“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.
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.”
“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.”
“It has been suggested that the endocannabinoid system elicits neuroprotection against excitotoxic brain damage.
In the present study the therapeutic potential of AM 404 on ischaemia-induced neuronal injury was investigated in vivo and compared with that of the classical cannabinoid receptor type 1 (CB1) agonist, Δ9-tetraydrocannabinol (THC), using a model of transient global cerebral ischaemia in the gerbil.
Our findings demonstrate that AM 404 and THC reduce neuronal damage caused by bilateral carotid occlusion in gerbils and that this protection is mediated through an interaction with CB1 and opioid receptors.
Endocannabinoids might form the basis for the development of new neuroprotective drugs useful for the treatment of stroke and other neurodegenerative pathologies.
There is some evidence from experiments with mice that increasing anandamide or 2-arachidonoyl glycerol content may lead to neuroprotection.
Collectively, our data demonstrate that AM 404 and THC protect against neuronal ischaemia-induced injury through a mechanism involving cannabinoid and opioid receptors but not vanilloid receptors.”
“Pathophysiological conditions such as obesity and type 2 diabetes (T2D) are reportedly associated to over-activation of the endocannabinoid system (ECS). Therefore, modulation of the ECS offers potential therapeutic benefits on those diseases. GPR55, the receptor for L-α-lysophosphatidylinositol (LPI) that has also affinity for various cannabinoid ligands, is distributed at the central and peripheral level and it is involved in several physiological processes. This review summarizes the localization and role of GPR55 in tissues that are crucial for the regulation of glucose metabolism, and provides an update on its contribution in obesity and insulin resistance. The therapeutic potential of targeting the GPR55 receptor is also discussed.”
“Inflammatory bowel diseases (IBD) are disorders of chronic intestinal inflammation of unknown etiology. The basic pathophysiological process is that of immune mediated inflammation affecting the intestinal tract. This process is dependent on and governed by both genetic and environmental factors. There are two distinct forms of IBD – ulcerative colitis and Crohn’s disease.
There is no curative medical treatment. Furthermore, over 30% of patients, and over 70% with Crohn’s disease, will need surgical intervention for their disease. Thus, it comes as no surprise that many patients will turn to complementary or alternative medicine at some stage of their disease. Recent information reveals that between 16% and 50% of patients admit to having tried marijuana for their symptoms.
There is a long list of gastrointestinal symptoms that have been reported to be relieved by cannabis. These include anorexia, nausea, abdominal pain, diarrhea, gastroparesis – all of which can be part of IBD. These effects are related to the fact that the gastrointestinal tract is rich in cannabinoid (CB) receptors and their endogenous ligands, comprising together the endocannabinoid system (ECS).
In conclusion, use of cannabis is common in IBD, and it seems to be mostly safe. Accumulating preliminary data from human studies support a beneficial role of cannabinoids in IBD.”
“The endocannabinoid (eCB) system has attracted attention for its role in various behavioral and brain functions, and as a therapeutic target in neuropsychiatric disease states, including anxiety disorders and other conditions resulting from dysfunctional responses to stress. In this mini-review, we highlight components of the eCB system that offer potential ‘druggable’ targets for new anxiolytic medications, emphasizing some of the less well-discussed options. We discuss how selectively amplifying eCBs recruitment by interfering with eCB-degradation, via fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), has been linked to reductions in anxiety-like behaviors in rodents and variation in human anxiety symptoms. We also discuss a non-canonical route to regulate eCB degradation that involves interfering with cyclooxygenase-2 (COX-2). Next, we discuss approaches to targeting eCB receptor-signaling in ways that do not involve the cannabinoid receptor subtype 1 (CB1R); by targeting the CB2R subtype and the transient receptor potential vanilloid type 1 (TRPV1). Finally, we review evidence that cannabidiol (CBD), while representing a less specific pharmacological approach, may be another way to modulate eCBs and interacting neurotransmitter systems to alleviate anxiety. Taken together, these various approaches provide a range of plausible paths to developing novel compounds that could prove useful for treating trauma-related and anxiety disorders.”
“Exogenous cannabinoids such as marijuana exert their influence through cannabinoid receptors. Endogenous cannabinoids such as anandamide (AEA) function through the same receptors, and their physiological roles are a subject of intense study. Here, we show that AEA plays a pivotal role in maintaining immunological health in the gut. The immune system in the gut actively tolerates the foreign antigens present in the gut through mechanisms that are only partially understood. We show that AEA contributes to this critical process by promoting the presence of CX3CR1hi macrophages, which are immunosuppressive. These results uncover a major conversation between the immune and nervous systems. In addition, with the increasing prevalence of ingestion of exogenous marijuana, our study has significant implications for public health.” http://www.pnas.org/content/early/2017/04/18/1612177114.full
“Our study unveils a role for the endocannabinoid system in maintaining immune homeostasis in the gut/pancreas and reveals a conversation between the nervous and immune systems using distinct receptors.” https://www.ncbi.nlm.nih.gov/pubmed/28439004
“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.”
“Previously, we presented electrophysiological evidence for presence in mice brain slices of functional cannabinoid type I receptors (CB1Rs) within the laterodorsal tegmentum (LDT), a brain stem nucleus critical in control of arousal and rapid eye movement (REM) sleep. Further, using pharmacological agents, we provided data suggestive of the endogenous presence of cannabinoids (CBs) acting at LDT CB1Rs. However, in those studies, we were unable to identify the type(s) of CB ligands endogenously present in the LDT, and this information has not been provided elsewhere. Accordingly, we used the highly-sensitive liquid chromatography/mass spectrometry (LC-MS) method to determine whether N-arachidonoylethanolamide (Anandamide or AEA) and 2-arachidonyl glycerol (2-AG), which are both endogenous CB ligands acting at CB1Rs, are present in the LDT. Mice brain tissue samples of the LDT were assayed using ion trap LC-MS in selected ion monitoring mode. Chromatographic analysis and product-ion MS scans identified presence of the CBs, AEA and 2-AG, from LDT mouse tissue. Data using the LC-MS method show that AEA and 2-AG are endogenously present within the LDT and when coupled with our electrophysiological findings, lead to the suggestion that AEA and 2-AG act at electropharmacologically-demonstrated CB1Rs in this nucleus. Accordingly, AEA and 2-AG likely play a role in processes governed by the LDT, including control of states of cortical gamma band activity seen in alert, aroused states, as well as cortical and motor activity characteristic of REM sleep.”
“We recently uncovered a signaling mechanism by which the endocannabinoid anandamide mediates the action of oxytocin, a neuropeptide that is crucial for social behavior, to control social reward. Oxytocin signaling has been implicated in autism spectrum disorder (ASD), and social reward is a key aspect of social functioning that is thought to be disrupted in ASD. Therefore, as a proof of principle for the core component of ASD—social impairment—we tested an endocannabinoid-enhancing compound on two widely studied mouse models of ASD, the BTBR and fmr1−/− (model of Fragile X Syndrome).
Remarkably, we found that FAAH blockade completely reversed the social impairment in both mouse models. CB1 receptor blockade prevented the prosocial action of FAAH inhibition in BTBR mice.
The results suggest that increasing anandamide activity at CB1 receptors improves ASD-related social impairment and identify FAAH as a novel therapeutic target for ASD.
In conclusion, the present study provides new insights into the role of endocannabinoid signaling in social behavior and validates FAAH as a novel therapeutic target for the social impairment of ASD.”