Therapeutic potential of flavonoids in spinal cord injury

Potential effects and mechanism of flavonoids extract of Callicarpa nudiflora Hook on DSS-induced colitis in mice

Callicarpa nudiflora Hook (C. nudiflora) is an anti-inflammatory, antimicrobial, antioxidant, and hemostatic ethnomedicine. To date, little has been reported regarding the activity of C. nudiflora against ulcerative colitis (UC). In this study, we investigated the effect of a flavonoid extract of C. nudiflora on Dextran Sulfate Sodium (DSS)-induced ulcerative colitis in mice. Mice in the treatment group (CNLF+DSS group) and drug-only (CNLF group) groups were administered 400 mg/kg of flavonoid extract of C. nudiflora leaf (CNLF), and drinking water containing 2.5 % DSS was given to the model and treatment groups. The symptoms of colitis were detected, relevant indicators were verified, intestinal barrier function was assessed, and the contents of the cecum were analyzed for intestinal microorganisms. The results showed that CNLF significantly alleviated the clinical symptoms and histological morphology of colitis in mice, inhibited the increase in pro-inflammatory factors (TNF-α, IL-6, IL-1β, and IFN-γ), and increased the level of IL-10. The expression of NF-κB and MAPK inflammatory signal pathway-related proteins (p-p65, p-p38, p-ERK, p-JNK) was regulated. The expression of tight junction proteins (ZO-1, OCLDN, and CLDN1) was increased, while the content of D-LA, DAO, and LPS was decreased. In addition, 16S rRNA sequencing showed that CNLF restored the gut microbial composition, and increased the relative abundance of Prevotellaceae, Intestinimonas butyriciproducens, and Barnesiella_intestinihominis. In conclusion, CNLF alleviated colitis by suppressing inflammation levels, improving intestinal barrier integrity, and modulating the intestinal microbiota, and therefore has promising future applications in the treatment of UC.

The role of apoptosis in spinal cord injury: a bibliometric analysis from 1994 to 2023

Background

Apoptosis after spinal cord injury (SCI) plays a pivotal role in the secondary injury mechanisms, which cause the ultimate neurologic insults. A better understanding of the molecular and cellular basis of apoptosis in SCI allows for improved glial and neuronal survival via the administrations of anti-apoptotic biomarkers. The knowledge structure, development trends, and research hotspots of apoptosis and SCI have not yet been systematically investigated.

Methods

Articles and reviews on apoptosis and SCI, published from 1st January 1994 to 1st Oct 2023, were retrieved from the Web of Science™. Bibliometrix in R was used to evaluate annual publications, countries, affiliations, authors, sources, documents, key words, and hot topics.

Results

A total of 3,359 publications in accordance with the criterions were obtained, which exhibited an ascending trend in annual publications. The most productive countries were the USA and China. Journal of Neurotrauma was the most impactive journal; Wenzhou Medical University was the most prolific affiliation; Cuzzocrea S was the most productive and influential author. "Apoptosis," "spinal-cord-injury," "expression," "activation," and "functional recovery" were the most frequent key words. Additionally, "transplantation," "mesenchymal stemness-cells," "therapies," "activation," "regeneration," "repair," "autophagy," "exosomes," "nlrp3 inflammasome," "neuroinflammation," and "knockdown" were the latest emerging key words, which may inform the hottest themes.

Conclusions

Apoptosis after SCI may cause the ultimate neurological damages. Development of novel treatments for secondary SCI mainly depends on a better understanding of apoptosis-related mechanisms in molecular and cellular levels. Such therapeutic interventions involve the application of anti-apoptotic agents, free radical scavengers, as well as anti-inflammatory drugs, which can be targeted to inhibit core events in cellular and molecular injury cascades pathway.

