Acetylcholinesterase inhibition by medicinal plants: A Review

Abstract

Acetylcholinesterase (AChE), the predominant cholinesterase in the brain, hydrolyzes ACh to choline and acetate, thereby terminating the effect of this neurotransmitter at cholinergic synapses. Therefore, AChE is the target of cholinesterase inhibitors used for addressing the cholinergic deficit in Alzheimer's disease (AD) patients. Despite decades of research and advances in our understanding of its aetiology and pathogenesis, current pharmacotherapeutic options for AD are still very limited and represent an area of need that is currently unmet. The leading AD therapeutics involves AChE inhibitors, resulting in increased acetylcholine concentrations in the synaptic cleft and enhanced cholinergic transmission. Compounds showing an AChE inhibitory effect are also used for the treatment of senile dementia, myastenia gravis, Parkinson's disease and ataxia. Taking into account that the inhibition of AChE has been one of the most used strategies for treating AD and that existing drugs are effective only against mild to moderate type of disease while presenting considerable side effects, the search for new sources of effective and selective anti acetylcholinesterase agents with fewer side effects is imperative. Various plants and phytochemical substances have demonstrated AChE inhibitory activity and thus could be beneficial in the treatment of neurodegenerative disorders such as AD.

Antioxidant and Anticholinesterase Activities of Macrosphyra Longistyla (DC) Hiern Relevant in the Management of Alzheimer’s Disease

“…The inhibition of cholinesterase enzymes is considered promising in the management of neurological and neurodegenerative disorders such as AD, senile dementia, ataxia, and myasthenia gravis, where a deficit in cholinergic neurotransmission is often observed [43,44]. Compounds with a dual inhibitory effect on AChE and BuChE are also considered better, as BuChE also plays a minor role in the regulation of AChE [45,46].…”

Neuroprotective Effect of Spice Oleoresins on Memory and Cognitive Impairment Associated with Scopolamine-Induced Alzheimer’s Disease in Rats

“…AChE hydrolyzes ACh to choline and acetate and terminates its effect at cholinergic synapses. 33 AChE activity was measured to explore the effect of spice oleoresins on the cholinergic function, which governs vital aspects of memory and other cognitive functions. In this study, scopolamine elevates AChE activity, an enzyme responsible for the deterioration of Ach.…”

Major Bioactive Alkaloids and Biological Activities of Tabernaemontana Species (Apocynaceae)

“…Currently, approved AChE inhibitors include tacrine, donepezil, rivastigmine, and galanthamine [ 238 , 241 , 242 ]. However, despite the beneficial effects on cognitive functioning, these inhibitors have displayed undesirable side effects, such as gastrointestinal issues, nausea, vomiting, and reduced bioavailability [ 243 , 244 ]. Considering the latter, the discovery of alternative natural AChE inhibitors displaying minimal side effects is essential [ 238 , 239 , 244 ].…”

“…However, despite the beneficial effects on cognitive functioning, these inhibitors have displayed undesirable side effects, such as gastrointestinal issues, nausea, vomiting, and reduced bioavailability [ 243 , 244 ]. Considering the latter, the discovery of alternative natural AChE inhibitors displaying minimal side effects is essential [ 238 , 239 , 244 ]. Therapeutic plants have been investigated for their complex compounds that contain natural and innovative AChE inhibitors [ 241 , 242 ].…”