Hemp Bark Extract Improves Memory and Targets Alzheimer’s-Related Pathways, Study Finds
- Hemp bark extract improved memory and learning in mice with chemically induced cognitive dysfunction, targeting biological pathways related to Alzheimer’s disease.
- The extract inhibited key enzymes (AChE, BuChE, MAO-B) involved in neurotransmitter regulation and reduced oxidative stress in neuronal cells.
- In behavioral tests, oral administration of hemp bark extract significantly enhanced cognitive performance in scopolamine-impaired mice, with no major difference between 100 mg/kg and 200 mg/kg doses.
- Multiple cannabinoids in the extract (CBD, CBDA, CBCA) acted synergistically to inhibit enzymes, supported by molecular docking and dynamics simulations, suggesting multi-target therapeutic potential for cognitive dysfunction.
Hemp bark extract improved memory and learning in mice with chemically induced cognitive dysfunction while also targeting several biological pathways associated with Alzheimer’s disease, according to a new study.
The research was conducted by scientists affiliated with Hallym University and Kangwon National University in South Korea. Researchers examined extracts made from hemp root, stem, bark, leaf and seed, finding that the bark extract produced one of the strongest overall combinations of enzyme-inhibiting and antioxidant effects.
Among the extracts tested, hemp bark extract inhibited acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) and monoamine oxidase-B (MAO-B), enzymes associated with neurotransmitter regulation and cognitive dysfunction. The extract also reduced the formation of reactive oxygen species and restored activity of the antioxidant enzyme superoxide dismutase in neuronal cells.
Researchers then tested the extract in male mice given scopolamine, a drug commonly used to temporarily disrupt cholinergic signaling and produce memory and learning deficits. Thirty mice were divided into six groups of five, with animals receiving either no treatment, scopolamine, a vehicle solution, the Alzheimer’s medication donepezil or hemp bark extract at doses of 100 or 200 milligrams per kilogram.
The hemp bark extract was administered orally once per day for 28 days. Cognitive performance was measured using passive avoidance and Morris water maze tests.
Both doses of hemp bark extract significantly improved performance compared with mice experiencing scopolamine-induced impairment. In the water maze, treatment significantly reduced the time needed to find the hidden platform, indicating improved spatial learning and memory. Researchers found no significant difference between the two doses, suggesting the lower 100 mg/kg dose may have been near the maximum effective dose in this model.
Chemical analysis identified 26 compounds in the bark extract, including seven cannabinoids selected for additional testing: cannabidiol (CBD), cannabidiolic acid (CBDA), cannabichromene (CBC), cannabichromenic acid (CBCA), cannabidivarin (CBDV), delta-9 THC and delta-9 tetrahydrocannabivarin (THCV).
The cannabinoids displayed different activity across the three enzymes. CBC was the strongest inhibitor of AChE, while CBCA showed the strongest BuChE inhibition. CBD was the most potent MAO-B inhibitor, followed by CBDA. Researchers concluded that CBD, CBDA and CBCA had the most relevant overall multi-target profiles, suggesting the effects of the bark extract may result from multiple cannabinoids acting together rather than one compound alone.
The study also used molecular docking and 100-nanosecond molecular dynamics simulations to examine how the cannabinoids interacted with the enzymes, with the computational findings generally supporting the laboratory results.
The researchers concluded that hemp bark extract displayed “significant multi-target activity” relevant to Alzheimer’s-related cognitive dysfunction, combining cholinesterase and MAO-B inhibition with antioxidant effects and protection against experimentally induced memory impairment.