Pimpinella anisum Essential Oil Nanoemulsion Toxicity against Tribolium castaneum? Shedding Light on Its Interactions with Aspartate Aminotransferase and Alanine Aminotransferase by Molecular Docking

The insecticidal activity is the result of a series of complex interactions between toxic substances as ligands and insect's enzymes as targets. Actually, synthetic insecticides used in pest control programs are harmful to the environment and may affect non-target organisms; thus, the use of natural products as pest control agents can be very attractive. In the present work, the toxic effect of aniseed (Pimpinella anisum L.) essential oil (EO) and its nanoemulsion (NE) against the red flour beetle Tribolium castaneum, has been evaluated. To assess the EO mode of action, the impact of sub-lethal concentrations of aniseed EO and NE was evaluated on enzymatic and macromolecular parameters of the beetles, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), total protein, total lipids and glucose. Finally, a molecular docking study was conducted to predict the mode of action of the major EO and NE components namely E-anethole, Limonene, alpha-himalachalene, trans-Verbenol and Linalool at binding site of the enzymes AST and ALT. Herein, the binding location of the main compounds in both proteins are discussed suggesting the possible interactions between the considered enzymes and ligands. The obtained results open new horizons to understand the evolution and response of insect-plant compounds interactions and their effect predicted at the molecular levels and side effects of both animal and human.