Resveratrol treatment of spinal cord injury in rat model

Research Progress of Antioxidants in Oxidative Stress Therapy after Spinal Cord Injury

Spinal cord injury (SCI) is a serious problem in the central nervous system resulting in high disability and mortality with complex pathophysiological mechanisms. Oxidative stress is one of the main secondary reactions of SCI, and its main pathophysiological marker is the production of excess reactive oxygen species. The overproduction of reactive oxygen species and insufficient antioxidant capacity lead to the occurrence of oxidative stress and neuroinflammation, and the dysregulation of oxidative stress and neuroinflammation leads to further aggravation of damage. Oxidative stress can initiate a variety of inflammatory and apoptotic pathways, and targeted antioxidant therapy can greatly reduce oxidative stress and reduce neuroinflammation, which has a certain positive effect on rehabilitation and prognosis in SCI. This article reviewed the research on different types of antioxidants and related treatments in SCI, focusing on the mechanisms of oxidative stress.

Pathophysiology and Therapeutic Approaches for Spinal Cord Injury

Spinal cord injury (SCI) is a disabling condition that disrupts motor, sensory, and autonomic functions. Despite extensive research in the last decades, SCI continues to be a global health priority affecting thousands of individuals every year. The lack of effective therapeutic strategies for patients with SCI reflects its complex pathophysiology that leads to the point of no return in its function repair and regeneration capacity. Recently, however, several studies started to uncover the intricate network of mechanisms involved in SCI leading to the development of new therapeutic approaches. In this work, we present a detailed description of the physiology and anatomy of the spinal cord and the pathophysiology of SCI. Additionally, we provide an overview of different molecular strategies that demonstrate promising potential in the modulation of the secondary injury events that promote neuroprotection or neuroregeneration. We also briefly discuss other emerging therapies, including cell-based therapies, biomaterials, and epidural electric stimulation. A successful therapy might target different pathologic events to control the progression of secondary damage of SCI and promote regeneration leading to functional recovery.

Protective Effect of Resveratrol against Hypoxia-Induced Neural Oxidative Stress

Oxidative stress plays an important role in brain aging and in neurodegenerative diseases. New therapeutic agents are necessary to cross the blood–brain barrier and target disease pathogenesis without causing disagreeable side effects. Resveratrol (RSV) may act as a neuroprotective compound, but little is known about its potential in improving the cognitive and metabolic aspects that are associated with neurodegenerative diseases. The objective of this study was to investigate the protective effects and the underlying mechanisms of RSV against hypoxia-induced oxidative stress in neuronal PC12 cells. For the induction of the hypoxia model, the cells were exposed to oxygen-deprived gas in a hypoxic chamber. Cell cycle and apoptosis were analyzed by a fluorescence activated cell sorting (FACS) analysis. The intracellular reactive oxygen species (ROS) level was analyzed by using dichlorodihydrofluorescein diacetate (DCFDA) and 5-(and-6)-chloromethyl-2’,7’-dichlorodihydrofluorescein diacetate, acetyl ester (CM-H2DCFDA) tests. The expression of activated caspase-3, -9, Bcl-2, Bax, p53, and SOD was investigated by a Western blot analysis. We found that hypoxia reduced PC12 viability by inducing apoptosis, while RSV treatment attenuated the ROS-induced damage by reducing caspase-3, -9, and the Bax/Bcl-2 ratio. The RSV treated groups were found to improve cellular health, with a 7.41% increase in the S phase population in the 10 µM group, compared to the control. Hence, RSV has a protective effect in neuronal cells and may halt the cell cycle in the G1/S phase to repair the intracellular damage. Therefore, RSV could be a good candidate to act as an antioxidant and promising preventive therapeutic agent in neurodegenerative diseases for personalized medicine.

Antioxidant Therapy in Oxidative Stress-Induced Neurodegenerative Diseases: Role of Nanoparticle-Based Drug Delivery Systems in Clinical Translation

Free radicals are formed as a part of normal metabolic activities but are neutralized by the endogenous antioxidants present in cells/tissue, thus maintaining the redox balance. This redox balance is disrupted in certain neuropathophysiological conditions, causing oxidative stress, which is implicated in several progressive neurodegenerative diseases. Following neuronal injury, secondary injury progression is also caused by excessive production of free radicals. Highly reactive free radicals, mainly the reactive oxygen species (ROS) and reactive nitrogen species (RNS), damage the cell membrane, proteins, and DNA, which triggers a self-propagating inflammatory cascade of degenerative events. Dysfunctional mitochondria under oxidative stress conditions are considered a key mediator in progressive neurodegeneration. Exogenous delivery of antioxidants holds promise to alleviate oxidative stress to regain the redox balance. In this regard, natural and synthetic antioxidants have been evaluated. Despite promising results in preclinical studies, clinical translation of antioxidants as a therapy to treat neurodegenerative diseases remains elusive. The issues could be their low bioavailability, instability, limited transport to the target tissue, and/or poor antioxidant capacity, requiring repeated and high dosing, which cannot be administered to humans because of dose-limiting toxicity. Our laboratory is investigating nanoparticle-mediated delivery of antioxidant enzymes to address some of the above issues. Apart from being endogenous, the main advantage of antioxidant enzymes is their catalytic mechanism of action; hence, they are significantly more effective at lower doses in detoxifying the deleterious effects of free radicals than nonenzymatic antioxidants. This review provides a comprehensive analysis of the potential of antioxidant therapy, challenges in their clinical translation, and the role nanoparticles/drug delivery systems could play in addressing these challenges.

