Tag Archives: anticonvulsant

Cannabinoids: is there a potential treatment role in epilepsy?

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“Cannabinoids have been used medicinally for centuries, and in the last decade, attention has focused on their broad therapeutic potential particularly in seizure management.

While some cannabinoids have demonstrated anticonvulsant activity in experimental studies, their efficacy for managing clinical seizures has not been fully established.

This commentary will touch on our understanding of the brain endocannabinoid system’s regulation of synaptic transmission in both physiological and pathophysiological conditions, and review the findings from both experimental and clinical studies on the effectiveness of cannabinoids to suppress epileptic seizures.

At present, there is preliminary evidence that non-psychoactive cannabinoids may be useful as anticonvulsants, but additional clinical trials are needed to fully evaluate the efficacy and safety of these compounds for the treatment of epilepsy.”

http://www.ncbi.nlm.nih.gov/pubmed/26234319

Interaction between Cannabinoid Compounds and Capsazepine in Protection against Acute Pentylenetetrazole-induced Seizure in Mice.

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“The pharmacological interaction between cannabinoidergic system and vanilloid type 1 (TRPV1) channels has been investigated in various conditions such as pain and anxiety.

In some brain structure including hippocampus, CB1 and TRPV1 receptors coexist and their activation produces opposite effect on excitability of neurons.

In this study, we tested the hypothesis that TRPV1 channel is involved in the modulation of cannabinoid effects on pentylenetetrazole (PTZ)-induced seizure threshold…

The anticonvulsant actions of both capsazepine and ACEA were attenuated after co-administration of these compounds. Moreover, the anticonvulsant action of capsazepine was attenuated after co-administration with VDM11.

The results suggest an interaction between cannabinoidergic system and TRPV1 receptors in protection against acute PTZ-induced seizure in mice.”

http://www.ncbi.nlm.nih.gov/pubmed/26185513

Antiepileptic potential of cannabidiol analogs.

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“In audiogenic seizure (AGS) susceptible rats, the acute (intraperitoneal and intravenous) dose-response effects of (–)-cannabidiol (CBD) for preventing AGS and for causing rototod neurotoxicity (ROT) were determined.

Also, the anti-AGS and ROT effects of 10 CBD analogs, given in intravenous doses equivalent to the AGS-ED50 (15 mg/kg) and ROT-ID50 (31 mg/kg) of CBD, were ascertained.

Compared to CBD, (–)-CBD diacetate and (–)-4-(2′-olivetyl)-alpha-pinene were equally effective whereas (–)-CBD monomethyl ether, (–)-CBD dimethyl ether, (–)-3′-acetyl-CBD monoacetate, (+)-4-(2′-olivetyl)-alpha-pinene, (–)-and (+)-4-(6′-olivetyl)-alpha-pinene, (+/-)-AF-11, and olivetol were less effective anticonvulsants. Except for (–)- and (+)-4-(2′-olivetyl)-alpha-pinene and olivetol, all analogs showed less ROT than CBD.

Also, CBD and all analogs were not active in tetrahydrocannabinol seizure-susceptible rabbits, the latter a putative model of cannabinoid psychoactivity in humans.

These data suggest anticonvulsant requirements of 2 free phenolic hydroxyl groups, exact positioning of the terpinoid moiety in the resorcinol system and correct stereochemistry.

Moreover, findings of separation of anticonvulsant from neurotoxic and psychoactive activities, notably with CBD diacetate, suggest that additional structural modifications of CBD may yield novel antiepileptic drugs.”

http://www.ncbi.nlm.nih.gov/pubmed/7298873

http://www.thctotalhealthcare.com/category/epilepsy-2/

Phytocannabinoids and epilepsy.

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“Antiepileptic drugs often produce serious adverse effects, and many patients do not respond to them properly.

Phytocannabinoids produce anticonvulsant effects in preclinical and preliminary human studies, and appear to produce fewer adverse effects than available antiepileptic drugs.

The present review summarizes studies on the anticonvulsant properties of phytocannabinoids.

Preclinical studies suggest that phytocannabinoids, especially cannabidiol and cannabidivarin, have potent anticonvulsant effects which are mediated by the endocannabinoid system. Human studies are limited in number and quality, but suggest that cannabidiol has anticonvulsant effects in adult and infantile epilepsy and is well tolerated after prolonged administration…

 

Phytocannabinoids produce anticonvulsant effects through the endocannabinoid system, with few adverse effects.”

http://www.ncbi.nlm.nih.gov/pubmed/25475762

http://www.thctotalhealthcare.com/category/epilepsy-2/

The non-psychotropic plant cannabinoids, cannabidivarin (CBDV) and cannabidiol (CBD), activate and desensitize transient receptor potential vanilloid 1 (TRPV1) channels in vitro: potential for the treatment of neuronal hyperexcitability.

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“Epilepsy is the most common neurological disorder, with over 50 million people worldwide affected. Recent evidence suggests that the transient receptor potential cation channel subfamily V member 1 (TRPV1) may contribute to the onset and progression of some forms of epilepsy.

Since the two non-psychotropic cannabinoids cannabidivarin (CBDV) and cannabidiol (CBD) exert anticonvulsant activity in vivo and produce TRPV1-mediated intracellular calcium elevation in vitro, we evaluated the effects of these two compounds on TRPV1 channel activation and desensitization and in an in vitro model of epileptiform activity.

