Evaluation of Stem Cell Laden Collagen + Polycaprolactone + Multi-Walled Carbon Nano-Tubes Nano-Neural Scaffold with and Without Insulin Like Growth Factor-I For Sciatic Nerve Regeneration Post Crush Injury in Wistar Rats.

BACKGROUND/AIMS: All body functions are activated, synchronized and controlled by a substantial, complex network, the nervous system. Upon injury, pathophysiology of the nerve injury proceeds through different paths. The axon may undergo a degenerative retraction from the site of injury for a short distance unless the injury is near to the cell body, in which case it continues to the soma and undergoes retrograde neuronal degeneration. Otherwise, the distal section suffers from Wallerian degeneration, which is marked by axonal swelling, spheroids, and cytoskeleton degeneration. The objective of the study was to evaluate the potential of mesenchymal stem cell laden neural scaffold and insulin-like growth factor I (IGF-I) in nerve regeneration following sciatic nerve injury in a rat model. METHODS: The animals were anaesthetized and a cranio-lateral incision over left thigh was made. Sciatic nerve was exposed and crush injury was introduced for 90 seconds using haemostat at second locking position. The muscle and skin were sutured in routine fashion and thus the rat model of sciatic crush injury was prepared. The animal models were equally distributed into 5 different groups namely A, B, C, D and E and treated with phosphate buffer saline (PBS), carbon nanotubes based neural scaffold only, scaffold with IGF-I, stem cell laden scaffold and stem cell laden scaffold with IGF-I respectively. In vitro scaffold testing was performed. The nerve regeneration was assessed based on physico-neuronal, biochemical, histopathological examination, and relative expression of NRP-1, NRP-2 and GAP-43 and scanning electron microscopy. RESULTS: Sciatic nerve injury model with crush injury produced for 90 seconds was standardized and successfully used in this study. All the biochemical parameters were in normal range in all the groups indicating no scaffold related changes. Physico-neuronal, histopathological, relative gene expression and scanning electron microscopy observations revealed appreciable nerve regeneration in groups E and D, followed by C and B. Restricted to no regeneration was observed in group A. CONCLUSION: Carbon nanotubes based scaffold provided electro-conductivity for proper neuronal regeneration while rat bone marrow-derived mesenchymal stem cells were found to induce axonal sprouting, cellular transformation; whereas IGF-I induced stem cell differentiation, myelin synthesis, angiogenesis and muscle differentiation.

The effects of curcumin and blueberry on axonal regeneration after peripheral nerve injury.

The purpose of this study was to analyze the axonal regeneration and therapeutic effects of curcumin and blueberry administration following peripheral nerve injury using stereological, electron microscopic and electrophysiological methods. Animals in were assigned into one of four groups - control (Cont), injury (Inj), injury+curcumin (Cur) and injury+blueberry (Blue). Following the induction of sciatic nerve crush injury (75 Newtons for 5 s) in the Inj, Cur, and Blue groups, the rats in the Cur group received intraperitoneal injection of 30 mg/kg curcumin (Sigma C1386) and the rats in the Blue group received 4 g/kg blueberry by gavage over a four-week period. The rats in the Cont and Inj groups were not exposed to any substance. All animals were given standard chow. Sciatic functional index analyses were performed on the 14th and 28th days after injury, and electromyography (EMG) results were recorded. Stereological analysis of the nerve was performed under light microscopy. Light and electron microscopies were used for the histopathological evaluation of the sciatic nerve. Analysis of myelinated axon numbers revealed no significant differences between the Inj group and the Cur and Blue groups. However, a significant difference was observed between the Blue and Inj groups in terms of axonal areas. EMG test results differed between the Blue and the Inj groups (p < 0.05), but no significant difference was observed between the Inj and Cur groups. Electron microscopic analysis revealed protective effects of curcumin and blueberry treatment after injury. The use of the curcumin and blueberry may represent a supportive approach to the protection of nerve fibers after peripheral nerve crush injury.

Pinostrobin from Boesenbergia rotunda attenuates oxidative stress and promotes functional recovery in rat model of sciatic nerve crush injury.

