Evaluation of the scolicidal activities of eugenol essential oil and its nanoemulsion against protoscoleces of hydatid cysts

Abstract

Background Cystic echinococcosis caused by the cestode Echinococcus granulosus remains a serious helminthic zoonosis affecting humans and animals in many endemic developing countries. Surgical intervention is the best management choice, although it is associated with high recurrence rates and serious complications. Also, the commonly used chemotherapeutics exhibited serious side effects. This study aimed to evaluate the protoscolicidal effects of eugenol (Eug) essential oil and its nanoemulsion (Eug-NE) against protoscoleces (PCs) of hydatid cysts in vitro. Methods Eug-NE was prepared and characterized. Their cytotoxicity on macrophages was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. E. granulosus PCs were treated with various concentrations of Eug and Eug-NE at different exposure times. The viability of protoscoleces was evaluated by the eosin exclusion test, and the changes in the morphology of protoscoleces were assessed. Albendazole (ABZ) was used as a positive control. Results The cellular cytotoxicity of Eug and Eug-NE on macrophage cells, in minimum and maximum concentrations (0.2 and 1 μl/mL), were nearly negligible ranging from 4.7% to 8.3% and 3.7% to 7.2%, respectively. The results showed highly significant activity of Eug-NE and Eug against hydatid PCs compared to ABZ (P < 0.05). Eug and Eug-NE have similar protoscolicidal effects at all used concentrations. Their highest scolicidal activity (100% mortality rate) was recorded at 1 μl/ml after 30 min incubation (LC50 = 0.298—LC90 = 0.521 and LC50 = 0.309—LC90 = 0.646, respectively). Both formulations showed time- and dose-dependent effects. Conclusions This study suggested the potent scolicidal activities of Eug and Eug-NE as promising alternative scolicidal agents. Future studies are recommended to explore the mechanism of action and treatment response in vivo and clinical settings.

Eugenol Essential Oil and Nanoemulsion as Antihydatic Agents with Antifibrotic and Immunomodulatory Effects in Cystic Echinococcosis

“…Based on the promising scolicidal effects of Eug and its nanoemulsion against protoscoleces of hydatid cysts observed in a previous study [ 31 ], this study investigated the antihydatic properties of both preparations in a murine model.…”

“…Eug-NE was prepared and characterized using the high-pressure homogenization method The preparation technique and characterization methods for the assessment of Eug-NE were described in detail in a previous in vitro study published by the authors [ 31 ]. Briefly, the average particle size and the polydispersity index (PDI) values of Eug-NE were 65 ± 11.11 nm and 1.00, respectively, as determined by the Zetasizer.…”

“…Protoscoleces were aseptically collected from the liver and lung hydatid cysts isolated from infected camels slaughtered in Bani-Adi and El-Atamina abattoirs, Assiut Governorate, Egypt, as described previously [ 31 ]. The viability of PSCs was tested before inoculation by the eosin exclusion test.…”

“…As Eug oil and its nanoemulsion showed a profound scolicidal effect [ 31 ], besides its well-known immunostimulatory effect in enhancing the Th1 immune response, which could be protective against CE progression [ 40 ], this study was designed to gain insight into the antihydatic effects of Eug oil and its nanoemulsion in a CE murine model, with a particular focus on their immunomodulatory properties.…”

“…Therefore, several researchers studied their antiparasitic properties; however, the antimicrobial and antiparasitic applications of Eug nanoemulsion were less investigated in only a few studies as an antimicrobial agent and a larvicide [29,30]. In addition, a recent in vitro study has suggested that eugenol (Eug) oil and its nanoemulsion showed promising protoscolicidal properties, with high safety and efficacy [31].…”