Modulation of cellular redox homeostasis by the endocannabinoid system

“The endocannabinoid system (ECS) and reactive oxygen species (ROS) constitute two key cellular signalling systems that participate in the modulation of diverse cellular functions.

Importantly, growing evidence suggests that cross-talk between these two prominent signalling systems acts to modulate functionality of the ECS as well as redox homeostasis in different cell types…

To conclude, there is growing appreciation that the ECS may play an important role in the regulation of cellular redox homeostasis…

Indeed, the studies highlighted in this review show that ECS function can impact upon free radical production in a number of different ways.

Crucially, given the importance of redox status in the development of numerous pathologies, these findings identify ECS components as potential therapeutic targets for the treatment of oxidative stress-related neurological, cardiovascular and metabolic disorders.”

http://rsob.royalsocietypublishing.org/content/6/4/150276

ENDOCANNABINOID SYSTEM: A multi-facet therapeutic target.

Image result for Curr Clin Pharmacol.

“Cannabis sativa is also popularly known as marijuana. It is being cultivated and used by man for recreational and medicinal purposes from many centuries.

Study of cannabinoids was at bay for very long time and its therapeutic value could not be adequately harnessed due to its legal status as proscribed drug in most of the countries.

The research of drugs acting on endocannabinoid system has seen many ups and down in recent past. Presently, it is known that endocannabinoids has role in pathology of many disorders and they also serve “protective role” in many medical conditions.

Several diseases like emesis, pain, inflammation, multiple sclerosis, anorexia, epilepsy, glaucoma, schizophrenia, cardiovascular disorders, cancer, obesity, metabolic syndrome related diseases, Parkinson’s disease, Huntington’s disease, Alzheimer’s disease and Tourette’s syndrome could possibly be treated by drugs modulating endocannabinoid system.

Presently, cannabinoid receptor agonists like nabilone and dronabinol are used for reducing the chemotherapy induced vomiting. Sativex (cannabidiol and THC combination) is approved in the UK, Spain and New Zealand to treat spasticity due to multiple sclerosis. In US it is under investigation for cancer pain, another drug Epidiolex (cannabidiol) is also under investigation in US for childhood seizures. Rimonabant, CB1 receptor antagonist appeared as a promising anti-obesity drug during clinical trials but it also exhibited remarkable psychiatric side effect profile. Due to which the US Food and Drug Administration did not approve Rimonabant in US. It sale was also suspended across the EU in 2008.

Recent discontinuation of clinical trial related to FAAH inhibitor due to occurrence of serious adverse events in the participating subjects could be discouraging for the research fraternity. Despite of some mishaps in clinical trials related to drugs acting on endocannabinoid system, still lot of research is being carried out to explore and establish the therapeutic targets for both cannabinoid receptor agonists and antagonists.

One challenge is to develop drugs that target only cannabinoid receptors in a particular tissue and another is to invent drugs that acts selectively on cannabinoid receptors located outside the blood brain barrier. Besides this, development of the suitable dosage forms with maximum efficacy and minimum adverse effects is also warranted.

Another angle to be introspected for therapeutic abilities of this group of drugs is non-CB1 and non-CB2 receptor targets for cannabinoids.

In order to successfully exploit the therapeutic potential of endocannabinoid system, it is imperative to further characterize the endocannabinoid system in terms of identification of the exact cellular location of cannabinoid receptors and their role as “protective” and “disease inducing substance”, time-dependent changes in the expression of cannabinoid receptors.”

http://www.ncbi.nlm.nih.gov/pubmed/27086601

Cannabidiol promotes browning in 3T3-L1 adipocytes.

“Recruitment of the brown-like phenotype in white adipocytes (browning) and activation of existing brown adipocytes are currently being investigated as a means to combat obesity.

The present study was designed to investigate the effects of cannabidiol (CBD), a major nonpsychotropic phytocannabinoid of Cannabis sativa, on induction of browning in 3T3-L1 adipocytes.

