Neuroprotective effects of rosuvastatin against traumatic spinal cord injury in rats

Drug Repurposing for Spinal Cord Injury: Progress Towards Therapeutic Intervention for Primary Factors and Secondary Complications

Spinal cord injury (SCI) encompasses a plethora of complex mechanisms like the involvement of major cell death pathways, neurodegeneration of spinal cord neurons, overexpression of glutaminergic transmission and inflammation cascade, along with different co-morbidities like neuropathic pain, urinary and sexual dysfunction, respiratory and cardiac failures, making it one of the leading causes of morbidity and mortality globally. Corticosteroids such as methylprednisolone and dexamethasone, and non-steroidal anti-inflammatory drugs such as naproxen, aspirin and ibuprofen are the first-line treatment options for SCI, inhibiting primary and secondary progression by preventing inflammation and action of reactive oxygen species. However, they are constrained by a short effective drug administration window and their pharmacological action being limited to symptomatic relief of the secondary effects related to spinal cord injury only. Although post-injury rehabilitation treatments may enable functional recovery, they take a long time to show results. Drug repurposing might be an innovative method for expanding therapy alternatives, utilising drugs that are already approved by various esteemed federal agencies throughout the world. Reutilising a drug molecule to treat SCI can eliminate the need for expensive and lengthy drug discovery processes and pave the way for new therapeutic approaches in SCI. This review summarises marketed drugs that could be repurposed based on their safety and efficacy data. We also discuss their mechanisms of action and provide a list of repurposed drugs under clinical trials for SCI therapy.

Ibuprofen use is associated with reduced C-reactive protein and interleukin-6 levels in chronic spinal cord injury

Objective: To assess the association between ibuprofen use and the systemic inflammatory biomarkers C-reactive protein (CRP) and interleukin-6 (IL-6) in chronic Spinal Cord Injury (SCI).Study design: Prospective cohort study.Setting: Community dwelling individuals with SCI.Participants: 338 (278 male, 60 female) community dwelling individuals with chronic SCI (≥1-year post-injury).Interventions: None.Main outcome measures: CRP and IL-6 levels were quantified by ultra-sensitive ELISA assay. General linear models were used to assess associations between various clinical and demographic factors and CRP and IL-6 levels.Results: There were 50 active ibuprofen users and 288 non-users. After adjusting for clinical and demographic factors, ibuprofen users had significantly lower CRP levels (2.3 mg/L versus 3.5 mg/L, P = 0.04) and IL-6 levels (3.2 pg/ml versus 4.0 pg/ml, P = 0.04) compared to nonusers.Conclusions: Our study suggests that self-reported ibuprofen use may be negatively associated with CRP and IL-6 levels in chronic SCI after adjusting for known confounding factors, and suggests ibuprofen use may be an important, potential variable to consider in future studies focused on systemic inflammation in SCI. Future prospective studies require assessing frequency, duration, and dosage-dependent effects of ibuprofen on systemic markers of inflammation in chronic SCI. These findings may support future clinical trials to determine safety and efficacy of ibuprofen treatment for various outcomes in chronic SCI.

Biochemical, pathological and ultrastructural investigation of whether lamotrigine has neuroprotective efficacy against spinal cord ischemia reperfusion injury

INTRODUCTION

Lamotrigine, an anticonvulsant drug with inhibition properties of multi-ion channels, has been shown to be able to attenuates secondary neuronal damage by influencing different pathways. The aim of this study was to look into whether lamotrigine treatment could protect the spinal cord from experimental spinal cord ischemia-reperfusion injury.

MATERIALS AND METHODS

Thirty-two rats, eight rats per group, were randomly assigned to the sham group in which only laparotomy was performed, and to the ischemia, methylprednisolone and lamotrigine groups, where the infrarenal aorta was clamped for thirty minutes to induce spinal cord ischemia-reperfusion injury. Tissue samples belonging to spinal cords were harvested from sacrificed animals twenty-four hours after reperfusion. Tumor necrosis factor-alpha levels, interleukin-1 beta levels, nitric oxide levels, superoxide dismutase activity, catalase activity, glutathione peroxidase activity, malondialdehyde levels and caspase-3 activity were studied. Light and electron microscopic evaluations were also performed to reveal the pathological alterations. Basso, Beattie, and Bresnahan locomotor scale and the inclined-plane test was used to evaluate neurofunctional status at the beginning of the study and just before the animals were sacrificed.

