“The endogenous cannabinoid system has been characterized in some female reproductive organs but little is known about the expression and localization pattern of cannabinoid-degrading enzymes in relation to the CB1 cannabinoid receptor in human oocytes. In this study, we focus on the investigation of the presence and differential distribution of fatty acid amide hydrolase (FAAH) and monoglyceride lipase (MGLL) in relation to CB1 during the maturation of human oocytes. We used a total of 290 human oocytes not suitable for in vitro fertilization/intracytoplasmic sperm injection (ICSI): germinal-vesicle (GV) and metaphase-I (MI) stages and metaphase-II (MII) oocytes that had not developed into an embryo after ICSI.Cannabinoid-degrading enzymes and the cannabinoid CB1 receptor were present in human oocytes. Specifically, FAAH was detected in the periphery of the oocyte from the GV to MI stage and co-localized with CB1. Later, by the MII stage, FAAH was spread within the oocyte, whereas MGLL immunostaining was homogeneous across the oocyte at all stages of maturation and only overlapped with CB1 at the GV stage. This coordinated redistribution of cannabinoid system proteins suggests a role for this system in the maturation of the female gamete.”
Category Archives: Endocannabinoid System
Cannabinoid receptors are involved in the protective effect of a novel curcumin derivative C66 against CCl4-induced liver fibrosis.
“Liver fibrosis is one of the major causes of morbidity and mortality worldwide and lacks efficient therapy. Recent studies suggest the curcumin protects liver from fibrosis. However, curcumin itself is in low bioavailable concentration when administered orally, and the protective mechanism remains poorly understood. The current study aimed to investigate whether a more stable derivative of curcumin, C66, protects against CCl4-inudced liver fibrosis and examine the underlying mechanism involving cannabinoid receptor (CB receptor). At a dose lower than curcumin itself, C66 displayed a superior anti-fibrotic effect. C66 significantly reduced collagen deposition, pro-inflammatory cytokine expression, and liver enzyme activities. Mechanistic study revealed that C66 treatment decreased CCl4-induced cannabinoid receptor 1 (CB1 receptor) expression and increased cannabinoidreceptor 2 (CB2 receptor) expression, along with an inhibition of JNK/NF-κB-mediated inflammatory signaling. In conclusion, this curcumin derivative attenuates liver fibrosis likely involving a CB/JNK/NF-κB-mediated pathway.”
Nutritional n-3 PUFA Deficiency Abolishes Endocannabinoid Gating of Hippocampal Long-Term Potentiation.
“Maternal n-3 polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid, is critical during perinatal brain development. How early postnatal n-3 PUFA deficiency impacts on hippocampal synaptic plasticity is mostly unknown. Here we compared activity-dependent plasticity at excitatory and inhibitory synapses in the CA1 region of the hippocampus in weaned pups whose mothers were fed with an n-3 PUFA-balanced or n-3 PUFA-deficient diet. Normally, endogenous cannabinoids (eCB) produced by the post-synapse dually control network activity by mediating the long-term depression of inhibitory inputs (iLTD) and positively gating NMDAR-dependent long-term potentiation (LTP) of excitatory inputs. We found that both iLTD and LTP were impaired in n-3 PUFA-deficient mice. Pharmacological dissection of the underlying mechanism revealed that impairment of NMDAR-dependent LTP was causally linked to and attributable to the ablation of eCB-mediated iLTD and associated to disinhibitory gating of excitatory synapses. The data shed new light on how n-3 PUFAs shape synaptic activity in the hippocampus and provide a new synaptic substrate to the cognitive impairments associated with perinatal n-3 deficiency.”
An Increase in the Omega-6/Omega-3 Fatty Acid Ratio Increases the Risk for Obesity.
“In the past three decades, total fat and saturated fat intake as a percentage of total calories has continuously decreased in Western diets, while the intake of omega-6 fatty acid increased and the omega-3 fatty acid decreased, resulting in a large increase in the omega-6/omega-3 ratio from 1:1 during evolution to 20:1 today or even higher.
