Fe3O4@MXene@PEI aerogel immobilized acetylcholinesterase for inhibitor screening from herbal plants

Screening of acetylcholinesterase (AChE) inhibitors is a common strategy in drug discovery for treating Alzheimer’s disease. Herein, AChE was immobilized onto magnetic polyethyleneimine-based MXene aerogels through both electrostatic interactions and covalent bonds, enabling its application in AChE activity assays and inhibitor screening of herbal plants. The composite was analyzed using a range of techniques, including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and Zeta potential analysis, to gain insight into its chemical and physical properties. The proposed Fe₃O₄@MXene@PEI-AChE composite exhibited enhanced temperature and pH stability, as evaluated by Ellman’s method, along with good reusability. The Michaelis Menten constant (K_m) of the immobilized AChE was calculated to be 0.68 mmol/L. Additionally, an inhibition kinetic study was conducted to verify the feasibility of utilizing the immobilized enzyme to screen for inhibitors, with huperzine A employed as a model inhibitor. The proposed strategy was employed to compare the AChE inhibitory activity of 18 commonly used herbal medicines for treating AD, revealing both the aqueous and alcoholic extracts of Coptis chinensis as exhibiting the highest AChE inhibitory activity. Finally, the screening of AChE inhibitors in Coptis chinensis extracts were conducted by combining the proposed strategy with UPLC-Q-Orbitrap high resolution mass spectrometry. This study presents a feasible strategy for monitoring AChE activity and holds considerable potential for further exploration of AChE-inhibiting active ingredients in herbal medicines.