Tumor necrosis factor α, and agonist and antagonists of cannabinoid receptor type 1 and type 2 alter the immunophenotype of stem cells from human exfoliated deciduous teeth

ABSTRACT Objective To verify the involvement of the endocannabinoid system in the immunomodulatory profile of stem cells from human exfoliated deciduous teeth, in the presence or absence of TNF-α, and agonist and antagonists of CB1 and CB2. Methods Stem cells from human exfoliated deciduous teeth were cultured in the presence or absence of an agonist, anandamide, and two antagonists, AM251 and SR144528, of CB1 and CB2 receptors, with or without TNF-α stimulation. For analysis of immunomodulation, surface molecules linked to immunomodulation, namely human leukocyte antigen-DR isotype (HLA-DR), and programmed death ligands 1 (PD-L1) and 2 (PD-L2) were measured using flow cytometry. Results The inhibition of endocannabinoid receptors together with the proinflammatory effect of TNF-α resulted in increased HLA-DR expression in stem cells from human exfoliated deciduous teeth, as well as, in these cells acquiring an anti-inflammatory profile by enhancing the expression of PD-L1 and PD-L2. Conclusion Stem cells from human exfoliated deciduous teeth respond to the endocannabinoid system and TNF-α by altering key immune response molecules.

Endocannabinoid system and periodontitis: mechanisms and therapeutic implications / Sistema endocanabinoide e periodontite: mecanismos e implicações terapêuticas

Introdução: A periodontite é um importante problema de saúde pública. Embora o princípio da terapia da periodontite esteja focado principalmente na remoção do biofilme dental e dos fatores associados, sua fisiopatologia registra diferentes eventos moleculares e inflamatórios relacionados ao sistema imunológico do hospedeiro, como a participação do sistema endocanabinoide. Objetivo: Esta revisão teve como objetivo explorar e elucidar os mecanismos e papéis do sistema endocanabinoide na fisiopatologia da periodontite e suas possibilidades para futuras terapias relacionadas. Material e método: Realizou-se uma busca eletrônica na plataforma PubMed por estudos envolvendo a ação do sistema endocanabinoide sobre a periodontite. Resultado: Dezenove estudos clínicos e pré-clínicos foram incluídos nesta revisão narrativa. Conclusão: Os receptores canabinoides tipo 1 e 2 são componentes integrais do sistema endocanabinoide e manifestam-se de várias formas nos tecidos periodontais. As ações e mecanismos através dos quais os receptores canabinoides são ativados em locais saudáveis ou inflamados continuam a ser o foco de investigações em curso. Além disso, os fitocanabinoides e canabinoides sintéticos apresentam potencial como tratamentos, com estudos pré-clínicos indicando benefícios na redução da inflamação e na facilitação da reparação dos tecidos.

Introduction: Periodontitis is a major public health problem. Although the principle of periodontitis therapy is mainly focused on removing dental biofilm and associated factors, its physiopathology enrolls different molecular and inflammatory events related to the host immune system, as the participation of the endocannabinoid system. Objective: This review aimed to explore and elucidate the mechanisms and roles of the endocannabinoid system on periodontitis physiopathology and its possibilities for future related therapies. Material and method: An electronic search was carried out on the PubMed platform for studies involving the action of the endocannabinoid system on periodontitis. Result: Nineteen clinical and preclinical studies were included in this narrative review. Conclusion: Cannabinoid receptors type 1 and 2 are integral components of the endocannabinoid system, manifesting in various forms in the periodontal tissues. The actions and mechanisms through which cannabinoid receptors are activated in healthy or inflamed sites remain the focus of ongoing investigations. Moreover, phytocannabinoids and synthetic cannabinoids show therapeutic potential, with pre-clinical studies indicating benefits in reducing inflammation and facilitating tissue repair

Propofol relieves the subcutaneous chloroquine-induced pruritus in rats via TRPV1 and CB1 receptors of spinal cord / 中国临床药理学与治疗学