This change in the composition of fatty acids parallels a significant increase in the prevalence of overweight and obesity.
Experimental studies have suggested that omega-6 and omega-3 fatty acids elicit divergent effects on body fat gain through mechanisms of adipogenesis, browning of adipose tissue, lipid homeostasis, brain-gut-adipose tissue axis, and most importantly systemic inflammation.
Prospective studies clearly show an increase in the risk of obesity as the level of omega-6 fatty acids and the omega-6/omega-3 ratio increase in red blood cell (RBC) membrane phospholipids, whereas high omega-3 RBC membrane phospholipids decrease the risk of obesity.
Recent studies in humans show that in addition to absolute amounts of omega-6 and omega-3 fatty acid intake, the omega-6/omega-3 ratio plays an important role in increasing the development of obesity via both AA eicosanoid metabolites and hyperactivity of the cannabinoid system, which can be reversed with increased intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
A balanced omega-6/omega-3 ratio is important for health and in the prevention and management of obesity.”
Effects of cannabinoid receptor activation by CP55,940 on normal bladder function and irritation-induced bladder overactivity in non-awake anaesthetised rats.
“CP55,940 is a synthetic analogue of tetrahydrocannabidiol, which is a psychoactive ingredient of the Cannabis plant.
This study was designed to evaluate the effects of CP55,940 on normal bladder function in vivo and examine whether it suppresses urinary frequency induced by nociceptive stimuli in the bladder.
CP55,940 decreases bladder activity and urinary frequency induced by nociceptive stimuli, probably by suppression of bladder afferent activity. Effects of CP55,940 were abolished by both CBR antagonists. This data implicates a role for the endocannabinoid system in bladder mechanoafferent function in rats. In addition, our results show that CP55,940 reverses urinary frequency exemplified in an overactive bladder model, suggesting it could be an effective treatment for patients with lower urinary tract symptoms.”
Role of cannabinoids in gastrointestinal mucosal defense and inflammation.
“Modulating the activity of the endocannabinoid system influences various gastrointestinal physiological and pathophysiological processes, and cannabinoid receptors as well as regulatory enzymes responsible for the synthesis or degradation of endocannabinoids represent potential targets to reduce the development of gastrointestinal mucosal lesions, hemorrhage and inflammation.
Direct activation of CB1 receptors by plant-derived, endogenous or synthetic cannabinoids effectively reduces both gastric acid secretion and gastric motor activity, and decreases the formation of gastric mucosal lesions induced by stress, pylorus ligation, nonsteroidal anti-inflammatory drugs (NSAIDs) or alcohol, partly by peripheral, partly by central mechanisms.
Similarly, indirect activation of cannabinoid receptors through elevation of endocannabinoid levels by globally acting or peripherally restricted inhibitors of their metabolizing enzymes (FAAH, MAGL) or by inhibitors of their cellular uptake reduced the gastric mucosal lesions induced by NSAIDs in a CB1 receptor-dependent fashion.
Dual inhibition of FAAH and cyclooxygenase induced protection against both NSAID-induced gastrointestinal damage and intestinal inflammation.
Moreover, in intestinal inflammation direct or indirect activation of CB1 and CB2 receptors exerts also multiple beneficial effects.
Namely, activation of both CB receptors was shown to ameliorate intestinal inflammation in various murine colitis models, to decrease visceral hypersensitivity and abdominal pain, as well as to reduce colitis-associated hypermotility and diarrhea.
In addition, CB1 receptors suppress secretory processes and also modulate intestinal epithelial barrier functions. Thus, experimental data suggest that the endocannabinoid system represents a promising target in the treatment of inflammatory bowel diseases, and this assumption is also confirmed by preliminary clinical studies.”
Cannabinoid CB2 receptors are involved in the regulation of fibrogenesis during skin wound repair in mice.
“Studies have shown that cannabinoid CB2 receptors are involved in wound repair, however, its physiological roles in fibrogenesis remain to be elucidated.
