The polyherbal test formulation along with a placebo was given to healthy elderly subjects while the SDAT patients received either the test formulation containing extracts of Bacopa monnieri ( whole plant ) , Hippophae rhamnoides ( leaves and fruits ) and Dioscorea bulbifera ( bulbils ) at a dose of @ mg or donepezil drug ( Aricept ) at a dose of @ mg , twice daily , for a period of @ months .