Cellulose filter paper immobilized acetylcholinesterase for rapid screening of enzyme inhibitors in Phyllanthus emblica L.

Abstract

Acetylcholinesterase (AChE) is widely recognized as a promising therapeutic target enzyme for Alzheimer's disease (AD). The screening of AChE inhibitors (AChEIs) holds great significance for the treatment of AD. In this study, cellulose filter paper (CFP) -immobilized AChE was prepared and firstly applied to screening AChEIs from 30 % ethanol extract of Phyllanthus emblica L. fruits combined with ultra-high performance liquid chromatography quadrupole time-of-fight mass spectrometry (UHPLC-Q-TOF-MS/MS). Using CFP-immobilized AChE as the bait, AChEIs were harvested and the instantaneous separation characteristics of CFP were utilized to further facilitate the separation of the complex from the inactive components. Ultimately, 27 compounds specifically bound with AChE were screened and identified using UHPLC-Q-TOF-MS/MS. Additionally, molecular docking was employed to explore the binding mechanisms between screened potential inhibitors and AChE. The results show that, most of the screened compounds were found to exhibit higher affinity that of the positive control (huperzine A), and all the compounds expect mucic acid to be well embedded into the active pocket of AChE. To verify the reliability of the screening method and molecular docking, two commercial standards geraniin and ellagic acid were experimented with an AChE inhibition assay in vitro. The results showed that both compounds were found to effectively inhibit AChE with IC₅₀ values of 42.42 ± 7.10 μM, 172.43 ± 9.22 μM. The developed method exhibits the advantages of rapidness and effectiveness in screening of AChEIs from complex herbal extracts.