RESULTS

Lamotrigine treatment provided significant improvement in the neurofunctional status by preventing the increase in cytokine expression, increased lipid peroxidation and oxidative stress, depletion of antioxidant enzymes activity and increased apoptosis, all of which contributing to spinal cord damage through different paths after ischemia reperfusion injury. Furthermore, lamotrigine treatment has shown improved results concerning the histopathological and ultrastructural scores and the functional tests.

CONCLUSION

These results proposed that lamotrigine may be a useful therapeutic agent to prevent the neuronal damage developing after spinal cord ischemia-reperfusion injury.

Effects of Ganoderma lucidum Polysaccharides on Different Pathways Involved in the Development of Spinal Cord Ischemia Reperfusion Injury: Biochemical, Histopathologic, and Ultrastructural Analysis in a Rat Model

OBJECTIVE

Inflammation and oxidative stress are 2 important factors in the emergence of paraplegia associated with spinal cord ischemia-reperfusion injury (SCIRI) after thoracoabdominal aortic surgery. Here it is aimed to investigate the effects of Ganoderma lucidum polysaccharide (GLPS) on SCIRI.

METHODS

Rats were randomly selected into 4 groups of 8 animals each: sham, ischemia, methylprednisolone, and GLPS. To research the impacts of various pathways that are efficacious in formation of SCIRI, tumor necrosis factor α, interleukin 1β, nitric oxide, superoxide dismutase levels, and catalase, glutathione peroxidase activities, malondialdehyde levels, and caspase-3 activity were measured in tissues taken from the spinal cord of rats in all groups killed 24 hours after ischemia reperfusion injury. The Basso, Beattie, and Bresnahan locomotor scale and inclined plane test were used for neurologic assessment before and after SCIRI. In addition, histologic and ultrastructural analyses of tissue samples in all groups were performed.

RESULTS

SCIRI also caused marked increase in tissue tumor necrosis factor α, interleukin 1β, nitric oxide, malondialdehyde levels, and caspase-3 activity, because of inflammation, increased free radical generation, lipid peroxidation, and apoptosis, respectively. On the other hand, SCIRI caused significant reduction in tissue superoxide dismutase, glutathione peroxidase, and catalase activities. Pretreatment with GLPS likewise diminished the level of the spinal cord edema, inflammation, and tissue injury shown by pathologic and ultrastructural examination. Pretreatment with GLPS reversed all these biochemical changes and improved the altered neurologic status.

CONCLUSIONS

These outcomes propose that pretreatment with GLPS prevents progression of SCIRI by alleviating inflammation, oxidation, and apoptosis.

Evaluation of the neuroprotective effects of ozone in an experimental spine injury model

OBJECTIVE

The pathophysiology of spine injury consists of primary and secondary damage mechanisms. The vast majority of treatments aim to prevent or at least stop the progression of secondary neurotoxic events during the acute period. Ozone has been found to have potent antiinflammatory effects, to activate the immune system, and to have a substantial impact on the antioxidant system. In this study the authors aimed to evaluate the neuroprotective effects of ozone and their possible roles in recovery from spine injury, assessed based on biochemical, histological, and neurological parameters using an experimental spine injury model in rats.

METHODS

The study included 31 female Wistar albino rats. The rats were divided randomly into 5 groups, with 7 rats in each group except the sham group, which contained 3 rats, as follows: group 1 (sham), laminectomy; group 2 (control), laminectomy and spinal trauma with no medical treatment (0.5 ml isotonic saline applied 1 hour postsurgery); group 3, single medical treatment with 30 mg/kg methylprednisolone applied intraperitoneally 1 hour after laminectomy and trauma; group 4, single medical treatment with 60 μg/ml ozone at 0.7 mg/kg applied intraperitoneally 1 hour after laminectomy and trauma; and group 5, double medical treatment with 30 mg/kg methylprednisolone and 60 μg/ml ozone at 0.7 mg/kg applied intraperitoneally 1 hour after laminectomy and trauma. After neurosurgery, neurobehavioral tests were performed in all groups. After 7 days of follow-up, all the rats were killed. Biopsy specimens obtained from trauma sites were examined using H & E, cresyl violet, immunohistochemical (anticonnexin-43), and TUNEL staining processes. Levels of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) and total oxidant status (TOS) and total antioxidant status (TAS) were measured in blood samples.

