Raphael Mechoulam

E. Murillo-Rodríguez, G. Arankowsky-Sandoval, R.G. Pertwee, L. Parker, and R. Mechoulam. 2020. “Sleep and neurochemical modulation by cannabidiolic acid methyl ester in rats.” Brain Research Bulletin, 155, Pp. 166-173. Publisher's Version Abstract
Cannabidiolic acid methyl ester (HU-580) is a more stable compound than cannabidiolic acid (CBDA) which has been shown to be effective in reducing nausea, anxiety, depression behaviors in animal models. Here we extend the investigation of this compound to determine its effect on the sleep-wake cycle in male Wistar rats. HU-580 dose-dependently (0.1, 1.0 or 100 μg/Kg, i.p.) prolonged wakefulness (W) and decreased slow wave sleep (SWS) duration whereas rapid eye movement sleep (REMS) showed no statistical change. In addition, the brain microdialysis probes either placed at nucleus accumbens (NAc) or into the basal forebrain in freely moving animals were used to evaluate the effects of HU-580 treatment on neurotransmitters related to the sleep-wake cycle modulation. HU-580 enhanced extracellular levels of dopamine, serotonin collected from NAc while adenosine and acetylcholine were increased in basal forebrain. In summary, HU-580 seems to possess wake-promoting pharmacological properties and enhances the levels of wake-related neurochemicals. This is the first report of effects of HU-580 on sleep modulation expanding the very limited existent data on the neurobiological effects of HU-580 on rats. © 2019 Elsevier Inc.
E.M. Rock, S.M. Ayoub, C.L. Limebeer, A. Gene, K.L. Wills, M.V. DeVuono, R. Smoum, V. Di Marzo, A.H. Lichtman, R. Mechoulam, and L.A. Parker. 2020. “Acute naloxone-precipitated morphine withdrawal elicits nausea-like somatic behaviors in rats in a manner suppressed by N-oleoylglycine.” Psychopharmacology, 237, 2, Pp. 375-384. Publisher's Version Abstract
Rationale: Acute naloxone-precipitated morphine withdrawal (MWD) produces a conditioned place aversion (CPA) in rats even after one or two exposures to high-dose (20 mg/kg, sc) morphine followed 24-h later by naloxone (1 mg/kg, sc). However, the somatic withdrawal reactions produced by acute naloxone-precipitated MWD in rats have not been investigated. A recently discovered fatty acid amide, N-oleoylglycine (OlGly), which has been suggested to act as a fatty acid amide hydrolase (FAAH) inhibitor and as a peroxisome proliferator-activated receptor alpha (PPARα) agonist, was previously shown to interfere with a naloxone-precipitated MWD-induced CPA in rats. Objectives: The aims of these studies were to examine the somatic withdrawal responses produced by acute naloxone-precipitated MWD and determine whether OlGly can also interfere with these responses. Results: Here, we report that following two exposures to morphine (20 mg/kg, sc) each followed by naloxone (1 mg/kg, sc) 24 h later, rats display nausea-like somatic reactions of lying flattened on belly, abdominal contractions and diarrhea, and display increased mouthing movements and loss of body weight. OlGly (5 mg/kg, ip) interfered with naloxone-precipitated MWD-induced abdominal contractions, lying on belly, diarrhea and mouthing movements in male Sprague–Dawley rats, by both a cannabinoid 1 (CB1) and a PPARα mechanism of action. Since these withdrawal reactions are symptomatic of nausea, we evaluated the potential of OlGly to interfere with lithium chloride (LiCl)-induced and MWD-induced conditioned gaping in rats, a selective measure of nausea; the suppression of MWD-induced gaping reactions by OlGly was both CB1 and PPARα mediated. Conclusion: These results suggest that the aversive effects of acute naloxone-precipitated MWD reflect nausea, which is suppressed by OlGly. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.
