Cheng Chi, Park Se Chang, Giri Sib Sankar
Laboratory of Aquatic Nutrition and Ecology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, South Korea.
Fish Shellfish Immunol. 2022 Jan;120:287-294. doi: 10.1016/j.fsi.2021.12.004. Epub 2021 Dec 6.
The present study investigated the effect of Pandanus tectorius (PT) extract on Cyprinus carpio growth, antioxidant capacity, immunological and oxidative stress, immune-related gene expression, and resistance against pathogen challenge. Fish (average weight: 12.18 ± 0.32 g) were fed with diets containing various concentration (g kg) of PT extract: 0 g (basal diet), 5 g [PT5], 10 g [PT10], 20 g [PT20], and 30 g [PT30] for 8 weeks. Our results revealed an increase (p < 0.05) in the final weight gain only in the PT20 (63.12 ± 1.4 g) group. Activity of liver antioxidant parameters such as catalase (CAT) (27.67 ± 1.12 U mg protein), superoxide dismutase (SOD) (13.17 ± 0.428 U mg protein), and glutathione peroxidase (GPx) (47.14 ± 1.47 U mg protein) was highest in the PT20 group. Among the serum immunological parameters examined, lysozyme (37.45 ± 0.67 U mL), alternative complement pathway (133.22 ± 1.92 U mL), and phagocytic activities (25.68 ± 0.93%) were high (p < 0.05) in PT20, whereas there was no significant effect on serum immunoglobulin or total protein levels, compared to the control. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and malondialdehyde (MDA) levels were found to be lower (p < 0.05) in the PT20 and PT30 groups than those in the control. However, myeloperoxidase (MPO) levels were significantly higher (p < 0.05) in the PT20 and PT30 groups. Gene expression analysis revealed that mRNA expressions of antioxidant genes (SOD, CAT, nuclear factor erythroid 2-related factor 2) and anti-inflammatory cytokine (IL-10) genes were significantly upregulated in the PT10 - PT30 groups, except for the SOD gene in PT10. Conversely, the signalling molecule NF-κBp65 was downregulated in PT20 and PT30. Expression of Toll-like receptor 22 (TLR22) and hepcidin was significantly upregulated in PT20 and PT30, respectively. Fish in the PT20 group exhibited highest relative post-challenge survival (70.37%) against Aeromonas hydrophila challenge. The results of the present study suggest that dietary supplementation of P. tectorius extract at 20 g kg can significantly improve weight gain, serum antioxidant parameters, strengthen immunity, and increase the disease resistance of C. carpio. Therefore, P. tectorius extract could be exploited for its use as a food additive in aquaculture.
本研究调查了露兜树（PT）提取物对鲤鱼生长、抗氧化能力、免疫及氧化应激、免疫相关基因表达以及抗病原体攻击能力的影响。将平均体重为12.18±0.32克的鱼投喂含不同浓度（克/千克）PT提取物的饲料：0克（基础饲料）、5克[PT5]、10克[PT10]、20克[PT20]和30克[PT30]，持续8周。我们的结果显示，仅PT20组（63.12±1.4克）的最终体重增加（p<0.05）。肝脏抗氧化参数如过氧化氢酶（CAT）（27.67±1.12单位/毫克蛋白质）、超氧化物歧化酶（SOD）（13.17±0.428单位/毫克蛋白质）和谷胱甘肽过氧化物酶（GPx）（47.14±1.47单位/毫克蛋白质）的活性在PT20组中最高。在所检测的血清免疫参数中，PT20组的溶菌酶（37.45±0.67单位/毫升）、替代补体途径（133.22±1.92单位/毫升）和吞噬活性（25.68±0.93%）较高（p<0.05），而与对照组相比，对血清免疫球蛋白或总蛋白水平无显著影响。发现PT20组和PT30组的血清丙氨酸转氨酶（ALT）、天冬氨酸转氨酶（AST）和丙二醛（MDA）水平低于对照组（p<0.05）。然而，PT20组和PT30组的髓过氧化物酶（MPO）水平显著更高（p<0.05）。基因表达分析显示，除PT10组的SOD基因外，PT10 - PT30组的抗氧化基因（SOD、CAT、核因子红细胞2相关因子2）和抗炎细胞因子（IL - 10）基因的mRNA表达显著上调。相反，信号分子NF - κBp65在PT20和PT30组中下调。Toll样受体22（TLR22）和铁调素的表达在PT20组和PT30组中分别显著上调。PT20组的鱼在受到嗜水气单胞菌攻击后表现出最高的相对存活率（70.37%）。本研究结果表明，以20克/千克的剂量在饲料中添加露兜树提取物可显著提高鲤鱼的体重增加、血清抗氧化参数、增强免疫力并提高抗病能力。因此，露兜树提取物可作为水产养殖中的食品添加剂加以利用。
