RESUMO
OBJECTIVE: In this study, the effects of leptin, cannabinoid-1 (CB1) receptor agonist ACEA and antagonist AM251, and the interactions between leptin and CB1 receptor agonist/antagonist on oxidant and antioxidant enzymes in the cerebrum, cerebellum, and pedunculus cerebri tissue samples were investigated in the penicillin-induced epileptic model. METHODS: Male Wistar albino rats (n=56) were included in this study. In anesthetized animals, 500 IU penicillin-G potassium was injected into the cortex to induce epileptiform activity. Leptin (1 µg), ACEA (7.5 µg), AM251 (0.25 µg), and the combinations of the leptin+ACEA and leptin+AM251 were administered intracerebroventricularly (i.c.v.) after penicillin injections. Malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPx) levels were measured in the cerebral tissue samples and plasma with the ELISA method. RESULTS: MDA levels increased, while SOD and GPx levels decreased after penicillin injection in the cerebrum and cerebellum. The efficacy of penicillin on SOD, MDA and GPx levels was further enhanced after leptin or AM251 injections. Whereas, ACEA decreased the MDA levels and increased GPx levels compared with the penicillin group. Administration of AM251+leptin did not change any oxidation parameter compared with the AM251. Furthermore, co-administration of ACEA and leptin significantly increased oxidative stress compared with the ACEA-treated group by increasing MDA and decreasing GPx levels. CONCLUSION: It was concluded that leptin reversed the effect of ACEA on oxidative stress. Co-administration of AM251 and leptin did not change oxidative stress compared with the AM251-treated group suggesting AM251 and leptin affect oxidative stress using the same pathways.
Assuntos
Epilepsia , Leptina , Malondialdeído , Piperidinas , Pirazóis , Ratos Wistar , Receptor CB1 de Canabinoide , Superóxido Dismutase , Animais , Leptina/farmacologia , Masculino , Receptor CB1 de Canabinoide/agonistas , Epilepsia/tratamento farmacológico , Epilepsia/induzido quimicamente , Malondialdeído/análise , Superóxido Dismutase/metabolismo , Superóxido Dismutase/análise , Piperidinas/farmacologia , Pirazóis/farmacologia , Glutationa Peroxidase/metabolismo , Glutationa Peroxidase/análise , Ácidos Araquidônicos/farmacologia , Ratos , Estresse Oxidativo/efeitos dos fármacos , Modelos Animais de Doenças , Penicilinas , Cerebelo/efeitos dos fármacos , Cerebelo/metabolismo , Cérebro/efeitos dos fármacos , Cérebro/metabolismo , Ensaio de Imunoadsorção Enzimática , Agonistas de Receptores de Canabinoides/farmacologiaRESUMO
Mitochondrial dysfunction plays a key role in the development of neurodegenerative disorders. In contrast, the regulation of the endocannabinoid system has been shown to promote neuroprotection in different neurotoxic paradigms. The existence of an active form of the cannabinoid receptor 1 (CB1R) in mitochondrial membranes (mitCB1R), which might exert its effects through the same signaling mechanisms as the cell membrane CB1R, has been shown to regulate mitochondrial activity. Although there is evidence suggesting that some cannabinoids may induce protective effects on isolated mitochondria, substantial evidence on the role of cannabinoids in mitochondria remains to be explored. In this work, we developed a toxic model of mitochondrial dysfunction induced by exposure of brain mitochondria to the succinate dehydrogenase inhibitor 3-nitropropionic acid (3-NP). Mitochondria were also pre-incubated with the endogenous agonist anandamide (AEA) and the synthetic CB1R agonist WIN 55212-2 to evaluate their protective effects. Mitochondrial reduction capacity, reactive oxygen species (ROS) formation, and mitochondrial swelling were assessed as toxic markers. While 3-NP decreased the mitochondrial reduction capacity and augmented mitochondrial ROS formation and swelling, both AEA and WIN 55212-2 ameliorated these toxic effects. To explore the possible involvement of mitCB1R activation on the protective effects of AEA and WIN 55212-2, mitochondria were also pre-incubated in the presence of the selective CB1R antagonist AM281, which completely reverted the protective effects of the cannabinoids to levels similar to those evoked by 3-NP. These results show partial protective effects of cannabinoids, suggesting that mitCB1R activation may be involved in the recovery of compromised mitochondrial activity, related to reduction of ROS formation and further prevention of mitochondrial swelling.
