Cannabidiol and other cannabinoids reduce microglial activation in vitro and in vivo: relevance to Alzheimer’s disease.

“Microglial activation is an invariant feature of Alzheimer’s disease (AD). It is noteworthy that cannabinoids are neuroprotective by preventing β-amyloid (Aβ)-induced microglial activation both in vitro and in vivo… the phytocannabinoid cannabidiol (CBD) has shown anti-inflammatory properties in different paradigms…

Cannabinoids, whether plant-derived, synthetic, or endocannabinoids, exert their functions through activation of cannabinoid receptors, two of which have been well characterized to date: CB1 and CB2. Cannabinoids are neuroprotective against excitotoxicity and acute brain damage, both in vitro and in vivo. Several mechanisms account for the neuroprotection afforded by this type of drug such as blockade of excitotoxicity, reduction of calcium influx, antioxidant properties of the compounds, or enhanced trophic factor support. A decrease in proinflammatory mediators brought about by cannabinoids may be also involved in their neuroprotection… Cannabidiol (CBD), the major plant-derived nonpsychotropic constituent of marijuana, is of potential therapeutic interest in different disease conditions (e.g., inflammation)…

…this kind of drug with neuroprotective and anti-inflammatory effects may be of interest in the prevention of AD inflammation, in particular CB2-selective agonists, which are devoid of psychoactive effects…

Cannabidiol and other cannabinoids reduce microglial activation in vitro and in vivo…

CBD is able to modulate microglial cell function in vitro and induce beneficial effects in an in vivo model of AD.

Given that CBD lacks psychoactivity, it may represent a novel therapeutic approach for this neurological disease.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3102548/

Effects of dronabinol on anorexia and disturbed behavior in patients with Alzheimer’s disease.

“A placebo-controlled crossover design to investigate effects of dronabinol (THC) in patients with a diagnosis of probable Alzhemer’s disease who were refusing food. 

These results indicate that dronabinol is a promising novel therapeutic agent which may be useful not only for treatment of anorexia but also to improve disturbed behavior in patients with Alzheimer’s disease.”

http://www.ncbi.nlm.nih.gov/pubmed/9309469

Regulation of cannabinoid CB1 receptors in the central nervous system by chronic cannabinoids.

“The potential therapeutic benefits of certain cannabinoid-mediated effects, as well as the use of marijuana for its psychoactive properties, has raised interest in understanding the cellular adaptations produced by chronic administration of this class of drugs.”

http://www.ncbi.nlm.nih.gov/pubmed/14977366

Intact cannabinoid CB1 receptors in the Alzheimer’s disease cortex.

“The cannabinoid CB1 receptor has gained much attention as a potential pharmacotherapeutic target in various neurodegenerative diseases including Alzheimer’s disease (AD). Our study suggests that CB1 receptors are intact in AD and may play a role in preserving cognitive function.

 Therefore, CB1 receptors should be further assessed as a potential therapeutic target in AD.”

http://www.ncbi.nlm.nih.gov/pubmed/21034788

Cannabinoid system in neurodegeneration: new perspectives in Alzheimer’s disease.

“Alzheimer’s disease is a chronic and progressive neurodegenerative disorder. The presence of functional cannabinoid CB2 receptors in central nervous system (CNS) has provoked that this receptor and its agonist ligands are now considered as promising pharmacological targets for neurological diseases. Herein, we review the evidences supporting the potential role of the ECS as a therapeutic target, focused on CB2 receptor and its ligands, for the treatment of Alzheimer’s disease.”

http://www.ncbi.nlm.nih.gov/pubmed/19456285

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

Alzheimer’s disease and inflammation: a review of cellular and therapeutic mechanisms.

