RESUMEN
BACKGROUND: Recently, we demonstrated that nicorandil inhibits mechanical allodynia induced by paclitaxel. In the present study, we evaluated the effect induced by nicorandil in a model of neuropathic pain induced by chronic constriction injury (CCI) in mice. We also investigated putative mechanisms underlying such an effect. METHODS: CCI was induced by three ligatures of the left sciatic nerve. Mechanical allodynia was evaluated by measuring the paw withdrawal threshold with an electronic von Frey apparatus. Concentrations of cytokines and myeloperoxidase activity were determined in the paw tissue, sciatic nerve, and dorsal root ganglia (DRG). RESULTS: Oral administration of two doses of nicorandil (150 mg/kg po), but not equimolar doses of nicotinamide or nicotinic acid, attenuated mechanical allodynia induced by CCI. Nicorandil activity was reduced by previous administration of glibenclamide (40 mg/kg) or naltrexone (5 mg/kg or 10 mg/kg). Two doses of nicorandil (150 mg/kg, po) reduced tumor necrosis factor-α, interleukin-1ß and interleukin-6, but not CXCL-1, concentrations in the paw tissue of CCI mice. Two doses of nicorandil (150 mg/kg, po) reduced concentrations of all these mediators in the sciatic nerve and DRG. Two doses of nicorandil (150 mg/kg, po) also reduced the myeloperoxidase activity in the paw tissue, sciatic nerve, and DRG. CONCLUSIONS: Nicorandil exhibits antiallodynic activity in a model of neuropathic pain induced by CCI. Inhibition of cytokines production and reduction of neutrophils recruitment in paw tissue, sciatic nerve, and DRG as well as activation of ATP-dependent potassium channels and opioidergic pathways, underlie nicorandil antiallodynic activity.
Asunto(s)
Citocinas , Modelos Animales de Enfermedad , Ganglios Espinales , Hiperalgesia , Canales KATP , Neuralgia , Nicorandil , Nervio Ciático , Animales , Nicorandil/farmacología , Neuralgia/tratamiento farmacológico , Neuralgia/metabolismo , Ganglios Espinales/metabolismo , Ganglios Espinales/efectos de los fármacos , Ratones , Nervio Ciático/efectos de los fármacos , Nervio Ciático/metabolismo , Masculino , Citocinas/metabolismo , Canales KATP/metabolismo , Hiperalgesia/tratamiento farmacológico , Hiperalgesia/metabolismo , Gliburida/farmacología , Naltrexona/farmacología , Naltrexona/análogos & derivados , Peroxidasa/metabolismo , Infiltración Neutrófila/efectos de los fármacos , Analgésicos/farmacologíaRESUMEN
Anethole is a terpenoid with antioxidant, anti-inflammatory, and neuronal blockade effects, and the present work was undertaken to study the neuroprotective activity of anethole against diabetes mellitus (DM)-induced neuropathy. Streptozotocin-induced DM rats were used to investigate the effects of anethole treatment on morphological, electrophysiological, and biochemical alterations of the sciatic nerve (SN). Anethole partially prevented the mechanical hyposensitivity caused by DM and fully prevented the DM-induced decrease in the cross-sectional area of the SN. In relation to electrophysiological properties of SN fibers, DM reduced the frequency of occurrence of the 3rd component of the compound action potential (CAP) by 15%. It also significantly reduced the conduction velocity of the 1st and 2nd CAP components from 104.6 ± 3.47 and 39.8 ± 1.02 to 89.9 ± 3.03 and 35.4 ± 1.56 m/s, respectively, and increased the duration of the 2nd CAP component from 0.66 ± 0.04 to 0.82 ± 0.09 ms. DM also increases oxidative stress in the SN, altering values related to thiol, TBARS, SOD, and CAT activities. Anethole was capable of fully preventing all these DM electrophysiological and biochemical alterations in the nerve. Thus, the magnitude of the DM-induced neural effects seen in this work, and the prevention afforded by anethole treatment, place this compound in a very favorable position as a potential therapeutic agent for treating diabetic peripheral neuropathy.
Asunto(s)
Derivados de Alilbenceno , Anisoles , Diabetes Mellitus Experimental , Estrés Oxidativo , Nervio Ciático , Animales , Derivados de Alilbenceno/farmacología , Nervio Ciático/efectos de los fármacos , Diabetes Mellitus Experimental/tratamiento farmacológico , Ratas , Anisoles/farmacología , Anisoles/uso terapéutico , Masculino , Estrés Oxidativo/efectos de los fármacos , Ratas Wistar , Neuropatías Diabéticas/tratamiento farmacológico , Neuropatías Diabéticas/prevención & control , Neuropatías Diabéticas/metabolismo , Potenciales de Acción/efectos de los fármacos , Antioxidantes/farmacología , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéuticoRESUMEN
Neuropathic pain is a high-intensity pain that can be caused by compression, transection, injury, nerve infiltration and drug treatment of cancer. Furthermore, drug therapy has low clinical efficacy, many adverse effects and remission of painful symptoms. In this way, natural products derived from plants constitute a promising therapeutic alternative. Therefore, the aim of this study was to evaluate the antihyperalgesic effect of γ-terpinene (γ-TPN) e γ-terpinene in ß-cyclodextrin inclusion complexes (TPN/CD) on neuropathic pain induced by tumor cells. Complexation extended the effect time for another 5 h and daily treatment for six days with γ-TPN (50 mg/kg, p.o.) and γ-TPN/ß-CD (50 mg/kg, p.o.) significantly reduced (p < 0.001) the mechanical hyperalgesia induced by the administration of 2x106 sarcoma cells 180 in the around the sciatic nerve. In addition, the Grip and Rota-rod techniques demonstrated that there was no interference on the muscle strength and motor coordination of the animals, suggesting that the compound under study does not have central nervous system depressant effects at the doses used. Molecular docking studies demonstrate favorable binding energies between γ-TPN and ß-CD, and alpha-2 adrenergic, glutamatergic, opioid and cholinergic receptors. Thus, this study demonstrates the potential of terpinene complexation in controlling neuropathic pain induced by tumor cells.
