Endogenous and Synthetic Cannabinoids as Therapeutics in Retinal Disease.

“The functional significance of cannabinoids in ocular physiology and disease has been reported some decades ago.

In the early 1970s, subjects who smoked Cannabis sativa developed lower intraocular pressure (IOP). This led to the isolation of phytocannabinoids from this plant and the study of their therapeutic effects in glaucoma.

The main treatment of this disease to date involves the administration of drugs mediating either the decrease of aqueous humour synthesis or the increase of its outflow and thus reduces IOP. However, the reduction of IOP is not sufficient to prevent visual field loss.

Retinal diseases, such as glaucoma and diabetic retinopathy, have been defined as neurodegenerative diseases and characterized by ischemia-induced excitotoxicity and loss of retinal neurons. Therefore, new therapeutic strategies must be applied in order to target retinal cell death, reduction of visual acuity, and blindness.

The aim of the present review is to address the neuroprotective and therapeutic potential of cannabinoids in retinal disease.”

http://www.ncbi.nlm.nih.gov/pubmed/26881135

Therapeutic Potential of Cannabinoids in Psychosis.

“Over recent years, the interest in the endocannabinoid system (ECS) as a new target for the treatment of schizophrenia has evolved.

The ECS represents one of the most relevant neurotransmitter systems in the brain and mainly fulfills a homeostatic role in terms of neurotransmission but also with respect to inflammatory processes.

Two main approaches to the modulation of endocannabinoid functioning have been chosen so far. First, the selective blockade or inverse agonism of the type 1 cannabinoid receptor has been tested for the improvement of acute psychotic symptoms, as well as for the improvement of cognitive functions in schizophrenia.

Second, the modulation of endocannabinoid levels by use of the phytocannabinoid cannabidiol and selective fatty acid amide hydrolase inhibitors has been proposed, and the antipsychotic properties of cannabidiol are currently being investigated in humans.

Unfortunately, for most of these trials that have focused on psychopathological and cognitive effects of cannabidiol, no published data are available. However, there is first evidence that cannabidiol may ameliorate psychotic symptoms with a superior side-effect profile compared with established antipsychotics.

In conclusion, several clinical trials targeting the ECS in acute schizophrenia have either been completed or are underway. Although publicly available results are currently limited, preliminary data indicate that selected compounds modulating the ECS may be effective in acute schizophrenia.

Nevertheless, so far, sample sizes of patients investigated are not sufficient to come to a final judgment, and no maintenance studies are available to ensure long-term efficacy and safety.”

http://www.ncbi.nlm.nih.gov/pubmed/26852073

http://www.thctotalhealthcare.com/category/schizophrenia/

Cannabinoids for pediatric epilepsy? Up in smoke or real science?

“Public interest in the use of “medical marijuana” for the treatment of childhood epilepsy has burgeoned in the last few years. This has occurred in parallel with a growing interest in “medical marijuana” in general. Physicians and pediatricians must balance their patients’ desire for immediate access to these products with the tenets of evidence-based medicine. This review discusses the biochemistry of cannabis products (the phytocannabinoids) setting this in the context of the endogenous endocannabinoid system. The differing and potentially modulating effects of delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are reviewed. The evidence-base supporting or not the use of cannabis products for the treatment of neurological disease and specifically epilepsy is explored. The potential for adverse effects and particularly of neurotoxicity is addressed. Finally, public health and sociocultural implications are touched upon. Specific recommendations for interested physicians are provided including advocacy for patients and for a change in the “scheduling” of cannabis in order to better foster much-needed high-quality scientific research in this important area.”

http://www.ncbi.nlm.nih.gov/pubmed/26835389

Small Molecules from Nature Targeting G-Protein Coupled Cannabinoid Receptors: Potential Leads for Drug Discovery and Development.

“The cannabinoid molecules are derived from Cannabis sativa plant which acts on the cannabinoid receptors types 1 and 2 (CB1 and CB2) which have been explored as potential therapeutic targets for drug discovery and development.

Currently, there are numerous cannabinoid based synthetic drugs used in clinical practice like the popular ones such as nabilone, dronabinol, and Δ9-tetrahydrocannabinol mediates its action through CB1/CB2receptors.

In recent years, many phytocannabinoids have been isolated from plants other than Cannabis. Several studies have shown that these phytocannabinoids show affinity, potency, selectivity, and efficacy towards cannabinoid receptors and inhibit endocannabinoid metabolizing enzymes, thus reducing hyperactivity of endocannabinoid systems.

Also, these naturally derived molecules possess the least adverse effects opposed to the synthetically derived cannabinoids. Therefore, the plant based cannabinoid molecules proved to be promising and emerging therapeutic alternative.

The present review provides an overview of therapeutic potential of ligands and plants modulating cannabinoid receptors that may be of interest to pharmaceutical industry in search of new and safer drug discovery and development for future therapeutics.”

A Sativex(®) -like combination of phytocannabinoids as a disease-modifying therapy in a viral model of multiple sclerosis.

“Sativex(®) is an oromucosal spray, containing equivalent amounts of Δ(9) -tetrahydrocannabinol (Δ(9) -THC) and cannabidiol (CBD)-botanical drug substance (BDS), which has been approved for the treatment of spasticity and pain associated to multiple sclerosis (MS).

In this study, we investigated whether Sativex may also serve as a disease-modifying agent in the Theiler’s murine encephalomyelitis virus-induced demyelinating disease model of MS.

