RESUMO
Chemotherapy-induced neuropathic pain is a common dose-limiting side effect of anticancerdrugs but lacks an effective treatment strategy. Scolopendra subspinipes has been used in traditional medicine to treat chronic neuronal diseases. Moreover, pharmacopuncture with S subspinipes (SSP) produces potent analgesia in humans and experimental animals. In this study, we examined the effect of SSP into the ST36 acupoint on oxaliplatin-induced mechanical allodynia in mice. Acupoint treatment with SSP (0.5%/20 µL) significantly decreased mechanical allodynia produced by a single oxaliplatin injection (10mg/kg i.p.), which was completely prevented by acupoint preinjection of lidocaine. Intrathecal treatment with yohimbine (25 µg/5 µL), an α2-adrenoceptor antagonist, prevented the anti-allodynic effect of SSP. In contrast, a high dose (0.1mg/kg i.p.) ofclonidine,an α2-adrenoceptor agonist, suppressed oxaliplatin-induced mechanical allodynia butproduced severe side effects including hypotension, bradycardia, and motor impairment. The combination of SSP with a lower dose of clonidine (0.03 mg/kg) produced a comparable analgesic effect without side effects. Collectively, our findings demonstrate that SSP produces an analgesic effect in oxaliplatin-induced pain via neuronal conduction at the acupoint and activation of spinal α2-adrenoceptors. Moreover, acombination of low-dose clonidine with SSP represents a novel and safe therapeutic strategy for chemotherapy-induced chronic pain. PERSPECTIVE: SSP can relieve oxaliplatin-induced mechanical allodynia. Moreover, SSP potentiates clonidine-induced anti-allodynia, allowing a lower dose of clonidine with no significant side effects. The combination of SSP and low-dose clonidine might provide a novel strategy for the management of chemotherapy-induced peripheral neuropathy.
Assuntos
Venenos de Artrópodes/farmacologia , Hiperalgesia , Neuralgia , Pontos de Acupuntura , Analgésicos/farmacologia , Animais , Antineoplásicos/toxicidade , Clonidina/farmacologia , Hiperalgesia/induzido quimicamente , Hipotensão , Masculino , Camundongos , Transtornos Motores , Neuralgia/induzido quimicamente , Neuralgia/prevenção & controle , Oxaliplatina/toxicidadeRESUMO
Unlike in the central nervous system (CNS), in the adult peripheral nervous system (PNS), activation of GABAA receptors (GABAAR) is excitatory because of the relatively high concentration of intracellular chloride in these neurons. Indeed, exogenous GABA and muscimol, a GABAAR agonist, exacerbate acute inflammatory hypersensitivity in rodents. However, it remains unclear whether peripheral GABAAR and the endogenous GABA play an important role in persistent inflammatory hypersensitivity. In this study, we thus investigated how peripheral GABAAR affects pain hypersensitivity by using the complete Freund's adjuvant (CFA)-induced persistent inflammatory pain mouse model. We found that intraplantar (i.pl.) administration of GABAAR antagonists, picrotoxin, and 1(S),9(R)-(-)-bicuculline methiodide significantly inhibited both spontaneous nociceptive (paw licking and flinching) behavior and mechanical hypersensitivity in CFA-injected mice at day 3 (D3), but not in naïve mice. Interestingly, CFA-induced mechanical hypersensitivity was significantly reversed by anti-GABA antibody (anti-GABA, i.pl.). In addition, RT-qPCR revealed that glutamate decarboxylase Gad1 (GAD 67) and Gad2 (GAD 65) mRNA expression was also upregulated in the ipsilateral hind paw of CFA-injected mice at D3. Finally, 5α-pregnan-3α-ol-20-one (3α,5α-THP), a selective positive allosteric modulator of GABAAR, produced mechanical hypersensitivity in naïve mice in a dose-dependent manner. Taken together, our results indicate that peripheral GABAAR and endogenous GABA, possibly produced by the inflamed tissue, potentiate CFA-induced persistent inflammatory hypersensitivity, suggesting that they can be used as a therapeutic target for alleviating inflammatory pain.
Assuntos
Hiperalgesia/metabolismo , Inflamação/metabolismo , Receptores de GABA-A/metabolismo , Animais , Anticorpos/farmacologia , Adjuvante de Freund , Agonistas de Receptores de GABA-A/farmacologia , Antagonistas de Receptores de GABA-A/farmacologia , Glutamato Descarboxilase/metabolismo , Hiperalgesia/tratamento farmacológico , Inflamação/tratamento farmacológico , Masculino , Camundongos Endogâmicos C57BL , Dor Nociceptiva/tratamento farmacológico , Dor Nociceptiva/metabolismo , RNA Mensageiro/metabolismo , Distribuição Aleatória , Tato , Ácido gama-Aminobutírico/imunologia , Ácido gama-Aminobutírico/metabolismoRESUMO
Sinomenium acutum has been used in traditional medicine to treat a painful disease such as rheumatic arthritis and neuralgia. Sinomenine, which is a main bioactive ingredient in Sinomenium acutum, has been reported to have an analgesic effect in diverse pain animal models. However little is known about the detailed mechanisms underlying peripheral analgesic effect of sinomenine. In the present study, we aimed to elucidate its cellular mechanism by using formalin-induced acute inflammatory pain model in mice. We found that intraperitoneal (i.p.) administration of sinomenine (50mg/kg) suppressed formalin-induced paw licking behavior in both the first and the second phase. Formalin-induced c-Fos protein expression was also suppressed by sinomenine (50mg/kg i.p.) in the superficial dorsal horn of spinal cord. Whole-cell patch-clamp recordings from small-sized dorsal root ganglion (DRG) neurons revealed that sinomenine reversibly increased the spike threshold and the threshold current intensity for evoking a single spike and decreased firing frequency of action potentials evoked in response to a long current pulse. Voltage-gated sodium currents (INa) were also significantly reduced by sinomenine in a dose-dependent manner (IC50=2.3±0.2mM). Finally, we confirmed that intraplantar application of sinomenine suppressed formalin-induced pain behavior only in the first phase, but not the second phase. Taken together, our results suggest that sinomenine has a peripheral analgesic effect by inhibiting INa.
