GPR3 and GPR6, novel molecular targets for cannabidiol.

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“GPR3 and GPR6 are members of a family of constitutively active, Gs protein-coupled receptors. Previously, it has been reported that GPR3 is involved in Alzheimer’s disease whereas GPR6 plays potential roles in Parkinson’s disease.

GPR3 and GPR6 are considered orphan receptors because there are no confirmed endogenous agonists for them. However, GPR3 and GPR6 are phylogenetically related to the cannabinoid receptors.

In this study, the activities of endocannabinoids and phytocannabinoids were tested on GPR3 and GPR6 using a β-arrestin2 recruitment assay. Among the variety of cannabinoids tested, cannabidiol (CBD), the major non-psychoactive component of marijuana, significantly reduced β-arrestin2 recruitment to both GPR3 and GPR6. In addition, the inhibitory effects of CBD on β-arrestin2 recruitment were concentration-dependent for both GPR3 and GPR6, with a higher potency for GPR6.

These data show that CBD acts as an inverse agonist at both GPR3 and GPR6 receptors. These results demonstrate for the first time that both GPR3 and GPR6 are novel molecular targets for CBD.

Our discovery that CBD acts as a novel inverse agonist on both GPR3 and GPR6 indicates that some of the potential therapeutic effects of CBD (e.g. treatment of Alzheimer’s disease and Parkinson’s disease) may be mediated through these important receptors.”

https://www.ncbi.nlm.nih.gov/pubmed/28571738

http://www.sciencedirect.com/science/article/pii/S0006291X17310744

Activation of CB2 receptor system restores cognitive capacity and hippocampal Sox2 expression in a transgenic mouse model of Alzheimer’s disease.

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“Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by neuroinflammation, extensive deposits of amyloid-β aggregates, and loss of memory and cognitive abilities. The brains of patients with AD show increased expression of cannabinoid receptor type 2 (CB2) receptors and glial markers. CB2 receptors act as a negative feedback regulator; when activated by a CB2agonist, they can help limit the extent of the neuroinflammatory response and the subsequent development of neuronal damage in the central nervous system. In a double transgenic APP/PS1 mice model of AD, we evaluated the effect of MDA7, a CB2 agonist, on several neuropathological conditions of AD including amyloid deposition, inflammatory reaction, Sox2 (sex-determining region Y-box 2) expression, and spatial memory. Activation of microglia CB2 receptors by MDA7 suppressed neuroinflammation, demonstrated by decreased immunosignal of Iba1 in the hippocampal CA1 and dentate gyrus (DG) areas, promoted clearance of amyloid plaques in the DG area, restored Sox2 expression, and promoted recovery of the neuronal synaptic plasticity in hippocampal CA1. In addition, treatment with MDA7 improved the behavioral performance in the Morris water maze in APP/PS1mice. Collectively, these findings suggest that MDA7 has a potential therapeutic effect in the setting of AD.”

https://www.ncbi.nlm.nih.gov/pubmed/28551012

http://www.sciencedirect.com/science/article/pii/S0014299917303758

Neuroprotection in oxidative stress-related neurodegenerative diseases: role of endocannabinoid system modulation.

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“Redox imbalance may lead to overproduction of reactive oxygen and nitrogen species (ROS/RNS) and subsequent oxidative tissue damage which is a critical event in the course of neurodegenerative diseases. It is still not fully elucidated, however, whether oxidative stress is the primary trigger or a consequence in process of neurodegeneration.

Recent Advances: Increasing evidence suggests that oxidative stress is involved in the propagation of neuronal injury and consequent inflammatory response, which in concert promote development of pathological alterations characteristic of most common neurodegenerative diseases.

Critical Issue: Accumulating recent evidence also suggests that there is an important interplay between the lipid endocannabinoid system (ECS; comprising of the main cannabinoid 1 and 2 receptors (CB1 and CB2), endocannabinoids and their synthetic and metabolizing enzymes) and various key inflammatory and redox-dependent processes.

FUTURE DIRECTIONS:

Targeting the ECS in order to modulate redox state-dependent cell death, and to decrease consequent or preceding inflammatory response holds therapeutic potential in multitude of oxidative stress-related acute or chronic neurodegenerative disorders from stroke and traumatic brain injury to Alzheimer`s and Parkinson`s diseases, and multiple sclerosis, just to name a few, which will be discussed in this overview.”

