“These data suggest that CB2 overexpression may contribute to the regression of human anaplastic thyroid tumor… Given that cannabinoids have shown antitumor effects in many types of cancer models, CB2 may be a viable therapeutic target for the treatment of anaplastic thyroid carcinoma.”
“Cannabinoid receptor type 2 (CBR2) inhibits microglial reactivity through a molecular mechanism yet to be elucidated. We hypothesized that CBR2 activation induces an anti-inflammatory phenotype in microglia by inhibiting extracellular signal-regulated kinase (ERK) pathway, via mitogen-activated protein kinase-phosphatase (MKP) induction. MKPs regulate mitogen activated protein kinases, but their role in the modulation of microglial phenotype is not fully understood.”
“Our results uncover a cellular microglial pathway triggered by CBR2 activation. These data suggest that the reduction of pro-inflammatory factors and microglial migration via MKP-3 induction is part of the mechanism of action of CBR2 agonists. These findings may have clinical implications for further drug development.”
“In summary, our current results uncovered a cellular mechanism of action of CBR2 agonists that produces a microglial anti-inflammatory phenotype, which may modulate microglial motility in vivo. We identified MKP-3 and microglial migration as potential new targets for drug development. The clinical utility of CBR2 agonists is supported by their analgesic efficacy and their lack of neurological side effects in animal models of postoperative or neuropathic pain.”
“Activation of cannabinoid CB(2) receptors attenuates thermal nociception in untreated animals while failing to produce centrally mediated effects such as hypothermia and catalepsy. The present study was conducted to test the hypothesis that activation of CB(2) in the periphery suppresses the development of inflammatory pain as well as inflammation-evoked neuronal activity at the level of the CNS…”
“These data provide evidence that actions at cannabinoid CB(2) receptors are sufficient to suppress inflammation-evoked neuronal activity at rostral levels of processing in the spinal dorsal horn…”
“We tested if cannabinoid type 2 receptor (CB2) in the central nervous system plays a role in alcohol abuse/dependence in animal model and then examined an association between the CB2 gene polymorphism and alcoholism in human. Mice experiencing more alcohol preference by drinking showed reduced Cb2 gene expression, whereas mice with little preference showed no changes of it in ventral midbrain. Alcohol preference in conjunction with chronic mild stress were enhanced in mice treated with CB2 agonist JWH015 when subjected to chronic stress, whereas antagonist AM630 prevented development of alcohol preference. There is an association between the Q63R polymorphism of the CB2 gene and alcoholism in a Japanese population (P=0.007; odds ratio 1.25, 95% CI, (1.06-1.47)). CB2 under such environment is associated with the physiologic effects of alcohol and CB2 antagonists may have potential as therapies for alcoholism.”
“Since the discovery of the cannabinoid CB1 receptor (CB1R) in 1988, and subsequently of the CB2 receptor (CB2R) in 1993, there has been an exponential growth of research investigating the functions of the endocannabinoid system. The roles of CB1Rs have been of particular interest to psychiatry because of their selective presence within the CNS and because of their association with brain-reward circuits involving mesocorticolimbic dopamine systems. One potential role that has become of considerable focus is the ability of CB1Rs to modulate the effects of the drugs of abuse. Many drugs of abuse elevate dopamine levels, and the ability of CB1R antagonists or inverse agonists to modulate these elevations has suggested their potential application as pharmacotherapies for treating drug abuse disorders. With the identification of the selective CB1R antagonist, rimonabant, in 1994, and subsequently of other CB1R antagonists, there has been a rapid expansion of research investigating their ability to modulate the effects of the drugs of abuse. This review highlights some of the preclinical and clinical studies that have examined the effects of CB1R antagonists under conditions potentially predictive of their therapeutic efficacy as treatments for drug abuse disorders.”
Cannabis has been used throughout human history. Delta (9)-tetrahydrocannabinol (THC) is the primary psychoactive component of cannabis. THC metabolises to 11-OH-THC and further to THC-acid, which is an inactive metabolite. We present an overview of the pharmacokinetics and pharmacodynamics of cannabinoids.
This article is based on selected literature with an emphasis on the pharmacodynamics of cannabinoids.
It has been demonstrated that mammalian tissues express cannabinoid receptors (CB1, CB2 and most probably CB3) and endogenous ligands for these. Knowledge of these receptors has lead to the development of components that stimulate (CB-agonists) or block their function (CB-antagonists). This opens up for the study of any potential therapeutic effects of cannabinoids. Research on a possible therapeutic potential of cannabinoids should however not overshadow the well-documented negative effects of cannabis; i.e. impaired cognitive functions, intoxication and an increased risk for development of psychosis and psychotic symptoms.”