AIM: To explore the possible mechanism of propofol in alleviating pruritus induced by subcutaneous injection of chloroquine in rats. METHODS: The pruritus model of chloroquine in SD rats was established and the administration time was determined. 18 rats with successful pruritus model induced by subcutaneous injection of chloroquine were randomly divided into NS group, I group and P group. Normal saline 80 μL/kg, fat emulsion 80 μL/kg and propofol 0.8 mg/kg were injected through internal jugular vein catheter 5 minutes after subcutaneous injection of chloroquine. Another 6 rats were randomly selected as group C, and the same volume of normal saline as the other 3 groups was injected subcutaneously in the back of the neck and through the internal jugular vein catheter. The rats were killed 16 minutes after the corresponding drugs were injected into the internal jugular vein. The expressions of TRPV1 and CB1 receptors in the spinal cord were detected by Western blot. RESULTS: Compared with NS group and I group, the expression level of TRPV1 receptor in the spinal cord of P group rats was significantly increased (P<0.01), while there was no statistically significant difference between C group, NS group, and I group; The expression level of CB1 receptor was significantly higher than that of group C, NS, and I (P<0.05), while there was no statistically significant difference between group C, NS, and I. CONCLUSION: Propofol can significantly alleviate pruritus caused by subcutaneous injection of chloroquine in rats, which may exert an antipruritic effect by increasing the expression of TRPV1 and CB1 receptors in the spinal cord of rats.

Research progress of 5-HT / 中国药理学通报

The serotonin 2A receptor(5-HT

Cannabinoid CB1 receptors are expressed in a sub-set of dopamine neurons and underlie cannabinoid modulation of DA release and DA-related behavior in mice / 中国药理学与毒理学杂志

OBJECTIVE Cannabinoids modulate do-pamine(DA)transmission and DA-related behavior,which has been thought to be mediated initially by acti-vation of cannabinoid CB1 receptors(CB1Rs)on GABA neurons.However,the cellular and receptor mechanisms underlying cannabinoids' psychoactive effects are not fully understood.The present study is to explore the pos-sible expression character of CB1Rs and elucidated the underlying mechanism of them.METHODS We took advantage of RNAscope in situ hybridization(ISH)assays and triple-staining assays to detect the CB1R-expressing neurons.We established an optical intracranial self-stimulation(OICSS)behavioral model by using opto-genetics to study dopaminergic reinforcement function.Natural and synthetic cannabinoids were used to study the function of CB1Rs.Conditional genetic depletion of CB1Rs and behavioral assay were performed to study the modulatory role of CB1Rs in DA-related behaviors.RESULTS We found that CB1Rs are also expressed in a subset of DA neurons and functionally underlie cannabi-noid action in male and female mice.ISH assays demon-strated CB1 mRNA in tyrosine hydroxylase(TH)-posi-tive DA neurons in the ventral tegmental area(VTA)and glutamate decarboxylase 1(GAD1)-positive GABA neu-rons.The CB1R expressing DA neurons were located mainly in the middle portion of the VTA with the number of CB1-TH colocalization progressively decreasing from the medial to the lateral VTA.Triple-staining assays indi-cated CB1R mRNA colocalization with both TH and vesicular glutamate transporter 2(VgluT2,a glutamate neuronal marker)in the medial VTA close to the midline of the brain.Optogenetic activation of this population of DA neurons was rewarding as assessed by OICSS.D9-tetrahydrocannabinol(D9-THC)or ACEA(a selective CB1R agonist)dose-dependently inhibited optical intra-cranial self-stimulation in DAT-Cre control mice,but not in conditional knockout mice with the CB1R gene absent in DA neurons.In addition,deletion of CB1Rs from DA neurons attenuated D9-THC-induced reduction in DA release in the NAc,locomotion,and anxiety.CONCLU-SION Our results indicated that CB1Rs are expressed in a subset of DA neurons that corelease DA and gluta-mate,and functionally underlie cannabinoid modulation of DA release and DA-related behavior.

