Mandefro Belayhun, Fereja Workineh Mengesha, Fremichael Dawit, Mereta Seid Tiku, Ambelu Argaw
Department of Environmental Health Science and Technology, Jimma University, Jimma, Ethiopia.
Department of Biology, Dilla University, Dilla, Ethiopia.
Biochem Biophys Rep. 2023 Dec 27;37:101624. doi: 10.1016/j.bbrep.2023.101624. eCollection 2024 Mar.
Schistosomiasis is a debilitating chronic disease with great socioeconomic and public health impact affecting the poor rural populations who lack access to sanitation, and safe water supply. The high cost of synthetic molluscicides, their toxicity to non-target organisms, and their persistence in the environment have forced the research of plant-derived molluscicides. Although plant molluscicides are cheap, biodegradable, ecofriendly and less toxic to higher animals, unregulated applications could affect non-target organisms. Therefore, ecotoxicological studies are essential to assess the toxicity of these substances to economically and ecologically significant fish species and to establish safe dosage level. This study is intended to investigate the acute toxicity of a molluscicidal plant to Nile tilapia fingerlings, (O. niloticus) (n = 7) were exposed to serial dilutions of leaf aqueous extract using maceration method for 96 h in triplicate setup. Phytoconstituents were identified by GC-MS. Mortality data were analyzed by probit regression to determine lethal concentrations. The NOAEC was ascertained through hypothesis testing based on survival data. The respective piscicidal LC and LC values were 897.43 and 1063.87 mg/L while the LC is 1310.74 mg/L. In addition, the NOAEC was 1100 mg/L (p > 0.05). This piscicidal toxicity is much lower than its molluscicidal potency may be due to the presence of rotenones and triterpenoides which are commonly found in piscicidal natural products. The GC-MS analysis revealed 12 phytoconstituents including a monoterpene. This study indicates that has low toxicity to Nile tilapia could be due to monoterpenes are nontoxic. The findings of this study demonstrate that, at this dose, the plant is safe to the test fish. Thus it can be effective, eco-friendly and sustainable alternative for the development of molluscicides for snail control.
血吸虫病是一种使人衰弱的慢性疾病，对社会经济和公共卫生有重大影响，影响着缺乏卫生设施和安全供水的贫困农村人口。合成杀螺剂成本高昂、对非目标生物有毒性且在环境中持久存在，这促使人们对植物源杀螺剂进行研究。尽管植物杀螺剂价格低廉、可生物降解、生态友好且对高等动物毒性较小，但无节制使用可能会影响非目标生物。因此，生态毒理学研究对于评估这些物质对具有经济和生态意义的鱼类的毒性以及确定安全剂量水平至关重要。本研究旨在调查一种杀螺植物对尼罗罗非鱼幼鱼的急性毒性，将7尾尼罗罗非鱼幼鱼（O. niloticus）采用浸渍法暴露于叶水提取物的系列稀释液中96小时，设置三个重复。通过气相色谱 - 质谱联用仪（GC - MS）鉴定植物成分。通过概率回归分析死亡率数据以确定致死浓度。基于生存数据通过假设检验确定无观察到有害作用浓度（NOAEC）。杀鱼的半数致死浓度（LC）和最低致死浓度（LC）值分别为897.43和1063.87毫克/升，而最高致死浓度（LC）为1310.74毫克/升。此外，无观察到有害作用浓度为1100毫克/升（p＞0.05）。这种杀鱼毒性远低于其杀螺效力，可能是由于在杀鱼天然产物中常见的鱼藤酮和三萜类化合物的存在。气相色谱 - 质谱联用仪分析揭示了12种植物成分，包括一种单萜。本研究表明对尼罗罗非鱼毒性低可能是由于单萜无毒。本研究结果表明，在此剂量下，该植物对受试鱼类是安全的。因此，它可以成为开发用于控制蜗牛的杀螺剂的有效、生态友好且可持续的替代品。