RESULTS

The level of neurobehavioral healing was the highest in the double-treatment group (group 5), and the difference between the groups was significant. The minimum IL-6 level was found in group 5, indicating that the antiinflammatory impact was the most significant in this group (p = 0.01). Additionally, ozone was found to reduce oxidant stress more effectively than methylprednisolone (p = 0.03). Although methylprednisolone was superior to ozone in terms of the antiinflammatory effect, this effect was greater in group 5. Nevertheless, the number of neurons in group 5 was close to that of the control group, and the number of apoptotic cells was the least in group 5 (p < 0.001).

CONCLUSIONS

In acute spinal injury, the combined application of methylprednisolone and ozone was found to have a greater antiinflammatory effect, hasten clinical recovery, and increase histological recovery compared with methylprednisolone therapy alone. This study showed that this combination therapy of methylprednisolone with the addition of ozone might have a more beneficial effect in the treatment of spinal injury than methylprednisolone therapy alone.

The Effect of Exosomes Derived from Bone Marrow Stem Cells in Combination with Rosuvastatin on Functional Recovery and Neuroprotection in Rats After Ischemic Stroke

Rosuvastatin, known as a cholesterol-lowering agent, has been used as an alternative therapy after the onset of stroke. In this study, neuroprotection and functional recovery of exosomes in combination with rosuvastatin have been investigated. Sixty adult male Wistar rats were subjected to middle cerebral artery occlusion (MCAO). Exosome at the dose of 100 μg and/or rosuvastatin at the dose of 20 mg/kg/day for 7 days were administered to rats as a therapeutic strategy. The elevated body swing test (EBST) and Garcia score were conducted as behavioral tests for the measurement of functional recovery. The histopathological and immunohistochemical analyses were also performed for the assessment of infarcted volume and neuroprotection in the brain of rats. The real-time PCR method was carried out to determine the relative expressions of the NLRP-3 and NLRP1 genes. After 7 days of treatment with exosome and rosuvastatin in rats which underwent MCAO, the decrease in infarct volume of the animals treated with exosome was more pronounced compared with those treated only with exosome. The combination therapy remarkably lowered the size of infarct volume. Our observation was confirmed by the downregulation of the NLRP1 and NLRP3 genes in response to combinatory treatment of rats induced by MCOA, denoting a lower rate of cell death. The number of GFAP-positive cells were reduced in the exosome-treated group compared with the MCAO group. The rate of lipid peroxidation was measured by malondialdehyde (MDA) levels which demonstrated a significant reduction of MDA in the exosome- and rotuvastatin-treated groups when compared with the MCAO group. However, the levels of the SOD enzyme did not significantly alter when the treatment groups were compared with the MCAO group. According to our findings, it seems that the use of exosomes and rosuvastatin, as a novel treatment regimen, might promote neurological recovery after the onset of stroke.

Unfolding the pleiotropic facades of rosuvastatin in therapeutic intervention of myriads of neurodegenerative disorders

Rosuvastatin, a 3-hydroxy-3-methylglutaryl-coenzyme (HMG-CoA) reductase inhibitor, and one of the most popular antihyperlipidemic medications have been found to possess pharmacodynamic activities much different from its usual indication. Recent research studies have revealed the efficacy of rosuvastatin in attenuating neuroinflammation, reducing the progression of Alzheimer's disease, providing protection against cerebral ischaemia and spinal cord injury as well as ameliorating epilepsy. Mechanisms behind the neuroprotective potential of rosuvastatin can be attributed to its pleiotropic effects, independent of its ability to inhibit HMG-CoA reductase. These processes include modulation of several cellular pathways, isoprenylation, effects on oxidative stress, nitrosative levels, inflammation, and immune response. This review aims to assimilate and summarize recent findings on the pharmacological actions of rosuvastatin in attenuating neurological disorders in order to guide future research in this space.

