In Vitro Bioassay and In silico Pharmacokinetic Characteristics of Xanthium strumarium Plant Extract as Possible Acaricidal Agent

Background: Effective management strategies against tick infestations are necessary because tickborne diseases represent serious hazards to the health of humans and animals worldwide. The aim of this study was to examine the larvicidal and ovicidal properties of Xanthium strumarium extract against a notorious tick species, Rhipicephalus microplus.

Methodology: The maceration method was used to prepare the ethanolic extract of X. strumarium. The extract was then used in an adult immersion test (AIT) and larval packet test (LPT) to asses the plant's toxicity. To elucidate the mode of action, molecular modeling and docking studies were conducted. ADMET analysis was then carried out to find out the drug-likeness profiles of the plant phytochemicals.

Results: Significant death rates and egg inhibition were found at different extract doses using the larval packet test (LPT) and adult immersion test (AIT). A concentration-dependent impact was observed at a concentration of 40 mg/mL, which resulted in the maximum larval mortality (92 ± 2.646) and egg inhibition (77.057 ± 2.186). Additionally, the potency of the extract against R. microplus was determined by calculating its fatal concentrations (LC50, LC90, and LC99). A three-dimensional model of the R. microplus octopamine receptor was created, and docking studies showed that the receptor and possible ligands, most notably Xanthatin and Xanthosin, interacted well. The potential of compounds as tick control agents was highlighted by their pharmacokinetic characteristics and toxicity profiles, as revealed by drug-likeness and ADMET studies. Molecular dynamic simulations further demonstrated the stability of the protein-ligand complex, indicating the consistent association between the ligand and the target protein.

Conclusion: Overall, this study provides valuable insights into the potential use of X. strumarium extract and its compounds as larvicidal and ovicidal agents against R. microplus, paving the way for further research on tick control strategies.