Anti-inflammatory Properties of Cannabidiol, a Nonpsychotropic Cannabinoid, in Experimental Allergic Contact Dermatitis.

Phytocannabinoids modulate inflammatory responses by regulating the production of cytokines in several experimental models of inflammation. Cannabinoid type-2 (CB2) receptor activation was shown to reduce the production of the monocyte chemotactic protein-2 (MCP-2) chemokine in polyinosinic-polycytidylic acid [poly-(I:C)]-stimulated human keratinocyte (HaCaT) cells, an in vitro model of allergic contact dermatitis (ACD). We investigated if nonpsychotropic cannabinoids, such as cannabidiol (CBD), produced similar effects in this experimental model of ACD. HaCaT cells were stimulated with poly-(I:C), and the release of chemokines and cytokines was measured in the presence of CBD or other phytocannabinoids (such as cannabidiol acid, cannabidivarin, cannabidivarinic acid, cannabichromene, cannabigerol, cannabigerolic acid, cannabigevarin, tetrahydrocannabivarin, and tetrahydrocannabivarinic acid) and antagonists of CB1, CB2, or transient receptor potential vanilloid type-1 (TRPV1) receptors. HaCaT cell viability following phytocannabinoid treatment was also measured. The cellular levels of endocannabinoids [anandamide (AEA), 2-arachidonoylglycerol] and related molecules (palmitoylethanolamide, oleoylethanolamide) were quantified in poly-(I:C)-stimulated HaCaT cells treated with CBD. We show that in poly-(I:C)-stimulated HaCaT cells, CBD elevates the levels of AEA and dose-dependently inhibits poly-(I:C)-induced release of MCP-2, interleukin-6 (IL-6), IL-8, and tumor necrosis factor-α in a manner reversed by CB2 and TRPV1 antagonists 6-iodopravadoline (AM630) and 5'-iodio-resiniferatoxin (I-RTX), respectively, with no cytotoxic effect. This is the first demonstration of the anti-inflammatory properties of CBD in an experimental model of ACD.

Palmitoylethanolamide Exerts Antiproliferative Effect and Downregulates VEGF Signaling in Caco-2 Human Colon Carcinoma Cell Line Through a Selective PPAR-α-Dependent Inhibition of Akt/mTOR Pathway.

Palmitoylethanolamide (PEA) is a nutraceutical compound that has been demonstrated to improve intestinal inflammation. We aimed at evaluating its antiproliferative and antiangiogenic effects in human colon adenocarcinoma Caco-2 cell line. Caco-2 cells were treated with increasing concentrations of PEA (0.001, 0.01 and 0.1 µM) in the presence of peroxisome proliferator-activated receptor-a (PPAR-α) or PPAR-γ antagonists. Cell proliferation was evaluated by performing a MTT assay. Vascular endothelial growth factor (VEGF) release was estimated by ELISA, while the expression of VEGF receptor and the activation of the Akt/mammalian target of rapamycin (mTOR) pathway were evaluated by western blot analysis. PEA caused a significant and concentration-dependent decrease of Caco-2 cell proliferation at 48 h. PEA administration significantly reduced in a concentration-dependent manner VEGF secretion and VEGF receptor expression. Inhibition of Akt phosphorylation and a downstream decrease of phospho-mTOR and of p-p70S6K were observed as compared with untreated cells. PPAR-α, but not PPAR-γ antagonist, reverted all effects of PEA. PEA is able to decrease cell proliferation and angiogenesis. The antiangiogenic effect of PEA depends on the specific inhibition of the AkT/mTOR axis, through the activation of PPAR-α pathway. If supported by in vivo models, our data pave the way to PEA co-administration to the current chemotherapeutic regimens for colon carcinoma. Copyright © 2016 John Wiley & Sons, Ltd.

Cannabidiol in inflammatory bowel diseases: a brief overview.

