Abstract

This study tested the in vitro anti-acetylcholinesterase (AChE) and anti-butyrylcholinesterase (BChE) activities of simple phenolic acids using Ellman’s spectrophotometric method. 15 phenolic acids (at levels found in beer) exerted differentiated anticholinesterase activities, with the most efficient being chlorogenic, p-coumaric, p-hydroxybenzoic and caffeic acids. When present at levels similar to those detected in plasma after beer consumption (500 ml), vanillic, caffeic, syringic and p-coumaric acids exhibited anti-BChE activity. Phenolic acids were not interactive in a complex solution at concentrations found in plasma after beer consumption. Combined phenolic acids (p-hydroxyphenylacetic, ferulic, vanillic, caffeic, syringic, sinapic and p-coumaric, at 0.01 mM) showed both anticholinesterase activity and synergy between the individual compounds. Also, synergy was found in the case of selected pairs of phenolic acids (each at 0.01 mM), calculated using the method of expected inhibition and the interactive index of combination. These results support the idea that simple phenolic acids from beer can play a role in neuroprotection, but further studies need to be conducted.

Key words: Acetylcholinesterase, Alzheimer’s disease, beer, butyrylcholinesterase, phenolic acids.

Abbreviation

ACh, Acetylcholine; AChE, acetylcholinesterase; BChE,butyrylcholinesterase; ChAT, choline acetyltransferase; VA, vanillic acid; FA, ferulic acid; FAEE, ferulic acid ethyl ester; m-OH-BA, m-OH-benzoic acid; p-OH-BA, p-OH-benzoic acid; p-OH-PA, p-OH-phenylacetic acid; CA, caffeic acid; SA, sinapic acid;PCA, protocatechuic acid; CNA, cinnamic acid; p-CA, p-coumaric acid; o-CA, o-coumaric acid; SRA, syringic acid; GA, gallic acid; CHA, chlorogenic acid; HVA,homovanillic acid; ATChI, acetylthiocholine iodide; BTCh, S-butyrylthiocholine chloride; DTNB, 5,5’-dithiobis-2-nitrobenzoic acid; AD, Alzheimer’s disease.