Cannabidiol-induced panicolytic-like effects and fear-induced antinociception impairment: the role of the CB1 receptor in the ventromedial hypothalamus.

Image result for Springer Link“The behavioural effects elicited by chemical constituents of Cannabis sativa, such as cannabidiol (CBD), on the ventromedial hypothalamus (VMH) are not well understood. There is evidence that VMH neurons play a relevant role in the modulation of unconditioned fear-related defensive behavioural reactions displayed by laboratory animals.

OBJECTIVES:

This study was designed to explore the specific pattern of distribution of the CB1 receptors in the VMH and to investigate the role played by this cannabinoid receptor in the effect of CBD on the control of defensive behaviours and unconditioned fear-induced antinociception.

METHODS:

A panic attack-like state was triggered in Wistar rats by intra-VMH microinjections of N-methyl-D-aspartate (NMDA). One of three different doses of CBD was microinjected into the VMH prior to local administration of NMDA. In addition, the most effective dose of CBD was used after pre-treatment with the CB1 receptor selective antagonist AM251, followed by NMDA microinjections in the VMH.

RESULTS:

The morphological procedures demonstrated distribution of labelled CB1 receptors on neuronal perikarya situated in dorsomedial, central and ventrolateral divisions of the VMH. The neuropharmacological approaches showed that both panic attack-like behaviours and unconditioned fear-induced antinociception decreased after intra-hypothalamic microinjections of CBD at the highest dose (100 nmol). These effects, however, were blocked by the administration of the CB1 receptor antagonist AM251 (100 pmol) in the VMH.

CONCLUSION:

These findings suggest that CBD causes panicolytic-like effects and reduces unconditioned fear-induced antinociception when administered in the VMH, and these effects are mediated by the CB1 receptor-endocannabinoid signalling mechanism in VMH.”

https://www.ncbi.nlm.nih.gov/pubmed/31919563

https://link.springer.com/article/10.1007%2Fs00213-019-05435-5

“panicolytic: That reduces the flight reflex in animals when faced with danger. Any drug that has this effect.” https://en.wiktionary.org/wiki/panicolytic

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Isolation of a High-Affinity Cannabinoid for the Human CB1 Receptor from a Medicinal Cannabis sativa Variety: Δ9-Tetrahydrocannabutol, the Butyl Homologue of Δ9-Tetrahydrocannabinol.

Go to Volume 0, Issue 0“The butyl homologues of Δ9-tetrahydrocannabinol, Δ9-tetrahydrocannabutol (Δ9-THCB), and cannabidiol, cannabidibutol (CBDB), were isolated from a medicinal Cannabis sativa variety (FM2) inflorescence. Appropriate spectroscopic and spectrometric characterization, including NMR, UV, IR, ECD, and HRMS, was carried out on both cannabinoids. The chemical structures and absolute configurations of the isolated cannabinoids were confirmed by comparison with the spectroscopic data of the respective compounds obtained by stereoselective synthesis. The butyl homologue of Δ9-THC, Δ9-THCB, showed an affinity for the human CB1 (Ki = 15 nM) and CB2 receptors (Ki = 51 nM) comparable to that of (-)-trans9-THC. Docking studies suggested the key bonds responsible for THC-like binding affinity for the CB1 receptor. The formalin test in vivo was performed on Δ9-THCB in order to reveal possible analgesic and anti-inflammatory properties. The tetrad test in mice showed a partial agonistic activity of Δ9-THCB toward the CB1 receptor.”

https://www.ncbi.nlm.nih.gov/pubmed/31891265

https://pubs.acs.org/doi/abs/10.1021/acs.jnatprod.9b00876

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Stress-induced modulation of endocannabinoid signaling leads to delayed strengthening of synaptic connectivity in the amygdala.

Image result for pnas“Even a brief exposure to severe stress strengthens synaptic connectivity days later in the amygdala, a brain area implicated in the affective symptoms of stress-related psychiatric disorders. However, little is known about the synaptic signaling mechanisms during stress that eventually culminate in its delayed impact on the amygdala. Hence, we investigated early stress-induced changes in amygdalar synaptic signaling in order to prevent its delayed effects.

Whole-cell recordings in basolateral amygdala (BLA) slices from rats revealed higher frequency of miniature excitatory postsynaptic currents (mEPSCs) immediately after 2-h immobilization stress. This was replicated by inhibition of cannabinoid receptors (CB1R), suggesting a role for endocannabinoid (eCB) signaling.

Stress also reduced N-arachidonoylethanolamine (AEA), an endogenous ligand of CB1R. Since stress-induced activation of fatty acid amide hydrolase (FAAH) reduces AEA, we confirmed that oral administration of an FAAH inhibitor during stress prevents the increase in synaptic excitation in the BLA soon after stress.