Rosuvastatin Reduces Neuroinflammation in the Hemorrhagic Transformation After rt-PA Treatment in a Mouse Model of Experimental Stroke

Hemorrhagic transformation (HT) is a serious complication that stimulates inflammation during reperfusion therapy after acute ischemic stroke. Rosuvastatin, a 3-hydroxymethyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, might improve the outcome of HT by inhibiting neuroinflammation. This study aimed to explore the protective effects of rosuvastatin against HT after recombinant tissue plasminogen activator (rt-PA) treatment in mice with experimental stroke via the attenuation of inflammation. A total of one hundred sixty-nine male BALB/c mice were used in the experiment. HT was successfully established in 70 mice that were subjected to 3 h of middle cerebral artery occlusion (MCAO) followed by a 10 mg/kg rt-PA injection over 10 min and reperfusion for 24 h. The mice were then administered rosuvastatin (1 mg/kg, 5 mg/kg) or saline (vehicle). The brain water content and neurological deficits (wire hang and adhesive removal somatosensory tests) were assessed at 24 h after rt-PA reperfusion following MCAO surgery. The morphology, blood-brain barrier (BBB) permeability and number of astrocytes and microglia were assessed by immunohistochemistry, electron microscopy and western blotting at 24 h after rt-PA reperfusion following MCAO surgery. Rosuvastatin protected against impaired neurological function and reversed the BBB leakage observed in the HT group. The increased activation of astrocytes and microglia and secretion of inflammatory factors caused by HT damage were significantly attenuated by high-dose rosuvastatin treatment vs. normal-dose rosuvastatin treatment. Related inflammatory pathways, such as the nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways, were downregulated in the rosuvastatin-treated groups compared with the HT group. In conclusion, our results indicate that rosuvastatin is a promising therapeutic agent for HT after rt-PA reperfusion following MCAO surgery in mice, as it attenuates neuroinflammation. Additionally, high-dose rosuvastatin treatment could have a greater anti-inflammatory effect on HT than normal-dose rosuvastatin treatment.

Rosuvastatin Improves Neurite Outgrowth of Cortical Neurons against Oxygen-Glucose Deprivation via Notch1-mediated Mitochondrial Biogenesis and Functional Improvement

Neurogenesis, especially neurite outgrowth is an essential element of neuroplasticity after cerebral ischemic injury. Mitochondria may supply ATP to power fundamental developmental processes including neuroplasticity. Although rosuvastatin (RSV) displays a potential protective effect against cerebral ischemia, it remains unknown whether it modulates mitochondrial biogenesis and function during neurite outgrowth. Here, the oxygen-glucose deprivation (OGD) model was used to induce ischemic injury. We demonstrate that RSV treatment significantly increases neurite outgrowth in cortical neurons after OGD-induced damage. Moreover, we show that RSV reduces the generation of reactive oxygen species (ROS), protects mitochondrial function, and elevates the ATP levels in cortical neurons injured by OGD. In addition, we found that, under these conditions, RSV treatment increases the mitochondrial DNA (mtDNA) content and the mRNA levels of mitochondrial transcription factor A (TFAM) and nuclear respiratory factor 1 (NRF-1). Furthermore, blocking Notch1, which is expressed in primary cortical neurons, reverses the RSV-dependent induction of mitochondrial biogenesis and function under OGD conditions. Collectively, these results suggest that RSV could restore neurite outgrowth in cortical neurons damaged by OGD in vitro, by preserving mitochondrial function and improving mitochondrial biogenesis, possibly through the Notch1 pathway.

