“The blood-brain barrier (BBB) disruption and the following development of brain edema, is the most life-threatening secondary injury after intracerebral hemorrhage (ICH).
This study is to investigate a potential role and mechanism of JWH133, a selected cannabinoid receptor type2 (CB2R) agonist, on protecting blood-brain barrier integrity after ICH.
CB2R agonist alleviated neuroinflammation and protected blood-brain barrier permeability in a rat ICH model. Further molecular mechanisms revealed which is probably mediated by enhancing the expression of MKP-1, then inhibited MAPKs signal transduction.”
“MAGL (monoacylglycerol lipase) is an enzyme that hydrolyzes the endocannabinoid 2-arachidonoylglycerol and regulates the production of arachidonic acid and prostaglandins-substances that mediate tissue inflammatory response. Here, we have studied the effects of the selective MAGL inhibitors JZL184 and MJN110 and their underlying molecular mechanisms on 3 different experimental models of focal cerebral ischemia.
Pharmacological inhibition of MAGL significantly attenuated infarct volume and hemispheric swelling. MAGL inhibition also ameliorated sensorimotor deficits, suppressed inflammatory response, and decreased the number of degenerating neurons. These beneficial effects of MAGL inhibition were not fully abrogated by selective antagonists of cannabinoid receptors, indicating that the anti-inflammatory effects are caused by inhibition of eicosanoid production rather than by activation of cannabinoid receptors.
Our results suggest that MAGL may contribute to the pathophysiology of focal cerebral ischemia and is thus a promising therapeutic target for the treatment of ischemic stroke.”
“Ischemia not only activates cell death pathways but also triggers endogenous protective mechanisms. However, it is largely unknown what is the essence of the endogenous neuroprotective mechanisms induced by preconditioning. In this study we demonstrated that systemic injection of JZL195, a selective inhibitor of eCB clearance enzymes, induces in vivo long-term depression at CA3-CA1 synapses and at PrL-NAc synapses produces neuroprotection. JZL195-elicited long-term depression is blocked by AM281, the antagonist of cannabinoid 1 receptor (CB1R) and is abolished in mice lacking cannabinoid CB1 receptor (CB1R) in astroglial cells, but is conserved in mice lacking CB1R in glutamatergic or GABAergic neurons. Blocking the glutamate NMDA receptor and the synaptic trafficking of glutamate AMPA receptor abolishes both long-term depression and neuroprotection induced by JZL195. Mice lacking CB1R in astroglia show decreased neuronal death following cerebral ischemia. Thus, an acute elevation of extracellular eCB following eCB clearance inhibition results in neuroprotection through long-term depression induction after sequential activation of astroglial CB1R and postsynaptic glutamate receptors.”
“Although the number of individuals suffering from stroke in the United States and worldwide will continue to grow, therapeutic intervention for treatment following stroke remains frustratingly limited.
Both the cannabinoid 1 receptor (CB1R) and the cannabinoid 2 receptor (CB2R) have been studied in relationship to stroke. Deletion of the CB2R has been shown to worsen outcome, while selective CB2R agonists have been demonstrated to be neuroprotective following stroke.
We tested the hypothesis that CB1/CB2 receptor double knockout would produce significant increases in infarct size and volume and significant worsening in clinical score, using two mouse models, one of permanent ischemia and one of ischemia/reperfusion.
The results surprisingly revealed that CB1/CB2 double knockout mice showed improved outcomes, with the most improvements in the mouse model of permanent ischemia.
Although initial studies of CB1R knockout mice demonstrated increased injury following stroke, indicating that activation of the CB1R was neuroprotective, later studies of selective antagonists of the CB1R also demonstrated a protective effect.
Surprisingly the double knockout animals had improved outcome.
Since the phenotype of the double knockout is not dramatically changed, significant changes in the contribution of other homeostatic pathways in compensation for the loss of these two important receptors may explain these apparently contradictory results.”
“Introduction: The endocannabinoid system (ECS) regulates functions throughout human physiology, including neuropsychiatric, cardiovascular, autonomic, metabolic, and inflammatory states. The complex cellular interactions regulated by the ECS suggest a potential for vascular disease and stroke prevention by augmenting central nervous and immune cell endocannabinoid signaling.
Discussion: The endocannabinoid N-arachidonoylethanolamine (anandamide) plays a central role in augmenting these processes in cerebrovascular and neurometabolic disease. Furthermore, cannabidiol (CBD), a nonpsychoactive constituent of Cannabis, is an immediate therapeutic candidate both for potentiating endocannabinoid signaling and for acting at multiple pharmacological targets.
