Category Archives: Brain Trauma

[Neuroprotective mechanisms of cannabinoids in brain ischemia and neurodegenerative disorders].

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“One of the most important causes of morbidity and mortality is neurologic dysfunction; its high incidence has led to an intense research of the mechanisms that protect the central nervous system from hypoxia and ischemia. The mayor challenge is to block the biochemical events leading to neuronal death.

This may be achieved by neuroprotective mechanisms that avoid the metabolic and immunologic cascades that follow a neurological damage. When it occurs, several pathophysiological events develop including cytokine release, oxidative stress and excitotoxicity.

Neuroprotective effects of cannabinoids to all those mechanisms have been reported in animal models of brain ischemia, excitotoxicity, brain trauma and neurodegenerative disorders.

Some endocannabinoid analogs are being tested in clinical studies (I-III phase) for acute disorders involving neuronal death (brain trauma and ischemia).

The study of the cannabinoid system may allow the discovery of effective neuroprotective drugs for the treatment of neurological disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/26299059

Cannabinoids in Neurodegenerative Disorders and Stroke/Brain Trauma: From Preclinical Models to Clinical Applications.

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“Cannabinoids form a singular family of plant-derived compounds (phytocannabinoids), endogenous signaling lipids (endocannabinoids), and synthetic derivatives with multiple biological effects and therapeutic applications in the central and peripheral nervous systems.

One of these properties is the regulation of neuronal homeostasis and survival, which is the result of the combination of a myriad of effects addressed to preserve, rescue, repair, and/or replace neurons, and also glial cells against multiple insults that may potentially damage these cells.

These effects are facilitated by the location of specific targets for the action of these compounds (e.g., cannabinoid type 1 and 2 receptors, endocannabinoid inactivating enzymes, and nonendocannabinoid targets) in key cellular substrates (e.g., neurons, glial cells, and neural progenitor cells).

This potential is promising for acute and chronic neurodegenerative pathological conditions. In this review, we will collect all experimental evidence, mainly obtained at the preclinical level, supporting that different cannabinoid compounds may be neuroprotective in adult and neonatal ischemia, brain trauma, Alzheimer’s disease, Parkinson’s disease, Huntington’s chorea, and amyotrophic lateral sclerosis.

This increasing experimental evidence demands a prompt clinical validation of cannabinoid-based medicines for the treatment of all these disorders, which, at present, lack efficacious treatments for delaying/arresting disease progression…”

http://www.ncbi.nlm.nih.gov/pubmed/26260390

Mitochondrial CB1 receptor is involved in ACEA-induced protective effects on neurons and mitochondrial functions.

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“Mitochondrial dysfunction contributes to cell death after cerebral ischemia/reperfusion (I/R) injury.

Cannabinoid CB1 receptor is expressed in neuronal mitochondrial membranes (mtCB1R) and involved in regulating mitochondrial functions under physiological conditions…

In purified neuronal mitochondria, mtCB1R activation attenuated Ca(2+)-induced mitochondrial injury.

In conclusion, mtCB1R is involved in ACEA-induced protective effects on neurons and mitochondrial functions, suggesting mtCB1R may be a potential novel target for the treatment of brain ischemic injury.”

http://www.ncbi.nlm.nih.gov/pubmed/26215450

Preclinical evaluation of SMM-189, a cannabinoid receptor 2-specific inverse agonist.

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“Cannabinoid receptor 2 agonists and inverse agonists are emerging as new therapeutic options for a spectrum of autoimmune-related disease.

Of particular interest, is the ability of CB2 ligands to regulate microglia function in neurodegenerative diseases and traumatic brain injury.

We have previously reported the receptor affinity of 3′,5′-dichloro-2,6-dihydroxy-biphenyl-4-yl)-phenyl-methanone (SMM-189) and the characterization of the beneficial effects of SMM-189 in the mouse model of mild traumatic brain injury.

Herein, we report the further characterization of SMM-189 as a potent and selective CB2 inverse agonist, which acts as a noncompetitive inhibitor of CP 55,940.

The ability of SMM-189 to regulate microglial activation, in terms of chemokine expression and cell morphology, has been determined.

Finally, we have determined that SMM-189 possesses acceptable biopharmaceutical properties indicating that the triaryl class of CB2 inverse agonists are viable compounds for continued preclinical development for the treatment of neurodegenerative disorders and traumatic brain injury.”

http://www.ncbi.nlm.nih.gov/pubmed/26196013

Ultralow doses of cannabinoid drugs protect the mouse brain from inflammation-induced cognitive damage.

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“In our previous studies, we found that a single ultralow dose of tetrahydrocannabinol (THC)… protects the brain from different insults that cause cognitive deficits.

Because various insults may trigger a neuroinflammatory response that leads to secondary damage to the brain, the current study tested whether this extremely low dose of THC could protect the brain from inflammation-induced cognitive deficits…

Our results suggest that an ultralow dose of THC that lacks any psychotrophic activity protects the brain from neuroinflammation-induced cognitive damage and might be used as an effective drug for the treatment of neuroinflammatory conditions, including neurodegenerative diseases.”

http://www.ncbi.nlm.nih.gov/pubmed/25042014

Combined neuroprotective action of adenosine A1 and cannabinoid CB1 receptors against NMDA-induced excitotoxicity in the hippocampus.

