RESUMEN
PURPOSE: Sex differences play a crucial role in understanding vulnerability to opioid addiction, yet there have been limited preclinical investigations of this effect during the transition from adolescence to adulthood. The present study compared the behaviors of male and female rodents in response to fentanyl treatment and targeted molecular correlates in the striatum and medial prefrontal cortex. MATERIALS AND METHODS: Thirty adolescent C57BL/6J mice underwent a 1-week fentanyl treatment with an escalating dose. In addition to evaluating locomotor activity and anxiety-related parameters, we also assessed naloxone-induced fentanyl acute withdrawal jumps. We employed real-time quantitative PCR (qPCR) to assess overall gene expression of dopaminergic receptors (Drd1, Drd2, Drd4 and Drd5) and the µ-opioid receptor Oprm1. The levels of epigenetic base modifications including 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) were assessed on CpG islands of relevant genes. RESULTS: Females had higher locomotor activity than males after chronic fentanyl treatment, and they exhibited higher fentanyl withdrawal jumping behavior induced by naloxone. Females also presented lower Drd4 gene expression and DNA methylation (5mC + 5hmC) in the striatum. We found that locomotor activity and fentanyl withdrawal jumps were negatively correlated with Drd4 methylation and gene expression in the striatum, respectively. CONCLUSIONS: The findings suggested that female mice displayed heightened sensitivity to the effects of fentanyl treatment during the transition from adolescence to adulthood. This effect may be associated with molecular alterations related to the Drd4 gene.
Asunto(s)
Fentanilo , Ratones Endogámicos C57BL , Receptores Opioides mu , Caracteres Sexuales , Animales , Fentanilo/farmacología , Masculino , Femenino , Receptores Opioides mu/genética , Receptores Opioides mu/metabolismo , Ratones , Metilación de ADN/efectos de los fármacos , Analgésicos Opioides/farmacología , Cuerpo Estriado/metabolismo , Cuerpo Estriado/efectos de los fármacos , Locomoción/efectos de los fármacos , Corteza Prefrontal/efectos de los fármacos , Corteza Prefrontal/metabolismo , Receptores Dopaminérgicos/genética , Receptores Dopaminérgicos/metabolismo , Naloxona/farmacología , Conducta Animal/efectos de los fármacos , Síndrome de Abstinencia a Sustancias/genética , Síndrome de Abstinencia a Sustancias/metabolismo , Epigénesis Genética/efectos de los fármacosRESUMEN
BACKGROUND: Morphine is an opiate commonly used in the treatment of moderate to severe pain. However, prolonged administration can lead to physical dependence and strong withdrawal symptoms upon cessation of morphine use. These symptoms can include anxiety, irritability, increased heart rate, and muscle cramps, which strongly promote morphine use relapse. The morphine-induced increases in neuroinflammation, brain oxidative stress, and alteration of glutamate levels in the hippocampus and nucleus accumbens have been associated with morphine dependence and a higher severity of withdrawal symptoms. Due to its rich content in potent anti-inflammatory and antioxidant factors, secretome derived from human mesenchymal stem cells (hMSCs) is proposed as a preclinical therapeutic tool for the treatment of this complex neurological condition associated with neuroinflammation and brain oxidative stress. METHODS: Two animal models of morphine dependence were used to evaluate the therapeutic efficacy of hMSC-derived secretome in reducing morphine withdrawal signs. In the first model, rats were implanted subcutaneously with mini-pumps which released morphine at a concentration of 10 mg/kg/day for seven days. Three days after pump implantation, animals were treated with a simultaneous intravenous and intranasal administration of hMSC-derived secretome or vehicle, and withdrawal signs were precipitated on day seven by i.p. naloxone administration. In this model, brain alterations associated with withdrawal were also analyzed before withdrawal precipitation. In the second animal model, rats voluntarily consuming morphine for three weeks were intravenously and intranasally treated with hMSC-derived secretome or vehicle, and withdrawal signs were induced by morphine deprivation. RESULTS: In both animal models secretome administration induced a significant reduction of withdrawal signs, as shown by a reduction in a combined withdrawal score. Secretome administration also promoted a reduction in morphine-induced neuroinflammation in the hippocampus and nucleus accumbens, while no changes were observed in extracellular glutamate levels in the nucleus accumbens. CONCLUSION: Data presented from two animal models of morphine dependence suggest that administration of secretome derived from hMSCs reduces the development of opioid withdrawal signs, which correlates with a reduction in neuroinflammation in the hippocampus and nucleus accumbens.
