Department of Fish Diseases and Management, Faculty of Veterinary Medicine, Zagazig University, Sharkia, Zagazig, 44511, Egypt.
Environ Sci Pollut Res Int. 2021 Jan;28(2):2219-2235. doi: 10.1007/s11356-020-10599-1. Epub 2020 Sep 1.
The primary aim of the present study is to evaluate the highest concentrations of heavy metals (HMs) in Nile catfish (Clarias gariepinus, C. gariepinus) and water samples, as well as to investigate the efficiency of pomegranate peels (PPs) (supplemented either through water or diet) in enhancing fish immunity and counteracting the toxicity of high concentrations of HMs. Water and C. gariepinus samples were collected from two private fish farms in Al Sharkia Governorate. Mercury (Hg) showed the highest concentration (0.13 ppm). The adsorption capacity of PP was evaluated by testing different concentrations, 0.3, 0.6, 0.9, 1.2, and 1.5 g L, wherein 1.5 g L revealed the highest Hg adsorption efficiency. The results indicated that Hg concentration was decreased with increased PP concentration until 72 h. In a trial that lasted for 60 days, 240 C. gariepinus (75.12 ± 3.12 g) were randomly divided into eight equal groups with three replicates per group. The first group (CT) served as the negative control (fish fed on a basal diet). The second group (PPW) was fed on a basal diet and supplemented with 0.3 g L of PP via water. The third (PPD1) and fourth (PPD2) groups received basal diets enriched with 1 and 2 g PP powder/kg diet. respectively. The fifth group (Hg) served as the positive control that was fed on a basal diet and exposed to 0.13 ppm of Hg. The sixth (Hg + PPW), seventh (Hg + PPD1), and eighth (Hg + PPD2) groups were exposed to 0.13 ppm of Hg and received the same type of treatment as in second, third, and fourth groups. Hg exposure significantly elevated aspartate aminotransferase (AST), alanine aminotransferase (ALT), urea, and creatinine levels, as well as oxidative stress biomarkers, including reduced glutathione (GSH) and malondialdehyde (MDA). Pomegranate supplementation through diet elevated the levels of red blood cells (RBCs), hemoglobin (Hb), packed cell volume (PCV), lysozyme, and anti-protease activity. Moreover, PP supplementation through water revealed minimum urea and creatinine levels, and the highest nitric oxide level. Moreover, Hg residue level in fish muscles noticeably decreased in the PP-treated groups. These results demonstrated the efficiency of PP supplementation (either through water or diet) in enhancing fish immunity and counteracting subchronic Hg toxicity.
本研究的主要目的是评估尼罗罗非鱼（Clarias gariepinus，C. gariepinus）和水样中重金属（HMs）的最高浓度，并研究石榴皮（PPs）（通过水或饮食补充）在增强鱼类免疫力和抵抗高浓度 HMs 毒性方面的效率。水样和尼罗罗非鱼样本取自艾尔夏甲省的两个私人鱼类养殖场。汞（Hg）的浓度最高（0.13 ppm）。通过测试不同浓度（0.3、0.6、0.9、1.2 和 1.5 g/L）来评估 PP 的吸附能力，其中 1.5 g/L 的 Hg 吸附效率最高。结果表明，Hg 浓度随着 PP 浓度的增加而降低，直到 72 小时。在为期 60 天的试验中，随机将 240 尾重 75.12±3.12 g 的尼罗罗非鱼分为 8 组，每组 3 个重复。第一组（CT）作为阴性对照（鱼用基础饲料喂养）。第二组（PPW）用基础饲料喂养，并通过水补充 0.3 g/L 的 PP。第三（PPD1）和第四组（PPD2）分别用含有 1 和 2 g PP 粉/kg 饲料的基础饲料饲养。第五组（Hg）作为阳性对照，用基础饲料喂养并暴露于 0.13 ppm 的 Hg。第六组（Hg+PPW）、第七组（Hg+PPD1）和第八组（Hg+PPD2）暴露于 0.13 ppm 的 Hg，并接受与第二、第三和第四组相同的处理。Hg 暴露显著升高了天冬氨酸氨基转移酶（AST）、丙氨酸氨基转移酶（ALT）、尿素和肌酐水平，以及氧化应激生物标志物，包括还原型谷胱甘肽（GSH）和丙二醛（MDA）。通过饮食补充石榴皮提高了红细胞（RBCs）、血红蛋白（Hb）、红细胞压积（PCV）、溶菌酶和抗蛋白酶活性的水平。此外，通过水补充石榴皮可使尿素和肌酐水平降至最低，并使一氧化氮水平达到最高。此外，鱼肌肉中的 Hg 残留量在添加 PP 的组中明显减少。这些结果表明，通过水或饮食补充石榴皮可以提高鱼类免疫力，抵抗亚慢性 Hg 毒性。
