In silico investigation and experimental validation of pistagremic acid isolated from Pistacia integerrima against Rhipicephalus microplus and Sarcoptes scabiei.

Rhipicephalus microplus and Sarcoptes scabiei are major ectoparasites affecting both humans and animals, causing significant economic losses to the dairy and agricultural sectors. This study aimed to evaluate the in vitro and in silico efficacy of pistagremic acid (PA), a natural compound isolated from Pistacia integerrima, against these parasites. Different concentrations of the compound were tested using the adult immersion test (AIT) and larval packet test (LPT) to assess their in vitro effects on mites and various tick life stages. Molecular docking was conducted to examine the interactions of PA with glutathione S-transferases (GSTs) of S. scabiei and R. microplus proteins. The results demonstrated high in vitro acaricidal activity, with significant efficacy in both AIT and LPT assays. In silico studies identified PA as a key bioactive compound, showing strong binding interactions with S. scabiei GST (binding energy: 10.0 kcal/mol) compared to permethrin (-8.1 kcal/mol) and with R. microplus GST (docking score: 7.8 kcal/mol) compared to ivermectin (-8.3 kcal/mol). Overall, PA shows strong potential as a plant-derived alternative for managing tick and mite infestations, supporting its further exploration as a novel acaricidal agent.