This minireview highlights the importance of cannabidiol (CBD) as a promising drug for the therapy of inflammatory bowel diseases (IBD). Actual pharmacological treatments for IBD should be enlarged toward the search for low-toxicityand low-cost drugs that may be given alone or in combination with the conventional anti-IBD drugs to increase their efficacy in the therapy of relapsing forms of colitis. In the past, Cannabis preparations have been considered new promising pharmacological tools in view of their anti-inflammatory role in IBD as well as other gut disturbances. However, their use in the clinical therapy has been strongly limited by their psychotropic effects. CBD is a very promising compound since it shares the typical cannabinoid beneficial effects on gut lacking any psychotropic effects. For years, its activity has been enigmatic for gastroenterologists and pharmacologists, but now it is evident that this compound may interact at extra-cannabinoid system receptor sites, such as peroxisome proliferator-activated receptor-gamma. This strategic interaction makes CBD as a potential candidate for the development of a new class of anti-IBD drugs.

Palmitoylethanolamide counteracts reactive astrogliosis induced by ß-amyloid peptide.

Emerging evidence indicates that astrogliosis is involved in the pathogenesis of neurodegenerative disorders. Our previous findings suggested cannabinoids and Autacoid Local Injury Antagonism Amides (ALIAmides) attenuate glial response in models of neurodegeneration. The present study was aimed at exploring palmitoylethanolamide (PEA) ability to mitigate ß-amyloid (Aß)-induced astrogliosis. Experiments were carried out to investigate PEA's (10(-7) M) effects upon the expression and release of pro-inflammatory molecules in rat primary astrocytes activated by soluble Aß(1-42) (1 µg/ml) as well as to identify mechanisms responsible for such actions. The effects of Aß and exogenous PEA on the astrocyte levels of the endocannabinoidsand of endogenous ALIAmides were also studied. The peroxisome proliferator-activated receptor (PPAR)-α (MK886, 3 µM) or PPAR-γ (GW9662, 9 nM) antagonists were co-administered with PEA. Aß elevated endogenous PEA and d5-2-arachidonoylglycerol (2-AG) levels. Exogenous PEA blunted the Aß-induced expression of pro-inflammatory molecules. This effect was reduced by PPAR-α antagonist. Moreover, this ALIAmide, like Aß, increased 2-AG levels. These results indicate that PEA exhibits anti-inflammatory properties able to counteract Aß-induced astrogliosis, and suggest novel treatment for neuroinflammatory/ neurodegenerative processes.

Palmitoylethanolamide reduces granuloma-induced hyperalgesia by modulation of mast cell activation in rats.

The aim of this study was to obtain evidences of a possible analgesic role for palmitoylethanolamide (PEA) in chronic granulomatous inflammation sustained by mast cell (MC) activation in rats at 96 hours. PEA (200-400-800 µg/mL), locally administered at time 0, reduced in a concentration-dependent manner the expression and release of NGF in comparison with saline-treated controls. PEA prevented nerve formation and sprouting, as shown by histological analysis, reduced mechanical allodynia, evaluated by Von Frey filaments, and inhibited dorsal root ganglia activation. These results were supported by the evidence that MCs in granuloma were mainly degranulated and closely localized near nerve fibres and PEA significantly reduced MC degranulation and nerves fibre formation. These findings are the first evidence that PEA, by the modulation of MC activation, controls pain perception in an animal model of chronic inflammation, suggesting its potential use for the treatment of all those painful conditions in which MC activation is an initial key step.

Genomic and functional profiling of human Down syndrome neural progenitors implicates S100B and aquaporin 4 in cell injury.

