Cannabinoid Treatment Reduced Alzheimer's Plaques and Improved Memory in Mice

Chronic treatment with JWH-133 (a selective CB2 agonist) and Cannabis sativa extract reduced anxiety-like behavior and partially reversed recognition memory deficits in APP/PS1 mice. Both treatments reduced the number and size of amyloid-beta plaque deposits, decreased cerebral glucose metabolism, reduced mTOR and CB2 receptor expression, and enhanced M1 muscarinic acetylcholine receptor expression.

APP/PS1 transgenic mice (Alzheimer's model) received 90 days of intermittent treatment with JWH-133 (0.2 mg/kg) or EU-GMP certified Cannabis sativa (Cannabixir Medium Flos, 2.5 mg/kg). Recognition memory, anxiety behavior, brain imaging, and molecular markers were assessed.

Alzheimer's disease has no effective treatment despite decades of research. The finding that cannabinoid receptor ligands can reduce plaque deposits and improve cognition in an Alzheimer's model, through the expanded endocannabinoid system, opens a new therapeutic avenue worth pursuing.

The endocannabinoid system is increasingly recognized as a modulator of neuroinflammation and neurodegeneration. That both a selective CB2 agonist and a full cannabis extract showed similar benefits suggests the CB2 receptor pathway may be a key therapeutic target for Alzheimer's.

Mouse model findings often do not translate to human Alzheimer's. APP/PS1 mice only model the amyloid component of Alzheimer's, not the full disease. The treatment regimen (90 days intermittent) may not represent practical clinical dosing. No long-term follow-up.