Immune challenges upregulate the expression of cannabinoid receptors in cultured human odontoblasts and gingival fibroblasts / Los desafíos inmunológicos regulan la expresión de los receptores cannabinoides en cultivos de odontoblastos y fibroblastos gingivales humanos

ABSTRACT Odontoblasts and gingival fibroblasts play essential roles in the physiological and pathological processes of dental tissue. Cannabinoid receptors (CB1 and CB2) are involved in analgesia by modulating the función of calcium channels that inhibit the synthesis of some neurotransmitters. A better understanding of the physiology of these receptors would provide the possibility of using them as therapeutic targets in controlling dental pain. The aim of this study was to evaluate the presence and activity of cannabinoid receptors in human odontoblast-like cells (OLC) and human gingival fibroblasts (HGF). CB1 and CB2 transcription was analyzed by real-time PCR, proteins were detected by immunofluorescence, and functional cannabinoid receptors were evaluated by measuring intracellular calcium concentration after stimulation with cannabidiol (CBD) and pre-treatment with a CB1 antagonist, a CB2 inverse agonist and a TRPV1 antagonist. Transcripts for CB1 and CB2 were found in both odontoblasts and gingival fibroblasts. Cannabidiol induced an increase in [Ca2+]i in both cells types, but surprisingly, pre-treatment with selective cannabinoid antagonists attenuated this effect, suggesting a functional communication between specific cannabinoid receptors and other CBD target receptors. In conclusion, human odontoblasts and gingival fibroblasts express functional CB1 and CB2 cannabinoid receptors, which could be modulated to improve the treatment of pain or dental sensitivity.

RESUMEN Los odontoblastos y los fibroblastos gingivales desempeñan funciones esenciales en los procesos fisiológicos y patológicos de los tejidos dentales. Los receptores cannabinoides (CB1 y CB2) participan en la analgesia mediante la modulación de la función de canales de calcio que inhiben la síntesis de algunos neurotransmisores. Un mejor conocimiento de su fisiología abre la posibilidad de utilizar estos receptores como dianas terapéuticas en el control del dolor dental. Este trabajo tuvo como objetivo evaluar la presencia y la actividad de los receptores cannabinoides en células humanas similares a los odontoblastos (OLC) y en fibroblastos gingivales humanos (HGF). Se analizó la transcripción de CB1 y CB2 por PCR en tiempo real, la detección de las proteínas por inmunofluorescencia y se evaluaron los receptores cannabinoides funcionales midiendo las concentraciones de calcio intracelular, tras la estimulación con cannabidiol (CBD) y el pretratamiento con un antagonista de CB1, un agonista inverso de CB2 y un antagonista de TRPV1. Se encontraron mensajeros para CB1 y CB2 tanto en odontoblastos como en fibroblastos gingivales. El cannabidiol indujo un aumento de la [Ca2+]i en ambos tipos de células, pero sorprendentemente el pretratamiento con antagonistas cannabinoides selectivos atenuó este efecto, lo que sugiere una comunicación funcional entre receptores cannabinoides específicos y otros receptores diana del CBD. En conclusión, los odontoblastos humanos y los fibroblastos gingivales expresan receptores cannabinoides CB1 y CB2 funcionales, que podrían ser modulados para mejorar el tratamiento del dolor o la sensibilidad dental.

Cannabis and cannabinoids as an alternative remedy in metabolic syndrome

Abstract Metabolic syndrome (MetS), an epidemic defined as a group of interconnected physiological, biochemistry, clinical, and metabolic factors, directly increases the risk of cardiovascular disease, atherosclerosis, type 2 diabetes, and death. MetS therapy includes diet, physical exercise, and a poly-pharmacological intervention. Cannabis is mainly recognized for its recreational uses and has several medical applications for neurological diseases, due to its hypnotic, anxiolytic, antinociceptive, anti-inflammatory, and anticonvulsant activities. Although several clinical observations in Cannabis smokers suggest metabolic effects, its utility in metabolic disorders is unclear. This review aims to determine under what conditions Cannabis might be useful in the treatment of MetS. Cannabis contains 120 phytocannabinoids, of which Δ9-THC mediates its psychoactive effects. Cannabinoids exert biological effects through interactions with the endocannabinoid system, which modulates several physiologic and metabolic pathways through cannabinoid receptors (CB1/CB2). Signaling through both receptors inhibits neurotransmitter release. In general, endocannabinoid system stimulation in Cannabis smokers and Δ9-THC signaling through CB1 have been implicated in MetS development, obesity, and type 2 diabetes. In contrast, CB1 antagonists and non-psychotropic phytocannabinoids like cannabidiol reduce these effects through interactions with both cannabinoid and non-cannabinoid receptors. These pharmacological approaches represent a source of new therapeutic agents for MetS. However, more studies are necessary to support the therapeutic potential of Cannabis and cannabinoids in metabolic abnormalities

