Department of Fisheries, Faculty of Fisheries and Environmental Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.
Department of Animal and Aquatic Sciences, Faculty of Agriculture, Chiang Mai University, Chiang Mai, 50200, Thailand; Science and Technology Research Institute, Chiang Mai University, 239 Huay Keaw Rd., Suthep, Muang, Chiang Mai, 50200, Thailand.
Fish Shellfish Immunol. 2020 Apr;99:379-385. doi: 10.1016/j.fsi.2020.02.006. Epub 2020 Feb 4.
The use of veterinary drugs for the treatments of fish diseases has often health and environmental side effects and thus alternative more sustainable strategies are needed. In this study we have explored the effect of dietary administration of lemon verbena (Aloysia citrodora) leaves powder on growth, immune parameters and antioxidant enzyme activity of rainbow trout (Oncorrhyncus myskiss). The results show that adding lemon verbena (LV) leaves powder (0.5, 1 and 2%), as feed supplement does not affect significantly rainbow trout growth, but increases the levels of some immune parameters. All enriched-diets induced an increase in the levels of lysozyme activity and total immunoglobulin in rainbow trout serum (P < 0.05), whilst 1 and 2% enriched-diets increased lysozyme and immunoglobulin in skin mucus. Expression of interleukin-1β (IL-1β) was enhanced in all fish supplemented with LV leaves powder (0.5, 1 and 2%) whilst only the diet with the highest dose (2%) induced a significantly higher expression of IL-8 and tumour necrosis factor (TNF-α). Fish fed with LV leaves powder at 1 and 2% had significantly lower expression of transforming growth factor (TGF-β, P < 0.05). Furthermore, all enriched-diets significantly increased the activity of super oxide dismutase (SOD, P < 0.05) and diets containing 1 and 2% of LV leaves powder also increased activity of glutathione-S-transferase (GST) and glutathione peroxidase (GPx). In conclusion, LV leaves powder administered as feed supplement at 2% enhances the expression of some immune-related genes (IL-1β, IL-8 and TNF- α), rises the levels of lysozyme and total immunoglobulin in serum and skin mucus and increases the activity of antioxidant enzymes (SOD, GST and GPx) in rainbow trout.
兽用药物治疗鱼类疾病常常具有健康和环境方面的副作用，因此需要寻找更可持续的替代策略。本研究探索了日粮添加柠檬香蜂草（Aloysia citrodora）叶粉对虹鳟（Oncorrhyncus myskiss）生长、免疫参数和抗氧化酶活性的影响。结果表明，作为饲料补充剂，添加柠檬香蜂草（LV）叶粉（0.5%、1%和 2%）对虹鳟的生长没有显著影响，但提高了一些免疫参数的水平。所有添加了 LV 叶粉的饲料都增加了虹鳟血清中溶菌酶活性和总免疫球蛋白的水平（P<0.05），而 1%和 2%添加饲料则增加了皮肤黏液中的溶菌酶和免疫球蛋白。所有添加 LV 叶粉的鱼的白细胞介素-1β（IL-1β）表达均增强（0.5%、1%和 2%），而只有最高剂量（2%）的饲料诱导了 IL-8 和肿瘤坏死因子（TNF-α）的表达显著增加。用 LV 叶粉喂养的鱼在 1%和 2%时，转化生长因子（TGF-β）的表达显著降低（P<0.05）。此外，所有添加饲料都显著增加了超氧化物歧化酶（SOD）的活性（P<0.05），而含有 1%和 2%LV 叶粉的饲料也增加了谷胱甘肽-S-转移酶（GST）和谷胱甘肽过氧化物酶（GPx）的活性。综上所述，2%的 LV 叶粉作为饲料补充剂可增强一些与免疫相关的基因（IL-1β、IL-8 和 TNF-α）的表达，提高血清和皮肤黏液中溶菌酶和总免疫球蛋白的水平，并增加虹鳟的抗氧化酶（SOD、GST 和 GPx）活性。
