Salvianolic acid B attenuates spinal cord ischemia-reperfusion-induced neuronal injury and oxidative stress by activating the extracellular signal-regulated kinase pathway in rats

Salvianolic acid B ameliorates Aβ42 toxicity in Aβ42-expressing Drosophila model: behavioral and transcriptomic profiling

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases worldwide. It is characterized by the accumulation of amyloid-beta (Aβ) plaques in which Aβ42 is the most toxic and aggressive species. This work investigates the possibility of salvianolic acid B (SalB), a natural compound with established neuroprotective activity, to counteract the Aβ42-induced toxicity in a Drosophila melanogaster model of AD. SalB's effect was assessed in the Aβ42-expressing Drosophila model by measuring three major AD-related behavioural symptoms: eye morphology (cytotoxicity), lifespan, and locomotor activity. The eye assay, longevity, and locomotion assays were employed, followed by RNA sequencing (RNA-seq) to identify molecular alterations following SalB treatment. Aβ42 expression in the Aβ42-expressing Drosophila model resulted in deformed eye morphology, reduced lifespan, and motor impairment. Treatment with SalB restored part of eye morphology, extended lifespan, and improved locomotion. RNA-seq revealed differential gene expression in oxidative phosphorylation, glutathione metabolism, and detoxification processes, suggesting the involvement of antioxidant defence in SalB-mediated neuroprotection. These findings indicate that SalB could be therapeutic for AD and other neurodegenerative disorders, possibly through the modulation of oxidative stress against Aβ42 toxicity. Further research is warranted to address its mechanisms and other uses in neurodegenerative therapy.

Blood-spinal cord barrier disruption in degenerative cervical myelopathy

Degenerative cervical myelopathy (DCM) is the most prevalent cause of spinal cord dysfunction in the aging population. Significant neurological deficits may result from a delayed diagnosis as well as inadequate neurological recovery following surgical decompression. Here, we review the pathophysiology of DCM with an emphasis on how blood-spinal cord barrier (BSCB) disruption is a critical yet neglected pathological feature affecting prognosis. In patients suffering from DCM, compromise of the BSCB is evidenced by elevated cerebrospinal fluid (CSF) to serum protein ratios and abnormal contrast-enhancement upon magnetic resonance imaging (MRI). In animal model correlates, there is histological evidence of increased extravasation of tissue dyes and serum contents, and pathological changes to the neurovascular unit. BSCB dysfunction is the likely culprit for ischemia-reperfusion injury following surgical decompression, which can result in devastating neurological sequelae. As there are currently no therapeutic approaches specifically targeting BSCB reconstitution, we conclude the review by discussing potential interventions harnessed for this purpose.

3D Gelatin Microsphere Scaffolds Promote Functional Recovery after Spinal Cord Hemisection in Rats

Spinal cord injury (SCI) damages signal connections and conductions, with the result that neuronal circuits are disrupted leading to neural dysfunctions. Such injuries represent a serious and relatively common central nervous system condition and current treatments have limited success in the reconstruction of nerve connections in injured areas, especially where sizeable gaps are present. Biomaterial scaffolds have become an effective alternative to nerve transplantation in filling these gaps and provide the foundation for simulating the 3D structure of solid organs. However, there remain some limitations with the application of 3D bioprinting for preparation of biomaterial scaffolds. Here, the approach in constructing and testing mini-tissue building blocks and self-assembly, solid 3D gelatin microsphere (GM) scaffolds with multiple voids as based on the convenient preparation of gelatin microspheres by microfluidic devices is described. These 3D GM scaffolds demonstrate suitable biocompatibility, biodegradation, porosity, low preparation costs, and relative ease of production. Moreover, 3D GM scaffolds can effectively bridge injury gaps, establish nerve connections and signal transductions, mitigate inflammatory microenvironments, and reduce glial scar formation. Accordingly, these 3D GM scaffolds can serve as a novel and effective bridging method to promote nerve regeneration and reconstruction and thus recovery of nerve function after SCI.

Astragaloside IV ameliorates spinal cord injury through controlling ferroptosis in H2O2-damaged PC12 cells in vitro

BACKGROUND

Spinal cord injury (SCI) is associated with significant paralysis and high fatality. Recent research has revealed that ferroptosis participates in the pathogenesis of SCI. Astragaloside IV (AS-IV), the main active ingredient of the plant Astragalus membranaceus, has been reported to promote motor function recovery in rats with SCI. This study explored the effects of AS-IV in H2O2-treated PC12 pheochromocytoma cells.