De novo venom gland transcriptomics of Calliophis bivirgata flaviceps: uncovering the complexity of toxins from the Malayan blue coral snake

The Malayan blue coral snake, Calliophis bivirgata flaviceps, is a medically important venomous snake in Southeast Asia. However, the complexity and diversity of its venom genes remain little explored. Methods: To address this, we applied high-throughput next-generation sequencing to profile the venom gland cDNA libraries of C. bivirgata flaviceps. The transcriptome was de novo assembled, followed by gene annotation, multiple sequence alignment and analyses of the transcripts. Results: A total of 74 non-redundant toxin-encoding genes from 16 protein families were identified, with 31 full-length toxin transcripts. Three-finger toxins (3FTx), primarily delta-neurotoxins and cardiotoxin-like/cytotoxin-like proteins, were the most diverse and abundantly expressed. The major 3FTx (Cb_FTX01 and Cb_FTX02) are highly similar to calliotoxin, a delta-neurotoxin previously reported in the venom of C. bivirgata. This study also revealed a conserved tyrosine residue at position 4 of the cardiotoxin-like/cytotoxin-like protein genes in the species. These variants, proposed as Y-type CTX-like proteins, are similar to the H-type CTX from cobras. The substitution is conservative though, preserving a less toxic form of elapid CTX-like protein, as indicated by the lack of venom cytotoxicity in previous laboratory and clinical findings. The ecological role of these toxins, however, remains unclear. The study also uncovered unique transcripts that belong to phospholipase A2 of Groups IA and IB, and snake venom metalloproteinases of PIII subclass, which show sequence variations from those of Asiatic elapids. Conclusion: The venom gland transcriptome of C. bivirgata flaviceps from Malaysia was de novo assembled and annotated. The diversity and expression profile of toxin genes provide insights into the biological and medical importance of the species.(AU)

Cannabinoid receptor-1 antagonism: a new perspective on treating a murine schistosomal liver fibrosis model

BACKGROUND Formation of schistosomal granulomata surrounding the ova can result in schistosomiasis-associated liver fibrosis (SSLF). The current standard of treatment is praziquantel (PZQ), which cannot effectively reverse SSLF. The role of the cannabinoid (CB) receptor family in liver fibrosis has recently been highlighted. OBJECTIVES This study aimed to assess the therapeutic effect of CB1 receptor antagonism in reversing SSLF in a murine model of Schistosoma mansoni infection. METHODS One hundred male Swiss albino mice were divided equally into five groups: healthy uninfected control (group I), infected control (group II), PZQ treated (group III), rimonabant (RIM) (SR141716, a CB1 receptor antagonist)-treated (group IV) and group V was treated with combined PZQ and RIM. Liver sections were obtained for histopathological examination, alpha-1 smooth muscle actin (α-SMA) immunostaining and assessment of CB1 receptor expression using real-time polymerase chain reaction (RT-PCR). FINDINGS The most effective reduction in fibrotic marker levels and granuloma load was achieved by combined treatment with PZQ+RIM (group V): CB1 receptor expression (H = 26.612, p < 0.001), number of α-SMA-positive cells (F = 57.086, p < 0.001), % hepatic portal fibrosis (F = 42.849, p < 0.001) and number of granulomata (F = 69.088, p < 0.001). MAIN CONCLUSIONS Combining PZQ with CB1 receptor antagonists yielded the best results in reversing SSLF. To our knowledge, this is the first study to test this regimen in S. mansoni infection.

Progress in research on the role of cannabinoid receptor 1 signaling pathway in epilepsy / 中华神经科杂志

Epilepsy,a group of chronic neurological disorders characterized by spontaneous and recurrent seizures and learning and memory impairments,results in transient brain dysfunction due to sudden abnormal discharge of brain neurons.The pathogenesis of epilepsy is very complicated and has not yet been fully elucidated.The imbalance between excitatory glutamate and inhibitory gamma-aminobutyric acid (GABA) neurotransmitters in the central nervous system and changes in ionic functions of N-methyl-D-aspartate receptors directly induce epileptic seizures.The endocannabinoid system plays an important role in retrograde synaptic transmission and exerts the anti-epileptic effect in cannabinoid receptor 1 (CBR1) dependent manner by regulating the synaptic transmission of glutamatergic and GABAergic neurons and homeostatsis of ionic channel function.Elucidating the specific mechanism of action of CBR1 signaling pathway in epilepsy,can provide an effective theoretical basis and novel drug's target for clinical treatment of epilepsy.