Asunto(s)
Células Madre Mesenquimatosas , Dependencia de Morfina , Síndrome de Abstinencia a Sustancias , Humanos , Ratas , Animales , Morfina , Dependencia de Morfina/tratamiento farmacológico , Administración Intranasal , Enfermedades Neuroinflamatorias , Secretoma , Naloxona/farmacología , Síndrome de Abstinencia a Sustancias/tratamiento farmacológico , Glutamatos , Antagonistas de Narcóticos/farmacologíaRESUMEN
Chronic opioid intake leads to several brain changes involved in the development of dependence, whereby an early hedonistic effect (liking) extends to the need to self-administer the drug (wanting), the latter being mostly a prefrontal-striatal function. The development of animal models for voluntary oral opioid intake represents an important tool for identifying the cellular and molecular alterations induced by chronic opioid use. Studies mainly in humans have shown that polydrug use and drug dependence are shared across various substances. We hypothesize that an animal bred for its alcohol preference would develop opioid dependence and further that this would be associated with the overt cortical abnormalities clinically described for opioid addicts. We show that Wistar-derived outbred UChB rats selected for their high alcohol preference additionally develop: (i) a preference for oral ingestion of morphine over water, resulting in morphine intake of 15 mg/kg/day; (ii) marked opioid dependence, as evidenced by the generation of strong withdrawal signs upon naloxone administration; (iii) prefrontal cortex alterations known to be associated with the loss of control over drug intake, namely, demyelination, axonal degeneration, and a reduction in glutamate transporter GLT-1 levels; and (iv) glial striatal neuroinflammation and brain oxidative stress, as previously reported for chronic alcohol and chronic nicotine use. These findings underline the relevance of polydrug animal models and their potential in the study of the wide spectrum of brain alterations induced by chronic morphine intake. This study should be valuable for future evaluations of therapeutic approaches for this devastating condition.
Asunto(s)
Dependencia de Morfina , Trastornos Relacionados con Sustancias , Humanos , Ratas , Animales , Morfina/efectos adversos , Analgésicos Opioides/farmacología , Ratas Wistar , Naloxona/farmacología , Encéfalo , Trastornos Relacionados con Sustancias/tratamiento farmacológico , Etanol/farmacología , Antagonistas de Narcóticos/farmacologíaRESUMEN
Addiction is a serious public health problem, and the current pharmacotherapy is unable to prevent drug use reinstatement. Studies have focused on physical exercise as a promising coadjuvant treatment. Our research group recently showed beneficial neuroadaptations in the dopaminergic system related to amphetamine-relapse prevention involving physical exercise-induced endogenous opioid system activation (EXE-OS activation). In this context, additional mechanisms were explored to understand the exercise benefits on drug addiction. Male rats previously exposed to amphetamine (AMPH, 4.0 mg/kg) for 8 days were submitted to physical exercise for 5 weeks. EXE-OS activation was blocked by naloxone administration (0.3 mg/kg) 5 min before each physical exercise session. After the exercise protocol, the rats were re-exposed to AMPH for 3 days, and in sequence, euthanasia was performed and the VTA and NAc were dissected. In the VTA, our findings showed increased immunocontent of proBDNF, BDNF, and GDNF and decreased levels of AMPH-induced TrkB; therefore, EXE-OS activation increased all these markers and naloxone administration prevented this exercise-induced effect. In the NAc, the same molecular markers were also increased by AMPH and decreased by EXE-OS activation. In this study, we propose a close relation between EXE-OS activation beneficial influence and a consequent neuroadaptation on neurotrophins and dopaminergic system levels in the mesolimbic brain area, preventing the observed AMPH-relapse behavior. Our outcomes bring additional knowledge concerning addiction neurobiology understanding and show that EXE-OS activation may be a potential adjuvant tool in drug addiction therapy.
Asunto(s)
Trastornos Relacionados con Anfetaminas , Analgésicos Opioides , Ratas , Masculino , Animales , Factores de Crecimiento Nervioso/farmacología , Anfetamina , Encéfalo , Naloxona/farmacología , Núcleo AccumbensRESUMEN
BACKGROUND: Fentanyl is commonly laced with xylazine. People who use this combination report heightened effects, but it also increases death risk. Although no medication has been approved to counteract overdoses produced by fentanyl and xylazine, naloxone is frequently used. This paper studies the preclinical rewarding and lethal effects of fentanyl combined with xylazine and the efficacy of yohimbine or naloxone to prevent death. METHODS: Male Swiss Webster mice were treated with (in mg/kg, i.p.) xylazine (0.3, 1, 3, or 5.6), fentanyl (0.01, 0.3, or 0.1), or 1 xylazine plus 0.01 (non-effective) or 0.1 (effective) fentanyl doses during the conditioned-place preference (CPP) test. In addition, independent groups received (in mg/kg, i.p.): xylazine (31.6, 60, 74.2, or 100), fentanyl (3.1 or 10), or both substances at two doses: 31.6 xylazine + 3.1 fentanyl, or 60 xylazine + 10 fentanyl to analyze lethal effects. We determined whether yohimbine or naloxone (each medication tested at 10 or 30mg/kg) could prevent the lethality produced by fentanyl/xylazine combinations. Female mice were also tested in key experiments. RESULTS: Xylazine neither induced CPP nor altered fentanyl's rewarding effects. In contrast, lethality was potentiated when fentanyl was combined with xylazine. Naloxone, but not yohimbine, effectively prevented the lethality of the fentanyl/xylazine combinations. CONCLUSIONS: At the doses tested, xylazine does not increase the rewarding effect of fentanyl on the CPP in male mice but potentiates the risk of fatal overdose in male and female mice. A high naloxone dose prevents death induced by coadministration of fentanyl and xylazine in both sexes.