METHODS

The optimal concentration and duration of AS-IV treatment in PC12 cells was assessed using the cell counting kit 8 (CCK-8) assay. Subsequently, the SCI cell model was established in PC12 cells using H2O2. The effects of AS-IV, FIN56, and transcription factor EB (TFEB) small interfering (si)RNA on cell viability and apoptosis in the SCI model were determined using the CCK-8 assay and flow cytometry, respectively. Caspase‑3 and lactate dehydrogenase (LDH) levels were measured by colorimetric assay and enzyme-linked immunosorbent assay (ELISA), respectively. Cellular reactive oxygen species (ROS) were detected by flow cytometry combined with dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay. The cellular ultrastructure was analyzed by transmission electron microscopy (TEM). The ferroptosis pathway-related proteins were confirmed using Western blot analysis. TFEB expression was confirmed by Western blot and immunofluorescence.

RESULTS

The optimal concentration and duration of AS-IV treatment in PC12 cells was determined to be 1.0 µM and 48 h, respectively. AS-IV markedly accelerated proliferation, suppressed apoptosis, and reduced ROS and LDH accumulation. Furthermore, AS-IV enhanced TFEB expression in H2O2-damaged PC12 cells. The effects of AS-IV on SCI were inhibited by si-TFEB, and this inhibition was further reinforced by the addition of FIN56.

CONCLUSIONS

The results of this investigation using the SCI cell model suggested that AS-IV alleviated SCI by promoting TFEB expression and subsequently mediating ferroptosis. This may represent a potential clinical treatment for SCI.

Application of natural antioxidants from traditional Chinese medicine in the treatment of spinal cord injury

Spinal cord injury (SCI) is a devastating central nervous system disease, caused by physical traumas. With the characteristic of high disability rate, catastrophic dysfunction, and enormous burden on the patient’s family, SCI has become a tough neurological problem without efficient treatments. Contemporarily, the pathophysiology of SCI comprises complicated and underlying mechanisms, in which oxidative stress (OS) may play a critical role in contributing to a cascade of secondary injuries. OS substantively leads to ion imbalance, lipid peroxidation, inflammatory cell infiltration, mitochondrial disorder, and neuronal dysfunction. Hence, seeking the therapeutic intervention of alleviating OS and appropriate antioxidants is an essential clinical strategy. Previous studies have reported that traditional Chinese medicine (TCM) has antioxidant, anti-inflammatory, antiapoptotic and neuroprotective effects on alleviating SCI. Notably, the antioxidant effects of some metabolites and compounds of TCM have obtained numerous verifications, suggesting a potential therapeutic strategy for SCI. This review aims at investigating the mechanisms of OS in SCI and highlighting some TCM with antioxidant capacity used in the treatment of SCI.

Attenuation Effect of Salvianolic Acid B on Testicular Ischemia-Reperfusion Injury in Rats

During testicular ischemia-reperfusion, overproduction of reactive oxygen species is associated with testicular injury. We injected hydrogen peroxide (a representative of reactive oxygen species) into normal testis via the testicular artery. The experiment demonstrates that reactive oxygen species can cause spermatogenic injury. Salvianolic acid B, the most abundant bioactive component in Salvia miltiorrhiza Bunge, has been reported to possess a potent antioxidant activity. This study was conducted to evaluate the effect of salvianolic acid B on testicular ischemia-reperfusion injury in a rat testicular torsion-detorsion model. Rats were randomly separated into three groups, including 20 rats in each group: control group with sham operation, testicular ischemia-reperfusion group, and testicular ischemia-reperfusion + salvianolic acid B-treated group. In the testicular ischemia-reperfusion group, left testicular torsion of 720° for 2 hours was induced, and then testicular detorsion was carried out. Rats in the salvianolic acid B-treated group additionally had salvianolic acid B administered intravenously at detorsion. At 4 hours after detorsion, testes of 10 rats from each group were collected to analyze the protein expression of xanthine oxidase which catalyzes generation of reactive oxygen species and malondialdehyde concentration (an indirect indicator of reactive oxygen species). At 3 months after detorsion, testes of the remaining 10 rats from each group were collected to analyze spermatogenesis. Compared with the control group, xanthine oxidase protein expression and malondialdehyde concentration in ipsilateral testes of testicular ischemia-reperfusion group increased significantly, while spermatogenesis decreased significantly. In the salvianolic acid B-treated group, xanthine oxidase protein expression and malondialdehyde concentration in ipsilateral testes decreased significantly, while spermatogenesis increased significantly, compared with the testicular ischemia-reperfusion group. These results suggest that salvianolic acid B can attenuate testicular torsion/detorsion-induced ischemia/reperfusion injury by downregulating the xanthine oxidase protein expression to inhibit reactive oxygen species formation.

