Medical marijuana programs – Why might they matter for public health and why should we better understand their impacts?

“Although cannabis is an illegal drug, ‘medical marijuana programs’ (MMPs) have proliferated (e.g., in Canada and several US states), allowing for legal cannabis use for therapeutic purposes.

While both health risks and potential therapeutic  for cannabis use have been documented, potential public health impacts of MMPs – also vis-à-vis other psychoactive substance use – remain under-explored.

We briefly reviewed the emerging evidence on MMP participants’ health status, and specifically other psychoactive substance use behaviors and outcomes.

MMP participants report improvements in overall health status, and specifically reductions in levels of risky alcohol, prescription drug and – to some extent – tobacco or other illicit drug use…”

http://www.ncbi.nlm.nih.gov/pubmed/26844050

Medicinal cannabis.

“A number of therapeutic uses of cannabis and its derivatives have been postulated from preclinical investigations.

Possible clinical indications include spasticity and pain in multiple sclerosis, cancer-associated nausea and vomiting, cancer pain and HIV neuropathy.

Controversies lie in how to produce, supply and administer cannabinoid products.

Introduction of cannabinoids therapeutically should be supported by a regulatory and educational framework that minimises the risk of harm to patients and the community.

The Regulator of Medicinal Cannabis Bill 2014 is under consideration in Australia to address this.

Nabiximols is the only cannabinoid on the Australian Register of Therapeutic Goods at present, although cannabidiol has been recommended for inclusion in Schedule 4.”

http://www.ncbi.nlm.nih.gov/pubmed/26843715

“There is some evidence of therapeutic benefit for cannabis products in defined patient populations.” http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4674028/

A systematic review of plant-derived natural compounds for anxiety disorders.

“Anxiety disorders are the most common mental illnesses affecting human beings. They range from panic to generalized anxiety disorders upsetting the well-being and psychosocial performance of patients. Several conventional anxiolytic drugs are being used which in turn result in several adverse effects. Therefore, studies to find suitable safe medicines from natural sources are being conducted by researchers.

The aim of the present study is to comprehensively review phytochemical compounds with well-established anxiolytic activities and their structure-activity relationships as well as neuropsychopharmacological aspects. Results showed that phytochemicals like; alkaloids, flavonoids, phenolic acids, lignans, cinnamates, terpenes and saponins possess anxiolytic effects in a wide range of animal models of anxiety.

The involved mechanisms include interaction with γ-aminobutyric acid (GABA)A receptors at benzodiazepine (BZD) and non-BZD sites with various affinity to different subunits, serotonergic 5-hydrodytryptamine (5-HT)1A and 5-HT2A/C receptors, noradrenergic and dopaminergic systems, glycine and glutamate receptors, and κ-opioid receptor as well as cannabinoid (CB)1 and CB2 receptors.

Phytochemicals also modulate the hypothalamo-pituitary-adrenal (HPA) axis, the levels of pro-inflammatory cytokines like interleukin (IL)-2, IL-6, IL-1β and tumor necrosis factor (TNF)-α, and improve brain derived neurotrophic factor (BDNF) levels. Transient receptor potential cation channel subfamily V (TRPV)3, nitric oxide cyclic guanosine monophosphate (NO-cGMP) pathway and monoamine oxidase enzymes are other targets of phytochemicals with anxiolytic activity.

Taking together, these phytochemicals may be considered as supplements to conventional anxiolytic therapies in order to improve efficacy and reduce adverse effects.

Further preclinical and clinical studies are still needed in order to recognize the structure-activity relationships, metabolism, absorption, and neuropsychopharmacological mechanisms of plant-derived natural agents.”

http://www.ncbi.nlm.nih.gov/pubmed/26845556

Cannabinoids for the Treatment of Schizophrenia: An Overview.

“Δ9-tetrahydrocannabinol and its analogues are found to have particular application in psychiatry because of their antipsychotic properties suggesting a therapeutic use as neuroleptic agents in limiting psychotic diseases.

These treatments should not only aim to alleviate specific symptoms but also attempt to delay/arrest disease progression.

In the present review, we reported recent studies supporting the view that the cannabinoid signalling system is a key modulatory element in the activity of the striatum and temporal cortex that has been traditionally associated with psychosis and schizophrenia.

This idea is supported by different anatomical, electrophysiological, pharmacological and biochemical data.

Furthermore, these studies indicate that the cannabinoid system is impaired in different psychotic disorders, supporting the idea of developing novel pharmacotherapies with compounds that selectively target specific elements of the cannabinoid system.”

http://www.ncbi.nlm.nih.gov/pubmed/26845552

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

The Cannabinoid CB1/CB2 Agonist WIN55212.2 Promotes Oligodendrocyte Differentiation In Vitro and Neuroprotection During the Cuprizone-Induced Central Nervous System Demyelination.

“Different types of insults to the CNS lead to axon demyelination. Remyelination occurs when the CNS attempts to recover from myelin loss and requires the activation of oligodendrocyte precursor cells.

With the rationale that CB1 receptor is expressed in oligodendrocytes and marijuana consumption alters CNS myelination, we study the effects of the cannabinoid agonist WIN55212.2 in (1) an in vitro model of oligodendrocyte differentiation and (2) the cuprizone model for demyelination.

