Role of the endocannabinoid and endovanilloid systems in an animal model of schizophrenia-related emotional processing/cognitive deficit.


“Studies suggest that the endocannabinoid and endovanilloid systems are implicated in the pathophysiology of schizophrenia.

The Spontaneously Hypertensive Rats (SHR) strain displays impaired contextual fear conditioning (CFC) attenuated by antipsychotic drugs and worsened by pro-psychotic manipulations. Therefore, SHR strain is used to study emotional processing/associative learning impairments associated with schizophrenia and effects of potential antipsychotic drugs.

Here, we evaluated the expression of CB1 and TRPV1 receptors in some brain regions related to the pathophysiology of schizophrenia. We also assessed the effects of drugs that act on the endocannabinoid/endovanilloid systems on the CFC task in SHRs and control animals (Wistar rats – WRs).

These results reinforce the involvement of the endocannabinoid/endovanilloid systems in the SHRs CFC deficit and point to these systems as targets to treat the emotional processing/cognitive symptoms of schizophrenia.”

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Diverse TRPV1 responses to cannabinoids.

 Publication Cover“Cannabinoid compounds are potential analgesics. Users of medicinal Cannabis report efficacy for pain control, clinical studies show that cannabis can be effective and opioid sparing in chronic pain, and some constituent cannabinoids have been shown to target nociceptive ion channels. Here, we explore and compare a suite of cannabinoids for their impact upon the physiology of TRPV1. The cannabinoids tested evoke differential responses in terms of kinetics of activation and inactivation. Cannabinoid activation of TRPV1 displays significant dependence on internal and external calcium levels. Cannabinoid activation of TRPV1 does not appear to induce the highly permeant, pore-dilated channel state seen with Capsaicin, even at high current amplitudes. Finally, we analyzed cannabinoid responses at nocioceptive channels other than TRPV1 (TRPV2, TRPM8 and TRPA1), and report that cannabinoids differentially activate these channels. On the basis of response activation and kinetics, state-selectivity and receptor selectivity, it may be possible to rationally design approaches to pain using single or multiple cannabinoids.”

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The Endocannabinoid/Endovanilloid System in Bone: From Osteoporosis to Osteosarcoma.


“Bone is a dynamic tissue, whose homeostasis is maintained by a fine balance between osteoclast (OC) and osteoblast (OB) activity. The endocannabinoid/endovanilloid (EC/EV) system’s receptors are the cannabinoid receptor type 1 (CB1), the cannabinoid receptor type 2 (CB2), and the transient receptor potential cation channel subfamily V member 1 (TRPV1). Their stimulation modulates bone formation and bone resorption. Bone diseases are very common worldwide. Osteoporosis is the principal cause of bone loss and it can be caused by several factors such as postmenopausal estrogen decrease, glucocorticoid (GC) treatments, iron overload, and chemotherapies. Studies have demonstrated that CB1 and TRPV1 stimulation exerts osteoclastogenic effects, whereas CB2 stimulation has an anti-osteoclastogenic role. Moreover, the EC/EV system has been demonstrated to have a role in cancer, favoring apoptosis and inhibiting cell proliferation. In particular, in bone cancer, the modulation of the EC/EV system not only reduces cell growth and enhances apoptosis but it also reduces cell invasion and bone pain in mouse models. Therefore, EC/EV receptors may be a useful pharmacological target in the prevention and treatment of bone diseases. More studies to better investigate the biochemical mechanisms underlining the EC/EV system effects in bone are needed, but the synthesis of hybrid molecules, targeting these receptors and capable of oppositely regulating bone homeostasis, seems to be a promising and encouraging prospective in bone disease management.”

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Anticonvulsant effect of cannabidiol in the pentylenetetrazole model: Pharmacological mechanisms, electroencephalographic profile, and brain cytokine levels.

“Cannabidiol (CBD), the main nonpsychotomimetic compound from Cannabis sativa, inhibits experimental seizures in animal models and alleviates certain types of intractable epilepsies in patients.

Here we tested the hypothesis that CBD anticonvulsant mechanisms are prevented by cannabinoid (CB1 and CB2) and vanilloid (TRPV1) receptor blockers. We also investigated its effects on electroencephalographic (EEG) activity and hippocampal cytokines in the pentylenetetrazole (PTZ) model.

Pretreatment with CBD (60mg/kg) attenuated seizures induced by intraperitoneal, subcutaneous, and intravenous PTZ administration in mice. The effects were reversed by CB1, CB2, and TRPV1 selective antagonists (AM251, AM630, and SB366791, respectively). Additionally, CBD delayed seizure sensitization resulting from repeated PTZ administration (kindling). This cannabinoid also prevented PTZ-induced EEG activity and interleukin-6 increase in prefrontal cortex.

In conclusion, the robust anticonvulsant effects of CBD may result from multiple pharmacological mechanisms, including facilitation of endocannabinoid signaling and TRPV1 mechanisms. These findings advance our understanding on CBD inhibition of seizures, EEG activity, and cytokine actions, with potential implications for the development of new treatments for certain epileptic syndromes.”

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Endocannabinoid analogues exacerbate marble-burying behavior in mice via TRPV1 receptor.

“Activation of cannabinoid CB(1) receptor is shown to inhibit marble-burying behavior (MBB), a behavioral model for assessing obsessive-compulsive disorder (OCD).

Anandamide, an endogenous agonist at CB(1) receptor also activates the transient receptor potential vanilloid type 1 (TRPV1) channels but at a higher concentration.

Furthermore, anandamide-mediated TRPV1 effects are opposite to that of the CB(1) receptor. Therefore, the present study was carried out to investigate the influence of low and high doses of anandamide on MBB in CB(1) and TRPV1 antagonist pre-treated mice.