Roles of endocannabinoid system in treatment of neuropsychiatric diseases and regulation of arousal from general anesthesia / 中国药理学与毒理学杂志

The endocannabinoid(eCB)system has attracted attention for its role in various behav-ioral and brain functions, and as a therapeutic target in neuropsychiatric disease states,including anxiety disorders and other conditions resulting from dysfunctional responses to stress. Brain eCB signaling seems to harmonize appropriate behavioral responses, which are essential for the long-term viability and homeostasis of organisms. Dysregulation of eCB signaling contributes to negative emotional states and increases stress responsivity. A better understanding of the underlying neural cell popula-tions and neural circuitsregulation enables the development of therapeutic strategies to mitigate behav-ioral maladaptation and provides insight into the eCB influence on neural circuits of arousal from general anesthesia.This review focuses on recent evidence that has added a new layer of complexity to the idea of targeting the eCB system for therapeutic benefit in neuropsychiatric diseases and regulation of arousal after anesthesia.

Pharmacological characterizationof synthetic cannabinoid MAM-2201:radioligand binding and abuse-related effects / 中国药理学与毒理学杂志

OBJECTIVE Over 30% of all new psychoactive substances identified by the UN Office on Drugs and Crime in 2016 were synthetic cannabinoids. The recent emergence of MAM-2201 on the illicit market is troubling because this drug has no precedent in either the scientific or patent literature, and appears to be a novel compound developed specifically as a ″graymarket″ drug of abuse bystruc?turally combining the known synthetic cannabinoids JWH- 122 and AM- 2201. There is currently no published information regarding the pharmacology of MAM-2201. METHODS The present studies characterized cannabinoid-like effects of MAM-2201 in vitro (interactions with cannabinoid type 1 receptors [CB1Rs]) and in vivo (in mice and rats). RESULTS In a radioligand binding assay using [3H]CP55,940 in HEK cell membranes transfected with the CB1R, MAM-2201 (Ki=5.4 nmol·L- 1), had higher binding affinity than WIN 55,212-2 (Ki=80 nmol·L-1), and D9-THC (Ki=8.3 nmol·L-1). The Emax values for MAM-2201 and WIN 55,212-2 in an assay of agonist inhibition of forskolin-stimulated cAMP were 85% (EC50=0.45 nmol·L-1) and 95%, respectively, as compared with the D9-THC Emax of 74%. In mice, MAM-2201 (0.003-1.0 mg·kg-1, IP) produced dose-dependent cannabimimetic effects which were both more potent and more effective than those of D9-THC. MAM-2201 and D9-THC dose-dependently produced hypothermia:ED50=0.287 and 25.4 mg·kg-1, analgesia: ED50=0.125 and 29.4 mg·kg-1, and catalepsy: ED50=0.301 and 18.9 mg·kg-1 in adult male CD1 mice. Importantly, MAM-2201 also elicited convulsant effects at a dose of 1.0 mg·kg-1 in 8/8 murine subjects. In rats, MAM-2201 produced dose-dependent D9-THC-like intero?ceptive effects in subjects trained to discriminate 3.0 mg·kg-1 (IP) D9-THC from saline. CONCLUSION MAM-2201 binds CB1Rs with high affinity and agonist efficacy, and functions as a potent cannabinoid agonist in vivo across several complementary measures of cannabinoid activity in two rodent species.