S.M. Ayoub, R. Smoum, M. Farag, H. Atwal, S.A. Collins, E.M. Rock, C.L. Limebeer, F. Piscitelli, F.A. Iannotti, A.H. Lichtman, F. Leri, V. Di Marzo, R. Mechoulam, and L.A. Parker. 2020. “Oleoyl alanine (HU595): a stable monomethylated oleoyl glycine interferes with acute naloxone precipitated morphine withdrawal in male rats.” Psychopharmacology, 237, 9, Pp. 2753-2765. Publisher's Version Abstract
Rationale: Oleoyl glycine, a little studied fatty acid amide similar in structure to anandamide, interferes with nicotine addiction in mice and acute naloxone-precipitated morphine withdrawal (MWD) in rats. Because endogenous oleoyl glycine is subject to rapid enzymatic deactivation, we evaluated the potential of more stable analogs to interfere with opiate withdrawal. Objectives: The potential of monomethylated oleoyl glycine (oleoyl alanine, HU595) to interfere with somatic and aversive effects of acute naloxone-precipitated MWD, its duration, and mechanism of action was assessed in male Sprague Dawley rats. The potential of dimethylated oleoyl glycine (HU596) to interfere with the aversive effects of naloxone-precipitated MWD was also investigated. Results: Oleoyl alanine (HU595) interfered with somatic and aversive effects produced by naloxone-precipitated MWD at equivalent doses (1 and 5 mg/kg, i.p.) as we have reported for oleoyl glycine; however, oleoyl alanine produced a longer lasting (60 min) interference, yet did not produce rewarding or aversive effects on its own and did not modify locomotor activity. HU596 was not effective. The interference with aversive effects of naloxone-precipitated MWD by oleoyl alanine was prevented by both a PPARα antagonist and a CB1 receptor antagonist. Accordingly, the compound was found to inhibit FAAH and activate PPARα in vitro. Finally, oleoyl alanine also reduced acute naloxone-precipitated MWD anhedonia, as measured by decreased saccharin preference. Conclusions: Oleoyl alanine (also an endogenous fatty acid) may be a more stable and effective treatment for opiate withdrawal than oleoyl glycine. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.
F. Piscitelli, F. Guida, L. Luongo, F.A. Iannotti, S. Boccella, R. Verde, A. Lauritano, R. Imperatore, R. Smoum, L. Cristino, A.H. Lichtman, L.A. Parker, R. Mechoulam, S. Maione, and V. Di Marzo. 2020. “Protective Effects of N-Oleoylglycine in a Mouse Model of Mild Traumatic Brain Injury.” ACS Chemical Neuroscience, 11, 8, Pp. 1117-1128. Publisher's Version Abstract
Traumatic brain injury (TBI) is one of the main causes of death in young people for which currently no efficacious treatment exists. Recently, we have reported that mice with mild-TBI with a specific injury in the insula showed elevated levels of a little investigated N-acyl amino acid, N-oleoylglycine (OlGly). N-acyl amino acids have recently experienced an increased interest because of their important biological activities. They belong to the endocannabinoidome family of lipids with structural similarities with the endocannabinoids (eCBs). The aim of this study was to test the neuroprotective and antihyperalgesic actions of OlGly in a model of mouse mild-TBI (mTBI) and its effect on levels of eCBs and N-acylethanolamines at the end of treatment. Following mTBI, mice were administered a daily injection of OlGly (10-50-100 mg/kg i.p.) for 14 days. Treatment with OlGly normalized motor impairment and behavior in the light/dark box test, ameliorated TBI-induced thermal hyperalgesia and mechanical allodynia, and normalized aggressiveness and depression. Moreover, levels of eCBs and some N-acylethanolamines underwent significant changes 60 days after TBI, especially in the prefrontal cortex and hypothalamus, and OlGly reversed some of these changes. In conclusion, our findings reveal that OlGly ameliorates the behavioral alterations associated with mTBI in mice, while concomitantly modulating eCB and eCB-like mediator tone. © 2020 American Chemical Society.