The cannabinoid agonist WIN55212.2 promotes oligodendrocyte differentiation in vitro.

Moreover, 0.5 mg/kg of the drug confers neuroprotection during cuprizone-induced demyelination, while 1 mg/kg aggravates the demyelination process.”

http://www.ncbi.nlm.nih.gov/pubmed/26842941

JWH-133, a Selective Cannabinoid CB2 Receptor Agonist, Exerts Toxic Effects on Neuroblastoma SH-SY5Y Cells.

“Endocannabinoid system plays an important role in the regulation of diverse physiological functions.

Although cannabinoid type 2 receptors (CB2) are involved in the modulation of immune system in peripheral tissues, recent findings demonstrated that they are also expressed in the central nervous system and could constitute a new target for the treatment of neurodegenerative disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/26842917

Simultaneous Activation of Induced Heterodimerization between CXCR4 Chemokine Receptor and Cannabinoid Receptor 2 (CB2) Reveal a Mechanism for Regulation of Tumor Progression.

“The G-protein-coupled chemokine receptor, CXCR4, generates signals that lead to cell migration, cell proliferation, and other survival mechanisms which result in the metastatic spread of primary tumor cells to distal organs.

Numerous studies have demonstrated that CXCR4 can form homodimers, or can heterodimerize with other GPCRs to form receptor complexes that can amplify or decrease the signaling capacity of each individual receptor.

Using biophysical and biochemical approaches, we found that CXCR4 can form an induced heterodimer with cannabinoid receptor 2 (CB2) in human breast and prostate cancer cells.

Simultaneous, agonist-dependent activation of CXCR4 and CB2 resulted in reduced CXCR4-mediated expression of phosphorylated ERK1/2, and ultimately, reduced cancer cell functions such as calcium mobilization and cellular chemotaxis.

Given that treatment with cannabinoids has been shown to reduce invasiveness of cancer cells, as well as CXCR4-mediated migration of immune cells, it is therefore plausible that CXCR4 signaling can be silenced through a physical heterodimeric association with CB2, thereby inhibiting subsequent functions of CXCR4.

Taken together, the data illustrates a mechanism by which the cannabinoid system can negatively modulate CXCR4 receptor function, and perhaps, tumor progression.”

http://www.ncbi.nlm.nih.gov/pubmed/26841863

Cannabinoids for treatment of glaucoma.

“The purpose of this article is to review the current status of cannabis in the treatment of glaucoma, including the greater availability of marijuana in the USA.

The pharmacology of marijuana and its effect on intraocular pressure has not changed since the research in the 1970s and 1980s.

Marijuana is an effective ocular hypotensive agent.

However, cardiovascular and neurological effects are observed at the same dose, and may theoretically reduce the beneficial effect of lowering intraocular pressure by reducing ocular blood flow. The clinician must be cognizant of this potential in diagnosis, prognosis, and therapy.”

http://www.ncbi.nlm.nih.gov/pubmed/26840343

Expression and Function of the Endocannabinoid System in the Retina and the Visual Brain.

“Endocannabinoids are important retrograde modulators of synaptic transmission throughout the nervous system.

Cannabinoid receptors are seven transmembrane G-protein coupled receptors favoring Gi/o protein. They are known to play an important role in various processes, including metabolic regulation, craving, pain, anxiety, and immune function.

In the last decade, there has been a growing interest for endocannabinoids in the retina and their role in visual processing.

The purpose of this review is to characterize the expression and physiological functions of the endocannabinoid system in the visual system, from the retina to the primary visual cortex, with a main interest regarding the retina, which is the best-described area in this system so far.

It will show that the endocannabinoid system is widely present in the retina, mostly in the through pathway where it can modulate neurotransmitter release and ion channel activity, although some evidence also indicates possible mechanisms via amacrine, horizontal, and Müller cells.

The presence of multiple endocannabinoid ligands, synthesizing and catabolizing enzymes, and receptors highlights various pharmacological targets for novel therapeutic application to retinal diseases.”

http://www.ncbi.nlm.nih.gov/pubmed/26839718

Metabolomics of Δ9-tetrahydrocannabinol: implications in toxicity.

“Cannabis sativa is the most commonly used recreational drug, Δ9-tetrahydrocannabinol (Δ9-THC) being the main addictive compound.

Biotransformation of cannabinoids is an important field of xenobiochemistry and toxicology and the study of the metabolism can lead to the discovery of new compounds, unknown metabolites with unique structures and new therapeutic effects.

The pharmacokinetics of Δ9-THC is dependent on multiple factors such as physical/chemical form, route of administration, genetics, and concurrent consumption of alcohol.

This review aims to discuss metabolomics of Δ9-THC, namely by presenting all known metabolites of Δ9-THC described both in vitro and in vivo, and their roles in the Δ9-THC-mediated toxic effects.

Since medicinal use is increasing, metabolomics of Δ9-THC will also be discussed in order to uncover potential active metabolites that can be made available for this purpose.”

http://www.ncbi.nlm.nih.gov/pubmed/26828228