Asunto(s)
Monoterpenos Ciclohexánicos , Hiperalgesia , Monoterpenos , Neuralgia , beta-Ciclodextrinas , Animales , beta-Ciclodextrinas/química , beta-Ciclodextrinas/administración & dosificación , Neuralgia/tratamiento farmacológico , Hiperalgesia/tratamiento farmacológico , Masculino , Monoterpenos/farmacología , Monoterpenos/química , Monoterpenos/administración & dosificación , Ratones , Analgésicos/farmacología , Analgésicos/química , Analgésicos/administración & dosificación , Modelos Animales de Enfermedad , Nervio Ciático/efectos de los fármacos , Nervio Ciático/lesiones , Línea Celular Tumoral , Simulación del Acoplamiento Molecular , Sarcoma 180/tratamiento farmacológico , Sarcoma 180/patologíaRESUMEN
OBJECTIVES: This work investigated the acute antinociceptive effect of a synthetic chalcone, 4-dimethylamino chalcone (DMAC), as well as its effects on vincristine-induced peripheral neuropathy (VIPN) in mice. METHODS: The inhibitory activity of myeloperoxidase was assessed by measuring HOCl formation. Formalin and hot plate tests were used to study the acute antinociceptive effect of DMAC. VIPN was induced through the administration of vincristine sulphate (0.1 mg/kg, i.p., 14 days). Then, DMSO, DMAC (10 or 30 mg/kg; i.p.), or pregabalin (10 mg/kg, i.p.) were administered for 14 consecutive days. Thermal hyperalgesia and mechanical allodynia were evaluated before and after VIPN induction and on days 1, 3, 7, and 14 of treatment. Neurodegeneration and neuroinflammation were assessed through immunohistochemistry for NF200, iNOS, and arginase-1 within the sciatic nerve. KEY FINDINGS: DMAC inhibited myeloperoxidase activity in vitro and presented an acute antinociceptive effect in both formalin and hot plate tests, with the involvement of muscarinic and opioid receptors. Treatment with 30 mg/kg of DMAC significantly attenuated thermal hyperalgesia and mechanical allodynia and prevented macrophage proinflammatory polarisation in VIPN mice. CONCLUSIONS: Our results show that DMAC, acting through different mechanisms, effectively attenuates VIPN.
Asunto(s)
Analgésicos , Chalconas , Hiperalgesia , Neuralgia , Peroxidasa , Animales , Ratones , Masculino , Analgésicos/farmacología , Neuralgia/tratamiento farmacológico , Hiperalgesia/tratamiento farmacológico , Peroxidasa/metabolismo , Chalconas/farmacología , Vincristina/farmacología , Modelos Animales de Enfermedad , Dolor Agudo/tratamiento farmacológico , Nervio Ciático/efectos de los fármacosRESUMEN
SUMMARY: Microsurgical procedures are the treatment of choice of peripheral nerve injuries, but often fail to reach full functional recovery. Melatonin has neuroprotective actions and might be used as a possible proregenerative pharmacological support. Therefore, the aim of this study was to analyze the time-dependence of the neuroprotective effect of melatonin on the overall fascicular structures of both ends of the transected nerve. Sciatic nerve transection was performed in 34 adult male Wistar rats divided in four groups: two vehicle groups (N=7) treated intraperitoneally for 7 (V7) or 21 (V21) consecutive days with vehicle (5 % ethanol in Ringer solution) and two melatonin groups (N=10) administered intraperitoneally 30 mg/kg of melatonin for 7 (M7) or 21 (M21) consecutive days. At the end of the experiment, proximal stump neuroma and distal stump fibroma were excised and processed for qualitative and quantitative histological analysis. Intrafascicular neural structures were better preserved and the collagen deposition was reduced in the melatonin treated groups than in the vehicle groups. Myelin sheath regeneration observed through its thickness measurement was statistically significantly (p<0,05) more pronounced in the M21 (1,23±0,18 µm) vs. V21 group (0,98±0,13 µm). The mean volume density of the endoneurium was lower in both melatonin treated groups in comparison to the matching vehicle treated groups. Although not statistically different, the endoneural tube diameter was larger in both melatonin groups vs. vehicle groups, and the effect of melatonin was more pronounced after 21 days (24,97 % increase) vs. 7 days of melatonin treatment (18,8 % increase). Melatonin exerts a time-dependent proregenerative effect on nerve fibers in the proximal stump and an anti-scarring effect in both stumps.
Los procedimientos microquirúrgicos son el tratamiento de elección de las lesiones de los nervios periféricos, pero a menudo no logran una recuperación funcional completa. La melatonina tiene acciones neuroprotectoras y podría ser utilizada como un posible apoyo farmacológico proregenerativo. Por lo tanto, el objetivo de este estudio fue analizar la dependencia del tiempo del efecto neuroprotector de la melatonina sobre las estructuras fasciculares generales de ambos extremos del nervio seccionado. La sección del nervio ciático se realizó en 34 ratas Wistar macho adultas divididas en cuatro grupos: dos grupos de vehículo (N=7) tratados por vía intraperitoneal durante 7 (V7) o 21 (V21) días consecutivos con vehículo (5 % de etanol en solución Ringer) y dos grupos grupos de melatonina (N=10) a los que se les administró por vía intraperitoneal 30 mg/kg de melatonina durante 7 (M7) o 21 (M21) días consecutivos. Al final del experimento, se extirparon y procesaron el neuroma del muñón proximal y el fibroma del muñón distal del nervio para un análisis histológico cualitativo y cuantitativo. Las estructuras neurales intrafasciculares se conservaron mejor y el depósito de colágeno se redujo en los grupos tratados con melatonina respecto a los grupos con vehículo. La regeneración de la vaina de mielina observada a través de la medición de su espesor fue estadísticamente significativa (p<0,05) más pronunciada en el grupo M21 (1,23±0,18 µm) vs V21 (0,98±0,13 µm). La densidad de volumen media del endoneuro fue menor en ambos grupos tratados con melatonina en comparación con los grupos tratados con vehículo equivalente. Aunque no fue estadísticamente diferente, el diámetro del tubo endoneural fue mayor en ambos grupos de melatonina frente a los grupos de vehículo, y el efecto de la melatonina fue más pronunciado después de 21 días (aumento del 24,97 %) frente a los 7 días de tratamiento con melatonina (18,8 % de aumento). La melatonina ejerce un efecto proregenerativo dependiente del tiempo sobre las fibras nerviosas del muñón proximal y un efecto anticicatricial en ambos muñones.