Effects of Polyphenols on Oxidative Stress, Inflammation, and Interconnected Pathways during Spinal Cord Injury

Despite the progression in targeting the complex pathophysiological mechanisms of neurodegenerative diseases (NDDs) and spinal cord injury (SCI), there is a lack of effective treatments. Moreover, conventional therapies suffer from associated side effects and low efficacy, raising the need for finding potential alternative therapies. In this regard, a comprehensive review was done regarding revealing the main neurological dysregulated pathways and providing alternative therapeutic agents following SCI. From the mechanistic point, oxidative stress and inflammatory pathways are major upstream orchestras of cross-linked dysregulated pathways (e.g., apoptosis, autophagy, and extrinsic mechanisms) following SCI. It urges the need for developing multitarget therapies against SCI complications. Polyphenols, as plant-derived secondary metabolites, have the potential of being introduced as alternative therapeutic agents to pave the way for treating SCI. Such secondary metabolites presented modulatory effects on neuronal oxidative stress, neuroinflammatory, and extrinsic axonal dysregulated pathways in the onset and progression of SCI. In the present review, the potential role of phenolic compounds as critical phytochemicals has also been revealed in regulating upstream dysregulated oxidative stress/inflammatory signaling mediators and extrinsic mechanisms of axonal regeneration after SCI in preclinical and clinical studies. Additionally, the coadministration of polyphenols and stem cells has shown a promising strategy for improving post-SCI complications.

Resveratrol promotes axonal regeneration after spinal cord injury through activating Wnt/β-catenin signaling pathway

Background: Spinal cord injury (SCI) is characterized by autonomic dysreflexia, chronic pain, sensory and motor deficits. Resveratrol has shown potential neuroprotective function in several neurodegenerative diseases’ models. However, if resveratrol could improve the function recovery after SCI and the further mechanism have not been investigated.

Methods: SCI rat model was established through laminectomy at lamina T9-10 aseptically. Basso, beattie and bresnahan (BBB) and inclined plane score, sensory recovery, spinal cord content, and inflammatory factors were measured. The levels of GAP43, NF421, GFAP, Bax, Bcl-2 and caspase-3 were measured using immunohistochemical staining. Tunel staining was applied to detect apoptosis level.

Results: Resveratrol significantly improved the function recovery, promoted axonal regeneration, suppressed apoptosis after SCI. The activation of Wnt/β-catenin signaling pathway was achieved by resveratrol. XAV939 significantly reversed the influence of resveratrol on function recovery, axonal regeneration, apoptosis after SCI.

Conclusions: Resveratrol could promote the function recovery and axonal regeneration, improve histological damage, inhibit apoptosis level after SCI through regulating Wnt/β-catenin signaling pathway. This research expanded the regulatory mechanism of resveratrol in SCI injury.

Resveratrol on the Inflammatory Environment of Rat Bone Marrow Mesenchymal Cells

Our study assesses the mechanism of Sirt-1 signaling pathway and inflammation changes after spinal cord injury (SCI). SD rats were assigned into Sham group and SCI group. The Sham group only received bites off the corresponding vertebral lamina without the blow operation. The Western Blot method was used to detect Sirt-1 level, ELISA analyzed IL-1β and IL-6 level in the spinal cord tissues along with measuring Sirt-1 and TNF-α level by immunofluorescence staining. Sirt-1 changed with the time after SCI and was significantly higher than sham operation group at 1 day after injury, reaching the highest level at 3 days followed by a decrease. IL-1β and IL-6 after SCI was significantly higher than sham operation group at 1 day after injury. Immunofluorescence double staining showed that Sirt-1 and TNF-α expression in spinal cord tissue after injury were upregulated. The expression of Sirt-1 changed with time after SCI, and was consistent with the trend of changes in inflammatory factors. In conclusion, Sirt-1 is related to the changes of inflammatory factors after SCI, indicating that Sirt-1 may be involved in inflammation after SCI.

