Affiliations: [a] Institut de Neuropatologia, Servei d'Anatomia Patològica, IDIBELL-Hospital Universitari de Bellvitge, Universitat de Barcelona, L'Hospitalet de Llobregat, Spain | [b] CIBERNED, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas, Instituto Carlos III, Spain | [c] Departament d'Estadística, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain | [d] Statistics and Bioinformatics Unit, Institut de Recerca de l'Hospital Universitari de Vall d'Hebron, Barcelona, Spain | [e] Laboratori de Neurofarmacologia, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
Correspondence:
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Correspondence to: Ester Aso, Institut de Neuropatologia, Servei d'Anatomia Patològica, IDIBELL-Hospital Universitari de Bellvitge, C/Feixa Llarga s/n, 08907 L'Hospitalet de Llobregat, Spain. Tel.: +34 93 2607452; Fax: +34 93 2607503; E-mail: aso@bellvitgehospital.cat.
Abstract: Several recent findings suggest that targeting the endogenous cannabinoid system can be considered as a potential therapeutic approach to treat Alzheimer's disease (AD). The present study supports this hypothesis demonstrating that delta-9-tetrahydrocannabinol (THC) or cannabidiol (CBD) botanical extracts, as well as the combination of both natural cannabinoids, which are the components of an already approved cannabis-based medicine, preserved memory in AβPP/PS1 transgenic mice when chronically administered during the early symptomatic stage. Moreover, THC + CBD reduced learning impairment in AβPP/PS1 mice. A significant decrease in soluble Aβ42 peptide levels and a change in plaques composition were also observed in THC + CBD-treated AβPP/PS1 mice, suggesting a cannabinoid-induced reduction in the harmful effect of the most toxic form of the Aβ peptide. Among the mechanisms related with these positive cognitive effects, the anti-inflammatory properties of cannabinoids may also play a relevant role. Here we observed reduced astrogliosis, microgliosis, and inflammatory-related molecules in treated AβPP/PS1 mice, which were more marked after treatment with THC + CBD than with either THC or CBD. Moreover, other cannabinoid-induced effects were uncovered by a genome-wide gene expression study. Thus, we have identified the redox protein thioredoxin 2 and the signaling protein Wnt16 as significant substrates for the THC + CBD-induced effects in our AD model. In summary, the present findings show that the combination of THC and CBD exhibits a better therapeutic profile than each cannabis component alone and support the consideration of a cannabis-based medicine as potential therapy against AD.