A chronic low dose of Δ9-tetrahydrocannabinol (THC) restores cognitive function in old mice

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“The balance between detrimental, pro-aging, often stochastic processes and counteracting homeostatic mechanisms largely determines the progression of aging. There is substantial evidence suggesting that the endocannabinoid system (ECS) is part of the latter system because it modulates the physiological processes underlying aging.

The activity of the ECS declines during aging, as CB1 receptor expression and coupling to G proteins are reduced in the brain tissues of older animals and the levels of the major endocannabinoid 2-arachidonoylglycerol (2-AG) are lower. However, a direct link between endocannabinoid tone and aging symptoms has not been demonstrated.

Here we show that a low dose of Δ9-tetrahydrocannabinol (THC) reversed the age-related decline in cognitive performance of mice aged 12 and 18 months. This behavioral effect was accompanied by enhanced expression of synaptic marker proteins and increased hippocampal spine density.

THC treatment restored hippocampal gene transcription patterns such that the expression profiles of THC-treated mice aged 12 months closely resembled those of THC-free animals aged 2 months. The transcriptional effects of THC were critically dependent on glutamatergic CB1 receptors and histone acetylation, as their inhibition blocked the beneficial effects of THC.

Thus, restoration of CB1 signaling in old individuals could be an effective strategy to treat age-related cognitive impairments.”

https://www.ncbi.nlm.nih.gov/pubmed/28481360

https://www.nature.com/nm/journal/vaop/ncurrent/full/nm.4311.html

“CAN MARIJUANA RESTORE MEMORY? NEW STUDY SHOWS CANNABIS CAN REVERSE COGNITIVE DECLINE IN MICE” http://www.newsweek.com/cannabis-marijuana-restores-memory-learning-cognitive-decline-596160

“A little cannabis every day might keep brain ageing at bay” https://www.newscientist.com/article/2130257-a-little-cannabis-every-day-might-keep-brain-ageing-at-bay/

“Low-dose cannabinoid THC restores memory and learning in old mice”  http://www.medicalnewstoday.com/articles/317342.php

“Daily Dose Of Cannabis May Protect And Heal The Brain From Effects Of Aging”  https://www.forbes.com/sites/janetwburns/2017/05/08/daily-dose-of-cannabis-may-protect-and-heal-the-brain-from-effects-of-aging/#70ef658f2e44

“Cannabis reverses aging processes in the brain”  https://medicalxpress.com/news/2017-05-cannabis-reverses-aging-brain.html

“Future dementia cure – Chemical in cannabis could REVERSE the ageing process” http://www.express.co.uk/life-style/health/801827/dementia-cure-cannabis-THC-chemical-memory

Editorial: The CB2 Cannabinoid System: A New Strategy in Neurodegenerative Disorder and Neuroinflammation

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“The cannabinoid receptors subtype 2 (CB2R) are emerging as novel targets for the development of new therapeutic approaches and PET probes useful to early diagnose neuroinflammation as first step in several neurodegenerative disorders such as Alzheimer’s disease (AD) and Parkinson disease (PD).

This Research Topic is mainly focused on the involvment of CB2R in neurodegenerative disorders and on the usefulness of CB2R ligands in the therapy and early diagnosis of neuroinflammation as onset of neurodegeneration.

In the reviews of Aso and Ferrer and Cassano et al. an interesting and exaustive overview of the endogenous cannabinoid signaling and its role in neuroinflammation and neurogenesis is reported. The potential of CB2R as therapeutic target in AD is argued by several evidences derived by robust experimental models and the effects modulated by CB2R agonists on different pathways involved in the pathogenesis of AD are discussed; indeed, these ligands are able to reduce inflammation, Aβ production and deposition, tau protein hyper-phosphorylation and oxidative stress damage caused by Aβ peptides. CB2R agonists are also able to induce Aβ clearance leading to cognitive improvement in AD models.

In conclusion, considering that neuroinflammation has been widely reported as indicator and modulator of neurodegeneration, the reduction of the neuroinflammatory responses could be considered as a new therapeutic strategy in these diseases. Moreover, the selective CB2R overexpression on the activated-microglial cells provides also a highly specialized target useful to an early diagnosis of the neurodegenerative diseases.”

http://journal.frontiersin.org/article/10.3389/fnins.2017.00196/full

Neurological aspects of medical use of cannabidiol.