Neural regeneration ability of Polypyrrole-Collagen-Quercetin composite in the spinal cord injury

Spinal cord injury (SCI) is a major clinical problem in young patients. The major hurdle in SCI regeneration is the replacement of lost nerve communication signals due to injury. Here we have prepared a biocompatible electrical conductive composite such as Collagen-Polypyrrole combined with Quercetin (Col-PPy-Qur) composite. The prepared composites are characterized for their chemical functionality and morphology by the FTIR and SEM & TEM analysis, respectively. The Col-PPy-Qur composite observed electrical conductivity at 0.0653 s/cm due to the conductive Polypyrrole polymer present in the composite. The Col-PPy-Qur composite exhibits a mechanical strength of 0.1281 mPa, similar to the native human spinal cord's mechanical strength. In order to explore the regeneration potential, the viability of the composite has been tested with human astrocyte cells (HACs). The Tuj1 and GFAF marker expression was quantized by RT-PCR analysis. Increased Tuj1 and decreased GFAF expression by the Col-PPy-Qur composite indicated the potential differentiation ability of the HACs into neuron cells. The results indicated that the Col-PPy-Qur composite could have good regeneration and differentiation ability, better biocompatibility, and suitable mechanical and conductivity properties. It can act as an excellent strategy for spinal cord regeneration in the nearer future.

TiO2-Nanowired Delivery of Chinese Extract of Ginkgo biloba EGb-761 and Bilobalide BN-52021 Enhanced Neuroprotective Effects of Cerebrolysin Following Spinal Cord Injury at Cold Environment

Military personnel during combat or peacekeeping operations are exposed to extreme climates of hot or cold environments for longer durations. Spinal cord injury is quite common in military personnel following central nervous system (CNS) trauma indicating a possibility of altered pathophysiological responses at different ambient temperatures. Our previous studies show that the pathophysiology of brain injury is exacerbated in animals acclimated to cold (5 °C) or hot (30 °C) environments. In these diverse ambient temperature zones, trauma exacerbated oxidative stress generation inducing greater blood-brain barrier (BBB) permeability and cell damage. Extracts of Ginkgo biloba EGb-761 and BN-52021 treatment reduces brain pathology following heat stress. This effect is further improved following TiO₂ nanowired delivery in heat stress in animal models. Several studies indicate the role of EGb-761 in attenuating spinal cord induced neuronal damages and improved functional deficit. This is quite likely that these effects are further improved following nanowired delivery of EGb-761 and BN-52021 with cerebrolysin-a balanced composition of several neurotrophic factors and peptide fragments in spinal cord trauma. In this review, TiO₂ nanowired delivery of EGb-761 and BN-52021 with nanowired cerebrolysin is examined in a rat model of spinal cord injury at cold environment. Our results show that spinal cord injury aggravates cord pathology in cold-acclimated rats and nanowired delivery of EGb-761 and BN-52021 with cerebrolysin significantly induced superior neuroprotection, not reported earlier.

Total flavonoids of hawthorn leaves protect spinal motor neurons via promotion of autophagy after spinal cord injury

The death of spinal motor neurons (SMNs) after spinal cord injury (SCI) is a crucial cause, contributing to a permanent neurological deficit. Total flavonoids of hawthorn leaves (TFHL) have been confirmed to have potentially therapeutic for SCI. Nonetheless, the roles and mechanisms of TFHL in recovering neuromotor function and regenerating axons of SMNs have not been fully elucidated. In this study, TFHL was applied to treat rats with SCI and injured SMNs for 7 days. In vivo experiment, rats with SCI were evaluated by a BBB (Basso-Beattie-Bresnahan) score to assess their motor functional recovery. The morphology, microstructure, apoptosis, Nissl bodies, and autophagy of SMNs in spinal cord tissue were detected by Hematoxylin-eosin (HE) staining, transmission electron microscopy, TUNEL staining, Nissl staining, and immunohistochemistry respectively. In vitro experiment, the co-culture model of SMNs and astrocytes was constructed to simulate the internal environment around SMNs in the spinal cord tissue. The cell morphology, microstructure, axonal regeneration, and autophagy were observed via optical microscope, transmission electron microscopy, and immunofluorescence. The content of neurotrophic factors in the cell culture medium of the co-culture model was detected by ELISA. Moreover, the expression of axon-related and autophagy-related proteins in the spinal cord tissue and SMNs was measured by Western Blot. We demonstrated that TFHL improved the neuromotor function recovery in rats after SCI. We then found that TFHL significantly promoted injured spinal cord tissue repair, reduced apoptosis, and improved the functional status of neurons in spinal cord tissue in vivo. Meanwhile, the cell morphology, microstructure, and axonal regeneration of damaged SMNs also obviously were improved, and the secretion of neurotrophic factors was facilitated after treatment with TFHL in vitro. Further, we revealed that TFHL promoted autophagy and related protein expression in vivo and vitro. Taken together, our study suggested that TFHL might facilitate autophagy and have neuroprotective properties in SMNs to enhance the recovery of neuromotor function of rats with SCI.