The data support the therapeutic potential of Sativex to slow MS progression and its relevance in CNS repair.”

http://www.ncbi.nlm.nih.gov/pubmed/25857324

The disease-modifying effects of a Sativex-like combination of phytocannabinoids in mice with experimental autoimmune encephalomyelitis are preferentially due to Δ9-tetrahydrocannabinol acting through CB1 receptors.

“Sativex®, an equimolecular combination of Δ9-tetrahydrocannabinol-botanical drug substance (Δ9-THC-BDS) and cannabidiol-botanical drug substance (CBD-BDS), is a licensed medicine that may be prescribed for alleviating specific symptoms of multiple sclerosis (MS) such as spasticity and pain.

However, further evidence suggest that it could be also active as disease-modifying therapy given the immunomodulatory, anti-inflammatory and cytoprotective properties of their two major components.

In this study, we investigated this potential in the experimental autoimmune encephalitis (EAE) model of MS in mice.

We compared the effect of a Sativex-like combination of Δ9-THC-BDS (10mg/kg) and CBD-BDS (10mg/kg) with Δ9-THC-BDS (20mg/kg) or CBD-BDS (20mg/kg) administered separately by intraperitoneal administration to EAE mice.

Treatments were initiated at the time that symptoms appear and continued up to the first relapse of the disease.

The results show that the treatment with a Sativex-like combination significantly improved the neurological deficits typical of EAE mice, in parallel with a reduction in the number and extent of cell aggregates present in the spinal cord which derived from cell infiltration to the CNS.

These effects were completely reproduced by the treatment with Δ9-THC-BDS alone, but not by CBD-BDS alone which only delayed the onset of the disease without improving disease progression and reducing the cell infiltrates in the spinal cord.

Next, we investigated the potential targets involved in the effects of Δ9-THC-BDS by selectively blocking CB1 or PPAR-γ receptors, and we found a complete reversion of neurological benefits and the reduction in cell aggregates only with rimonabant, a selective CB1 receptor antagonist.

Collectively, our data support the therapeutic potential of Sativex as a phytocannabinoid formulation capable of attenuating EAE progression, and that the active compound was Δ9-THC-BDS acting through CB1 receptors.”

Anti-inflammatory effects of the cannabidiol derivative dimethylheptyl-cannabidiol – studies in BV-2 microglia and encephalitogenic T cells.

“Dimethylheptyl-cannabidiol (DMH-CBD), a non-psychoactive, synthetic derivative of the phytocannabinoid cannabidiol (CBD), has been reported to be anti-inflammatory in RAW macrophages.

Here, we evaluated the effects of DMH-CBD at the transcriptional level in BV-2 microglial cells as well as on the proliferation of encephalitogenic T cells…

The results show that DMH-CBD has similar anti-inflammatory properties to those of CBD.

DMH-CBD downregulates the expression of inflammatory cytokines and protects the microglial cells by inducing an adaptive cellular response against inflammatory stimuli and oxidative injury.”

http://www.ncbi.nlm.nih.gov/pubmed/26540221

Polypharmacology Shakes Hands with Complex Aetiopathology.

“Chronic diseases are due to deviations of fundamental physiological systems, with different pathologies being characterised by similar malfunctioning biological networks.

The ensuing compensatory mechanisms may weaken the body’s dynamic ability to respond to further insults and reduce the efficacy of conventional single target treatments.

The multitarget, systemic, and prohomeostatic actions emerging for plant cannabinoids exemplify what might be needed for future medicines.

Indeed, two combined cannabis extracts were approved as a single medicine (Sativex®), while pure cannabidiol, a multitarget cannabinoid, is emerging as a treatment for paediatric drug-resistant epilepsy.

Using emerging cannabinoid medicines as an example, we revisit the concept of polypharmacology and describe a new empirical model, the ‘therapeutic handshake’, to predict efficacy/safety of compound combinations of either natural or synthetic origin.”

http://www.ncbi.nlm.nih.gov/pubmed/26434643

A comparison of cannabidiolic acid with other treatments for anticipatory nausea using a rat model of contextually elicited conditioned gaping.

“The effectiveness of cannabidiolic acid (CBDA) was compared with other potential treatments for anticipatory nausea (AN), using a rat model of contextually elicited conditioned gaping reactions.

The potential of ondansetron (OND), Δ(9)-tetrahydrocannabinol (THC), chlordiazepoxide (CDP), CBDA, and co-administration of CBDA and tetrahydrocannabinolic acid (THCA) to reduce AN and modify locomotor activity was evaluated…

CBDA has therapeutic potential as a highly potent and selective treatment for AN without psychoactive or locomotor effects.”

http://www.ncbi.nlm.nih.gov/pubmed/24595502

The phytocannabinoid, Δ⁹-tetrahydrocannabivarin, can act through 5-HT₁A receptors to produce antipsychotic effects.

“This study aimed to address the questions of whether Δ(9)-tetrahydrocannabivarin (THCV) can (i) enhance activation of 5-HT1 A receptors in vitro and (ii) induce any apparent 5-HT₁A receptor-mediated antipsychotic effects in vivo…

Our findings suggest that THCV can enhance 5-HT₁A receptor activation, and that some of its apparent antipsychotic effects may depend on this enhancement.

We conclude that THCV has therapeutic potential for ameliorating some of the negative, cognitive and positive symptoms of schizophrenia.”

http://www.ncbi.nlm.nih.gov/pubmed/25363799