Oxidative stress plays a role in the delay of peripheral nerve regeneration after injury. The accumulation of free radicals results in nerve tissue damage and dorsal root ganglion (DRG) neuronal death. Pinostrobin (PB) is one of the bioflavonoids from Boesenbergia rotunda and has been reported to possess antioxidant capacity and numerous pharmacological activities. Therefore, this study aimed to investigate the effects of PB on peripheral nerve regeneration after injury. Male Wistar rats were randomly divided into 5 groups including control, sham, sciatic nerve crush injury (SNC), SNC + 20 mg/kg PB, and SNC + 40 mg/kg PB. Nerve functional recovery was observed every 7 days. At the end of the study, the sciatic nerve and the DRG were collected for histological and biochemical analyses. PB treatment at doses of 20 and 40 mg/kg reduced oxidative stress by up-regulating endogenous glutathione. The reduced oxidative stress in PB-treated rats resulted in increased axon diameters, greater number of DRG neurons, and p-ERK1/2 expression in addition to faster functional recovery within 4 weeks compared to untreated SNC rats. The results indicated that PB diminished the oxidative stress-induced nerve injury. These effects should be considered in the treatment of peripheral nerve injury.

Erythropoietin-PLGA-PEG as a local treatment to promote functional recovery and neurovascular regeneration after peripheral nerve injury.

BACKGROUND: Traumatic peripheral nerve injury (TPNI) is a major medical problem with no universally accepted pharmacologic treatment. We hypothesized that encapsulation of pro-angiogenic erythropoietin (EPO) in amphiphilic PLGA-PEG block copolymers could serve as a local controlled-release drug delivery system to enhance neurovascular regeneration after nerve injury. METHODS: In this study, we synthesized an EPO-PLGA-PEG block copolymer formulation. We characterized its physiochemical and release properties and examined its effects on functional recovery, neural regeneration, and blood vessel formation after sciatic nerve crush injury in mice. RESULTS: EPO-PLGA-PEG underwent solution-to-gel transition within the physiologically relevant temperature window and released stable EPO for up to 18 days. EPO-PLGA-PEG significantly enhanced sciatic function index (SFI), grip strength, and withdrawal reflex post-sciatic nerve crush injury. Furthermore, EPO-PLGA-PEG significantly increased blood vessel density, number of junctions, and myelinated nerve fibers after injury. CONCLUSION: This study provides promising preclinical evidence for using EPO-PLGA-PEG as a local controlled-release treatment to enhance functional outcomes and neurovascular regeneration in TPNI.

Evaluation of the therapeutic effects of calcium dobesilate in sciatic nerve crush injury in rats.

INTRODUCTION: Proinflammatory cytokines released from nerve endings and surrounding injured tissue after nerve damage can prolong the inflammation process, delay nerve healing or result in poor quality nerve healing. In this case, due to the loss of function in the muscles innervated by the damaged nerve, the patient may have neurological and functional difficulties which may reduce the patient's quality of life and create an economic burden. Although the attempts of many pharmacological agents to heal crush injury of peripheral nerves have been recorded in literature, a drug that can provide adequate recovery of the crushed nerve and can be applied in daily life has not been defined as yet. This study aimed to assess the effects of calcium dobesilate on sciatic nerve crush injury in a rat model. METHODS: A total of 26 male Wistar albino rats were separated into four groups as follows: CONTROL group (healthy subjects, n=6); SHAM group (crush injury was created, n=6); MP group (after created crush injury, methylprednisolone was administered, n=7); and CAD group (after created crush injury, calcium dobesilate was administered, n=7). A crush injury was created, then the electrophysiological findings and sciatic nerve functional index (SFI) were recorded before euthanasia. After the euthanasia of all the rats, samples of the crushed nerve and gastrocnemius muscle were evaluated histopathologically, immunohistochemically, and biochemically. RESULTS: Both pharmacological agents were histopathologically effective in axon regeneration and repair. Calcium dobesilate did not preserve total muscle mass but was seen to prevent atrophy microscopically. Immunohistochemistry and biochemistry results showed that calcium dobesilate and methylprednisolone had anti-inflammatory, anti-oxidant, anti-apoptotic, and anti-autophagic activity in the crushed sciatic nerve. Neither calcium dobesilate nor methylprednisolone improved the nerve conductance level. SFI values obtained on day 30 from the CAD group were numerically closer to the values of the healthy animals but not at a statistically significant level. CONCLUSION: The study results demonstrated that calcium dobesilate could suppress inflammatory processes and provide histopathological and functional improvements in the injured nerve in rats. Therefore, further clinical studies are recommended to investigate in detail the therapeutic effects of calcium dobesilate on peripheral nerve crush injury.

