BCHE and Alzheimer disease: The commonly used drugs for AD like memantine, is a N-methyl-D-aspartic acid (NMDA) receptor antagonist, which may restore the functions of damaged neurons through reducing abnormal excitatory signals via the modulation of NMDA receptor activity [36] and cholinesterase (AChE) inhibitors suppress the enzymatic hydrolysis of neurotransmitter acetylcholine, thus maintain a higher acetylcholine concentration in the neuronal synapse [37], provide a symptomatic relief but no cure for the disease.