Negash Nigatu, Andualem Dereje, Mandefro Belayhun
Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
Department of Biology, College of Natural and Computational Sciences, Dilla University, Dilla, Ethiopia.
J Exp Pharmacol. 2024 Jul 23;16:243-255. doi: 10.2147/JEP.S454655. eCollection 2024.
Ticks are the second most common vector of human infectious diseases after mosquitoes. Their transovarial transmission contributes to the maintenance of environmental diseases. This study evaluates the phytochemical screening and in vitro efficacy of Calpurnia aurea against the adult survival and egg hatchability of two transovarial transmission vectors: Amblyomma variegatum and Rhipicephalus microplus.
Plant material was extracted using maceration techniques, and concentrated solutions of 12.5, 25, 50, 100, 200, and 400 ppm were prepared. Distilled water and diazinon were used as negative and positive controls, respectively. Ten adult ticks were exposed for 10 minutes, and dead ticks were counted after 24 hours of recovery. Twenty 15-day-old eggs were immersed for 10 minutes, and after 15 days of incubation, hatched and unhatched eggs were tallied. Preliminary phytochemical constituents were screened. A one-way analysis of variance and the probit regression model determined mean mortality and hatchability and estimated lethal and inhibitory concentrations, respectively.
The ethanolic and aqueous leaf extracts caused 10±0.0% mortality in adult A. variegatum and R. microplus. The effective dose was LC50 of 27 and 29 ppm and LC50 of 37 and 41 ppm, respectively. At 400 ppm, the leaf ethanolic and aqueous extracts showed 18.7±0.9% and 18.3±1.7%; 18.3±1.2% and 19.7±0.3% egg hatching inhibition, respectively. The effective dose had an IC50 of 50 ppm and IC50s of 91 and 79 ppm, respectively. Flavonoids and saponins were found in both leaf and pod extracts.
C. aurea extracts showed a more promising effect on tick survival and hatchability than synthetic diazinon. The susceptibility test indicated that the leaf extract could control vectors and contribute to environmental disease maintenance. Complex phytochemicals, especially phenolic compounds, are additional evidence of effectiveness in vector control. Further investigation of in vivo efficacy and advanced fractionation of phytochemicals is needed.
蜱是仅次于蚊子的人类传染病第二常见传播媒介。它们的经卵传播有助于维持环境性疾病。本研究评估了黄野百合对两种经卵传播媒介——变异革蜱和微小牛蜱的成虫存活及卵孵化率的植物化学筛选及体外效果。
采用浸渍技术提取植物材料，并制备了浓度为12.5、25、50、100、200和400 ppm的浓缩溶液。分别使用蒸馏水和二嗪农作为阴性和阳性对照。将10只成年蜱暴露10分钟，恢复24小时后统计死亡蜱的数量。将20枚15日龄的卵浸泡10分钟，孵化15天后统计孵化和未孵化的卵数。对初步的植物化学成分进行筛选。采用单因素方差分析和概率回归模型分别确定平均死亡率和孵化率，并估计致死浓度和抑制浓度。
乙醇叶提取物和水叶提取物对成年变异革蜱和微小牛蜱的死亡率为10±0.0%。有效剂量的LC50分别为27和29 ppm以及37和41 ppm。在400 ppm时，叶乙醇提取物和水提取物的卵孵化抑制率分别为18.7±0.9%和18.3±1.7%；18.3±1.2%和19.7±0.3%。有效剂量的IC50为50 ppm，IC50分别为91和79 ppm。在叶提取物和荚提取物中均发现了黄酮类化合物和皂苷。
黄野百合提取物对蜱的存活和孵化率的影响比合成二嗪农更有前景。药敏试验表明，叶提取物可控制传播媒介并有助于维持环境性疾病。复杂的植物化学成分，尤其是酚类化合物，是其在媒介控制中有效性的额外证据。需要进一步研究其体内效果及植物化学成分的高级分离。