Effects of bee honey on promotion of peripheral nerve regeneration in an experimental model of nerve crush injury.

Peripheral nerve injuries are commonly encountered within clinical settings because of accidental trauma. This study aimed to examine the therapeutic effect of bee honey on peripheral nerve crush injury through a histological and physiological perspective. In this study, forty Wistar rats were divided into four groups. Rats were subjected to surgical operations to expose the sciatic nerve. Animals of the first group were operated without inducing any lesion to the nerve. The other three groups were subjected to induction of nerve crush injury. Two groups of them were treated with honey solution locally and intraperitoneally respectively. The other group served as injured nontreated group. Two physiological tests were performed to examine the living animals' nerve functions. At the end of the experimental period, the rats were sacrificed, and samples from the sciatic nerve and gastrocnemius muscle were obtained for histological, immunohistochemical and ultrastructural examination. Physiological indicators and structural investigations demonstrated considerable amelioration of the function and structure of nerves and muscles in the two treated groups compared with the injured nontreated group. The findings indicate that the bee honey has a curative effect on the peripheral nerve crush injury in the rat model.

Altered gut microbiota composition with antibiotic treatment impairs functional recovery after traumatic peripheral nerve crush injury in mice: effects of probiotics with butyrate producing bacteria.

OBJECTIVE: Antibiotics (ABX) are widely used for life-threatening infections and also for routine surgical operations. Compelling evidence suggests that ABX-induced alterations of gut microbiota composition, termed dysbiosis, are linked with diverse disease states including neurological and neurodegenerative conditions. To combat the consequences of dysbiosis, probiotics (PBX) are widely used. ABX-induced dysbiosis is reported to impair neurological function after spinal cord injury. Traumatic peripheral nerve injury (TPNI) results in profound neurologic impairment and permanent disability. It is unknown whether ABX treatment-induced dysbiosis has any impact on TPNI-induced functional recovery, and if so, what role medical-grade PBX could have on TPNI recovery. RESULTS: In this study, ABX-induced dysbiosis and PBX-induced microbiota enrichment models were used to explore the potential role of gut microbiome in TPNI. Stool analysis with 16S ribosomal RNA (rRNA) gene sequencing confirmed ABX-induced dysbiosis and revealed that ABX-induced changes could be partially restored by PBX administration with an abundance of butyrate producing bacteria. Pre-injury ABX significantly impaired, but pre-injury PBX significantly improved post-TPNI functional recovery. Importantly, post-injury PBX protected against pre-injury ABX-induced functional impairment. These findings demonstrate that reestablishment of gut microbiota composition with butyrate producing PBX during ABX-induced dysbiosis could be a useful adjuvant therapy for TPNI.

Potential Effects of Stem Cells Derived from the Peripheral Nerve and Adipose Tissue after the Nerve Crush Injury in Control and Obese Rats.

