Ageratina adenophora essential oil: A promising miticidal agent against Sarcoptes scabiei, and its effects on key enzymatic pathways

Abstract

The common scabies mite, Sarcoptes scabiei (S. scabiei) is a cosmopolitan parasite of humans and other mammals. This study evaluated the potential of Ageratina adenophora (A. adenophora) essential oil (EO) to serve as a synergist for enhancing biological control agents against scabies by investigating its acaricidal activity and underlying mechanism. 52 components (99.6 %) were identified by GC–MS. The major components included bornyl acetate (11.16 %), β-bisabolene (9.34 %), cymene (8.17 %), γ-curcumene (8.10 %), and β-caryophyllene (8.05 %). In vitro, it showed good contact toxicity, fumigation activity, and repellency against S. scabiei. At 40 mg/mL for 2 h, the contact mortality, fumigation mortality and repellent rates were 100 %, 100 %, and 92 %, respectively. Medium lethal concentration (LC₅₀) values for contact toxicity and fumigation activity at 2 h were 27.132 mg/mL and 12.579 mg/mL. In vivo, cure rates at 20, 10, 5 mg/mL were 100 %, 100 %, 83.3 % in rabbits, with no skin irritation at 200 mg/mL. Enzyme tests showed that SOD increased first, then decreased, GST was activated, AchE, Na⁺-K⁺-ATP, and Ca²⁺-Mg²⁺-ATP were inhibited. The significant activity of A. adenophora essential oil both in vitro and in vivo, along with its ability to disrupt key physiological processes in mites, supports its potential as a synergist to enhance the efficacy of biological control agents against scabies mites. Additionally, the observed safety profile at certain doses further encourages its exploration as a component within integrated pest management strategies.