Background: Acetylcholinesterase and butyrylcholoinesterase inhibitors are well-known drugs commonly used in the treatment of Alzheimer’s disease (AD) to improve cognitive function. These enzyme inhibitors were reported to be found in many plants. Apai-sa-le recipe was a Thai tradition used as nootropic recipe and formerly claimed to improve memory. Therefore, it is interesting to investigate cholinesterase inhibitory activity of the recipe and its ingredients.
Objective: To determine the whole recipe of Apai-sa-le and its ingredients for inhibitory effect on acetylcholinesterase (AChE) and human butyrylcholinesterase (BuChE) activities.
Material and Method: Thirty grams of each plant and 181 grams of the whole recipe were separately extracted by 95% ethanol, after filtered the filtrate were evaporated and vacuum-dried at 45°C. By Elman method, the inhibitory activities of both enzymes were assessed. The volatile constituents of each extract were determined by GCMS. The constituents in the nonvolatile extract were examined by TLC and the antioxidant activity was determined.
Results: Four plants exhibited specific BuChE inhibitor were Lepidium sativum Linn. (Ls), Piper nigrum L. (Pn), Angelica
dahurica Benth (Ad) and Atractylodes lancea DC. (Al), which shown the IC50 of 5.59, 24.52, 73.23, 96.25 μg/ml, respectively whereas galantamine and the whole recipe showed IC50 of 0.59 and 236 μg/ml. Only Pn extract inhibited AChE at IC50 of 25.46 μg/ml. By GCMS and TLC fingerprints revealed the main constituents in LS, Ad, Al and Pn as apiol, cumialdehyde, furanodiene and piperine. Moreover, nine plant extracts and the whole recipe showed antioxidant activity.
Conclusion: Lepidium sativum Linn. (Ls) extract showed the most potency on BuChE inhibitory effect. Three ingredients and the whole recipe exhibited mild activity. Only Piper nigrum L demonstrated inhibition effect on both AChE and BuChE.

Keywords: Cholinesterase inhibitor, Apai-sa-le recipe