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“Cannabidiol (CBD) is among the major secondary metabolites of Cannabis devoid of the delta-9-tetra-hydrocannabinol psychoactive effects. It is a resorcinol-based compound with a broad spectrum of potential therapeutic properties, including neuroprotective effects in numerous pathological conditions. CBD neuroprotection is due to its antioxidant and antiinflammatory activi-ties and the modulation of a large number of brain biological targets (receptors, channels) involved in the development and maintenance of neurodegenerative diseases.

OBJECTIVE:

Aim of the present review was to describe the state of art about the pre-clinical research, the potential use and, when existing, the clinical evidence related to CBD in the neurological field.

RESULTS:

Laboratory and clinical studies on the potential role of CBD in Parkinson’s disease (PD), Alzheimer’s disease (AD), multiple sclerosis (MS), Huntington’s disease (HD), amyotrophic lateral sclerosis ALS), cerebral ischemia, were examined.

CONCLUSIONS:

Pre-clinical evidence largely shows that CBD can produce beneficial effects in AD, PD and MS patients, but its employment for these disorders needs further confirmation from well designed clinical studies. CBD pre-clinical demonstration of antiepileptic activity is supported by recent clinical studies in human epileptic subjects resistant to standard antiepileptic drugs showing its potential use in children and young adults affected by refractory epilepsy. Evidence for use of CBD in PD is still not supported by sufficient data whereas only a few studies including a small number of patients are available.”

https://www.ncbi.nlm.nih.gov/pubmed/28412918

Cannabinoids therapeutic use: what is our current understanding following the introduction of THC, THC:CBD oromucosal spray and others?

 

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“The complexity of the endocannabinoid (eCB) system is becoming better understood and new drivers of eCB signaling are emerging. Modulation of the activities of the eCB system can be therapeutic in a number of diseases.

Research into the eCB system has been paralleled by the development of agents that interact with cannabinoid receptors. In this regard it should be remembered that herbal cannabis contains a myriad of active ingredients, and the individual cannabinoids have quite distinct biological activities requiring independent studies.

This article reviews the most important current data involving the eCB system in relation to human diseases, to reflect the present (based mainly on the most used prescription cannabinoid medicine, THC/CBD oromucosal spray) and potential future uses of cannabinoid-based therapy.

Expert commentary: From the different therapeutic possibilities, THC/CBD oromucosal spray has been in clinical use for approximately five years in numerous countries world-wide for the management of multiple sclerosis (MS)-related moderate to severe resistant spasticity.

Clinical trials have confirmed its efficacy and tolerability.

Other diseases in which different cannabinoids are currently being investigated include various pain states, Alzheimer’s disease, Parkinson’s disease, Huntington’s disease and epilepsy. The continued characterization of individual cannabinoids in different diseases remains important.”

https://www.ncbi.nlm.nih.gov/pubmed/28276775

MicroRNA-139 modulates Alzheimer’s-associated pathogenesis in SAMP8 mice by targeting cannabinoid receptor type 2.

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“Alzheimer’s disease (AD) is a neurodegenerative disorder, and is the most common type of dementia in the elderly population. Growing evidence indicates that microRNAs (miRNAs) play a crucial role in neuroinflammation associated with AD progression. In this study, we analyzed the expression of microRNA-139 (miR-139) as well as the learning and memory function in AD. We observed that the miR-139 expression was significantly higher in the hippocampus of aged senescence accelerated mouse prone 8 (SAMP8) mice (2.92 ± 0.13) than in the control mice (1.49 ± 0.08). Likewise, the overexpression of miR-139 by means of hippocampal injection impaired the hippocampus-dependent learning and memory formation. In contrast, the downregulation of miR-139 in mice improved learning and memory function in the mice. The level of cannabinoid receptor type 2 (CB2), a potential target gene of miR-139, was inversely correlated with the miR-139 expression in primary hippocampal cells. Furthermore, we demonstrated that miR-139 inversely modulated the responses to proinflammatory stimuli. Together, our findings demonstrate that miR-139 exerts a pathogenic effect in AD by modulating CB2-meditated neuroinflammatory processes.”

