Introduction: Alzheimer disease (AD) is the most widely recognised neurodegenerative disorder in the ageing population, characterised by progressive neuronal loss. The enhanced level of acetylcholine (ACh) in the human brain is another measure of identifying the progression of the disease. Increased acetylcholinesterase (AChE) level plays a fundamental role in the hydrolysis of Ach which worsens the cognitive function. Though there are several medications or drugs currently used in treating AD, their clinical implications remains debatable due to its adverse effects. Methods: In this study, the combined nutraceutical effect of natural plant compounds, piperine and curcumin were evaluated for acetylcholinesterase inhibitory assay using Ellman colourimetric method. Results: Results obtained from the study revealed that combined effects of natural plant compounds showed promising acetylcholinesterase inhibition activity with an IC50 of 104.1 ± 0.08 µg/mL compared to individually treated compounds, i.e., IC50 of curcumin = 134.5 ± 0.05 µg/mL and IC50 of piperine = 62.81 ± 0.00 µg/mL. Conclusion: The results suggest that the natural plant compounds taken in combination act as natural acetylcholinesterase inhibitors, and could be beneficial in the treatment of AD.