Asunto(s)
Sobredosis de Droga , Xilazina , Humanos , Masculino , Femenino , Ratones , Animales , Xilazina/farmacología , Fentanilo/farmacología , Yohimbina/farmacología , Naloxona/farmacología , Analgésicos OpioidesRESUMEN
The misuse of and addiction to opioids are serious public health problems in some countries, such as the USA. Drug addiction is a chronic and relapsing medical condition that involves motivational and memory-related processes due to the strong associations between drugs and consuming-related stimuli. These stimuli usually trigger continuous and compulsive use and are associated with relapses after periods of withdrawal. Several factors contribute to relapse, including withdrawal-induced mood changes. Therefore, drugs attenuating withdrawal-induced affective alterations could be useful alternative treatments for relapse prevention. Cannabidiol (CBD), a non-psychotomimetic component from the Cannabis sativa plant, has anti-anxiety and anti-stress properties and has been investigated as an alternative for the treatment of several mental disorders, including drug addiction. Here, we evaluated if CBD administered 30 min prior to test for a conditioned place aversion (CPA) would attenuate the aversion induced by morphine withdrawal precipitated by the opioid receptor antagonist naloxone in male C57BL/6 mice. We also investigated if this effect involves the activation of 5-HT1A receptors, a mechanism previously associated with CBD anti-aversive effects. As expected, morphine-treated mice spent less time exploring the compartment paired with the naloxone-induced withdrawal, indicating a CPA induced by naloxone-precipitated morphine withdrawal. This effect was not observed in animals treated with CBD, at 30 and 60 mg/kg, prior to the CPA test, indicating that CBD attenuated the expression of CPA induced by naloxone-precipitated morphine withdrawal. Pretreatment with the 5-HT1A receptor antagonist WAY100635 (0.3 mg/kg) blocked CBD effects. Our findings suggest that CBD may reduce the expression of a previously established conditioned aversion induced by morphine withdrawal by a mechanism involving the activation of 5-HT1A receptors. Thus, CBD may be a therapeutic alternative for preventing relapse to opioid addiction by decreasing withdrawal-induced negative affective changes.
Asunto(s)
Cannabidiol , Dependencia de Morfina , Síndrome de Abstinencia a Sustancias , Ratones , Animales , Naloxona/farmacología , Morfina/efectos adversos , Cannabidiol/farmacología , Receptor de Serotonina 5-HT1A , Reacción de Prevención , Síndrome de Abstinencia a Sustancias/metabolismo , Ratones Endogámicos C57BL , Antagonistas de Narcóticos/farmacología , Dependencia de Morfina/tratamiento farmacológico , Dependencia de Morfina/metabolismoRESUMEN
Opioid drugs have analgesic properties used to treat chronic and post-surgical pain due to descending pain modulation. The use of opioids is often associated with adverse effects or clinical issues. This study aimed to evaluate the toxicity of opioids by exposing the neuroblastoma cell line (SH-SY5Y) to 0, 1, 10, and 100 µM oxycodone and naloxone for 24 h. Analyses were carried out to evaluate cell cytotoxicity, identification of cell death, DNA damage, superoxide dismutase (SOD), glutathione S-transferase (GST), and acetylcholinesterase (AChE) activities, in addition to molecular docking. Oxycodone and naloxone exposure did not alter the SH-SY5Y cell viability. The exposure to 100 µM oxycodone and naloxone significantly increased the cells' DNA damage score compared to the control group. Naloxone exposure significantly inhibited AChE, GST, and SOD activities, while oxycodone did not alter these enzymes' activities. Molecular docking showed that naloxone and oxycodone interact with different amino acids in the studied enzymes, which may explain the differences in enzymatic inhibition. Naloxone altered the antioxidant defenses of SH-SY5Y cells, which may have caused DNA damage 24 h after the exposure. On the other hand, more studies are necessary to explain how oxycodone causes DNA damage.
Asunto(s)
Neuroblastoma , Oxicodona , Humanos , Oxicodona/efectos adversos , Naloxona/farmacología , Acetilcolinesterasa , Simulación del Acoplamiento Molecular , Estreñimiento/tratamiento farmacológico , Neuroblastoma/tratamiento farmacológico , Analgésicos Opioides/efectos adversos , Dolor Postoperatorio/tratamiento farmacológico , Línea Celular , Superóxido Dismutasa , Preparaciones de Acción Retardada/uso terapéutico , Combinación de MedicamentosRESUMEN
Pamabrom is a diuretic that is effective in treating premenstrual syndrome and primary dysmenorrhea. The aim of this study was to examine the effect of metformin and modulators of the opioid receptor-nitric oxide (NO)-cyclic guanosine monophosphate (cGMP)-K+ channel pathway on the local antinociception induced by pamabrom. The rat paw 1% formalin test was used to assess the effects. Rats were treated with local administration of pamabrom (200-800 µg/paw) or indomethacin (200-800 µg/paw). The antinociception of pamabrom or indomethacin was evaluated with and without the local pretreatment of the blockers. Local administration of pamabrom and indomethacin produced dose-dependent antinociception during the second phase of the test. Local pretreatment of the paws with naloxone (50 µg/paw), l-nitro-arginine methyl ester (10-100 µg/paw), or 1H-(1,2,4)-oxadiazolo[4,2-a]quinoxalin-1-one (10-100 µg/paw) reverted the antinociception induced by local pamabrom, but not of indomethacin. Similarly, the K+ channel blockers glibenclamide, glipizide, 4-aminopyridine, tetraethylammonium, charybdotoxin, or apamin reverted the pamabrom-induced antinociception, but not of indomethacin. Metformin significantly blocked the antinociception of pamabrom and indomethacin. Our data suggest that pamabrom could activate the opioid receptor-NO-cGMP-K+ channel pathway to produce its peripheral antinociception in the formalin test. Likewise, a biguanide-dependent mechanism could be activated by pamabrom and indomethacin to generate antinociception.
