Effect Of Neurotropin Research Articles

Neurotropin alleviates cognitive impairment by inhibiting TLR4/MyD88/NF-κB inflammation signaling pathway in mice with vascular dementia

Vascular dementia (VD) is the second most common cause of dementia after Alzheimer's disease. Neuroinflammation contributes to pathogenesis of VD. Neurotropin (NTP) is an analgesic that has been shown to suppress inflammation and neural repair. But its effects on VD are still unclear. Therefore, this study aimed to investigate the therapeutic effects and potential mechanisms of NTP in the VD model mice established by bilateral common carotid artery stenosis method. In VD mice, we found that NTP treatment increased cerebral blood flow by Laser speckle imaging, reduced neuron loss by Nissl, HE and immunochemistry staining, attenuated white matter damage by magnetic resonance imaging and ultrastructural damage by transmission electron microscope, improved cognitive functions by new object recognition test and three-chamber test, Y maze test and Morris water maze test, inhibited significantly glial activation by immunofluorescence methods, reduced the expression of TLR4, down-regulated expression of MyD88 and phosphorylation of NF-κB P65, decreased the levels of pro-inflammatory cytokines IL-1β, IL-6 and TNFα. Further, we showed that administration of a TLR4 inhibitor TAK242 had a similar effect to NTP, while the TLR4 agonist CRX-527 attenuated the effect of NTP in the VD mice. Collectively, our study suggested that NTP alleviates cognitive impairment by inhibiting TLR4/MyD88/NF-κB inflammation signaling pathway in the VD mice. Thus, NTP may be a promising therapeutic approach and a potential TLR4 inhibitor for VD.

Neurotropin® accelerates peripheral nerve regeneration in a rat sciatic nerve crush injury model

BackgroundPeripheral nerve injuries are common and serious conditions. The effect of Neurotropin® (NTP), a nonprotein extract derived from the inflamed skin of rabbits inoculated with vaccinia virus, on peripheral nerve regeneration has not been fully elucidated. However, it has analgesic properties via the activation of descending pain inhibitory systems. Therefore, the current study aimed to determine the effects of NTP on peripheral nerve regeneration. MethodsWe examined axonal outgrowth of dorsal root ganglion (DRG) neurons using immunocytochemistry in vitro. In addition, nerve regeneration was evaluated functionally, electrophysiologically, and histologically in a rat sciatic nerve crush injury model in vivo. Furthermore, gene expression of neurotrophic factors in the injured sciatic nerves and DRGs was evaluated. ResultsIn the dorsal root ganglion neurons in vitro, NTP promoted axonal outgrowth at a concentration of 10 mNU/mL. Moreover, the systemic administration of NTP contributed to the recovery of motor and sensory function at 2 weeks, and of sensory function, nerve conduction velocity, terminal latency, and axon-remyelination 4 weeks after sciatic nerve injury. In the gene expression assessment, insulin-like growth factor 1 and vascular endothelial growth factor expressions were increased in the injured sciatic nerve 2 days postoperatively. ConclusionsTherefore, NTP might be effective in not only treating chronic pain but also promoting peripheral nerve regeneration after injury.

Effect of neurotropin on Alzheimer's disease-like changes and cognitive function in rats with chronic cerebral hypoperfusion.

Chronic cerebral hypoperfusion (CCH) is a main mechanism of cerebrovascular disease and is associated with various cerebrovascular and neurodegenerative diseases, including Alzheimer's disease. However, treatment of CCH in clinical practice is not ideal, but neurotropin (NTP) has been shown to have a neuroprotective effect. Therefore, this study examined the effect and possible mechanism of NTP in nerve injury caused by CCH. A rat CCH model was established by bilateral common carotid artery occlusion (2VO), and rats were treated with intragastric administration of NTP (200 nu/kg/day) for 28 consecutive days. After treatment, rats were subjected to the Morris water maze and novel object recognition test. Subsequently, an ELISA was applied to detect amyloid-β (Aβ) 1-40 and Aβ1-42 levels in rat hippocampal tissues, quantitative reverse transcription PCR assays were used to detect the mRNA expression levels of brain-derived neurotrophic factor (BDNF) and Trk B, and Western blots were used to detect the protein expression levels of BACE1, tau, p-tau, and protein kinase B (Akt)/glycogen synthase kinase 3β (GSK3β) pathway-related proteins. The rat model of CCH was successfully established by 2VO. Behavioral tests indicated that the cognitive ability of 2VO rats was severely impaired. NTP treatment greatly ameliorated the cognitive disability, reduced Aβ1-40 and Aβ1-42 levels and tau phosphorylation, and upregulated BACE1, Trk B, and BDNF expression in the hippocampus of 2VO rats. Finally, we found that NTP markedly activated Akt/GSK3β pathway activity. NTP can ameliorate cognitive disability in CCH rats possibly by reducing Aβ accumulation and tau phosphorylation in the hippocampus. These effects of NTP may be related to the Akt/GSK3β pathway activation. NTP may be a promising new drug candidate for CCH patients.