Inibição do transito gastrintestinal por antipsicoticos: estudo experimental da clozapina

A eficácia da clozapina(CLZ)como um agente antipsicótico atípico foi reconhecida desde o início dos anos 1960, sendo ainda nos dias atuais a droga de escolha no tratamento de casos de esquizofrenia refratários a outros antipsicóticos. Dentre os efeitos adversos da CLZ, a constipaçãoé relatada com frequência, podendo progredir para obstruçãointestinal, necrose intestinal,sepse intrabdominale morte. O presente estudoavaliou o mecanismo de ação da CLZsobre a motilidade gastrintestinalatravés da análise da taxa de trânsito intestinal (TI) e da excreção de pelotas fecais em camundongos. Foram utilizados camundongos Swiss, machos, peso 25-30g, provenientes do Biotério Central da UFC e o projeto foi aprovado pela CEPA/UFC (Proc. No. 57/2014).As drogas utilizadas foram: CLZ (2,5; 5; 10; 20mg/kg), neostigmina (NEO, 1mg/kg i.p.), serotonina (5-HT, 10mg/kg v.o.), alilisitiocianato (AITC 10mg/kg v.o.), domperidona (DOM, 20mg/kg v.o.), L-NAME (80 mg/kg i.p.), naloxona (2mg/kg s.c.), glibenclamida (5mg/kg i.p.) e AM251 (1mg/kg i.p.).A administração oral de CLZ 10 e 20 mg/kgreduziusignificativamente(p<0,05) o transito gastrintestinal (TI) em relação ao veículoa partir desse resultado optou-se pela menor dose efetiva de CLZ sobre a função motora intestinal para as avaliações subsequentes...

Clozapine (CLZ)an atypicalantipsychotic agentrecognized for its efficacy since the early 1960s stillsnowadays the drug of choice in treating refractory schizophrenia cases to other antipsychotics. Among the adverse effects of CLZ, constipation, often reported, may progress to bowel obstruction, intestinal necrosis, intraabdominal sepsis and death. This study evaluated the mechanism of action of CLZ on gastrointestinal motility by analyzingthe intestinal transit rate (IT) and excretionof fecal pellets in mice. Animals usedwereSwiss males, weight 25-30g, from the UFC Central Animal Facility and the project approved by the CEPA / UFC (Proc. No. 57/2014). The drugs used were: CLZ (2.5, 5, 10, 20mg/kgp.o.), neostigmine (NEO 1mg /kg i.p.), serotonin (5-HT, 10mg/kg p.o.), alilisotiocianate(AITC 10mg/kg p.o.) , domperidone (DOM 20mg/kg p.o.), L-NAME (80 mg/kg i.p.), naloxone (2 mg/kg s.c.), glibenclamide (5 mg/kg i.p.) and AM251 (1 mg/kg i.p.). Oral administration of CLZ 10 and 20 mg/kg significantly (p <0.05) inhibited ITfrom the vehicle.Based on the results we decided forthe smallest effective dose of CLZ active on intestinal motor function(10mg/kg)for subsequent evaluations...

A spider derived peptide, PnPP-19, induces central antinociception mediated by opioid and cannabinoid systems

Background: Some peptides purified from the venom of the spider Phoneutria nigriventer have been identified as potential sources of drugs for pain treatment. In this study, we characterized the antinociceptive effect of the peptide PnPP-19 on the central nervous system and investigated the possible involvement of opioid and cannabinoid systems in its action mechanism. Methods: Nociceptive threshold to thermal stimulation was measured according to the tail-flick test in Swiss mice. All drugs were administered by the intracerebroventricular route.Results: PnPP-19 induced central antinociception in mice in the doses of 0.5 and 1 µg. The non-selective opioid receptor antagonist naloxone (2.5 and 5 µg), µ-opioid receptor antagonist clocinnamox (2 and 4 µg), δ-opioid receptor antagonist naltrindole (6 and 12 µg) and CB1 receptor antagonist AM251 (2 and 4 µg) partially inhibited the antinociceptive effect of PnPP-19 (1 µg). Additionally, the anandamide amidase inhibitor MAFP (0.2 µg), the anandamide uptake inhibitor VDM11 (4 µg) and the aminopeptidase inhibitor bestatin (20 µg) significantly enhanced the antinociception induced by a low dose of PnPP-19 (0.5 µg). In contrast, the κ-opioid receptor antagonist nor-binaltorphimine (10 µg and 20 µg) and the CB2 receptor antagonist AM630 (2 and 4 µg) do not appear to be involved in this effect. Conclusions: PnPP-19-induced central antinociception involves the activation of CB1 cannabinoid, µ- and δ-opioid receptors. Mobilization of endogenous opioids and cannabinoids might be required for the activation of those receptors, since inhibitors of endogenous substances potentiate the effect of PnPP-19. Our results contribute to elucidating the action of the peptide PnPP-19 in the antinociceptive pathway.(AU)