Asunto(s)
Animales , Masculino , Ratas , Nervio Ciático/efectos de los fármacos , Melatonina/farmacología , Regeneración Nerviosa/efectos de los fármacos , Nervios Periféricos , Nervio Ciático/fisiología , Factores de Tiempo , Ratas Wistar , Vaina de Mielina/efectos de los fármacos , Regeneración Nerviosa/fisiologíaRESUMEN
This study reports the development of thermosensitive hydrogels for delivering ropivacaine (RVC), a wide clinically used local anesthetic. For this purpose, poloxamer- (PL-) based hydrogels were synthesized for evaluating the influence of polymer concentration, hydrophilic-lipophilic balances, and binary system formation on biopharmaceutical properties and pharmacological performance. Transition temperatures were shifted, and rheological analysis revealed a viscoelastic behavior with enhanced elastic/viscous modulus relationship (G'/G " = 1.8 to 22 times), according to hydrogel composition and RVC incorporation. The RVC release from PL407 and PL407/338 systems followed the Higuchi model (R 2 = 0.923-0.989), indicating the drug diffusion from hydrogels to the medium. RVC-PL hydrogels were potentially biocompatible evoking low cytotoxic effects (in fibroblasts and Schwann cells) and mild/moderate inflammation signs on sciatic nerve nearby histological evaluation. In vivo pharmacological assays demonstrated that PL407 and PL407/338 evoked differential analgesic effects, by prolonging the sensory blockade duration up to ~340 and 250 min., respectively. All those results highlighted PL407 and PL407/338 as promising new strategies for sustaining analgesic effects during the postoperative period.
Asunto(s)
Anestesia Local , Materiales Biocompatibles/química , Hidrogeles/química , Poloxámero/química , Ropivacaína/farmacología , Células 3T3 , Analgesia , Animales , Área Bajo la Curva , Rastreo Diferencial de Calorimetría , Muerte Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Liberación de Fármacos , Elasticidad , Masculino , Ratones , Micelas , Ratas Wistar , Reología , Nervio Ciático/efectos de los fármacos , Sensación/efectos de los fármacos , ViscosidadRESUMEN
A promising alternative to conventional nerve grafting is the use of artificial grafts made from biodegradable and biocompatible materials and support cells. The aim of this study has been to produce a biodegradable nerve conduit and investigate the cytocompatibility with stem cells and its regeneration promoting properties in a rat animal model. A poly (lactic-co-glycolic acid) (PLGA) conduit of aligned nanofibers was produced by the electrospinning method, functionalized with gelatin and seeded either with mouse embryonic stem cells (mESCs) or with human mesenchymal stem cells (SHED). The cell proliferation and viability were analyzed in vitro. The conduits were implanted in a rat model of sciatic nerve lesion by transection. The functional recovery was monitored for 8 weeks using the Sciatic Functional Index (SFI) and histological analyses were used to assess the nerve regeneration. Scaffolds of aligned PLGA fibers with an average diameter of 0.90 ± 0.36 µm and an alignment coefficient of 0.817 ± 0.07 were produced. The treatment with gelatin increased the fiber diameter to 1.05 ± 0.32 µm, reduced the alignment coefficient to 0.655 ± 0.045 and made the scaffold very hydrophilic. The cell viability and Live/dead assay showed that the stem cells remained viable and proliferated after 7 days in culture. Confocal images of phalloidin/DAPI staining showed that the cells adhered and proliferated widely, in fully adaptation with the biomaterial. The SFI values of the group that received the conduit were similar to the values of the control lesioned group. In conclusion, conduits composed of PLGA-gelatin nanofibers were produced and promoted a very good interaction with the stem cells. Although in vitro studies have shown this biomaterial to be a promising biomaterial for the regeneration of nerve tissue, in vivo studies of this graft have not shown significant improvements in nerve regeneration.
Asunto(s)
Gelatina/química , Nanofibras/química , Regeneración Nerviosa/efectos de los fármacos , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/farmacología , Nervio Ciático/efectos de los fármacos , Nervio Ciático/fisiología , Animales , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Humanos , Ratones , Ácido Poliglicólico/química , Ratas , Células de Schwann/citología , Nervio Ciático/citología , Células Madre/citología , Andamios del Tejido/químicaRESUMEN
Duchenne muscular dystrophy (DMD) is a genetic disease linked to the X chromosome induced by mutations in the dystrophin gene. Neuroprotective drugs, such as pregabalin (PGB), can improve motor function through the modulation of excitatory synapses, together with anti-apoptotic and anti-inflammatory effects. The present work studied the effects of PGB in the preservation of dystrophic peripheral nerves, allowing motor improvements in MDX mice. Five weeks old MDX and C57BL/10 mice were treated with PGB (30 mg/kg/day, i.p.) or vehicle, for 28 consecutive days. The mice were sacrificed on the 9th week, the sciatic nerves were dissected out and processed for immunohistochemistry and qRT-PCR, for evaluating the expression of proteins and gene transcripts related to neuronal activity and Schwann cell function. The lumbar spinal cords were also processed for qRT-PCR to evaluate the expression of neurotrophic factors and pro- and anti-inflammatory cytokines. Cranial tibial muscles were dissected out for endplate evaluation with α-bungarotoxin. The recovery of motor function was monitored throughout the treatment, using a spontaneous walking track test (Catwalk system) and a forced locomotion test (Rotarod). The results showed that treatment with PGB reduced the retrograde effects of muscle degeneration/regeneration on the nervous system from the 5th to the 9th week in MDX mice. Thus, PGB induced protein expression in neurons and Schwann cells, protecting myelinated fibers. In turn, better axonal morphology and close-to-normal motor endplates were observed. Indeed, such effects resulted in improved motor coordination of dystrophic animals. We believe that treatment with PGB improved the balance between excitatory and inhibitory inputs to spinal motoneurons, increasing motor control. In addition, PGB enhanced peripheral nerve homeostasis, by positively affecting Schwann cells. In general, the present results indicate that pregabalin is effective in protecting the PNS during the development of DMD, improving motor coordination, indicating possible translation to the clinic.
