<![CDATA[Alzheimer's disease is a progressive neurodegenerative disorder in which cholinergic decline is managed mainly with acetylcholinesterase (AChE) inhibitors, yet the available drugs are limited by adverse effects and modest benefit. Natural products are therefore explored as alternative sources of inhibitors. This study aimed to systematically review the evidence on bioactive compounds from natural sources as AChE inhibitors for Alzheimer's therapy. Twenty scientific articles published between 2020 and 2026 were reviewed qualitatively, consisting of nine primary studies (molecular docking, in vitro enzyme assays, and combined approaches) and eleven review articles. Data on the tested materials, methods, and main findings were extracted and compared across studies. The primary studies showed that several compounds, such as chrysophanic acid, epigallocatechin gallate, gedunin, and astragalin, had favorable docking scores against AChE, whereas crude plant extracts displayed only moderate inhibition in vitro compared with the reference inhibitor. The reviews indicated that alkaloids, flavonoids, terpenoids, and marine metabolites are the main classes with anticholinesterase potential, frequently accompanied by antioxidant and anti-inflammatory effects. However, most of the evidence remains computational or preclinical, and pharmacokinetic and toxicity data are scarce. Natural bioactive compounds are promising AChE inhibitor candidates, but they require further experimental validation and preclinical development.]]>
