CHEMICAL PROFILE AND LARVICIDAL POTENTIAL AGAINST AEDES AEGYPTI OF MENTHA PIPERITA ESSENTIAL OIL MICROCAPSULES

Objective: This study aimed to characterize the chemical composition of Mentha piperita essential oil and evaluate the larvicidal activity of its alginate microcapsules against Aedes aegypti larvae. Methods: The essential oil was extracted by hydrodistillation and analyzed by GC-MS. Microcapsules were prepared by ionic gelation using sodium alginate as wall material and calcium chloride as crosslinking agent. Larvicidal activity was assessed against third and fourth instar larvae of Aedes aegypti using the microdilution method, with mortality rates recorded after 24 hours of exposure. Results: GC-MS analysis identified five major compounds, with menthol (55.95%) as the predominant constituent, followed by menthone (20.74%), eucalyptol (10.44%), menthyl acetate (8.52%), and trans-menthone (4.35%). The microencapsulated essential oil exhibited significant larvicidal activity, with an LC₅₀ value of 15.66 ± 1.85 mg/L and a high coefficient of determination (R² = 0.9991), indicating a strong correlation between concentration and mortality. The observed larvicidal effect is attributed to the high menthol content and the synergistic action of oxygenated monoterpenes, which act by disrupting the larval cuticle and interfering with the nervous system. Conclusion: M. piperita essential oil microcapsules present a promising larvicidal profile against Aedes aegypti, offering a biodegradable, selective, and low-cost alternative for vector control. These findings position the microencapsulated essential oil as a potential candidate for the development of plant-based larvicides, contributing to the reduction of arbovirus transmission.