Assuntos
Antirreumáticos/uso terapêutico , Morfinanos/uso terapêutico , Dor/tratamento farmacológico , Sódio/farmacologia , Animais , Células Cultivadas , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Formaldeído/toxicidade , Gânglios Espinais/citologia , Inflamação/complicações , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neuralgia , Dor/etiologia , Medição da Dor , Técnicas de Patch-Clamp , Proteínas Proto-Oncogênicas c-fos/metabolismo , Células Receptoras Sensoriais/efeitos dos fármacos , Células Receptoras Sensoriais/metabolismo , Canais de Sódio Disparados por Voltagem/metabolismoRESUMO
UNLABELLED: The chemotherapeutic agent, oxaliplatin, produces a robust painful neuropathy that results in the loss of intraepidermal nerve fibers (IENFs). We have previously reported that an acupuncture point (acupoint) injection of diluted bee venom (DBV) produces a temporary antiallodynic effect in oxaliplatin-induced neuropathic mice. Herein we show a significant long-lasting antinociceptive effect of repetitive DBV acupoint treatment on oxaliplatin-induced mechanical allodynia and a significant reduction in the loss of IENFs. DBV (0.1 mg/kg, subcutaneous) was administered once a day for 18 days beginning on day 15 after oxaliplatin injection. Immunohistochemistry for IENF was performed on the glabrous skin of the hind paw footpad using the pan-neuronal marker, protein gene product 9.5. A temporary increase in mechanical threshold was observed 60 minutes after a single DBV injection into the Zusanli acupoint, and this effect was enhanced over time with repetitive DBV treatments. The basal mechanical threshold before daily DBV injection also increased from day 7 after DBV injections, and peaked at day 14 after DBV treatment. Moreover, the oxaliplatin-induced loss of IENFs was significantly reduced in mice treated repetitively with DBV. Repetitive pretreatment with the α-2 adrenoceptor antagonist, yohimbine, (5 mg/kg, subcutaneous) completely prevented the antiallodynic effects and the increase in IENFs observed in mice treated repetitively with DBV. PERSPECTIVE: We showed that repetitive acupoint stimulation with DBV gradually and significantly reduced oxaliplatin-induced mechanical allodynia and restored the loss of IENFs in neuropathic mice via an α-2 adrenoceptor mechanism. Collectively, results of this study suggest that repetitive acupoint treatment with DBV can be a potential strategy for the management of chemotherapy-induced neuropathy.
Assuntos
Terapia por Acupuntura/métodos , Analgésicos/administração & dosagem , Venenos de Abelha/administração & dosagem , Hiperalgesia/terapia , Fibras Nervosas/patologia , Doenças do Sistema Nervoso Periférico/terapia , Pontos de Acupuntura , Antagonistas de Receptores Adrenérgicos alfa 2/farmacologia , Animais , Modelos Animais de Doenças , Epiderme/efeitos dos fármacos , Epiderme/inervação , Epiderme/patologia , Pé/inervação , Pé/patologia , Hiperalgesia/patologia , Hiperalgesia/fisiopatologia , Masculino , Camundongos Endogâmicos C57BL , Compostos Organoplatínicos , Oxaliplatina , Dor/patologia , Dor/fisiopatologia , Limiar da Dor/efeitos dos fármacos , Limiar da Dor/fisiologia , Doenças do Sistema Nervoso Periférico/patologia , Doenças do Sistema Nervoso Periférico/fisiopatologia , Distribuição Aleatória , Receptores Adrenérgicos alfa 2/metabolismo , Tato , Ioimbina/farmacologiaRESUMO
Oxaliplatin, which is used as one of anti-cancer drugs, commonly induces peripheral neuropathic pain. We have previously reported that an injection of diluted bee venom (DBV) produced a significant anti-nociceptive effects in several pain models of mice or rats. In this study, we evaluated time- and dose-dependent development of oxaliplatin-induced mechanical allodynia in bilateral hind paws of mice, and investigated the effect of DBV injection on this mechanical allodynia. DBV (0.1 mg/kg) was subcutaneously injected into the Zusanli acupoint 2 weeks after oxaliplatin (10 mg/kg) injection. One hour after DBV injection, we observed a significant reduction of mechanical allodynia in the ipsilateral hind paw, but not in the contralateral hind paw to DBV injection site. We subsequently examined whether this effect of DBV was related to the activation of peripheral nerves in DBV injected site, and then whether it was mediated by the activation of spinal cord alpha-2 adrenoceptors or opioid receptors. Subcutaneous pre-injection of 2% lidocaine (40 mg/kg) into the Zusanli acupoint completely blocked the anti-allodynic effect of DBV. Intrathecal pretreatment with yohimbine (25 µg/mouse), an alpha-2 adrenoceptor antagonist, also prevented the anti-allodynic effect of DBV, whereas pretreatment with naloxone (20 µg/mouse), an opioid receptor antagonist, did not block the effect of DBV. Taken together, these findings demonstrate that DBV injection into the Zusanli acupoint significantly reduces ipsilateral mechanical allodynia generated by oxaliplatin in mice, and also suggest that this anti-allodynic effect is dependent on the peripheral nerve activation in injected site and spinal cord alpha-2 adrenoceptors.
