Mechanisms of control of neuron survival by the endocannabinoid system.

“Endocannabinoids act as retrograde messengers that, by inhibiting neurotransmitter release via presynaptic CB(1) cannabinoid receptors, regulate the functionality of many synapses. In addition, the endocannabinoid system participates in the control of neuron survival.

Thus, CB(1) receptor activation has been shown to protect neurons from acute brain injury as well as in neuroinflammatory conditions and neurodegenerative diseases.

Cannabinoid neuroprotective activity relies on the inhibition of glutamatergic neurotransmission and on other various mechanisms, and is supported by the observation that the brain overproduces endocannabinoids upon damage.

Besides promoting neuroprotection, a role for the endocannabinoid system in the control of neurogenesis from neural progenitors has been put forward. In addition, activation of CB(2) cannabinoid receptors on glial cells may also participate in neuroprotection by limiting the extent of neuroinflammation.

Altogether, these findings support that endocannabinoids constitute a new family of lipid mediators that act as instructive signals in the control of neuron survival.”

http://www.ncbi.nlm.nih.gov/pubmed/18781978

Cannabinoids and Neuroprotection in Stroke

“One of the most recently described neural signaling systems is that mediated by endogenous cannabinoids (endocannabinoids). Cannabinoids have recently been shown to attenuate neuronal injury induced by hypoxia and glucose deprivation in cell culture, as well as injury induced in rat brain following both global and focal cerebral ischemia in vivo.

Two endocannabinoids have been characterized in detail: N-arachidonylethanolamide and 2-arachidonylglycerol. Cannabinoid CB1 and CB2receptors have been cloned and an alternatively spliced CB1A isoform has been identified.

The development of metabolically stable, synthetic, enantiomeric cannabinoid receptor agonists and of CB1 and CB2 receptor antagonists has greatly aided the characterization of cannabinoid receptor-mediated processes, although certain aspects of cannabinoid signaling in some systems remain poorly understood.

Indirect evidence suggests that cannabinoids might serve as endogenous regulators of ischemic neuronal injury, but several recent reports provide more direct evidence bearing on such a role.

The author’s own findings provide evidence for CB1 receptor-mediated neuroprotection in vivo, but non-receptor-mediated protection in vitro.”

http://journals.prous.com/journals/servlet/xmlxsl/pk_journals.xml_summary_pr?p_JournalId=3&p_RefId=129&p_IsPs=Y

Experimental autoimmune encephalomyelitis disrupts endocannabinoid-mediated neuroprotection

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“Focal cerebral ischemia and traumatic brain injury induce an escalating amount of cell death because of harmful mediators diffusing from the original lesion site.

Evidence suggests that healthy cells surrounding these lesions attempt to protect themselves by producing endocannabinoids (eCBs) and activating cannabinoid receptors, the molecular target for marijuana-derived compounds.

Indeed, activation of cannabinoid receptors reduces the production and diffusion of harmful mediators.

Here, we provide evidence that an exception to this pattern is found in experimental autoimmuneencephalomyelitis (EAE), a mouse model of multiple sclerosis…

Our data suggest that the high level of CNS IFN-gamma associated with EAE disrupts eCB-mediated neuroprotection while maintaining functional cannabinoid receptors, thus providing additional support for the use of cannabinoid-based medicine to treat multiple sclerosis.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1458883/

Targeting the Endocannabinoid System for Neuroprotection: A 19F-NMR Study of a Selective FAAH Inhibitor Binding with an Anandamide Carrier Protein, HSA.

“Fatty acid amide hydrolase (FAAH), the enzyme involved in the inactivation of the endocannabinoid anandamide (AEA), is being considered as a therapeutic target for analgesia and neuroprotection…
The endocannabinoid system has been implicated as a therapeutic target for analgesia, anti-emesis, and neuroprotection… These findings provide a potential new therapeutic modality for neuroprotection through dual inhibition of FAAH and anandamide carrier proteins…”

Figure 1

Neuroprotection and reduction of glial reaction by cannabidiol treatment after sciatic nerve transection in neonatal rats.

“The clinical use of neurotrophic factors is difficult due to side effects and elevated costs, but other molecules might be effective and more easily obtained. Among them, some are derived from Cannabis sativa.

Cannabidiol (CBD) is the major non-psychotropic component found on the surface of such plant leaves.

The present study aimed to investigate the neuroprotective potential of CBD…

The present results show that CBD possesses neuroprotective characteristics that may, in turn, be promising for future clinical use.”

http://www.ncbi.nlm.nih.gov/pubmed/23981015

Can medical herbs stimulate regeneration or neuroprotection and treat neuropathic pain in chemotherapy-induced peripheral neuropathy?

“Chemotherapy-induced neuropathy (CIPN) has a relevant impact on the quality of life of cancer patients. There are no curative conventional treatments, so further options have to be investigated. We conducted a systematic review in English and Chinese language databases to illuminate the role of medical herbs. 26 relevant studies on 5 single herbs, one extract, one receptor-agonist, and 8 combinations of herbs were identified focusing on the single herbs Acorus calamus rhizoma, Cannabis sativa fructus, Chamomilla matricaria, Ginkgo biloba, Salvia officinalis, Sweet bee venom, Fritillaria cirrhosae bulbus, and the herbal combinations Bu Yang Huan Wu, modified Bu Yang Huan Wu plus Liuwei Di Huang, modified Chai Hu Long Gu Mu Li Wan, Geranii herba plus Aconiti lateralis praeparata radix , Niu Che Sen Qi Wan (Goshajinkigan), Gui Zhi Jia Shu Fu Tang (Keishikajutsubuto), Huang Qi Wu Wu Tang (Ogikeishigomotsuto), and Shao Yao Gan Cao Tang (Shakuyakukanzoto). The knowledge of mechanism of action is still limited, the quality of clinical trials needs further improvement, and studies have not yielded enough evidence to establish a standard practice, but a lot of promising substances have been identified.