Down syndrome (DS) is caused by trisomy of chromosome 21 and is characterized by mental retardation, seizures and premature Alzheimer's disease. To examine neuropathological mechanisms giving rise to this disorder, we generated multiple human DS neural progenitor cell (NPC) lines from the 19-21 week frontal cortex and characterized their genomic and functional properties. Microarray profiling of DS progenitors indicated that increased levels of gene expression were not limited to chromosome 21, suggesting that increased expression of genes on chromosome 21 altered transcriptional regulation of a subset of genes throughout the entire genome. Moreover, many transcriptionally dysregulated genes were involved in cell death and oxidative stress. Network analyses suggested that upregulated expression of chromosome 21 genes such as S100B and amyloid precursor protein activated the stress response kinase pathways, and furthermore, could be linked to upregulation of the water channel aquaporin 4 (AQP4). We further demonstrate in DS NPCs that S100B is constitutively overexpressed, that overexpression leads to increased reactive oxygen species (ROS) formation and activation of stress response kinases, and that activation of this pathway results in compensatory AQP4 expression. In addition, AQP4 expression could be induced by direct exposure to ROS, and siRNA inhibition of AQP4 resulted in elevated levels of ROS following S100B exposure. Finally, elevated levels of S100B-induced ROS and loss of AQP4 expression led to increased programmed cell death. These findings suggest that dysregulation of chromosome 21 genes in DS neural progenitors leads to increased ROS and thereby alters transcriptional regulation of cytoprotective, non-chromosome 21 genes in response to ongoing cellular insults.

Adelmidrol, a palmitoylethanolamide analogue, reduces chronic inflammation in a carrageenin-granuloma model in rats.

Palmitoylethanolamide (PEA) and some of its analogues have shown great efficacy in the treatment of pain and inflammation. Adelmidrol - the International Nonproprietary Name (INN) of the di-amide derivative of azelaic acid - is one of these analogues. The anti-inflammatory and analgesic effects of PEA and adelmidrol are hypothesized to be mediated, at least in part, by mast cell down-modulation. Mast cell mediators released at early stage of the inflammatory process drive the inflammatory reaction to chronicity as it happens in X-carrageenin-induced granulomatous tissue formation. In the present study, the choice of testing adelmidrol depends upon the physicochemical properties of the compound, i.e. the amphipatic feature, that make it more easily soluble than PEA. In this study, we investigated the effect of adelmidrol on granuloma formation induced by lambda-carrageenin-soaked sponge implant in rats. Our results show that the local administration of the compound under study significantly decreases weight and neo-angiogenesis in granulomatous tissue. The anti-inflammatory effect was due to the modulation of mast cells degranulation, as shown by histological analysis and by the inhibition of the release of several pro-inflammatory and pro-angiogenic enzymes (e.g. iNOS, chymase and metalloproteinase MMP-9), and mediators (e.g. nitric oxide and TNF-alpha). The results indicate that adelmidrol, given locally, may represent a potential therapeutic tool in controlling chronic inflammation.

Oligonucleotide decoy to NF-kappaB slowly released from PLGA microspheres reduces chronic inflammation in rat.

Nuclear factor-kappaB (NF-kappaB) plays a key role in the expression of several genes involved in the immune and inflammatory process. Previously, we demonstrated that NF-kappaB activation can be significantly inhibited by a double stranded oligodeoxynucleotide (ODN). Nevertheless, the therapeutic use of ODN requires a delivery system able to improve poor crossing of cell membranes and rapid in vivo enzymatic degradation. Poly(D,L-lactide-co-glycolide) (PLGA) microspheres can increase ODN stability in biological environment and release the encapsulated drug in long time frames. Here, we used a decoy ODN against NF-kappaB and we investigated its effect, when administered in naked form or when delivered by PLGA microspheres, in a rat model of chronic inflammation. The subcutaneous implant of lambda-carrageenin-soaked sponges caused leukocyte infiltration and formation of granulation tissue which were inhibited up to 15 days by co-injection of microspheres releasing decoy ODN whereas naked decoy ODN showed this effect only up to 5 days. Molecular analysis performed on granulation tissue demonstrated an inhibition of NF-kappaB activation correlated to a decrease of tumor necrosis factor-alpha (TNF-alpha) and inducible nitric oxide synthase (iNOS) expression. Our results suggest that microspheres could be an useful tool to improve pharmacokinetics of decoy ODN and may represent a strategy to inhibit NF-kappaB activation in chronic inflammation.