Assuntos
Analgésicos/uso terapêutico , Venenos de Abelha/uso terapêutico , Hiperalgesia/tratamento farmacológico , Neuralgia/tratamento farmacológico , Antagonistas de Receptores Adrenérgicos alfa 2/farmacologia , Animais , Injeções , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neuralgia/induzido quimicamente , Compostos Organoplatínicos/efeitos adversos , Oxaliplatina , Receptores Adrenérgicos alfa 2/fisiologia , Ioimbina/farmacologiaRESUMO
UNLABELLED: We previously demonstrated that a single injection of diluted bee venom (DBV) temporarily alleviates thermal hyperalgesia, but not mechanical allodynia, in neuropathic rats. The present study was designed to determine whether repetitive injection of DBV produces more potent analgesic effects on neuropathy-induced nociception and whether those effects are associated with increased neuronal activity in the locus coeruleus (LC) and with the suppression of spinal NMDA receptor NR1 subunit phosphorylation (pNR1). DBV (.25 mg/kg) was administered subcutaneously twice a day for 2 weeks beginning on day 15 post-chronic constrictive injury surgery. Pain responses were examined and potential changes in LC Fos expression and spinal pNR1 expression were determined. Repetitive DBV administration significantly reduced mechanical allodynia, as well as thermal hyperalgesia. The activity of LC noradrenergic neurons was increased and spinal pNR1 expression was significantly suppressed by repetitive DBV as compared with those of vehicle or single DBV injection. These suppressive effects of repetitive DBV on neuropathic pain and spinal pNR1 were prevented by intrathecal pretreatment of idazoxan, an alpha-2 adrenoceptor antagonist. These results indicate that repetitive DBV produces potent analgesic effects on neuropathic pain and this is associated with the activation of the LC noradrenergic system and with a reduction in spinal pNR1. PERSPECTIVE: The results of current study demonstrate that repetitive administration of DBV significantly suppresses neuropathic pain. Furthermore, this study provides mechanistic information that repetitive treatment of DBV can produce more potent analgesic effect than single DBV treatment, indicating a potential novel strategy for the management of chronic pain.
Assuntos
Neurônios Adrenérgicos/efeitos dos fármacos , Analgésicos não Narcóticos/administração & dosagem , Venenos de Abelha/administração & dosagem , Locus Cerúleo/patologia , Receptores de N-Metil-D-Aspartato/metabolismo , Ciática , Neurônios Adrenérgicos/ultraestrutura , Antagonistas de Receptores Adrenérgicos alfa 2/farmacologia , Análise de Variância , Animais , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Esquema de Medicação , Regulação da Expressão Gênica/efeitos dos fármacos , Idazoxano/farmacologia , Masculino , Microscopia Imunoeletrônica , Atividade Motora/efeitos dos fármacos , Proteínas Oncogênicas v-fos/metabolismo , Medição da Dor , Fosforilação/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Tempo de Reação/efeitos dos fármacos , Teste de Desempenho do Rota-Rod , Ciática/tratamento farmacológico , Ciática/metabolismo , Ciática/patologia , Fatores de Tempo , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
Spinal astrocytes have emerged as important mechanistic contributors to pathological and chronic pain. Recently, we have demonstrated that injection of diluted bee venom (DBV) into the Zusanli (ST36) acupoint produces a potent anti-nociceptive effect via the activation of spinal alpha-2 adrenoceptors. However, it is unclear if this anti-nociceptive effect is associated with alterations in spinal astrocytes. Thus, the present study was designed to determine: (1) whether DBV's anti-nociceptive effect in the formalin test involves suppression of spinal astrocyte activation; (2) whether DBV-induced astrocyte inhibition is mediated by spinal alpha-2 adrenoceptors; and (3) whether this glial modulation is potentiated by intrathecal administration of the glial metabolic inhibitor, fluorocitrate (FC) in combination with DBV injection. DBV was injected directly into the ST36 acupoint, and spinal expression of the astrocytic marker, glial fibrillary acidic protein (GFAP), was assessed together with effects on formalin-induced nociception. DBV treatment reduced pain responses in the late phase of the formalin test and significantly blocked the formalin-evoked increase in spinal GFAP expression. These effects of DBV were prevented by intrathecal pretreatment with selective alpha-2A and alpha-2C adrenoceptor antagonists. Moreover, low dose intrathecal injection of FC in conjunction with low dose DBV injection into the ST36 acupoint synergistically suppressed pain responses and GFAP expression. These results demonstrate that DBV stimulation of the ST36 acupoint inhibits the formalin-induced activation of spinal astrocytes and nociceptive behaviors in this inflammatory pain model and this inhibition is associated with the activation of spinal alpha-2 adrenoceptors.