Neuroinflammation and Modulation Role of Natural Products After Spinal Cord Injury

Spinal cord injury (SCI) is a severe traumatic injury of the central nervous system, characterized by neurological dysfunction and locomotor disability. Although the underlying pathological mechanism of SCI is complex and remains unclear, the important role of neuroinflammation has been gradually unveiled in recent years. The inflammation process after SCI involves disruption of the blood–spinal cord barrier (BSCB), activation of gliocytes, infiltration of peripheral macrophages, and feedback loops between different cells. Thus, our first aim is to illustrate pathogenesis, related cells and factors of neuroinflammation after SCI in this review. Due to the good bioactivity of natural products derived from plants and medicinal herbs, these widely exist as food, health-care products and drugs in our lives. In the inflammation after SCI, multiple natural products exert satisfactory effects. Therefore, the second aim of this review is to sum up the effects and mechanisms of 25 natural compounds and 7 extracts derived from plants or medicinal herbs on neuroinflammation after SCI. Clarification of the SCI inflammation mechanism and a summary of the related natural products is helpful for in-depth research and drug development.

5-Aminolevulinic acid combined with sodium ferrous citrate (5-ALA/SFC) ameliorated liver injury in a murine acute graft-versus-host disease model by reducing inflammation responses through PGC1-α activation

Acute graft-versus-host disease (aGvHD) remains lethal as a life-threatening complication after allogeneic hematopoietic stem cell transplantation (HSCT). Inflammatory responses play an important role in aGvHD. 5-Aminolevulinic acid combined with sodium ferrous citrate (5-ALA/SFC) has been widely reported to have a major effect on the anti-inflammatory response; however, these effects in aGvHD models have never been reported. In this study, a murine aGvHD model was developed by transferring spleen cells from donor B6/N (H-2kb) mice into recipient B6D2F1 (H-2kb/d) mice. In addition to evaluating manifestations in aGvHD mice, we analyzed the serum ALT/AST levels, liver pathological changes, infiltrating cells and mRNA expression of inflammation-related cytokines and chemokines. 5-ALA/SFC treatment significantly ameliorated liver injury due to aGvHD and decreased the population of liver-infiltrating T cells, resulting in a reduced expression of pro-inflammatory cytokines and chemokines. Furthermore, the mRNA expression proliferator-activated receptor-γcoactivator (PGC-1α) was enhanced, which might explain why 5-ALA/SFC treatment downregulates inflammatory signaling pathways. Our results indicated that 5-ALA/SFC can ameliorate liver injury induced by aGvHD through the activation of PGC-1α and modulation of the liver mRNA expression of inflammatory-related cytokines and chemokines. This may be a novel strategy for treating this disease.

Erythropoietin-Induced Autophagy Protects Against Spinal Cord Injury and Improves Neurological Function via the Extracellular-Regulated Protein Kinase Signaling Pathway

The objective of this study was to explore the neuroprotective molecular mechanisms of erythropoietin (EPO) in rats following spinal cord injury (SCI). First, a standard SCI model was established. After drug or saline treatment was administered, locomotor function was evaluated in rats using the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale. H&E, Nissl, and TUNEL staining were performed to assess the ratio of cavities, number of motor neurons, and apoptotic cells in the damaged area. The relative protein and mRNA expressions were examined using western blot and qRT-PCR analyses, and the inflammatory markers, axon special protein, and neuromuscular junctions (NMJs) were detected by immunofluorescence. Both doses of EPO notably improved locomotor function, but high-dose EPO was more effective than low-dose EPO. Moreover, EPO reduced the cavity ratio, cell apoptosis, and motor neuron loss in the damaged area, but enhanced the autophagy level and extracellular-regulated protein kinase (ERK) activity. Treatment with an ERK inhibitor significantly prevented the effect of EPO on SCI, and an activator mimicked the benefits of EPO. Further investigation revealed that EPO promoted SCI-induced autophagy via the ERK signaling pathway. EPO activates autophagy to promote locomotor function recovery in rats with SCI via the ERK signaling pathway.