Asunto(s)
Marcha/efectos de los fármacos , Distrofia Muscular de Duchenne/fisiopatología , Neuroprotección/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Pregabalina/farmacología , Nervio Ciático/efectos de los fármacos , Animales , Modelos Animales de Enfermedad , Masculino , Ratones , Ratones Endogámicos mdx , Distrofia Muscular de Duchenne/tratamiento farmacológico , Fármacos Neuroprotectores/uso terapéutico , Pregabalina/uso terapéutico , Recuperación de la Función/efectos de los fármacos , Nervio Ciático/fisiopatologíaRESUMEN
It has been reported that the Gonadotropin-releasing hormone (GnRH) and its agonist leuprolide acetate (LA) can act as promoters of nerve regeneration. The aim of this study is to evaluate the effect of LA in a complete transection model. Sciatic nerve injury (SNI) was performed using a complete nerve transection and immediately repaired by epineural sutures. Rats were divided into three groups: SHAM, SNI treated with LA (SNI + LA) or saline solution (SNI + SS) for 5 weeks. Sciatic nerve regeneration was evaluated by kinematic gait analyzes, electrophysiological, morphological and biochemical tests. SNI + LA group had a functional recovery in kinematic gait, an increase in ankle angle value and a faster walking speed, compound muscle action potential amplitude, nerve conduction velocity (NCV). Furthermore, the number of myelinated axons and microtubule-associated protein 2 (MAP-2) expression were also higher compared to SS group. In conclusion, LA treatment improves of gait, walking speed, NCV, axons morphometry and MAP-2 expression in rats with sciatic nerve complete transection. These results suggest that LA can be a potential treatment for peripheral nerve injuries.
Asunto(s)
Hormona Liberadora de Gonadotropina/agonistas , Leuprolida/administración & dosificación , Regeneración Nerviosa/efectos de los fármacos , Traumatismos de los Nervios Periféricos/patología , Nervio Ciático/efectos de los fármacos , Nervio Ciático/lesiones , Animales , Axones/efectos de los fármacos , Axones/patología , Locomoción/efectos de los fármacos , Masculino , Traumatismos de los Nervios Periféricos/prevención & control , Ratas Wistar , Nervio Ciático/patologíaRESUMEN
Chemotherapy-induced peripheral neuropathic pain (CIPNP) is a frequent and devastating side effect of cancer therapy. No preventive strategies are currently available. We investigated the use of resveratrol (RESV) in the prevention of CIPNP and evaluated key components of the antioxidant defense system and neuroinflammatory factors as possible mediators contributing to RESV actions. Male rats were injected with oxaliplatin (OXA) and received daily oral RESV. Paw mechanical and thermal allodynia, oxidative stress, antioxidant, pro-inflammatory and neuronal injury/activation markers were evaluated in the sciatic nerve (SN), lumbar dorsal root ganglia (DRG) and spinal cord (SC). OXA-injected animals developed mechanical and thermal allodynia, while those receiving OXA + RESV showed patterns of response similar to control animals. Higher TBARS levels and lower GSH/GSSG ratios were observed in the SN of animals receiving OXA. The mRNA levels of the transcription factor NFκB and the pro-inflammatory cytokine TNFα were found to be upregulated both in lumbar DRG and SC. In addition, the antioxidant enzymes NQO-1 and HO-1 and the neuronal injury marker ATF3 showed increased levels of expression in lumbar DRG. In the dorsal SC the neuronal activation marker c-fos and the transcription factor Nrf2, main regulator of antioxidant defenses, were found to be upregulated. RESV early and sustained administration prevented NFκB, TNFα, ATF3 and c-fos upregulation, while increasing the expression of Nrf2, NQO-1, HO-1 and the redox-sensitive deacetylase SIRT1. RESV treatment was also able to restore TBARS levels and GSH/GSSG ratio. Thus, RESV administration resulted in the upregulation of antioxidant mediators, suppression of pro-inflammatory parameters and prevention of OXA-induced mechanical and thermal allodynia.
Asunto(s)
Antiinflamatorios/uso terapéutico , Antioxidantes/uso terapéutico , Hiperalgesia/prevención & control , Estrés Oxidativo/efectos de los fármacos , Resveratrol/uso terapéutico , Animales , Antiinflamatorios/farmacología , Antioxidantes/farmacología , Citocinas/metabolismo , Ganglios Espinales/efectos de los fármacos , Ganglios Espinales/metabolismo , Hiperalgesia/inducido químicamente , Hiperalgesia/metabolismo , Masculino , Oxaliplatino/efectos adversos , Dimensión del Dolor , Ratas , Resveratrol/farmacología , Nervio Ciático/efectos de los fármacos , Nervio Ciático/metabolismo , Médula Espinal/efectos de los fármacos , Médula Espinal/metabolismoRESUMEN
TRPM8 is the main ion channel responsible for cold transduction in the somatosensory system. Nerve terminal availability of TRPM8 determines cold sensitivity, but how axonal secretory organelles control channel delivery remains poorly understood. Here we examine the distribution of TRPM8 and trafficking organelles in cold-sensitive peripheral axons and disrupt trafficking by targeting the ARF-GEF GBF1 pharmacologically or the small GTPase RAB6 by optogenetics. In axons of the sciatic nerve, inhibition of GBF1 interrupts TRPM8 trafficking and increases association with the trans-Golgi network, LAMP1, and Golgi satellites, which distribute profusely along the axonal shaft. Accordingly, both TRPM8-dependent ongoing activity and cold-evoked responses reversibly decline upon GBF1 inhibition in nerve endings of corneal cold thermoreceptors. Inhibition of RAB6, which also associates to Golgi satellites, decreases cold-induced responses in vivo. Our results support a non-conventional axonal trafficking mechanism controlling the availability of TRPM8 in axons and cold sensitivity in the peripheral nervous system.
