Abstract
Senecio brasiliensis is a toxic plant from the Asteraceae family, known to contain bioactive compounds with pharmacological and toxicological potential. This study aimed to investigate the toxicity of Senecio brasiliensis essential oil with in silico and in vivo approaches, using Drosophila melanogaster as the experimental model. The plant was collected, identified and the essential oil extracted from leaves and flowers using hydrodistillation with a Clevenger apparatus. Phytochemical analysis was performed using Gas Chromatography-Mass Spectrometry (GC-MS). Negative geotaxis assay and acetylcholinesterase activity were conducted at 24, 48 and 72 h, along with 144 h survival rate assessment, using different concentrations of the essential oil (3, 30 and 300 μg/mL). Molecular docking analysis was also conducted to assess interactions between the major constituents of the oil with acetylcholinesterase and D. melanogaster cholinergic receptors. Phytochemical analysis resulted in 100% identification of the oil's constituents, notably, bicyclogermacrene (23.36%) and germacrene-D (21.58%) were the major constituents. There was a trend of increased locomotion and a lower acetylcholinesterase activity with 30 and 300 μg/mL of the essential oil. There was also a significant decrease in the 144 h survival rate of the 3 μg/mL group. In silico analysis revealed interactions of major constituents with acetylcholinesterase and both muscarinic and nicotinic receptors. Particularly in B chain of muscarinic receptors, with binding energies of -6.7 kcal/moL for bicyclogermacrene and - 7.6 kcal/mol for germacrene-D. These results may provide insights into the biological effects of the Senecio brasiliensis essential oil and its potential as a bioactive compound.