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“Both adenosine A1 and cannabinoid CB1 receptors trigger similar transduction pathways and protect against neurotoxic insults at the hippocampus, but their combined neuroprotective potential has not been investigated.

We set forth to assess the combined action of A1 and CB1 receptors against glutamate NMDA receptor-mediated excitotoxicity at the hippocampus…

The results suggest that both CB1 and A1 receptors produce additive cumulative neuroprotection against NMDA-induced excitotoxicity in the hippocampus.”

http://www.ncbi.nlm.nih.gov/pubmed/26065937

New horizons for newborn brain protection: enhancing endogenous neuroprotection.

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“Intrapartum-related events are the third leading cause of childhood mortality worldwide and result in one million neurodisabled survivors each year. Infants exposed to a perinatal insult typically present with neonatal encephalopathy (NE).

The contribution of pure hypoxia-ischaemia (HI) to NE has been debated; over the last decade, the sensitising effect of inflammation in the aetiology of NE and neurodisability is recognised.

Therapeutic hypothermia is standard care for NE in high-income countries; however, its benefit in encephalopathic babies with sepsis or in those born following chorioamnionitis is unclear.

It is now recognised that the phases of brain injury extend into a tertiary phase, which lasts for weeks to years after the initial insult and opens up new possibilities for therapy.

There has been a recent focus on understanding endogenous neuroprotection and how to boost it or to supplement its effectors therapeutically once damage to the brain has occurred as in NE.

In this review, we focus on strategies that can augment the body’s own endogenous neuroprotection.

We discuss in particular remote ischaemic postconditioning whereby endogenous brain tolerance can be activated through hypoxia/reperfusion stimuli started immediately after the index hypoxic-ischaemic insult.

Therapeutic hypothermia, melatonin, erythropoietin and cannabinoids are examples of ways we can supplement the endogenous response to HI to obtain its full neuroprotective potential.

Achieving the correct balance of interventions at the correct time in relation to the nature and stage of injury will be a significant challenge in the next decade.”

http://www.ncbi.nlm.nih.gov/pubmed/26063194

Cannabinoid receptor 2 attenuates microglial accumulation and brain injury following germinal matrix hemorrhage via ERK dephosphorylation in vivo and in vitro.

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“Microglia accumulation plays detrimental roles in the pathology of germinal matrix hemorrhage (GMH) in the immature preterm brain.

Here, we investigated the effects of a cannabinoid receptor 2 (CB2R) agonist on microglia proliferation and the possible involvement of the mitogen-activated protein kinase (MAPK) family pathway in a collagenase-induced GMH rat model and in thrombin-induced rat microglia cells.

Overall, these findings suggest that activation of the endocannabinoid system might attenuate inflammation-induced secondary brain injury after GMH in rats by reducing microglia accumulation through a mechanism involving ERK dephosphorylation.

Enhancing CB2R activation is a potential treatment to slow down the course of GMH in preterm newborns.”

http://www.ncbi.nlm.nih.gov/pubmed/25963415

http://www.thctotalhealthcare.com/category/brain-trauma/

 

A Basal Tone of 2-Arachidonoylglycerol Contributes to Early Oligodendrocyte Progenitor Proliferation by Activating Phosphatidylinositol 3-Kinase (PI3K)/AKT and the Mammalian Target of Rapamycin (MTOR) Pathways.

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“A basal tone of the endocannabinoid 2-arachidonoylglycerol (2-AG) enhances late oligodendrocyte progenitor cell (OPC) differentiation. Here, we investigated whether endogenous 2-AG may also promote OPC proliferation in earlier stages…

Our data suggest that proliferation of early OPCs stimulated by PDGF-AA and bFGF depends on the tonic activation of cannabinoid receptors by endogenous 2-AG and provide further evidence on the role of endocannabinoids in oligodendrocyte development, being important for the maintenance and self-renewal of the OPCs.

The results highlight the therapeutic potential of the endocannabinoid signaling in the emerging field of brain repair.”

http://www.ncbi.nlm.nih.gov/pubmed/25900077

The interactive role of cannabinoid and vanilloid systems in hippocampal synaptic plasticity in rats.

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“Long-term potentiation (LTP) has been most thoroughly studied in the hippocampus, which has a key role in learning and memory. Endocannabinoids are one of the endogenous systems that modulate this kind of synaptic plasticity. The activation of the vanillioid system has also been shown to mediate synaptic plasticity in the hippocampus. In addition, immunohistochemical studies have shown that cannabinoid receptor type 1 (CB1) and vanilloid receptor 1 (TRPV1) are closely located in the hippocampus.

It seems that agonists of the vanilloid system modulate cannabinoid outputs that cause an increase in synaptic plastisity, while in contemporary consumption of two agonist, TRPV1 agonist can change production of endocannabinoid, which in turn result to enhancement of LTP induction. These findings suggest that the two systems may interact or share certain common signaling pathways in the hippocampus.”

http://www.ncbi.nlm.nih.gov/pubmed/25843413