Antioxidant, anti-inflammatory and neuroprotective actions of resveratrol after experimental nervous system insults. Special focus on the molecular mechanisms involved

After different types of acute central nervous system insults, including stroke, subarachnoid haemorrhage and traumatic brain and spinal cord injuries, secondary damage plays a central role in the induction of cell death, neurodegeneration and functional deficits. Interestingly, secondary cell death presents an attractive target for clinical intervention because the temporal lag between injury and cell loss provides a potential window for effective treatment. While primary injuries are the direct result of the precipitating insult, secondary damage involves the activation of pathological cascades through which endogenous factors can exacerbate initial tissue damage. Secondary processes, usually interactive and overlapping, include oxidative stress, neuroinflammation and dysregulation of autophagy, ultimately leading to cell death. Resveratrol, a natural stilbene present at relatively high concentrations in grape skin and red wine, exerts a wide range of beneficial health effects. Within the central nervous system, in addition to its inherent free radical scavenging role, resveratrol increases endogenous cellular antioxidant defences thus modulating multiple synergistic pathways responsible for its antioxidant, anti-inflammatory and anti-apoptotic properties. During the last years, a growing body of in vitro and in vivo evidence has been built, indicating that resveratrol can induce a neuroprotective state and attenuate functional deficits when administered acutely after an experimental injury to the central nervous system. In this review, we summarize the most recent findings on the molecular pathways involved in the neuroprotective effects of this multi target polyphenol, and discuss its neuroprotective potential after brain or spinal cord injuries.

Nutritional interventions for spinal cord injury: preclinical efficacy and molecular mechanisms

Spinal cord injury (SCI) is a debilitating condition that leads to motor, sensory, and autonomic impairments. Its intrinsic pathophysiological complexity has hindered the establishment of effective treatments for decades. Nutritional interventions (NIs) for SCI have been proposed as a route to circumvent some of the problems associated with this condition. Results obtained in animal models point to a more holistic effect, rather than to specific modulation, of several relevant SCI pathophysiological processes. Indeed, published data have shown NI improves energetic imbalance, oxidative damage, and inflammation, which are promoters of improved proteostasis and neurotrophic signaling, leading ultimately to neuroprotection and neuroplasticity. This review focuses on the most well-documented Nis. The mechanistic implications and their translational potential for SCI are discussed.

Hormetic Effects of Bioactive Compounds from Foods, Beverages, and Food Dressing: The Potential Role in Spinal Cord Injury

Spinal cord injury (SCI) is a damage or trauma to the spinal cord resulting in a total or partial loss of motor and sensory function. SCI is characterized by a disequilibrium between the production of reactive oxygen species and the levels of antioxidant defences, causing oxidative stress and neuroinflammation. This review is aimed at highlighting the hormetic effects of some compounds from foods, beverages, and food dressing that are able to reduce oxidative stress in patients with SCI. Although curcumin, ginseng, and green tea have been proposed for SCI management, low levels of antioxidant vitamins have been reported in individuals with SCI. Mediterranean diet includes food rich in vitamins and antioxidants. Moreover, food dressing, including spices, herbs, and extra virgin olive oil (EVOO), contains multiple components with hormetic effects. The latter involves the activation of the nuclear factor erythroid-derived 2, consequently increasing the antioxidant enzymes and decreasing inflammation. Furthermore, EVOO improves the bioavailability of carotenoids and could be a delivery system for bioactive compounds. In conclusion, Mediterranean dressing in addition to plant foods can have an important effect on redox balance in individuals with SCI.

Research progress in use of traditional Chinese medicine for treatment of spinal cord injury

BACKGROUND

Spinal cord injury (SCI) is a serious central nervous system disorder caused by trauma that has gradually become a major challenge in clinical medical research. As an important branch of worldwide medical research, traditional Chinese medicine (TCM) is rapidly moving towards a path of reform and innovation. Therefore, this paper systematically reviews research related to existing TCM treatments for SCI, with the aims of identifying deficits and shortcomings within the field, and proposing feasible alternative prospects.

METHODS

All data and conclusions in this paper were obtained from articles published by peers in relevant fields. PubMed, SciFinder, Google Scholar, Web of Science, and CNKI databases were searched for relevant articles. Results regarding TCM for SCI were identified and retrieved, then manually classified and selected for inclusion in this review.

RESULTS

The literature search identified a total of 652 articles regarding TCM for SCI. Twenty-eight treatments (16 active ingredients, nine herbs, and three compound prescriptions) were selected from these articles; the treatments have been used for the prevention and treatment of SCI. In general, these treatments involved antioxidative, anti-inflammatory, neuroprotective, and/or antiapoptotic effects of TCM compounds.

CONCLUSIONS

This paper showed that TCM treatments can serve as promising auxiliary therapies for functional recovery of patients with SCI. These findings will contribute to the development of diversified treatments for SCI.