Assuntos
Ácidos Araquidônicos , Benzoxazinas , Encéfalo , Endocanabinoides , Mitocôndrias , Morfolinas , Naftalenos , Fármacos Neuroprotetores , Nitrocompostos , Alcamidas Poli-Insaturadas , Propionatos , Ratos Wistar , Espécies Reativas de Oxigênio , Animais , Nitrocompostos/toxicidade , Propionatos/farmacologia , Propionatos/toxicidade , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Endocanabinoides/metabolismo , Endocanabinoides/farmacologia , Benzoxazinas/farmacologia , Ácidos Araquidônicos/farmacologia , Morfolinas/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Alcamidas Poli-Insaturadas/farmacologia , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Masculino , Fármacos Neuroprotetores/farmacologia , Naftalenos/farmacologia , Dilatação Mitocondrial/efeitos dos fármacos , Ratos , Receptor CB1 de Canabinoide/metabolismoRESUMO
Cannabinoids regulate analgesia, which has aroused much interest in identifying new pharmacological therapies in the management of refractory pain. Voltage-gated Na+ channels (Navs) play an important role in inflammatory and neuropathic pain. In particular, Nav1.9 is involved in nociception and the understanding of its pharmacology has lagged behind because it is difficult to express in heterologous systems. Here, we utilized the chimeric channel hNav1.9_C4, that comprises the extracellular and transmembrane domains of hNav1.9, co-expressed with the ß1 subunit on CHO-K1 cells to characterize the electrophysiological effects of ACEA, a synthetic surrogate of the endogenous cannabinoid anandamide. ACEA induced a tonic block, decelerated the fast inactivation, markedly shifted steady-state inactivation in the hyperpolarized direction, decreasing the window current and showed use-dependent block, with a high affinity for the inactivated state (ki = 0.84 µM). Thus, we argue that ACEA possess a local anaesthetic-like profile. To provide a mechanistic understanding of its mode of action at the molecular level, we combined induced fit docking with Monte Carlo simulations and electrostatic complementarity. In agreement with the experimental evidence, our computer simulations revealed that ACEA binds Tyr1599 of the local anaesthetics binding site of the hNav1.9, contacting residues that bind cannabinol (CBD) in the NavMs channel. ACEA adopted a conformation remarkably similar to the crystallographic conformation of anandamide on a non-homologous protein, obstructing the Na+ permeation pathway below the selectivity filter to occupy a highly conserved binding pocket at the intracellular side. These results describe a mechanism of action, possibly involved in cannabinoid analgesia.
Assuntos
Ácidos Araquidônicos , Canabinoides , Humanos , Ácidos Araquidônicos/farmacologia , Canais de Sódio , Dor , Anestésicos Locais , Bloqueadores dos Canais de Sódio/farmacologiaRESUMO
Lipid and cholinergic mediators are inflammatory regulators, but their role in the immunopathology of COVID-19 is still unclear. Here, we used human blood and tracheal aspirate (TA) to investigate whether acetylcholine (Ach), fatty acids (FAs), and their derived lipid mediators (LMs) are associated with COVID-19 severity. First, we analyzed the perturbation profile induced by SARS-CoV-2 infection in the transcriptional profile of genes related to the ACh and FA/LM pathways. Blood and TA were used for metabolomic and lipidomic analyses and for quantification of leukocytes, cytokines, and ACh. Differential expression and coexpression gene network data revealed a unique transcriptional profile associated with ACh and FA/LM production, release, and cellular signaling. Transcriptomic data were corroborated by laboratory findings: SARS-CoV-2 infection increased plasma and TA levels of arachidonic acid, 5-hydroxy-6E,8Z,11Z,14Z-eicosatetraenoic acid, 11-hydroxy-5Z,8Z,12E,14Z-eicosatetraenoic acid, and ACh. TA samples also exhibited high levels of PGE2, thromboxane B2, 12-oxo-5Z,8Z,10E,14Z-eicosatetraenoic acid, and 6-trans-leukotriene B4 Bioinformatics and experimental approaches demonstrated robust correlation between transcriptional profile in Ach and FA/LM pathways and parameters of severe COVID-19. As expected, the increased neutrophil-to-lymphocyte ratio, neutrophil counts, and cytokine levels (IL-6, IL-10, IL-1ß, and IL-8) correlated with worse clinical scores. Glucocorticoids protected severe and critical patients and correlated with reduced Ach levels in plasma and TA samples. We demonstrated that pulmonary and systemic hyperinflammation in severe COVID-19 are associated with high levels of Ach and FA/LM. Glucocorticoids favored the survival of patients with severe/critical disease, and this effect was associated with a reduction in ACh levels.
