In vitro evaluation of acetyl and butyrylcholinesterase inhibitory activity of apricot (Prunus armeniaca L.) kernel extracts

Abstract

Introduction Cholinergic system plays a major role in the process of recognition, and Cholinesterase enzymes are important enzymes of this system. One of the main pathological mechanisms of the cognitive impairment associated with neurodegenerative diseases is cholinergic system dysfunction and recently, cholinesterase inhibitors are one of the most commonly used treatments for cognitive impairment associated with neurodegenerative diseases. Prunus armeniaca (common name: apricot) is a tree of the Rosacea family, which its fruit and kernels has demonstrated many biological properties in various studies. Objective This study was designed to evaluate the possible inhibitory activity of different extracts of sweet and bitter apricot kernel and amygdalin as the main constituent of the plant on cholinesterase enzymes. Methods The sweet and bitter apricot kernel was collected from the Ivand village in 39.4 km from Tabriz on July 2016 and herbarium specimen was recorded. After milling the sample and removing the oil with petroleum ether solvent, part of the sample using hot water, part of the sample with 70% methanol and part by ethanol were extracted. The probable inhibition of acetylcholinesterase (AChE) and butyrylcholine esterase (BChE) were measured by Ellman's test. The amount of phenolic and flavonoid compounds, neuroprotective effects, and the analysis of the compounds present in GC / MS in the most effective extract of sweet and bitter nucleoli were also investigated. Results In the AChE inhibitory test, the aqueous extract of the bitter apricot kernels had the highest activity with IC50 = 134.93μg / mL and none of the extracts did exhibit any noticeable inhibitory activity against BChE (IC50500). Furthermore,amygdalin showed no inhibitory activity on cholinesterase enzymes (IC50500). Also, aqueous extract of bitter apricot kernel indicated significant neuroprotective effect (cell viability = 81.47 % with P value < 0.0001) against H2O2-induced cell death in PC12 neurons. Conclusion According to the hypothesis of inhibiting cholinesterase in Alzheimer's disease, the bitter aqueous extract is the most effective extract in improving the symptoms of this disease, which is consistent with the traditional herbal preparation method. Likewise, the observed effects are probably due to the synergistic effects of the active compounds of the extract.