Yousefi Morteza, Hoseini Seyyed Morteza, Kulikov Evgeny Vladimirovich, Seleznev Sergey Borisovich, Petrov Aleksandr Konstantinovich, Babichev Nikolay Valerievich, Kochneva Margarita Vasilyevna, Davies Simon John
Department of Veterinary Medicine, Peoples' Friendship University of Russia (RUDN University), Moscow, Russia.
Inland Waters Aquatics Resources Research Center, Iranian Fisheries Sciences Research Institute, Agricultural Research, Education and Extension Organization, Gorgan, Iran.
Front Vet Sci. 2022 Oct 20;9:1042063. doi: 10.3389/fvets.2022.1042063. eCollection 2022.
The present study aimed at assessing the effects of dietary Hyssop, , extract on rainbow trout, , responses to thermal stress. The juveniles (69.8 ± 0.38 g) were stocked in 12 through-flow tanks at a density of 12 fish per tank. Methanolic extract of Hyssop (HME) was added to diet at 0, 100, 250, and 500 mg/kg and the fish were fed (3% of biomass) over a 70-d period: 62 d at 13.3 ± 0.08°C and 7 d at 21-22°C. At the end of the trial, the plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), triiodothyronine (T3), thyroxin (T4), cortisol, glucose, lactate, total antioxidant capacity (TAC), ascorbate, and the gill glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), and malondialdehyde (MDA). The results showed that HME had no significant effects on fish growth performance, survival, and feed efficiency. Dietary 250 mg/kg HME significantly decreased plasma ALT activity ( < 0.001), but showed no significant effects on plasma AST) ( = 0.106) activity, T3 ( = 0.992), and T4 ( = 0.070) levels. Thermal stress significantly ( < 0.001) increased plasma ALT and AST activities, but lowered plasma T3 and T4 levels. Dietary HME and thermal stress had interaction effects on plasma cortisol ( < 0.001), glucose ( = 0.007), lactate ( = 0.010), LDH ( = 0.005), TAC ( = 0.038), ascorbate ( < 0.001), and the gill GPx ( = 0.001), GR ( < 0.001), GST ( < 0.001), and MDA ( = 0.001). Thermal stress significantly increased plasma cortisol, glucose, lactate, and LDH, the gill GPX, GR, and GST, but dietary HME supplementation significantly reduced such elevations, particularly at 250 mg/kg level. Dietary HME significantly increased plasma TAC before the thermal stress and mitigated the stress-induced decreased in TAC, particularly at 250 mg/kg level. Dietary HME significantly decreased the gill MDA before and after the thermal stress, and lowest MDA was observed in 250 mg/kg HME level. Based on the present results, 250 mg/kg HME is recommended as suitable dose to improve antioxidative responses and hepatoprotection in rainbow trout under heat stress.
本研究旨在评估日粮中牛膝草提取物对虹鳟鱼热应激反应的影响。将幼鱼（69.8±0.38克）以每箱12尾的密度放养在12个流水箱中。将牛膝草甲醇提取物（HME）以0、100、250和500毫克/千克的剂量添加到日粮中，并在70天的时间里（3%生物量）投喂这些鱼：在13.3±0.08°C下饲养62天，在21-22°C下饲养7天。试验结束时，检测血浆丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）、乳酸脱氢酶（LDH）、三碘甲状腺原氨酸（T3）、甲状腺素（T4）、皮质醇、葡萄糖、乳酸、总抗氧化能力（TAC）、抗坏血酸，以及鳃中的谷胱甘肽过氧化物酶（GPx）、谷胱甘肽还原酶（GR）、谷胱甘肽-S-转移酶（GST）和丙二醛（MDA）。结果表明，HME对鱼的生长性能、存活率和饲料效率没有显著影响。日粮中添加250毫克/千克HME显著降低了血浆ALT活性（P<0.001），但对血浆AST活性（P = 0.106）、T3（P = 0.992）和T4（P = 0.070）水平没有显著影响。热应激显著（P<0.001）增加了血浆ALT和AST活性，但降低了血浆T3和T4水平。日粮HME和热应激对血浆皮质醇（P<0.001）、葡萄糖（P = 0.007）、乳酸（P = 0.010）、LDH（P = 0.005）、TAC（P = 0.038）、抗坏血酸（P<0.001），以及鳃中的GPx（P = 0.001）、GR（P<0.001）、GST（P<0.001）和MDA（P = 0.001）有交互作用。热应激显著增加了血浆皮质醇、葡萄糖、乳酸和LDH，以及鳃中的GPX、GR和GST，但日粮中添加HME显著降低了这些升高水平，尤其是在250毫克/千克剂量时。日粮HME在热应激前显著增加了血浆TAC，并减轻了应激诱导的TAC降低，尤其是在250毫克/千克剂量时。日粮HME在热应激前后均显著降低了鳃中的MDA，在250毫克/千克HME剂量时观察到最低的MDA。基于目前的结果，建议250毫克/千克HME作为改善热应激下虹鳟鱼抗氧化反应和肝脏保护的合适剂量。