These data suggest that CBDV anti-epileptiform effects in the Mg2+-free model are not uniquely mediated via activation of TRPV1. However, TRPV1 was strongly phosphorylated (and hence likely sensitized) in Mg2+-free solution-treated hippocampal tissue, and both capsaicin and CBDV caused TRPV1 dephosphorylation, consistent with TRPV1 desensitization. We propose that CBDV effects on TRP channels should be studied further in different in vitro and in vivo models of epilepsy.”

http://www.ncbi.nlm.nih.gov/pubmed/25029033

The case for assessing cannabidiol in epilepsy.

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“Intractable epilepsies have an extraordinary impact on cognitive and behavioral function and quality of life, and the treatment of seizures represents a challenge and a unique opportunity. Over the past few years, considerable attention has focused on cannabidiol (CBD), the major nonpsychotropic compound of Cannabis sativa.

Basic research studies have provided strong evidence for safety and anticonvulsant properties of CBD. However, the lack of pure, pharmacologically active compounds and legal restrictions have prevented clinical research and confined data on efficacy and safety to anecdotal reports.

Pure CBD appears to be an ideal candidate among phytocannabinoids as a therapy for treatment-resistant epilepsy.

A first step in this direction is to systematically investigate the safety, pharmacokinetics, and interactions of CBD with other antiepileptic drugs and obtain an initial signal regarding efficacy at different dosages. These data can then be used to plan double-blinded placebo-controlled efficacy trials.”

http://www.ncbi.nlm.nih.gov/pubmed/24854434

http://www.thctotalhealthcare.com/category/epilepsy-2/

Effects of WIN 55,212-2 (a non-selective cannabinoid CB1 and CB 2 receptor agonist) on the protective action of various classical antiepileptic drugs in the mouse 6 Hz psychomotor seizure model.

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“The aim of this study was to characterize the influence of WIN 55,212-2 (WIN-a non-selective cannabinoid CB1 and CB2 receptor agonist) on the anticonvulsant effects of various classical antiepileptic drugs (clobazam, clonazepam, phenobarbital and valproate) in the mouse 6 Hz-induced psychomotor seizure model…

These preclinical data would suggest that WIN in combination with clonazepam, phenobarbital and valproate is associated with beneficial anticonvulsant pharmacodynamic interactions in the mouse 6 Hz-induced psychomotor seizure test.”

http://www.ncbi.nlm.nih.gov/pubmed/24549572

Cannabidivarin (CBDV) suppresses pentylenetetrazole (PTZ)-induced increases in epilepsy-related gene expression.

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“To date, anticonvulsant effects of the plant cannabinoid, cannabidivarin (CBDV), have been reported in several animal models of seizure. However, these behaviourally observed anticonvulsant effects have not been confirmed at the molecular level…

These results provide the first molecular confirmation of behaviourally observed effects of the non-psychoactive, anticonvulsant cannabinoid, CBDV, upon chemically-induced seizures and serve to underscore its suitability for clinical development.”

http://www.ncbi.nlm.nih.gov/pubmed/24282673

Full-text: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3840466/

Cannabidivarin-rich cannabis extracts are anticonvulsant in mouse and rat via a CB1 receptor-independent mechanism.

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“Epilepsy is the most prevalent neurological disease and is characterised by recurrent seizures. Here we investigate: (i) the anticonvulsant profiles of cannabis-derived botanical drug substances (BDS) rich in cannabidivarin (CBDV) and containing cannabidiol (CBD) in acute in vivo seizure models and (ii) the binding of CBDV BDSs and their components at cannabinoid CB1 receptors.

CDBV BDSs exerted significant anticonvulsant effects… 

CONCLUSIONS AND IMPLICATIONS:

CBDV BDSs exerted significant anticonvulsant effects in three models of seizure that were not mediated by the CB1 cannabinoid receptor, and were of comparable efficacy to purified CBDV.

These findings strongly support the further clinical development of CBDV BDSs for treatment of epilepsy.”

http://www.ncbi.nlm.nih.gov/pubmed/23902406

“Cannabidivarin is anticonvulsant in mouse and rat… These results indicate that CBDV is an effective anticonvulsant in a broad range of seizure models.”  http://www.ncbi.nlm.nih.gov/pubmed/22970845

CB1 agonists, locally applied to the cortico-thalamic circuit of rats with genetic absence epilepsy, reduce epileptic manifestations.

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“Drugs that modulate the endocannabinoid system and endocannabinoids typically play an anticonvulsant role although some proconvulsant effects have been reported both in humans and animal models.

 This study aims to characterize the role of cannabinoids in specific areas of the cortico-thalamic network involved in oscillations that underlie seizures in a genetic animal model of absence epilepsy, the WAG/Rij rat.

These results, together with previous reports, support therapeutic potential for endocannabinoid system modulators in absence epilepsy and highlight that attenuated endocannabinergic function may contribute to the generation and maintenance of seizures. Furthermore, the entire cortico-thalamic network responds to cannabinoid treatment, indicating that in all areas considered, CB receptor activation inhibits the pathological synchronization that subserves absence seizures.

 In conclusion, our result might be useful for the identification of future drug therapies in absence epilepsy.”

http://www.ncbi.nlm.nih.gov/pubmed/23860329