Moreover, the effects of these drugs on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities in the cholinergic system associated with Alzheimer's disease, which is one of the neurodegenerative diseases, and on Paraoxonase 1 (PON1) activity and total thiol level, which play a role in the cellular antioxidant defence system, were determined. This evidence concerns the gene PON1 and neurodegenerative disease.