Levy G, Zilberg D, Paladini G, Fridman S
Institute of Aquaculture, University of Stirling, Stirling FK9 4LA, Scotland, United Kingdom.
French Associates' Institute for Agriculture and Biotechnology of Drylands, Ben Gurion University of the Negev, Sde Boqer Campus, 84990 Israel.
Vet Parasitol. 2015 Apr 30;209(3-4):235-41. doi: 10.1016/j.vetpar.2015.03.002. Epub 2015 Mar 16.
Monogenean infections of commercially farmed fishes are responsible for significant economic losses and existing chemical therapeutants, often stressful to the fish, pose associated risks. As part of a recent trend to move towards the use of alternative, plant-based remedies for commonly occurring aquaculture-related diseases, the efficiency of ginger (Zingiber officinale) was investigated against the monogenean parasite Gyrodactylus turnbulli in the guppy. In vitro trials revealed the clear anti-parasitic effects of ginger. Ethanolic and aqueous extracts, prepared from freeze dried ginger, were tested. An increase in extract concentration was associated with reduced time to parasite immobilisation, with ethanolic extract being more efficient; at 75 and 200ppt aqueous ginger extract parasites died at 65.6±2.8 and 1.8±0.2min, respectively, whereas at 5 and 40ppt ethanolic extract parasites died at 26.1±0.7 and 4.9±0.3min, respectively. Bathing G. turnbulli-infected fish in ethanolic ginger extract (i.e. 5 and 7.5ppt for 90 and 30min, respectively) significantly reduced infection prevalence and intensity when compared to the water and ethanol controls. The higher concentration (i.e. 7.5ppt) proved as equally effective as Praziquantel, the conventionally used chemical treatment for gyrodactylosis, with the fish appearing to be completely cleared of the infection in both cases. Oral treatments of G. turnbulli-infected guppies with diets supplemented with 10 and 20% ginger powder proved to be ineffective in decreasing parasite load. These findings demonstrate that immersion in ginger extract offers an effective, alternative treatment against monogenean infection in fish.
商业化养殖鱼类的单殖吸虫感染会造成重大经济损失，而现有的化学治疗剂往往会给鱼类带来压力，并存在相关风险。作为最近转向使用替代的、基于植物的疗法来治疗常见水产养殖相关疾病这一趋势的一部分，研究了生姜（姜科姜属植物）对孔雀鱼体内单殖吸虫寄生虫特氏三代虫的治疗效果。体外试验显示出生姜具有明显的抗寄生虫作用。对由冻干生姜制备的乙醇提取物和水提取物进行了测试。提取物浓度的增加与寄生虫固定时间的减少相关，乙醇提取物的效果更佳；在75和200ppt时，生姜水提取物中的寄生虫分别在65.6±2.8分钟和1.8±0.2分钟死亡，而在5和40ppt时，乙醇提取物中的寄生虫分别在26.1±0.7分钟和4.9±0.3分钟死亡。与水和乙醇对照组相比，将感染特氏三代虫的鱼浸泡在乙醇生姜提取物中（即分别以5和7.5ppt浸泡90和30分钟）可显著降低感染率和感染强度。较高浓度（即7.5ppt）的效果与吡喹酮（传统用于治疗三代虫病的化学药物）相当，在这两种情况下，鱼体内的感染似乎都被完全清除。用添加了10%和20%姜粉的饲料对感染特氏三代虫的孔雀鱼进行口服治疗，结果证明在降低寄生虫数量方面无效。这些发现表明，浸泡在生姜提取物中可为鱼类单殖吸虫感染提供一种有效的替代治疗方法。
