Cannabinoid Receptor Binding Research Articles

COMPARISON OF BIOPHARMACEUTICAL PARAMETERS OF CANNABINOIDS AND NON-STEROIDAL ANTI-INFLAMMATORY DRUGS BY QSAR METHOD

Objective: To prove the benefits of biopharmaceutical parameters of cannabinoids over NSAIDs using quantitative structure and activity relationships (QSAR). Methods: The topological indices of Wiener (W) and Balaban (J) were calculated using the previously developed original program ChemicDescript (certificate no. 2003612305). Results: It was shown that the calculated topological indices were in one-to-one correspondence with such biopharmaceutical parameters as the constants of equilibrium binding to cannabinoid receptors CB1 and CB2, toxicity, and lipophilicity. For example, it was shown that when the Wiener index changes from 480 to 530 LogK increases from 1.0 to 3.5. The LD50-W/J and logP-W/J diagrams demonstrate that cannabinoids are less toxic and more lipophilic than NSAIDs. Cannabidiol and cannabinol, having close values of their topological indices and insignificant psychoactivity, have the highest LD50 values, i.e. they are the least toxic. Moreover, for synthetic cannabinoids–nabilone and THJ-2201–the Wiener index is approximately 2 times higher than for plant analogues. Conclusion: In connection with the successful promotion of cannabinoid analgesics in the global pharmaceutical market, the results obtained are important for demonstrating their advantages over NSAIDs in terms of toxicity and lipophilicity. The results demonstrate the possibility of predicting the cannabinoid receptor binding energy of synthetic and newly identified plant cannabinoids, as well as assessing their toxicity and lipophilicity.

Induction of Liver Size Reduction in Zebrafish Larvae by the Emerging Synthetic Cannabinoid 4F-MDMB-BINACA and Its Impact on Drug Metabolism.

Zebrafish (ZF; Danio rerio) larvae have become a popular in vivo model in drug metabolism studies. Here, we investigated the metabolism of methyl 2-[1-(4-fluorobutyl)-1H-indazole-3-carboxamido]-3,3-dimethylbutanoate (4F-MDMB-BINACA) in ZF larvae after direct administration of the cannabinoid via microinjection, and we visualized the spatial distributions of the parent compound and its metabolites by mass spectrometry imaging (MSI). Furthermore, using genetically modified ZF larvae, the role of cannabinoid receptor type 1 (CB1) and type 2 (CB2) on drug metabolism was studied. Receptor-deficient ZF mutant larvae were created using morpholino oligonucleotides (MOs), and CB2-deficiency had a critical impact on liver development of ZF larva, leading to a significant reduction of liver size. A similar phenotype was observed when treating wild-type ZF larvae with 4F-MDMB-BINACA. Thus, we reasoned that the cannabinoid-induced impaired liver development might also influence its metabolic function. Studying the metabolism of two synthetic cannabinoids, 4F-MDMB-BINACA and methyl 2-(1-(5-fluoropentyl)-1H-pyrrolo[2,3-b]pyridine-3-carboxamido)-3,3-dimethylbutanoate (7′N-5F-ADB), revealed important insights into the in vivo metabolism of these compounds and the role of cannabinoid receptor binding.

Persistent Inflammation Reduces Cannabinoid 1 Receptor Function in the Ventrolateral Periaqueductal Gray