Asunto(s)
Metformina , Naloxona , Femenino , Ratas , Animales , Naloxona/farmacología , GMP Cíclico/metabolismo , Ratas Wistar , Óxido Nítrico/metabolismo , Diuréticos , Metformina/farmacología , Indometacina , Receptores Opioides , Analgésicos/farmacología , Bloqueadores de los Canales de Potasio/farmacologíaRESUMEN
The lateral hypothalamus (LH) sends neural pathways to structures involved on predatorrelated defensive behaviours, escape and antinociception. The aim of this study was to investigate the role played by µ-opioid receptors located on LH neurons in defensive behaviour and unconditioned fearinduced antinociception elicited by electric stimulation of LH. To achieve the goals, the µ1-opioid receptor selective antagonist naloxonazine was administered at different concentrations in the LH, and the defensive behaviour and fearinduced antinociception elicited by electrical stimulation of LH were evaluated. The electrical stimulation of LH caused escape behaviour followed by defensive antinociception. Microinjections of naloxonazine in a concentration of 5.0 µg/0.2 µL in the LH decreased the aversive stimulusinduced escape behaviour thresholds, but diminished defensive antinociception. These findings suggest that µ-opioid receptors of LH can be critical to panic attackrelated symptoms and facilitate the unconditioned fearinduced antinociception produced by LH neurons activation.
Asunto(s)
Conducta Animal , Área Hipotalámica Lateral , Trastorno de Pánico , Receptores Opioides mu , Animales , Conducta Animal/efectos de los fármacos , Conducta Animal/fisiología , Bicuculina/farmacología , Miedo/fisiología , Área Hipotalámica Lateral/efectos de los fármacos , Área Hipotalámica Lateral/metabolismo , Naloxona/análogos & derivados , Naloxona/farmacología , Antagonistas de Narcóticos/farmacología , Nocicepción , Pánico/fisiología , Trastorno de Pánico/metabolismo , Trastorno de Pánico/psicología , Ratas , Ratas Wistar , Receptores Opioides mu/antagonistas & inhibidores , Receptores Opioides mu/metabolismoRESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Eugenia uniflora (Myrtaceae) is a species native to Brazil and has a traditional use in the treatment of inflammation. AIM OF THE STUDY: To evaluate the anti-inflammatory and antinociceptive effects, and the involvement of opioid receptors in the antinociceptive activity of extract and fractions from Eugenia uniflora leaves. MATERIALS AND METHODS: TLC and HPLC were used to characterize the spray-dried extract (SDE) and fractions. In the in vivo assays, Swiss (Mus musculus) mice were used. Carrageenan-induced hind-paw edema and carrageenan-induced peritonitis models were used to determine the anti-inflammatory effect of the extract (50, 100, or 200 mg/kg). Acetic acid-induced writhing, tail-flick, and formalin tests were used to determine the antinociceptive effect of the extract (50, 100, or 200 mg/kg). The aqueous (AqF) and ethyl acetate (EAF) fractions (6.25, 12.5, and 25 mg/kg) were then combined with naloxone to evaluate the involvement of opioid receptors in the antinociceptive activity. RESULTS: In this work, the TLC and HPLC analysis evidenced the enrichment of EAF, which higher concentration of gallic acid (5.29 ± 0.0004 %w/w), and ellagic acid (1.28 ± 0.0002 %w/w) and mainly myricitrin (8.64 ± 0.0002 %w/w). The extract decreased the number of total leukocytes and neutrophils in the peritoneal cavity (p < 0.05), at doses of 100 and 200 mg/kg and showed significant inhibition in the increase of paw edema volume (p < 0.05). The treatment per oral route (doses of 50, 100, and 200 mg/kg) significantly reduced the nociceptive response in acetic acid-induced abdominal writhing (p < 0.05). The effect of the extract on the tail-flick test showed a significant increase in latency time of animals treated at doses of 200 and 100 mg/kg (p < 0.05). The extract and ethyl acetate fraction reduced the nociceptive effect in both phases of formalin at all tested doses. The naloxone reversed the antinociceptive effect of EAF, suggesting that opioid receptors are involved in mediating the antinociceptive activity of EAF of E. uniflora in the formalin test. CONCLUSION: The current study demonstrates the anti-inflammatory and analgesic activities of water: ethanol: propylene glycol spray-dried extract from E. uniflora leaves using in vivo pharmacological models in mice. Our findings suggest that spray-dried extract and ethyl acetate fraction exhibit peripheral and central antinociceptive activity with the involvement of opioid receptors that may be related to the presence of flavonoids, mainly myricitrin.