Salvianolic acid B activates Wnt/β-catenin signaling following spinal cord injury

Neural cell apoptosis serves a key role in spinal cord injury (SCI), which is a threat to human health. The present study aimed to evaluate the neuroprotective mechanism of salvianolic acid B (Sal B) in a spinal cord injury (SCI) rat model. Basso, Beattie, and Bresnahan scores demonstrated that Sal B treatment significantly increased locomotor functional recovery in SCI rats compared with SCI model rats between 3 and 8 weeks. Nissl staining demonstrated that Sal B enhanced motor neuron survival and decreased lesion size after SCI. Reverse transcription-quantitative PCR analysis demonstrated that Sal B treatment significantly enhanced the mRNA levels of lymphoid enhancer biding factor-1 and HNF1 homeobox A. In addition, Sal B treatment enhanced the expression of β-catenin. Western blot analysis determined that Sal B treatment significantly decreased the expression of pro-apoptosis proteins, including Bax, cleaved caspase-3 and -9, in spinal cord tissues after SCI but enhanced the expression of Bcl-2, an anti-apoptotic protein. Furthermore, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining demonstrated that, compared with the SCI group, Sal B treatment decreased the number of TUNEL-positive neurons. In summary, the present study produced novel data demonstrating the neuroprotective effect of Sal B on SCI with the mechanism likely primarily mediated via the Wnt/β-catenin signaling pathway. The present findings may be of potential therapeutic value for future SCI treatments.

Danshen extract (Salvia miltiorrhiza Bunge) attenuate spinal cord injury in a rat model: A metabolomic approach for the mechanism study

BACKGROUD

Spinal cord injury (SCI) is a devastating neurological disorder caused by trauma. To date, SCI treatment is still a significant challenge in clinic and research around the world. Danshen (dried roots and rhizomes of Salvia miltiorrhiza), a commonly used Chinese medicinal herb, has been attracting attention in SCI treatment.

PURPOSE

Aim of this study was to evaluate the potential beneficial effects of danshen extract in a SCI rat model, as well as investigate possible mechanism of action and potential biomarkers.

METHODS

Here, a rat SCI model was established with weight-drop method, and danshen extract was administered by oral gavage (12.5 g/kg). Recovery of motor function and histomorphological changes were evaluated by Basso, Beattie and Bresnahan score and hematoxylin-eosin staining, respectively. In addition, neurofilament 200 (NF-H), brain-derived neurotrophic factor (BDNF), glial fibrillary acidic protein (GFAP) and CD11b expressions were assayed by immunofluorescence and western blot analysis. Furthermore, a metabolomics analysis based on ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) approach was conducted.

RESULTS

The results demonstrated that danshen extract could significantly ameliorated histopathology changes and improved recovery of motor function after SCI. Moreover, NF-H, BDNF and CD11b expression were progressively increased until 4 weeks post-injury after administrated danshen extract. Furthermore, a good separation was observed among different groups using OPLS-DA. Trajectory analysis showed the gradual shift from position of model group toward normal group with increasing time after administration of danshen extract. Meanwhile, 51 significantly altered metabolites were identified, while metabolic pathway analysis suggested that 6 metabolic pathways were disturbed by the altered metabolites.

CONCLUSION

In summary, this study provides an overview of neuroprotective effects and investigates possible mechanism of danshen extract in SCI treatment. However, further research is needed to uncover its regulatory mechanisms more clearly.

Comparative pharmacokinetic study on phenolic acids and flavonoids in spinal cord injury rats plasma by UPLC-MS/MS after single and combined oral administration of danshen and huangqin extract

