ACHE and Alzheimer disease: Two major enzymes, acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), hydrolyze ACh and, up to now, pharmacological approaches for the treatment of AD mainly aim to restore acetylcholine (ACh) level in the brain through the administration of specific inhibitors (AChEI and BuChI) [7,8,9,10,11,12].