Differential inhibition of human erythrocyte acetylcholinesterase by polyphenols epigallocatechin‐3‐gallate and resveratrol. Relevance of the membrane‐bound form

Abstract

The activity of acetylcholinesterase (AChE) from human erythrocytes was tested in the presence of the phenolic compounds resveratrol and epigallocatechin-3-gallate (EGCG). Even though the stilbene barely changed this enzymatic activity, EGCG did inhibit AChE. Importantly, it preferentially acted on the membrane-bound enzyme rather than on its soluble form. Actually, it was shown that this flavonoid may bind to the red blood cell membrane surface, which may improve the interaction between EGCG and AChE. Therefore, caution should be taken when screening AChE inhibitors. In fact, testing compounds with the soluble form of the enzyme may underestimate the activity of some of these potential inhibitors, hence it would be advisable not to use them as a sole model system for screening. Moreover, erythrocyte AChE is proposed as a good model for these enzymatic assays. © 2016 BioFactors, 43(1):73-81, 2017.

Interaction of Catechins with Human Erythrocytes

“…Although the function of acetylcholinesterase on the erythrocyte surface remains a mystery, this membrane-bound enzyme is very useful for model studies of acetylcholinesterase inhibitors. Inhibition of erythrocyte membrane acetylcholinesterase by EGCG has been reported [41,42], although the kinetic aspects of this inhibition have not been reported to our best knowledge. Our results pointed to a mixed-type inhibition of erythrocyte membrane acetylcholinesterase activity by EGC and EGCG.…”

Cholinesterase targeting by polyphenols: A therapeutic approach for the treatment of Alzheimer’s disease

“…The specific AChE inhibitory activity noted by these hybrids is their simultaneous binding to catalytic and peripheral anionic site of AChE . However, one study also reported nonsignificant inhibition of AChE or change in kinetic parameters upon incubation with resveratrol . This study raises concerns about the poor bioavailability of resveratrol with reduced concentrations at targeted sites.…”

“…In silico study by Ali et al also suggested EGCG as AChE inhibitor. Recently, Salazar et al reported inhibition in human erythrocyte AChE at different concentrations (3‐200 μmol/L) of EGCG with IC 50 value of 18.5 μmol/L. In one in vitro study by Wang et al AChE inhibitory potential of different hydroxyl cinnamoylated catechins viz.…”

Characterization of phenolic profile by LC‐ESI‐MS/MS and enzyme inhibitory activities of two wild edible garlic: Allium nigrum L. and Allium subhirsutum L.

“…According to Katalinić et al, () galangin and kaempferol were the potent anticholinesterase compounds with greater anti‐BuChE activities. Also, Salazar, de Athayde Moncorvo Collado, Canal‐Martínez, & Minahk, ) and Jung and Park, () reported that EGCG and 3‐ O ‐methylquercetin had a potent anti‐AChE activity, respectively.…”