Abstract
Background:
The management of helminthiasis remains a significant challenge in clinical and veterinary practice because the most important parasites have acquired extensive drug resistance in animal infections and reduced efficacy in human conditions. The toothache plant (Acmella oleracea) is a medicinal plant used in the Mizo traditional system of India for deworming intestinal parasites in both humans and domesticated animals. Therefore, it is important to understand the bioactive components and biological effects of the plant.

Aim:
Experiments were set up to characterize the bioactive compound of the plant and assess its antiparasitic activity against intestinal cestodes and nematodes.

Methods:
The aerial parts of the plants were extracted with hexane in a Soxhlet apparatus. The extract was concentrated and fractionated using column chromatography. The elution was performed with n-hexane and ethyl acetate. The major compound was characterized by thin-layer chromatography (TLC) and gas chromatography-mass spectrometry (GCMS). The antiparasitic activity was evaluated against parasitic cestodes and nematodes of the chicken intestine. The antiparasitic effects were studied by scanning electron microscopy.

Results:
A single compound was eluted from column chromatography as indicated by TLC at an Rf value of 0.56 from a mobile phase consisting of 0.1% ethyl acetate in n-hexane. GC-MS data showed that the isolated compound exhibited the chemical properties of lupeol (fagarasterol). This is the first report on lupane-type pentacyclic triterpene isolated from a toothache plant. The compound was effective against both cestode and nematode. Scanning electron microscopy revealed hallmark anthelmintic effects on the parasites. Distortion of the tegument, destruction of the suckers, and removal of spines were noted for the cestode; while fracture of the mouth region, loss of sensory papillae, and deflation of the cuticle throughout the body were observed on the nematode.

Conclusion:
This study presents a showcase of the isolation of lupeol from the toothache plant and demonstrates the utility of the compound as a broad-spectrum antiparasitic molecule against cestodes and nematodes. The findings of this study encourage further investigations of the mode of action, molecular interactions, and other pharmacological properties of the compounds for drug development.

Key words: Cestode, Chromatography, Medicinal plant, Nematode, Scanning electron microscopy