BCHE and dementia: Donepezil, a reversible inhibitor of cholinesterase which is clinically used for treatment of dementia, showed slightly weak (RI at p < 0.0593) cognition enhancing properties at 3 mg/kg i.p. The effect of 3 mg/kg donepezil is similar to 60 mg/kg i.p. of O. stamineus extract based on the mean at C1 and having changes to RI after treatment at p < 0.0593 and p < 0.0539, respectively.