Cannabinoid receptors (CBRs) are sensitive to environmental perturbations and we have previously observed that presynaptic cannabinoid 1 receptor (CB1R) inhibition of GABA release is reduced but that presynaptic cannabinoid 2 receptor (CB2R) function is increased by persistent inflammation in the rostral ventromedial medulla (RVM). The goal of this study is to determine the effect of persistent inflammation on CBRs within the ventrolateral periaqueductal gray (vlPAG), a region upstream of the RVM in the descending pain modulatory pathway. CB1R-mediated inhibition of GABA release was assessed with whole cell patch clamp electrophysiology measuring spontaneous miniature inhibitory postsynaptic currents (mIPSC) and electrically evoked inhibitory postsynaptic currents (eIPSCs). CBR binding was measured from microdissected vlPAG tissue with radioligand binding saturation curves using [3H]CP-55,940. In brain slices from naïve rats, the CBR agonist WIN55,212-2 (3 µM) suppressed presynaptic GABA release and this effect was reversed by application of the CB1R-specific antagonist rimonabant (3 µM). After persistent inflammation (5-7 days) induced by subcutaneous injection of Complete Freund's Adjuvent (CFA) into the hindpaw, WIN55,212 no longer suppressed spontaneous or evoked GABA release. Further, this effect was selective to CBRs as persistent inflammation did not impact presynaptic mu-opioid receptor inhibition of GABA release. To determine if CFA-induced neural activity elevates endocannabinoids that desensitize CB1Rs, we tested CB1R function 24h after CFA injection. WIN55,212 inhibition of GABA release was normal, similar to vlPAG slices from naïve rats at this timepoint, indicating that the mechanism underlying the loss of CB1R function takes longer than 24h and is likely not due to the increased spontaneous neural activity immediately following CFA injection. Radioligand saturation curves in vlPAG tissue indicated no effect of 5-7d CFA treatment on CBR density or kinetics. Since CP-55,940 is a nonselective CBR agonist, the binding results could be due to increased CB2R expression. However, electrophysiological experiments indicated no increase in CB2R receptor function in the vlPAG after persistent inflammation. These results are in stark contrast to the CBR regulation observed previously in the RVM. Together these data indicate that persistent inflammation reduced CB1R function in the vlPAG through a mechanism that requires more than 24h. The discrepancy in CB2R activity between the vlPAG and RVM after CFA indicates that CBRs in these brain regions are differentially impacted by persistent inflammation- but in both regions CB1R function is significantly reduced. Future experiments are focused on the underlying mechanisms resulting in decreased CB1R function in presynaptic terminals following persistent inflammation.

Shared Binding Mode of Perrottetinene and Tetrahydrocannabinol Diastereomers inside the CB1 Receptor May Incentivize Novel Medicinal Drug Design: Findings from an in Silico Assay.

In recent years, therapeutic compounds derived from phytocannabinoids have brought renewed attention to the benefits they offer to ameliorate chronic disease symptoms. Among cannabinoids, tetrahydrocannabinol (THC) is a well-known component of the Cannabis plant, whose active principles have been studied through the years. Another psychoactive phytocannabinoid, derived from liverworts Radula, perrottetinene (PET), has created interest, especially as a pharmaceutical product and for its legal recreational use. Unfortunately, so far, the interaction mode of these compounds at the type 1 cannabinoid receptors (CB1R) binding site remains unknown, and no experimental three-dimensional structure in complex with THC or PET is available in the Protein Data Bank. Today, many computational methodologies can assist in this crusade and help unveil how these molecules bind, based on the already known pose of a structurally similar compound. In this work, we aim to elucidate the binding mode of THC and PET molecules in both cis and trans conformers, using a combination of several computational methodologies, including molecular docking, molecular dynamics, free energy calculations, and protein-energy network studies. We found that THC and PET interact similarly with the CB1R, in a different conformation depending on the considered diastereomer. We have observed that cis ligands adopted a half-chair conformation of the cycle ring containing the dimethyl group, assuming an axial or equatorial conformation producing a different induced fitting of the surrounding residues compared with trans ligands, with higher interaction energy than the trans conformer. For PET, we have seen that Trp-279 and Trp-356 have a marked influence on the binding. After binding, Trp-279 accommodates its side chain to better interact with the PET's terminal phenyl group, disturbing CB1R residues communication. The interaction with Trp-356 might impair the activation of CB1R and can influence the binding of PET as a partial agonist. Understanding the PET association with CB1R from a molecular perspective can offer a glimpse of preventing potential toxicological or recreational effects since it is an attractive lead for drug development with fewer side effects than trans-THC.

Δ9 -Tetrahydrocannabinolic acid alleviates collagen-induced arthritis: Role of PPARγ and CB1 receptors.