E.M. Rock, M.T. Sullivan, S.A. Collins, H. Goodman, C.L. Limebeer, R. Mechoulam, and L.A. Parker. 2020. “Evaluation of repeated or acute treatment with cannabidiol (CBD), cannabidiolic acid (CBDA) or CBDA methyl ester (HU-580) on nausea and/or vomiting in rats and shrews.” Psychopharmacology, 237, 9, Pp. 2621-2631. Publisher's Version Abstract
Rationale: When acutely administered intraperitoneally, the non-psychoactive cannabinoid cannabidiol (CBD), its acidic precursor cannabidiolic acid (CBDA) and a stable methyl ester of CBDA (HU-580) reduce lithium chloride (LiCl)–induced conditioned gaping in male rats (a selective preclinical model of acute nausea) via activation of the serotonin 1A (5-HT1A) receptor. Objectives: To utilise these compounds to manage nausea in the clinic, we must determine if their effectiveness is maintained when injected subcutaneously (s.c) and when repeatedly administered. First, we compared the effectiveness of each of these compounds to reduce conditioned gaping following repeated (7-day) and acute (1-day) pretreatments and whether these anti-nausea effects were mediated by the 5-HT1A receptor. Next, we assessed whether the effectiveness of these compounds can be maintained when administered prior to each of 4 conditioning trials (once per week). We also evaluated the ability of repeated CBD (7 days) to reduce LiCl-induced vomiting in Suncus murinus. Finally, we examined whether acute CBD was equally effective in male and female rats. Results: Both acute and repeated (7 day) s.c. administrations of CBD (5 mg/kg), CBDA (1 μg/kg) and HU-580 (1 μg/kg) similarly reduced LiCl-induced conditioned gaping, and these effects were blocked by 5HT1A receptor antagonism. When administered over 4 weekly conditioning trials, the anti-nausea effectiveness of each of these compounds was also maintained. Repeated CBD (5 mg/kg, s.c.) maintained its anti-emetic efficacy in S. murinus. Acute CBD (5 and 20 mg/kg, s.c.) administration reduced LiCl-induced conditioned gaping similarly in male and female rats. Conclusion: When administered repeatedly (7 days), CBD, CBDA and HU-580 did not lose efficacy in reducing nausea and continued to act via agonism of the 5-HT1A receptor. When administered across 4 weekly conditioning trials, they maintained their effectiveness in reducing LiCl-induced nausea. Repeated CBD also reduced vomiting in shrews. Finally, CBD’s anti-nausea effects were similar in male and female rats. This suggests that these cannabinoids may be useful anti-nausea and anti-emetic treatments for chronic conditions, without the development of tolerance. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.
T. Stark, M. Di Bartolomeo, R. Di Marco, E. Drazanova, C.B.M. Platania, F.A. Iannotti, J. Ruda-Kucerova, C. D'Addario, L. Kratka, V. Pekarik, F. Piscitelli, Z. Babinska, J. Fedotova, G. Giurdanella, S. Salomone, A. Sulcova, C. Bucolo, C.T. Wotjak, Jr Starcuk, Z., F. Drago, R. Mechoulam, V. Di Marzo, and V. Micale. 2020. “Altered dopamine D3 receptor gene expression in MAM model of schizophrenia is reversed by peripubertal cannabidiol treatment.” Biochemical Pharmacology, 177. Publisher's Version Abstract
Gestational methylazoxymethanol acetate (MAM) treatment produces offspring with adult phenotype relevant to schizophrenia, including positive- and negative-like symptoms, cognitive deficits, dopaminergic dysfunction, structural and functional abnormalities. Here we show that adult rats prenatally treated with MAM at gestational day 17 display significant increase in dopamine D3 receptor (D3) mRNA expression in prefrontal cortex (PFC), hippocampus and nucleus accumbens, accompanied by increased expression of dopamine D2 receptor (D2) mRNA exclusively in the PFC. Furthermore, a significant change in the blood perfusion at the level of the circle of Willis and hippocampus, paralleled by the enlargement of lateral ventricles, was also detected by magnetic resonance imaging (MRI) techniques. Peripubertal treatment with the non-euphoric phytocannabinoid cannabidiol (30 mg/kg) from postnatal day (PND) 19 to PND 39 was able to reverse in MAM exposed rats: i) the up-regulation of the dopamine D3 receptor mRNA (only partially prevented by haloperidol 0.6 mg/kg/day); and ii) the regional blood flow changes in MAM exposed rats. Molecular modelling predicted that cannabidiol could bind preferentially to dopamine D3 receptor, where it may act as a partial agonist according to conformation of ionic-lock, which is highly conserved in GPCRs. In summary, our results demonstrate that the mRNA expression of both dopamine D2 and D3 receptors is altered in the MAM model; however only the transcript levels of D3 are affected by cannabidiol treatment, likely suggesting that this gene might not only contribute to the schizophrenia symptoms but also represent an unexplored target for the antipsychotic activity of cannabidiol. © 2020 Elsevier Inc.