Asunto(s)
Axones/metabolismo , Frío , Orgánulos/metabolismo , Canales Catiónicos TRPM/metabolismo , Animales , Axones/efectos de los fármacos , Aparato de Golgi/efectos de los fármacos , Aparato de Golgi/metabolismo , Factores de Intercambio de Guanina Nucleótido/metabolismo , Células HEK293 , Células HeLa , Humanos , Masculino , Mentol/farmacología , Ratones , Optogenética , Orgánulos/efectos de los fármacos , Unión Proteica/efectos de los fármacos , Transporte de Proteínas/efectos de los fármacos , Nervio Ciático/efectos de los fármacos , Nervio Ciático/metabolismo , Termorreceptores/metabolismo , Proteínas de Unión al GTP rab/metabolismoRESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Luehea divaricata, popularly known in Brazil as "açoita-cavalo", has been widely explored by different ethnic groups native to Brazil to treat different pathologic conditions, including inflammatory pain. However, no report could be found on the effect that extract of L. divaricata has on neuropathic pain. This is an important topic because convergent and divergent mechanisms underlie inflammatory vs. neuropathic pain indicate that there may not always be a clear mechanistic delineation between these two conditions. AIM OF THE STUDY: The study aimed to determine antioxidant activity and macronutrient composition of aqueous extract from leaves of L. divaricata, and the effect of oral administration on nociception in rats with chronic constriction injury (CCI) of sciatic nerve-induced neuropathic pain, one of the most commonly employed animal models of neuropathic pain. MATERIALS AND METHODS: The antioxidant activity of the extract was evaluated by total phenolic content and DPPH, ABTSâ+ and ORAC methods. Vitexin was determined by HPLC to show that the composition of the extract of the present study is similar to that used in previous studies with this genus. Total sugar and sucrose concentrations were assessed by the anthrone method, while glucose and triacilglycerides were determined using commercially available kits. Fructose concentration was calculated from values for total sugars, glucose and sucrose. Total protein was determined by Bradford assay. The effect on DNA strand breaking was investigated by inhibition of strand breaking of supercoiled DNA by hydroxyl radical. The antinociceptive effects of aqueous extract (100, 300, 500, and 1000â¯mg/kg, i.g.) were evaluated on thermal and mechanical thresholds for neuropathic pain induced by chronic constriction injury (CCI) of the sciatic nerve in rats. We also compared the antinociceptive effect of the extract (500â¯mg/kg, i.g.) with that induced by gabapentin (50â¯mg/kg, i.g.), a first-line clinical treatment for neuropathic pain. The effect of co-administration of extract (500â¯mg/kg, i.g.) and low-dose gabapentin (30â¯mg/kg, i.g.) was also assessed. In addition, the effect of the extract on body weight, and blood and hepatic parameters were investigated to reveal possible side effects of treatment. RESULTS: The extract showed high content of total phenol; good reducing capacity for DPPH, ABTSâ+ and ORAC assays; presence of vitexin; and a high capacity to inhibit strand breaking of supercoiled DNA. The predominant sugar was sucrose, followed by glucose and fructose. Total protein was greater than triacylglycerides, with the latter being present in a trace amount in the extract. The extract increased the thermal and mechanical thresholds, which was reduced by CCI. The antinociceptive effect was comparable to gabapentin and was also found after co-administration of extract and low-dose gabapentin. No significant change was found in body weight and blood and hepatic indicators after extract treatment. CONCLUSIONS: Aqueous extract from L. divaricata leaves was as effective as gabapentin at attenuating CCI-induced neuropathic pain, indicating for first time the therapeutic potential of this species for this type of pain.
Asunto(s)
Malvaceae/química , Neuralgia/tratamiento farmacológico , Nocicepción/efectos de los fármacos , Extractos Vegetales/farmacología , Hojas de la Planta/química , Animales , Antioxidantes/farmacología , Brasil , Modelos Animales de Enfermedad , Hiperalgesia/tratamiento farmacológico , Masculino , Dimensión del Dolor/métodos , Ratas , Ratas Wistar , Nervio Ciático/efectos de los fármacos , Neuropatía Ciática/tratamiento farmacológicoRESUMEN
This study aimed to investigate the therapeutic effect of fasudil on treating experimental autoimmune neuritis (EAN). Twenty-four EAN mice were randomly assigned to fasudil treatment (Fasudil group) or saline treatment (EAN model group) for 28 days. Clinical symptom score was evaluated every other day; inflammatory cell infiltration, demyelination, anti-myelin basic protein (MBP), inflammatory cytokines, inducible nitric oxide synthase (iNOS), and arginase-1 were detected in sciatic nerves at day 28. Th1, Th2, Th17, and Tregs proportions in splenocytes were detected at day 28. Clinical symptom score was found to be attenuated in the Fasudil group compared to the EAN model group from day 12 to day 28. Sciatic nerve inflammatory cell counts by HE staining and demyelination by luxol fast blue staining were both reduced, while MBP was increased in the Fasudil group compared to the EAN model group at day 28. Interferon γ (IFN-γ) and interleukin (IL)-17 were reduced, while IL-4 and IL-10 were elevated in the Fasudil group at day 28. Sciatic nerve M1 macrophages marker iNOS was decreased while M2 macrophages marker arginase-1 was increased in the Fasudil group at day 28. CD4+IFN-γ+ (Th1) and CD4+IL-17+ (Th17) cell proportions were both decreased, CD4+IL-4+ (Th2) cell proportion was similar, while CD25+FOXP3+ (Treg) cell proportion in splenocytes was increased in the Fasudil group. In summary, fasudil presented a good therapeutic effect for treating EAN by attenuating Th1/Th17 cells and promoting Tregs activation as well as M2 macrophages polarization.