Thus, the study indicates the biphasic influence of anandamide on MBB, and chronic administration of capsazepine either alone or with URB597 might be an effective tool in the treatment of OCD.”

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Cannabinoid-based drugs targeting CB1 and TRPV1, the sympathetic nervous system, and arthritis.

“Chronic inflammation in rheumatoid arthritis (RA) is accompanied by activation of the sympathetic nervous system, which can support the immune system to perpetuate inflammation. Several animal models of arthritis already demonstrated a profound influence of adrenergic signaling on the course of RA.

Peripheral norepinephrine release from sympathetic terminals is controlled by cannabinoid receptor type 1 (CB1), which is activated by two major endocannabinoids (ECs), arachidonylethanolamine (anandamide) and 2-arachidonylglycerol.

These ECs also modulate function of transient receptor potential channels (TRPs) located on sensory nerve fibers, which are abundant in arthritic synovial tissue. TRPs not only induce the sensation of pain but also support inflammation via secretion of pro-inflammatory neuropeptides.

In addition, many cell types in synovial tissue express CB1 and TRPs.

In this review, we focus on CB1 and transient receptor potential vanilloid 1 (TRPV1)-mediated effects on RA since most anti-inflammatory mechanisms induced by cannabinoids are attributed to cannabinoid receptor type 2 (CB2) activation.

We demonstrate how CB1 agonism or antagonism can modulate arthritic disease.

The concept of functional antagonism with continuous CB1 activation is discussed.

Since fatty acid amide hydrolase (FAAH) is a major EC-degrading enzyme, the therapeutic possibility of FAAH inhibition is studied.

Finally, the therapeutic potential of ECs is examined since they interact with cannabinoid receptors and TRPs but do not produce central side effects.”

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Endocannabinoids activate transient receptor potential vanilloid 1 receptors to reduce hyperdopaminergia-related hyperactivity: therapeutic implications.

“Knockout (KO) mice invalidated for the dopamine transporter (DAT) constitute a powerful animal model of neurobiological alterations associated with hyperdopaminergia relevant to schizophrenia and attention-deficit/hyperactivity disorder (ADHD).


These data indicate a dysregulated striatal endocannabinoid neurotransmission associated with hyperdopaminergic state.

Restoring endocannabinoid homeostasis in active synapses might constitute an alternative therapeutic strategy for disorders associated with hyperdopaminergia.

In this process, TRPV1 receptors seem to play a key role and represent a novel promising pharmacological target.”

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The interactive role of cannabinoid and vanilloid systems in hippocampal synaptic plasticity in rats.

“Long-term potentiation (LTP) has been most thoroughly studied in the hippocampus, which has a key role in learning and memory. Endocannabinoids are one of the endogenous systems that modulate this kind of synaptic plasticity. The activation of the vanillioid system has also been shown to mediate synaptic plasticity in the hippocampus. In addition, immunohistochemical studies have shown that cannabinoid receptor type 1 (CB1) and vanilloid receptor 1 (TRPV1) are closely located in the hippocampus.

It seems that agonists of the vanilloid system modulate cannabinoid outputs that cause an increase in synaptic plastisity, while in contemporary consumption of two agonist, TRPV1 agonist can change production of endocannabinoid, which in turn result to enhancement of LTP induction. These findings suggest that the two systems may interact or share certain common signaling pathways in the hippocampus.”

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Palmitoylethanolamide: From endogenous cannabimimetic substance to innovative medicine for the treatment of cannabis dependence.

“Palmitoylethanolamide (PEA) is a fatty acid amide showing some pharmacodynamic similarities with Δ9-tetrahydrocannabinol, the principal psychoactive compound present in the cannabis plant.

Like Δ9-tetrahydrocannabinol, PEA can produce a direct or indirect activation of cannabinoid receptors.

 Furthermore, it acts as an agonist at TRPV1 receptor.

The hypothesis is that PEA has anti-craving effects in cannabis dependent patients, is efficacious in the treatment of withdrawal symptoms, produces a reduction of cannabis consumption and is effective in the prevention of cannabis induced neurotoxicity and neuro-psychiatric disorders.”

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Role of cannabinoid and vanilloid receptors in invasion of human breast carcinoma cells.

“It is known that the diversified effects of cannabinoid on the fate of carcinoma cells are mediated predominantly through receptors. However, little is known about the effects of the individual activities of cannabinoid and noncannabinoid receptors. Here we investigate the role of cannabinoid receptor (CB) 1, CB2, and transient receptor potential vanilloid type 1 in cell proliferation and invasion patterns in the MDA-MB-231 cell line.

Our results showed that activation of CB1 and vanilloid receptors by methanandamide, a nonselective agonist, and arachidonyl-2′-choloroethylamide (ACEA) and N-oleoyldopamine, selective agonists, reduced invasion of MDA-MB-231 cells at pharmacological concentrations. Accordingly, CB1 activation resulted in decreased expression of matrix metalloproteinase (MMP) 2. On the other hand, administration of a CB2 agonist (CB65) increased cell invasion and expression of MMP2. The data obtained from MTT assay did not show any correlation between reduced invasion and cytotoxic effects of drugs. In addition, the level of vascular endothelial growth factor was significantly reduced in treatment with (R)-(+)-methanandamide, ACEA, CB65, and AM251 (a potent agonist for GPR55 and selective antagonist of CB1) compared with control. Elevated expression of cyclooxygenase-2 was observed in all of the MDA-MB-231 cells treated with agonists.

These results underline the influence of cannabinoid and vanilloid receptors on the invasiveness of MDA-MB-231 human breast carcinoma cells.”

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