Conclusion: This speculative synthesis explores the current state of knowledge of the ECS and suggests CBD as a therapeutic candidate for stroke prevention by exerting favorable augmentation of the homeostatic effects of the ECS and, in turn, improving the metabolic syndrome, while simultaneously stalling the development of atherosclerosis.”
“Spasticity is a common neurologic condition in patients with multiple sclerosis, stroke, cerebral palsy or an injured spinal cord. Animal studies suggest that THC has an inhibitory effect on polysynaptic reflexes.
Some spastic patients claim improvement after inhaling cannabis. We tested muscle tone, reflexes, strength and performed EMGs before and after double-blinded oral administration of either 10 or 5 mg THC or placebo.
10 mg THC significantly reduced spasticity by clinical measurement (P less than 0.01).
Responses varied, but benefit was seen in three of three patients with “tonic spasms.””
“Stroke is a neurological disease, which, in addition to high mortality, imposes many financial and mental burdens on families and the society.
The main objective of this study was to investigate the effect of cannabidiol (CBD) on one of the major inflammatory pathways in cerebral ischaemia.
Administration of CBD (100 and 200 ng/rat) caused a significant reduction in infarction, brain oedema, and BBB permeability compared with the vehicle-received group. Down-regulation of TNF-α, TNFR1, and NF-кB expression was also observed by CBD.
The results achieved in this study support the idea that CBD has a cerebroprotective effect (partly through suppression of TNF-α, TNFR1, and NF-кB) on ischaemic injury.”
“Smoking marijuana can reduce the risk of a stroke to a large extent, a new study has found. In the states where marijuana use is legal, strains of the drug are prescribed to cure chronic pain, anxiety, and epilepsy. A new study conducted by the University of Texas at Dallas has found cannabis can improve a person’s health by enhancing the blood and oxygen flow, thus reducing the risk of blood clots and the possibility of a stroke.” http://www.ibtimes.com/smoking-marijuana-can-reduce-risk-stroke-study-finds-2579489
“Could cannabis PROTECT you from a stroke? People who smoke marijuana every day have better blood flow and oxygen to the brain, controversial study claims. A study by the University of Texas at Dallas has found the drug can improve oxygen and blood flow to the brain, reducing the risk of clots that cause a brain attack. In fact, the research team found chronic cannabis users have the most efficient brain blood flow of all, suggesting their stroke risk is lowest.” http://www.dailymail.co.uk/health/article-4797444/Cannabis-PROTECTS-stroke-study-claims.html
“The astrocytes have gained in recent decades an enormous interest as a potential target for neurotherapies, due to their essential and pleiotropic roles in brain physiology and pathology. Their precise regulation is still far from understood, although several candidate molecules/systems arise as promising targets for astrocyte-mediated neuroregulation and/or neuroprotection.
The cannabinoid system and its ligands have been shown to interact and affect activities of astrocytes. Cannabidiol (CBD) is the main non-psychotomimetic cannabinoid derived from Cannabis. CBD is devoid of direct CB1 and CB2 receptor activity, but exerts a number of important effects in the brain. Here, we attempt to sum up the current findings on the effects of CBD on astrocyte activity, and in this way on central nervous system (CNS) functions, across various tested models and neuropathologies.
The collected data shows that increased astrocyte activity is suppressed in the presence of CBD in models of ischemia, Alzheimer-like and Multiple-Sclerosis-like neurodegenerations, sciatic nerve injury, epilepsy, and schizophrenia. Moreover, CBD has been shown to decrease proinflammatory functions and signaling in astrocytes.”
“Recent studies demonstrated that cannabidiol had neuroprotective property. There is some evidence about effective role of cannabidiol in reduction of ischemic damages. It has been reported that infarct size is influenced by various factors after MCAO, including inflammatory factors. The aim of the present study was to evaluate the effect of cannabidiol on infarction volume and correlation of infarct size with tumor necrosis factor receptor 1 (TNFR1), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) expression.
The present results indicate that in the MCAO-induced cerebral ischemia, administration of cannabidiol (100 and 200 ng/rat) causes a significant reduction in infarction volume in comparison with the vehicle group. Also, there were significant correlations between decrease of regional infarct volume and TNFR1/NF-κB expression.
The results of this study indicate that cannabidiol reduced cerebral infarction possibly through diminishing TNFR1/NF-κB-induced neurotoxicity in transient focal cerebral ischemia.”