Δ9 -Tetrahydrocannabinolic acid (Δ9 -THCA-A), the precursor of Δ9 -THC, is a non-psychotropic phytocannabinoid that shows PPARγ agonist activity. Here, we investigated the ability of Δ9 -THCA-A to modulate the classic cannabinoid CB1 and CB2 receptors and evaluated its anti-arthritis activity in vitro and in vivo. Cannabinoid receptors binding and intrinsic activity, as well as their downstream signalling, were analysed in vitro and in silico. The anti-arthritis properties of Δ9 -THCA-A were studied in human chondrocytes and in the murine model of collagen-induced arthritis (CIA). Plasma disease biomarkers were identified by LC-MS/MS based on proteomic and elisa assays. Functional and docking analyses showed that Δ9 -THCA-A can act as an orthosteric CB1 receptor agonist and also as a positive allosteric modulator in the presence of CP-55,940. Also, Δ9 -THCA-A seemed to be an inverse agonist for CB2 receptors. In vivo, Δ9 -THCA-A reduced arthritis in CIA mice, preventing the infiltration of inflammatory cells, synovium hyperplasia, and cartilage damage. Furthermore, Δ9 -THCA-A inhibited expression of inflammatory and catabolic genes on knee joints. The anti-arthritic effect of Δ9 -THCA-A was blocked by either SR141716 or T0070907. Analysis of plasma biomarkers, and determination of cytokines and anti-collagen antibodies confirmed that Δ9 -THCA-A mediated its activity mainly through PPARγ and CB1 receptor pathways. Δ9 -THCA-A modulates CB1 receptors through the orthosteric and allosteric binding sites. In addition, Δ9 -THCA-A exerts anti-arthritis activity through CB1 receptors and PPARγ pathways, highlighting its potential for the treatment of chronic inflammatory diseases such as rheumatoid arthritis.

Mechanisms for the Risk of Acute Coronary Syndrome and Arrhythmia Associated With Phytogenic and Synthetic Cannabinoid Use.

Phytogenic cannabinoids from Cannabis sativa and synthetic cannabinoids are commonly used substances for their recreational and medicinal properties. There are increasing reports of cardiotoxicity in close temporal association with cannabinoid use in patients with structurally normal hearts and absence of coronary arterial disease. Associated adverse events include myocardial ischemia, conduction abnormalities, arrhythmias, and sudden death. This review details the effects of phytogenic and synthetic cannabinoids on diverse receptors based on evidence from in vitro, human, and animal studies to establish a molecular basis for these deleterious clinical effects. The synergism between endocannabinoid dysregulation, cannabinoid receptor, and noncannabinoid receptor binding, and impact on cellular ion flux and coronary microvascular circulation is delineated. Pharmacogenetic factors placing certain patients at higher risk for cardiotoxicity are also correlated with the diverse effects of cannabinoids.

Long-term systemic administration of kynurenic acid brain region specifically elevates the abundance of functional CB1 receptors in rats

Kynurenic acid (KYNA) is one of the most significant metabolite of the kynurenine pathway both in terms of functional and potential therapeutic value. It is an N-methyl-D-aspartate (NMDA) receptor antagonist, but it can also activate the G-protein coupled receptor 35 (GPR35), which shares several structural and functional properties with cannabinoid receptors. Previously our group demonstrated that systemic chronic KYNA treatment altered opioid receptor G-protein activity. Opioid receptors also overlap in many features with cannabinoid receptors. Thus, our aim was to examine the direct in vitro and systemic, chronic in vivo effect of KYNA on type 1 cannabinoid receptor (CB1R) binding and G-protein activity.Based on competition and [35S]GTPγS G-protein binding assays in rat brain, KYNA alone did not show significant binding towards the CB1R, nor did it alter CB1R ligand binding and agonist activity in vitro. When rats were chronically treated with KYNA (single daily, i.p., 128 mg/kg for 9 days), the KYNA plasma and cerebrospinal fluid levels significantly increased compared to vehicle treated group. Furthermore, in G-protein binding assays, in the whole brain the amount of G-proteins in basal and in maximum activity coupled to the CB1R also increased due to the treatment. At the same time, the overall stimulatory properties of the receptor remained unaltered in vehicle and KYNA treated samples. Similar observations were made in rat hippocampus, but not in the cortex and brainstem. In saturation binding assays the density of CB1Rs in rat whole brain and hippocampus were also significantly enhanced after the same treatment, without significantly affecting ligand binding affinity.Thus, KYNA indirectly and brain region specifically increases the abundance of functional CB1Rs, without modifying the overall binding and activity of the receptor. Supposedly, this can be a compensatory mechanism on the part of the endocannabinoid system induced by the long-term KYNA exposure.

