Indonesian Black Tea (Camellia sinensis) as a Potential Acetylcholinesterase Inhibitor Against Alzheimer’s Disease: Docking, DFT, and In Vitro Evidence

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder predominantly affecting the elderly and characterized by dementia. AD pathology involves impaired cholinergic neurotransmission, largely due to β-amyloid (Aβ) plaque accumulation, which inhibits choline acetyltransferase (ChAT) and reduces acetylcholine (ACh) levels. Acetylcholinesterase (AChE) contributes to AD progression by hydrolyzing ACh and promoting Aβ plaque formation, making it a key therapeutic target. This study investigated natural compounds from black tea (Camellia sinensis) as potential AChE inhibitors. Molecular docking analyses assessed interactions between bioactive compounds from aqueous black tea extracts and AChE, followed by evaluation of bioavailability, biological activity, toxicity, stability, and reactivity. Epigallocatechin gallate exhibited the strongest binding affinity (∆Gbind = –12.2740 kcal/mol), forming extensive interactions with the catalytic active site located at the bottom of a deep and narrow gorge (~20 Å). Density Functional Theory (DFT) analysis confirmed its high stability and favorable reactivity in complex with AChE. In vitro validation using black tea extracts from Bogor, Indonesia, showed significant AChE inhibition with an IC50 value of 44.85 ± 1.48 µg/mL. These findings highlight the promising potential of Indonesian black tea as a natural alternative for Alzheimer’s disease therapy.