Chinese medicinal herbs danshen and huangqin have attracted attention in spinal cord injury (SCI) treatment. Purpose of this study was to investigate and compare the pharmacokinetic characteristics of 4 phenolic acids and 4 flavonoids in SCI rat plasma after orally administrate danshen, huangqin and combined extract of these two herbs (CDH). Thus, a rapid and sensitive ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for simultaneously quantitative determination of tanshinol, protocatechualdehyde, protocatechuic acid, salvianolic acid A, baicalein, baicalin, wogonin and wogonoside. After inducing a contusion injury by a weight-drop device, SCI rats were orally administrated a single dose (12.5 g/kg) of danshen, huangqin and CDH extracts, respectively. Then, blood samples at different time points were collected and analyzed. In CDH group, C_max and AUC of tanshinol, protocatechualdehyde and protocatechuic acid significantly declined, while those of salvianolic acid A enhanced. These changes were beneficial for danshen to treat SCI. As for flavonoids, double peaks were observed in huangqin group, while this phenomenon disappeared in CDH group. Concomitantly, C_max and AUC declined after administrated CDH. These alterations were due to influence of danshen active constituents on absorption and transportation process of flavonoids. Therefore, danshen and huangqin significantly influenced pharmacokinetic profile and parameters of each other, thus exert synergistic therapeutic effect in SCI treatment.

Salvianolic acid B ameliorates liver injury in a murine aGvHD model by decreasing inflammatory responses via upregulation of HO-1

Acute graft-versus-host disease (aGvHD) remains lethal, even after allogeneic hematopoietic stem cell transplantation. Inflammatory responses play an important role in aGvHD. Salvianolic acid B (Sal B) has been widely reported to have a major effect on the anti-inflammatory response, but these effects in an aGvHD model have never been reported. B6 donor splenocytes were transplanted into unirradiated BDF1 recipients and liver and serum were collected on day 14 after transplantation with or without Sal B administration. We measured the expression of pro-inflammatory cytokines and chemokines and other manifestations in aGvHD mice after Sal B treatment. Sal B ameliorated liver injury in aGvHD and promoted survival in mice. Sal B treatment resulted in decreased expression of pro-inflammatory cytokines and chemokines whose expressions in liver are normally elevated by aGvHD. Furthermore, Sal B treatment also enhanced PGC-1α expression in liver tissue and HO-1 expression in nonparenchymal cells. In addition, HO-1 inhibitor abrogated the improvement of survival rate of mice with aGvHD. These results indicated that the protective effect of Sal B relies on suppressing the inflammatory response phase in the aGvHD model, presumably by inducing HO-1. Taken together our data showed that Sal B ameliorates liver injury in aGvHD by decreasing inflammatory responses via upregulation of HO-1. It may provide a novel way to deal with this disease.

Salvianolic acid B, an antioxidant derived from Salvia militarize, protects mice against γ‑radiation‑induced damage through Nrf2/Bach1

Salvianolic acid B (SB) is an antioxidant derived from Salvia militarize, and is one of the most widely used herbs in traditional Chinese medicine. SB is a potent antioxidant that has been well documented as a scavenger of oxygen free radicals, and has been used for the prevention and treatment of atherosclerosis-associated disorders. To explore its potential therapeutic effects in treating radiation damage, in this study, mice were treated with SB at different doses of 5, 12.5 and 20 mg/kg, subsequent to receiving γ-irradiation. The effects of SB on peripheral blood, bone marrow nucleated cells, spleen and thymus indices, and oxidation resistance were evaluated in both radiated mice and control groups. The results indicated that SB significantly increased the counts of peripheral white blood cells, red blood cells and platelets. The number of nucleated cells in the bone marrow and the level of protein increased as well. In addition, improved spleen and thymus indices in the bone marrow were observed. SB treatment additionally reversed the deterioration of both the thymus and spleen indices, which is associated with increased serum superoxide dismutase activity and decreasing malondialdehyde levels via nuclear factor (erythroid-derived 2)-like 2 protein/BTB and CNC homology 1 mediated antioxidant effect. Furthermore, ROS levels and Bax protein expression were also suppressed by SB. The data suggested that SB is effective in protecting mice from γ-radiation injury, and could potentially be applicable for clinical use. Notably, the present study identified a promising candidate drug for enhancing the hematopoietic and immune systems.

