Acetylcholinesterase Inhibitory Activity of Standardized Cannabinoids-rich Fractions

Background: Since cannabis has been legally allowed for medicinal purposes in many countries, it has become the most interesting issue, particularly in neurologic disorders, such as Alzheimer’s disease (AD). Inhibition of acetylcholinesterase (AChE) is one of the mechanisms for the treatment of AD. Objectives: The present study aimed to establish a method for the preparation of cannabinoid-rich extracts and determine their AChE inhibitory activity. Methods: The cannabinoid-rich extracts were prepared through a green extraction process using microwave-assisted extraction (MAE) followed by hydrophobic column separation. The contents of cannabidiol (CBD) and Δ-9-tetrahydrocannabinol (THC) were determined using high-performance liquid chromatography (HPLC). In vitro AChE inhibitory activity was determined via the photometric method using AChE from Electrophorus electricus. Results: Three cannabinoids-rich fractions were obtained with different concentrations of CBD and THC, namely Fractions I (CBD of 8.1% w/w; THC of 52.2% w/w), II (CBD of 9.2% w/w; THC of 8.0% w/w), and III (CBD 1.3% w/w, THC 33.5% w/w). These cannabinoid-rich extracts exhibited AChE inhibitory activity, with IC50 values of 52.3, 59.8, and 71.2 µg/mL, respectively. Conclusion: This finding suggests that CBD, but not THC, might be an active compound contributing to AChE inhibitory effect.