Cannabidiol in medicine: a review of its therapeutic potential in CNS disorders.

Cannabidiol (CBD) is the main non-psychotropic component of the glandular hairs of Cannabis sativa. It displays a plethora of actions including anticonvulsive, sedative, hypnotic, antipsychotic, antiinflammatory and neuroprotective properties. However, it is well established that CBD produces its biological effects without exerting significant intrinsic activity upon cannabinoid receptors. For this reason, CBD lacks the unwanted psychotropic effects characteristic of marijuana derivatives, so representing one of the bioactive constituents of Cannabis sativa with the highest potential for therapeutic use.The present review reports the pharmacological profile of CBD and summarizes results from preclinical and clinical studies utilizing CBD, alone or in combination with other phytocannabinoids, for the treatment of a number of CNS disorders.

Differential cannabinoid receptor expression during reactive gliosis: a possible implication for a nonpsychotropic neuroprotection.

Activated microglia and astrocytes produce a large number of inflammatory and neurotoxic substances in various brain pathologies, above all during neurodegenerative disorders. In the search for new neuroprotective compounds, interest has turned to marijuana derivatives, since in several in vitro, in vivo, and clinical studies, they have shown a great ability to control neuroinflammation. Despite the emerging evidence regarding pharmacological activities of cannabinoids, their effective introduction into clinical therapy still remains controversial and strongly limited by their unavoidable psychotropicity. Since the psychotropic effect of cannabinoids is generally linked to the activation of the CB1 receptor on neurons, the aim of our review is to clarify the function of the two cannabinoid receptors on glial cells and the differential role played by them, highlighting the emerging evidence of a CB2-mediated control of neuroinflammation that could liberate cannabinoids from the slavery of their central side effects. Despite the emerging evidence regarding pharmacological activities of cannabinoids, however their effective introduction in the clinical therapy remains still controversial and strongly limited by their unavoidable psychotropicity. Since the psychotropic effect of cannabinoids is generally linked to the activation of CB1 receptor on neurons, aim of our review is to clarify the functioning of the two cannabinoid receptors on glial cells and the differential role played by them, highlighting the emerging evidence of a CB2-mediated control of neuro-inflammation that could liberate cannabinoids from the slavery of the central side effects.

Cannabinoid CB1 receptor stimulation affords neuroprotection in MPTP-induced neurotoxicity by attenuating S100B up-regulation in vitro.

In this study, we investigated the mechanism of S100B neurotoxicity and the effect of cannabinoids, in C6 cells treated with 1-methyl-4-phenyl 1,2,3,6 tetrahydropyridine (MPTP) and co-cultured with differentiated PC12 cells. MPTP concentration- and time-dependently increased S100B density in C6 cells. This effect was followed by increased C6 cell proliferation and decreased cell viability of co-cultured PC12 cells. An antibody against S100B, given to PC12 cells before co-culture, led to their survival. Treatment with arachidonyl-2-chloroethylamide, a CB1 agonist, significantly inhibited MPTP-induced S100B density in C6 cells and protected co-cultured PC12 cells from cell death. Because MPTP selectively increased the levels of anandamide in C6 cells, the involvement of the endocannabinoid system was investigated by using selective inhibitors of endocannabinoid inactivation (cellular re-uptake or enzymatic hydrolysis) and selective cannabinoid CB1 and CB2 receptor antagonists and by silencing the CB1 receptor. Our data suggest that selective activation of CB1 receptors by either exogenous or endogenous cannabinoids might afford neuroprotection in MPTP-induced neurotoxicity also by controlling S100B up-regulation in activated glial cells.

