Effects of EPC-K1 on lipid peroxidation in experimental spinal cord injury

Free radical scavenger edaravone produces robust neuroprotection in a rat model of spinal cord injury

We used a multimodal approach to evaluate the effects of edaravone in a rat model of spinal cord injury (SCI). SCI was induced by extradural compression of thoracic spinal cord. In experiment 1, 30 min prior to compression, rats received a 3 mg/kg intravenous bolus of edaravone followed by a maintenance infusion of 1 (low-dose), 3 (moderate-dose), or 10 (high-dose) mg/kg/h edaravone. Although both moderate- and high-dose edaravone regimens promoted recovery of spinal motor-evoked potentials (MEPs) at 2 h post-SCI, the effect of the moderate dose was more pronounced. In experiment 2, moderate-dose edaravone was administered 30 min prior to compression, at the start of compression, or 10 min after decompression. Although both preemptive and coincident administration resulted in significantly improved spinal MEPs at 2 h post-SCI, the effect of preemptive administration was more pronounced. A moderate dose of edaravone resulted in significant attenuation of lipid peroxidation, as evidenced by lower concentrations of the free radical malonyldialdehyde in the spinal cord 3 h post-SCI. Malonyldialdehyde levels in the high-dose edaravone group were not reduced. Both moderate- and high-dose edaravone resulted in significant functional improvements, evidenced by better Basso-Beattie-Bresnahan (BBB) scores and better performance on an inclined plane during an 8 week period post-SCI. Both moderate- and high-dose edaravone significantly attenuated neuronal loss in the spinal cord at 8 weeks post-SCI, as evidenced by quantitative immunohistochemical analysis of NeuN-positive cells. In conclusion, early administration of a moderate dose of edaravone minimized the negative consequences of SCI and facilitated functional recovery.

Effects of hyperbaric oxygen therapy on depression and anxiety in the patients with incomplete spinal cord injury (a STROBE-compliant article)

Little research has been done on the effects of hyperbaric oxygen (HBO) on depression and anxiety after spinal cord injury (SCI). The aim of this study was to investigate the effects of HBO on psychological problems and never function, especially on depression and anxiety in the patients with incomplete SCI (ISCI).Sixty patients with ISCI combined with depression and anxiety were randomly divided into HBO group (20 cases), psychotherapy group (20 cases), and conventional rehabilitation control group (20 cases). All patients received routine rehabilitation therapy. However, in HBO group and psychotherapy group, patients also received HBO and psychotherapy, respectively. These therapies lasted for a total of 8 weeks (once a day and 6 days per week). Before and after 8 weeks of treatment, depression and anxiety, nerve function, and activities of daily living were, respectively, evaluated according to Hamilton Depression (HAMD) scale, Hamilton Anxiety (HAMA) scale, American Spinal Injury Association score, and functional independence measure score in all patients.After 8 weeks of treatment, HAMD score was significantly lower in both HBO group and psychotherapy group than in control group (all P < .05), but there was no statistical difference in HAMD score between HBO group and psychotherapy group (P > .05). HAMA score was significantly lower in HBO group than in control group (P < .05), but there was no statistical difference in HAMA score between HBO group and psychotherapy group, and between psychotherapy group and control group (all P > .05). After 8 weeks of treatment, American Spinal Injury Association and functional independence measure scores were significantly higher in HBO group than in both psychological and control groups, and also higher in psychotherapy group than in control group (all P < .05).The effects of HBO on depression and anxiety are similar to that of psychotherapy. HBO can significantly improve nerve function and activities of daily living in the patients with ISCI, which either psychotherapy or routine rehabilitation therapy can not substitute.