Metabolism, CB1 cannabinoid receptor binding and in vivo activity of synthetic cannabinoid 5F-AKB48: Implications for toxicity

AKB48 and its fluorinated derivative 5F-AKB48 are synthetic cannabinoids (SCs) which have caused hospitalizations and deaths in human users. Abuse of SCs is dangerous because users may mistake them for natural cannabis, which is generally considered to be unlikely to elicit adverse effects. The present studies were designed to investigate the in vitro oxidative metabolism of 5F-AKB48 by human microsomal fractions from different organs and sexes as well as recombinant human cytochrome P450s (P450s). Mass spectrometry data tentatively provides evidence for the existence of mono-, di-, and trihydroxylated metabolites in a successive metabolism. Experiments utilizing P450s revealed that the most active enzymes (CYP2D6, CYP2J2, CYP3A4, and CYP3A5) effectively produced mono- and dihydroxylated metabolites, while CYP3A4/5 also produced significant amounts of the trihydroxylated metabolite. Moreover, although the affinity and potency of Phase I metabolite 4OH-5F-AKB48 is reduced when compared to that of the parent drug, this metabolite nevertheless retains similar high affinity for CB1 receptors, and greater efficacy for G protein activation, when compared to THC. Finally, 5F-AKB48 produced time- and dose-dependent cannabimimetic effects in mice which were more potent, but shorter acting, than those of Δ9-THC, and were attenuated by prior treatment with the CB1 antagonist rimonabant. Based on our data, we hypothesize that while many cases of toxicity result from genetic mutations, which can lead to a decrease or even absence of activity for Phase I drug-metabolizing enzymes, other P450s could potentially increase their role in the metabolism of these SCs. Because many metabolites of SCs remain biologically active, they could contribute to the deleterious effects of these substances.

Synthetic bioactive olivetol-related amides: The influence of the phenolic group in cannabinoid receptor activity

Focusing on the importance of the free phenolic hydroxyl moiety, a family of 23 alkylresorcinol-based compounds were developed and evaluated for their cannabinoid receptor binding properties. The non-symmetrical hexylresorcinol derivative 29 turned out to be a CB2-selective competitive antagonist/inverse agonist endowed with good potency. Both the olivetol- and 5-(2-methyloctan-2-yl)resorcinol-based derivatives 23 and 24 exhibited a significant antinociceptive activity. Interestingly, compound 24 proved to be able to activate both cannabinoid and TRPV1 receptors. Even if cannabinoid receptor subtype selectivity remained a goal only partially achieved, results confirm the validity of the alkylresorcinol nucleus as skeleton for the identification of potent cannabinoid receptor modulators.

Cannabidiol improves behavioural and neurochemical deficits in adult female offspring of the maternal immune activation (poly I:C) model of neurodevelopmental disorders

