Evaluation of the mosquito repellent action of cuban oregano (Plectranthus amboinicus) essential oil

Abstract

This project was mainly on the evaluation of the repellency of Cuban Oregano (Plectranthus amboinicus) essential oil against the mosquitoes. A chamber designed by using AutoCAD software was used to evaluate the repellent ratio of the mosquitoes. The material used to fabricate the chamber was acrylic plastic. The chamber was divided into three sections, which were treated chamber, untreated chamber and released chamber. The Cuban Oregano essential oil was extracted by the soxhlet extraction method using three different solvents, that were hexane (first stage), chloroform (second stage) and methanol (third stage). The repellent ratios of each stage of extracted essential oils were evaluated by the number of distribution of mosquitoes in the treated and untreated chamber. Total phenolic in the essential oil was measured by UV-vis spectrometry. Second stage extraction of Cuban Oregano essential oil using chloroform resulted the highest repellent ratio when evaluated with twenty mosquitoes in the chamber and compared with hexane and methanol extraction. This essential oil also contained the highest total phenolic content and can be considered the most effective essential oil to repel mosquitoes.