Dual-cholinesterase inhibition by an aqueous extract of Emblica officinalis fruit and its mode of inhibition by kinetic study

Emblica officinalis (Family: Euphorbiaceae) commonly known as Indian Gooseberry or Amla, is widely used in Ayurveda for its memory enhancing, anti-aging, anti-stress and antioxidant properties. This study evaluated the anti-cholinesterase activity of an aqueous extract from the fruits of Emblica officinalis as these are the key enzymes involved in cholinergic transmission. Cholinesterase inhibitors are the class of compounds which inhibit cholinesterase enzyme and are used as drugs for symptomatic treatment of Alzheimer’s disease (AD). The assessment of cholinesterase inhibition was carried out using a colorimetric method based on Ellman’s reaction. An aqueous extracts of Emblica officinalis fruit showed concentration dependent acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibition with maximum inhibition of 71.96±0.005% and 61.22±0.001% at 100μg/ml final concentrations with IC50 values of 26.84μg/mL and 33.11μg/mL respectively. The kinetic study using Lineweaver-Burk plots of an aqueous extract of Emblica officinalis fruit showed mixed mode of inhibition against both AChE and BuChE. This dual anti AChE and BuChE enzymes activity exhibited by an aqueous extracts of Emblica officinalis fruit showed potential in therapeutic application that might be beneficial in improving memory and other cognitive functions associated with the cholinergic system and might be used in future for symptomatic treatment of AD.