Category Archives: Liver Disease

Cannabinoids inhibit fibrogenesis in diffuse systemic sclerosis fibroblasts.

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Rheumatology

“Recently, it has also been demonstrated that the pleiotropic cannabinoid system is involved in both liver and pancreatic fibrosis. Furthermore, cannabinoids may play a pro- or anti-fibrogenic role depending on their interaction with CB1r or CB2r.

This raises the possibility that pharmacologic modulation of the endocannabinoid system could be a target to limit tissue damage in pathologic fibrosis.

It has been demonstrated that the endocannabinoid system is up-regulated in pathologic fibrosis and that modulation of the cannabinoid receptors might limit the progression of uncontrolled fibrogenesis.

Both CB1 and CB2 receptors were over-expressed in dcSSc fibroblasts compared with healthy controls.

Our preliminary findings suggest that cannabinoids are provided with an anti-fibrotic activity, thereby possibly representing a new class of agents targeting fibrosis diseases.”

http://rheumatology.oxfordjournals.org/content/48/9/1050.long

Fatty Acid Binding Protein-1 (FABP1) and the Human FABP1 T94A Variant: Roles in the Endocannabinoid System and Dyslipidemias.

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“The first discovered member of the mammalian FABP family, liver fatty acid binding protein (FABP1, L-FABP), occurs at high cytosolic concentration in liver, intestine, and in the case of humans also in kidney.

While the rat FABP1 is well studied, the extent these findings translate to human FABP1 is not clear-especially in view of recent studies showing that endocannabinoids and cannabinoids represent novel rat FABP1 ligands and FABP1 gene ablation impacts the hepatic endocannabinoid system, known to be involved in non-alcoholic fatty liver (NAFLD) development.

Although not detectable in brain, FABP1 ablation nevertheless also impacts brain endocannabinoids. Despite overall tertiary structure similarity, human FABP1 differs significantly from rat FABP1 in secondary structure, much larger ligand binding cavity, and affinities/specificities for some ligands. Moreover, while both mouse and human FABP1 mediate ligand induction of peroxisome proliferator activated receptor-α (PPARα), they differ markedly in pattern of genes induced.

This is critically important because a highly prevalent human single nucleotide polymorphism (SNP) (26-38 % minor allele frequency and 8.3 ± 1.9 % homozygous) results in a FABP1 T94A substitution that further accentuates these species differences. The human FABP1 T94A variant is associated with altered body mass index (BMI), clinical dyslipidemias (elevated plasma triglycerides and LDL cholesterol), atherothrombotic cerebral infarction, and non-alcoholic fatty liver disease (NAFLD).

Resolving human FABP1 and the T94A variant’s impact on the endocannabinoid and cannabinoid system is an exciting challenge due to the importance of this system in hepatic lipid accumulation as well as behavior, pain, inflammation, and satiety.”

http://www.ncbi.nlm.nih.gov/pubmed/27117865

Endocannabinoids signaling: Molecular mechanisms of liver regulation and diseases.

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“The endocannabinoid system (ECS) includes endocannabinoids (eCBs), cannabinoid (CB) receptors and the enzymes that are responsible for endocannabinoid production and metabolism. The ECS has been reported to be present in both brain and peripheral tissues.

Recent studies have indicated that eCBs and their receptors are involved in the development of various liver diseases. They were found to be altered in response to many danger factors.

It is generally accepted that eCB may exert a protective action via CB2 receptors in different liver diseases. However, eCBs have also been demonstrated to have pathogenic role via their CB1 receptors.

Although the therapeutic potential of CB1 receptor blockade in liver diseases is limited by its neuropsychiatric side effects, many studies have been conducted to search for novel, peripherally restricted CB1 antagonists or CB2 agonists, which may minimize their neuropsychiatric side effects in clinical use.

This review summarizes the current understanding of the ECS in liver diseases and provides evidence for the potential to develop new therapeutic strategies for the treatment of these liver diseases.”

http://www.ncbi.nlm.nih.gov/pubmed/27100518

Discovery of KLS-13019, a Cannabidiol-Derived Neuroprotective Agent, with Improved Potency, Safety, and Permeability.

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“Cannabidiol is the nonpsychoactive natural component of C. sativa that has been shown to be neuroprotective in multiple animal models.

Our interest is to advance a therapeutic candidate for the orphan indication hepatic encephalopathy (HE). HE is a serious neurological disorder that occurs in patients with cirrhosis or liver failure.

Although cannabidiol is effective in models of HE, it has limitations in terms of safety and oral bioavailability.

Herein, we describe a series of side chain modified resorcinols that were designed for greater hydrophilicity and “drug likeness”, while varying hydrogen bond donors, acceptors, architecture, basicity, neutrality, acidity, and polar surface area within the pendent group.

Our primary screen evaluated the ability of the test agents to prevent damage to hippocampal neurons induced by ammonium acetate and ethanol at clinically relevant concentrations.

Notably, KLS-13019 was 50-fold more potent and >400-fold safer than cannabidiol and exhibited an in vitro profile consistent with improved oral bioavailability.”

http://www.ncbi.nlm.nih.gov/pubmed/27096053

ENDOCANNABINOID SYSTEM: A multi-facet therapeutic target.

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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

Immunohistochemical analysis of cannabinoid receptor 1 expression in steatotic rat livers.

