Acetylcholinesterase inhibition activity and phytochemical screening of red betel leaf (

\nAlzheimer's Disease (AD) is a neurodegenerative condition that results in progressive cognitive deterioration. The AD therapeutic approach with acetylcholinesterase inhibitors aims to boost cognitive function by raising acetylcholine levels in synaptic neurons. Piper crocatum Rui & Pav has antioxidant and anti-inflammatory properties, suggesting its potential to alleviate AD symptoms. This research aims to investigate the inhibitory activity of acetylcholinesterase (AChE) in vitro and identify the active compounds present in the fractions of red betel leaf. The methods of this research are Ellman’s colorimetric method and Liquid Chromatography-Mass Spectrometry (LC-MS). The red betel leaf fractions demonstrated effective AChE inhibition, as reflected by their IC50 values: 11.0965 μg/ml (ethanol extract), 16.7908 μg/ml (ethyl acetate fraction), 23.7390 μg/ml (n-hexane fraction), and 41.0044 μg/ml (water fraction). The ethanol extract with the lowest IC50 value was analyzed by LC-MS. The result showed 200 active compounds, 28 of which had concentrations exceeding 0.5%. The predominant active compounds include flavonoids, steroids, polyphenols, alkaloids, phenolics, vitamins, and carboxylic acids. In conclusion, the ethanol extract of red betel leaf shows promising potential as an AChE inhibitor, suggesting its use as a therapeutic agent to enhance cognitive function in patients with Alzheimer's Disease.\n