Assuntos
Acetilcolina , COVID-19 , Ácido Araquidônico , Ácidos Araquidônicos/farmacologia , Ácidos Graxos , Glucocorticoides , Humanos , SARS-CoV-2RESUMO
BACKGROUND: Curcumin is one of the compounds present in plants of the genus Curcuma sp., being very used not only as condiment but also with medicinal purposes. As an analgesic, papers highlight the efficacy of curcumin in the treatment of various types of pain. AIMS: In this study we evaluated the peripheral antinociceptive effect of curcumin and by which mechanisms this effect is induced. MAIN METHODS: The mice paw pressure test was used on animals which had increased pain sensitivity by intraplantar injection of carrageenan. All the drugs were administered in the right hind paw. KEY FINDINGS: Curcumin was administered to the right hind paw animals induced antinociceptive effect. Non -selective antagonist of opioid receptors naloxone reverted the antinociceptive effect induced by curcumin. Selective antagonists for µ, δ and κ opioid receptors clocinnamox, naltrindole and nor- binaltorphimine, respectively, reverted the antinociceptive effect induced by curcumin. Bestatin, enkephalinases inhibitor that degrade peptides opioids, did not change the nociceptive response. Selective antagonists for CB1 and CB2 cannabinoid receptors, AM251 and AM630, respectively, reversed the antinociceptive effect induced by curcumin. The MAFP inhibitor of the enzyme FAAH which breaks down anandamide, JZL184, enzyme inhibitor MAGL which breaks down the 2-AG, as well as the VDM11 anandamide reuptake inhibitor potentiated the antinociceptive effect of curcumin. SIGNIFICANCE: These results suggest that curcumin possibly peripheral antinociception induced by opioid and cannabinoid systems activation and possibly for endocannabinoids and opioids release.
Assuntos
Analgésicos/uso terapêutico , Agonistas de Receptores de Canabinoides/uso terapêutico , Curcumina/uso terapêutico , Hiperalgesia/tratamento farmacológico , Hiperalgesia/metabolismo , Receptores Opioides/metabolismo , Analgésicos/farmacologia , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Anti-Inflamatórios não Esteroides/uso terapêutico , Ácidos Araquidônicos/farmacologia , Ácidos Araquidônicos/uso terapêutico , Agonistas de Receptores de Canabinoides/farmacologia , Carragenina/toxicidade , Cinamatos/farmacologia , Curcumina/farmacologia , Relação Dose-Resposta a Droga , Endocanabinoides/farmacologia , Endocanabinoides/uso terapêutico , Hiperalgesia/induzido quimicamente , Masculino , Camundongos , Derivados da Morfina/farmacologia , Antagonistas de Entorpecentes/farmacologia , Dor/induzido quimicamente , Dor/tratamento farmacológico , Dor/metabolismo , Alcamidas Poli-Insaturadas/farmacologia , Alcamidas Poli-Insaturadas/uso terapêuticoRESUMO
The activation of the human cannabinoid receptor type II (CB2R) is known to mediate analgesic and anti-inflammatory processes without the central adverse effects related to cannabinoid receptor type I (CB1R). In this work we describe the synthesis and evaluation of a novel series of N-aryl-2-pyridone-3-carboxamide derivatives tested as human cannabinoid receptor type II (CB2R) agonists. Different cycloalkanes linked to the N-aryl pyridone by an amide group displayed CB2R agonist activity as determined by intracellular [cAMP] levels. The most promising compound 8d exhibited a non-toxic profile and similar potency (EC50 = 112 nM) to endogenous agonists Anandamide (AEA) and 2-Arachidonoylglycerol (2-AG) providing new information for the development of small molecules activating CB2R. Molecular docking studies showed a binding pose consistent with two structurally different agonists WIN-55212-2 and AM12033 and suggested structural requirements on the pyridone substituents that can satisfy the orthosteric pocket and induce an agonist response. Our results provide additional evidence to support the 2-pyridone ring as a suitable scaffold for the design of CB2R agonists and represent a starting point for further optimization and development of novel compounds for the treatment of pain and inflammation.