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“The primary aim of the present study was to determine the expression levels of cannabinoid receptor type 1 (CB1) in steatotic rat livers.  The secondary aim was to clarify whether steatosis and inflammation are more marked in areas with increased CB1 overexpression.

The expression of CB1 and the number of cells overexpressing CB1 were determined. Steatosis was scored according to the Dixon scoring system.

CB1 overexpression and steatosis were detected in hepatocytes from all 38 livers sampled. The expression of CB1 was more marked in hepatocytes localized next to portal triads. Near the central veins, the expression was significantly weaker. Steatosis was more marked in areas of increased CB1 overexpression. Lymphocyte infiltration was more commonly observed in areas of increased CB1 overexpression.

Therefore, the present results indicate that CB1 receptors are overexpressed in areas with steatosis, and indicate that CB1 in hepatocytes contributes to the formation of steatosis in rats, even prior to its progression to steatohepatitis.

These results are consistent with publications reporting that CB1 in hepatocytes increases lipogenesis and contributes to inflammation.”

http://www.ncbi.nlm.nih.gov/pubmed/27073427

http://www.thctotalhealthcare.com/category/liver-disease/

Exogenous hepatitis B virus envelope proteins induce endoplasmic reticulum stress: involvement of cannabinoid axis in liver cancer cells.

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“HBV represents the most common chronic viral infection and major cause of hepatocellular carcinoma (HCC), although its exact role in liver tumorigenesis is unclear. Massive storage of the small (SHBs), middle (MHBs) and large surface (LHBs) HBV envelope proteins leads to cell stress and sustained inflammatory responses. Cannabinoid (CB) system is involved in the pathogenesis of liver diseases, stimulating acute and chronic inflammation, liver damage and fibrogenesis; it triggers endoplasmic reticulum (ER) stress response. The aim of our work was to investigate the activation of ER stress pathway after ectopic HBV envelope proteins expression, in liver cancer cells, and the role exerted by CB receptors. PCR, immunofluorescence and western blotting showed that exogenous LHBs and MHBs induce a clear ER stress response in Huh-7 cells expressing CB1 receptor. Up-regulation of the chaperone BiP/GRP78 (Binding Immunoglobulin Protein/Glucose-Regulated Protein 78) and of the transcription factor CHOP/GADD153 (C/EBP Homologous Protein/Growth Arrest and DNA Damage inducible gene 153), phosphorylation of PERK (PKR-like ER Kinase) and eIF2α (Eukaryotic Initiation Factor 2α) and splicing of XBP1 (X-box binding protein 1) was observed. CB1-/- HepG2 cells did not show any ER stress activation. Inhibition of CB1 receptor counteracted BiP expression in transfected Huh-7 and in HBV+ PLC/PRF/5 cells; whereas no effect was observed in HBV- HLF cells. These results suggest that HBV envelope proteins are able to induce the ER stress pathway. CB1 expression is directly correlated with ER stress function. Further investigations are needed to clarify the involvement of cannabinoid in HCC progression after HBV infection.”

http://www.ncbi.nlm.nih.gov/pubmed/26967385

Cannabinoid receptors are involved in the protective effect of a novel curcumin derivative C66 against CCl4-induced liver fibrosis.

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“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.”

http://www.ncbi.nlm.nih.gov/pubmed/26945822

Cannabinoid receptor signaling regulates liver development and metabolism.

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“Endocannabinoid (EC) signaling mediates psychotropic effects and regulates appetite.

By contrast, potential roles in organ development and embryonic energy consumption remain unknown. Here, we demonstrate that genetic or chemical inhibition of cannabinoid receptor (Cnr) activity disrupts liver development and metabolic function in zebrafish (Danio rerio), impacting hepatic differentiation, but not endodermal specification: loss of cannabinoid receptor 1 (cnr1) and cnr2 activity leads to smaller livers with fewer hepatocytes, reduced liver-specific gene expression and proliferation.

Our work describes a novel developmental role for EC signaling, whereby Cnr-mediated regulation of Srebfs and methionine metabolism impacts liver development and function.”

http://www.ncbi.nlm.nih.gov/pubmed/26884397

Endocannabinoid System Contributes to Liver Injury and Inflammation by Activation of Bone Marrow-Derived Monocytes/Macrophages in a CB1-Dependent Manner.

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“Hepatic injury undergoes significant increases in endocannabinoids and infiltrations of macrophages, yet the concrete mechanisms of changes in endocannabinoids and the functions of macrophage-expressed cannabinoid receptors (CBs) are unclear…

In the chimeric murine model, we found that blockade of CB1 by administration of a CB1 antagonist inhibited the recruitment of Bone marrow-derived monocytes/macrophages (BMM) into injured liver using immunofluorescence staining and FACS, but it did not have effects on migration of T cells and dendritic cells without CB1 expression. Furthermore, activation of CB1 enhanced cytokine expression of BMM. In vivo, inhibition of CB1 attenuated the inflammatory cytokine level through real-time RT-PCR and cytometric bead array, ameliorating hepatic inflammation and fibrosis.

In this study, we identify inactivation of BMM-expressed CB1 as a therapeutic strategy for reducing hepatic inflammation and fibrosis.”

http://www.ncbi.nlm.nih.gov/pubmed/26320250