺乏对广泛用于纺织工业的偶氮染料 Eriochrome Black T (EBT) 的毒性的了解，因此目前的研究旨在研究 EBT 暴露对两种鲶鱼，Heteropneustes fossilis 和 Clarias batrachus 的影响。在 1、10 和 20 mgL 的 EBT 暴露 96 小时后，MDA 含量以及 SOD、CAT 和 GR 的活性呈上升趋势。然而，随着两种鱼类中 EBT 浓度的增加，GPx 的活性降低。EBT 暴露还改变了肠道形态以及三种主要消化酶的活性（脂肪酶和胰蛋白酶活性增加，而淀粉酶活性降低）。此外，EBT 的暴露对两种鱼类的肠道微生物群也有重大影响。C. batrachus 表现出有益肠道共生菌（芽孢杆菌和鲸杆菌）的抑制或缺失，而 H. fossilis 则表现出有益共生微生物（芽孢杆菌、拟杆菌、普雷沃氏菌和巨球菌）的增殖和出现。此外，这些微生物群落的扩张或缺失表明，两种鱼类的肠道微生物群都参与了染料消化、免疫和解毒。总体而言，所有选定生物标志物的百分比变化计算，加上肠道微生物群分析，表明 C. batrachus 比 H. fossilis 更容易受到 EBT 暴露的影响。本研究通过采用氧化应激标志物、消化酶和鱼类肠道微生物群作为一种有前途的工具来筛选染料暴露对毒理学研究中消化生理学的影响，有效地证明了 EBT 对鱼类健康的毒性影响。
