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-1, wherein 1.5 g L-1 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-1 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.

中文翻译：

---

石榴皮对亚慢性汞对非洲cat鱼（Clarias gariepinus）的免疫毒性的生物修复作用。

本研究的主要目的是评估尼罗河cat鱼（Clarias gariepinus，C. gariepinus）和水样品中的最高重金属（HMs）浓度，并研究石榴皮（PPs）的效率（补充通过水或饮食）增强鱼类的免疫力，并抵消高浓度HMs的毒性。从Al Sharkia省的两个私人养鱼场收集了水和C. gariepinus样本。汞（Hg）显示最高浓度（0.13 ppm）。通过测试0.3、0.6、0.9、1.2和1.5 g L-1的不同浓度来评估PP的吸附容量，其中1.5 g L-1显示出最高的Hg吸附效率。结果表明，汞含量随PP浓度的增加而降低，直至72 h。在持续60天的试验中，温度为240摄氏度。gariepinus（75.12±3.12 g）被随机分为八个相等的组，每组三个重复。第一组（CT）作为阴性对照（以基础饮食喂养的鱼）。第二组（PPW）以基础饮食喂养，并通过水补充0.3 g L-1的PP。第三组（PPD1）和第四组（PPD2）接受的基础饮食富含1和2 g PP粉/ kg饮食。分别。第五组（Hg）作为阳性对照，以基础饮食喂养，并暴露于0.13 ppm的Hg中。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。汞暴露显着提高了天冬氨酸转氨酶（AST），丙氨酸转氨酶（ALT），尿素和肌酐的水平，以及氧化应激生物标记物，包括还原型谷胱甘肽（GSH）和丙二醛（MDA）。通过饮食补充石榴可提高红细胞（RBC），血红蛋白（Hb），细胞堆积量（PCV），溶菌酶和抗蛋白酶活性的水平。此外，通过水补充PP显示尿素和肌酐水平最低，而一氧化氮水平最高。此外，PP处理组鱼肉中的汞残留水平显着降低。这些结果证明了补充PP（通过水或饮食）在增强鱼类免疫力和抵消亚慢性Hg毒性方面的效率。溶菌酶和抗蛋白酶活性。此外，通过水补充PP显示尿素和肌酐水平最低，而一氧化氮水平最高。此外，PP处理组鱼肉中的汞残留量显着降低。这些结果证明了补充PP（通过水或饮食）在增强鱼类免疫力和抵消亚慢性Hg毒性方面的效率。溶菌酶和抗蛋白酶活性。此外，通过水补充PP显示尿素和肌酐水平最低，而一氧化氮水平最高。此外，PP处理组鱼肉中的汞残留水平显着降低。这些结果证明了补充PP（通过水或饮食）在增强鱼类免疫力和抵消亚慢性Hg毒性方面的效率。