Effects of Origanum vulgare and Scutellaria baicalensis on the Physiological Activity and Biochemical Parameters of the Blood in Rats on a High-Fat Diet

The pharmacological effects of medicinal plants play a primary role in the mild correction of body weight in humans and animals, reducing the accumulation of fat in their bodies during a state of obesity. Origanum vulgare L. and Scutellaria baicalensis Georgi are widely used as food additives and medicinal plants, but their comprehensive physiological evaluation in model animals in a state of obesity has not been carried out. In a 30-day laboratory experiment on male rats which had developed obesity through a hypercaloric diet, the effects of adding the dry crushed grass O. vulgare or dry crushed roots of S. baicalensis to their feed was evaluated. During the experiment, the rats fed with O. vulgare increased in body weight to only 105.5% of their initial weight, while the body weight of the control group increased to 111.5%, and that of animals fed on S. baicalensis increased to 124.0% of their initial body weight. The average daily increase in the rats’ body weight when O. vulgare was added to their diet decreased to 205 mg/day, and when S. baicalensis was added, on the contrary, it increased to 1417 mg/day, compared to 700 mg/day among the control group. Under the influence of O. vulgare, the lipid metabolism of the rats normalized: the atherogenic index decreased to 33.7%, compared with the values of the control group, due to an increase in the concentration of high-density lipoproteins from cholesterol. The concentration of triglycerides decreased, and the concentration of glucose decreased. The roots of S. baicalensis being added into the diet of rats increased the activity of alkaline phosphatase and decreased the concentration of urea. The atherogenic index also decreased (by up to 35.5% in the control group) and the concentration of high-density lipoprotein cholesterol increased, while the concentrations of triglycerides and glucose decreased. The physical activity of the rats showed a slight tendency to decrease when both O. vulgare and S. baicalensis were added to their diet. Both plant species contributed to a decrease in the emotional status of animals, which was most pronounced when the O. vulgare grass was added to the feed. The results of the study demonstrate the potential of the use of O. vulgare and S. baicalensis as herbal supplementations for the correction of hyperlipidemia and type-2 diabetes mellitus in overweight patients.

Inflammation and Oxidative Stress as Common Mechanisms of Pulmonary, Autonomic and Musculoskeletal Dysfunction after Spinal Cord Injury

Simple Summary

When a spinal cord injury occurs, the neurons that regulate our voluntary movements, those involved in environment and somatic perception and those that regulate vegetative functions are affected. Once neuronal damage is established, the cells of other tissues are also affected in their functions, altering the interaction between organs and altering the proper functioning of the organism. Multiple studies in animal models, as well as in humans, have recognized as factors involved in organ damage the imbalance between the formation of highly reactive molecules called pro-oxidants and defensive mechanisms called antioxidants. Closely associated with this phenomenon, the inflammatory response is also pathologically activated. In this narrative review, we have analyzed the information involving these pathological processes at the level of the lung, the autonomic nervous system and the skeletal musculature after spinal cord injury. Knowing the abnormal functioning mechanisms that occur after a spinal cord injury not only offers a better understanding of the organic events but also offers future possibilities for therapeutic interventions that may benefit the thousands of patients suffering this pathology.