Although stress also caused an immediate reduction in synaptic inhibition, this was not prevented by FAAH inhibition. Strikingly, FAAH inhibition during the traumatic stressor was also effective 10 d later on the delayed manifestation of synaptic strengthening in BLA neurons, preventing both enhanced mEPSC frequency and increased dendritic spine-density.

Thus, oral administration of an FAAH inhibitor during a brief stress prevents the early synaptic changes that eventually build up to hyperexcitability in the amygdala. This framework is of therapeutic relevance because of growing interest in targeting eCB signaling to prevent the gradual development of emotional symptoms and underlying amygdalar dysfunction triggered by traumatic stress.”

https://www.ncbi.nlm.nih.gov/pubmed/31843894

https://www.pnas.org/content/early/2019/12/13/1910322116

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Gastrointestinal Adverse Events of Cannabinoid 1 Receptor Inverse Agonists suggest their Potential Use in Irritable Bowel Syndrome with Constipation: A Systematic Review and Meta-Analysis.

 Image result for J Gastrointestin Liver Dis“Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal (GI) disorders characterized by pain and impaired bowel movements. Currently available drugs show limited efficacy.

Cannabinoid 1 receptor (CB1) inverse agonists (CB1-RAN) cause diarrhea and may be candidates for the treatment of constipation-predominant IBS (IBS-C). We evaluated the effects of CB1-RAN in clinical trials for their potential use in IBS-C.

METHODS:

Database search identified all clinical trials published up to May 2018 that reported rimonabant and taranabant treatment for at least one month and detailed the GI adverse events (AEs). Categorical outcomes (subgroups of AEs) were analyzed using the odds ratio (OR).

RESULTS:

Eighteen trials met the inclusion criteria. Rimonabant 20 mg produced significantly more overall AEs (OR=1.35, CI: 1.19-1.52, p<0.0001), psychiatric events (OR=1.79, CI: 1.46-2.21, p<0.001) and GI AEs (OR=2.05, CI: 1.65-2.55, p<0.001) compared to placebo. Taranabant at doses ranging from 0.5 to 8 mg produced significantly more overall AEs (OR=1.36, CI: 1.13-1.64, p<0.002), psychiatric AEs (1.82, CI: 1.54-2.16, p<0.001) and GI AEs (OR=1.75, CI: 1.29-2.37, p<0.001) compared to placebo.

CONCLUSIONS:

The approach to target CB1 in the gut for the treatment of IBS-C or chronic constipation seems a promising therapeutic option. Prospective clinical trials on the possible targeting of CB1 and the endocannabinoid system are warranted.”

https://www.ncbi.nlm.nih.gov/pubmed/31826058

https://www.jgld.ro/jgld/index.php/jgld/article/view/265

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Vasodilatory effects of cannabidiol in human pulmonary and rat small mesenteric arteries: modification by hypertension and the potential pharmacological opportunities.

 Image result for ovid journal“Cannabidiol (CBD) has been suggested as a potential antihypertensive drug.

The aim of our study was to investigate its vasodilatory effect in isolated human pulmonary arteries (hPAs) and rat small mesenteric arteries (sMAs).

METHODS:

Vascular effects of CBD were examined in hPAs obtained from patients during resection of lung carcinoma and sMAs isolated from spontaneously hypertensive (SHR); 11-deoxycorticosterone acetate (DOCA-salt) hypertensive rats or their appropriate normotensive controls using organ bath and wire myography, respectively.

RESULTS:

CBD induced almost full concentration-dependent vasorelaxation in hPAs and rat sMAs. In hPAs, it was insensitive to antagonists of CB1 (AM251) and CB2 (AM630) receptors but it was reduced by endothelium denudation, cyclooxygenase inhibitors (indomethacin and nimesulide), antagonists of prostanoid EP4 (L161982), IP (Cay10441), vanilloid TRPV1 (capsazepine) receptors and was less potent under KCl-induced tone and calcium-activated potassium channel (KCa) inhibitors (iberiotoxin, UCL1684 and TRAM-34) and in hypertensive, overweight and hypercholesteremic patients. The time-dependent effect of CBD was sensitive to the PPARγ receptor antagonist GW9662. In rats, the CBD potency was enhanced in DOCA-salt and attenuated in SHR. The CBD-induced relaxation was inhibited in SHR and DOCA-salt by AM251 and only in DOCA-salt by AM630 and endothelium denudation.

