The inhibition effect of oleamide for acetylcholinesterase and α-glucosidase from edible wild mushroom by in vitro, in silico and fluorescence analysis.

Lipid compounds from edible wild mushrooms have been reported for their biological activities related to Alzheimer's disease (AD) and diabetes mellitus (DM) treatment. This research investigated purified oleamide (PEWM) from edible wide mushroom and determined its antioxidant activity and inhibition potential against acetylcholinesterase (AChE) and α-glucosidase. The PEWM was purified by preparative thin-layer chromatography (PTLC) with methanol: chloroform: water (6:6:1 v/v). The antioxidant activity against ABTS and DPPH· radical of crude extracts (CEWM) had higher potent than PEWM. On the other hand, the inhibition potential of PEWM against AChE and α-glucosidase had higher potency than CEWM. Moreover, the inhibition potency of PEWM and oleamide against AChE was higher than α-glucosidase. The inhibition mode of CEWM, PEWM and oleamide exhibited mixed-type inhibition on AChE and α-glucosidase. Inhibition constant (K) also supported that CEWM, PEWM and oleamide have the highest potent on AChE. CEWM, PEWM and oleamide showed fluorescence quenching by increasing the inhibitors' concentration against AChE and α-glucosidase. Docking analysis revealed that oleamide was located in peripheral anionic sites of AChE. The results suggest that edible wild mushrooms as the source of lipids related to AChE and α-glucosidase inhibitory activity might be applied for AD and DM management.