Assuntos
Agonistas de Receptores de Canabinoides/química , Agonistas de Receptores de Canabinoides/farmacologia , Piridonas/química , Receptor CB2 de Canabinoide/agonistas , Animais , Ácidos Araquidônicos/química , Ácidos Araquidônicos/farmacologia , Benzoxazinas/química , Benzoxazinas/farmacologia , Sítios de Ligação , Células CHO , Agonistas de Receptores de Canabinoides/síntese química , Sobrevivência Celular/efeitos dos fármacos , Cricetulus , AMP Cíclico/metabolismo , Avaliação Pré-Clínica de Medicamentos , Endocanabinoides/química , Endocanabinoides/farmacologia , Glicerídeos/química , Glicerídeos/farmacologia , Células HL-60 , Células Hep G2 , Humanos , Simulação de Acoplamento Molecular , Morfolinas/química , Morfolinas/farmacologia , Naftalenos/química , Naftalenos/farmacologia , Alcamidas Poli-Insaturadas/química , Alcamidas Poli-Insaturadas/farmacologia , Piridonas/farmacologia , Receptor CB2 de Canabinoide/química , Receptor CB2 de Canabinoide/genética , Receptor CB2 de Canabinoide/metabolismo , Relação Estrutura-AtividadeRESUMO
Tardive dyskinesia (TD) is a side effect associated with the long-term use of certain antipsychotics. Considering the modulatory role of the endocannabinoid system upon dopaminergic neurotransmission, the present study tested the hypothesis that increasing endocannabinoid (anandamide and 2-arachidonoylglycerol) levels attenuates haloperidol-induced TD (vacuous chewing movements, VCMs) in male Wistar rats. The animals received administration of chronic haloperidol (38 mg/kg; 29 days) followed by acute FAAH (URB597, 0.1-0.5 mg/kg) or MAGL (JZL184, 1-10 mg/kg) inhibitors before VCM quantification. The underlying mechanisms were evaluated by pre-treatments with a CB1 receptor antagonist (AM251, 1 mg/kg) or a TRPV1 channel blocker (SB366791, 1 mg/kg). Moreover, CB1 receptor expression was evaluated in the striatum of high-VCM animals. As expected, haloperidol induced VCMs only in a subset of rats. Either FAAH or MAGL inhibition reduced VCMs. These effects were prevented by CB1 receptor antagonism, but not by TRPV1 blockage. Remarkably, CB1 receptor expression was increased high-VCM rats, with a positive correlation between the levels of CB1 expression and the number of VCMs. In conclusion, increasing endocannabinoid levels results in CB1 receptor-mediated protection against haloperidol-induced TD in rats. The increased CB1 receptor expression after chronic haloperidol treatment suggests a counter-regulatory protective mechanism.
Assuntos
Agonistas de Receptores de Canabinoides/farmacologia , Discinesia Induzida por Medicamentos/tratamento farmacológico , Endocanabinoides/metabolismo , Haloperidol/efeitos adversos , Animais , Antipsicóticos/efeitos adversos , Ácidos Araquidônicos/farmacologia , Antagonistas de Receptores de Canabinoides/farmacologia , Corpo Estriado/efeitos dos fármacos , Modelos Animais de Doenças , Discinesia Induzida por Medicamentos/metabolismo , Endocanabinoides/farmacologia , Glicerídeos/farmacologia , Masculino , Mastigação/efeitos dos fármacos , Alcamidas Poli-Insaturadas/farmacologia , Ratos , Ratos Wistar , Receptor CB1 de Canabinoide/metabolismo , Canais de Cátion TRPV/metabolismo , Discinesia Tardia/tratamento farmacológico , Discinesia Tardia/metabolismoRESUMO
PURPOSE: Hypertensive lesions induce alterations at hemodynamic, peripheral, and central levels. Anandamide (N-arachidonoylethanolamine; AEA) protects neurons from inflammatory damage, but its free administration may cause central adverse effects. AEA controlled release by nanoformulations could reduce/eliminate its side effects. The present study aimed to evaluate the effects of nanoformulated AEA (nf-AEA) on systolic blood pressure (SBP), behavior, and central/peripheral inflammatory, oxidative, and apoptotic state in spontaneously hypertensive rats (SHR). MATERIALS/METHODS: Male rats were used, both Wistar Kyoto (WKY) and SHR (n â= â10 per group), with/without treatment with nf-AEA (obtained by electrospraying) at a weekly dose of 5 âmg/kg IP for 4 weeks. SBP was measured and behavioral tests were performed. Inflammatory/oxidative markers were quantified at the central (brain cortex) and peripheral (serum) level. RESULTS: SHR showed hyperactivity, low anxiety, and high concentrations of central/peripheral inflammatory/oxidative markers, also higher apoptosis of brain cortical cells compared to WKY. As opposed to this group, treatment with nf-AEA in SHR significantly reduced SBP, peripheral/central inflammatory/oxidative makers, and central apoptosis. Nf-AEA also increased neuroprotective mechanisms mediated by intracellular heat shock protein 70 (Hsp70), which were attenuated in untreated SHR. Additionally, nf-AEA reversed the abnormal behaviors observed in SHR without producing central adverse effects. CONCLUSIONS: Our results suggest protective properties of nf-AEA, both peripherally and centrally, through a signaling pathway that would involve the type I angiotensin II receptor, Wilms tumor transcription factor 1, Hsp70, and iNOS. Considering non-nf-AEA limitations, this nanoformulation could contribute to the development of new antihypertensive and behavioral disorder treatments associated with neuroinflammation.