CONCLUSION:

The CBD-induced relaxation in hPAs that was reduced in hypertensive, obese and hypercholesteremic patients was endothelium-dependent and mediated via KCa and IP, EP4, TRPV1 receptors. The CBD effect in rats was CB1-sensitive and dependent on the hypertension model. Thus, modification of CBD-mediated responses in disease should be considered when CBD is used for therapeutic purposes.”

https://www.ncbi.nlm.nih.gov/pubmed/31800399

https://insights.ovid.com/crossref?an=00004872-900000000-97067

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The role of the endocannabinoid system in aetiopathogenesis of endometriosis: A potential therapeutic target.

European Journal of Obstetrics and Gynecology Home“Endometriosis affects a large proportion of women during their reproductive years and is associated with pain and infertility, also affecting psychological wellbeing and quality of life. The pathogenesis of the disease remains unclear, although it is believed to be multifactorial.

The endocannabinoid system (ECS) consists of a number of ligands, receptors and enzymes, and has gained interests in endometriosis research. This review aims to summarise all available evidence reporting the roles of the ECS in endometriosis.

A literature search of the PubMed, EMBASE, and Web of Science electronic medical databases was performed. Original and review articles published in peer-reviewed journals were included. No publication date or publication status restrictions were imposed.

Significant differences in the concentrations and expressions of the components of the ECS were reported in the eutopic and ectopic endometrium, and the systemic circulation of women with endometriosis compared to controls. Endometriosis appears to be associated with downregulation of CB1 receptors and upregulation of TRPV1 receptors.

The role of CB1 and progesterone in anti-inflammatory action and the role of TRPV1 in inflammation and pain are of particular interests. Furthermore, the ECS has been reported to be involved in processes relevant to endometriosis, including cell migration, cell proliferation, apoptosis, inflammation, and interacts with sex steroid hormones.

The ECS may play a role in disease establishment, progression, and pain in endometriosis. However, reports are based on studies of limited size and there are inconsistencies among the definition of their control groups. There are also conflicting reports regarding precise involvement of the ECS in endometriosis. Future research with larger numbers, strict inclusion and exclusion criteria and detailed clinical information is imperative.”

https://www.ncbi.nlm.nih.gov/pubmed/31785471

https://www.ejog.org/article/S0301-2115(19)30526-3/fulltext

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Alcohol Binge-Induced Cardiovascular Dysfunction Involves Endocannabinoid-CB1-R Signaling.

 JACC: Basic to Translational Science“Excessive binge alcohol drinking may adversely affect cardiovascular function. In this study we characterize the detailed hemodynamic effects of an acute alcohol binge in mice using multiple approaches and investigate the role of the endocannabinoid-cannabinoid 1 receptor (CB1-R) signaling in these effects. Acute alcohol binge was associated with elevated levels of cardiac endocannabinoid anandamide and profound cardiovascular dysfunction lasting for several hours and redistribution of circulation. These changes were attenuated by CB1-R antagonist or in CB1-R knockout mice. Our results suggest that a single alcohol binge has profound effects on the cardiovascular system, which involve endocannabinoid-CB1-R signaling.”

https://www.ncbi.nlm.nih.gov/pubmed/31768478

“Alcohol is one of the most frequently used intoxicants in the United States. Binge alcohol drinking is a major contributor of emergency department visits. Binge alcohol drinking may adversely affect cardiovascular function. Here we show that acute alcohol intoxication is associated with elevated levels of cardiac endocannabinoid anandamide and profound cardiovascular dysfunction and blood redistribution lasting for several hours. The adverse cardiovascular effects of acute alcohol intoxication are attenuated by CB1-R antagonist or in CB1-R knockout mice. A single alcohol binge has profound effect on the cardiovascular system, which involves endocannabinoid-CB1-R signaling.”

https://www.sciencedirect.com/science/article/pii/S2452302X19301755?via%3Dihub

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Δ9-THC and related cannabinoids suppress substance P- induced neurokinin NK1-receptor-mediated vomiting via activation of cannabinoid CB1 receptor.

European Journal of Pharmacology

“Δ9-THC suppresses cisplatin-induced vomiting through activation of cannabinoid CB1 receptors.

Cisplatin-evoked emesis is predominantly due to release of serotonin and substance P (SP) in the gut and the brainstem which subsequently stimulate their corresponding 5-HT3-and neurokinin NK1-receptors to induce vomiting. Δ9-THC can inhibit vomiting caused either by the serotonin precursor 5-HTP, or the 5-HT3 receptor selective agonist, 2-methyserotonin.

