Firat University, Fisheries Faculty, Department of Aquaculture, Elazig, Turkey.
Fish Shellfish Immunol. 2019 Dec;95:391-398. doi: 10.1016/j.fsi.2019.10.056. Epub 2019 Oct 29.
The present study was performed to investigate the effects of various levels of dietary ellagic acid (EA) on growth performance, haematological values, immune response, protection against Yersinia ruckeri infection, and oxidant/antioxidant status in rainbow trout, Oncorhynchus mykiss. Fish were fed with the control diet and three different experimental diets containing three graded levels of EA (50, 100 and 200 mg kg diet) for 8 weeks. At the end of the experiment, the growth performance [weight gain (WG), specific growth rate (SGR) and feed conversion ratio (FCR)], haematological values [the red blood cell (RBC) count, haemoglobin (Hb) concentration, haematocrit (Ht) level and erythrocyte indices: mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC)], immune response [white blood cell (WBC) count, oxidative radical production (nitroblue tetrazolium (NBT) assay), phagocytic activity (PA) and phagocytic index (PI), total protein (TP) and immunoglobulin M (IgM) levels, serum bactericidal activity (BA), lysozyme (LYZ) and myeloperoxidase (MPO) activities] and oxidant/antioxidant status [tissue malondialdehyde (MDA) levels and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities] were analysed. In addition, fish were challenged by Y. ruckeri and survival rate was recorded for 14 days. In the groups fed with EA the growth parameters such as WG, SGR, and FCR did not vary significantly. The RBC count, Hb concentration, and Ht level increased in the groups fed with EA when compared with the control group. However, there were no significant differences in the MCV, MCH and MCHC values among the groups. The results demonstrated enhancement in all the immunological parameters in the groups fed with EA compared to the control group. The results obtained from challenge with Y. ruckeri revealed reduction in the mortalities in the groups fed with EA. The dietary EA stimulated the SOD, CAT and GSH-Px activities in liver, head kidney and spleen as compared to the control group; however, a reverse trend was observed in the MDA levels of tissues. The present study suggest that EA can effectively enhance the haematological values, immune response, antioxidant capacity, and disease resistance in rainbow trout.
本研究旨在探讨日粮中不同水平的鞣花酸（EA）对虹鳟生长性能、血液学指标、免疫反应、抗迟钝爱德华氏菌感染的保护作用以及氧化应激/抗氧化状态的影响。将鱼分为对照组和实验组，实验组分别投喂三种不同 EA 含量（50、100 和 200mg/kg 饲料）的实验饲料，为期 8 周。试验结束时，分析了生长性能（增重率（WG）、特定生长率（SGR）和饲料转化率（FCR））、血液学指标（红细胞计数、血红蛋白浓度、血细胞比容水平和红细胞指数：平均红细胞体积（MCV）、平均红细胞血红蛋白（MCH）和平均红细胞血红蛋白浓度（MCHC））、免疫反应（白细胞计数、氧化自由基产生（硝基四唑蓝（NBT）测定）、吞噬活性（PA）和吞噬指数（PI）、总蛋白（TP）和免疫球蛋白 M（IgM）水平、血清杀菌活性（BA）、溶菌酶（LYZ）和髓过氧化物酶（MPO）活性）以及氧化应激/抗氧化状态（组织丙二醛（MDA）水平和超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和谷胱甘肽过氧化物酶（GSH-Px）活性）。此外，用迟钝爱德华氏菌对鱼进行攻毒，记录 14 天的存活率。与对照组相比，投喂 EA 的鱼的生长参数（WG、SGR 和 FCR）没有显著变化。与对照组相比，投喂 EA 的鱼的红细胞计数、血红蛋白浓度和血细胞比容水平升高。然而，各组之间的 MCV、MCH 和 MCHC 值没有显著差异。与对照组相比，投喂 EA 的鱼的所有免疫参数均得到增强。用迟钝爱德华氏菌攻毒的结果表明，投喂 EA 的鱼的死亡率降低。与对照组相比，日粮 EA 刺激了肝脏、头肾和脾脏中的 SOD、CAT 和 GSH-Px 活性；然而，组织中的 MDA 水平呈相反趋势。本研究表明，EA 可有效提高虹鳟的血液学指标、免疫反应、抗氧化能力和抗病能力。