Aim of this study is to investigate effects of stem cells derived from the peripheral nerve and adipose tissues following the nerve crush injury in control and obese rats. For this aim, 41 Wistar Albino female rats were separated into eight equal groups; non-obese control (NOC) obese control (OC), non-obese injury (NOH), obese injury (OH), non-obese adipose (NOY), obese adipose (OY), non-obese nerve (NOPS), obese nerve (OPS). At the end of 8 weeks, all experimental animals without control groups were subjected to nerve crush procedure and sciatic nerve or fat stem cell homogenates were injected on the treatment group rats, and then, recovery process has been observed and histopathological, stereological, electrophysiological analyses and bioinformatic evaluation were made on removed sciatic nerves. Stereological results showed that adipose homogenate gave more successful results than peripheral nerve homogenates in the NOY group in comparison to the NOPS group in terms of myelinated axon number. Peripheral nerve homogenate has shown more successful results in the OPS group in comparison to the OY group. The number of unmyelinated axons was increased following treatment with adipose tissue homogenate in NOY and OY groups. In terms of myelin sheath thickness; we detected that treatments by peripheral nerve and especially adipose tissue homogenates lead to increase in the thickness of the axons of the peripheral nerves belong to the control and obese injury groups. All results showed that mesenchymal stem cell treatment by fresh tissue homogenates is successful in peripheral nerve regeneration and fat tissue is a considerable source of the stem cells for clinical applications.

Comparing effects of L-carnitine and sildenafil citrate on histopathologic recovery from sciatic nerve crush injury in female albino rats.

BACKGROUND: The sciatic nerve is a peripheral nerve and is more vulnerable to compression with subsequent short- or long-term neuronal dysfunction. The current study was designed to elucidate the possible ameliorative effect of L-carnitine and sildenafil (SIL) on sciatic nerve crush injury. We sought to determine the effects of L-carnitine, a neuroprotective and a neuro-modulatory agent, and SIL citrate, a selective peripheral phosphodiesterases inhibitor, on modulating neuro-degenerative changes due to sciatic nerve compression. MATERIALS AND METHODS: The comparative effect of L-carnitine (at an oral dose of 20 mg/kg/day) or SIL citrate (20 mg/kg/day orally) administration for 21 days was studied in a rat model of sciatic nerve compression. Sciatic nerve sections were subjected to biochemical, histological, ultrastructure, and immunohistochemical studies to observe the effects of these treatments on neurofilament protein. RESULTS: The sciatic nerve crush injury group (group II) showed a significant decrease in tissue catalase (CAT), superoxide dismutase (SOD) and increase in malondialdehyde (MDA) as compared to control group (p < 0.01). Histological changes in the form of degenerated and vacuolated axoplasm with areas of nerve fibre loss and pyknotic nuclei were reported. The blood vessels were dilated, congested with areas of haemorrhage and mononuclear cell infiltration. Histo-morphometrically, a statistically significant reduction in the nerve fibres' number, mean axon cross-sectional area, myelin sheath thickness and a significant increase in collagen fibres' percentage (p < 0.05) as compared to control group. Immunohistochemically, neurofilament protein was significantly downregulated as proved by a significant reduction in mean area per cent of neurofilament expression. L-carnitine ameliorated the studied parameters through its neuroprotective effect while SIL, a selective peripheral phosphodiesterases (PDE-5) inhibitor, improved crush injury parameters but with less extent than L-carnitine. CONCLUSIONS: These findings indicate the valuable effects of L-carnitine administration compared to that of SIL citrate in alleviating the serious debilitating effects of sciatic nerve crush injury. Our results provide a new insight into the scope of neuroprotective and neuro-regenerative effects of L-carnitine in a sciatic nerve compression model.

Peptide ligands targeting FGF receptors promote recovery from dorsal root crush injury via AKT/mTOR signaling.

