Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, 159 Longpan Road, Nanjing Jiangsu, 210037, People's Republic of China.
Department of Animal Husbandry and Veterinary Science, Jiangsu Polytechnic College of Agriculture and Forestry, Jurong Jiangsu, 212400, People's Republic of China.
Fish Physiol Biochem. 2022 Feb;48(1):67-83. doi: 10.1007/s10695-021-00992-z. Epub 2022 Jan 1.
This study investigated the effects of dietary Flos populi extract (FPE) on the growth, antioxidation capability, innate immune response, and disease resistance in gibel carp. A total of 480 fish were fed with five different diets containing 0, 0.5, 1.0, 1.5, or 2.0 g kg FPE (designated as control, D0.5, D1.0, D1.5, or D2.0 groups) for 45 days. The fish were challenged with A. hydrophila after the feeding trial. Compared with the control, the feed efficiency (FE), weight gain (WG), final body weight (FBW), and specific growth rate (SGR) were significantly improved in groups D1.0 and D1.5. Dietary FPE significantly increased serum superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activities, as well as glutathione (GSH) content. The contents of protein carbonyl (PCC) and malondialdehyde (MDA) in serum decreased significantly. Additionally, FPE supplementation in diets resulted in significant improvement in serum lysozyme (LZM) and myeloperoxidase (MPO) activities, as well as immunoglobulin M (IgM) and complement 3 (C3) concentrations. The hepatic antioxidant enzymes (CAT and SOD) activities increased, whereas content of MDA decreased in fish treated with dietary FPE than those of control both pre- and post-challenged. After 12 h-challenge, an obvious downregulation of hepatic Kelch-like-ECH-associated protein 1 (Keap1), splenic tumor necrosis factor-α (TNF-α), interleukin (IL)-8, IL-1β, and toll-like receptor 2 (TLR2) mRNA levels was observed in fish treated with dietary FPE, whereas hepatic Nrf2 transcription level was upregulated compared to the control. Furthermore, compared to group D0.5, higher relative percent survival (RPS) was observed in gibel carp fed dietary 1.0-2.0 g/kg FPE. Our results reveal that FPE supplemented diet has a stimulatory effect on antioxidant capacity and nonspecific immune response, along with improved growth performance and enhanced resistance against A. hydrophila infection in juvenile gibel carp.
本研究探讨了日粮白杨素提取物（FPE）对吉富罗非鱼生长、抗氧化能力、先天免疫反应和疾病抵抗力的影响。将 480 条鱼分别投喂 5 种不同饲料，饲料中 FPE 的含量分别为 0、0.5、1.0、1.5 和 2.0 g/kg（分别命名为对照组、D0.5、D1.0、D1.5 和 D2.0 组），为期 45 天。喂养试验结束后，用嗜水气单胞菌对鱼进行攻毒。与对照组相比，D1.0 和 D1.5 组的饲料效率（FE）、增重（WG）、最终体质量（FBW）和特定生长率（SGR）显著提高。日粮 FPE 显著提高了血清中超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GPx）和过氧化氢酶（CAT）的活性以及谷胱甘肽（GSH）的含量。血清蛋白羰基（PCC）和丙二醛（MDA）含量显著降低。此外，饲料中添加 FPE 可显著提高血清溶菌酶（LZM）和髓过氧化物酶（MPO）的活性以及免疫球蛋白 M（IgM）和补体 3（C3）的浓度。经日粮 FPE 处理的鱼在攻毒前后的肝抗氧化酶（CAT 和 SOD）活性增加，而 MDA 含量降低。攻毒 12 h 后，与对照组相比，经日粮 FPE 处理的鱼肝脏 Kelch-like-ECH-associated protein 1（Keap1）、脾脏肿瘤坏死因子-α（TNF-α）、白细胞介素（IL）-8、IL-1β 和 Toll 样受体 2（TLR2）mRNA 水平明显下调，而肝转录因子 Nrf2 水平上调。此外，与 D0.5 组相比，摄食 1.0-2.0 g/kg FPE 日粮的吉富罗非鱼相对百分存活力（RPS）较高。研究结果表明，日粮 FPE 对吉富罗非鱼的抗氧化能力和非特异性免疫反应有刺激作用，能提高生长性能，增强对嗜水气单胞菌感染的抵抗力。