P. Pacher, N.M. Kogan, and R. Mechoulam. 2020. “Beyond THC and endocannabinoids.” Annual Review of Pharmacology and Toxicology, 60, Pp. 637-659. Publisher's Version Abstract
Research in the cannabinoid field, namely on phytocannabinoids, the endogenous cannabinoids anandamide and 2-arachidonoyl glycerol and their metabolizing and synthetic enzymes, the cannabinoid receptors, and anandamide-like cannabinoid compounds, has expanded tremendously over the last few years. Numerous endocannabinoid-like compounds have been discovered. The Cannabis plant constituent cannabidiol (CBD) was found to exert beneficial effects in many preclinical disease models ranging from epilepsy, cardiovascular disease, inflammation, and autoimmunity to neurodegenerative and kidney diseases and cancer. CBD was recently approved in the United States for the treatment of rare forms of childhood epilepsy. This has triggered the development of many CBD-based products for human use, often with overstated claims regarding their therapeutic effects. In this article, the recently published research on the chemistry and biological effects of plant cannabinoids (specifically CBD), endocannabinoids, certain long-chain fatty acid amides, and the variety of relevant receptors is critically reviewed. Copyright © 2020 by Annual Reviews. All rights reserved.
Y.F. Zhu, K. Linher-Melville, M.J. Niazmand, M. Sharma, A. Shahid, K.L. Zhu, N. Parzei, J. Sidhu, C. Haj, R. Mechoulam, and G. Singh. 2020. “An evaluation of the anti-hyperalgesic effects of cannabidiolic acid-methyl ester in a preclinical model of peripheral neuropathic pain.” British Journal of Pharmacology, 177, 12, Pp. 2712-2725. Publisher's Version Abstract
Background and Purpose: Chronic neuropathic pain (NEP) is associated with growing therapeutic cannabis use. To promote quality of life without psychotropic effects, cannabinoids other than Δ9-tetrahydrocannabidiol, including cannabidiol and its precursor cannabidiolic acid (CBDA), are being evaluated. Due to its instability, CBDA has been understudied, particularly as an anti-nociceptive agent. Adding a methyl ester group (CBDA-ME) significantly enhances its stability, facilitating analyses of its analgesic effects in vivo. This study examines early treatment efficacy of CBDA-ME in a rat model of peripherally induced NEP and evaluates sex as a biological variable. Experimental Approach: After 14 consecutive days of intraperitoneal CBDA-ME administration at 0.01, 0.1 and 1 μg·kg−1, commencing 1 day after surgically implanting a sciatic nerve-constricting cuff to induce NEP, the anti-nociceptive efficacy of this cannabinoid was assessed in male and female Sprague–Dawley rats relative to vehicle-treated counterparts. In females, 2 and 4 μg·kg−1 daily doses of CBDA-ME were also evaluated. Behavioural tests were performed for hind paw mechanical and thermal withdrawal thresholds once a week for 8 weeks. At endpoint, in vivo electrophysiological recordings were obtained to characterize soma threshold changes in primary sensory neurons. Key Results: In males, CBDA-ME elicited a significant concentration-dependent chronic anti-hyperalgesic effect, also influencing both nociceptive and non-nociceptive mechanoreceptors, which were not observed in females at any of the concentrations tested. Conclusion and Implications: Initiating treatment of a peripheral nerve injury with CBDA-ME at an early stage post-surgery provides anti-nociception in males, warranting further investigation into potential sexual dimorphisms underlying this response. © 2020 The British Pharmacological Society
L. Shbiro, D. Hen-Shoval, N. Hazut, K. Rapps, S. Dar, G. Zalsman, R. Mechoulam, A. Weller, and G. Shoval. 2019. “Effects of cannabidiol in males and females in two different rat models of depression.” Physiology and Behavior, 201, Pp. 59-63. Publisher's Version Abstract
The current study explores the therapeutic potential of Cannabidiol (CBD), a compound in the Cannabis plant, using both sexes of 2 “depressive-like” genetic models, Wistar Kyoto (WKY) and Flinders Sensitive Line (FSL) rats. Rats ingested CBD (30 mg/kg) orally. In the saccharin preference test, following a previous report of a pro-hedonic effect of CBD in male WKY, we now found similar results in female WKY. CBD also decreased immobility in the forced swim test in males (both strains) and in female WKY. These findings suggest a role for CBD in treating mental disorders with prominent symptoms of helplessness and anhedonia. © 2018 Elsevier Inc.