These data suggest possible roles for CBD in browning of white adipocytes, augmentation of lipolysis, thermogenesis, and reduction of lipogenesis.

In conclusion, the current data suggest that CBD plays dual modulatory roles in the form of inducing the brown-like phenotype as well as promoting lipid metabolism.

Thus, CBD may be explored as a potentially promising therapeutic agent for the prevention of obesity.”

http://www.ncbi.nlm.nih.gov/pubmed/27067870

http://www.thctotalhealthcare.com/category/obesity-2/

Orexin-A represses satiety-inducing POMC neurons and contributes to obesity via stimulation of endocannabinoid signaling.

“In the hypothalamic arcuate nucleus (ARC), proopiomelanocortin (POMC) neurons and the POMC-derived peptide α-melanocyte-stimulating hormone (α-MSH) promote satiety. POMC neurons receive orexin-A (OX-A)-expressing inputs and express both OX-A receptor type 1 (OX-1R) and cannabinoid receptor type 1 (CB1R) on the plasma membrane.

OX-A is crucial for the control of wakefulness and energy homeostasis and promotes, in OX-1R-expressing cells, the biosynthesis of the endogenous counterpart of marijuana’s psychotropic and appetite-inducing component Δ9-tetrahydrocannabinol, i.e., the endocannabinoid 2-arachidonoylglycerol (2-AG), which acts at CB1R.

We report that OX-A/OX-1R signaling at POMC neurons promotes 2-AG biosynthesis, hyperphagia, and weight gain by blunting α-MSH production via CB1R-induced and extracellular-signal-regulated kinase 1/2 activation- and STAT3 inhibition-mediated suppression ofPomcgene transcription. Because the systemic pharmacological blockade of OX-1R by SB334867 caused anorectic effects by reducing food intake and body weight, our results unravel a previously unsuspected role for OX-A in endocannabinoid-mediated promotion of appetite by combining OX-induced alertness with food seeking. Notably, increased OX-A trafficking was found in the fibers projecting to the ARC of obese mice (ob/oband high-fat diet fed) concurrently with elevation of OX-A release in the cerebrospinal fluid and blood of mice.

Furthermore, a negative correlation between OX-A and α-MSH serum levels was found in obese mice as well as in human obese subjects (body mass index > 40), in combination with elevation of alanine aminotransferase and γ-glutamyl transferase, two markers of fatty liver disease.

These alterations were counteracted by antagonism of OX-1R, thus providing the basis for a therapeutic treatment of these diseases.”

http://www.ncbi.nlm.nih.gov/pubmed/27071101

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.”

http://www.ncbi.nlm.nih.gov/pubmed/26950145

The endocannabinoid system: novel pathway for cardiometabolic Risk-factor reduction.

“Although rimonabant has been approved for use in several countries, the Food and Drug Administration has expressed concern about the potential for adverse neurologic and psychiatric effects, considering the widespread distribution of CB1 receptors in the brain. While more research is clearly needed, the clinical evidence shows that CB1-receptor blockade with rimonabant improves multiple cardiovascular and metabolic variables, including body weight and waist circumference, HDL-C, triglycerides, and glucose metabolism. Furthermore, these effects, which are probably mediated by both peripheral and central actions in the ECS, appear to be greater than the improvements that would be expected from weight loss alone. There are multiple ongoing and planned studies with rimonabant as well as several other CB-receptor blockers (e.g., taranabant, CP-945,598). While diet and exercise are the cornerstones of cardiometabolic risk-factor reduction, improved pharmacotherapies are urgently needed. The ECS has provided us with new insights and a promising new avenue for the management of obesity and its associated cardiometabolic risk factors.”

http://www.ncbi.nlm.nih.gov/pubmed/18047036

The endocannabinoid system: potential for reducing cardiometabolic risk.

“The endocannabinoid system (ECS) affects multiple metabolic pathways in the brain and other organs. The transmembrane CB receptors were cloned in the early 1990s, followed shortly thereafter by the discovery of endogenous ligands, now known as endocannabinoids.