Neurotropin protects rotator cuff tendon cells from lidocaine-induced cell death.

BackgroundLocal anesthetics often are used in rotator cuff tears as therapeutic tools, although some cases have reported that they have detrimental effects. Neurotropin (NTP) is used widely in Japan as a treatment for various chronic pain conditions and is shown to have protective effects on cartilage and nerve cells. In this study, we investigated the protective effect of NTP against lidocaine-induced cytotoxicity.MethodsTenocytes from rotator cuff tendons were incubated with lidocaine, NTP, lidocaine with NTP, and a control medium. Cell viability was evaluated using the WST-8 assay. Cell apoptosis was detected via annexin V staining using flow cytometry. The expression of BCL-2 and cytochrome c, which are involved in the intrinsic mitochondrial pathway of apoptosis, was evaluated via Western blotting and immunohistochemical staining.ResultsIn the cell viability assay, lidocaine decreased cell viability in a dose-dependent manner, and NTP did not affect cell viability. Moreover, NTP significantly inhibited the cytotoxic effect of lidocaine. The flow cytometry analysis showed that lidocaine significantly induced apoptosis in tenocytes, and NTP considerably inhibited this lidocaine-induced apoptosis. Western blotting experiments showed that lidocaine decreased the protein expression of BCL-2, and that NTP conserved the expression of BCL-2, even when used with lidocaine. Immunohistochemical staining for cytochrome c showed that 0.1% lidocaine increased cytochrome c-positive cells, and NTP suppressed lidocaine-induced cytochrome c expression.ConclusionsNTP suppresses lidocaine-induced apoptosis of tenocytes by inhibiting the mitochondrial apoptotic pathway. Intra-articular/ bursal injection of NTP with lidocaine could protect tenocytes in rotator cuff tendons against lidocaine-induced apoptosis.

Neurotropin Inhibits Lipid Accumulation by Maintaining Mitochondrial Function in Hepatocytes via AMPK Activation.

The accumulation of lipid droplets in the cytoplasm of hepatocytes, known as hepatic steatosis, is a hallmark of non-alcoholic fatty liver disease (NAFLD). Inhibiting hepatic steatosis is suggested to be a therapeutic strategy for NAFLD. The present study investigated the actions of Neurotropin (NTP), a drug used for chronic pain in Japan and China, on lipid accumulation in hepatocytes as a possible treatment for NAFLD. NTP inhibited lipid accumulation induced by palmitate and linoleate, the two major hepatotoxic free fatty acids found in NAFLD livers. An RNA sequencing analysis revealed that NTP altered the expression of mitochondrial genes. NTP ameliorated palmitate-and linoleate-induced mitochondrial dysfunction by reversing mitochondrial membrane potential, respiration, and β-oxidation, suppressing mitochondrial oxidative stress, and enhancing mitochondrial turnover. Moreover, NTP increased the phosphorylation of AMPK, a critical factor in the regulation of mitochondrial function, and induced PGC-1β expression. Inhibition of AMPK activity and PGC-1β expression diminished the anti-steatotic effect of NTP in hepatocytes. JNK inhibition could also be associated with NTP-mediated inhibition of lipid accumulation, but we did not find the association between AMPK and JNK. These results suggest that NTP inhibits lipid accumulation by maintaining mitochondrial function in hepatocytes via AMPK activation, or by inhibiting JNK.

Neurotropin inhibits neuronal activity through potentiation of sustained Kv currents in primary cultured DRG neurons

Neurotropin (NTP) is a Japanese analgesic agent for treating neuropathic pain; however, its method of action remains unclear. This study examined the effects of NTP on the activity of small dorsal root ganglion (DRG) neurons using whole-cell patch clamp recordings. After 3 days of treatment, NTP decreased current injection-induced firing activity of cultured DRG neurons by raising the current threshold for action potential generation. Additionally, NTP increased the sustained component of voltage-gated potassium (Kv) channel currents without affecting other K+ currents. These results suggest that NTP inhibits the firing activity of DRG neurons through augmentation of sustained Kv current.