Asunto(s)
Eugenia , Ácido Acético/uso terapéutico , Analgésicos/farmacología , Analgésicos/uso terapéutico , Animales , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Carragenina , Edema/inducido químicamente , Edema/tratamiento farmacológico , Etanol/uso terapéutico , Ratones , Naloxona/farmacología , Dolor/inducido químicamente , Dolor/tratamiento farmacológico , Extractos Vegetales/farmacología , Extractos Vegetales/uso terapéutico , Glicoles de Propileno/efectos adversos , Receptores Opioides , AguaRESUMEN
Levamisole is a veterinary anthelmintic drug and a common adulterant of misused drugs. This study analyses the lethal, antinociceptive and haematological effects produced by acute or repeated levamisole administration by itself or combined with morphine. Independent groups of male Swiss Webster mice were i.p. injected with 100 mg/kg morphine, 31.6 mg/kg levamisole (lethal doses at 10%, LD10 ) or the same doses combined. Naloxone pretreatment (10 mg/kg, i.p.) prevented morphine-induced death, as did 2.5 mg/kg, i.p. mecamylamine with levamisole. Co-administration of levamisole and morphine (Lvm + Mor) increased lethality from 10% to 80%. This augmented effect was prevented by 30 mg/kg, i.p. naloxone and reduced with 10 mg/kg naloxone plus 2.5 mg/kg, i.p. mecamylamine. In independent groups of mice, 17.7 mg/kg, i.p. levamisole antagonized the acute morphine's antinociceptive effect evaluated in the tail-flick test. Repeated 17.7 mg/kg levamisole administration (2×/day/3 weeks) did not affect tolerance development to morphine (10 mg/kg, 3×/day/1 week). Blood samples obtained from mice repeatedly treated with levamisole showed leukopenia and neutropenia. Morphine also produced neutropenia, increased erythrocyte count and other related parameters (e.g. haemoglobin). Lvm + Mor had similar effects on leukocyte and neutrophil counts to those seen with levamisole only, but no erythrocyte-related alterations were evident. Blood chemistry analysis did not indicate liver damage but suggested some degree of electrolyte balance impairment. In conclusion, Lvm + Mor increased death risk, altered morphine-induced antinociceptive effects and produced haematologic abnormalities. The importance of studying combinations of drugs of abuse lies in the fact that drug users frequently combine drugs, which are commonly adulterated.
Asunto(s)
Morfina , Neutropenia , Analgésicos , Animales , Levamisol/farmacología , Masculino , Mecamilamina , Ratones , Morfina/farmacología , Naloxona/farmacología , Neutropenia/inducido químicamenteRESUMEN
Moderate exercise reduces arterial pressure (AP) and heart rate (HR) in spontaneously hypertensive rats (SHR) and changes neurotransmission in medullary areas involved in cardiovascular regulation. We investigated if regularly swimming exercise (SW) affects the cardiovascular adjustments mediated by opioidergic neuromodulation in the RVLM in SHR and Wistar-Kyoto (WKY) rats. Rats were submitted to 6 wks of SW. The day after the last exercise bout, α-chloralose-anesthetized rats underwent a cannulation of the femoral artery for AP and HR recordings, and Doppler flow probes were placed around the lower abdominal aorta and superior mesenteric artery. Bilateral injection of endomorphin-2 (EM-2, 0.4 mmol/L, 60 nL) into the RVLM increased MAP in SW-SHR (20 ± 4 mmHg, N = 6), which was lower than in sedentary (SED)-SHR (35 ± 4 mmHg, N = 6). The increase in MAP in SW-SHR induced by EM-2 into the RVLM was similar in SED- and SW-WKY. Naloxone (0.5 mmol/L, 60 nL) injected into the RVLM evoked an enhanced hypotension in SW-SHR (-66 ± 8 mmHg, N = 6) compared to SED-SHR (-25 ± 3 mmHg, N = 6), which was similar in SED- and SW-WKY. No significant changes were observed in HR after EM-2 or naloxone injections into the RVLM. Changes in hindquarter and mesenteric conductances evoked by EM-2 or naloxone injections into the RVLM in SW- or SED-SHR were not different. Mu Opioid Receptor expression by Western blotting was reduced in SW-SHR than in SED-SHR and SW-WKY. Therefore, regularly SW alters the opioidergic neuromodulation in the RVLM in SHR and modifies the mu opioid receptor expression in this medullary area.
Asunto(s)
Analgésicos Opioides/farmacología , Hipertensión/metabolismo , Bulbo Raquídeo/metabolismo , Neuronas/efectos de los fármacos , Condicionamiento Físico Animal , Receptores Opioides mu/metabolismo , Animales , Presión Arterial/efectos de los fármacos , Presión Arterial/fisiología , Frecuencia Cardíaca/efectos de los fármacos , Frecuencia Cardíaca/fisiología , Bulbo Raquídeo/efectos de los fármacos , Naloxona/farmacología , Antagonistas de Narcóticos/farmacología , Neuronas/metabolismo , Oligopéptidos/farmacología , Ratas , Ratas Endogámicas SHR , Ratas Endogámicas WKY , NataciónRESUMEN
The participation of the peripheral opioid and cannabinoid endogenous systems in modulating muscle pain and inflammation has not been fully explored. Thus, the aim of this study was to investigate the involvement of these endogenous systems during muscular-tissue hyperalgesia induced by inflammation. Hyperalgesia was induced by carrageenan injection into the tibialis anterior muscles of male Wistar rats. We padronized an available Randal-Sellito test adaptation to evaluate nociceptive behavior elicited by mechanical insult in muscles. Western blot analysis was performed to evaluate the expression levels of opioid and cannabinoid receptors in the dorsal root ganglia. The non-selective opioid peptide receptor antagonist (naloxone) and the selective mu opioid receptor MOP (clocinnamox) and kappa opioid receptor KOP (nor-binaltorphimine) antagonists were able to intensify carrageenan-induced muscular hyperalgesia. On the other hand, the selective delta opioid receptor (DOP) antagonist (naltrindole) did not present any effect on nociceptive behavior. Moreover, the selective inhibitor of aminopeptidases (Bestatin) provoked considerable dose-dependent analgesia when intramuscularly injected into the hyperalgesic muscle. The CB1 receptor antagonist (AM251), but not the CB2 receptor antagonist (AM630), intensified muscle hyperalgesia. All irreversible inhibitors of anandamide hydrolase (MAFP), the inhibitor for monoacylglycerol lipase (JZL184) and the anandamide reuptake inhibitor (VDM11) decreased carrageenan-induced hyperalgesia in muscular tissue. Lastly, MOP, KOP and CB1 expression levels in DRG were baseline even after muscular injection with carrageenan. The endogenous opioid and cannabinoid systems participate in peripheral muscle pain control through the activation of MOP, KOP and CB1 receptors.
