Essential oil constituents as ecdysone receptor ligands of pest insects: in silico approach with autodock vina

Abstract

The search for alternatives to the insect pest control has become a major global worry. These factor added to climate change may affect severely the agricultural production. Synthetic chemicals have been used as a system of control of these types of insects, although their application has raised various concerns including environment and human health damage. Nevertheless, the use of natural compounds, primarily those derived from plants like essential oils have been proposed as alternative for this purpose. Some authors have proposed different protein targets, among them chitin synthase, nicotinic acetylcholine receptor (nAChR), gamma-amino butyric acid (GABA) receptor and ecdysone receptor (EcR). However, the biochemical mechanisms responsible of their insecticide action are still lacking information. In this work, 47 constituents of essential oils were evaluated in silico in order to identify potential agonist of the ecdysone receptor to four pest insect species (Bemisia tabaci; 1Z5X, Tribolium castaneum, 2NXX, Heliothis virescens; 2R40, Helicoverpa armigera; 3IXP) using molecular docking protocols with AutoDock Vina 1.1 program. The results showed that essential oils constituents such as Camphorene, Kaur-16-ene, Pimara-7,15-dien-3-one, Pimara-7,15-dien-3-ol, Virifidol produced promising theoretical affinity values (between -8.2 to -8.8 kcal/mol) taking as reference the mean affinity value (-8.2 kcal/mol) obtained for eleven EcR LBD agonists with biological activity reported in the literature. AutoDock Vina affinities scores for several EcR LDB active compounds on the four different structures evaluated, found that only for H. virescen (PDB: 2R40) showed a significant linear correlation (r = 0.688, p-value <0.028) for theoretical affinity values and biological activity data, supporting the computational reliability of the predictions made by our docking simulations. Theoretical approaches suggest that these constituents of essential oils may be applied as possible natural insecticide agents and will provide a platform for structure-based design of stronger and selective insecticides with a lower risk to the environment and humans.