A spider derived peptide, PnPP-19, induces central antinociception mediated by opioid and cannabinoid systems

Some peptides purified from the venom of the spider Phoneutria nigriventer have been identified as potential sources of drugs for pain treatment. In this study, we characterized the antinociceptive effect of the peptide PnPP-19 on the central nervous system and investigated the possible involvement of opioid and cannabinoid systems in its action mechanism. Methods Nociceptive threshold to thermal stimulation was measured according to the tail-flick test in Swiss mice. All drugs were administered by the intracerebroventricular route. Results PnPP-19 induced central antinociception in mice in the doses of 0.5 and 1 g. The non-selective opioid receptor antagonist naloxone (2.5 and 5 g), -opioid receptor antagonist clocinnamox (2 and 4 g), -opioid receptor antagonist naltrindole (6 and 12 g) and CB1 receptor antagonist AM251 (2 and 4 g) partially inhibited the antinociceptive effect of PnPP-19 (1 g). Additionally, the anandamide amidase inhibitor MAFP (0.2 g), the anandamide uptake inhibitor VDM11 (4 g) and the aminopeptidase inhibitor bestatin (20 g) significantly enhanced the antinociception induced by a low dose of PnPP-19 (0.5 g). In contrast, the -opioid receptor antagonist nor-binaltorphimine (10 g and 20 g) and the CB2 receptor antagonist AM630 (2 and 4 g) do not appear to be involved in this effect. Conclusions PnPP-19-induced central antinociception involves the activation of CB1 cannabinoid, - and -opioid receptors. Mobilization of endogenous opioids and cannabinoids might be required for the activation of those receptors, since inhibitors of endogenous substances potentiate the effect of PnPP-19. Our results contribute to elucidating the action of the peptide PnPP-19 in the antinociceptive pathway.

A Cannabinoid Receptor Agonist N-Arachidonoyl Dopamine Inhibits Adipocyte Differentiation in Human Mesenchymal Stem Cells

Endocannabinoids can affect multiple cellular targets, such as cannabinoid (CB) receptors, transient receptor potential cation channel, subfamily V, member 1 (TRPV1) and peroxisome proliferator-activated receptor gamma (PPARgamma). The stimuli to induce adipocyte differentiation in hBM-MSCs increase the gene transcription of the CB1 receptor, TRPV1 and PPARgamma. In this study, the effects of three endocannabinoids, N-arachidonoyl ethanolamine (AEA), N-arachidonoyl dopamine (NADA) and 2-arachidonoyl glycerol (2-AG), on adipogenesis in hBM-MSCs were evaluated. The adipocyte differentiation was promoted by AEA whereas inhibited by NADA. No change was observed by the treatment of non-cytotoxic concentrations of 2-AG. The difference between AEA and NADA in the regulation of adipogenesis is associated with their effects on PPARgamma transactivation. AEA can directly activate PPARgamma. The effect of AEA on PPARgamma in hBM-MSCs may prevail over that on the CB1 receptor mediated signal transduction, giving rise to the AEA-induced promotion of adipogenesis. In contrast, NADA had no effect on the PPARgamma activity in the PPARgamma transactivation assay. The inhibitory effect of NADA on adipogenesis in hBM-MSCs was reversed not by capsazepine, a TRPV1 antagonist, but by rimonabant, a CB1 antagonist/inverse agonist. Rimonabant by itself promoted adipogenesis in hBM-MSCs, which may be interpreted as the result of the inverse agonism of the CB1 receptor. This result suggests that the constantly active CB1 receptor may contribute to suppress the adipocyte differentiation of hBM-MSCs. Therefore, the selective CB1 agonists that are unable to affect cellular PPARgamma activity inhibit adipogenesis in hBM-MSCs.