Background: Fibroblast growth factor receptors (FGFRs) are key targets for nerve regeneration and repair. The therapeutic effect of exogenous recombinant FGFs in vivo is limited due to their high molecular weight. Small peptides with low molecular weight, easy diffusion, low immunogenicity, and nontoxic metabolite formation are potential candidates. The present study aimed to develop a novel low-molecular-weight peptide agonist of FGFR to promote nerve injury repair. Methods: Phage display technology was employed to screen peptide ligands targeting FGFR2. The peptide ligand affinity for FGFRs was detected by isothermal titration calorimetry. Structural biology-based computer virtual analysis was used to characterize the interaction between the peptide ligand and FGFR2. The peptide ligand effect on axon growth, regeneration, and behavioral recovery of sensory neurons was determined in the primary culture of sensory neurons and dorsal root ganglia (DRG) explants in vitro and a rat spinal dorsal root injury (DRI) model in vivo. The peptide ligand binding to other membrane receptors was characterized by surface plasmon resonance (SPR) and liquid chromatography-mass spectrometry (LC-MS)/MS. Intracellular signaling pathways primarily affected by the peptide ligand were characterized by phosphoproteomics, and related pathways were verified using specific inhibitors. Results: We identified a novel FGFR-targeting small peptide, CH02, with seven amino acid residues. CH02 activated FGFR signaling through high-affinity binding with the extracellular segment of FGFRs and also had an affinity for several receptor tyrosine kinase (RTK) family members, including VEGFR2. In sensory neurons cultured in vitro, CH02 maintained the survival of neurons and promoted axon growth. Simultaneously, CH02 robustly enhanced nerve regeneration and sensory-motor behavioral recovery after DRI in rats. CH02-induced activation of FGFR signaling promoted nerve regeneration primarily via AKT and ERK signaling downstream of FGFRs. Activation of mTOR downstream of AKT signaling augmented axon growth potential in response to CH02. Conclusion: Our study revealed the significant therapeutic effect of CH02 on strengthening nerve regeneration and suggested a strategy for treating peripheral and central nervous system injuries.

Insulin Topical Application for Wound Healing in Nondiabetic Patients.

BACKGROUND: Low-cost and safe strategies to improve wound healing will be of great social and economic value. The goal of this pilot clinical trial is aimed at analyzing how effective insulin therapy is at healing wounds in nondiabetic people. METHODS: In this protocol research, 346 individuals were included. Patients were divided as 2 groups at random: experimental patients were given a ten-unit answer. For each 10 cm2 of wound, insulin was injected in solution with 1 mL 0.9 percent saline, whereas the control group got a standard dressing with normal saline. RESULTS: During the therapy period, no adverse effects were reported. After insulin therapy, no substantial insulin-related side effects were reduced. After 10 days of therapy, the experimental group's granulation tissue coverage rate and thickness were considerably improved as compared to control. Furthermore, a momentous difference in the occurrence of wound bleeding and suppurative wounds between the two groups (P = 0.05). CONCLUSION: The results of this pilot research suggest that insulin injections could harmless and effective alternative therapy for wound healing in nondiabetic individuals and that larger, placebo-controlled trials are needed to evaluate effectiveness and safety of insulin treatment in wound healing patients.

Protective Effect of Total Panax Notoginseng Saponins on Retinal Ganglion Cells of an Optic Nerve Crush Injury Rat Model.

Irreversible loss of retinal ganglion cells (RGCs) is a common pathological feature of various optic nerve degenerative diseases such as glaucoma and ischemic optic neuropathy. Effective protection of RGCs is the key to successful treatment of these diseases. Total Panax notoginseng saponins (TPNS) are the main active component of Panax notoginseng, which has an inhibitory effect on the apoptosis pathway. This study is aimed at assessing the protective effect of TPNS on RGCs of the optic nerve crush (ONC) model of rats and exploring the underlying mechanisms. The intraperitoneal or intravitreal injection of TPNS was used based on the establishment of the rat ONC model. Fifteen days after the injury, the cell membrane fluorescent probe (Fluoro-Gold) was applied to retrograde RGCs through the superior colliculus and obtain the number of surviving RGCs. TUNEL assay was also used to detect the number and density of RGC apoptosis after the ONC model. The expression and distribution of Bcl-2/Bax, c-Jun/P-c-Jun, and P-JNK in the retina were demonstrated by Western blot analysis. After the intervention of TPNS, the rate of cell survival increased in different retinal regions (p < 0.05) and the number of apoptosis cells decreased. Regarding the expression of Bcl-2/Bax, c-Jun/P-c-Jun, and P-JNK-related apoptotic proteins, TPNS can reduce the level of apoptosis and play a role in protecting RGCs (p < 0.05). These findings indicate that topical administration of TPNS can inhibit cell apoptosis and promote RGC survival in the crushed optic nerve.

