Toxicity of geranium oil, geraniol and their nanoemulsions on protoscoleces of hydatid cyst under in vitro conditions

Abstract

Surgery is the main efficacious treatment for many cases of cystic echinococcosis by removing Echi-nococcus granulosus cysts. However, to reduce risk of cyst spillage and insemination of the content, using a scolicidal agent is crucial. Considering side effects of available scolicidals, and growing nano-technological approaches in novel pharmaceuticals, the present study aimed to find out the scolicidal activity of geraniol (GL), geranium oil (GM), and their developed nanoemulsions (Nano-GL and Nano-GM) on the protoscoleces of E. granulosus. Nanoemulsions were developed by ultrasonication emulsification and characterised by dynamic light scattering method (DLS). The scolicidal effect of GL, GM, Nano-GL, and Nano-GM at different concentrations of 1, 2.5, 5, 10, 25, and 50 µg/mL were determined after 0.5, 1, and 2 hours of incubation. Mortality rates were measured by eosin exclusion test. The average droplet size for Nano-GM and Nano-GL were 124.8 and 88.59 nm, respectively. After one hour of exposure, all tested concentrations of GL and Nano-GL resulted in higher than 90% mortality rates, while GM and Nano-GM killed 70.66% and 90.33% of protoscoleces, respectively. Based on 50% lethal concentration, Nano-GL was significantly more potent than Nano-GM (LC50: 4.52 vs 102.95 μg/mL). Results of scanning electron microscopy revealed tegumental disruption in the treated protoscoleces. This study described an easily applicable and eco-friendly procedure of nano-formulating functional phytochemicals, showing promising scolicidal activity in vitro. The developed formulations, especially Nano-GL, showed the characteristics of an ideal scolicidal agent. Further studies are needed to assess in vivo efficacy and safety of this formulation.

Keywords

• cystic echinococcosis
• green drugs
• nanotechnology
• phytochemicals