Asunto(s)
Mialgia/tratamiento farmacológico , Receptores de Cannabinoides/fisiología , Receptores Opioides/fisiología , Animales , Ácidos Araquidónicos/antagonistas & inhibidores , Carragenina , Cinamatos/farmacología , Endocannabinoides/antagonistas & inhibidores , Hiperalgesia/inducido químicamente , Hiperalgesia/tratamiento farmacológico , Hiperalgesia/psicología , Masculino , Monoacilglicerol Lipasas/antagonistas & inhibidores , Derivados de la Morfina/farmacología , Mialgia/inducido químicamente , Mialgia/psicología , Naloxona/farmacología , Naltrexona/análogos & derivados , Naltrexona/farmacología , Dimensión del Dolor/efectos de los fármacos , Alcamidas Poliinsaturadas/antagonistas & inhibidores , Ratas , Ratas Wistar , Receptores de Cannabinoides/efectos de los fármacos , Receptores Opioides/efectos de los fármacos , Receptores Opioides delta/efectos de los fármacos , Receptores Opioides kappa/efectos de los fármacos , Receptores Opioides mu/efectos de los fármacosRESUMEN
Spirulina platensis is a "super-food" and has attracted researchers' attention due to its anti-inflammatory, antioxidant, and analgesic properties. Herein, we investigated the antinociceptive effects of Spirulina in different rodent behavior models of inflammatory pain. Male Swiss mice were treated with Spirulina (3-300 mg/kg, p.o.), indomethacin (10 mg/kg, p.o.), or vehicle (0.9% NaCl 10 mL/kg). Behavioral tests were performed with administration of acetic acid (0.6%, i.p.), formalin 2.7% (formaldehyde 1%, i.pl.), menthol (1.2 µmol/paw, i.pl.), cinnamaldehyde (10 nmol/paw, i.pl.), capsaicin (1.6 µg/paw, i.pl.), glutamate (20 µmol/paw, i.pl.), or naloxone (1 mg/kg, i.p.). The animals were also exposed to the rotarod and open field test to determine possible effects of Spirulina on locomotion and motor coordination. The quantitative phytochemical assays exhibited that Spirulina contains significant concentrations of total phenols and flavonoid contents, as well as it showed a powerful antioxidant effect with the highest scavenging activity. Oral administration of Spirulina completely inhibited the abdominal contortions induced by acetic acid (ED50 = 20.51 mg/kg). Spirulina treatment showed significant inhibition of formalin-induced nociceptive behavior during the inflammatory phase, and the opioid-selective antagonist markedly blocked this effect. Furthermore, our data indicate that the mechanisms underlying Spirulina analgesia appear to be related to its ability to modulate TRMP8 and TRPA1, but not by TRPV1 or glutamatergic system. Spirulina represents an orally active and safe natural analgesic that exhibits great therapeutic potential for managing inflammatory pain disorders.
Asunto(s)
Analgésicos/farmacología , Antagonistas de Narcóticos/farmacología , Dolor Nociceptivo/tratamiento farmacológico , Extractos Vegetales/farmacología , Spirulina/química , Canal Catiónico TRPA1/metabolismo , Canales Catiónicos TRPM/metabolismo , Analgésicos/uso terapéutico , Animales , Capsaicina/farmacología , Masculino , Ratones , Naloxona/farmacología , Nocicepción/efectos de los fármacos , Extractos Vegetales/uso terapéuticoRESUMEN
Pharmacological agents directed to either opioid receptors or peroxisome proliferator-activated receptor gamma (PPARγ) at peripheral tissues reduce behavioral signs of persistent pain. Both receptors are expressed in muscle tissue, but the contribution of PPARγ activation to muscle pain and its modulation by opioid receptors remains unknown. To address this question, we first tested whether the endogenous PPARγ ligand 15d-PGJ2 would decrease mechanical hyperalgesia induced by carrageenan administration into the gastrocnemius muscle of rats. Next, we used receptor antagonists to determine whether the antihyperalgesic effect of 15-deoxyΔ-12,14-prostaglandin J2 (15d-PGJ2) was PPARγ- or opioid receptor-dependent. Three hours after carrageenan, muscle hyperalgesia was quantified with the Randall-Selitto test. 15d-PGJ2 prevented carrageenan-induced muscle hyperalgesia in a dose-dependent manner. The antihyperalgesic effect of 15d-PGJ2 was dose-dependently inhibited by either the PPARγ antagonist, 2-chloro-5-nitro-N-phenylbenzamide, or by the opioid receptor antagonist, naloxone. We conclude that 15d-PGJ2 targets PPARγ and opioid receptors to prevent muscle hyperalgesia. We suggest that local PPARγ receptors are important pharmacological targets for inflammatory muscle pain.