Cognitive impairment is a major source of disability in schizophrenia and current antipsychotic drugs (APDs) have minimal efficacy for this symptom domain. Cannabidiol (CBD), the major non-intoxicating component of Cannabis sativa L., exhibits antipsychotic and neuroprotective properties. We recently reported the effects of CBD on cognition in male offspring of a maternal immune activation (polyinosinic-polycytidilic acid (poly I:C)) model relevant to the aetiology of schizophrenia; however, the effects of CBD treatment in females are unknown. Sex differences are observed in the onset of schizophrenia symptoms and response to APD treatment. Furthermore, the endogenous cannabinoid system, a direct target of CBD, is sexually dimorphic in humans and rodents. Therefore, the present work aimed to assess the therapeutic impact of CBD treatment on behaviour and neurochemical signalling markers in female poly I:C offspring. Time-mated pregnant Sprague-Dawley rats (n = 16) were administered poly I:C (4 mg/kg; i.v.) or saline (control) on gestational day 15. From postnatal day 56, female offspring received CBD (10 mg/kg, i.p.) or vehicle treatment for approximately 3 weeks. Following 2 weeks of CBD treatment, offspring underwent behavioural testing, including the novel object recognition, rewarded alternation T-maze and social interaction tests to assess recognition memory, working memory and sociability, respectively. After 3 weeks of CBD treatment, the prefrontal cortex (PFC) and hippocampus (HPC) were collected to assess effects on endocannabinoid, glutamatergic and gamma-aminobutyric acid (GABA) signalling markers. CBD attenuated poly I:C-induced deficits in recognition memory, social interaction and glutamatergic N-methyl-d-aspartate receptor (NMDAR) binding in the PFC of poly I:C offspring. Working memory performance was similar between treatment groups. CBD also increased glutamate decarboxylase 67, the rate-limiting enzyme that converts glutamate to GABA, and parvalbumin protein levels in the HPC. In contrast to the CBD treatment effects observed in poly I:C offspring, CBD administration to control rats reduced social interaction, cannabinoid CB1 receptor and NMDAR binding density in the PFC, suggesting that CBD administration to healthy rats may have negative consequences on social behaviour and brain maturation in adulthood. Overall, the findings of this study support the therapeutic benefits of CBD on recognition memory and sociability in female poly I:C offspring, and provide insight into the neurochemical changes that may underlie the therapeutic benefits of CBD in the poly I:C model.

Effect of cannabidiol on endocannabinoid, glutamatergic and GABAergic signalling markers in male offspring of a maternal immune activation (poly I:C) model relevant to schizophrenia

The mainstay treatment for schizophrenia is antipsychotic drugs (APDs), which are mostly effective against the positive symptoms (e.g. hallucinations), but provide minimal benefits for the negative symptoms (e.g. social withdrawal) and cognitive deficits. We have recently shown that treatment with the non-intoxicating phytocannabinoid, cannabidiol (CBD), can improve cognition and social interaction deficits in a maternal immune activation (MIA) model relevant to the aetiology of schizophrenia, however, the mechanisms underlying this effect are unknown. An imbalance in the main excitatory (glutamate) and inhibitory (GABA) neurotransmitter systems in the brain plays a role in the pathophysiology of schizophrenia. Therefore, the endocannabinoid system could represent a therapeutic target for schizophrenia as a regulator of glutamate and GABA release via the CB1 receptor (CB1R). This study investigated the effects of chronic CBD treatment on markers of glutamatergic, GABAergic and endocannabinoid signalling in brain regions implicated in social behaviour and cognitive function, including the prefrontal cortex (PFC) and hippocampus (HPC). Time-mated pregnant Sprague-Dawley rats (n = 16) were administered poly I:C (4 mg/kg, i.v.) or saline (control) on gestational day 15. Male offspring were injected with CBD (10 mg/kg, i.p.) or vehicle twice daily from postnatal day 56 for 3 weeks. The prefrontal cortex (PFC) and hippocampus (HPC) were collected for post-mortem receptor binding and Western blot analyses (n = 8 per group). CBD treatment attenuated poly I:C-induced deficits in cannabinoid CB1 receptor binding in the PFC and glutamate decarboxylase 67, the enzyme that converts glutamate to GABA, in the HPC. CBD treatment increased parvalbumin levels in the HPC, regardless of whether offspring were exposed to poly I:C in utero. Conversely, CBD did not affect N-methyl-d-aspartate receptor and gamma-aminobutyric acid (GABA) A receptor binding or protein levels of fatty acid amide hydrolase, the enzyme that degrades the endocannabinoid, anandamide. Overall, these findings show that CBD can restore cannabinoid/GABAergic signalling deficits in regions of the brain implicated in schizophrenia pathophysiology following maternal poly I:C exposure. These findings provide novel evidence for the potential mechanisms underlying the therapeutic effects of CBD treatment in the poly I:C model.

