Identification of Cannabidiolic and Cannabigerolic Acids as MTDL AChE, BuChE, and BACE-1 Inhibitors Against Alzheimer's Disease by In Silico, In Vitro, and In Vivo Studies

Cannabidiolic (CBDA) and cannabigerolic (CBGA) acids are naturally occurring compounds from Cannabis sativa plant, previously identified by us as dual PPARα/γ agonists. Since the development of multitarget-directed ligands (MTDL) represents a valuable strategy to alleviate and slow down the progression of multifactorial diseases, we evaluated the potential ability of CBDA and CBGA to also inhibit enzymes involved in the modulation of the cholinergic tone and/or β-amyloid production. A multidisciplinary approach based on computational and biochemical studies was pursued on selected enzymes, followed by behavioral and electrophysiological experiments in an AD mouse model. The β-arrestin assay on GPR109A and qPCR on TRPM7 were also carried out. CBDA and CBGA are effective on both acetyl- and butyryl-cholinesterases (AChE/BuChE), as well as on β-secretase-1 (BACE-1) enzymes in a low micromolar range, and they also prevent aggregation of β-amyloid fibrils. Computational studies provided a rationale for the competitive (AChE) vs. noncompetitive (BuChE) inhibitory profile of the two ligands. The repeated treatment with CBDA and CBGA (10 mg/kg, i.p.) improved the cognitive deficit induced by the β-amyloid peptide. A recovery of the long-term potentiation in the hippocampus was observed, where the treatment with CBGA and CBDA also restored the physiological expression level of TRPM7, a receptor channel involved in neurodegenerative diseases. We also showed that these compounds do not stimulate GPR109A in β-arrestin assay. Collectively, these data broaden the pharmacological profile of CBDA and CBGA and suggest their potential use as novel anti-AD MTDLs.