Assuntos
Pontos de Acupuntura , Astrócitos/metabolismo , Formaldeído/farmacologia , Dor/induzido quimicamente , Receptores Adrenérgicos alfa 2/metabolismo , Medula Espinal/citologia , Antagonistas de Receptores Adrenérgicos alfa 2/farmacologia , Analgésicos/farmacologia , Analgésicos/uso terapêutico , Animais , Astrócitos/citologia , Astrócitos/efeitos dos fármacos , Venenos de Abelha/administração & dosagem , Venenos de Abelha/farmacologia , Citratos/administração & dosagem , Citratos/farmacologia , Proteína Glial Fibrilar Ácida/metabolismo , Idazoxano/farmacologia , Imidazóis/farmacologia , Injeções Espinhais , Isoindóis/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Dor/tratamento farmacológico , Manejo da Dor/métodos , Medição da Dor/métodos , Estimulação QuímicaRESUMO
UNLABELLED: Although intrathecal (i.t.) administration of the alpha(2)-adrenoceptor agonist clonidine has a pronounced analgesic effect, the clinical use of clonidine is limited by its side effects. Previously, our laboratory has demonstrated that the subcutaneous injection of diluted bee venom (DBV) into an acupoint (termed apipuncture) produces significant analgesic effect in various pain animal models. The present study was designed to examine whether DBV injection into the Zusanli acupoint (ST-36) could enhance lower-dose clonidine-induced analgesic effects without the development of hypotension, bradycardia, or sedation. In the mouse formalin test, DBV injection produced a dramatic leftward shift in the dose-response curve for clonidine-induced analgesia. In a rat neuropathic pain model i.t. clonidine dose dependently suppressed chronic constriction injury (CCI)-induced mechanical allodynia and thermal hyperalgesia, and this clonidine-induced analgesic effect was significantly potentiated by apipuncture pretreatment. DBV apipuncture alone or in combination with a low dose of i.t. clonidine produced an analgesic effect similar to that of the high dose of clonidine, but without significant side effects. The analgesic effect produced by the combination of i.t. clonidine and apipuncture was completely blocked by pretreatment with an alpha(2)-adrenoceptor antagonist. These data show that DBV-apipuncture significantly enhances clonidine-induced analgesia and suggest that a combination of low dose clonidine with acupuncture therapy represents a novel strategy for pain management that could eliminates clonidine's side effects. PERSPECTIVE: This study demonstrated that intrathecal clonidine-induced analgesia is significantly enhanced when it is combined with chemical acupuncture treatment. The administration of low-dose clonidine in combination with acupuncture produced a potent analgesic effect without significant side effects and thus represents a potential novel strategy for the management of chronic pain.
Assuntos
Pontos de Acupuntura , Analgésicos/uso terapêutico , Venenos de Abelha/uso terapêutico , Clonidina/uso terapêutico , Hiperalgesia/tratamento farmacológico , Medição da Dor , Dor/tratamento farmacológico , Analgésicos/efeitos adversos , Animais , Venenos de Abelha/administração & dosagem , Clonidina/administração & dosagem , Clonidina/efeitos adversos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Hiperalgesia/induzido quimicamente , Injeções Espinhais , Injeções Subcutâneas , Masculino , Camundongos , Camundongos Endogâmicos ICR , Dor/induzido quimicamente , Dor/fisiopatologia , Medição da Dor/métodos , Ratos , Ratos Sprague-DawleyRESUMO
Ursolic acid (UA) is pentacyclic triterpenoic acid that naturally occurs in many medicinal herbs and plants. In this study, we examined the possible suppressive effect of UA extracted from Oldenlandia diffusa on zymosan-induced acute inflammation in mice and complete Freund's adjuvant (CFA)-induced arthritis in rats. UA treatment (per oral) dose-dependently (25-200 mg kg(-1)) suppressed zymosan-induced leucocyte migration and prostaglandin E2 (PGE(2)) production in the air pouch exudates. Since the maximal effective dose of UA was 50 mg kg(-1) in the zymosan experiment, we used this dose of UA in a subsequent study using an adjuvant-induced rheumatoid arthritis model. UA treatment (50 mg kg(-1), per oral, once a day for 10 days) was started from day 12 after adjuvant injection. UA dramatically inhibited paw swelling, plasma PGE(2) production and radiological changes in the joint caused by CFA injection. Moreover, UA significantly suppressed the arthritis-induced mechanical and thermal hyperalgesia as well as the spinal Fos expression, as determined by immunohistochemistry, which was increased by CFA injection. In addition, overall anti-arthritic potency of UA was comparable with ibuprofen (100 mg kg(-1), oral) while UA did not induce significant gastric lesions as compared with the ibuprofen treatment group. These findings strongly suggest that UA is a useful suppressive compound for rheumatoid arthritis treatment with low risk of gastric problems.