COMPARATIVE BIOLOGICAL EVALUATION OF FOUR ENDOPHYTIC FUNGI ISOLATED FROM NIGELLA SATIVA SEEDS

In this study, a total of four endophytic fungi have been isolated from Nigella sativa (Ranunculaceae) seeds growing in Egypt. The isolated fungi were identified morphologically and microscopically up to species to be; Alternaria pluriseptata, Aspergillus tubingensis, Aspergillus parasiticus and Eurotium pseudoglaucus. The extracts of the all identified fungi were screened biologically for antileukemic, cytotoxic, antimalarial, antileishmanial, antimicrobial, antioxidant and anti-inflammatory activities as well as for cannabinoid and opioid receptor binding affinities. All the examined fungal extracts showed good antileukemic activities with Ic50 values ranging from 0.025 to 0.8 µg/ml, while two of them showed cytotoxic activities against Pig kidney epithelial (LLC-PK1) cells. Two fungal extracts exhibited antimalarial activities, three showed antioxidant activities and two exhibited anti-inflammatory activities

COMPARATIVE BIOLOGICAL EVALUATION OF SIX ENDOPHYTIC FUNGI ISOLATED FROM VINCA ROSEA LEAVES

In this study, a total of six endophytic fungi have been isolated from Vinca rosea (Apocynaceae) leaves growing in Egypt. The isolated fungi were identified morphologically and microscopically up to species to be; Alternaria phragmospora, Aspergillus awamori, Penicillium duclauxii, Penicillium melinii, Nigrospora sphaerica and Mucor ramosissimus. The extracts of the all identified fungi were screened biologically for antileukemic, cytotoxic, antimalarial, antileishmanial, antimicrobial, antioxidant and anti-inflammatory activities as well as for cannabinoid and opioid receptor binding affinities. Out of the six examined fungal extracts four exhibited promising antimalarial activities, four showed modeate antileukemic activities and two of them exhibited cytotoxic activities, three showed antioxidant activities, three exhibited anti-inflammatory activities, and the only one showed an antifungal activity. Alternaria phragmospora was the most active antimalarial agent inhibiting Plasmodium falciparum D6 and W2 clones with IC50 values of 1.9 and 2.1 μg/mL, respectively. Alternaria phragmospora extractwas subjected to liquid-liquid partition using 90% MeOH, hexane then BuOH and H2O. MeOH and BuOH fractions exhibited strong activities against Plasmodium falciparum D6 clone with IC50 values of 1.3 and 28 μg/mL and W2 clone with IC50 values of 1.4 and 28 μg/mL, respectively. These results may be an excellent opportunity to get a new antimalarial drug derived from endophytic fungi.

New flavans and stilbenes from Cyperus conglomeratus

The chromatographic investigation of Cyperus conglomeratus Rottb. aerial parts resulted in the isolation of three new flavan derivatives, 7,3′-dihydroxy-8,4′-dimethoxyflavan (1), 7,4′-dihydroxy-5,3′-dimethoxy-8-methylflavan (2) and 7,4′-dihydroxy-5,3′-dimethoxy-8-prenylflavan (3), and two new stilbene derivatives, 4-hydroxy-5′-methoxy-6′′,6′′-dimethylpyran[2′′,3′′: 3′, 2′]stilbene (4) and 4′-hydroxy-3,5-dimethoxy-2-prenylstilbene (5), along with four known compounds, 5,4′-dihydroxy-7,3′-dimethoxyflavan (6), 3′,4′-dimethoxyluteolin (7), 3′,4-dihydroxy-5′-methoxy-2′-prenylstilbene (8), and 4,4′-dihydroxy-3,3′-dimethoxy-2′-prenylstilbene (9). The structures were established by their 1D, 2D NMR and MS spectral data. The new compounds 1-5 were tested for cannabinoid and opioid receptor binding. Compounds 1, 3, 4, and 5 exhibited moderate activity (>50% displacement) towards μ-opioid receptor.

