Acaricidal activity of Laurus nobilis L. against Varroa destructor: nanoemulsion and molecular docking

Varroa destructor (Acari: Varroidae) is one of the most significant threats to honeybee health, and sustainable alternatives to synthetic acaricides are urgently needed. Essential oil (EO)-based nanoformulations have emerged as promising candidates due to their enhanced stability and bioavailability.

In this study, the acaricidal effect of a nanoemulsion (NEms) of Laurus nobilis L. EO was evaluated through field trials. The chemical composition of the oil was analyzed by gas chromatography-mass spectrometry (GC-MS), and the physicochemical properties of the NEms were characterized. Additionally, molecular docking analysis was performed to investigate interactions between major components and acetylcholinesterase (AChE).

GC-MS analysis revealed 1,8-cineole (40.65%) as the main component, followed by α-terpinyl acetate and β-phellandrene. The NEms exhibited a mean droplet size of 72.36 nm with good stability. Field results demonstrated a dose-dependent reduction in mite density, reaching 70.3% efficacy at 200 ppm, compared to 40.2% for the positive control (flumethrin). Molecular docking showed strong binding interactions with AChE, with α-terpinene exhibiting the highest affinity (-6.874 kcal/mol), followed by 1,8-cineole (-6.163 kcal/mol).

These findings indicate that L. nobilis NEms may represent an effective and environmentally friendly alternative for controlling Varroa mites, supported by a plausible neurotoxic mechanism. To our knowledge, this study is among the first to integrate NEms -based field efficacy with AChE-targeted molecular docking, linking biological activity with mechanistic insight.