Screening of Korean herbal medicines used to improve cognitive function for anti-cholinesterase activity

Methanolic extracts of seven herbs ( Acorus calamus, Acorus gramineus, Bupleurm facaltum, Dioscorea batatas, Epimedium koreanum, Poria cocos and Zizyphi jujuba) used in traditional Korean medicine for improvement of memory and cognition in old age were tested for cholinesterase inhibitory properties using the Ellman colorimetric method. Significant inhibition of the enzyme at 200 μg/ml was observed for extracts from A. calamus and E. koreanum. The possible bases for the reputation of these and the other herbs tested are discussed in the light of previous investigations into their chemistry and biological activity.