Natural Product Inhibitors of Acetylcholinesterase

Abstract

Various natural products, such as physostigmine, have long been recognized as inhibitors of the enzyme acetylcholinesterase. Since the recent approval of galanthamine for the treatment of Alzheimer's disease by the blockage of acetylcholine degradation, attempts to find other inhibitors of the enzyme have multiplied, leading to promising candidates such as huperzine A. In this review, a listing is presented of natural product inhibitors, both alkaloid and nonalkaloid in origin. These have been isolated from plant, animal and microbial sources. Details of current testing methods on cholinesterases are given, including solution assays and screening techniques by TLC and HPLC.

Modulation of some markers of erectile dysfunction and malonaldehyde levels in isolated rat penile tissue with unripe and ripe plantain peels: identification of the constituents of the plants using HPLC

“…The inhibition of AChE by the extracts substantiate the folkloric use of plantain peels in the management and/or treatment of ED. The inhibition of AChE by the peels correlates with recent studies that plant derived AChE inhibitors can be employed in ameliorating ED, and can also prevent oxidative stress in neuronal cells of penile tissue (Ramassamy 2006;Hostettmann et al 2006;Butterfield and Lauderback 2002;Andersson 2011;Nunes and Webb 2012;Akomolafe et al 2016). The inhibition of AChE by the extracts could be associated with the presence of phenolic compounds.…”

Screening for acetylcholinesterase inhibitory activity in cyanobacteria of the genus Nostoc

“…200 mg of the freeze-dried biomass was homogenized with sea sand and extracted with 6 mL of methanolwater mixture (7:3, V/V) for 1 h. This mixture was then centrifuged, evaporated to dryness and redissolved in the same solvent to obtain concentration of 3 mg mL 21 for the AChE inhibitory test.…”

“…125 mL of 0.1 M phosphate buffer pH 8.0, 50 mL of 0.4 U mL 21 AChE, 25 mL of 7.6 mM DTNB and 20 mL of crude extract were used in the reaction mixture. For the blank, 50 mL of 0.4 U mL 21 AChE was replaced by the same volume of 0.1 M phosphate buffer pH 8.0. After 30 min incubation at 308C the reaction was started by the addition of 30 mL of 6.2 mM ATCI.…”

“…The system consisted of an Agilent 1100 Series LC/MSD Trap, ChemStation for LC 3D and LC/MSD Trap software (V4.1). 20 mL aliquots of the sample were injected onto a ZORBAX Eclipse XDB-C 8 column (150 £ 4.6 mm, 5 mm) and eluted with the mixture of methanol:water:formic acid (30:70:0.1, V/V/V) at a flowrate of 0.6 mL min 21 and methanol gradient of 30 -85% (0 -26.5 min), 85 -100% (26.5 -27.5 min), 100% (27.5 -37.0 min). UV detection (280 nm) was used with parameters of ESI-MS, positive ion polarity; dry temp., 3258C; nebulizer, 50 psi (345 kPa); dry gas, 10 L min 21 and capillary current, 59.8 nA.…”

Analysis of Amaryllidaceae alkaloids from Zephyranthes grandiflora by GC/MS and their cholinesterase activity

“…Currently, cholinesterase inhibition is the most used therapeutic treatment for the symptoms of AD (Lleó, 2007;Recanatini & Valenti, 2004). In recent years some overviews of natural product inhibitors of AChE were reported (Barbosa-Filho et al, 2006;Hostettmann et al, 2006).…”