在鱼中,应激事件沿下丘脑-垂体-肾间和下丘脑-交感神经-嗜铬细胞(HSC)轴引发激素级联反应,以引起多种生理反应,以协调和维持稳态。几种生物和非生物因素,以及水产养殖程序(处理,运输,或放养密度),激活的应激系统对鱼类不同生理过程(生长,繁殖,和豁免权)。为了减少这些后果,使用源自植物的精油(EO)由于其不同的特性而成为水产养殖研究的重点(例如,麻醉剂,抗氧化剂,和抗菌),已被证明可以减少生化和内分泌改变,因此,改善福利状况。最近,一些研究表明,从不同的EO中分离出的生物化合物具有优异的生物活性,以及这些EO的纳米封装形式可以增强它们的作用。总的来说,EO的副作用比合成化合物少,但是它们的减压功效与它们的化学成分有关,使用的浓度或化学型。此外,必须明确确定它们的物种特异性作用,因为如果它们的浓度和使用的化学型不合适,它们可以自己充当应激源。出于这个原因,有必要评估这些天然化合物混合物在不同鱼类中的作用,从海洋到淡水,为了找到理想的浓度范围和给药方式,以获得所需的生物活性,没有任何不希望的副作用。在这次审查中,将介绍有关使用不同EO作为减压剂的主要发现,以突出与使用EO改善水产养殖鱼类福利有关的最重要问题。
In fish, stressful events initiate a hormone cascade along the hypothalamus-pituitary-interrenal and hypothalamus-sympathetic-chromaffin (HSC) axis to evoke several physiological reactions in order to orchestrate and maintain homeostasis. Several biotic and abiotic factors, as well as aquaculture procedures (handling, transport, or stocking density), activated stress system inducing negative effects on different physiological processes in fish (growth, reproduction, and immunity). In order to reduce these consequences, the use of essential oils (EOs) derived from plants has been the focus of aquaculture studies due to their diverse properties (e.g., anesthetic, antioxidant, and antimicrobial), which have been shown to reduce biochemical and endocrine alterations and, consequently, to improve the welfare status. Recently, several studies have shown that biogenic compounds isolated from different EOs present excellent biological activities, as well as the nanoencapsulated form of these EOs may potentiate their effects. Overall, EOs presented less side effects than synthetic compounds, but their stress-reducing efficacy is related to their chemical composition, concentration or chemotype used. In addition, their species-specific actions must be clearly established since they can act as stressors by themselves if their concentrations and chemotypes used are not suitable. For this reason, it is necessary to assess the effect of these natural compound mixtures in different fish species, from marine to freshwater, in order to find the ideal concentration range and the way for their administration to obtain the desired biological activity, without any undesired side effects. In this
review, the main findings regarding the use of different EOs as stress reducers will be presented to highlight the most important issues related to their use to improve fish welfare in aquaculture.