Assuntos
Antirreumáticos/uso terapêutico , Artrite Experimental/tratamento farmacológico , Inflamação/tratamento farmacológico , Triterpenos/uso terapêutico , Doença Aguda , Animais , Antirreumáticos/química , Artrite Experimental/fisiopatologia , Movimento Celular/efeitos dos fármacos , Doença Crônica , Dinoprostona/biossíntese , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Inflamação/induzido quimicamente , Inflamação/fisiopatologia , Leucócitos/citologia , Leucócitos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos ICR , Oldenlandia/química , Dor/fisiopatologia , Dor/prevenção & controle , Extratos Vegetais/química , Extratos Vegetais/uso terapêutico , Ratos , Ratos Sprague-Dawley , Triterpenos/química , Zimosan , Ácido UrsólicoRESUMO
Although the frequency-dependent antinociceptive mechanisms of electroacupuncture (EA) have been well demonstrated, the anti-inflammatory mechanisms that underlie the suppressive effects induced by different frequencies of EA stimulation on peripheral inflammation are largely unknown. We have previously reported that EA stimulation can activate the sympathetic nervous system (SNS) and that this activation is responsible for the EA-induced suppression of zymosan-induced leukocyte migration. The present study was designed to evaluate the differential effect of low (1Hz, LF EA) versus high (120Hz, HF EA) frequency EA stimulation on SNS activation and ultimately on carrageenan-induced inflammation. Immediately after carrageenan injection, we applied either LF EA or HF EA bilaterally to the Zusanli (ST36) acupoints. To evaluate the anti-inflammatory effect of EA (EA-AI), paw volume and myeloperoxidase (MPO) activity, a marker of infiltrated leukocytes, were measured and the paw withdrawal latency to noxious heat stimulation was also assessed. Both LF EA and HF EA significantly suppressed the carrageenan-induced paw edema and MPO activity. Moreover, thermal hyperalgesia was strongly attenuated in both the LF EA and HF EA groups. Adrenalectomy significantly diminished HF EA-AI without affecting LF EA-AI. Pretreatment with the corticosterone receptor antagonist, RU-486 did not affect either LF EA- or HF EA-AI. On the other hand, administration of 6-hydroxydopamine (a neurotoxin for peripheral sympathetic nerve endings) selectively blocked LF EA-AI. Propranolol (a beta-adrenoceptor antagonist) completely abolished both LF EA- and HF EA-AI. The results of this study suggest that the suppressive effects of LF EA on carrageenan-induced paw inflammation are mediated by sympathetic post-ganglionic neurons, while the suppressive effects of HF EA are mediated by the sympatho-adrenal medullary axis.
Assuntos
Medula Suprarrenal/fisiologia , Estimulação Elétrica/métodos , Eletroacupuntura/métodos , Gânglios Simpáticos/patologia , Inflamação/patologia , Inflamação/terapia , Neurônios/efeitos da radiação , Medula Suprarrenal/efeitos da radiação , Adrenalectomia , Adrenérgicos/administração & dosagem , Animais , Carragenina , Modelos Animais de Doenças , Relação Dose-Resposta à Radiação , Edema/induzido quimicamente , Edema/patologia , Antagonistas de Hormônios/administração & dosagem , Inflamação/induzido quimicamente , Masculino , Camundongos , Camundongos Endogâmicos ICR , Mifepristona/administração & dosagem , Neurônios/fisiologia , Limiar da Dor/efeitos dos fármacos , Limiar da Dor/fisiologia , Limiar da Dor/efeitos da radiação , Peroxidase/metabolismo , Fatores de TempoRESUMO
Our recent data, obtained using a zymosan-induced inflammatory air pouch model in mice, have demonstrated that subcutaneous bee venom (BV) injection into the hind limb selectively activates the contralateral brain stem locus coeruleus (LC) and then via a descending noradrenergic pathway and subsequent adrenal medullary catecholamine release induces a potent anti-inflammatory effect. While the efferent limb of this BV-induced neuroimmune anti-inflammatory pathway is well documented, the afferent limb of this pathway is poorly understood. In particular the spinal mechanisms involved with BV activation of the LC are currently unknown. Spinal nitric oxide (NO) and its synthase (NOS) have been shown to play an important role in the transmission and amplification of neuronal information from the spinal cord to the brain stem. In the present study we evaluated whether spinal NO plays a role in BV-induced LC activation, since we have previously shown that LC activation underlies this 'BV-induced anti-inflammatory effect' (BVAI) using the mouse air pouch model. Intrathecal (i.t.) pretreatment with l-nitro arginine methyl ester (l-NAME, non-selective NOS inhibitor), hemoglobin (NO scavenger) or 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, soluble guanylate cyclase inhibitor) abolished BVAI on zymosan-induced leukocyte migration into the air pouch. Moreover, i.t. injection of l-N-iminoethyl-lysine (l-NIL, inducible NOS inhibitor), but not 7-nitroindazole (7-NI, neuronal NOS inhibitor), also inhibited BVAI. BV injection significantly increased both the number of Fos immunoreactive neurons and tyrosine hydroxylase-Fos double labeling neurons in the contralateral LC in zymosan-induced inflamed mice. Importantly this increase in Fos expression in the LC was also completely inhibited by i.t. injection of l-NIL, but not by i.t. injection of 7-NI. Collectively these results indicate that spinal NO generated from inducible NOS is involved in the BV-induced LC activation that underlies BVAI.
Assuntos
Anti-Inflamatórios/uso terapêutico , Venenos de Abelha/uso terapêutico , Locus Cerúleo/enzimologia , Óxido Nítrico/metabolismo , Doenças do Sistema Nervoso Periférico/tratamento farmacológico , Medula Espinal/enzimologia , Animais , Modelos Animais de Doenças , Interações Medicamentosas , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Indazóis/farmacologia , Leucócitos/efeitos dos fármacos , Locus Cerúleo/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos ICR , NG-Nitroarginina Metil Éster/farmacologia , Vias Neurais/efeitos dos fármacos , Vias Neurais/enzimologia , Proteínas Oncogênicas v-fos/metabolismo , Medula Espinal/efeitos dos fármacos , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
Electroacupuncture (EA) is used to treat a variety of inflammatory diseases; however, the neurophysiological mechanisms underlying EA's anti-inflammatory effect remain unclear. Accumulating evidence suggests that the sympathetic nervous system regulates immunologic and inflammatory responses and thus we hypothesized that this system could be involved in EA's anti-inflammatory effect (EA-AI). The goal of the present study was to evaluate whether the sympathetic nervous system plays a critical role in EA-AI using a mouse air pouch inflammation model. We found that bilateral low-frequency (1 Hz) EA applied to the Zusanli acupoint significantly suppressed the number of zymosan-induced leukocytes migrating into the air pouch. Furthermore, double-labeling immunohistochemical experiments showed that EA stimulation increased Fos expression in choline acetyltransferase (ChAT)-positive sympathetic pre-ganglionic neurons in the intermediolateral region of thoracic spinal cord segments. Chemical sympathetic denervation by intraperitoneal injection of 6-hydroxydopamine (which spares sympathetic adrenal medullary innervation) significantly inhibited EA-AI. In contrast, adrenalectomy did not alter EA-AI. Finally, systemic propranolol administration significantly inhibited EA's anti-inflammatory effect, suggesting that beta-adrenoceptors are involved. Collectively, these results suggest that EA produces an anti-inflammatory effect in this mouse air pouch model by activating the sympathetic nervous system leading to the release of catecholamines from post-ganglionic nerve terminals, which act on beta-adrenoceptors on immune cells to inhibit their migration.