Local administration of WIN 55,212-2 reduces chronic granuloma-associated angiogenesis in rat by inhibiting NF-kappaB activation.

Chronic inflammation is often associated with granuloma formation that is a hallmark of many human diseases. The transcription factor nuclear factor-kappa B (NF-kappaB) plays a central role in this process by regulating the expression of several pro-inflammatory genes. Cannabinoids (CBs) from Cannabis sativa L. exert a large number of biological effects including anti-inflammatory and anti-angiogenic effects. In this study, we investigated the role of CBs on granuloma formation induced by lambda-carrageenin-soaked sponge implant in rat. Our results show that local administration of WIN 55,212-2, a CB(1)/CB(2) agonist, given daily or at time of implantation significantly decreased weight and neo-angiogenesis in granuloma tissue and inhibited nuclear factor-kappa B (NF-kappaB)/DNA binding that was associated with a reduced inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2), tumor necrosis factor alpha (TNF-alpha), and vascular endothelial growth factor (VEGF) messenger RNA (mRNA) and protein expression. Also, arachidonyl-2-chloroethylamide (ACEA), a CB(1) selective agonist, and JWH-015, a CB(2) selective agonist, exhibited the same effects that were reversed by SR141716-A and SR144528, respectively, CB(1) and CB(2) selective antagonists. These results indicate that CBs given locally may represent a potential therapeutic tool in controlling chronic inflammation avoiding psychotropic effects.

Oxalomalate affects the inducible nitric oxide synthase expression and activity.

Inducible nitric oxide synthase (iNOS) is an homodimeric enzyme which produces large amounts of nitric oxide (NO) in response to inflammatory stimuli. Several factors affect the synthesis and catalytic activity of iNOS. Particularly, dimerization of NOS monomers is promoted by heme, whereas an intracellular depletion of heme and/or L-arginine considerably decreases NOS resistance to proteolysis. In this study, we found that oxalomalate (OMA, oxalomalic acid, alpha-hydroxy-beta-oxalosuccinic acid), an inhibitor of both aconitase and NADP-dependent isocitrate dehydrogenase, inhibited nitrite production and iNOS protein expression in lipopolysaccharide (LPS)-activated J774 macrophages, without affecting iNOS mRNA content. Furthermore, injection of OMA precursors to LPS-stimulated rats also decreased nitrite production and iNOS expression in isolated peritoneal macrophages. Interestingly, alpha-ketoglutarate or succinyl-CoA administration reversed OMA effect on NO production, thus correlating NO biosynthesis with the anabolic capacity of Krebs cycle. When protein synthesis was blocked by cycloheximide in LPS-activated J774 cells treated with OMA, iNOS protein levels, evaluated by Western blot analysis and (35)S-metabolic labelling, were decreased, suggesting that OMA reduces iNOS biosynthesis and induces an increase in the degradation rate of iNOS protein. Moreover, we showed that OMA inhibits the activity of the iNOS from lung of LPS-treated rats by enzymatic assay. Our results, demonstrating that OMA acts regulating synthesis, catalytic activity and degradation of iNOS, suggest that this compound might have a potential role in reducing the NO overproduction occurring in some pathological conditions.

The marijuana component cannabidiol inhibits beta-amyloid-induced tau protein hyperphosphorylation through Wnt/beta-catenin pathway rescue in PC12 cells.

Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder. A massive accumulation of beta-amyloid (Abeta) peptide aggregates has been proposed as pivotal event in AD. Abeta-induced toxicity is accompanied by a variegated combination of events including oxidative stress. The Wnt pathway has multiple actions in the cascade of events triggered by Abeta, and drugs that rescue Wnt activity may be considered as novel therapeutics for AD treatment. Cannabidiol, a non-psychoactive marijuana component, has been recently proposed as an antioxidant neuroprotective agent in neurodegenerative diseases. Moreover, it has been shown to rescue PC12 cells from toxicity induced by Abeta peptide. However, the molecular mechanism of cannabidiol-induced neuroprotective effect is still unknown. Here, we report that cannabidiol inhibits hyperphosphorylation of tau protein in Abeta-stimulated PC12 neuronal cells, which is one of the most representative hallmarks in AD. The effect of cannabidiol is mediated through the Wnt/beta-catenin pathway rescue in Abeta-stimulated PC12 cells. These results provide new molecular insight regarding the neuroprotective effect of cannabidiol and suggest its possible role in the pharmacological management of AD, especially in view of its low toxicity in humans.