Asunto(s)
Animales , Femenino , Conejos , Interleucinas/sangre , Interferón gamma/sangre , Linfocitos T Colaboradores-Inductores/efectos de los fármacos , Neuritis Autoinmune Experimental/tratamiento farmacológico , Nervio Ciático/efectos de los fármacos , Nervio Ciático/metabolismo , Factores de Tiempo , Reacción en Cadena en Tiempo Real de la Polimerasa , ARN Mitocondrial , Ratones Endogámicos C57BL , Neuritis Autoinmune Experimental/sangreRESUMEN
PURPOSE: To evaluate the local nerve myelin recovery and the expression of PSD-95 protein and mRNA in the L4-L6 segment of the spinal cord after applying Brazilein to sciatic nerve injury BALB/c mice model and investigate the regulatory effects of Brazilein on myelin recovery after peripheral nerve injury. METHODS: A total of 160 BALB/c mice were selected to establish the unilateral sciatic nerve injury model and randomly divided into four groups: saline blank control, Brazilein high-dose, medium-dose, and low-dose. Mice were assessed at different time points (1 w, 2 w, 4 w, 8 w) after sciatic nerve injury for the sciatic functional index (SFI) and sciatic nerve function recovery of the injured side by myelin Luxol Fast Blue (LFB) staining of the sciatic nerve. In addition, immunohistochemistry, real time-PCR, and Western blot were used to detect the PSD-95 expression in the spinal cord L4-L6 segments of the injured sciatic nerve at each time point. RESULTS: The results of SFI and sciatic nerve function recovery, as well as, myelin LFB staining of the injured side indicated that all indexes of the Brazilein middle- and high-dose groups were significantly better than the low-dose and blank control groups at each time point. The PSD-95 expression in the L4-L6 segment of the spinal cord was statistically lower in the high- and medium-dose groups than in the low-dose and blank control groups at 1 w, 2 w, and 4 w, while the differences between the groups were not significant at 8 w. CONCLUSION: Brazilein inhibits PSD-95 activation in the corresponding segment of sciatic nerve spinal cord in BALB/c mice after sciatic nerve injury, thereby inhibiting the excessive expression of free radicals and promoting myelin regeneration.
Asunto(s)
Benzopiranos/uso terapéutico , Homólogo 4 de la Proteína Discs Large/antagonistas & inhibidores , Homólogo 4 de la Proteína Discs Large/biosíntesis , Indenos/uso terapéutico , Recuperación de la Función/fisiología , Neuropatía Ciática/tratamiento farmacológico , Neuropatía Ciática/metabolismo , Animales , Benzopiranos/farmacología , Homólogo 4 de la Proteína Discs Large/genética , Expresión Génica , Indenos/farmacología , Masculino , Ratones , Ratones Endogámicos BALB C , Regeneración Nerviosa/efectos de los fármacos , Regeneración Nerviosa/fisiología , Traumatismos de los Nervios Periféricos/tratamiento farmacológico , Traumatismos de los Nervios Periféricos/metabolismo , Recuperación de la Función/efectos de los fármacos , Nervio Ciático/efectos de los fármacos , Nervio Ciático/lesiones , Nervio Ciático/metabolismo , Neuropatía Ciática/genética , Resultado del TratamientoRESUMEN
Breast carcinoma causes severe pain, which decreases the quality of life of patients. Current treatments produce adverse effects and have limited efficacy. Transient potential receptor ankyrin 1 (TRPA1) is related to the onset of cancer and neuropathic pain. The aim of this study was to evaluate the involvement of TRPA1 in a model of breast carcinoma. We injected 4T1 cells in the fourth caudal mammary fat pad of female BALB/c mice, and after 20 days we observed mechanical and cold allodynia and spontaneous nociception behavior (mouse grimace scale detection, MGS). TRPA1 selective antagonist (HC-030031 or A-967079) administration or intrathecal administration of TRPA1 antisense (AS) oligonucleotide was performed. The activity of NADPH oxidase, superoxide dismutase (SOD) and hydrogen peroxide (H2O2) levels were evaluated. The chemical hyperalgesia produced by a TRPA1 agonist (allyl isothiocyanate, AITC) was also detected. The administration of TRPA1 antagonists, TRPA1 AS, or antioxidant, transiently attenuated MGS, or mechanical and cold allodynia. Intraplantar injection of AITC also caused nociception. NADPH oxidase or SOD activity and H2O2 levels were increased in the sciatic nerve and hind paw skin samples. The 4T1 cells did not express TRPA1, and the use of HC-030031 or α-lipoic acid did not reduce the cytotoxic effect of a chemotherapeutic drug (paclitaxel). Thus, TRPA1 could be investigated as a target for breast carcinoma pain treatment.
