Cannabidiol Impairs Brain Mitochondrial Metabolism and Neuronal Integrity

Abstract

Background: The mechanisms underlying the clinical effects of CBD remain poorly understood. Given the increasing evidence for CBD's effects on mitochondria, we sought to examine in more detail whether CBD impacts mitochondrial function and neuronal integrity. Methods: We utilized BE(2)-M17 neuroblastoma cells or acutely isolated brain mitochondria from rodents using a Seahorse extracellular flux analyzer and a fluorescent spectrofluorophotometer assay. Mitochondrial ion channel activity and hippocampal long-term potentiation were measured using standard cellular electrophysiological methods. Spatial learning/memory function was evaluated using the Morris water maze task. Plasma concentrations of CBD were assessed with liquid chromatography–mass spectrometry, and cellular viability was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction neuronal injury assay. Results: At low micromolar concentrations, CBD reduced mitochondrial respiration, the threshold for mitochondrial permeability transition, and calcium uptake, blocked a novel mitochondrial chloride channel, and reduced the viability of hippocampal cells. These effects were paralleled by in vitro and in vivo learning/memory deficits. We further found that these effects were independent of cannabinoid receptor 1 and mitochondrial G-protein-coupled receptor 55. Conclusion: Our results provide evidence for concentration- and dose-dependent toxicological effects of CBD, findings that may bear potential relevance to clinical populations.

Therapeutic Polymer-Based Cannabidiol Formulation: Tackling Neuroinflammation Associated with Ischemic Events in the Brain

“…Notably, at the lower NPCBD dose (0.01 mg/mL, corresponding to 0.20 μM of CBD), OCR values affected by the OGD insult were restored, closely resembling those of the untreated (HEALTHY) cells. These findings align with previous studies using CBD at similar doses in cell lines such as hippocampal neurons (HT22 cells) and BE(2)-M17 neuroblastoma cells …”

“…Similar results have been reported in other studies employing monocultures and cocultures . Overall, results from Seahorse analysis indicate a neuroprotective effect provided by NPCBD, reducing OGD-induced oxidative stress, in line with previous findings. , …”

“…Furthermore, our data suggest a dose-dependent effect of NPCBD on HMC3, with the higher dose not ameliorating OGD-induced mitochondrial dysfunction. This aligns with previous findings demonstrating the dose-dependent nature of CBD’s effects . ECAR, an indicator of glycolysis, was also impaired after the OGD insult, showing some recovery after NPCBD treatment at 0.01 mg/mL, although the differences were not statistically significant (Figure B).…”

“…These findings align with previous studies using CBD at similar doses in cell lines such as hippocampal neurons (HT22 cells) 33 and BE(2)-M17 neuroblastoma cells. 39 Furthermore, our data suggest a dose-dependent effect of NPCBD on HMC3, with the higher dose not ameliorating OGD-induced mitochondrial dysfunction. This aligns with previous findings demonstrating the dose-dependent nature of CBD's effects.…”

Screening System of Cannabis sativa Extracts Based on Their Mitochondrial Safety Profile Using Cytochrome c Oxidase Activity as a Biomarker

“…Direct actions of cannabinoids on respiratory complexes have been described [ 35 ] independently of their action on mitochondrial cannabinoid receptors [ 22 ]. In particular, several studies have reported specific actions of THC and CBD on mitochondrial respiratory chain activity, ROS production and cellular integrity, promoting toxicological effects in certain cells that may be potentially relevant for clinical populations [ 36 ]. Furthermore, an increasing number of experimental evidences link cannabinoid modulation of mitochondrial metabolism to specific physiological processes, such as cognition and memory [ 19 ], underlining the need for accurate characterization of extracts to obtain the strains of greatest therapeutic interest.…”