Effects of Derinat on ischemia-reperfusion-induced pressure ulcer mouse model

Sodium salt of deoxyribonucleic acid (DNA), Derinat, isolated from the soft roes of Russian sturgeon, has been utilized as an immunomodulator for the treatment of reactive oxygen species (ROS)-associated diseases in clinics. Here we show that treatment with Derinat has an anti-inflammatory and anti-oxidative effects on cutaneous ischemia-reperfusion (IR) injury in pressure ulcer (PU) model mice. Dorsal skin damage and dermal edema in mild PU model mice were attenuated by treatment with Derinat. Immunohistochemical and biochemical analyses showed that Derinat suppressed IR-induced oxidative damage, i.e. accumulation of 8-hydroxy-2'-deoxyguanosine (8-OHdG), and related inflammatory factors such as cyclooxygenase 2 (COX-2) and IL-6 receptor (IL-6R) in dorsal skin from PU model mice. We also verified that phospholyated/non-phosphorylated ratio of extracellular signal-regulated kinase (Erk) and p38 mitogen-activated protein kinase (MAPK) increased after IR, which were attenuated by Derinat. We then compared the effect of Derinat with that of salmon DNA and other PU therapeutic agents, prostaglandin E1 (PGE1) and basic fibroblast growth factor (bFGF), by using severe PU model mice. The effects of Derinat and salmon-DNA were compatible with those of PGE1 and bFGF. These results suggest that Derinat other fish-derived DNA formulation could be effective enough and become intriguing new therapeutic options.

Cerebroprotection by salvianolic acid B after experimental subarachnoid hemorrhage occurs via Nrf2- and SIRT1-dependent pathways

Salvianolic acid B (SalB), a natural polyphenolic compound extracted from the herb of Salvia miltiorrhiza, possesses antioxidant and neuroprotective properties and has been shown to be beneficial for diseases that affect vasculature and cognitive function. Here we investigated the protective effects of SalB against subarachnoid hemorrhage (SAH)-induced oxidative damage, and the involvement of underlying molecular mechanisms. In a rat model of SAH, SalB inhibited SAH-induced oxidative damage. The reduction in oxidative damage was associated with suppressed reactive oxygen species generation; decreased lipid peroxidation; and increased glutathione peroxidase, glutathione, and superoxide dismutase activities. Concomitant with the suppressed oxidative stress, SalB significantly reduced neurologic impairment, brain edema, and neural cell apoptosis after SAH. Moreover, SalB dramatically induced nuclear factor-erythroid 2-related factor 2 (Nrf2) nuclear translocation and increased expression of heme oxygenase-1 and NADPH: quinine oxidoreductase-1. In a mouse model of SAH, Nrf2 knockout significantly reversed the antioxidant effects of SalB against SAH. Additionally, SalB activated sirtuin 1 (SIRT1) expression, whereas SIRT1-specific inhibitor sirtinol pretreatment significantly suppressed SalB-induced SIRT1 activation and Nrf2 expression. Sirtinol pretreatment also reversed the antioxidant and neuroprotective effects of SalB. In primary cultured cortical neurons, SalB suppressed oxidative damage, alleviated neuronal degeneration, and improved cell viability. These beneficial effects were associated with activation of the SIRT1 and Nrf2 signaling pathway and were reversed by sirtinol treatment. Taken together, these in vivo and in vitro findings suggest that SalB provides protection against SAH-triggered oxidative damage by upregulating the Nrf2 antioxidant signaling pathway, which may be modulated by SIRT1 activation.

The study of traditional Chinese medical elongated-needle therapy promoting neurological recovery mechanism after spinal cord injury in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Acupuncture is a key part of traditional Chinese medicine, shown to induce favorable neuroplasticity for injuries in the central and peripheral nervous systems. Recent studies report elongated needle therapy (ENT) with BL54 and ST28 may restore acute spinal cord injury (ASCI). However, the precise mechanism for this has not been elucidated.

AIM OF THE STUDY

In our current study, we investigated the effects of ENT on inflammation and neuronal apoptosis induced by ASCI, and whether PI3K/Akt and MAPK/ERK signaling pathways are involved in the ENT restoration effect.

MATERIALS AND METHODS

Rat models of moderate SCI were established in accordance with the modified Allen's method and were treated with ENT continuously for 7 days. Spontaneous activities were evaluated by the Basso Beattie and Bresnahan locomotor scale. Levels of inflammatory cytokines, such as tumor necrosis factor alpha, interleukin-6, IL-1β, and nuclear factor kappa-β, were determined by enzyme-linked immunosorbent assay. Cell apoptosis was examined by the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The proportions of cells with positive Bcl-2 and Bax expression were determined by immunohistochemical assays, whilst the expression profiles of p-AKT and p-ERK in spinal cord tissues were evaluated by western blotting. Furthermore, the expression profiles of Cytochrome-C (Cyt-C) and caspase-3 in vivo were analyzed by reverse transcription polymerase chain reaction. The potential inhibitory effects downstream of the Akt and ERK signaling pathways were examined by administration of specific inhibitors LY294002 and PD98059 in vivo.

