CHAT and Alzheimer disease: This neurotransmitter is terminated by an enzyme known as Acetylcholinesterase (AChE), and butyryl cholinesterase (BChE), which is present in patients with AD as well as inhibiting of choline acetyltransferase (ChAT) activity (an enzyme responsible for ACh metabolism) [243].Studies have shown that Rb1,Rb2, Rc,Re,Rg1 and Rg3 have a reducing property on AChE and BChE [243, 244].