“1. Of the neurodegenerative diseases that cause dementia, Alzheimer’s disease (AD) is the most common. Three major pathologies characterize the disease: senile plaques, neurofibrillary tangles and inflammation. We review the literature on events contributing to the inflammation and the treatments thought to target this pathology. 2. The senile plaques of AD consist primarily of complexes of the beta-amyloid protein. This protein is central to the pathogenesis of the disease. 3. Inflammatory microglia are consistently associated with senile plaques in AD, although the classic inflammatory response (immunoglobulin and leucocyte infiltration) is absent. beta-Amyloid fragments appear to mediate such inflammatory mechanisms by activating the complement pathway in a similar fashion to immunoglobulin. 4. Epidemiological studies have identified a reduced risk of AD in patients with arthritis and in leprosy patients treated with anti-inflammatory drugs. Longitudinal studies have shown that the consumption of anti-inflammatory medications reduces the risk of AD only in younger patients (< 75 years). 5. There is a considerable body of in vitro evidence indicating that the inflammatory response of microglial cells is reduced by non-steroidal anti-inflammatory drugs (NSAID). However, no published data are available concerning the effects of these medications on brain pathology in AD. 6. Cyclo-oxygenase 2 enzyme is constitutively expressed in neurons and is up-regulated in degenerative brain regions in AD. Non-steroidal anti-inflammatory drugs may reduce this expression. 7. Platelets are a source of beta-amyloid and increased platelet activation and increased circulating beta-amyloid have been identified in AD. Anti-platelet medication (including NSAID) would prevent such activation and its potentially harmful consequences. 8. Increased levels of luminal beta-amyloid permeabilizes the blood-brain barrier (BBB) and increases vasoconstriction of arterial vessels, paralleling the alterations observed with infection and inflammation. Cerebral amyloidosis is highly prevalent in AD, compromising the BBB and vasoactivity.

Anti-inflammatory medications may alleviate these problems.”

http://www.ncbi.nlm.nih.gov/pubmed/10696521

Nonpsychoactive Cannabidiol Prevents Prion Accumulation and Protects Neurons against Prion Toxicity

“Creutzfeldt–Jakob disease (CJD) in humans belongs to a group of fatal neurodegenerative disorders called transmissible spongiform encephalopathies (TSEs) or prion diseases. No therapeutic treatments against TSEs are currently available. The urgent need to find effective anti-prion therapies has been strengthened by the emergence of variant CJD (vCJD) caused by contaminated beef consumption …

Our results suggest that CBD may protect neurons against the multiple molecular and cellular factors involved in the different steps of the neurodegenerative process, which takes place during prion infection. When combined with its ability to target the brain and its lack of toxic side effects, CBD may represent a promising new anti-prion drug.

Overall, CBD is a promising therapeutic drug against the TSEs because it combines several crucial characteristics. It has a low toxicity and lack of psychotropic side effects as well as in vivo neuroprotective, anti-inflammatory, and anti-PrPres properties. Because CBD easily crosses the BBB, it also has the potential to be effective after prion infection has reached the CNS. Finally, prolonged treatments with CBD do not induce tolerance, a phenomenon frequently observed with THC. Additional investigations should be performed to define the optimal dose, route, frequency, and duration of the in vivo CBD treatment necessary to prevent TSE infection…”

http://www.jneurosci.org/content/27/36/9537.full

Cannabidiol inhibits inducible nitric oxide synthase protein expression and nitric oxide production in beta-amyloid stimulated PC12 neurons through p38 MAP kinase and NF-kappaB involvement.

“In view of the pro-inflammatory scenario observed in Alzheimer’s disease, in the recent years anti-inflammatory drugs have been proposed as potential therapeutic agents. We have previously shown that cannabidiol, the main non-psychotropic component from Cannabis sativa, possess a variegate combination of anti-oxidant and anti-apoptotic effects that protect PC12 cells from Abeta toxicity. In parallel, cannabidiol has been described to have anti-inflammatory properties in acute models of inflammation …

The here reported data increases our knowledge about the possible neuroprotective mechanism of cannabidiol, highlighting the importance of this compound to inhibit beta-amyloid induced neurodegeneration, in view of its low toxicity in humans.”

http://www.ncbi.nlm.nih.gov/pubmed/16490313

Effects of cannabinoids on the immune system and central nervous system: therapeutic implications.

“Cannabinoids possess immunomodulatory activity, are neuroprotective in vivo and in vitro and can modify the production of inflammatory mediators… Cannabinoid-induced immunosuppression may have implications for the treatment of neurological disorders that are associated with excess immunological activity, such as multiple sclerosis and Alzheimer’s disease. There is anecdotal evidence that cannabis use improves the symptoms of multiple sclerosis, and studies with animal models are beginning to provide evidence for the mechanism of such effects. The development of nonpsychotropic cannabinoid analogues and modulators of the metabolism of endogenous cannabinoid ligands may lead to novel approaches to the treatment of neurodegenerative disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/18031185