RESULTS

As indicated by this study, inflammation as well as PI3K/Akt- and MAPK/ERK signaling pathway-mediated neuronal apoptosis were involved in the course of SCI in rats. The neuro-protective effect of ENT was associated with reduced Bax protein-positive neurons and increased Bcl-2 protein-positive neurons. ENT enhanced recovery of rat activities. Activation of p-Akt and p-ERK in the PI3K/Akt and MAPK/ERK signaling pathways, inhibited expression of the critical component Cyt-C. Cyt-C is required for the mitochondrial apoptosis pathway and cascade of caspase-3, which is involved in activation of neuronal apoptosis through down-regulation of Bax protein and up-regulation of Bcl-2, as determined by TUNEL. The administration of PI3K/Akt and MAPK/ERK signaling pathway specific inhibitors, LY294002 and PD98059, suppressed expression of both p-Akt and p-ERK.

CONCLUSION

ENT with BL54 and ST28 points can promote the recovery of ASCI. And the neuro-protective effect of ENT during the restoration of SCI may be associated with the suppression of both inflammation and activation of PI3K/Akt and MAPK/ERK signaling pathways, resulting from down-regulation of Bax protein, up-regulation of Bcl-2, and inhibition of the mitochondrial apoptosis pathway.

Aged Garlic Extract Attenuates Neuronal Injury in a Rat Model of Spinal Cord Ischemia/Reperfusion Injury

Garlic has been used as a food as well as a component of traditional medicine. Aged garlic extract (AGE) is claimed to promote human health through antioxidant/anti-inflammatory activities with neuroprotective effects. We evaluated the possible beneficial effect of AGE neurologically, pathologically, ultrastructurally, and biochemically in a spinal cord ischemia-reperfusion (I/R) model of rats. Twenty-four Sprague-Dawley rats were divided into three groups: sham (no I/R), I/R, and AGE (I/R+AGE); each group consisted of eight animals. Animals were evaluated neurologically with the Basso, Beattie, and Bresnahan (BBB) scoring system. The spinal cord tissue samples were harvested for pathological and ultrastructural examinations. Oxidative products (Malondialdehyde, nitric oxide), antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase), inflammatory cytokines (tissue tumor necrosis factor alpha, interleukin-1), and caspase-3 activity were analyzed. The AGE group had significantly higher BBB scores than the I/R group. Pathologically, AGE group revealed reduced degree of ischemia and spinal cord edema. Ultrastructural results also showed preservation of tissue structure in the AGE group. Oxidative product levels of the I/R group were significantly higher than both the other groups, and antioxidant enzyme levels of AGE group were significantly higher than the I/R group. There was also significant difference between the sham and AGE groups in terms of total antioxidant enzyme levels. Furthermore, AGE treatment significantly reduced the inflammatory cytokines and caspase-3 activity than the I/R group. This study demonstrates the considerable neuroprotective effect of AGE on the neurological, pathological, ultrastructural, and biochemical status of rats with I/R-induced spinal cord injury.

Salvianolic acid B protects the myelin sheath around injured spinal cord axons

Salvianolic acid B, an active pharmaceutical compound present in Salvia miltiorrhiza, exerts a neuroprotective effect in animal models of brain and spinal cord injury. Salvianolic acid B can promote recovery of neurological function; however, its protective effect on the myelin sheath after spinal cord injury remains poorly understood. Thus, in this study, in vitro tests showed that salvianolic acid B contributed to oligodendrocyte precursor cell differentiation, and the most effective dose was 20 μg/mL. For in vivo investigation, rats with spinal cord injury were intraperitoneally injected with 20 mg/kg salvianolic acid B for 8 weeks. The amount of myelin sheath and the number of regenerating axons increased, neurological function recovered, and caspase-3 expression was decreased in the spinal cord of salvianolic acid B-treated animals compared with untreated control rats. These results indicate that salvianolic acid B can protect axons and the myelin sheath, and can promote the recovery of neurological function. Its mechanism of action is likely to be associated with inhibiting apoptosis and promoting the differentiation and maturation of oligodendrocyte precursor cells.

