Synthesis, characterization and insecticidal activity of Mentha spicata essential oil loaded polymeric nanoparticles

Abstract

Chemical insecticides are often employed to manage stored grain pests. However, their use could have severe consequences for consumers and the environment. Thus, nanotechnology could present intriguing answers to issues related to agricultural and the food sectors. In the present investigation, Mentha spicata essential oil (MsEO) loaded chitosan nanoparticles (MsEO/CSNPs) were synthesized and characterized using FTIR, SEM, TEM, DLS and XRD. It was observed that the average size of the nanoparticles ranged between 50 and 200 nm with 0.428 and 0.222 PDI for the MsEO loaded chitosan nanoparticles (MsEO/CSNPs1) and MsEO loaded chitosan nanoparticles (MsEO/CSNPs2), respectively. SEM and TEM studies revealed spherical nature of the nanoparticles. Loading Capacity (LC) was found to be 6.62–4.19% and encapsulation efficiency (EE) ranged from 79.5 to 82.5% in MsEO/CSNPs1 and MsEO/CSNPs2. Further, MsEO-loaded chitosan nanoparticles (MsEO/CSNPs1 and MsEO/CSNPs2) demonstrated excellent antioxidant activity with IC50 values of 24.2 μg/mL and 30.9 μg/mL, suggesting that MsEO/CSNPs might be employed for an effective natural antioxidant agent. The synthesized MsEO/CSNPs showed strong insecticidal efficacy when used for Callosobruchus maculates (LC50 56 μL/L) and Sitophilus granaries (LC50 47 μL/L) in toxicity tests. These nanoparticles were also tested for cytotoxicity on the Vero cell line, and the results revealed that they were nontoxic. The findings demonstrate that Mentha spicata essential oil (MsEO) loaded chitosan nanoparticles (MsEO/CSNPs) is an innovative development that might be used in a food storage pest control strategy for Callosobruchus maculatus and Sitophilus granaries.