[Essential fatty acids and lipid mediators. Endocannabinoids].

“Balance between omega-3 and omega-6 acids has a profound influence on all the body’s inflammatory responses and a raised level of PUFA omega-3 in tissue correlate with a reduced incidence of degenerative cardiovascular disease, some mental illnesses such as depression, and neuro-degenerative diseases such as Alzheimer’s.

Recent advances in the biochemistry and pharmacology of the endocannabinoid system…

will offer the development of novel therapeutic agents.”

http://www.ncbi.nlm.nih.gov/pubmed/22730630

Cannabinoid CB2 receptors and fatty acid amide hydrolase are selectively overexpressed in neuritic plaque-associated glia in Alzheimer’s disease brains.

.”We have studied the status of some of the components of the endocannabinoid system, fatty acid amide hydrolase and cannabinoid CB1 and CB2 receptors, in postmortem brains from patients with Alzheimer’s disease. Our results show that both fatty acid amide hydrolase and cannabinoid CB2 receptors are abundantly and selectively expressed in neuritic plaque-associated astrocytes and microglia, respectively, whereas the expression of CB1 receptors remains unchanged. In addition, the hydrolase activity seems to be elevated in the plaques and surrounding areas.

Thus, some elements of the endocannabinoid system may be postulated as possible modulators of the inflammatory response associated with this neurodegenerative process and as possible targets for new therapeutic approaches.

To our knowledge, this report is the first evidence for the presence of CB2 receptors in the human CNS. Furthermore, these receptors have recently been reported to play an important role in microglial migration. It is important to note that we detected CB2 receptors only in microglial cells, which is in agreement with the well known immunomodulatory effects of CB2 activation. Thus, many studies have shown that CB2 receptor activation leads to a myriad of changes in the production of inflammation-related substances, although with results that vary depending on the experimental model used and the concentration of cannabinoids used.

 In any case, the selective presence of CB2 receptors in microglial cells opens new perspectives on the role of CB2 receptors in the human CNS and suggests that the modulation of their activity may have therapeutic implications.”

http://www.jneurosci.org/content/23/35/11136.long

Activation of the CB(2) receptor system reverses amyloid-induced memory deficiency.

“Cannabinoid type 2 (CB(2)) agonists are neuroprotective and appear to play modulatory roles in neurodegenerative processes in Alzheimer’s disease. We have studied the effect of 1-((3-benzyl-3-methyl-2,3-dihydro-1-benzofuran-6-yl) carbonyl) piperidine (MDA7)-a novel selective CB(2) agonist that lacks psychoactivity-on ameliorating the neuroinflammatory process, synaptic dysfunction, and cognitive impairment 

 Our findings suggest that MDA7 is an innovative therapeutic approach for the treatment of Alzheimer’s disease.”

http://www.ncbi.nlm.nih.gov/pubmed/22795792

The activation of cannabinoid CB2 receptors stimulates in situ and in vitro beta-amyloid removal by human macrophages.

“The endocannabinoid system is a promising therapeutic target in a wide variety of diseases. However, the non-desirable psychotropic effects of natural and synthetic cannabinoids have largely counteracted their clinical usefulness. These effects are mostly mediated by cannabinoid receptors of the CB(1) type, that exhibit a wide distribution in neuronal elements of the CNS. Thus, the presence of other elements of this system in the CNS, such as CB(2) receptors, may open new possibilities for the development of cannabinoid-based therapies. These receptors are almost absent from the CNS in normal conditions but are up-regulated in glial cells under chronic neuroinflammatory stimuli, as has been described in Alzheimer’s disease. To understand the functional role of these receptors, we tested their role in the process of beta-amyloid removal, that is currently considered as one of the most promising experimental approaches for the treatment of this disease.

Our results show that a CB(2) agonist (JWH-015) is capable of inducing the removal of native beta-amyloid removal from human frozen tissue sections as well as of synthetic pathogenic peptide by a human macrophage cell line (THP-1). Remarkably, this effect was achieved at low doses and was specific for this type of cells, as U373MG astrocytoma cells did not respond to the treatment. The effect was CB(2)-mediated, at least partially, as the selective CB(2) antagonist SR144528 prevented the JWH-015-induced plaque removal in situ.

 These data corroborate the possible therapeutic interest of CB(2) cannabinoid specific chemicals in the treatment of Alzheimer’s disease.”

http://www.ncbi.nlm.nih.gov/pubmed/19505450

A molecular link between the active component of marijuana and Alzheimer’s disease pathology.

“A link between the endocannabinoid system and Alzheimer’s disease has been discovered which has provided a new therapeutic target for the treatment of patients suffering from Alzheimer’s disease. These studies have demonstrated the ability of cannabinoids to provide neuroprotection against β-amyloid peptide (Aβ) toxicity.

Here, we demonstrate that the active component of marijuana, Δ9-tetrahydrocannabinol (THC), competitively inhibits the enzyme acetylcholinesterase (AChE) as well as prevents AChE-induced amyloid β-peptide (Aβ) aggregation, the key pathological marker of Alzheimer’s disease. 

 Compared to currently approved drugs prescribed for the treatment of Alzheimer’s disease, THC is a considerably superior inhibitor of Aβ aggregation, and this study provides a previously unrecognized molecular mechanism through which cannabinoid molecules may directly impact the progression of this debilitating disease.

Since the characterization of the Cannabis sativa-produced cannabinoid, Δ9-tetrahydrocannabinol (THC), in the 1960’s,1 this natural product has been widely explored as an anti-emetic, anti-convulsive, anti-inflammatory, and analgesic.”

Read more: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2562334/

 

The endocannabinoid system in targeting inflammatory neurodegenerative diseases.