The Mechanism Research of Qishen Yiqi Formula by Module-Network Analysis

Qishen Yiqi formula (QSYQ) has the effect of tonifying Qi and promoting blood circulation, which is widely used to treat the cardiovascular diseases with Qi deficiency and blood stasis syndrome. However, the mechanism of QSYQ to tonify Qi and promote blood circulation is rarely reported at molecular or systems level. This study aimed to elucidate the mechanism of QSYQ based on the protein interaction network (PIN) analysis. The targets' information of the active components was obtained from ChEMBL and STITCH databases and was further used to search against protein-protein interactions by String database. Next, the PINs of QSYQ were constructed by Cytoscape and were analyzed by gene ontology enrichment analysis based on Markov Cluster algorithm. Finally, based on the topological parameters, the properties of scale-free, small world, and modularity of the QSYQ's PINs were analyzed. And based on function modules, the mechanism of QSYQ was elucidated. The results indicated that Qi-tonifying efficacy of QSYQ may be partly attributed to the regulation of amino acid metabolism, carbohydrate metabolism, lipid metabolism, and cAMP metabolism, while QSYQ improves the blood stasis through the regulation of blood coagulation and cardiac muscle contraction. Meanwhile, the “synergy” of formula compatibility was also illuminated.

The secretome of apoptotic human peripheral blood mononuclear cells attenuates secondary damage following spinal cord injury in rats

After spinal cord injury (SCI), secondary damage caused by oxidative stress, inflammation, and ischemia leads to neurological deterioration. In recent years, therapeutic approaches to trauma have focused on modulating this secondary cascade. There is increasing evidence that the success of cell-based SCI therapy is due mainly to secreted factors rather than to cell implantation per se. This study investigated peripheral blood mononuclear cells as a source of factors for secretome- (MNC-secretome-) based therapy. Specifically, we investigated whether MNC-secretome had therapeutic effects in a rat SCI contusion model and its possible underlying mechanisms. Rats treated with MNC-secretome showed substantially improved functional recovery, attenuated cavity formation, and reduced acute axonal injury compared to control animals. Histological evaluation revealed higher vascular density in the spinal cords of treated animals. Immunohistochemistry showed that MNC-secretome treatment increased the recruitment of CD68(+) cells with concomitant reduction of oxidative stress as reflected by lower expression of inducible nitric oxide synthase. Notably, MNC-secretome showed angiogenic properties ex vivo in aortic rings and spinal cord tissue, and experiments showed that the angiogenic potential of MNC-secretome may be regulated by CXCL-1 upregulation in vivo. Moreover, systemic application of MNC-secretome activated the ERK1/2 pathway in the spinal cord. Taken together, these results indicate that factors in MNC-secretome can mitigate the pathophysiological processes of secondary damage after SCI and improve functional outcomes in rats.

Ginsenoside Rd attenuates mitochondrial permeability transition and cytochrome C release in isolated spinal cord mitochondria: involvement of kinase-mediated pathways

Ginsenoside Rd (Rd), one of the main active ingredients in Panax ginseng, has multifunctional activity via different mechanisms and neuroprotective effects that are exerted probably via its antioxidant or free radical scavenger action. However, the effects of Rd on spinal cord mitochondrial dysfunction and underlying mechanisms are still obscure. In this study, we sought to investigate the in vitro effects of Rd on mitochondrial integrity and redox balance in isolated spinal cord mitochondria. We verified that Ca²⁺ dissipated the membrane potential, provoked mitochondrial swelling and decreased NAD(P)H matrix content, which were all attenuated by Rd pretreatment in a dose-dependent manner. In contrast, Rd was not able to inhibit Ca²⁺ induced mitochondrial hydrogen peroxide generation. The results of Western blot showed that Rd significantly increased the expression of p-Akt and p-ERK, but had no effects on phosphorylation of PKC and p38. In addition, Rd treatment significantly attenuated Ca²⁺ induced cytochrome c release, which was partly reversed by antagonists of Akt and ERK, but not p-38 inhibitor. The effects of bisindolylmaleimide, a PKC inhibitor, on Rd-induced inhibition of cytochrome c release seem to be at the level of its own detrimental activity on mitochondrial function. Furthermore, we also found that pretreatment with Rd in vivo (10 and 50 mg/kg) protected spinal cord mitochondria against Ca²⁺ induced mitochondrial membrane potential dissipation and cytochrome c release. It is concluded that Rd regulate mitochondrial permeability transition pore formation and cytochrome c release through protein kinases dependent mechanism involving activation of intramitochondrial Akt and ERK pathways.