Assuntos
Eletroacupuntura/métodos , Inflamação/fisiopatologia , Inflamação/terapia , Pele/inervação , Pele/fisiopatologia , Fibras Simpáticas Pós-Ganglionares/metabolismo , Acetilcolinesterase/metabolismo , Antagonistas Adrenérgicos beta/farmacologia , Animais , Catecolaminas/metabolismo , Quimiotaxia de Leucócito/efeitos dos fármacos , Quimiotaxia de Leucócito/fisiologia , Modelos Animais de Doenças , Eletroacupuntura/normas , Inflamação/induzido quimicamente , Mediadores da Inflamação/efeitos adversos , Masculino , Camundongos , Camundongos Endogâmicos ICR , Neurônios/metabolismo , Terminações Pré-Sinápticas/metabolismo , Pele/efeitos dos fármacos , Medula Espinal/metabolismo , Simpatectomia Química/métodos , Zimosan/efeitos adversosRESUMO
UNLABELLED: Peripheral bee venom (BV) administration produces 2 contrasting effects, nociception and antinociception. This study was designed to evaluate whether the initial nociceptive effect induced by BV injection into the Zusanli acupoint is involved in producing the more prolonged antinociceptive effect observed in the mouse formalin test, and whether capsaicin-sensitive primary afferents are involved in these effects. BV injection into the Zusanli point increased spinal Fos expression but not spontaneous nociceptive behavior. BV pretreatment 10 minutes before intraplantar formalin injection dose-dependently attenuated nociceptive behavior associated with the second phase of the formalin test. The destruction of capsaicin-sensitive primary afferents by resiniferatoxin (RTX) pretreatment selectively decreased BV-induced spinal Fos expression but did not affect BV-induced antinociception. Furthermore, BV injection increased Fos expression in tyrosine hydroxylase immunoreactive neurons in the locus caeruleus, and this expression was unaltered by RTX pretreatment. Finally, BV's antinociception was blocked by intrathecal injection of 10 microg idazoxan, and this effect was not modified by RTX pretreatment. These findings suggest that subcutaneous BV stimulation of the Zusanli point activates central catecholaminergic neurons via capsaicin-insensitive afferent fibers without induction of nociceptive behavior. This in turn leads to the activation of spinal alpha2-adrenoceptors, which ultimately reduces formalin-evoked nociceptive behaviors. PERSPECTIVE: This study demonstrates that BV acupuncture produces a significant antinociception without nociceptive behavior in rodents, which is mediated by capsaicin-insensitive afferents and involves activation of central adrenergic circuits. These results further suggest that BV stimulation into this acupuncture point might be a valuable alternative to traditional electrical or mechanical acupoint stimulation.
Assuntos
Analgesia por Acupuntura/métodos , Vias Aferentes/efeitos dos fármacos , Venenos de Abelha/farmacologia , Neurônios Aferentes/efeitos dos fármacos , Nociceptores/efeitos dos fármacos , Dor/tratamento farmacológico , Analgesia por Acupuntura/normas , Pontos de Acupuntura , Vias Aferentes/fisiologia , Analgésicos/farmacologia , Analgésicos/uso terapêutico , Animais , Venenos de Abelha/uso terapêutico , Capsaicina/farmacologia , Modelos Animais de Doenças , Diterpenos/farmacologia , Resistência a Medicamentos/efeitos dos fármacos , Resistência a Medicamentos/fisiologia , Locus Cerúleo/efeitos dos fármacos , Locus Cerúleo/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos ICR , Neurônios Aferentes/fisiologia , Neurotoxinas/farmacologia , Nociceptores/fisiologia , Norepinefrina/biossíntese , Dor/fisiopatologia , Medição da Dor/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-fos/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-fos/metabolismo , Receptores Adrenérgicos alfa 2/efeitos dos fármacos , Receptores Adrenérgicos alfa 2/metabolismo , Medula Espinal/efeitos dos fármacos , Medula Espinal/metabolismo , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
Several lines of evidence indicate significant interactions between the immune and nervous systems. Our recent study reveals that 'bee venom (BV) induced anti-inflammatory effect' (BVAI) was produced by sympathetic preganglionic neuronal activation and subsequent adrenomedullary catecholamine release in a zymosan-induced inflammation model. However, the specific peripheral input and the supraspinal neuronal systems that are involved in this BVAI remain to be defined. Here we show that subcutaneous BV injection into left hind limb significantly reduces zymosan-induced leukocyte migration and that this effect is completely inhibited by denervation of the left sciatic nerve. This BVAI was not affected by the destruction of capsaicin-sensitive primary afferent fibers using either neonatal capsaicin or resiniferatoxin (RTX) pretreatment. BV injection into the left hind limb significantly increased Fos expression in the contralateral locus coeruleus (LC) in non-inflamed mice. In zymosan-inflamed mice, BV injection produced a further increase in LC Fos expression as compared with non-inflamed mice. This BV-induced Fos increase in the LC was not affected by RTX pretreatment. Pharmacological blockage of central noradrenergic activity by either central chemical sympathectomy (i.c.v. 6-hydroxydopamine) or alpha2 adrenoceptor antagonism (i.c.v. idazoxan) completely blocked BVAI. Taken together, these results suggest that BVAI is mediated by peripheral activation of capsaicin-insensitive primary afferent fibers and subsequent central noradrenergic activation including the LC.