Current and future medical therapeutic strategies for the functional repair of spinal cord injury

Spinal cord injury (SCI) leads to social and psychological problems in patients and requires costly treatment and care. In recent years, various pharmacological agents have been tested for acute SCI. Large scale, prospective, randomized, controlled clinical trials have failed to demonstrate marked neurological benefit in contrast to their success in the laboratory. Today, the most important problem is ineffectiveness of nonsurgical treatment choices in human SCI that showed neuroprotective effects in animal studies. Recently, attempted cellular therapy and transplantations are promising. A better understanding of the pathophysiology of SCI started in the early 1980s. Research had been looking at neuroprotection in the 1980s and the first half of 1990s and regeneration studies started in the second half of the 1990s. A number of studies on surgical timing suggest that early surgical intervention is safe and feasible, can improve clinical and neurological outcomes and reduce health care costs, and minimize the secondary damage caused by compression of the spinal cord after trauma. This article reviews current evidence for early surgical decompression and nonsurgical treatment options, including pharmacological and cellular therapy, as the treatment choices for SCI.

Anti-apoptotic and anti-oxidative roles of quercetin after traumatic brain injury

Experimental studies have demonstrated significant secondary damage (including cell apoptosis, blood-brain barrier disruption, inflammatory responses, excitotoxic damage, and free radical production) after traumatic brain injury (TBI). Quercetin is a natural flavonoid found in high quantities in fruits and vegetables, and may be a potential antioxidant and free radical scavenger. The purpose of this study was to determine the effects of quercetin on TBI-induced upregulation of oxidative stress, inflammation, and apoptosis in adult Sprague-Dawley rats. Animals were subjected to Feeney's weight-drop injury, thus inducing the parietal contusion brain injury model. Quercetin was administered (30 mg/kg intraperitoneal injection) 0, 24, 48, and 72 h after TBI. Quercetin reduced cognitive deficits, the number of TUNEL- and ED-1-positive cells, the protein expressions of Bax and cleaved-caspase-3 proteins, and the levels of TBARS and proinflammatory cytokines, and increased the activity of antioxidant enzymes (GSH-Px, SOD, and CAT) at 1 week after TBI. Our results suggest that in TBI rats, quercetin improves cognitive function owing to its neuroprotective action via the inhibition of oxidative stress, leading to a reduced inflammatory response, thereby reducing neuronal death.

Comparison of deferoxamine and methylprednisolone: protective effect of pharmacological agents on lipid peroxidation in spinal cord injury in rats

STUDY DESIGN

Experimental study.

OBJECTIVE

To investigate the protective effect of deferoxamine (DFO) administration in comparison with methylprednisolone (MP) on lipid peroxidation and antioxidants after spinal cord injury (SCI) in rats.

SUMMARY OF BACKGROUND DATA

DFO is used for treating an iron-chelating agent, which is also used in the treatment of iron poisoning and thalassaemia. The neuroprotective effect of DFO was evaulated as a therapeutic agent for SCI.

METHODS

Forty Wistar rats were randomly divided into 5 groups as sham laminectomy (n = 8), laminectomy with SCI (n = 8), laminectomy with SCI and 0.9% saline intraperitoneal (i.p.) (n = 8), laminectomy with SCI and 30 mg/kg MP i.p. (n = 8), and laminectomy with SCI and 30 mg/kg DFO i.p. (n = 8). Neurological deficits were examined 24 hours after trauma, and all rats were killed. Spinal cord segments were harvested for both biochemical and histopathological evaluation.

RESULTS

At 24 hours post-SCI, whereas malondialdehyde levels were increased, superoxide dismutase, catalase, and glutathione peroxidase levels were decreased in groups I, II, and III. MP and DFO treatment decreased MDA levels and increased superoxide dismutase CAT, and glutathione peroxidase levels in control and study groups. There was no statistically significant difference between treatment with MP and DFO (P> 0.05). All rats were paraplegic after SCI, except in the sham group. Histopathological improvement was observed in control and study groups.

CONCLUSION

This study indicates that beneficial effects may be provided and further studies need to investigate the dose-dependent beneficial and side effects of DFO in SCI.

LEVEL OF EVIDENCE

N/A.

Combined hyperbaric oxygen and hypothermia treatment on oxidative stress parameters after spinal cord injury: an experimental study

BACKGROUND AND AIMS

We undertook this study to investigate the possible beneficial effects of combined hypothermia and hyperbaric oxygen (HBO) treatment in comparison with methylprednisolone in experimental spinal cord injury (SCI).

