Chemical Composition, Acetylcholine Esterase and Anti-bacterial Activities of Essential Oils of Elaeosilenum thapsioides (Desf.) Maire from Algeria

Background: Traditionally, the Algerian medicinal plantElaeosilenum thapsioides (Desf.) Maire has been used for many diseases. The present research work aims to explore the chemical and biological characterization of its essential oil. Methods: The essential oils were obtained by hydrodistillation of differentElaeosilenum thap-sioides (Apiaceae) aerial parts samples collected from two different regions (Mahouane and Me-gres) from Setif, Eastern Algeria. The chemical characterization of the obtained essential oils is re-ported here for the first time. Besides, they were evaluated for theirin vitro Acetylcholinesterase (AChE) inhibitory activity involved in Alzheimer's disease using Ellman's spectrophotometric method. Results: Additionally, theirin vitro antimicrobial activity was assessed by the disc diffusion method. Both activities were performed at various oil concentrations. The GC/MS analysis of the essential oils from aerial parts (leaves, stems, flowers, and seeds) ofE. thapsioides identified 47 constituents. Monoterpene hydrocarbons were the main components, ranging from 72.78 99.13%. Oxygenated monoterpenes and oxygenated sesquiterpenes ranged between 1.37 and 17.25% and 0.12 and 3.53% in essential oils from leaves and stems. Sesquiterpene hydrocarbons were present in small to large quantities in the essential oils of both populations, ranging from 0.69 to 13.44%. The presence of m-Methoxybenzyl isothiocyanate was recorded in stems essential oils from Mahouane and leaves essential oils from Merges, which was 9.73% and 3.72%, respectively. Conclusion: The stems essential oils obtained from plants collected in Mahouane showed the high -est AChE inhibitory activity. The highest anti-bacterial activity was shown by the essential oil ob-tained from Megres leaves against Bacillus cereus ATCC 11778. The oils exhibited a moderate in-hibitory activity in both tests