“There are at least two types of cannabinoid receptors, CB(1) and CB(2), both coupled to G proteins. CB(1) receptors exist primarily on central and peripheral neurons, one of their functions being to modulate neurotransmitter release. CB(2) receptors are present mainly on immune cells. Their roles are proving more difficult to establish but seem to include the modulation of cytokine release. Endogenous agonists for cannabinoid receptors (endocannabinoids) have also been discovered, the most important being arachidonoyl ethanolamide (anandamide), 2-arachidonoyl glycerol and 2-arachidonyl glyceryl ether. Other endocannabinoids and cannabinoid receptor types may also exist. Although anandamide can act through CB(1) and CB(2) receptors, it is also a vanilloid receptor agonist and some of its metabolites may possess yet other important modes of action. The discovery of the system of cannabinoid receptors and endocannabinoids that constitutes the “endocannabinoid system” has prompted the development of CB(1)- and CB(2)-selective agonists and antagonists/inverse agonists. CB(1)/CB(2) agonists are already used clinically, as anti-emetics or to stimulate appetite. Potential therapeutic uses of cannabinoid receptor agonists include the management of multiple sclerosis/spinal cord injury, pain, inflammatory disorders, glaucoma, bronchial asthma, vasodilation that accompanies advanced cirrhosis, and cancer. Following their release onto cannabinoid receptors, endocannabinoids are removed from the extracellular space by membrane transport and then degraded by intracellular enzymic hydrolysis. Inhibitors of both these processes have been developed. Such inhibitors have therapeutic potential as animal data suggest that released endocannabinoids mediate reductions both in inflammatory pain and in the spasticity and tremor of multiple sclerosis. So too have CB(1) receptor antagonists, for example for the suppression of appetite and the management of cognitive dysfunction or schizophrenia.”
“The endocannabinoid system has been recently recognized as an important modulatory system in the function of brain, endocrine, and immune tissues. It appears to play a very important regulatory role in the secretion of hormones related to reproductive functions and response to stress. The important elements of this system are: endocannabinoid receptors (types CB1 and CB2), their endogenous ligands (N-arachidonoylethanolamide, 2-arachidonoyl glycerol), enzymes involved in their synthesis and degradation, as well as cannabinoid antagonists. In humans this system also controls energy homeostasis and mainly influences the function of the food intake centers of the central nervous system and gastrointestinal tract activity. The endocannabinoid system regulates not only the central and peripheral mechanisms of food intake, but also lipids synthesis and turnover in the liver and adipose tissue as well as glucose metabolism in muscle cells. Rimonabant, a new and selective central and peripheral cannabinoid-1 receptor (CB1) blocker, has been shown to reduce body weight and improve cardiovascular risk factor (metabolic syndrome) in obese patients by increasing HDL-cholesterol and adiponectin blood levels as well as decreasing LDL-cholesterol, leptin, and C-reactive protein (a proinflammatory marker) concentrations. It is therefore possible to speculate about a future clinical use of CB1 antagonists, as a means of improving gonadotrophin pulsatility and fertilization capacity as well as the prevention of cardiovasculary disease and type 2 diabetes mellitus. Drugs acting as agonists of CB1 receptors (Dronabinol, Dexanabinol) are currently proposed for evaluation as drugs to treat neurodegenerative disorders (Alzheimer’s and Parkinson’s diseases), epilepsy, anxiety, and stroke.”
Cannabinoids bind to cannabinoid receptors CB(1) and CB(2) and have been reported to possess anti-tumorigenic activity in various cancers. However, the mechanisms through which cannabinoids modulate tumor growth are not well known. In this study, we report that a synthetic non-psychoactive cannabinoid that specifically binds to cannabinoid receptor CB(2) may modulate breast tumor growth and metastasis by inhibiting signaling of the chemokine receptor CXCR4 and its ligand CXCL12. This signaling pathway has been shown to play an important role in regulating breast cancer progression and metastasis.
This study provides novel insights into the crosstalk between CB(2) and CXCR4/CXCL12-signaling pathways in the modulation of breast tumor growth and metastasis. Furthermore, these studies indicate that CB(2) receptors could be used for developing innovative therapeutic strategies against breast cancer.”