METHODS

Forty eight male Wistar albino rats (200-250 g) were randomized into six groups; A (normothermic control group; only laminectomy), B (normothermic trauma group; laminectomy + spinal trauma), C (normothermic methylprednisolone group; laminectomy + spinal trauma + methylprednisolone treated), D (hypothermia group; laminectomy + spinal trauma + hypothermia treated); E (HBO group; laminectomy + spinal trauma + HBO therapy), F (hypothermia and HBO group; laminectomy + spinal trauma + hypothermia and HBO treated) each containing eight rats. Neurological assessments were performed 24 h after trauma and spinal cord tissue samples had been harvested for both biochemical and histopathological evaluation.

RESULTS

After SCI, tissue malondialdehyde (MDA) level of the control group was measured increased, and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) enzyme activities were measured decreased. In group F, it was also shown that MDA level elevation had been prevented, and group F has increased the antioxidant enzyme activities than the other experimental groups C, D, E (p <0.05).

CONCLUSIONS

We concluded that the use of combined hypothermia and HBO treatment might have potential benefits in spinal cord tissue on secondary damage.

Protective effects of tadalafil on experimental spinal cord injury in rats

Tadalafil is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5). Nitric oxide (NO) functions as a retrograde neurotransmitter in the spinal cord, and postsynaptic structures respond to NO by producing cGMP. The concentrations of cGMP in the spinal cord are controlled by the actions of PDE. The aim of the study was to evaluate and compare the effects of the use of both methylprednisolone and tadalafil on serum and tissue concentrations of NO, malondialdehyde (MDA) levels, superoxide dismutase (SOD) activity, and tissue glutathione peroxidase (GSH-Px) activity in rats with spinal cord injury (SCI). SCI was induced in Wistar albino rats by dropping a 10 g rod from a 5.0 cm height at T8-10. The 28 rats were randomly divided into four equal groups: tadalafil, methylprednisolone, non-treatment and sham groups. Rats were neurologically tested at 24 hours after trauma. At the end of the experiment, blood samples were collected and spinal cord tissue samples were harvested for biochemical evaluation. The tissue level of NO was increased in the tadalafil group compared with the non-treatment and methylprednisolone groups (p<0.05). The tissue levels of SOD and GSH-Px did not differ between the groups. Serum levels of NO were higher in the tadalafil group than in the non-treatment group (p<0.05). The increase in serum SOD levels was greater in the tadalafil group than the methylprednisolone group. Serum MDA levels in the tadalafil and methylprednisolone groups tended to be lower than in the non-treatment group (p>0.05). Tissue MDA levels in the tadalafil and methylprednisolone groups tended to be lower than in the non-treatment group and sham groups (p>0.05). Although there was no difference in neurological outcome scores between the tadalafil, methylprednisolone and non-treatment groups (p>0.05), the animals in the tadalafil and methylprednisolone groups tended to have better scores than the non-treatment group. Thus, tadalafil appears to be beneficial in reducing the effects of injury to the spinal cord by increasing tissue levels of NO and serum activity of SOD.

Effects of hyperbaric oxygen therapy after spinal cord injury: systematic review

OBJECTIVE: to conduct a systematic review of experimental and clinical studies evaluating the effect of hyperbaric oxygen therapy on the spinal cord injury. METHODS: ninety-three studies were identified in the database Pubmed. Among these, through a set of inclusion/exclusion criteria, 11 articles published between 1963 and 2009 were selected. In the nine experimental studies, different ways to apply the treatment were observed. The measured outcomes were: functional, histological, biochemical and electrophysiological. RESULTS: in most of the studies, the results show recovery of locomotor function, histology and/or biochemical features. Regarding the two studies in clinical samples, the results are controversial. The samples are heterogeneous and the application of hyperbaric oxygen therapy is not the same for all patients in each study. CONCLUSION: considering the results of this review, further studies are necessary to define the role of hyperbaric oxygen therapy in acute spinal cord injury.