Diterpene Ginkgolides Meglumine Injection inhibits apoptosis induced by optic nerve crush injury via modulating MAPKs signaling pathways in retinal ganglion cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Diterpene Ginkgolides Meglumine Injection (DGMI) is made of extracts from Ginkgo biloba L, including Ginkgolides A, B, and K and some other contents, and has been widely used as the treatment of cerebral ischemic stroke in clinic. It can be learned from the "Compendium of Materia Medica" that Ginkgo possesses the effect of "dispersing toxin". The ancient Chinese phrase "dispersing toxin" is now explained as elimination of inflammation and oxidative state in human body. And it led to the original ideas for today's anti-oxidation studies of Ginkgo in apoptosis induced by optic nerve crush injury. AIM OF THE STUDY: To investigate the underlying molecular mechanism of the DGMI in retinal ganglion cells (RGCs) apoptosis. MATERIALS AND METHODS: TUNEL staining was used to observe the anti-apoptotic effects of DGMI on the adult rat optic nerve injury (ONC) model, and flow cytometry and hoechst 33,342 staining were used to observe the anti-apoptotic effects of DGMI on the oxygen glucose deprivation (OGD) induced RGC-5 cells injury model. The regulation of apoptosis and MAPKs pathways were investigated with Immunohistochemistry and Western blotting. RESULTS: This study demonstrated that DGMI is able to decrease the conduction time of F-VEP and ameliorate histological features induced by optic nerve crush injury in rats. Immunohistochemistry and TUNEL staining results indicated that DGMI can also inhibit cell apoptosis via modulating MAPKs signaling pathways. In addition, treatment with DGMI markedly improved the morphological structures and decreased the apoptotic index in RGC-5 cells. Mechanistically, DGMI could significantly inhibit cell apoptosis by inhibiting p38, JNK and Erk1/2 activation. CONCLUSION: The study shows that DGMI and ginkgolides inhibit RGCs apoptosis by impeding the activation of MAPKs signaling pathways in vivo and in vitro. Therefore, the present study provided scientific evidence for the underlying mechanism of DGMI and ginkgolides on optic nerve crush injury.

Beneficial effects of bardoxolone methyl, an Nrf2 activator, on crush-related acute kidney injury in rats.

PURPOSE: The purpose of this study was to investigate the effects of bardoxolone methyl (BM), a nuclear factor erythroid 2-related factor 2 (Nrf2) activator, on acute kidney injury in a rat model of crush syndrome model. METHODS: Sixty-four rats were separated equally into eight groups, sham (sterile saline ip), crush, crush + vehicle (DMSO ip), and crush + BM (10 mg/kg ip) (n = 8). All groups were also divided as 3 and 24 h after decompression. Crush injury was induced by 6 h of direct compression to both hind limbs of the rats with blocks weighing 3.6 kg on each side, followed by 3 and 24 h of decompression. Kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), tumor necrotizing factor-α (TNF-α), transforming growth factor-ß1 (TGF-ß1) concentrations, tissue total oxidant status (TOS) and total antioxidant status (TAS) were measured in the kidneys. Serum creatine kinase (CK), blood urea nitrogen (BUN) and creatinine concentrations were also measured. Glomerular and tubular structures were examined histopathologically. Bcl-2 was measured using immunohistochemistry. Apoptosis was assessed using the TUNEL method. RESULTS: BM treatment reduced KIM-1, NGAL, TNF-α, TGF-ß1, TOS concentrations, and increased TAS concentrations in the kidneys 3 and 24 h after decompression. Serum CK, BUN and creatinine concentrations were also reduced with BM. BM treatment decreased apoptosis in crush-related AKI. The Nrf2 activator BM reversed the crush-induced changes in the experimental rats. CONCLUSION: BM treatment prevented the progression of crush-related AKI in rats possibly through its cytoprotective effects of being an antioxidant, anti-inflammatory and anti-apoptotic agent.

Neuroprotective Effect of Nypa fruticans Wurmb by Suppressing TRPV1 Following Sciatic Nerve Crush Injury in a Rat.

