Essential oil from Pterodon emarginatus as a promising natural raw material for larvicidal nanoemulsions against a tropical disease vector

- Pterodon emarginatus fruits is a great source of an essential oil.
- Sustainable use of this non-timber forest natural product is very promising.
- Ecofriendly green nanoemulsion was prepared for Aedes aegypti control.
- No organic solvent or heating step was used in the process.

The oleoresin obtained from fruits of Pterodon emarginatus was previously subjected to development of larvicidal nanoemulsions. To our knowledge, no efforts aiming at developing nanoemulsions with the essential oil from this species were carried out. This study describes the preparation and evaluation of the larvicidal activity of a novel oil in water nanoemulsion prepared with essential oil from fruits of P. emarginatus against Aedes aegypti larvae. β-caryophyllene is the major compound, corresponding to 25.8% of relative percentage of the essential oil. A series of nanoemulsions were obtained and better physical results were achieved using polysorbate 80, suggesting that a required Hydrophile-Lipophile balance value of this oil is around 15. Mean droplet size decreased from 128.0 ± 6.2 nm to 53.2 ± 0.5 nm, when surfactant to oil ratio increased from 1.0 to 2.0. The nanoemulsion prepared with P. emarginatus essential oil and polysorbate 80 (1:1) was able to induce mortality on early 4th instar larvae. This study allowed preparation of nanoemulsions with essential oil from fruits of P. emarginatus for the first time, which proved to be a potential larvicidal against Aedes aegypti. The utilization of a low cost and solvent-free method can be considered an advantage in terms of potential applications of this natural product in ecofriendly integrative practices of vector control. Moreover, the great potential of this plant species is highlighted by the fact that its fruits can be obtained by a sustainable management of biodiversity, using the concept of standing trees to protect and stimulate conservation of the species.

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