Asunto(s)
Hiperalgesia/metabolismo , Factores Inmunológicos/farmacología , Músculo Esquelético/efectos de los fármacos , Mialgia/metabolismo , PPAR gamma/efectos de los fármacos , Prostaglandina D2/análogos & derivados , Anilidas/farmacología , Animales , Conducta Animal/efectos de los fármacos , Carragenina/toxicidad , Hiperalgesia/inducido químicamente , Músculo Esquelético/metabolismo , Mialgia/inducido químicamente , Naloxona/farmacología , Antagonistas de Narcóticos/farmacología , PPAR gamma/antagonistas & inhibidores , Prostaglandina D2/farmacología , RatasRESUMEN
The pro-resolving mechanism is a recently described endogenous process that controls inflammation. The present study evaluated components of this mechanism, including annexin 1 (ANXA1) and the formyl peptide receptor 2/ALX (FPR2/ALX) receptor, in the antihyperalgesic effect induced by electroacupuncture (EA) in an animal model of persistent peripheral inflammation. Male Swiss mice underwent intraplantar (i.pl.) injection with complete Freund's adjuvant (CFA). Mechanical hyperalgesia was assessed with von Frey monofilaments. Animals were treated with EA (2-10 Hz, ST36-SP6) or subcutaneous BML-111 injection (FPR2/ALX agonist) for 5 consecutive days. In a separate set of experiments, on the first and fifth days after CFA injection, animals received i.pl. WRW4 (FPR2/ALX antagonist) or naloxone (non-selective opioid receptor antagonist) before EA or BML-111 injection. Paw protein levels of FPR2/ALX and ANXA1 were evaluated on the second day after CFA injection by western blotting technique. EA and BML-111 reduced mechanical hyperalgesia. I.pl. naloxone or WRW4 prevented the antihyperalgesic effect induced by either EA or BML-111. EA increased ANXA1 but did not alter FPR2/ALX receptor levels in the paw. Furthermore, i.pl. pretreatment with WRW4 prevented the increase of ANXA1 levels induced by EA. This work demonstrates that the EA antihyperalgesic effect on inflammatory pain involves the ANXA1/FPR2/ALX pro-resolution pathway. This effect appears to be triggered by the activation of FPR2/ALX receptors and crosstalk communication with the opioid system.
Asunto(s)
Anexina A1/metabolismo , Electroacupuntura/métodos , Hiperalgesia/terapia , Dolor Nociceptivo/terapia , Receptores de Formil Péptido/metabolismo , Receptores Opioides/metabolismo , Animales , Adyuvante de Freund/toxicidad , Ácidos Heptanoicos/farmacología , Hiperalgesia/etiología , Hiperalgesia/metabolismo , Masculino , Ratones , Naloxona/farmacología , Antagonistas de Narcóticos/farmacología , Nocicepción/efectos de los fármacos , Dolor Nociceptivo/etiología , Dolor Nociceptivo/metabolismo , Receptores de Formil Péptido/antagonistas & inhibidores , Receptores Opioides/uso terapéuticoRESUMEN
Currently, photobiomodulation therapy (PBMT) is gaining space in the scientific and clinical environment. To help elucidate the importance of irradiance, this study evaluated the effect of two different PBMT irradiances (3.5 and 90 mW/cm2), given a fixed wavelength of 630 nm and a dose of 2 J/cm2, on mechanical hyperalgesia following Complete Freund's Adjuvant (CFA) intraplantar (i.pl.) injection in mice. Additionally, we investigated the role of peripheral opioid and endothelin-B receptors (ETB-R), as well as sex differences in treatment outcome. Different groups of male or female mice were evaluated 6 and 96 h after CFA. Mechanical hyperalgesia was evaluated 30 min after treatments. Naloxone or Bq-788 administration, fifteen minutes before PBMT or Sarafotoxin S6c, helped determine the involvement of peripheral opioid and ETB-Rs on PBMT. Lastly, ETB-Rs skin immunocontent in both sexes was quantified after PBMT consecutive daily treatments. PBMT at an irradiance of 90 mW/cm2, was more effective than 3.5 mW/cm2. Bq-788 and naloxone administration prevented the effects of PBMT and SRTX S6c; however, PBMT did not influence peripheral ETB-Rs immunocontent. The results suggest that irradiance influences PMBT effect; and that activation of ETB-R play a role in peripheral PBMT opioid induced analgesia. Lastly, PMBT effects do not appear to be sex-dependent.
Asunto(s)
Analgésicos Opioides/efectos de la radiación , Hiperalgesia/radioterapia , Terapia por Luz de Baja Intensidad/métodos , Receptor de Endotelina B/efectos de la radiación , Animales , Relación Dosis-Respuesta en la Radiación , Femenino , Masculino , Ratones , Naloxona/farmacología , Oligopéptidos/farmacología , Piperidinas/farmacología , Exposición a la Radiación , Factores Sexuales , Factores de Tiempo , Venenos de Víboras/metabolismoRESUMEN
Drugs used to treat pain are associated with adverse effects, increasing the search for new drugs as an alternative treatment for pain. Therefore, we evaluated the antinociceptive behavior and possible neuromodulation mechanisms of triterpene 3ß, 6ß, 16ß-trihydroxylup-20(29)-ene (CLF-1) isolated from Combretum leprosum leaves in zebrafish. Zebrafish (n = 6/group) were pretreated with CLF-1 (0.1 or 0.3 or 1.0 mg/mL; i.p.) and underwent nociception behavior tests. The antinociceptive effect of CFL-1 was tested for modulation by opioid (naloxone), nitrergic (L-NAME), nitric oxide and guanylate cyclase synthesis inhibitor (methylene blue), NMDA (Ketamine), TRPV1 (ruthenium red), TRPA1 (camphor), or ASIC (amiloride) antagonists. The corneal antinociceptive effect of CFL-1 was tested for modulation by TRPV1 (capsazepine). The effect of CFL-1 on zebrafish locomotor behavior was evaluated with the open field test. The acute toxicity study was conducted. CLF-1 reduced nociceptive behavior and corneal in zebrafish without mortalities and without altering the animals' locomotion. Thus, CFL-1 presenting pharmacological potential for the treatment of acute pain and corneal pain, and this effect is modulated by the opioids, nitrergic system, NMDA receptors and TRP and ASIC channels.