Positron emission tomography imaging of cerebral glucose metabolism and type 1 cannabinoid receptor availability during temporal lobe epileptogenesis in the amygdala kindling model in rhesus monkeys.

We investigated changes in the endocannabinoid system and glucose metabolism during temporal lobe epileptogenesis. Because it is rarely possible to study epileptogenesis in humans, we applied the electrical amygdala kindling model in nonhuman primates to image longitudinal changes in type 1 cannabinoid receptor (CB1R) binding and cerebral glucose metabolism. Two rhesus monkeys received [18 F]-MK-9470 and fluorodeoxyglucose-positron emission tomography ([18 F]-FDG -PET) scans in each of the 4 kindling stages to quantify relative changes over time of CB1R binding and cerebral glucose metabolism in vivo. We constructed z-score images relative to a control group (n = 8), and considered only those changes measured in both kindled animals by calculating the binary conjunction image per kindling stage. The seizure-onset zone exhibited an increased CB1R binding and a decreased glucose metabolism, which both aggravated gradually in extent and intensity throughout kindling. The ipsilateral thalamus and insula showed hypometabolism that coincided with an increase and a decrease in CB1R binding, respectively. These changes also became gradually more severe throughout kindling and overlapped with ictal perfusion changes during the final stage of amygdala kindling, with hyperperfusion in the ipsilateral thalamus and hypoperfusion in the ipsilateral insula. The observed changes in CB1R binding may reflect a combination of a protective mechanism of neurons against seizure activity that becomes stronger over time to combat more severe seizures, and on the other hand, a process of epileptogenesis that facilitates seizure activity and generalization, depending on the cell type involved in those specific regions. This study provides unique evidence that the CB1R is dynamically and progressively involved from the start of mesial temporal lobe epileptogenesis.

Chemical and biological studies on Cichorium intybus L.

Cichorium intybus L. (Asteraceae family) is a world-wide grown plant known as chicory. In traditional medicine, this plant is used as diuretic, anti-inflammatory, digestive, cardiotonic and liver tonic. Chromatographic purification of the supercritical fluid extract of aerial parts of C. intybus on silica gel column led to isolation of three compounds: new compound, 28β-hydroxytaraxasterol (I), and two known compounds usnic acid (II) and β-sitosterol (III). Purification of the ethanolic extract of aerial parts of this plant on silica gel column chromatography yielded four compounds: 1,3-dioleylglycerate (IV), sitoindoside II (V), 11β-13-dihydrolactucin (VI) and β-sitosterol-3-O-glucoside (VII). The structures of the isolated compounds were determined by their 1D, 2D NMR and MS spectral data. All the fractions and isolated compounds were tested for cannabinoid and opioid receptor binding, as well as antibacterial, antifungal and antimalarial activities. Compound I showed moderate activity (60.5% displacement) towards CB1 receptor.

New tetranorlabdanoic acid from aerial parts of Salvia aethiopis

Salvia aethiopis is a perennial plant native to Eurasia and known by the common names Mediterranean sage or African sage. This plant has been used in Iranian medicine as a carminative and tonic. The ethanolic extract of aerial part of S. aethiopis exhibited moderate to weak activity towards delta and kappa opioid receptors (46.3 and 45.3% displacement, respectively). Chromatographic purification of the ethanolic extract on silica gel column led to isolation of one new: 3α-hydroxy-8α-acetoxy-13,14,15,16-tetranorlabdan-12-oic acid (I) and three known compounds: sesquiterpene spathulenol (II), β-sitosterol (III) and β-sitosterol-3-O-glucoside (IV). The structures of all isolated compounds were elucidated by their NMR (1D and 2D) and MS spectral data. All the fractions and isolated compounds were tested for cannabinoid and opioid receptor binding assays.