Peripheral nerve injury can result in severe functional impairment and decreased quality of life due to loss of sensory and motor function. Nypa fruticans wurmb (NF) has been used in diverse folk remedies in East Asia. We have previously shown that Nypa fruticans wurmb extract has antinociceptive and anti-inflammatory effects by suppressing TRPV1 in the sciatic nerve injury. The present study investigated the effects of NF on the control of TRPV1 in relation to neuroprotective effects of a sciatic nerve crush injury. To evaluate the neuroprotective effects, an animal behavior test and a physiological function test were performed. Functional recovery and nerve recovery were improved in the NF and NF + SB (SB366791; TRPV1 antagonist) treated group. In the histomorphology evaluation, the neuronal regenerative effect of NF on the injured sciatic nerve was confirmed via hematoxylin and eosin (H&E) staining. In this study, the NF and NF + SB treated group showed neuroprotective and functional recovery effects from the sciatic nerve crush injury. Furthermore, the expression of NF-κB and iNOS showed a significantly suppressive effect on NF (p < 0.01), SB (p < 0.01), and NF + SB (p < 0.01) treated group at the 7th and 14th day compared to the vehicle group. This study confirmed the neuroprotective effects of NF on suppressing TRPV1 in a sciatic nerve crush injury. The findings of this study establish the effect of NF as a neurotherapeutic agent to protect the peripheral nerve after a sciatic nerve crush injury.

Strychnos nux-vomica L. seed preparation promotes functional recovery and attenuates oxidative stress in a mouse model of sciatic nerve crush injury.

BACKGROUND: Peripheral nerve injury is a debilitating condition that may lead to partial or complete motor, sensory and autonomic function loss and lacks effective therapy until date. Therefore, it is quite imperative to explore impending remedies for rapid and accurate functional retrieval following such conditions. Natural product-based intervention can prove effective to facilitate the process of functions regain. METHODS: Here, we investigated the effect of processed Strychnos nux-vomica seeds at a dose of 250 mg/kg body weight in a mouse model of induced Sciatic nerve lesion in promoting the recovery of the functions. A compression injury was induced in the Sciatic nerve of the right leg in the mice. Sensory function recovery was evaluated by hot-plate and formalin tests, whereas the motor function retrieval was assessed by measuring muscle grip strength, sciatic functional index, and muscle mass restoration. Oxidative stress and blood cell count were measured by biochemistry and haematological analyses. RESULTS: This study indicates that Strychnos nux-vomica seeds enhance the rate of recovery of both sensory and motor functions. It helps restore the muscle mass, attenuates total oxidant status and enhances the total anti-oxidant capacity of the biological system. Moreover, the treated animals manifested an enhanced glucose tolerance aptitude and augmented granulocyte and platelet counts. Improved oxidant control, enhanced glucose sensitivity and amended granulocyte and platelet counts are likely to contribute to the advantageous effects of Strychnos nux-vomica, and warrant further in-depth studies for deciphering possible mechanisms and identification of active constituent(s) responsible for these effects. CONCLUSION: Strychnos nux-vomica seed offers functional recovery promoting effects following a mechanical injury to the Sciatic nerve and the possible reasons behind this effect can be reduced oxidative stress and improved glycaemic control. Further and detailed investigations can unravel this mystery.

The effect of systemic rifampicin treatment on inferior alveolar nerve regeneration in rats following crush injury.

Axonal regeneration of the inferior alveolar nerve (IAN) is a therapeutic target for functional recovery after peripheral nerve injury. Rifampicin exerts anti-apoptotic, anti-inflammatory, and anti-oxidant effects on nerve tissues that may enhance functional recovery after peripheral nerve injury. The aim of the present study was to evaluate the therapeutic effects of systemic rifampicin following IAN crush injury. Following the nerve crush injuries of the IAN, 24 Sprague-Dawley rats were randomly divided into three groups to receive daily intraperitoneal injections of either vehicle, 5 mg kg-1 rifampicin, or 20 mg kg-1 rifampicin. Twenty-four days after induction of nerve injuries, Fluorogold (FG) was injected over the mental foramen for the evaluation of neuronal survival. At the end of the four-week period, histologic and histomorphometric examination of IAN samples were performed and FG positive cells were counted in the trigeminal ganglion sections. FG positive cells were significantly more frequent in the 20 and 5 mg kg-1 rifampicin groups than in the vehicle-treated group. Electron microscopic analyses revealed that the percentage of axons with optimum g-ratio was significantly lower in the vehicle group than in both treatment groups. In conclusion, systemic rifampicin treatment can enhance peripheral nerve regeneration.

