Among toxic pollutants, Mercury (Hg) is a toxic heavy metal that induces harmful impacts on aquatic ecosystems directly and human being's health indirectly. This study confirmed the in vitro magnetic potential of magnetite Nano-Particles (Fe₃O₄ NPs) against waterborne Hg exposure-induced toxicity in Nile tilapia (Oreochromis niloticus). We further evaluate the safety profile of Fe₃O₄ NPs on fish growth, hemato-biochemical, histological parameters, bioaccumulation in muscles, and economy. Magnetite nanoparticles were characterized, adsorption loading to Hg ions was investigated, and testing different concentrations of Fe₃O₄ NPs (0.2, 0.4, 0.6, 0.8, and 1.0 mg/L) was applied to determine the highest concentration of adsorption. An in vivo experiment includes 120 fish with an average weight of 26.2 ± 0.26 g were randomly divided into 4 equal groups, each group had three replicates (n = 30 fish/group; 10 fish/ replicate). All groups were fed on a reference basal diet and the experiment was conducted for 30 days. The first group (G₁) was allocated as a control. The second group (G₂) received 1.0 mg/L aqueous suspension of Fe₃O₄ NPs. The third group (G₃) was exposed to an aqueous solution of Hg ions at a concentration of 0.025 mg/L. Meanwhile, the fourth group (G₄) acquired an aqueous suspension composed of a mixture of Hg ions and Fe₃O₄ NPs as previously mentioned. Throughout the exposure period, the clinical signs, symptoms, and mortalities were recorded. The Hg ions-exposed group induced the following consequences; reduced appetite resulting in reduced growth and less economic efficiency; microcytic hypochromic anemia, leukocytosis, lymphopenia, and neutrophilia; sharp and clear depletion in the immune indicators including lysozymes activity, immunoglobulin M (IgM), and Myeloperoxidase activities (MPO); significant higher levels of ALT, AST, urea, creatinine, and Superoxide dismutase (SOD); histological alterations of gill, hepatic and muscular tissues with strong expression of apoptotic marker (caspase 3); and a higher accumulation of Hg ions in the muscles. Surprisingly, Fe₃O₄ NPs-supplemented groups exhibited strong adsorption capacity against the Hg ions and mostly removed the Hg ions accumulation in the muscles. Also, the hematological, biochemical, and histological parameters were recovered. Thus, in order to assess the antitoxic role of Fe₃O₄ NPs against Hg and their safety on O. niloticus, and fill the gap of the research, the current context was investigated to evaluate the promising role of Fe₃O₄ NPs to prevent Hg-exposure-induced toxicity and protection of fish health, which ascertains essentiality for sustainable development of nanotechnology in the aquatic environment.

在有毒污染物中，汞（Hg）是一种有毒重金属，会直接对水生生态系统和人类健康造成有害影响。这项研究证实了磁铁矿纳米颗粒（Fe ₃ O ₄ NPs）在体外对水银汞暴露引起的尼罗罗非鱼（Oreochromis niloticus）毒性的体外磁化潜能。我们进一步评估了Fe ₃ O ₄ NP对鱼类生长，血液生化，组织学参数，肌肉生物蓄积和经济性的安全性。表征了磁铁矿纳米颗粒，研究了其对Hg离子的吸附负荷，并测试了不同浓度的Fe ₃ O ₄使用NPs（0.2、0.4、0.6、0.8和1.0 mg / L）确定最高吸附浓度。的体内实验包括120鱼的平均重量为26.2±0.26 g的随机分成4个相等的组，每组三个重复（Ñ  = 30鱼/组; 10鱼/复制）。所有组均以参考基础饮食为食，实验进行了30天。第一组（G ₁）被分配为对照。第二组（G ₂）接受1.0 mg / L Fe ₃ O ₄ NPs的水悬浮液。第三组（G ₃）以0.025mg / L的浓度暴露于Hg离子的水溶液。同时，第四组（G ₄）获得由Hg离子和Fe ₃ O ₄的混合物组成的水悬浮液如前所述的NP。在整个暴露期间，均记录了临床体征，症状和死亡率。暴露于汞离子的基团引起以下后果；食欲下降导致增长减慢，经济效率降低；小细胞性低色素性贫血，白细胞增多症，淋巴细胞减少症和中性粒细胞增多症；包括溶菌酶活性，免疫球蛋白M（IgM）和髓过氧化物酶活性（MPO）在内的免疫指标急剧减少。ALT，AST，尿素，肌酐和超氧化物歧化酶（SOD）显着升高；g，肝和肌肉组织的组织学改变，细胞凋亡标记物（胱天蛋白酶3）表达强；以及汞离子在肌肉中的积累更高。令人惊讶的是，Fe ₃ O ₄NPs补充基团​​对Hg离子具有很强的吸附能力，并且大部分清除了Hg离子在肌肉中的积累。同样，血液学，生化和组织学参数也得到了恢复。因此，为了评估铁的抗毒作用，_3周Ø ₄对汞及其对安全性的NP尼罗罗非鱼，并填补了研究的空白，目前情况下进行了调查，以评估铁的作用，看好_3个Ø _4个纳米粒子来防止汞暴露引起的毒性并保护鱼类健康，这确定了纳米技术在水生环境中可持续发展的必要性。