Inhibition of Ptychopetalum olacoides on Acetylcholinesterase Isoforms in Brain of Mice

ObjectiveTo further characterize the acetylcholinesterase inhibitors (AChE-Is) pattern of Ptychopetalum olacoides ethanol extract (POEE) on the cytosolic globular monomer (G1) and membrane bound globular tetramer (G4) AChE isoforms in brain areas relevant for cognition.MethodsThe G1 and G4 AChE isoforms were prepared according to the reported methods and the determination of AChE activity used was adapted from colorimetric method.ResultsPOEE mostly inhibited G1 in hippocampus (75%), and G4 in frontal cortex (58%) and striatum (75%) (P < 0.05). Kinetic analysis indicated that POEE-induced AChE inhibition in hippocampus was of a competitive nature for G1 but uncompetitive for G4.ConclusionConsidering the high density of cholinergic projection to the cortex and striatum, and the usefulness of conserving cytosolic acetylcholine to replenish synaptic vesicles in a highly active cognition site such as hippocampus, we argue that this could be a desirable profile for a clinically relevant AChE-I.