Development and characterization of an eco-friendly plant extract-loaded nanoemulsion for pest control

Phyma leptostachya is a traditional insecticidal plant that has been employed as a natural insecticide for the control of various pests. Nanotechnology possesses transformative potential in the field of crop protection and contributes to the optimal utilization and outstanding performance of plant extracts. Hence, the preparation process of P. leptostachya extract-loaded nanoemulsions was investigated in this study, as well as the aphicidal activity and safety to non-target organisms.

Nanoemulsion formulated with the emulsifier EL-60 demonstrated superior stability. Furthermore, the stability of these nanoemulsions was found to enhance with increasing emulsifier concentrations, ranging from 1% to 5%. The optimized formulation of nanoemulsion was formed as follows: 0.2% P. leptostachya extract, 2% S-200, 3% EL-60, and 94.8% deionized water. Finally, P. leptostachya extract-loaded nanoemulsion showed excellent insecticidal activity against Acyrthosiphon pisum with LC₅₀ 0.2267 mg/mL at 24 h. The LC₅₀ of nanoemulsion to earthworm was much higher than 10 mg/kg dried soil, indicating nanoemulsion has good safety. In addition, nanoemulsion had no effect on the plant height of Vicia faba and bolster its antioxidant systems.

This research has enabled the design and fabrication of nanoemulsions loaded with P. leptostachya extract, which serve as a novel insecticide aimed at enhancing insecticidal efficacy with low toxicity that is beneficial to the sustainable control of pests. © 2025 Society of Chemical Industry.