Assuntos
Anti-Hipertensivos/farmacologia , Ácidos Araquidônicos/farmacologia , Sistema Nervoso Central/efeitos dos fármacos , Endocanabinoides/farmacologia , Hemodinâmica , Hipertensão/tratamento farmacológico , Nanopartículas/química , Sistema Nervoso Periférico/efeitos dos fármacos , Alcamidas Poli-Insaturadas/farmacologia , Animais , Anti-Hipertensivos/administração & dosagem , Anti-Hipertensivos/química , Ácidos Araquidônicos/administração & dosagem , Ácidos Araquidônicos/química , Pressão Sanguínea , Endocanabinoides/administração & dosagem , Endocanabinoides/química , Hipertensão/metabolismo , Hipertensão/patologia , Masculino , Nanopartículas/administração & dosagem , Estresse Oxidativo , Alcamidas Poli-Insaturadas/administração & dosagem , Alcamidas Poli-Insaturadas/química , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Transdução de SinaisRESUMO
The purpose of this study was to investigate whether the panicolyticlike effect of different doses of anandamide microinjected into the anterior hypothalamus (AH) follows the same pattern of a bellshaped doseresponse curve observed with the same dose treatment in dorsomedial and ventromedial hypothalamus. We investigated this assumption by administering the cannabinoid and vanilloid receptor agonist anandamide into the anterior hypothalamus of mice and exposing them to the real threatening situation by using our experimental model based on confrontations between rodents and wild snakes. Our findings showed a gradual decay of response, with a significant attenuation of the panic attacklike responses with anandamide at the highest dose but no effect was found after anandamide at the lowest or intermediate doses. An immunohistochemical procedure showed a lower degree of TRPV1 receptor and moderate to higher degree of Cb1 receptors in anterior hypothalamus. In conclusion, the pattern of doseresponse curve of anandamide microinjected in the AH does not seem to be the same classical pattern compared with other hypothalamic nuclei.
Assuntos
Ácidos Araquidônicos/farmacologia , Bicuculina/farmacologia , Endocanabinoides/farmacologia , Reação de Fuga/efeitos dos fármacos , Hipotálamo Anterior/efeitos dos fármacos , Alcamidas Poli-Insaturadas/farmacologia , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Receptor CB1 de Canabinoide/efeitos dos fármacos , Canais de Cátion TRPV/efeitos dos fármacosRESUMO
Evidence indicates that periaqueductal gray matter (PAG) plays an important role in defensive responses and pain control. The activation of cannabinoid type-1 (CB1) or mu-opioid (MOR) receptors in the dorsal region of this structure (dPAG) inhibits fear and facilitates antinociception induced by different aversive stimuli. However, it is still unknown whether these two receptors work cooperatively in order to achieve these inhibitory actions. This study investigated the involvement and a likely interplay between CB1 and MOR receptors localized into the dPAG on the regulation of fear-like defensive responses and antinociception (evaluated in tail-flick test) evoked by dPAG chemical stimulation with N-methyl-d-aspartate (NMDA). Before the administration of NMDA, animals were first intra-dPAG injected with the CB1 agonist ACEA (0.5 pmol), or with the MOR agonist DAMGO (0.5 pmol) in combination with the respective antagonists AM251 (CB1 antagonist, 100 pmol) or CTOP (MOR antagonist, 1 nmol). To investigate the interplay between these receptors, microinjection of CTOP was combined with ACEA, or microinjection of AM251 was combined with DAMGO. Our results showed that both the intra-PAG treatments with ACEA or DAMGO inhibited NMDA-induced freezing expression, whereas only the treatment with DAMGO increased antinociception induced with NMDA, which are completely blocked by its respective antagonists. Interestingly, the inhibitory effects of ACEA or DAMGO on freezing was blocked by CTOP and AM251, respectively, indicating a functional interaction between these two receptors in the mediation of defensive behaviors. However, this cooperative interaction was not observed during the NMDA-induced antinociception. Our findings indicate that there is a cooperative action between the MOR and CB1 receptors within the dPAG and it is involved in the mediation of NMDA-induced defensive responses. Additionally, the MORs into the dPAG are involved in the modulation of the antinociceptive effects that follow a fear-like defense-reaction induced by dPAG chemical stimulation with NMDA.