Assuntos
Anti-Inflamatórios/uso terapêutico , Venenos de Abelha/uso terapêutico , Inflamação/tratamento farmacológico , Locus Cerúleo/efeitos dos fármacos , Norepinefrina/metabolismo , Adrenérgicos/farmacologia , Animais , Capsaicina/farmacologia , Modelos Animais de Doenças , Diterpenos/farmacologia , Interações Medicamentosas , Lateralidade Funcional , Expressão Gênica/efeitos dos fármacos , Inflamação/induzido quimicamente , Leucócitos/efeitos dos fármacos , Leucócitos/fisiologia , Locus Cerúleo/metabolismo , Camundongos , Camundongos Endogâmicos ICR , Proteínas Oncogênicas v-fos/metabolismo , Oxidopamina/farmacologia , Neuropatia Ciática/dietoterapia , Neuropatia Ciática/patologia , Neuropatia Ciática/fisiopatologia , ZimosanRESUMO
BACKGROUND: Although acupuncture has been widely used for complementary therapeutic approaches to treat inflammatory diseases and inflammation-induced pain, the potential anti-inflammatory effects of acupuncture treatment remain controversial in clinical trials, and the underlying mechanisms are still unclear. OBJECTIVE: The objective was to determine whether electroacupuncture (EA) is able to suppress the peripheral inflammatory response (e.g., zymosan-induced leukocyte migration into air pouch). As part of a mechanistic approach, it was further evaluated whether endogenous opioid systems are involved in the "EA-induced anti-inflammatory effect" (EA-AI). METHODS: EA (1 or 120 Hz) was performed bilaterally in the Zusanli acupoint (ST36) or in a nonacupoint (gluteal muscle) for 30 min in ICR mice under anesthetic condition. The number of leukocytes that migrated into the air pouch was counted 4 hours after zymosan injection. EA was performed at 0, 0.5, 1, or 2 hours prior to zymosan injection, respectively. To evaluate opioid involvement in EA-AI, intrathecal naloxone (36 microg/mouse) and intraperitoneal naloxone methiodide (30 mg/kg) were administered 10 min before EA stimulation. RESULTS: Both the 1 and 120 Hz frequencies of EA into Zusanli acupoint at the same time with zymosan injection significantly reduced leukocyte migration into the air pouch as compared with those of control groups (i.e., anesthetic control and needling control into Zusanli acupoint without electrical stimulation). The EA stimulation into nonacupoint did not produce any significant anti-inflammatory effect. EA treatment at 0.5 hours prior to zymosan injection also produced an anti-inflammatory effect but 1 and 2 hours prior to zymosan injection did not elicit any effect. Peripheral opioid blockage significantly reversed EA-AI, whereas spinal opioid blockage did not alter EA-AI. CONCLUSION: EA can suppress peripheral inflammation through a peripheral opioid mechanism. To achieve the full effectiveness of EA, repeated application is recommended for the treatment of a variety of inflammatory diseases.
Assuntos
Eletroacupuntura/métodos , Inflamação/terapia , Dor/prevenção & controle , Receptores Opioides/efeitos da radiação , Análise de Variância , Animais , Regulação para Baixo , Edema/induzido quimicamente , Inflamação/induzido quimicamente , Masculino , Camundongos , Camundongos Endogâmicos ICR , Dor/etiologia , Receptores Opioides/metabolismo , Zimosan/toxicidadeRESUMO
We have previously shown that subcutaneous bee venom (BV) injection reduces visceral pain behavior in mice, but it is not clear which constituent of BV is responsible for its antinociceptive effect. In the present study, we now demonstrate that a water-soluble subfraction of BV (BVA) reproduces the antinociceptive effect of BV in acetic acid-induced visceral pain model. We further evaluated three different BVA subfractions that were separated by molecular weight, and found that only the BVAF3 subfraction (a molecular weight of <10 kDa) produced a significant antinociceptive effect on abdominal stretches and suppressed visceral pain-induced spinal cord Fos expression. Injection of melittin (MEL), a major constituent of BVAF3, also produced a visceral antinociception. However, melittin's antinociception was completely blocked by boiling for 10 min at 100 degrees C, while boiling either whole BV or BVAF3 did not prevent their antinociception. The antinociceptive effect of BVAF3 was completely blocked by intrathecal pretreatment with the alpha2-adrenoceptor antagonist, yohimbine (YOH), while intrathecal pretreatment with the opioid antagonist, naloxone (NAL) or the serotonin antagonist, methysergide, had no effect. These data demonstrate that BVAF3 is responsible for the visceral antinociception of whole BV and further suggest that this effect is mediated in part by spinal alpha2-adrenergic activity.