Neurotropin inhibits neuroinflammation via suppressing NF-κB and MAPKs signaling pathways in lipopolysaccharide-stimulated BV2 cells

Neurotropin (NTP) is a widely used drug in China and Japan mainly for the treatment of chronic pain and peripheral inflammation. Nevertheless, the effects of NTP on neuroinflammation have not been explored. In this study, we investigated the anti-inflammatory effects of NTP in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells and its underlying mechanisms. BV-2 cells were pretreated with NTP for 12 h before exposure to LPS. The expression of pro-inflammatory cytokines (TNF-α and IL-6) were detected by RT-PCR and EILSA at mRNA and protein levels, respectively. Western blotting was conducted to measure the protein levels of major genes in MAPKs and NF-κB signaling pathways. Results demonstrated that NTP could attenuate the production of pro-inflammatory cytokines. Furthermore, NTP inhibited the activation of NF-κB signaling by decreasing the translocation of NF-κB p65 to the nucleus and suppressed the MAPKs signaling pathway via inhibition of the phosphorylation of p38, ERK and JNK. Taken together, these findings suggest that neurotropin exerts anti-inflammatory effects by suppressing the production of pro-inflammatory mediators via inhibition of NF-κB and MAPKs signaling pathways in LPS-stimulated BV-2 cells.

Effect of Neurotropin on Peripheral Nerve Regeneration

Effect of Neurotropin on Peripheral Nerve Regeneration

Testing Methods for Vegetative Syndrome in the Rat and Effects of Neurotropin and Other Drugs

Testing Methods for Vegetative Syndrome in the Rat and Effects of Neurotropin and Other Drugs

Assessment of Neuroprotective Effects of Neurotropin in Cultured Rat Dorsal Root Ganglion Neurons Using High- Throughput Imaging

Background: Neurotropin, a non-protein extract derived from inflamed rabbit skin following inoculation with vaccinia virus, is an analgesic agent. The mechanism of action of neurotropin has been partially clarified. No experimental study, however, has been undertaken to assess oxaliplatin-induced neurotoxicity using quantitative in vitro high-throughput image analysis. In the present study, to elucidate the action of neurotropin on dorsal root ganglion (DRG) neurons, we explored the antioxidative and anti-inflammatory activity of neurotropin. We assessed the viability and morphological changes in cultured rat DRG neurons treated with oxaliplatin and neurotropin. Methods: We plated dissociated DRG neurons from female Sprague-Dawley rats (100-120 g) into 96-well plates and added oxaliplatin and/or neurotropin. The cells were examined with a fluorescence microscope, ImageXpress. The images were analyzed with high content image processing software, MetaXpress. Cells treated with neurotropin and oxaliplatin were lysed in Pierce RIPA Buffer and subjected to western blot analysis. Results: Significant increases in neurite length, neurite area, cell body area, and neurite branching were observed in the presence of neurotropin in DRG neurons treated with oxaliplatin. When the highest concentration of neurotropin, 40 neurotropin units (NU) mNU/mL, was applied, a marked effect was seen. Neurotropin did not affect the phosphorylation of c-Jun N-terminal kinase, but suppressed the phosphorylation of p38. This finding suggests that neurotropin reversed oxaliplatin-induced apoptosis via suppression of the p38 mitogenactivated protein kinase signaling pathway. Conclusion: The results of this in vitro study suggest a possible role for neurotropin as a useful neuroprotective and anti-apoptotic agent.

Neurotropin(®) ameliorates chronic pain via induction of brain-derived neurotrophic factor.