Asunto(s)
Analgésicos/farmacología , Combretum/química , Locomoción/efectos de los fármacos , Nocicepción/efectos de los fármacos , Dolor/prevención & control , Triterpenos/farmacología , Canales Iónicos Sensibles al Ácido/metabolismo , Amilorida/farmacología , Analgésicos/aislamiento & purificación , Animales , Alcanfor/farmacología , Capsaicina/análogos & derivados , Capsaicina/farmacología , Relación Dosis-Respuesta a Droga , Femenino , Ketamina/farmacología , Locomoción/fisiología , Masculino , Azul de Metileno/farmacología , NG-Nitroarginina Metil Éster/farmacología , Naloxona/farmacología , Nocicepción/fisiología , Dolor/metabolismo , Dolor/fisiopatología , Dimensión del Dolor , Extractos Vegetales/química , Hojas de la Planta/química , Receptores de N-Metil-D-Aspartato/metabolismo , Rojo de Rutenio/farmacología , Canales Catiónicos TRPV/metabolismo , Triterpenos/aislamiento & purificación , Pez Cebra , Proteínas de Pez Cebra/metabolismoRESUMEN
Psychostimulant drugs addiction is a chronic public health problem and individuals remain susceptible to relapses increasing public expenses even after withdrawal and treatment. Our research group has focused on finding new therapies to be employed in drug addiction treatment, suggesting the physical exercise as a promising tool. This way, it is necessary to know the mechanisms involved in the beneficial influences of physical exercise observing the pathway that could be explored in drug addiction treatment. Male Wistar rats were conditioned with amphetamine (AMPH) following the conditioned place preference (CPP) protocol and subsequently submitted to swimming for 5 weeks (1 h per day, 5 days per week). Half of the animals were injected with Naloxone (0.3 mg/mL/kg body weight, i.p.) 5 min prior each physical exercise day. After AMPH-CPP re-exposure, our outcomes showed that physical exercise, in addition to minimizing the relapse behavior in the CPP, it increased D1R, D2R and DAT in the Ventral Tegmental Area (VTA), but not in the Nucleus accumbens (NAc). Interestingly, while naloxone inhibited the partial beneficial influence of the exercise on drug-relapse behavior, exercise-induced changes in the dopaminergic system were not observed in the group administered with naloxone as well. Based on these evidences, besides reinforcing the beneficial influence of the physical exercise on AMPH-induced drug addiction, we propose the involvement of endogenous opioid system activation, not as a single one, but as a possible mechanism of action resulting from the physical activity practice, thus characterizing an important therapeutic approach, which may contribute to drug withdrawal consequently preventing relapse.
Asunto(s)
Trastornos Relacionados con Anfetaminas/terapia , Anfetamina/farmacología , Estimulantes del Sistema Nervioso Central/farmacología , Condicionamiento Físico Animal/métodos , Animales , Condicionamiento Clásico/efectos de los fármacos , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/metabolismo , Locomoción/efectos de los fármacos , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Naloxona/farmacología , Antagonistas de Narcóticos/farmacología , Núcleo Accumbens/metabolismo , Ratas , Ratas Wistar , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D2/metabolismo , Transducción de Señal/efectos de los fármacos , Natación , Área Tegmental Ventral/metabolismoRESUMEN
Cyclo-Gly-Pro (CGP) attenuates nociception, however its effects on salivary glands remain unclear. In this study, we investigated the acute effects of CGP on salivary flow and composition, and on the submandibular gland composition, compared with morphine. Besides, we characterized the effects of naloxone (a non-selective opioid receptor antagonist) on CGP- and morphine-induced salivary and glandular alterations in mice. After that, in silico analyses were performed to predict the interaction between CGP and opioid receptors. Morphine and CGP significantly reduced salivary flow and total protein concentration of saliva and naloxone restored them to the physiological levels. Morphine and CGP also reduced several infrared vibrational modes (Amide I, 1687-1594cm-1; Amide II, 1594-1494cm-1; CH2/CH3, 1488-1433cm-1; C = O, 1432-1365cm-1; PO2 asymmetric, 1290-1185cm-1; PO2 symmetric, 1135-999cm-1) and naloxone reverted these alterations. The in silico docking analysis demonstrated the interaction of polar contacts between the CGP and opioid receptor Cys219 residue. Altogether, we showed that salivary hypofunction and glandular changes elicited by CGP may occur through opioid receptor suggesting that the blockage of opioid receptors in superior cervical and submandibular ganglions may be a possible strategy to restore salivary secretion while maintaining antinociceptive action due its effects on the central nervous system.