Assuntos
Venenos de Abelha/uso terapêutico , Dor/tratamento farmacológico , Receptores Adrenérgicos alfa 2/metabolismo , Medula Espinal/efeitos dos fármacos , Animais , Venenos de Abelha/isolamento & purificação , Venenos de Abelha/farmacologia , Abelhas , Fracionamento Químico , Masculino , Camundongos , Camundongos Endogâmicos ICR , Peso Molecular , Dor/metabolismo , Solubilidade , Medula Espinal/metabolismo , Vísceras/efeitos dos fármacos , Vísceras/fisiologia , ÁguaRESUMO
UNLABELLED: Chemical acupuncture with diluted bee venom (DBV), termed apipuncture, has been traditionally used in oriental medicine to treat several inflammatory diseases and chronic pain conditions. In the present study we investigated the potential antihyperalgesic and antiallodynic effects of apipuncture in a rat neuropathic pain model. DBV (0.25 mg/kg, subcutaneous) was injected into the Zusanli acupoint 2 weeks after chronic constrictive injury (CCI) of the sciatic nerve. Between 5 and 45 minutes after DBV injection, we observed a significant reduction in the thermal hyperalgesia induced by CCI, but apipuncture failed to reduce CCI-induced mechanical allodynia. We subsequently examined whether this antihyperalgesic effect of apipuncture was related to the activation of spinal opioid receptors and/or alpha2-adrenoceptors. Intrathecal pretreatment with naloxone (10 microg/rat), an opioid receptor antagonist, did not reverse the antihyperalgesic effect of apipuncture, whereas pretreatment with idazoxan (40 microg/rat), an alpha2-adrenoceptor antagonist, completely blocked the effect of apipuncture. These results indicate that DBV-induced apipuncture significantly reduces the thermal hyperalgesia generated by CCI and also suggest that this antihyperalgesic effect is dependent on the activation of alpha2-adrenoceptors, but not opioid receptors, in the spinal cord. PERSPECTIVE: The antinociceptive effect of apipuncture was evaluated in a rodent neuropathic pain model. The relieving effect of apipuncture on thermal hyperalgesia was found to be mediated by spinal alpha2-adrenoceptors, but not opioid receptors. These data suggest that apipuncture might be an effective alternative therapy for patients with painful peripheral neuropathy, especially for those who are poorly responsive to opioid analgesics.
Assuntos
Pontos de Acupuntura , Venenos de Abelha/administração & dosagem , Hiperalgesia/terapia , Manejo da Dor , Receptores Adrenérgicos alfa 2/fisiologia , Antagonistas Adrenérgicos/farmacologia , Antagonistas de Receptores Adrenérgicos alfa 2 , Animais , Modelos Animais de Doenças , Masculino , Ratos , Ratos Sprague-Dawley , Medula Espinal/metabolismoRESUMO
In two previous reports, we have demonstrated that injection of bee venom (BV) into an acupoint produces a significant antinociceptive and anti-inflammatory effect in both a mouse model of visceral nociception and a rat model of chronic arthritis. The present study was designed to evaluate the potential antinociceptive effect of BV pretreatment on formalin-induced pain behavior and it associated spinal cord Fos expression in rats. Adult Sprague-Dawley rats were injected with BV directly into the Zusanli (ST36) acupoint or into an arbitrary non-acupoint located on the back. BV pretreatment into the Zusanli acupoint significantly decreased paw-licking time in the late phase of the formalin test. In contrast, BV injected into a non-acupoint in the back region did not suppress the paw-licking time. In addition, BV pretreatment into the Zusanli acupoint markedly inhibited spinal cord Fos expression induced by formalin injection. These findings indicate that BV pretreatment into the Zusanli acupoint has an antinociceptive effect on formalin-induced pain behavior.
Assuntos
Pontos de Acupuntura , Venenos de Abelha/farmacologia , Formaldeído/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Manejo da Dor , Dor/tratamento farmacológico , Proteínas Proto-Oncogênicas c-fos/metabolismo , Medula Espinal/metabolismo , Animais , Relação Dose-Resposta a Droga , Masculino , Dor/induzido quimicamente , Ratos , Ratos Sprague-DawleyRESUMO
In this study, we aimed to determine the antinociceptive and/or anti-inflammatory effect of Bang-Poong (BP, Radix Ledebouriellae) on Freund's adjuvant-induced arthritis in rats. Traditionally, BP has been used to treat several inflammatory diseases such as arthritis. Whole BP is extracted into two fractions that were ethylacetate and hexane-soluble fractions. Adult Sprague-Dawley rats (n=30, 130-150 g) were subcutaneously administered by the Freund's complete adjuvant (FCA) into the plantar surface of right hindpaw. Twelve days after the injection of FCA, the rats initially showed typical inflammatory edema and arthritis-related symptoms on the contralateral side (i.e. left hindpaw). Both antinociceptive (evaluation of mechanical, thermal pain threshold and analysis of spinal Fos expression) and anti- inflammatory (evaluation of paw edema, serum interleukin-6 level and x-ray analysis) effect of BP extracts were examined. The ethylacetate fraction of BP (BPE) significantly suppressed the FCA-induced paw edema as well as the serum level of interleukin-6 and it alleviated the radiological changes. Moreover, both mechanical and thermal hyperalgesia were attenuated by the treatment of BPE. In addition, spinal Fos expression that was increased by FCA- injection was suppressed in BPE group. Therefore, this study showed that BPE produced significant both antinociceptive and anti-inflammatory effects on FCA- induced arthritis in rats, while hexane fraction of BP did not show these effects. In conclusion, it is suggested that the ethylacetate fraction of BP is recommended to alleviate the arthritis-related symptoms in human according to the results of this study.