Phytochemical profiling of Olea europaea subsp. cuspidata aerial parts using LC-DAD-QToF: cholinesterase inhibition and molecular docking insights into potential Alzheimer’s disease targets

Abstract

Olea europaea subsp. cuspidata is traditionally used in African medicine, but its phytochemical composition and cholinesterase inhibitory activity have not been comprehensively investigated. This study evaluated the cholinesterase inhibitory activity and phytochemical profile of the methanolic extract of O. europaea aerial parts, integrating in vitro assays with LC-DAD-QToF-MS characterisation and molecular modelling. We used the Ellman assay to measure cholinesterase inhibition and LC-DAD-QToF-MS for metabolite profiling, while molecular docking and dynamics simulations helped us understand how specific metabolites interact with human acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The extract inhibited AChE (IC50 = 15.99 ± 1.62 μg/mL) to a greater extent than BChE (IC50 = 22.62 ± 2.20 μg/mL). LC-DAD-QToF-MS allowed the tentative identification of 65 metabolites, comprising iridoids, phenylethanoids, flavonoids, phenolic acids, terpenoids, fatty acids, and one alkaloid. Computational predictions support potential interactions only between constituents within the enzyme active sites but do not establish biological activity. These results offer the first detailed phytochemical profile of the aerial parts of O. europaea and confirm its in vitro cholinesterase inhibitory activity. Bioactivity-guided isolation and in vivo studies are required to pinpoint the metabolites responsible for the observed effects and to establish their therapeutic relevance.