https://www.ncbi.nlm.nih.gov/pubmed/28218780

Acetylcholinesterase inhibitors in Alzheimer’s disease

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“Alzheimer’s Disease (AD) is the most common single cause of dementia in our ageing society. On full assessment and diagnosis of AD, initiation of an AChe inhibitor is recommended as early as possible, it is important that AChe inhibitor therapy is considered for patients with mild to moderate AD.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2014378/

“Characterization of Lignanamides from Hemp (Cannabis sativa L.) Seed and Their Antioxidant and Acetylcholinesterase Inhibitory Activities. Hempseed is known for its content in fatty acids, proteins and fiber, which contribute to its nutritional value. Lignanamides 2, 7, 9-14 showed good antioxidant activity among which 7, 10 and 13 also inhibited acetylcholinesterase in vitro. The new identified compounds in this study added to the diversity of hempseed composition and the bioassays implied that hempseed, with lignanamides as nutrients, may be a good source of bioactive and protective compounds.” http://www.ncbi.nlm.nih.gov/pubmed/26585089

“The Effects of Hempseed Meal Intake and Linoleic Acid on Drosophila Models of Neurodegenerative Diseases and Hypercholesterolemia. Our results indicate that hempseed meal (HSM) and linoleic acid are potential candidates for the treatment of Alzheimer’s disease (AD) and cardiovascular disease. These results show that HSM may prove of great utility as a health food, with potential for the prevention of AD and cardiovascular disease.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3933972/

In vivo Evidence for Therapeutic Properties of Cannabidiol (CBD) for Alzheimer’s Disease.

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“Alzheimer’s disease (AD) is a debilitating neurodegenerative disease that is affecting an increasing number of people. It is characterized by the accumulation of amyloid-β and tau hyperphosphorylation as well as neuroinflammation and oxidative stress.

Current AD treatments do not stop or reverse the disease progression, highlighting the need for new, more effective therapeutics.

Cannabidiol (CBD) is a non-psychoactive phytocannabinoid that has demonstrated neuroprotective, anti-inflammatory and antioxidant properties in vitro. Thus, it is investigated as a potential multifunctional treatment option for AD.

Here, we summarize the current status quo of in vivo effects of CBD in established pharmacological and transgenic animal models for AD.

The studies demonstrate the ability of CBD to reduce reactive gliosis and the neuroinflammatory response as well as to promote neurogenesis.

Importantly, CBD also reverses and prevents the development of cognitive deficits in AD rodent models.

Interestingly, combination therapies of CBD and Δ9-tetrahydrocannabinol (THC), the main active ingredient of cannabis sativa, show that CBD can antagonize the psychoactive effects associated with THC and possibly mediate greater therapeutic benefits than either phytocannabinoid alone.

The studies provide “proof of principle” that CBD and possibly CBD-THC combinations are valid candidates for novel AD therapies.” https://www.ncbi.nlm.nih.gov/pubmed/28217094

“It is unlikely that any drug acting on a single pathway or target will mitigate the complex pathoetiological cascade leading to AD. Therefore, a multifunctional drug approach targeting a number of AD pathologies simultaneously will provide better, wider-ranging benefits than current therapeutic approaches. Importantly, the endocannabinoid system has recently gained attention in AD research as it is associated with regulating a variety of processes related to AD, including oxidative stress, glial cell activation and clearance of macromolecules. The phytocannabinoid cannabidiol (CBD) is a prime candidate for this new treatment strategy. CBD has been found in vitro to be neuroprotective, to prevent hippocampal and cortical neurodegeneration, to have anti-inflammatory and antioxidant properties, reduce tau hyperphosphorylation and to regulate microglial cell migration. Furthermore, CBD was shown to protect against Aβ mediated neurotoxicity and microglial-activated neurotoxicity, to reduce Aβ production by inducing APP ubiquination and to improve cell viability,. These properties suggest that CBD is perfectly placed to treat a number of pathologies typically found in AD. The studies provide “proof of principle” that CBD and possibly CBD-THC combinations are valid candidates for novel AD therapies.” http://journal.frontiersin.org/article/10.3389/fphar.2017.00020/full