Asunto(s)
Dolor en Cáncer , Neoplasias Mamarias Experimentales , Canal Catiónico TRPA1 , Acetanilidas/farmacología , Acetanilidas/uso terapéutico , Analgésicos/uso terapéutico , Animales , Antineoplásicos Fitogénicos/farmacología , Dolor en Cáncer/tratamiento farmacológico , Dolor en Cáncer/etiología , Dolor en Cáncer/genética , Dolor en Cáncer/metabolismo , Línea Celular Tumoral , Femenino , Peróxido de Hidrógeno/metabolismo , Hiperalgesia/tratamiento farmacológico , Neoplasias Mamarias Experimentales/complicaciones , Neoplasias Mamarias Experimentales/tratamiento farmacológico , Neoplasias Mamarias Experimentales/genética , Neoplasias Mamarias Experimentales/metabolismo , Ratones Endogámicos BALB C , NADPH Oxidasas/metabolismo , Nocicepción/efectos de los fármacos , Oximas/uso terapéutico , Paclitaxel/farmacología , Purinas/farmacología , Purinas/uso terapéutico , Nervio Ciático/efectos de los fármacos , Nervio Ciático/metabolismo , Piel/metabolismo , Superóxido Dismutasa/metabolismo , Canal Catiónico TRPA1/antagonistas & inhibidores , Canal Catiónico TRPA1/genética , Ácido Tióctico/uso terapéuticoRESUMEN
This study aimed to investigate the therapeutic effect of fasudil on treating experimental autoimmune neuritis (EAN). Twenty-four EAN mice were randomly assigned to fasudil treatment (Fasudil group) or saline treatment (EAN model group) for 28 days. Clinical symptom score was evaluated every other day; inflammatory cell infiltration, demyelination, anti-myelin basic protein (MBP), inflammatory cytokines, inducible nitric oxide synthase (iNOS), and arginase-1 were detected in sciatic nerves at day 28. Th1, Th2, Th17, and Tregs proportions in splenocytes were detected at day 28. Clinical symptom score was found to be attenuated in the Fasudil group compared to the EAN model group from day 12 to day 28. Sciatic nerve inflammatory cell counts by HE staining and demyelination by luxol fast blue staining were both reduced, while MBP was increased in the Fasudil group compared to the EAN model group at day 28. Interferon γ (IFN-γ) and interleukin (IL)-17 were reduced, while IL-4 and IL-10 were elevated in the Fasudil group at day 28. Sciatic nerve M1 macrophages marker iNOS was decreased while M2 macrophages marker arginase-1 was increased in the Fasudil group at day 28. CD4+IFN-γ+ (Th1) and CD4+IL-17+ (Th17) cell proportions were both decreased, CD4+IL-4+ (Th2) cell proportion was similar, while CD25+FOXP3+ (Treg) cell proportion in splenocytes was increased in the Fasudil group. In summary, fasudil presented a good therapeutic effect for treating EAN by attenuating Th1/Th17 cells and promoting Tregs activation as well as M2 macrophages polarization.
Asunto(s)
1-(5-Isoquinolinesulfonil)-2-Metilpiperazina/análogos & derivados , Interferón gamma/sangre , Interleucinas/sangre , Neuritis Autoinmune Experimental/tratamiento farmacológico , Linfocitos T Colaboradores-Inductores/efectos de los fármacos , 1-(5-Isoquinolinesulfonil)-2-Metilpiperazina/administración & dosificación , Animales , Femenino , Ratones , Ratones Endogámicos C57BL , Neuritis Autoinmune Experimental/sangre , ARN Mitocondrial , Reacción en Cadena en Tiempo Real de la Polimerasa , Nervio Ciático/efectos de los fármacos , Nervio Ciático/metabolismo , Factores de TiempoRESUMEN
Since the start of the COVID-19 pandemic, several anesthetic societies have generated clinical recommendations for the perioperative management of these patients, including the Chilean Society of Anesthesiology. Among these recommendations, the advantages of regional anesthesia have been highlighted. In this article, we report and discuss the case of a 59-year-old patient with diabetes mellitus II, Chronic Arterial Hypertension, Gout, and Stage IV Chronic Renal Failure admitted with a multifocal septic condition characterized by suppurative collections including a large subcutaneous lumbar abscess recently drained. The patient evolved with left knee septic arthritis and was scheduled for arthroscopic irrigation and debridement. As per protocol a SARS-COV2 PCR was tested and resulted positive. It was decided to proceed to surgery under anesthetic ultrasound-guided femoral and sciatic nerve blocks using an adrenalized (2.5 ug/mL) solution of 0.33% Levobupivacaine- 0.66% Lidocaine (15 mL each). Fifteen minutes later, the knee was mobilized passively without pain. Surgery started after 30 minutes. The surgical and anesthetic conditions were described as adequate by the surgeon and the patient, respectively. The postoperative evolution was satisfactory without presenting respiratory symptoms and the patient was discharged 17 days after under oral antibiotic treatment.
Desde el comienzo de la pandemia de COviD-19, varias sociedades de anestesia han generado recomendaciones clínicas para el tratamiento perioperatorio de estos pacientes, incluida la Sociedad Chilena de Anestesiología. Entre estas recomendaciones, se han destacado las ventajas de la anestesia regional. En este artículo, reportamos y discutimos el caso de un paciente de 59 años con diabetes mellitus tipo 2, hipertensión arterial, gota e insuficiencia renal crónica en etapa IV, admitido por una sepsis multifocal caracterizada por colecciones supurativas que incluyen un gran absceso lumbar subcutáneo drenado recientemente. El paciente evolucionó con artritis séptica de rodilla requiriendo de una exploración y aseo artroscópico. Por protocolo perioperatorio COviD-19, se solicitó PCR para SARS-COv2 con un resultado positivo. Se decidió proceder a la cirugía bajo bloqueos anestésicos guiados por ultrasonido de nervios femoral y ciático utilizando una solución adrenalizada (2,5 ug/mL) de levobupivacaína al 0,33% lidocaína al 0,66% (15 mL en cada uno). Quince minutos después, la rodilla se movilizó pasivamente sin dolor. La cirugía se inició tras media hora empleando una ligera sedación con propofol. Las condiciones quirúrgicas y anestésicas fueron descritas como adecuadas por el cirujano y el paciente. Este último evolucionó favorablemente, sin síntomas respiratorios y fue dado de alta 17 días después con tratamiento antibiótico oral.