Peripherally restricted CB1 receptor antagonist: Research advances / 国际药学研究杂志

Cannabinoid 1 receptor (CB1R) is one of most important targets for the treatment of obesity. However, the clinical application of CB1R antagonist rimonabant is restricted because of the central nervous system-related unwanted liabilities. Peripherally restricted CB1R antagonist with limited blood-brain-barrier penetration may maintain the antiobesity efficacy of rimonabant without unwanted side effects. This strategy has become the new hot spot for the development of antiobesity drugs. In this paper, we review the recent progress in peripherally restricted CB1 receptor antagonist.

Effects of Rimonabant on Cannabinoid Receptor 1 andα-Smooth Muscle Actin in C57 Mice with Experimental Hepatic Fibrosis / 天津医药

Objective To study the effect of rimonabant, cannabinoid receptor 1(CB1) antagonist, on the expressions of CB1 andα-smooth muscle actin (α-SMA) in C57 mice with experimental hepatic fibrosis, and their mechanisms in liver fibrosis progression thereof. Methods Thirty C57 mice were randomly divided into three groups, normal control group, mod-el control group and model+rimonabant group, 10 mice for each group. The mouse model of experimental hepatic fibrosis was induced by intraperitoneal injection with 10%CCl4 for two weeks. The normal saline was delivered by gavage daily in normal control group and model control group. Rimonabant was given to mice in model+rimonabant group. Mice were sacri-ficed at the end of eight weeks. Samples of liver tissue were collected. The expressions of CB1 andα-SMA in liver tissue of mice were observed by immunohistochemical staining. The score of fibrosis stage (S) in liver tissue was also analyzed. Re-sults The positive expressions of CB1 andα-SMA and the score S were significantly higher in model control group and model+rimonabant group than those in normal control group (P<0.05). The positive expressions of CB1 andα-SMA and the score S were significantly lower in rimonabant group than those in model control group (P<0.05). There were positive corre-lations in CB1,α-SMA and S scores between normal control group, model control group and model+rimonabant group (P<0.05). Conclusion The activation of CB1 can promote the formation of liver fibrosis. The anti-fibrotic effect of rimonabant, CB1 antagonist, related with the inhibiting of the proliferation and activation of hepatic stellate cells (HSC), and the inhibit-ing of the expression of CB1.

Peripherally restricted CB1 receptor antagonist:research advances / 国际药学研究杂志

Cannabinoid 1 receptor (CB1R) is one of most important targets for the treatment of obesity. However, the clinical application of CB1R antagonist rimonabant is restricted because of the central nervous system-related unwanted liabilities. Peripherally restricted CB1R antagonist with limited blood-brain-barrier penetration may maintain the antiobesity efficacy of rimonabant without unwanted side effects. This strategy has become the new hot spot for the development of antiobesity drugs. In this paper, we review the recent progress in peripherally restricted CB1 receptor antagonist .

Dependence Potential of the Synthetic Cannabinoids JWH-073, JWH-081, and JWH-210: In Vivo and In Vitro Approaches

Synthetic cannabinoids (CBs) such as the JWH series have caused social problems concerning their abuse liability. Because the JWH series produces euphoric and hallucinogenic effects, they have been distributed illegally under street names such as "Spice" and "Smoke". Many countries including Korea have started to schedule some of the JWH series compounds as controlled substances, but there are a number of JWH series chemicals that remain uncontrolled by law. In this study, three synthetic CBs with different binding affinities to the CB1 receptor (JWH-073, 081, and 210) and Delta9-tetrahydrocannabinol (Delta9-THC) were evaluated for their potential for psychological dependence. The conditioned place preference test (unbiased method) and self-administration test (fixed ratio of 1) using rodents were conducted. Ki values of the three synthetic cannabinoids were calculated as supplementary data using a receptor binding assay and overexpressed CB1 protein membranes to compare dependence potential with CB1 receptor binding affinity. All mice administered JWH-073, 081, or 210 showed significantly increased time spent at unpreferred space in a dose-dependence manner in the conditioned place preference test. In contrast, all tested substances except Delta9-THC showed aversion phenomenon at high doses in the conditioned place preference test. The order of affinity to the CB1 receptor in the receptor binding assay was JWH-210 > JWH-081 >> JWH-073, which was in agreement with the results from the conditioned place preference test. However, no change in self-administration was observed. These findings suggest the possibility to predict dependence potential of synthetic CBs through a receptor binding assay at the screening level.