I.M. Linares, A.W. Zuardi, L.C. Pereira, R.H. Queiroz, R. Mechoulam, F.S. Guimarães, and J.A. Crippa. 2019. “Cannabidiol presents an inverted U-shaped dose-response curve in a simulated public speaking test.” Revista Brasileira de Psiquiatria, 41, 1, Pp. 9-14. Publisher's Version Abstract
Objective: Cannabidiol (CBD), one of the non-psychotomimetic compounds of Cannabis sativa, causes anxiolytic-like effects in animals, with typical bell-shaped dose-response curves. No study, however, has investigated whether increasing doses of this drug would also cause similar curves in humans. The objective of this study was to compare the acute effects of different doses of CBD and placebo in healthy volunteers performing a simulated public speaking test (SPST), a well-tested anxiety-inducing method. Method: A total of 57 healthy male subjects were allocated to receive oral CBD at doses of 150 mg (n=15), 300 mg (n=15), 600 mg (n=12) or placebo (n=15) in a double-blind procedure. During the SPST, subjective ratings on the Visual Analogue Mood Scale (VAMS) and physiological measures (systolic and diastolic blood pressure, heart rate) were obtained at six different time points. Results: Compared to placebo, pretreatment with 300 mg of CBD significantly reduced anxiety during the speech. No significant differences in VAMS scores were observed between groups receiving CBD 150 mg, 600 mg and placebo. Conclusion: Our findings confirm the anxiolytic-like properties of CBD and are consonant with results of animal studies describing bell-shaped dose-response curves. Optimal therapeutic doses of CBD should be rigorously determined so that research findings can be adequately translated into clinical practice. © 2019, Associacao Brasileira de Psiquiatria. All rights reserved.
G.N. Petrie, K.L. Wills, F. Piscitelli, R. Smoum, C.L. Limebeer, E.M. Rock, A.E. Humphrey, M. Sheppard-Perkins, A.H. Lichtman, R. Mechoulam, V. Di Marzo, and L.A. Parker. 2019. “Oleoyl glycine: interference with the aversive effects of acute naloxone-precipitated MWD, but not morphine reward, in male Sprague–Dawley rats.” Psychopharmacology, 236, 9, Pp. 2623-2633. Publisher's Version Abstract
Rationale: Oleoyl glycine (OlGly), a recently discovered fatty acid amide that is structurally similar to N- acylethanolamines, which include the endocannabinoid, anandamide (AEA), as well as endogenous peroxisome proliferator-activated receptor alpha (PPARα) agonists oleoylethanolamide (OEA) and palmitoylethanolamide (PEA), has been shown to interfere with nicotine reward and dependence in mice. Objectives and methods: Behavioral and molecular techniques were used to investigate the ability of OlGly to interfere with the affective properties of morphine and morphine withdrawal (MWD) in male Sprague–Dawley rats. Results: Synthetic OlGly (1–30 mg/kg, intraperitoneal [ip]) produced neither a place preference nor aversion on its own; however, at doses of 1 and 5 mg/kg, ip, it blocked the aversive effects of MWD in a place aversion paradigm. This effect was reversed by the cannabinoid 1 (CB1) receptor antagonist, AM251 (1 mg/kg, ip), but not the PPARα antagonist, MK886 (1 mg/kg, ip). OlGly (5 or 30 mg/kg, ip) did not interfere with a morphine-induced place preference or reinstatement of a previously extinguished morphine-induced place preference. Ex vivo analysis of tissue (nucleus accumbens, amygdala, prefrontal cortex, and interoceptive insular cortex) collected from rats experiencing naloxone-precipitated MWD revealed that OlGly was selectively elevated in the nucleus accumbens. MWD did not modify levels of the endocannabinoids 2-AG and AEA, nor those of the PPARα ligands, OEA and PEA, in any region evaluated. Conclusion: Here, we show that OlGly interferes with the aversive properties of acute naloxone-precipitated morphine withdrawal in rats. These results suggest that OlGly may reduce the impact of MWD and may possess efficacy in treating opiate withdrawal. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.