Phytochemical and biological evaluation of Salvia apiana

Salvia apiana (white sage, Lamiaceae family) plant is native to southern California and parts of Mexico. Some Native American tribes local to this region consider S. apiana to be sacred and burn the leaves as incense for purification ceremonies. The plant has been used to treat sore throats, coughs, chest colds, upper respiratory infections and poison oak rashes. The aqueous ethanolic extract of S. apiana showed moderate CB1 activity (58.3% displacement). Chromatographic purification of the ethanolic extract on silica gel column led to isolation of nine compounds: rosmadial (I), carnosol (II), 16-hydroxycarnosol (III), sageone (IV), cirsimaritin (V), salvigenin (VI), oleanolic acid (VII), 3β,28-dihydroxy-urs-12-ene (VIII), and ursolic acid (IX). The structures of the isolated compounds were determined by their 1D, 2D NMR and MS spectral data. All the fractions and isolated compounds were tested for cannabinoid and opioid receptor binding.

Decreased CB receptor binding and cannabinoid signaling in three brain regions of a rat model of schizophrenia

Schizophrenia is a serious mental health disorder characterized by several behavioral and biochemicel abnormalities. In a previous study we have shown that mu-opioid (MOP) receptor signaling is impaired in specific brain regions of our three-hit animal model of schizophrenia. Since the cannabinoid system is significantly influenced in schizophrenic patients, in the present work we investigated cannabinoid (CB) receptor binding and G-protein activation in cortical, subcortical and cerebellar regions of control and ‘schizophrenic’ rats. Cannabinoid agonist (WIN-55,212-2 mesylate) mediated G-protein activation was consistently decreased in all areas tested, and the difference was extremely significant in membranes prepared from the cerebellum. Interestingly, the cerebellar activity of WIN-55,212-2 stimulated G-proteins was substantially higher than those of cerebral cortex and subcortical region in control animals, indicating a primordial role of the cannabinoid system in the cerebellum. At the level of radioligand binding, the affinities of the CB receptors were also markedly decreased in the model animals. Capacity of the [3H]WIN-55,212-2 binding was only higher in the cerebellum of ‘schizophrenic’ model rats. Taken together, in all three brain areas of model rats both cannabinoid receptor binding and cannabinoid agonist-mediated G-protein activation were regularly decreased. Our results revealed that besides the opioids, the endocannabinoid – cannabis receptor system also shows impairment in our rat model, increasing its face validity and translational utility.

Acute Poisonings from Synthetic Cannabinoids — 50 U.S. Toxicology Investigators Consortium Registry Sites, 2010–2015

Recent reports suggest that acute intoxications by synthetic cannabinoids are increasing in the United States (1,2). Synthetic cannabinoids, which were research compounds in the 1980s, are now produced overseas; the first shipment recognized to contain synthetic cannabinoids was seized at a U.S. border in 2008 (3). Fifteen synthetic cannabinoids are Schedule I controlled substances (3), but enforcement is hampered by the continual introduction of new chemical compounds (1,3). Studies of synthetic cannabinoids indicate higher cannabinoid receptor binding affinities, effects two to 100 times more potent than Δ(9)-tetrahydrocannabinol (the principal psychoactive constituent of cannabis), noncannabinoid receptor binding, and genotoxicity (4,5). Acute synthetic cannabinoid exposure reportedly causes a range of mild to severe neuropsychiatric, cardiovascular, renal, and other effects (4,6,7); chronic use might lead to psychosis (6,8). During 2010-2015, physicians in the Toxicology Investigators Consortium (ToxIC) treated 456 patients for synthetic cannabinoid intoxications; 277 of the 456 patients reported synthetic cannabinoids as the sole toxicologic agent. Among these 277 patients, the most common clinical signs of intoxication were neurologic (agitation, central nervous system depression/coma, and delirium/toxic psychosis). Relative to all cases logged by 50 different sites in the ToxIC Case Registry, there was a statistically significant association between reporting year and the annual proportion of synthetic cannabinoid cases. In 2015, reported cases of synthetic cannabinoid intoxication increased at several ToxIC sites, corroborating reported upward trends in the numbers of such cases (1,2) and underscoring the need for prevention.