Cannabidiol inhibits inducible nitric oxide synthase protein expression and nitric oxide production in beta-amyloid stimulated PC12 neurons through p38 MAP kinase and NF-kappaB involvement.

In view of the pro-inflammatory scenario observed in Alzheimer's disease, in the recent years anti-inflammatory drugs have been proposed as potential therapeutic agents. We have previously shown that cannabidiol, the main non-psychotropic component from Cannabis sativa, possess a variegate combination of anti-oxidant and anti-apoptotic effects that protect PC12 cells from Abeta toxicity. In parallel, cannabidiol has been described to have anti-inflammatory properties in acute models of inflammation but the possible inhibitory effect of cannabidiol on iNOS protein expression and nitrite production in the nitrosative stress induced by Abeta in neuronal cell-line is un-investigated. Stimulation of differentiated PC12 cells with Abeta (1-42) (1 microg/mL) for 36 h caused a significant increase of nitrite production, compared to un-stimulated cells, that was inhibited in a concentration-dependent manner by both the non-selective iNOS inhibitor, L-NAME (0.3-30 microM), and, at higher extent, by the selective iNOS inhibitor SMT (0.3-30 microM). CBD (10(-6) to 10(-4) M) inhibited both nitrite production and iNOS protein expression induced by Abeta (1-42). Cannabidiol effect was mediated through the inhibition of phosphorylated form of p38 MAP kinase and transcription factor nuclear factor-kappaB activation in a concentration-dependent manner. The here reported data increases our knowledge about the possible neuroprotective mechanism of cannabidiol, highlighting the importance of this compound to inhibit beta-amyloid induced neurodegeneration, in view of its low toxicity in humans.

CB1 receptor selective activation inhibits beta-amyloid-induced iNOS protein expression in C6 cells and subsequently blunts tau protein hyperphosphorylation in co-cultured neurons.

Among the wide range of neuro-inflammatory signalling molecules released by beta-amyloid-stimulated astroglial cells, nitric oxide (NO) plays a fundamental role in AD aethiopathogenesis since it directly promotes neuronal tau protein hyperphosphorylation leading to neurofibrillary tangle formation. Synthetic cannabinoids (CBs), via a selective CB1 receptor activation, negatively modulates both iNOS protein expression and NO production induced by pro-inflammatory stimuli. In this study we investigated the role of both the non-selective WIN 55,212-2 and the selective CB1 receptor agonist, ACEA, on: (i) NO production, (ii) iNOS protein expression in (1-42) beta-amyloid peptide (Abeta)-stimulated C6 rat glioma cells and (iii) tau protein hyperphosphorylation in co-cultured differentiated PC12 neurons. Our results demonstrated that synthetic CBs, by a selective CB1 effect, down-regulate iNOS protein expression and NO production in Abeta-stimulated C6 cells. This effect leads, in turn, to a significant and concentration-dependent inhibition of NO-dependent tau protein hyperphosphorylation in co-cultured PC12 neurons. The results of the present study extend our knowledge about the neuroprotective actions of synthetic CBs on Abeta-dependent neurotoxicity in vitro. Furthermore, our study allows us to identify, in the CB1-mediated inhibition of astroglial-derived NO, a new potential target to blunt tau hyperphosphorylation and the consequent related tauopathy in AD.

The astroglial-derived S100beta protein stimulates the expression of nitric oxide synthase in rodent macrophages through p38 MAP kinase activation.