In the current study, we explored whether Δ9-THC and related CB1/CB2 receptor agonists (WIN55,212-2 and CP55,940) inhibit vomiting evoked by SP (50 mg/kg, i.p.) or the NK1 receptor selective agonist GR73632 (5 mg/kg, i.p.). Behavioral methods were employed to determine the antiemetic efficacy of cannabinoids in least shrews.

Our results showed that administration of varying doses of Δ9-THC (i.p. or s.c.), WIN55,212-2 (i.p.), or CP55,940 (i.p.) caused significant suppression of SP-evoked vomiting in a dose-dependent manner. When tested against GR73632, Δ9-THC also dose-dependently reduced the evoked emesis.

The antiemetic effect of Δ9-THC against SP-induced vomiting was prevented by low non-emetic doses of the CB1 receptor inverse-agonist/antagonist SR141716A (<10 mg/kg). We also found that the NK1 receptor antagonist netupitant can significantly suppress vomiting caused by a large emetic dose of SR141716A (20 mg/kg).

In sum, Δ9-THC and related cannabinoids suppress vomiting evoked by the nonselective (SP) and selective (GR73632) neurokinin NK1 receptor agonists via stimulation of cannabinoid CB1 receptors.”

https://www.ncbi.nlm.nih.gov/pubmed/31738934

https://www.sciencedirect.com/science/article/pii/S0014299919307587?via%3Dihub

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Relieving tension: effects of cannabinoids on vagal afferent sensitivity.

Publication cover image“Endocannabinoids are produced within the gastrointestinal (GI) tract and modulate energy homeostasis and food intake, at least in part, via vagally-dependent actions. The recent paper by Christie et al., [Christie, et al. J Physiol, 2019] demonstrate, for the first time, that cannabinoids exert biphasic effects on the mechanosensitivity of tension-sensitive gastric vagal afferents. At higher concentrations, anandamide increased vagal afferent sensitivity in a CB1 and TRPV1 receptor dependent manner. At lower concentrations, however, anandamide decreased afferent mechanosensitivity; while this was also dependent upon CB1 and TRPV1 receptors, it also appeared dependent upon signaling via the potent orexigenic neurohormone, ghrelin. These results provide further evidence to support the remarkable degree of neuroplasticity within vagal afferent signaling, and suggest that untangling the complex interactions of cannabinoid effects on food intake and energy homeostasis will require careful physiological and pharmacological investigations.”

https://www.ncbi.nlm.nih.gov/pubmed/31707736

https://physoc.onlinelibrary.wiley.com/doi/abs/10.1113/JP279173

“A clear understanding of the mechanisms which mediate these events may provide novel therapeutic targets for the treatment of gastrointestinal disorders due to vago-vagal pathway malfunctions.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6318799/

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Cannabidiol increases the nociceptive threshold in a preclinical model of Parkinson’s disease.

Neuropharmacology

“Medications that improve pain threshold can be useful in the pharmacotherapy of Parkinson’s disease (PD). Pain is a prevalent PD’s non-motor symptom with a higher prevalence of analgesic drugs prescription for patients. However, specific therapy for PD-related pain are not available.

Since the endocannabinoid system is expressed extensively in different levels of pain pathway, drugs designed to target this system have promising therapeutic potential in the modulation of pain. Thus, we examined the effects of the 6-hydroxydopamine- induced PD on nociceptive responses of mice and the influence of cannabidiol (CBD) on 6-hydroxydopamine-induced nociception.

Further, we investigated the pathway involved in the analgesic effect of the CBD through the co-administration with a fatty acid amide hydrolase (FAAH) inhibitor, increasing the endogenous anandamide levels, and possible targets from anandamide, i.e., the cannabinoid receptors subtype 1 and 2 (CB1 and CB2) and the transient receptor potential vanilloid type 1 (TRPV1).

We report that 6-hydroxydopamine- induced parkinsonism decreases the thermal and mechanical nociceptive threshold, whereas CBD (acute and chronic treatment) reduces this hyperalgesia and allodynia evoked by 6-hydroxydopamine. Moreover, ineffective doses of either FAAH inhibitor or TRPV1 receptor antagonist potentialized the CBD-evoked antinociception while an inverse agonist of the CB1 and CB2 receptor prevented the antinociceptive effect of the CBD.

Altogether, these results indicate that CBD can be a useful drug to prevent the parkinsonism-induced nociceptive threshold reduction. They also suggest that CB1 and TRPV1 receptors are important for CBD-induced analgesia and that CBD could produce these analgesic effects increasing endogenous anandamide levels.”

https://www.ncbi.nlm.nih.gov/pubmed/31706993

“The CBD treatment decreases hyperalgesia and allodynia in experimental parkinsonism.”

https://www.sciencedirect.com/science/article/pii/S0028390819303703?via%3Dihub

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