Department of Natural Resources and Environmental Engineering, School of Agriculture, Shiraz University, Shiraz, 71441-65186, Iran.
Department of Natural Resources and Environmental Engineering, School of Agriculture, Shiraz University, Shiraz, 71441-65186, Iran.
Fish Shellfish Immunol. 2019 Nov;94:407-416. doi: 10.1016/j.fsi.2019.09.025. Epub 2019 Sep 12.
The aims of this study were to investigate the antibacterial, immunostimulatory and antioxidant properties of different derivatives of Oliveria decumbens, in vitro and in vivo. The GC-MS spectrometry analysis showed γ-terpinene as the most frequent compound in essential oil, whereas carvacrol and thymol were the most common ones in aromatic water. Plant essential oil and hydroethanolic extract showed a positive in vitro bactericidal activity against Streptococcus iniae as evaluated by disc diffusion, minimum inhibitory concentration and minimum bactericidal concentration methods. Also, in vivo resistance against S. iniae and immune and antioxidant responses of Nile tilapia (Oreochromis niloticus) were assayed after 60 days treatment with O. decumbens derivatives. Plant hydroethanolic extract and essential oil and their 1:1 combination were added to diet at 0 (negative control), 0.01, 0.1 and 1% (w:w). The plant aromatic water at doses of 0.0312, 0.0625 and 0.1250% were also used as bath treatment. The results showed that aromatic water at lowest dose was more effective than other treatments in increment of fish resistance against S. iniae (7.14% mortality in comparison with 50% mortalities in control fish) and modulation of post-challenge respiratory burst activity. The bactericidal activity and biochemical contents of skin mucus did not change significantly among treatments. The levels of superoxide dismutase and catalase antioxidant enzymes activities in spleen tissue were significantly higher in treatments received extract, essential oils and their combination in comparison to other groups, while treatments did not affect peroxidase level. In conclusion, administration of different derivatives of Oliveria decumbens showed remarkable antibacterial activity against streptococcosis and enhanced antioxidant status and post-challenge immunity in Nile tilapia.
本研究旨在研究不同奥利维亚衰退衍生物的抗菌、免疫刺激和抗氧化特性，分别在体外和体内进行研究。GC-MS 光谱分析表明，γ-萜品烯是精油中最常见的化合物，而香芹酚和百里酚是芳香水中最常见的化合物。植物精油和水醇提取物对迟缓爱德华氏菌的体外杀菌活性呈阳性，通过圆盘扩散、最小抑菌浓度和最小杀菌浓度方法评估。此外，在 60 天的奥利维亚衰退衍生物处理后，还测定了尼罗罗非鱼（Oreochromis niloticus）对迟缓爱德华氏菌的体内抗性以及免疫和抗氧化反应。植物水醇提取物和精油及其 1:1 混合物以 0（阴性对照）、0.01、0.1 和 1%（w/w）的比例添加到饮食中。植物芳香水以 0.0312、0.0625 和 0.1250%的剂量也用作浴疗。结果表明，最低剂量的芳香水比其他处理更有效地提高了鱼类对迟缓爱德华氏菌的抗性（死亡率为 7.14%，而对照组鱼的死亡率为 50%），并调节了攻毒后呼吸爆发活性。杀菌活性和皮肤黏液的生化含量在处理之间没有显著变化。与其他组相比，在接受提取物、精油及其混合物的处理中，脾脏组织中超氧化物歧化酶和过氧化氢酶抗氧化酶活性的水平显著升高，而处理对过氧化物酶水平没有影响。总之，不同奥利维亚衰退衍生物的给药表现出对链球菌病的显著抗菌活性，并增强了尼罗罗非鱼的抗氧化状态和攻毒后免疫力。