Neurotropin (NTP)(®), a non-protein extract isolated from the inflamed skin of rabbits inoculated with vaccinia virus, is used clinically for the treatment of neuropathic pain. Moreover, NTP may activate the descending pain inhibitory system. Depression-like behavior is often complicated by chronic pain. However, little is known about NTP-mediated prevention of mood disorders in chronic pain and its molecular mechanisms. We aimed to investigate the effects of NTP on brain-derived neurotrophic factor (BDNF)-mediated signaling and gene expression in chronic pain. In addition, these effects of NTP were compared with pregabalin which is an anticonvulsant, anxiolytic analgesic used to treat neuropathic pain and fibromyalgia. A chronic constriction injury model was established in Sprague-Dawley rats. The pain response was assessed using a paw withdrawal latency (PWL) test and depression was assessed by the immobility time in a forced swim test (FST). NTP was orally administered in two doses of 50 NU (Neurotropin Unit) and 100 NU/kg for 7 days from day 7 after injury. To measure the analgesic and anti-depressant effects of NTP, either K252a (a tyrosine kinase inhibitor), or 5,7-dihydroxy tryptamine (5,7-DHT, a selective toxin for 5-HTergic neurons) was administered by intracerebroventricular injection. Changes in pERK1/2 and pCREB (immunohistochemistry), 5-HT, and BDNF protein level (ELISA) and BDNF mRNA (RT-PCR) were measured in the anterior cingulate cortex (ACC) and in the rostral ventromedial medulla (RVM) 14 days after injury. After injury, the rats showed a decrease in PWL associated with the increase in time of immobility in FST. In this injury model, NTP blocked both the decrease in PWL and the increase in the FST, while pregabalin (10 mg/kg, po.) did not affect the increase in the FST. These effects of NTP were reversed by K252a, and 5,7-DHT. The analgesic effects of pregabalin were not reversed by K252a. NTP normalized the injury-induced excessive activation of pERK1/2 associated with decreased pCREB and BDNF mRNA in the ACC and in the RVM, and these changes were reversed by 5,7-DHT. In contrast, pregabalin did not affect either pCREB or BDNF levels in the chronic pain model. NTP ameliorated chronic pain and pain-related depression by normalizing the induction of BDNF associated with the 5-HTergic system. Pregabalin showed the analgesic effects but had no effects on either depression or the BDNF pathway. These results suggest that NTP may represent an additional drug strategy for chronic pain associated with depression.

Observation on the curative effect of neurotropin combined with etoricoxib in the treatment of pain in patients with ankylosing spondylitis

Objective To discuss the curative effect of neurotropin combined with etoricoxib in the treatment of pain in patients with ankylosing spondylitis (AS).Methods 30 AS patients were randomly divided into two groups.The control group was treated with 7.2Nu neurotropin injection for two weeks.The observation group was given neurotropin injection and 60mg etoricoxib tablets oral per day for two weeks.The Bath AS activity index(BASDAI),Bath AS functional index (BASFI),rachiodynia,hypnalgia and morning stiffness were observed.Results The total effective rate of observation group was superior to the control group,the difference was significant (P ＜ 0.05).No severe adverse reaction was observed.Conclusion Neurotropin combined with etoricoxib has definite effect on AS. Key words: Neurotropin; Etoricoxib; Ankylosing spondylitis ; Pain

Effect of Neurotropin on Chronic Headaches in Children

Effect of Neurotropin on Chronic Headaches in Children

Neurotropin inhibits both capsaicin-induced substance P release and nerve growth factor-induced neurite outgrowth in cultured rat dorsal root ganglion neurones

Neurotropin (NTP), a biological extract from rabbit skin inoculated with vaccinia virus, is an effective analgesic and anti-allergic agent, and has antipruritic effects in various dermatoses including eczema, dermatitis and urticaria. In patients receiving haemodialysis who have pruritus, NTP appears to exert its antipruritic effect by lowering the plasma levels of substance P (SP), but its underlying mechanisms are not fully understood. To investigate the antipruritic mechanisms of NTP. The effects of NTP on capsaicin-induced SP release from neonatal rat dorsal root ganglion (DRG) neurones were assessed by measuring SP concentrations in culture media by a competitive ELISA. The effects of NTP on nerve growth factor (NGF)-induced neurite outgrowth were assessed by measuring the length of the longest process of cultured DRG neurones. The neuronal cytotoxicity of NTP was determined using a methylthiazole tetrazolium cytotoxicity assay. NTP dose-dependently inhibited capsaicin-induced release of SP from cultured DRG neurones, whereas NTP alone had no effect on SP release. Moreover, NTP dose-dependently inhibited NGF-induced neurite outgrowth in cultured DRG neurones. NTP had no observable cytotoxicity. These results suggest that NTP exerts its antipruritic effects by inhibiting both SP release and neurite outgrowth of cutaneous sensory nerves.

