Department of Veterinary Pharmacology, Faculty of Veterinary Medicine, Alexandria University, Alexandria, Egypt.
Department of Poultry and Fish Diseases, Faculty of Veterinary Medicine, Alexandria University, Alexandria, Egypt.
Environ Sci Pollut Res Int. 2022 Jan;29(5):6777-6792. doi: 10.1007/s11356-021-15630-7. Epub 2021 Aug 30.
This study was carried out to evaluate the effects of dietary supplementation of aqueous extract of Withania somnifera (W. somnifera) against cadmium chloride-induced toxicity in the Nile tilapia, Oreochromis niloticus. Five experimental groups were designed: group (I) was free from cadmium chloride and W. somnifera and served as a control, group (II) was exposed to 1.775 mg L of cadmium chloride only (which is equivalent to 1/4 96-h LC50), while groups (III), (IV), and (V) were exposed to 1.775 mg cadmium chloride L with co-supplementation of dietary W. somnifera in doses of 1.0, 2.0, and 3.0 mL kg body weight (bwt), respectively. The experiment lasted for 4 weeks. In the second and fourth weeks of the experiment, the following indicators were evaluated: hematological (hemogram and blood protein profile), biochemical (activities of serum liver enzymes, namely alanine transaminase (ALT) and aspartate transaminase (AST)), immunological (immunoglobulin M (IgM), serum lysozyme), and tissue antioxidant changes (malondialdehyde (MDA) levels and activities of catalase (CAT) and superoxide dismutase (SOD)). Additionally, gene expressions of glutathione-S-transferase (GST) in the liver were assessed. At the end of the experiment, all fish in all groups were experimentally challenged with Aeromonas hydrophila and the relative protection survival (RPS) was demonstrated. The results revealed that groups exposed to cadmium chloride toxicity and co-supplemented with dietary aqueous extract of W. somnifera at high doses showed significant ameliorative effects in hemogram parameters, total protein, globulin, IgM, and lysozyme against cadmium chloride-induced toxicity compared to the control group and the group exposed to a sublethal dose of cadmium chloride without co-suplemntation of W. somnifera. The results showed also that groups supplemented orally with W. somnifera at high doses have higher antioxidant activities of CAT and SOD and reduction of MDA formation. Levels of gene expressions of GST in the liver were higher in W. somnifera extract-supplemented groups more than those in the group exposed to cadmium chloride-induced toxicity without W. somnifera supplementation. In addition, the results revealed improved RPS with the dietary supply of W. somnifera extract in high doses. In conclusion, this study showed that the dietary supplementation of W. somnifera extract to diets of O. niloticus could be suggested as an effective way to overcome cadmium chloride-induced toxicity because it improves blood parameters and antioxidants, and it can be used as an immunostimulant against the invading bacterial pathogens.
这项研究旨在评估用茄科植物印度人参（Withania somnifera）水提物作为膳食补充剂对尼罗罗非鱼（Oreochromis niloticus）氯化镉毒性的影响。设计了五个实验组：第 I 组未接触氯化镉和印度人参，作为对照组；第 II 组仅接触 1.775mg/L 的氯化镉（相当于 96 小时 LC50 的 1/4）；第 III、IV 和 V 组接触 1.775mg/L 的氯化镉，并分别用 1.0、2.0 和 3.0mL/kg 体重的印度人参水提物作为膳食补充剂。实验持续 4 周。在实验的第二和第四周，评估了以下指标：血液学（血象和血液蛋白谱）、生化（血清肝酶活性，即丙氨酸转氨酶（ALT）和天冬氨酸转氨酶（AST））、免疫学（免疫球蛋白 M（IgM）、血清溶菌酶）和组织抗氧化变化（丙二醛（MDA）水平和过氧化氢酶（CAT）和超氧化物歧化酶（SOD）的活性）。此外，还评估了肝脏谷胱甘肽-S-转移酶（GST）的基因表达。实验结束时，所有鱼都用嗜水气单胞菌进行了实验性攻毒，并证明了相对保护存活率（RPS）。结果表明，与对照组和未用印度人参水提物补充亚致死剂量氯化镉的组相比，暴露于氯化镉毒性并高剂量补充膳食印度人参水提物的组，在血象参数、总蛋白、球蛋白、IgM 和溶菌酶方面均有显著改善作用。结果还表明，高剂量口服补充印度人参的组 CAT 和 SOD 的抗氧化活性更高，MDA 的形成减少。肝脏 GST 基因表达水平在补充印度人参提取物的组中高于未补充印度人参提取物的暴露于氯化镉诱导毒性的组。此外，结果表明，高剂量膳食印度人参提取物的补充提高了相对保护存活率。总之，本研究表明，用茄科植物印度人参水提物作为膳食补充剂添加到尼罗罗非鱼的饲料中，可以作为克服氯化镉诱导毒性的有效方法，因为它可以改善血液参数和抗氧化剂，还可以作为对抗入侵的细菌病原体的免疫刺激剂。
