Introduction: Alzheimer’s disease, a type of progressive dementia, is a neurodegenerative disorder characterized by a gradual cognitive decline resulting from selective neuronal dysfunction, synaptic loss, and neuronal cell death. Reduction in the level of the acetylcholine (ACh) neurotransmitter has been observed in the brains of AD patients, and inhibition of acetylcholinesterase (AChE), the critical enzyme which hydrolyzes ACh, is a significant treatment for AD. Medicinal plants consist of several pharmacologically active compounds and are an excellent source for finding new compounds with AChE inhibitory activity. In the present study, the AChE inhibitory activity of eight Nepeta species
from Iran was tested. Method: Nepeta species
were collected and dried, and then methanolic extracts of plants were prepared by the sonication method. These extracts were tested for their in vitro antiacetylcholinesterase activity based on Ellman’s colorimetric assay. Results: Among studied Nepeta species, N. denudata, N. assurgens and N. cephaloides had more inhibitory effects with IC50 value about 200 μg/ml. Conclusion: This study suggests that the methanolic extracts of N. denudata, N. assurgens and N. cephaloides can be considered as a promising therapeutic agent for the treatment of AD and alsoas a new source for finding new compound with AChE inhibitory effect.