Does hypothermic treatment provide an advantage after spinal cord injury until surgery? An experimental study

We compared the effects of early and late stage hypothermia treatment after spinal cord injury. Five groups each consisting of seven rats were included in this study. In Group 1a (Clip applied-non-treatment group) and Group 1b (Clip applied-treated group) the spinal cords were harvested 1 h after the injury. In Group 2a (clip applied, non-treated group) and Group 2b (clip applied-treated group) the injured segments were harvested 24 h after injury. Group 3 was designed as the sham-operated group. The significantly lower levels of TBARS and GSH-Px in Group 2a, as compared with Group 1b suggests that the hypothermia was effective in the early stage of treatment (P < 0.05). In contrast, TBARS and GSH-Px levels were significantly increased at the 24 h timepoint following treatment (P < 0.05). Short-term systemic hypothermia reduces lipid peroxidation in the early stages after spinal cord injury. This beneficial effect disappears 24 h following systemic hypothermic treatment.

Effects of methylprednisolone and hyperbaric oxygen on oxidative status after experimental spinal cord injury: a comparative study in rats

The effects of hyperbaric oxygen (HBO) therapy or methylprednisolone on the oxidative status were evaluated in experimental spinal cord injury. Clip compression method was used to produce acute spinal cord injury rats. Hyperbaric oxygen was administered twice daily for a total of eight 90 min-sessions at 2.8 atmospheres. Methylprednisolone was first injected with a bolus of 30 mg/kg followed with an infusion rate of 5.4 mg/kg/h for 24 h. Five days after clip application animals were sacrificed and their traumatized spinal cord segment were excised. Tissue levels of thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were evaluated to reflect oxidant/antioxidant status. Non-treated clip-operated animals reflected significantly higher SOD, GSH-Px and TBARS levels that were found to be significantly higher than the sham-operated. Methylprednisolone was not able to lower these levels. HBO administration diminished all measured parameters significantly; however, their levels appeared already to be high when compared with sham animals. According to these results obtained on the 5th day after induction, HBO, but not methylprednisolone, seems to procure prevention against oxidative spinal cord injury.

Molecular targets in spinal cord injury

The spinal cord can be compared to a highway connecting the brain with the different body levels lying underneath, with the axons being the ultimate carriers of the electrical impulse. After spinal cord injury (SCI), many cells are lost because of the injury. To reconstitute function, damaged axons from surviving neurons have to grow through the lesion site to their initial targets. However, the territory they have to traverse has changed: the highway is full of inhibitory signals (myelin and scar components); the pavement itself has become bumpy (demyelination); and specialized cells are recruited to clear the way (inflammatory cells). Thus, actual strategies to treat spinal injuries aim at providing a permissive environment for regenerating axons and boosting the endogenous potential of axons to regenerate while limiting progression of secondary damage. Here we review some of the strategies currently under consideration to treat spinal injuries.

The antioxidant effect of beta-Glucan on oxidative stress status in experimental spinal cord injury in rats

This study was performed to investigate the antioxidant effect of beta-Glucan in experimental spinal cord injury (SCI). Injury was produced using weight-drop technique in rats. beta-Glucan was given by intraperitoneal injection following trauma. The rats were sacrificed at the sixth day of injury. Oxidative stress status was assessed by measuring the spinal cord tissue content of Malonyldialdehyde (MDA), Superoxide Dismutase (SOD) and Gluthatione Peroxidase (GSH-Px) activities. No effect of beta-Glucan on SOD and MDA activities was found but, GSH-Px levels were found to decrease to the baseline (preinjury) levels when it was compared to untreated group (U=0.000; p=0.002). According to our results, beta-Glucan works like a scavenger and has an antioxidant effect on lipid peroxidation in spinal cord injury.

Correlation of injury severity and tissue Evans blue content, lipid peroxidation and clinical evaluation in acute spinal cord injury in rats

OBJECTIVE

To demonstrate the changes in microvascular permeability occurring in association with graded acute spinal cord injury and to determine whether tissue Evans blue content is a useful indicator of the severity of spinal cord injury. The study also aimed to test the ability of the Evans blue method to demonstrate secondary injury after spinal cord contusion.