Effect of a nonprotein bioactive agent on the reduction of cyclooxygenase-2 and tumor necrosis factor–α in human intervertebral disc cells in vitro

Neurotropin is a nonprotein extract from the inflamed skin of rabbits inoculated with vaccinia virus. In the present study the authors sought to clarify the focal antiinflammatory effects of Neurotropin in intervertebral disc cells, and these effects were compared with those induced by the selective cyclooxygenase (COX)-2 inhibitor 6-methoxy-2-naphthylacetic acid (nabumetone). Six human intervertebral disc specimens were harvested during spinal surgery for lumbar disc herniation. Cells were stimulated with 500 pg/ml of interleukin (IL)-1beta in the presence of various concentrations of Neurotropin (0, 10(-5), 10(-4), and 10(-3) Neurotropin Units/ml) or 50 microg/ml of nabumetone for 3 hours. The mRNA was extracted for polymerase chain reaction (PCR), and real-time PCR was used to quantify the mRNA levels of COX- 2, tumor necrosis factor (TNF)-alpha, and phospholipase A2. Cyclooxygenase-2, TNFalpha, and prostaglandin E2 (PGE2) protein concentrations were each determined by enzyme-linked immunosorbent assay. Neurotropin was found to significantly suppress the expression of COX-2 and TNFalpha at mRNA levels as well as the concentration of COX-2 at protein levels in a dose-dependent manner. Nabumetone was found to significantly increase COX-2 at mRNA levels but directly suppress the concentration of PGE2 in culture medium. Results in this study suggest that Neurotropin has an analgesic effect through the suppression of COX-2 and TNFalpha in a focal area, and nabumetone shows this same effect through the suppression of PGE2 production. Thus, Neurotropin could decrease pain by blocking the central pain pathway or increasing focal antiinflammatory effects.

The Combined Analgesic Effects of Neurotropin and Amitriptyline in SART-stressed Mice

The Combined Analgesic Effects of Neurotropin and Amitriptyline in SART-stressed Mice

Effects of neurotropin on hyperalgesia and allodynia in mononeuropathic rats

Neurotropin is commonly used in Japan for the treatment of chronic pain. Using a rat model, we evaluated the effect of neurotropin on a unilateral peripheral mononeuropathy produced by placing loose ligatures around the sciatic nerve. The effect of neurotropin upon the resultant hyperalgesia and mechanical allodynia was assessed using the Ugo Basile Plantar test and von Frey hairs test, respectively. Neurotropin reduced thermal hyperalgesia and produced an early recovery from hyperalgesia in a dose-dependent manner. No significant reduction in mechanical allodynia, however, was noted under the tested condition. A possibility of differential drug sensitivity for thermal hyperalgesia and mechanical allodynia was indicated in this model, although the reason still remain elusive.

Effect of neurotropin on regional cerebral blood flow and systemic blood pressure

Experiments on rabbits show that neurotropin has no effect on regional cerebral flow and systemic blood pressure under normal conditions, but reduces regional cerebral flow in partial circulatory hypoxia (ischemia) and recirculation.

Effects of neurotropin on pain syndromes of various etiology

Abstract The effects of neurotropin have been studied on a model of a neuropathic pain syndrome caused by sciatic nerve injury as well as on a model of the adjuvant arthritis pain syndrome caused by Freund's adjuvant injected into the plantar region of the lower limb. The experimental results suggest that neurotropin prevents the development of the neuropathic pain syndrome in many cases and relieves the pathological process in the already developed syndrome. However, neurotropin fails to prevent the development of adjuvant arthritis but markedly decreases its severity. Neurotropin normalized the thresholds of pain sensitivity upon thermal stimulation (`hot plate' method) which remain at a sufficiently high level also after cessation of neurotropin injections. The analgetic action of neurotropin is due to its suppressive effect on various links of the pathologic algic system.

Neurotropin inhibits accumulation of eosinophils induced by allergen through the suppression of sensitized T-cells

A non-protein extract isolated from the inflamed dermis of rabbits inoculated with vaccinia virus (Neurotropin®) has been clinically used in Japan as an analgesic and anti-allergic drug. To clarify its anti-allergic mechanism, the effect of Neurotropin on eosinophil accumulation induced by ragweed pollen extract or plateletactivating factor (PAF) was examined in BALB/c mice. Neurotropin inhibited the T-cell-dependent accumulation of eosinophils induced by allergen in a dose-dependent manner when administered during sensitization. However, Neurotropin was unable to inhibit the T-cell-independent accumulation of eosinophils induced by PAF. A T-cell transfer experiment was performed to address the inhibitory mechanism. A marked accumulation of eosinophils was observed when recipients were injected i.p. with allergen and Nylon wool column-passed splenic T-cells from the sensitized donor mice. However, significant accumulation of eosinophils was not observed when sensitized donor mice were administered with Neurotropin but not saline. Taken together, these results suggest that Neurotropin inhibits the accumulation of eosinophils induced by allergen via the suppression of sensitized T-cell induction, or alternatively by interfering with T-cell function.