S100beta is an astroglial-derived Ca2+ -binding protein having neurotrophic role on neurons and glial cells. An aberrant S100beta production has been observed in neurodegenerative disease, as Alzheimer's disease and Down syndrome. S100beta is responsible to start up a gliotic reaction by the release of pro-inflammatory mediators, including nitric oxide (NO) and cytokines from microglia and astrocytes, which are, in turn, deleterious for neurons. Interestingly, pro-inflammatory effect of S100beta seems not be restricted into the brain. Macrophages play a pivotal role in inflammatory diseases, occurring both in the brain and in the periphery. In this study, we tested the hypothesis that S100beta may affect macrophage functions, amplifying thus the inflammatory process. Our results demonstrate that S100beta stimulates both NO production and iNOS protein transcription and expression in J774 and rat peritoneal macrophages. NO production was concentration and time-dependently inhibited by two iNOS inhibitors, L-NAME and SMT. We also demonstrated that S100beta induced oxidative stress by increasing H2O2 production and lipid peroxidation of cell membrane in both macrophage types. The pro-oxidant potential of S100beta activates p38 MAP kinase (MAPK), which has been described to directly activate NF-kappaB. In our study, SB203580, a p38 MAPK inhibitor, and two NF-kappaB inhibitors, TLCK and BAY 11-7082, decreased both NO production and iNOS protein transcription and expression in S100beta-stimulated J774 and peritoneal rat macrophages. Moreover, additional studies demonstrated that S100beta affected also TNF-alpha protein expression in J774 macrophages. In conclusion, our results highlight the potential role of S100beta during an inflammatory scenario identifying macrophages as a novel S100beta-responsive cell-type.

Ultramicronized palmitoylethanolamide reduces viscerovisceral hyperalgesia in a rat model of endometriosis plus ureteral calculosis: role of mast cells.

The effects of ultramicronized palmitoylethanolamide were evaluated on pain behaviours and markers of mast cell (MC) activity in a rat model of endometriosis plus ureteral calculosis (ENDO+STONE)-induced viscerovisceral hyperalgesia (VVH). Female Sprague-Dawley rats that underwent surgical induction of endometriosis were randomly assigned to receive active (ultramicronized palmitoylethanolamide 10 mg·kg(-1)·d(-1), orally) or placebo treatment for 25 days. At day 21, they underwent ureteral stone formation and were video-recorded till day 25 to evaluate ureteral and uterine pain behaviours. At autopsy (day 25), ureteral condition and number and diameter of endometrial cysts were evaluated. The following were then measured: number and percentage of degranulating MCs, number of vessels, chymase, nerve growth factor (NGF), vascular endothelial growth factor (VEGF), and Flk-1 (VEGF receptor) in cysts, and NGF in dorsal root ganglia (DRG). Ultramicronized palmitoylethanolamide-treated vs placebo-treated rats showed significantly lower number, duration and complexity of ureteral crises, shorter duration of uterine pain, and smaller cyst diameter (0.0001 < P < 0.004); a significantly higher percentage of expelled stones (P < 0.0001); significantly lower MC number (P < 0.01), vessel number (P < 0.01), chymase (P < 0.05), NGF (P < 0.05), VEGF (P < 0.01), and Flk-1 (P < 0.01) expression in cysts and NGF expression in DRG (P < 0.01). In all animals, the global duration of ureteral crises correlated linearly and directly with cyst diameter, MC number and chymase in cysts, and NGF in cysts and DRG (0.02 < P < 0.0002). Ultramicronized palmitoylethanolamide significantly reduces VVH from ENDO+STONE, probably by modulating MC expression/activity in cysts, thus reducing central sensitization due to noxious signals from endometriotic lesions. The results suggest potential utility of the compound for VVH in clinics.

Adenosine signalling mediates the anti-inflammatory effects of the COX-2 inhibitor nimesulide.