While CIPN has multiple mechanisms of neuronal degeneration, a combination of herbs or substances might deal with multiple targets for the aim of neuroprotection or neuroregeneration in CIPN.”

http://www.ncbi.nlm.nih.gov/pubmed/23983777

Cannabidiol Normalizes Caspase 3, Synaptophysin, and Mitochondrial Fission Protein DNM1L Expression Levels in Rats with Brain Iron Overload: Implications for Neuroprotection.

“We have recently shown that chronic treatment with cannabidiol (CBD) was able to recover memory deficits induced by brain iron loading in a dose-dependent manner in rats.

 Brain iron accumulation is implicated in the pathogenesis of neurodegenerative diseases, including Parkinson’s and Alzheimer’s, and has been related to cognitive deficits in animals and human subjects.

…we have analyzed the expression level of brain proteins involved with mitochondrial fusion and fission mechanisms (DNM1L and OPA1), the main integral transmembrane protein of synaptic vesicles (synaptophysin), and caspase 3, an apoptosis-related protein, to gain a better understanding of the potential of CBD in restoring the damage caused by iron loading in rats.

We found that CBD rescued iron-induced effects…

Our results suggest that iron affects mitochondrial dynamics, possibly trigging synaptic loss and apoptotic cell death and indicate that CBD should be considered as a potential molecule with memory-rescuing and neuroprotective properties to be used in the treatment of cognitive deficits observed in neurodegenerative disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/23893294

Cannabis Use, Effect And Potential Therapy For Alzheimer’s, MS and Parkinson’s

“The illegal status and wide-spread use of cannabis made basic and clinical cannabis research difficult in the past decades; on the other hand, it has stimulated efforts to identify the psychoactive constituents of cannabis. As a consequence, the endocannabinoid system was discovered, which was shown to be involved in most physiological systems — the nervous, the cardiovascular, the reproductive, the immune system, to mention a few.

One of the main roles of endocannabinoids is neuroprotection, but over the last decade they have been found to affect a long list of processes, from anxiety, depression, cancer development, vasodilatation to bone formation and even pregnancy.

Cannabinoids and endocannabinoids are supposed to represent a medicinal treasure trove which waits to be discovered…

The endocannabinoid system acts as a guardian against various attacks on the mammalian body.

Conclusion

The above described research concerning the endocannabinoid-system is of importance in both basic science and in therapeutics:

  • The discovery of the cannabis plant active constituent has helped advance our understanding of cannabis use and its effects.
  • The discovery of the endocannabinoids has been of central importance in establishing the existence of a new biochemical system and its physiological roles — in particular in neuroprotection.
  • These discoveries have opened the door for the development of novel types of drugs, such as THC for the treatment of nausea and for enhancing appetite in cachectic patients.
  • The endocannabinoid system is involved in the protective reaction of the mammalian body to a long list of neurological diseases such as multiple sclerosis, Alzheimer’s and Parkinson’s disease which raises hope for novel therapeutic opportunities for these diseases.”

More: http://www.sciencedaily.com/releases/2007/10/071014163644.htm

Cannabinoid receptor subtypes 1 and 2 mediate long-lasting neuroprotection and improve motor behavior deficits after transient focal cerebral ischemia.

“The endocannabinoid system is crucially involved in the regulation of brain activity and inflammation… we show that the endocannabinoid system assembles a comprehensive machinery to defend the brain against the devastating consequences of cerebral ischemia.

 In summary, this study underlines the therapeutic potential of CB1 and/or CB2 receptor agonists against neurodegenerative diseases or injuries involving acute or chronic imbalances of cerebral blood flow and energy consumption.”

http://www.ncbi.nlm.nih.gov/pubmed/23069763

The role of CB1 in immune modulation by cannabinoids.

“There is clear evidence that CB(2), historically referred to as the peripheral cannabinoid receptor, mediates many of the immune modulatory effects of cannabinoids.

 However, cannabinoid receptors cannot be classified simply as central or peripheral since CB(2) has been shown to play a role in the central nervous system (CNS) and CB(1) mediates many immune system effects. Although Cnr1 mRNA and CB(1) protein expression is lower than Cnr2 mRNA or CB(2) protein expression in cells of the immune system, several studies have shown direct modulation of immune function via CB(1) by endogenous and exogenous cannabinoids in T cells, innate cells, and to a lesser extent, B cells.

In addition, indirect, but CB(1)-dependent, mechanisms of immune modulation exist. In fact, the mechanism by which cannabinoids attenuate neuroinflammation via CB(1) is likely a combination of immune suppression and neuroprotection.

 Although many studies demonstrate that agonists for CB(1) are immune suppressive and anti-inflammatory, CB(1) antagonists also exhibit anti-inflammatory properties. Overall, the data demonstrate that many of the immune modulatory effects of cannabinoids are mediated via CB(1).”

http://www.ncbi.nlm.nih.gov/pubmed/23261520