In the present study, the capacity of cannabinoid CB2 receptors in the regulation of skin fibrogenesis during skin wound healing was investigated.
These results indicated that cannabinoid CB2 receptors modulate fibrogenesis and the TGF‑β/Smad profibrotic signaling pathway during skin wound repair in the mouse.”
Cannabinoids: Medical implications.
“Herbal cannabis has been used for thousands of years for medical purposes.
With elucidation of the chemical structures of tetrahydrocannabinol (THC) and cannabidiol (CBD) and with discovery of the human endocannabinoid system, the medical usefulness of cannabinoids has been more intensively explored.
While more randomized clinical trials are needed for some medical conditions, other medical disorders, like chronic cancer and neuropathic pain and certain symptoms of multiple sclerosis, have substantial evidence supporting cannabinoid efficacy.
While herbal cannabis has not met rigorous FDA standards for medical approval, specific well-characterized cannabinoids have met those standards.
Where medical cannabis is legal, patients typically see a physician who “certifies” that a benefit may result.
Physicians must consider important patient selection criteria such as failure of standard medical treatment for a debilitating medical disorder. Medical cannabis patients must be informed about potential adverse effects, such as acute impairment of memory, coordination and judgment, and possible chronic effects, such as cannabis use disorder, cognitive impairment, and chronic bronchitis.
Novel ways to manipulate the endocannbinoid system are being explored to maximize benefits of cannabinoid therapy and lessen possible harmful effects.
Key messages The medical disorders with the current best evidence that supports a benefit for cannabinoid use are the following: multiple sclerosis patient-reported symptoms of spasticity (nabiximols, nabilone, dronabinol, and oral cannabis extract), multiple sclerosis central pain or painful spasms (nabiximols, nabilone, dronabinol, and oral cannabis extract), multiple sclerosis bladder frequency (nabiximols), and chronic cancer pain/neuropathic pain (nabiximols and smoked THC).
Participating physicians should be knowledgeable about cannabinoids, closely look at the risk/benefit ratio, and consider certain important criteria in selecting a patient, such as: age, severity, and nature of the medical disorder, prior or current serious psychiatric or substance use disorder, failure of standard medical therapy as well as failure of an approved cannabinoid, serious underlying cardiac/pulmonary disease, agreement to follow-up visits, and acceptance of the detailed explanation of potential adverse risks.
The normal human endocannabinoid system is important in the understanding of such issues as normal physiology, cannabis use disorder, and the development of medications that may act as agonists or antagonists to CB1 and CB2.
By understanding the endocannabinoid system, it may be possible to enhance the beneficial effects of cannabinoid-related medication, while reducing the harmful effects.”
Study the Effect of Endocannabinoid System on Rat Behavior in Elevated Plus-Maze.
“Previous studies have shown that cannabinoidergic system is involved in anxiety.
The aim of this study is to evaluate the effect of pharmacological stimulation or blocking of CB1 receptors and inhibition of endocannabinoid degradation in anxiety like behavior in elevated plus-maze (EPM) test in rat.
It is concluded that activation of cannabinoid receptor exert anxiolytic effect while blocking of cannabinoid receptor resulted in anxiety behavior. The locomotor activity was not significantly changed by cannabinoid system.
It is suggested that potentiation of cannabinoid system may be therapeutic strategy for the anxiety behavior.”
Stimulation of cannabinoid CB1 receptors prevents nerve-mediated airway hyperreactivity in NGF-induced inflammation in mouse airways.
“In the present study, we tested the hypothesis that cannabinoids have both acute and chronic modulatory effects on nerve-mediated contractions in NGF-induced airway inflammation.
This study shows that stimulation of cannabinoid CB1 receptors modifies the increase of neuronal activity and density in NGF-induced airway inflammation and directly inhibits cholinergic contractions in the airways by a presynaptic mechanism.
These findings indicate a protective role of CB1 receptors in airway inflammation.”