METHODS

In step one of the study, spinal cord lipid peroxidation levels and spinal cord Evans blue content were evaluated at 2 h post-injury in five groups of rats: a control group, a laminectomy-only group and three trauma groups (10, 50, and 100 gcm). In step two, these rats were used for Evans blue assessment following clinical examination at 24 h post-injury.

RESULTS

The laminectomy-only group showed no difference from the control group with regard to spinal cord lipid peroxidation levels, tissue Evans blue content, and clinical findings. Increase in spinal cord tissue Evans blue content and lipid peroxidation was correlated with increasing intensity of trauma. There was a negative correlation between trauma intensity and clinical findings, and there was an increase in spinal cord tissue Evans blue content at 24 h compared with that at 2 h.

CONCLUSIONS

Determination of spinal cord tissue Evans blue content is a reliable, rapid, simple and inexpensive method that can be used in experimental spinal cord injury to assess the severity of injury and to evaluate neuroprotection studies. The present study is the first to show that the Evans blue technique is a useful method to demonstrate secondary injury of spinal cord tissue and vasculature.

Effects of antithrombin III on spinal cord-evoked potentials and functional recovery after spinal cord injury in rats

STUDY DESIGN

From the view of motor function, spinal cord-evoked potentials, and histology, we evaluated the effects of antithrombin III on a spinal cord injury resulting in incomplete paraplegia.

OBJECTIVES

To investigate the effect of antithrombin III on the recovery process after acute incomplete rat spinal cord injury.

SUMMARY OF BACKGROUND DATA

Antithrombin III is used for treating disseminated intravascular coagulation by its anticoagulant effect and is also reported to reduce organ damage by the release of prostaglandin I2 from endothelial cells, induced by antithrombin III. Therefore, antithrombin III has potential as a therapeutic agent for spinal cord damage.

METHODS

The spinal cord injury was induced by placing a 25 g weight on the dorsal surface of the spinal cord at the 10th thoracic spine level for 20 minutes. Antithrombin III (250 U/kg) was administered intravenously 5 minutes before the compression, whereas 2 mL of physiologic saline solution was administered to the control group. We recorded the spinal cord-evoked potentials at the T13 level after stimulation of the brain and C7 level. For 12 weeks after the injury, we observed the recovery course of waveform and motor function. The recovery of motor function was evaluated by using inclined table and modified Tarlov scores. We also examined the histology of the compressed site in the spinal cord.

RESULTS

There were statistically significant differences in the motor recovery process between the two groups. Evoked potentials of the antithrombin III group recovered earlier than those of the control group. Histologically, hemorrhage and tissue defects in the spinal cord were less in the antithrombin III group.

CONCLUSION

Because antithrombin III facilitated the recovery of behavior and evoked potentials, these findings suggest that antithrombin III may have a positive effect on the recovery of incomplete spinal cord injury.

Ultrastructural scoring of graded acute spinal cord injury in the rat

OBJECT

There is a need for an accurate quantitative histological technique that also provides information on neurons, axons, vascular endothelium, and subcellular organelles after spinal cord injury (SCI). In this paper the authors describe an objective, quantifiable technique for determining the severity of SCI. The usefulness of ultrastructural scoring of acute SCI was assessed in a rat model of contusion injury.

METHODS

Spinal cords underwent acute contusion injury by using varying weights to produce graded SCI. Adult Wistar rats were divided into five groups. In the first group control animals underwent laminectomy only, after which nontraumatized spinal cord samples were obtained 8 hours postsurgery. The weight-drop technique was used to produce 10-, 25-, 50-, and 100-g/cm injuries. Spinal cord samples were also obtained in the different trauma groups 8 hours after injury. Behavioral assessment and ultrastructural evaluation were performed in all groups. When the intensity of the traumatic injury was increased, behavioral responses showed a decreasing trend. A similar significant negative correlation was observed between trauma-related intensity and ultrastructural scores.

CONCLUSIONS

In the present study the authors characterize quantitative ultrastructural scoring of SCI in the acute, early postinjury period. Analysis of these results suggests that this method is useful in evaluating the degree of trauma and the effectiveness of pharmacotherapy in neuroprotection studies.