Neurotherapeutic effects of Ginkgo biloba extract and its terpene trilactone, ginkgolide B, on sciatic crush injury model: A new evidence.

Ginkgo biloba leaves extract (GBE) was subjected to neuroprotective-guided fractionation to produce eleven fractions with different polarities and constituents. The intermediate polar fraction was shown to be terpene trilactones-enriched fraction (TEGBE). Out of this fraction, pure ginkgolide B (G-B) was further purified and identified based on its spectral data. The effects of GBE and TEGBE were evaluated in comparison to that of G-B in the crush sciatic nerve injury rat model. To evaluate the neuroprotective effects, sixty Wistar male rats were randomly allocated into 6 groups: naive, sham, crush + normal saline, and three treatment groups; crush + GBE, crush + TEGBE, and crush + G-B. Treatments were given one hour following injury, and once daily for 14 days. Neurobehavioral tests, histomorphological examinations, and immunohistochemical analysis of the sciatic nerve and the spinal cord were performed at weeks 3 and 6 post-injury. GBE, TEGBE and G-B were shown to enhance the functional and sensory behavioral parameters and to protect the histological and the ultrastructural elements in the sciatic nerve. Additionally, all treatments prevented spinal cord neurons from further deterioration. It was shown that G-B has the most significant potential effects among all treatments with values that were nearly comparable to those of sham and naive groups.

Miconazole alleviates peripheral nerve crush injury by mediating a macrophage phenotype change through the NF-κB pathway.

BACKGROUND: Peripheral nerve injury (PNI) causes motor and sensory defects, has strong impact on life quality and still has no effective therapy. Miconazole is one of the most widely used antifungal drugs; the aims of the study were to investigate the effects of miconazole during sciatic nerve regeneration in a mouse model of sciatic nerve crush injury. METHODS: We established peripheral nerve crush model and investigated the effects of miconazole by multiple aspects. We further studied the potential mechanism of action of miconazole by Western blotting, fluorescence immunohistochemistry, and PCR analysis. RESULTS: Miconazole improves the symptoms of crushed nerve by improving inflammatory cell infiltration and demyelinating myelin of sciatic nerve. Affected by miconazole, the proportion of inflammatory M1 macrophages in the distal part of the sciatic nerve was reduced, and the proportion of anti-inflammatory M2 macrophages was increased. Finally, the neuroprotective properties of miconazole may be regulated by the nuclear factor (NF)-κB pathway. CONCLUSIONS: Our data suggest that miconazole can effectively alleviate PNI, and the mechanism involves mediating a phenotype change of M1/ M2 macrophages. Thus, miconazole may represent a potential therapeutic intervention for nerve crush injury.

4-Aminopyridine as a Single Agent Diagnostic and Treatment for Severe Nerve Crush Injury.

BACKGROUND: Traumatic peripheral nerve injury (TPI) is a major medical problem without effective treatment options. There is no way to diagnose or treat an incomplete injury and delays contribute to morbidity. We examined 4-aminopyridine (4-AP), a potassium-channel blocker as a possible treatment for TPI. METHODS: We used standard mouse models of TPI with functional outcomes including sciatic-functional-index, sensory indices, and electrodiagnostics; in addition to standard immunohistochemical, and electron microscopic correlates of axon and myelin morphology. RESULTS: Sustained early 4-AP administration increased the speed and extent of behavioral recovery too rapidly to be explained by axonal regeneration. 4-AP also enhanced recovery of nerve conduction velocity, promoted remyelination, and increased axonal area post-injury. 4-AP treatment also enabled the rapid distinction between incomplete and complete nerve lesions. CONCLUSION: 4-AP singularly provides both a new potential therapy to promote durable recovery and remyelination in acute peripheral nerve injury and a means of identifying lesions in which this therapy would be most likely to be of value. The ability to distinguish injuries that may respond to extended therapy without intervention can offer benefit to wounded soldiers.