To be ionized or not to be ionized: the vital role of physicochemical properties of galbanic acid derivatives in AChE assay

Acetylcholinesterase inhibitory activity of Ferula plants and their potential for treatment of Alzheimer's disease

One of the current strategies in the treatment of Alzheimer's disease is using drugs with acetylcholinesterase (AChE) inhibitory property. The existence of various compounds in plants as a potential source for finding new compounds to treat Alzheimer's disease is a scientific fact. Many secondary metabolites and plant extracts have been reported with the ability to inhibit the AChE activity and improve memory and learning. These compounds can increase the concentration of acetylcholine in the brain and improve cholinergic function in individuals with Alzheimer's disease and reduce the symptoms of this neurological disorder. Plants of Ferula genus are a good source of biologically active compounds such as sesquiterpene derivatives, coumarin derivatives and sulfur-containing compounds. Numerous studies on various extracts or purified compounds of Ferula genus have shown that members of this genus have the inhibitory properties on acetylcholinesterase and can also be effective in improving Alzheimer's and amnesia. This review article summarizes studies on plants of Ferula extracts and their derived compounds to find AChE inhibitors.

An arginine-rich peptide inhibits AChE: template-based design, molecular modeling, synthesis, and biological evaluation

Life expectancy is growing especially in developed countries. In this regard, aging-associated diseases such as Alzheimer's disease (AD) are more common. Multi interconnected pathological factors involved in AD demand multi-target therapeutics. AChE, as a well-known target in AD, decreases the acetylcholine (ACh) in cholinergic synapse and, besides, increases the rate of amyloid-beta (Aβ) aggregation. To block the destructive effects of AChE on cholinergic neurons in AD, we designed a peptidic inhibitor of the peripheral anionic site (PAS). The PAS plays a crucial role to attract and direct the ACh to the enzyme active site and increase the rate of Aβ aggregation by changing the folding state. We utilized the template-based approach in combination with molecular docking, molecular dynamic simulation, and data mining to design a peptide library. Scoring was performed according to binding energy and the interaction profile of AChE inhibitors. The best candidate (p8, RMLRTTRY) was synthesized using solid-phase peptide synthesis, purified by RP-HPLC, and identified by ESI-MS. The inhibitory effect of p8 on AChE was 102.2 ± 15.2 μM. The kinetic and molecular modeling studies indicated the mixed inhibition mechanism for p8. The Arg residues in p8 had an essential role in binding to PAS.