Extracellular adenosine formation from ATP is controlled by ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase/CD39) and ecto-5'-nucleotidase (e-5NT/CD73); the latter converts AMP to adenosine and inorganic phosphate, representing the rate limiting step controlling the ratio between extracellular ATP and adenosine. Evidence that cellular expression and activity of CD39 and CD73 may be subject to changes under pathophysiological conditions has identified this pathway as an endogenous modulator in several diseases and was shown to be involved in the molecular mechanism of drugs, such as methotrexate, salicylates , interferon-ß. We evaluated whether CD73/adenosine/A2A signalling pathway is involved in nimesulide anti-inflammatory effect, in vivo and in vitro. We found that the adenosine A2A agonist, 4-[2-[[6-amino-9-(N-ethyl-ß-d-ribofuranuronamidosyl)-9H-purin-2-yl]amino]ethyl]benzenepropanoic acid hydrochloride (CGS21680, 2mg/kg ip.), inhibited carrageenan-induced rat paw oedema and the effect was reversed by co-administration of the A2A antagonist -(2-[7-amino-2-[2-furyl][1,2,4]triazolo[2,3-a][1,3,5]triazin-5-yl-amino]ethyl)phenol (ZM241385; 3mg/kg i.p.). Nimesulide (5mg/kg i.p.) anti-inflammatory effect was inhibited by pre-treatment with ZM241385 (3mg/kg i.p.) and by local administration of the CD73 inhibitor, adenosine 5'-(α,ß-methylene)diphosphate (APCP; 400µg/paw). Furthermore, we found increased activity of 5'-nucleotidase/CD73 in paws and plasma of nimesulide treated rats, 4h following oedema induction. In vitro, the inhibitory effect of nimesulide on nitrite and prostaglandin E2 production by lipopolysaccharide-activated J774 cell line was reversed by ZM241385 and APCP. Furthermore, nimesulide increased CD73 activity in J774 macrophages while it did not inhibit nitrite accumulation by lipopolysaccharide-activated SiRNA CD73 silenced J774 macrophages. Our data demonstrate that the anti-inflammatory effect of nimesulide in part is mediated by CD73-derived adenosine acting on A2A receptors.

Novel non-peptide small molecules preventing IKKß/NEMO association inhibit NF-κB activation in LPS-stimulated J774 macrophages.

Nuclear Factor-κB (NF-κB) is a transcription factor regulating several genes involved in important physiological and pathological processes. NF-κB has been found constitutively activated in many inflammatory/immune diseases. In addition, a positive correlation between persistent activation of NF-κB and tumor promotion has been demonstrated. Since the IKK (IκB kinase) activation is an indispensable component of all pro-inflammatory signaling pathways leading to NF-κB activation, considerable efforts have been done in order to develop novel anti-inflammatory therapeutics targeting IKK. Association of the IKK complex relies on critical interactions between the C-terminus NBD (NEMO binding domain) of the catalytic subunits IKKα and IKKß, and the regulatory subunit NEMO (NF-κB Essential Modulator). Thus, this IKK/NEMO interacting region provides an attractive target to prevent the IKK complex formation and NF-κB activation. In this regard, we have identified non-peptide small molecule disruptors of IKKß/NEMO complex through a structure-based virtual screening (SBVS) of the NCI chemical library. Phenothiazine 22 and its close analogues (22.2, 22.4 and 22.10) were able to reduce nitrite production and iNOS mRNA expression in J774 murine macrophages stimulated with LPS for 24h. These effects were associated with a reduced NF-κB/DNA binding activity as well as a decreased expression of phosphorylated IKKß, IκBα and NF-κB/p65 in these cells. These observations suggest that compound 22 and its three structural analogues by inhibiting IKKß/NEMO association mediate the blockage of NF-κB signaling pathway and may prove effective in treatment of diseases in which the IKK/NF-κB pathway is dysregulated.