Federal University of Pelotas, Department of Microbiology and Parasitology, Brazil.
Federal University of Pelotas, Department of Preventive Veterinary Medicine, Brazil.
Vet Parasitol. 2023 Feb;314:109863. doi: 10.1016/j.vetpar.2022.109863. Epub 2022 Dec 21.
Fasciolosis is one of the most important parasitic diseases in animal health, affecting mainly ruminants, causing economic and productivity losses. This study aimed to evaluate the in vitro ovicidal and adulticidal activity of essential oils (EOs) from Pelargonium graveolens (geranium) and Citrus aurantium (sour orange) on Fasciola hepatica. Performed Gas Chromatography of EOs P. graveolens and C. aurantium, with major compound, citronellol (31.37 %) and limonene (93.89 %), respectively. For the cytotoxicity assay, the sour orange EO showed to be promising when used in lower concentrations. For the ovicidal tests, the eggs were incubated with geranium EOs at concentrations from 4.5 to 0.03375 mg/mL and sour orange at concentrations from 4.25 to 0.031875 mg/mL, along with controls. The viable eggs were counted on the 14th day post-incubation. Adult forms of F. hepatica were incubated containing the EOs and observed for 24 h after treatment, as well as the control groups. Later the specimens were fixed for histological analysis. Geranium and sour orange EOs in trematode eggs at the concentrations tested were 100 % effective in inactivating hatching (p < 0.05) when compared to the untreated control. In the adulticidal test, the essential oil of P. graveolens at both concentrations tested (0.0675 and 0.03375) within 15 h, promoted the death of flukes. For C. aurantium, 18 h was enough to inactivate all specimens, up to a concentration of 0.06375. The histological analysis, observed the accumulation of liquid in the tegument in the specimens incubated in C. aurantium and P. graveolens, with vacuolization in the tegument and spines, preventing externalization. The results of the study present OEs with efficient ovicidal and adulticidal activity.
片形吸虫病是动物健康中最重要的寄生虫病之一，主要影响反刍动物，导致经济和生产力损失。本研究旨在评估 Pelargonium graveolens（天竺葵）和 Citrus aurantium（酸橙）精油（EOs）对 Fasciola hepatica 的体外杀卵和成虫活性。对 P. graveolens 和 C. aurantium 的 EO 进行气相色谱分析，其主要化合物分别为香茅醇（31.37%）和柠檬烯（93.89%）。对于细胞毒性测定，当使用较低浓度时，酸橙 EO 显示出有希望的结果。对于杀卵试验，将虫卵与天竺葵 EO 在 4.5 至 0.03375 mg/mL 浓度下孵育，与对照一起。在孵育后第 14 天计数存活的卵。将 F. hepatica 的成虫形式与 EO 一起孵育，并在处理后 24 小时观察，以及对照。随后将标本固定用于组织学分析。在测试浓度下，天竺葵和酸橙 EO 对未处理对照的虫卵孵化具有 100%的有效灭活作用（p<0.05）。在成虫致死试验中，在测试的两种浓度（0.0675 和 0.03375）下，P. graveolens 的精油在 15 小时内促进了吸虫的死亡。对于 C. aurantium，在 0.06375 浓度下，18 小时足以使所有标本失活。组织学分析观察到在孵育于 C. aurantium 和 P. graveolens 的标本中，在表皮中积累液体，表皮和棘突出现空泡化，阻止了外化。研究结果表明 OEs 具有有效的杀卵和成虫活性。