CoQ10 Augments Rosuvastatin Neuroprotective Effect in a Model of Global Ischemia via Inhibition of NF-κB/JNK3/Bax and Activation of Akt/FOXO3A/Bim Cues

Statins were reported to lower the Coenzyme Q10 (CoQ10) content upon their inhibition of HMG-CoA reductase enzyme and both are known to possess neuroprotective potentials; therefore, the aim is to assess the possible use of CoQ10 as an adds-on therapy to rosuvastatin to improve its effect using global I/R model. Rats were allocated into sham, I/R, rosuvastatin (10 mg/kg), CoQ10 (10 mg/kg) and their combination. Drugs were administered orally for 7 days before I/R. Pretreatment with rosuvastatin and/or CoQ10 inhibited the hippocampal content of malondialdehyde, nitric oxide, and boosted glutathione and superoxide dismutase. They also opposed the upregulation of gp91^phox, and p47^phox subunits of NADPH oxidase. Meanwhile, both agents reduced content/expression of TNF-α, iNOS, NF-κBp65, ICAM-1, and MPO. Besides, all regimens abated cytochrome c, caspase-3 and Bax, but increased Bcl-2 in favor of cell survival. On the molecular level, they increased p-Akt and its downstream target p-FOXO3A, with the inhibition of the nuclear content of FOXO3A to downregulate the expression of Bim, a pro-apoptotic gene. Additionally, both treatments downregulate the JNK3/c-Jun signaling pathway. The effect of the combination regimen overrides that of either treatment alone. These effects were reflected on the alleviation of the hippocampal damage in CA1 region inflicted by I/R. Together, these findings accentuate the neuroprotective potentials of both treatments against global I/R by virtue of their rigorous multi-pronged actions, including suppression of hippocampal oxidative stress, inflammation, and apoptosis with the involvement of the Akt/FOXO3A/Bim and JNK3/c-Jun/Bax signaling pathways. The study also nominates CoQ10 as an adds-on therapy with statins.

Curcumin Attenuates Inflammation, Oxidative Stress, and Ultrastructural Damage Induced by Spinal Cord Ischemia-Reperfusion Injury in Rats

OBJECTIVES

Curcumin is a molecule found in turmeric root that possesses anti-inflammatory and antioxidant properties and has been widely used to treat neurodegenerative diseases. We investigated whether curcumin stimulates the neurorepair process and improves locomotor function in a rat model of spinal cord ischemia-reperfusion injury.

METHODS

Thirty-two Wistar albino rats (190-220 g) were randomly allocated into 4 groups of 8 rats each: 1 sham-operated group and 3 ischemia-reperfusion injury groups that received intraperitoneal injections of saline vehicle, methylprednisolone (MP, 30 mg/kg following induction of ischemia-reperfusion [IR] injury), or curcumin (200 mg/kg for 7 days before induction of IR injury). Spinal cord IR injury was induced by occlusion of the abdominal aorta for 30 minutes. After 24 hours of reperfusion, locomotor function was assessed using the Basso, Beattie, and Bresnahan scale. All animals were sacrificed. Spinal cord tissues were harvested to evaluate histopathological and ultrastructural alterations and to analyze levels of malondialdehyde, tumor necrosis factor-alpha, interleukin-1 beta, nitric oxide, and caspase-3, as well as enzyme activities of superoxide dismutase and glutathione peroxidase.

RESULTS

Intraperitoneal administration of curcumin significantly reduced inflammatory cytokine expression, attenuated oxidative stress and lipid peroxidation, prevented apoptosis, and increased antioxidant defense mechanism activity in comparison to treatment with MP or saline. Histopathological and ultrastructural abnormalities were significantly reduced in curcumin-treated rats compared to the MP- and saline-treated groups. Furthermore, curcumin significantly improved locomotor function.

CONCLUSIONS

Curcumin treatment preserves neuronal viability against inflammation, oxidative stress, and apoptosis associated with ischemia-reperfusion injury.

Molecular mechanisms underlying the effects of statins in the central nervous system

3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, commonly referred to as statins, are widely used in the treatment of dyslipidaemia, in addition to providing primary and secondary prevention against cardiovascular disease and stroke. Statins’ effects on the central nervous system (CNS), particularly on cognition and neurological disorders such as stroke and multiple sclerosis, have received increasing attention in recent years, both within the scientific community and in the media. Current understanding of statins’ effects is limited by a lack of mechanism-based studies, as well as the assumption that all statins have the same pharmacological effect in the central nervous system. This review aims to provide an updated discussion on the molecular mechanisms contributing to statins’ possible effects on cognitive function, neurodegenerative disease, and various neurological disorders such as stroke, epilepsy, depression and CNS cancers. Additionally, the pharmacokinetic differences between statins and how these may result in statin-specific neurological effects are also discussed.