Asunto(s)
Humanos , Masculino , Persona de Mediana Edad , Artroscopía/métodos , Artritis Infecciosa/cirugía , COVID-19/complicaciones , Anestésicos Locales/administración & dosificación , Bloqueo Nervioso/métodos , Nervio Ciático/efectos de los fármacos , Artritis Infecciosa/complicaciones , Artritis Infecciosa/diagnóstico por imagen , Nervio Femoral/efectos de los fármacos , Articulación de la RodillaRESUMEN
Background: Nociceptive stimulation in orthopedic surgery requires effective pain management to ensure trans andpostoperative patient comfort. Several techniques can be used for this, and multimodal analgesia protocols such as guidedlocoregional blocks provide a balanced effect, as they enable the use of low-dose anesthetics and offer rapid recovery. Thebenefits of specific nerve blocks in domestic animals are well known; however, there are few reports that have ascertainedtheir safety in wild species. This report is aimed at describing the successful use of neurolocalizer-guided sciatic andfemoral nerve blocks during tibial osteosyntheses in a chinchilla.Case: A 9-month-old chinchilla weighing 0.56 kg was referred for surgery for proximal and mid-diaphyseal tibia fracturesresulting from trauma. Following preanesthetic evaluation, the animal received intramuscular dexmedetomidine (15 µgkg1) as preanesthetic medication. Sedation was apparent after 15 min and was verified by a decreased activity, the animalallowing manipulation, absence of the eyelid and righting reflexes, and limb movement after clamping removal of limbafter clamping. After achieving sedation, anesthesia was induced and maintained with sevoflurane (FiO2 = 1.0), suppliedthrough a nasoral mask. Sciatic and femoral nerve blocks were performed with the aid of a neurostimulator. A needle wasinserted into the femoral triangle, cranial to the femoral artery, and into the depression between the sciatic tuberosity andthe greater femoral trochanter. The neurostimulator was set at a pulse frequency of 1 Hz, pulse duration of 0.1 ms andinitial current of 0.6 mA. The needle was advanced toward the nerves until muscle contractions were observed, and thecurrent was gradually reduced until contractions were manifested at a minimum current...(AU)
Asunto(s)
Animales , Chinchilla , Nervios Periféricos/efectos de los fármacos , Dexmedetomidina/administración & dosificación , Nervio Ciático/efectos de los fármacos , Fijación Interna de Fracturas/veterinaria , Fracturas de la Tibia/cirugíaRESUMEN
En órganos dañados, el ácido láctico (AL) modifica la respuesta inmune innata e inflamatoria, induciendo una menor expresión de citoquinas pro-inflamatorias, que provocan, la modulación del reclutamiento de células inmunes. El daño por compresión del nervio isquiático (NI) desencadena una respuesta inflamatoria y un aumento exponencial del infiltrado inflamatorio de células inmunes, produciendo la destrucción de axones y pérdida funcional del nervio. El objetivo de este estudio es evaluar el efecto agudo de la inyección de AL, sobre la proporción de células inmunes en la fase inflamatoria temprana, en el sitio de lesión del NI post compresión. Para ello, se utilizaron 15 ratas machos Sprague Dawley adultas, en tres grupos de compresión nerviosa. Un grupo control, un grupo control negativo con placebo (100 µL PBS) y un grupo experimental con inyección de 100 µL de AL [20mM]. Al tercer día los NI se analizaron histológicamente y se estableció la proporción de células inmunes en el sitio de lesión. Los resultados muestran que la inyección intraneural de AL provoca una disminución en el porcentaje de linfocitos y un aumento en el porcentaje de macrófagos. Este es el primer trabajo de inyección intraneural de AL y demuestra el efecto modulador del AL sobre las células inmunes en el sistema nervioso periférico.
In damaged organs, lactic acid (LA) modifies the innate and inflammatory immune response, inducing a lower expression of pro-inflammatory cytokines, which provoke the modulation of immune cell recruitment. Damage by compression of the sciatic nerve (SN) triggers an inflammatory response and an exponential increase in the inflammatory infiltrate of immune cells, producing the destruction of axons and functional loss of the nerve. The objective of this study is to evaluate the acute effect of the injection of LA, on the proportion of immune cells in the early inflammatory phase, in the site of SN post-compression injury. For this, 15 adult Sprague Dawley rats were used in three groups of nervous compression. A control group, a negative control group with placebo (100 mL PBS) and an experimental group with injection of 100 mL of LA [20mM]. On the third day, the SNs were histologically analyzed and the proportion of immune cells at the injury site was established. The results show that the intraneural injection of LA causes a decrease in the percentage of lymphocytes and an increase in the percentage of macrophages. This is the first work of intraneural injection of LA and demonstrates the modulating effect of LA on immune cells in the peripheral nervous system.
Asunto(s)
Animales , Masculino , Ratas , Nervio Ciático/efectos de los fármacos , Nervio Ciático/inmunología , Ácido Láctico/farmacología , Síndromes de Compresión Nerviosa/patología , Nervio Ciático/patología , Linfocitos/efectos de los fármacos , Citocinas/inmunología , Citocinas/metabolismo , Ratas Sprague-Dawley , Ácido Láctico/administración & dosificación , Inflamación/inmunología , Macrófagos/efectos de los fármacosRESUMEN
Trauma to the peripheral nervous system (PNS) results in loss of motor and sensory functions. After an injury, a complex series of events begins, allowing axonal regeneration and target reinnervation. However, this regenerative potential is limited by several factors such as age, distance from the lesion site to the target and severity of lesion. Many studies look for ways to overcome these limitations. Inosine, a purine nucleoside derived from adenosine, emerges as a potential treatment, due to its capacity to regulate axonal growth, neuroprotection and immunomodulation, contributing to motor recovery. However, no studies demonstrated their effects on PNS. C57/Black6 mice were submitted to sciatic nerve crush and received intraperitoneal injections of saline or inosine (70â¯mg/kg), one hour after injury and daily for one week. To evaluate axonal regeneration and functional recovery, electroneuromyography, Sciatic Function Index (SFI), rotarod and pinprick tests were performed. Our results showed that the inosine group presented a higher number of myelinated fibers and a large amount of fibers within the ideal G-ratio. In addition, the results of electroneuromyography showed greater amplitude of the compound muscle action potentials in the first and second weeks, suggesting anticipation of regeneration in the inosine group. We also observed in the inosine group, motor and sensory neurons survival, reduction in the number of macrophages and myelin ovoids in the sciatic nerves, and an early recovery of motor and sensory functions. Thus, we conclude that the use of inosine accelerates axonal regeneration promoting an early recovery of motor and sensory functions.