T. Stark, J. Ruda-Kucerova, F.A. Iannotti, C. D'Addario, R. Di Marco, V. Pekarik, E. Drazanova, F. Piscitelli, M. Bari, Z. Babinska, G. Giurdanella, M. Di Bartolomeo, S. Salomone, A. Sulcova, M. Maccarrone, C.T. Wotjak, Jr. Starcuk, Z., F. Drago, R. Mechoulam, V. Di Marzo, and V. Micale. 2019. “Peripubertal cannabidiol treatment rescues behavioral and neurochemical abnormalities in the MAM model of schizophrenia.” Neuropharmacology, 146, Pp. 212-221. Publisher's Version Abstract
In agreement with the neurodevelopmental hypothesis of schizophrenia, prenatal exposure of rats to the antimitotic agent methylazoxymethanol acetate (MAM) at gestational day 17 produced long-lasting behavioral alterations such as social withdrawal and cognitive impairment in the social interaction test and in the novel object recognition test, respectively. At the molecular level, an increased cannabinoid receptor type-1 (CB1) mRNA and protein expression, which might be due to reduction in DNA methylation at the gene promoter in the prefrontal cortex (PFC), coincided with deficits in the social interaction test and in the novel object recognition test in MAM rats. Both the schizophrenia-like phenotype and altered transcriptional regulation of CB1 receptors were reversed by peripubertal treatment (from PND 19 to PND 39) with the non-psychotropic phytocannabinoid cannabidiol (30 mg/kg/day), or, in part, by treatment with the cannabinoid CB1 receptor antagonist/inverse agonist AM251 (0.5 mg/kg/day), but not with haloperidol (0.6 mg/kg/day). These results suggest that early treatment with cannabidiol may prevent both the appearance of schizophrenia-like deficits as well as CB1 alterations in the PFC at adulthood, supporting that peripubertal cannabidiol treatment might be protective against MAM insult. © 2018 Elsevier Ltd
L. Bar-Lev Schleider, R. Mechoulam, N. Saban, G. Meiri, and V. Novack. 2019. “Real life Experience of Medical Cannabis Treatment in Autism: Analysis of Safety and Efficacy.” Scientific Reports, 9, 1. Publisher's Version Abstract
There has been a dramatic increase in the number of children diagnosed with autism spectrum disorders (ASD) worldwide. Recently anecdotal evidence of possible therapeutic effects of cannabis products has emerged. The aim of this study is to characterize the epidemiology of ASD patients receiving medical cannabis treatment and to describe its safety and efficacy. We analysed the data prospectively collected as part of the treatment program of 188 ASD patients treated with medical cannabis between 2015 and 2017. The treatment in majority of the patients was based on cannabis oil containing 30% CBD and 1.5% THC. Symptoms inventory, patient global assessment and side effects at 6 months were primary outcomes of interest and were assessed by structured questionnaires. After six months of treatment 82.4% of patients (155) were in active treatment and 60.0% (93) have been assessed; 28 patients (30.1%) reported a significant improvement, 50 (53.7%) moderate, 6 (6.4%) slight and 8 (8.6%) had no change in their condition. Twenty-three patients (25.2%) experienced at least one side effect; the most common was restlessness (6.6%). Cannabis in ASD patients appears to be well tolerated, safe and effective option to relieve symptoms associated with ASD. © 2019, The Author(s).
E. Murillo-Rodríguez, D. Millán-Aldaco, M. Palomero-Rivero, D. Morales-Lara, R. Mechoulam, and R. Drucker-Colín. 2019. “Cannabidiol partially blocks the excessive sleepiness in hypocretin-deficient rats: Preliminary data.” CNS and Neurological Disorders - Drug Targets, 18, 9, Pp. 705-712. Publisher's Version Abstract
Background: Excessive daytime sleepiness and cataplexy are among the symptoms of narcolepsy, a sleep disorder caused by the loss of hypocretin/orexin (HCRT/OX) neurons placed into the Hypothalamus (LH). Several treatments for managing narcolepsy include diverse drugs to induce alertness, such as antidepressants, amphetamine, or modafinil, etc. Recent evidence has shown that cannabidiol (CBD), a non-psychotropic derived from Cannabis sativa, shows positive therapeutic effects in neurodegenerative disorders, including Parkinson´s disease. Furthermore, CBD provokes alertness and enhances wake-related neurochemicals in laboratory animals. Thus, it is plausible to hypothesize that excessive somnolence observed in narcolepsy might be blocked by CBD. Objective: Here, we determined whether the systemic injection of CBD (5mg/kg, i.p.) would block the excessive sleepiness in a narcoleptic model. Methods: To test this idea, the neurotoxin hypocretin-2-saporin (HCRT2/SAP) was bilaterally injected into the LH of rats to eliminate HCRT leading to the establishment of narcoleptic-like behavior. Since excessive somnolence in HCRT2/SAP lesioned rats has been observed during the lights-off period, CBD was administered at the beginning of the dark phase. Results: Hourly analysis of sleep data showed that CBD blocked the sleepiness during the lights-off period across 7h post-injection in lesioned rats. Conclusion: Taking together, these preliminary findings suggest that CBD might prevent sleepiness in narcolepsy. © 2019 Bentham Science Publishers.

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