Department of Fish Diseases and Management, Faculty of Veterinary Medicine, Zagazig University, P.O. Box 44511, Zagazig, Sharkia, Egypt.
Aquatic Animal Diseases Laboratory, Department of Aquaculture, National Institute of Oceanography and Fisheries, P.O. Box 43511, Suez, Egypt.
Aquat Toxicol. 2022 Aug;249:106238. doi: 10.1016/j.aquatox.2022.106238. Epub 2022 Jul 14.
Silica nanoparticles (SiNPs) are among the non-toxic nanoparticles (NPs) that have magnetic capabilities. It is hypothesized that SiNPs may be able to reduce toxic effects exerted by a mixture of lead (Pb) and mercury (Hg) in African catfish Clarias gariepinus. The in vitro magnetic potential of SiNPs to absorb Pb and Hg was tested. Fish (N = 240) were divided into four groups in triplicates for 30 days. The first group served as control and the second group (SiNPs) was exposed to 1/10 of 96 h LC50 of SiNPs (14.45 mg/L). The third group (HMM) was exposed to 1/10 of 96-h LC50 of a mixture of mercury chloride (HgCl) and lead chloride (PbCl) equal to 0.04 mg/ L and 23.1 mg/L. The fourth group (SiNPs+ HMM) was exposed to a suspension composed of SiNPs, HgCl, and PbCl at the same concentrations as the third group. Results showed that fish exposed to heavy metals revealed the following consequences; a significant decrease in hematological, immunological (complement-3 and nitric oxide), and antioxidants (total antioxidant capacity, glutathione peroxidase, superoxide dismutase, and catalase) indices, down-regulation of IL-1β, IL-8, TGF-β, NF-κβ, HSP70, and Hepcidin genes, the highest mortality rate (48.33%), higher values of alkaline phosphatase, alanine, and aspartate aminotransferases, urea, creatinine, and branchial malondialdehyde, marked up-regulation of CC chemokine and CXC chemokines, and high HMs residues levels in muscles. Extensive pathology showed degeneration with diffuse vacuolation of hepatopancreatic cells and hemorrhage in the HMM group. Interestingly, the exposed group to SiNPs and HMM demonstrated a decline of HMs concentration in fish muscles and modulated the abovementioned parameters with the regeneration of histological alterations of liver and gills. Based on the study outcomes, we highlight the importance and the safety of SiNPs as a novel aqueous additive to alleviate HMs toxicity and recommend using SiNPs for enhancing fish performance for sustaining aquaculture without adverting safety of human health by their little accumulation in muscular tissue.
硅纳米颗粒（SiNPs）是具有磁性的无毒纳米颗粒（NPs）之一。据推测，SiNPs 可能能够减少铅（Pb）和汞（Hg）混合物对非洲鲶鱼 Clarias gariepinus 的毒性影响。本研究测试了 SiNPs 体外磁性吸附 Pb 和 Hg 的能力。将 240 条鱼分为 4 组，每组 30 天。第一组作为对照组，第二组（SiNPs）暴露于 SiNPs96 小时 LC50 的 1/10（14.45mg/L）。第三组（HMM）暴露于等浓度的氯化汞（HgCl）和氯化铅（PbCl）混合物的 96 小时 LC50 的 1/10，即 0.04mg/L 和 23.1mg/L。第四组（SiNPs+HMM）暴露于由 SiNPs、HgCl 和 PbCl 组成的悬浮液中，浓度与第三组相同。结果表明，暴露于重金属的鱼类表现出以下后果；血液学、免疫学（补体-3 和一氧化氮）和抗氧化剂（总抗氧化能力、谷胱甘肽过氧化物酶、超氧化物歧化酶和过氧化氢酶）指数显著降低，IL-1β、IL-8、TGF-β、NF-κβ、HSP70 和 Hepcidin 基因下调，死亡率最高（48.33%），碱性磷酸酶、丙氨酸和天冬氨酸转氨酶、尿素、肌酐和鳃丙二醛值升高，CC 趋化因子和 CXC 趋化因子显著上调，肌肉中 HM 残留水平升高。HMM 组广泛病理学显示肝胰腺细胞弥漫性空泡变性和出血。有趣的是，暴露于 SiNPs 和 HMM 的组鱼肌肉中 HM 浓度下降，并通过肝和鳃组织学改变的再生来调节上述参数。基于研究结果，我们强调了 SiNPs 作为一种新型水添加剂的重要性和安全性，以减轻 HMs 毒性，并建议使用 SiNPs 来提高鱼类的性能，以维持水产养殖，而不会因它们在肌肉组织中的少量积累而对人类健康造成安全风险。
