The spread of SARS-CoV-2 and ongoing COVID-19 pandemic underscores the need for new treatments. Here we report that cannabidiol (CBD) inhibits infection of SARS-CoV-2 in cells and mice. CBD and its metabolite 7-OH-CBD, but not THC or other congeneric cannabinoids tested, potently block SARS-CoV-2 replication in lung epithelial cells. CBD acts after viral entry, inhibiting viral gene expression and reversing many effects of SARS-CoV-2 on host gene transcription. CBD inhibits SARS-CoV-2 replication in part by up-regulating the host IRE1 RNase endoplasmic reticulum (ER) stress response and interferon signaling pathways. In matched groups of human patients from the National COVID Cohort Collaborative, CBD (100 mg/ml...

Microglial activation is an invariant feature of Alzheimer's disease (AD). It is noteworthy that cannabinoids are neuroprotective by preventing β-amyloid (Aβ)-induced microglial activation both in vitro and in vivo. On the other hand, the phytocannabinoid cannabidiol (CBD) has shown anti-inflammatory properties in different paradigms. In the present study, we compared the effects of CBD with those of other cannabinoids on microglial cell functions in vitro and on learning behavior and cytokine expression after Aβ intraventricular administration to mice. CBD, (R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl) pyrrolo-[1,2,3-d,e]-1,4-benzoxazin-6-yl]-1-naphthalenyl-methanone [WIN 55,212-2 (WIN)], a mixed CB(1)/CB(2) agonist, and 1,1-dimethylbutyl-1-deoxy-Δ(9)-tetrahydrocannabinol [JWH-133 (JWH)], a CB(2)-selective agonist, concentration-dependently decreased ATP-induced (400 μM) increase in intracellular calcium...

Abstract Muscle disuse has numerous physiological consequences that end up with significant catabolic metabolism and ultimately tissue atrophy. What is not known is how muscle atrophy affects the endocannabinoid (EC) system. Arachidonic acid (AA) is the substrate for anandamide (AEA) and 2-arachidonylgycerol (2-AG), which act as agonists for cannabinoid receptors CB1 and CB2 found in muscle. Diets with n-3 polyunsaturated fatty acids (PUFA) have been shown to reduce tissue levels of AA, AEA and 2-AG. Therefore, we hypothesized that hind limb suspension (HS)-induced muscle atrophy and intake of n-3 PUFA will change mRNA levels of the EC system. Mice were randomized and assigned to...

Lidocaine is clinically widely used as a local anesthetic inhibiting propagation of action potentials in peripheral nerve fibers. Correspondingly, the functional magnetic resonance imaging (fMRI) response in mouse brain to peripheral noxious input is largely suppressed by local lidocaine administered at doses used in a clinical setting. We observed, however, that local administration of lidocaine at doses 100 lower than that used clinically led to a significantly increased sensitivity of mice to noxious forepaw stimulation as revealed by fMRI. This hyperalgesic response could be confirmed by behavioral readouts using the von Frey filament test. The increased sensitivity was found to involve a type 1...

Hypothalamic pro-opiomelanocortin (POMC) neurons promote satiety. Cannabinoid receptor 1 (CB1R) is critical for the central regulation of food intake. Here we test whether CB1R-controlled feeding in sated mice is paralleled by decreased activity of POMC neurons. We show that chemical promotion of CB1R activity increases feeding, and notably, CB1R activation also promotes neuronal activity of POMC cells. This paradoxical increase in POMC activity was crucial for CB1R-induced feeding, because designer-receptors-exclusively-activated-by-designer-drugs (DREADD)-mediated inhibition of POMC neurons diminishes, whereas DREADD-mediated activation of POMC neurons enhances CB1R-driven feeding. The Pomc gene encodes both the anorexigenic peptide α-melanocyte-stimulating hormone, and the opioid peptide β-endorphin. CB1R activation selectively increases...

Recent studies have shown that the endocannabinoid system is involved in the common neurobiological mechanism underlying drug addiction. This system participates in the primary rewarding effects of cannabinoids, nicotine, alcohol and opioids, through the release of endocannabinoids in the ventral tegmental area. Endocannabinoids are also involved in the motivation to seek drugs by a dopamine-independent mechanism, demonstrated for psychostimulants and opioids. The endocannabinoid system also participates in the common mechanisms underlying relapse to drugseeking behaviour by mediating the motivational effects of drug-related environmental stimuli and drug reexposure. In agreement, clinical trials have suggested that the CB1 cannabinoid antagonist rimonabant can cause smoking cessation. Thus,...

BACKGROUND: Cannabinoid type-1 (CB1) receptor inverse agonists improve type 2 diabetes and dyslipidaemia but were discontinued due to adverse psychiatric effects. D9 -Tetrahydrocannabivarin (THCV) is a neutral CB1 antagonist producing hypophagia and body weight reduction in lean mice. We investigated its effects in dietary-induced (DIO) and genetically (ob/ob) obese mice. METHODS: We performed two dose-ranging studies in DIO mice; study 1: 0.3, 1, 2.5, 5 and 12.5 mg kg 1 , oral twice daily for 30 days and study 2: 0.1, 0.5, 2.5 and 12.5 mg kg 1 , oral, once daily for 45 days. One pilot (study 3: 0.3 and 3 mg kg...

Fragile X syndrome, the most commonly known genetic cause of autism, is due to loss of the fragile X mental retardation protein, which regulates signal transduction at metabotropic glutamate receptor-5 in the brain. Fragile X mental retardation protein deletion in mice enhances metabotropic glutamate receptor-5-dependent long-term depression in the hippocampus and cerebellum. Here we show that a distinct type of metabotropic glutamate receptor-5-dependent long-term depression at excitatory synapses of the ventral striatum and prefrontal cortex, which is mediated by the endocannabinoid 2-arachidonoyl-sn-glycerol, is absent in fragile X mental retardation protein-null mice. In these mutants, the macromolecular complex that links metabotropic glutamate receptor-5 to the...