“The classical divide between degenerative and inflammatory disorders of the CNS is vanishing as accumulating evidence shows that inflammatory processes are important in the pathophysiology of primarily degenerative disorders, and neurodegeneration complicates primarily inflammatory diseases of the brain and spinal cord. Here, we review the contribution of degenerative and inflammatory processes to CNS disorders such as Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, multiple sclerosis and HIV-associated dementia.

An early combination of neuroprotective and anti-inflammatory approaches to these disorders seems particularly desirable because isolated treatment of one pathological process might worsen another.

We also discuss the apparently unique opportunity to modify neurodegeneration and neuroinflammation simultaneously by pharmacological manipulation of the endocannabinoid system in the CNS and in peripheral immune cells. Current knowledge of this system and its involvement in the above CNS disorders are also reviewed.”

http://www.ncbi.nlm.nih.gov/pubmed/17350694

Endocannabinoid system: emerging role from neurodevelopment to neurodegeneration.

“The endocannabinoid system, including endogenous ligands (‘endocannabinoids’ ECs), their receptors, synthesizing and degrading enzymes, as well as transporter molecules, has been detected from the earliest stages of embryonic development and throughout pre- and postnatal development. ECs are bioactive lipids, which comprise amides, esters and ethers of long chain polyunsaturated fatty acids. Anandamide (N-arachidonoylethanolamine; AEA) and 2-arachidonoylglycerol (2-AG) are the best studied ECs, and act as agonists of cannabinoid receptors.

Thus, AEA and 2-AG mimic several pharmacological effects of the exogenous cannabinoid delta9-tetrahydrocannabinol (Delta(9)-THC), the psychoactive principle of cannabis sativa preparations like hashish and marijuana. Recently, however, several lines of evidence have suggested that the EC system may play an important role in early neuronal development as well as a widespread role in neurodegeneration disorders. Many of the effects of cannabinoids and ECs are mediated by two G protein-coupled receptors (GPCRs), CB1 and CB2, although additional receptors may be implicated. Both CB1 and CB2 couple primarily to inhibitory G proteins and are subject to the same pharmacological influences as other GPCRs. This new system is briefly presented in this review, in order to put in a better perspective the role of the EC pathway from neurodevelopment to neurodegenerative disorders, like Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and multiple sclerosis.

In addition, the potential exploitation of antagonists of CB1 receptors, or of inhibitors of EC metabolism, as next-generation therapeutics is discussed.”

http://www.ncbi.nlm.nih.gov/pubmed/19356123

Cannabinoids and neurodegenerative diseases.

“Although significant advances have taken place in recent years on our understanding of the molecular mechanisms of different neurodegenerative diseases, its translation into effective therapeutic treatments has not been as successful as could be expected. There is still a dramatic lack of curative treatments for the most frequent disorders and only symptomatic relief for many others. Under this perspective, the search for novel therapeutic approaches is demanding and significant attention and efforts have been directed to studying additional neurotransmission systems including the endocannabinoid system (ECS).

The neuroprotective properties of exogenous as well as endogenous cannabinoids have been known for years and the underlying molecular mechanisms have been recently unveiled. As discussed later, antioxidative, antiglutamatergic and antiinflammatory effects are now recognized as derived from cannabinoid action and are known to be of common interest for many neurodegenerative processes.

 Thus, these characteristics make cannabinoids attractive candidates for the development of novel therapeutic strategies.

 The present review will focus on the existing data regarding the possible usefulness of cannabinoid agents for the treatment of relevant neurological pathologies for our society such as Alzheimer’s disease, multiple sclerosis, Huntington’s disease and amyotrophic lateral sclerosis.”

http://www.ncbi.nlm.nih.gov/pubmed/19839933

Cannabinoid CB1 receptor stimulation affords neuroprotection in MPTP-induced neurotoxicity by attenuating S100B up-regulation in vitro.

 “…the involvement of the endocannabinoid system was investigated by using selective inhibitors of endocannabinoid inactivation (cellular re-uptake or enzymatic hydrolysis) and selective cannabinoid CB1 and CB2 receptor antagonists and by silencing the CB1 receptor…

 Our data suggest that selective activation of CB1 receptors by either exogenous or endogenous cannabinoids might afford neuroprotection…”

http://www.ncbi.nlm.nih.gov/pubmed/17639288

Distribution patterns of cannabinoid CB1 receptors in the hippocampus of APPswe/PS1ΔE9 double transgenic mice.

Abstract

“Cannabinoids have neuroprotective effects that are exerted primarily through cannabinoid CB1 receptors in the brain. This study characterized CB1 receptor distribution in the double transgenic (dtg) APP(swe)/PS1(ΔE9) mouse model for Alzheimer’s disease. Immunohistochemical labeling of CB1 protein in non-transgenic mice revealed that CB1 was highly expressed in the hippocampus, with the greatest density of CB1 protein observed in the combined hippocampal subregions CA2 and CA3 (CA2/3). CB1 immunoreactivity in the CA1 and CA2/3 hippocampal regions was significantly decreased in the dtg APP(swe)/PS1(ΔE9) mice compared to non-transgenic littermates. Reduced CB1 expression in dtg APP(swe)/PS1(ΔE9) mice was associated with astroglial proliferation and elevated expression of the cytokines inducible nitric oxide synthase and tumor necrosis factor alpha. This finding suggests an anti-inflammatory effect of cannabinoids that is mediated by CB1 receptor, particularly in the CA2/3 region of the hippocampus. Furthermore, the study suggests a decreased CB1 receptor expression may result in diminished anti-inflammatory processes, exacerbating the neuropathology associated with Alzheimer’s disease.”

http://www.ncbi.nlm.nih.gov/pubmed/21192920