Three general types of cannabimimetic compounds have been described: herbal CBs, which occur uniquely in the cannabis plant (Cannabis sativa); endogenous CBs (or endocannabinoids), which are produced in the brain and peripheral tissues; and synthetic CBs, which are functionally similar compounds synthesized in the laboratory.

Obesity is associated with increased risk for insulin resistance, type 2 diabetes, nonalcoholic fatty liver disease, atherogenic dyslipidemia, and cardiovascular disease. Recent studies indicate that the body protects itself from weight loss by lowering energy expenditure. Both energy consumption and energy expenditure are regulated by hormones from a number of organs that act on the brain, as well as neural signals emanating from the brain itself.

Lifestyle modification is the initial intervention for obesity, with emphasis on reducing calorie intake and increasing physical activity; pharmacotherapy may be indicated for certain cardiovascular and metabolic risk factors.

This review focuses on the link between the biology of the cannabinoid receptor type 1 (CB1 receptor) system and body-weight regulation, as well as clinical data from studies of the first CB1 receptor antagonist…”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2905146/

The endocannabinoid system: a new approach to control cardiovascular disease.

“The endocannabinoid (EC) system consists of 2 types of G-protein-coupled cannabinoid receptors–cannabinoid type 1 (CB1) and cannabinoid type 2 (CB2)–and their natural ligands.

The EC system plays a key role in the regulation of food intake and fat accumulation, as well as glucose and lipid metabolism.

When overactivated, the EC system triggers dyslipidemia, thrombotic and inflammatory states, and insulin resistance.

Blocking CB1 receptors centrally and peripherally in adipose tissue can help normalize an overactivated EC system. CB1 blockade helps regulate food intake and adipose tissue metabolism, contributing to improved insulin sensitivity and other features of the metabolic syndrome.

Visceral adipose tissue is most closely associated with the metabolic syndrome, which is a constellation of conditions that place people at high risk for coronary artery disease.

Targeting the EC system represents a new approach to treating visceral obesity and reducing cardiovascular risk factors.”

Vaccenic acid suppresses intestinal inflammation by increasing the endocannabinoid anandamide and non-cannabinoid signaling molecules in a rat model of the metabolic syndrome.

“Vaccenic acid (VA), the predominant ruminant-derived trans fat in the food chain, ameliorates hyperlipidemia yet mechanisms remain elusive. We investigated whether VA could influence tissue endocannabinoids (EC) by altering the availability of their biosynthetic precursor, arachidonic acid (AA) in membrane phospholipids (PL).

Interestingly, VA increased jejunal concentrations of anandamide and those of the non-cannabinoid signaling molecules, oleoylethanolamide and palmitoylethanolamide, relative to CD (P<0.05). This was consistent with a lower jejunal protein abundance (but not activity) of their degrading enzyme, fatty acid amide hydrolase and mRNA expression TNFα and IL-1β (P<0.05).

The ability of VA to reduce 2-AG in the liver and VAT provides a potential mechanistic explanation to alleviate ectopic lipid accumulation. The opposing regulation of EC and other non-cannabinoid lipid signaling molecules by VA suggests an activation of benefit via the EC system in the intestine.”

http://www.ncbi.nlm.nih.gov/pubmed/26891736

Effects of chronic exercise on the endocannabinoid system in Wistar rats with high-fat diet-induced obesity.

“The endocannabinoid system is dysregulated during obesity in tissues involved in the control of food intake and energy metabolism.

We examined the effect of chronic exercise on the tissue levels of endocannabinoids (eCBs) and on the expression of genes coding for cannabinoid receptor 1 (CB1) and cannabinoid receptor 2 (CB2) (Cnr1 and Cnr2, respectively) in the subcutaneous (SAT) and visceral adipose tissues and in the soleus and extensor digitorim longus (EDL) muscles, in rats fed with standard or high-fat diet…

The levels of eCBs and Cnr1 expression are altered in a tissue-specific manner following a high-fat diet, and chronic exercise reverses some of these alterations.”

http://www.ncbi.nlm.nih.gov/pubmed/26880264