Abstract

One of the etiopathogenic factors frequently associated with generalized organ damage after spinal cord injury corresponds to the imbalance of the redox state and inflammation, particularly of the respiratory, autonomic and musculoskeletal systems. Our goal in this review was to gain a better understanding of this phenomenon by reviewing both animal and human studies. At the respiratory level, the presence of tissue damage is notable in situations that require increased ventilation due to lower thoracic distensibility and alveolar inflammation caused by higher levels of leptin as a result of increased fatty tissue. Increased airway reactivity, due to loss of sympathetic innervation, and levels of nitric oxide in exhaled air that are similar to those seen in asthmatic patients have also been reported. In addition, the loss of autonomic control efficiency leads to an uncontrolled release of catecholamines and glucocorticoids that induce immunosuppression, as well as a predisposition to autoimmune reactions. Simultaneously, blood pressure regulation is altered with vascular damage and atherogenesis associated with oxidative damage. At the muscular level, chronically elevated levels of prooxidants and lipoperoxidation associated with myofibrillar atrophy are described, with no reduction or reversibility of this process through antioxidant supplementation.

An updated review on the versatile role of chrysin in neurological diseases: Chemistry, pharmacology, and drug delivery approaches

Neurological diseases are responsible for a large number of morbidities and mortalities in the world. Flavonoids are phytochemicals that possess various health-promoting impacts. Chrysin, a natural flavonoid isolated from diverse fruits, vegetables, and even mushrooms, has several pharmacological activities comprising antioxidant, anti-inflammatory, antiapoptotic, anticancer, and neuroprotective effects. The current study was designed to review the relationship between chrysin administration and neurological complications by discussing the feasible mechanism and signaling pathways. Herein, we mentioned the sources, pharmacological properties, chemistry, and drug delivery systems associated with chrysin pharmacotherapy. The role of chrysin was discussed in depression, anxiety, neuroinflammation, Alzheimer's disease, Parkinson's disease, Huntington's disease, epilepsy, cerebral ischemia, spinal cord injury, neuropathy, Multiple Sclerosis, and Guillain-Barré Syndrome. The findings indicate that chrysin has protective effects against neurological conditions by modulating oxidative stress, inflammation, and apoptosis in animal models. However, more studies should be done to clear the neuroprotective effects of chrysin.

Isorhamnetin promotes functional recovery in rats with spinal cord injury by abating oxidative stress and modulating M2 macrophages/microglia polarization

Spinal cord injury (SCI), mostly caused by sports injuries, falls, or traffic accidents, is a major cause of disability. The aim of current work was to investigate the therapeutic effect of isorhamnetin (ISO) on functional recovery in rats with SCI. The male adult rats were exposed to a clip-compression SCI and treated with ISO. ISO treatment improved locomotor function and reduced the loss of motor neurons in SCI rats. Treatment with ISO markedly relieved SCI-induced hypersensitivities to mechanical and thermal stimulation in rats. ISO treatment activated nuclear factor-erythroid 2-related factor 2 (Nrf2)/heme oxygenase 1 (HO-1) pathway and abated oxidative stress in injured spinal cords. ISO treatment partly suppressed microglial and glial activation and reduced expression of inflammatory cytokines including TNF-α, monocyte chemotactic protein-1 (MCP-1), and IL-1β in injured spinal cords. More importantly, ISO treatment promoted M2 macrophage activation in the injured region. lipopolysaccharide (LPS) or IL-4 was employed to stimulate macrophages/microglia into M1 or M2 phenotype in cultured BV2 cells in vitro. ISO treatment enhanced the expression of characteristic microglial anti-inflammatory polarization markers in BV2 cells. In conclusions, ISO treatment promotes functional recovery in rats with SCI by abating oxidative stress and modulating M1/M2 macrophage polarization.

Total flavonoids of hawthorn leaves promote motor function recovery via inhibition of apoptosis after spinal cord injury

Flavonoids have been reported to have therapeutic potential for spinal cord injury. Hawthorn leaves have abundant content and species of total flavonoids, and studies of the effects of the total flavonoids of hawthorn leaves on spinal cord injury have not been published in or outside China. Therefore, Sprague-Dawley rats were used to establish a spinal cord injury model by Allen’s method. Rats were intraperitoneally injected with 0.2 mL of different concentrations of total flavonoids of hawthorn leaves (5, 10, and 20 mg/kg) after spinal cord injury. Injections were administered once every 6 hours, three times a day, for 14 days. After treatment with various concentrations of total flavonoids of hawthorn leaves, the Basso, Beattie, and Bresnahan scores and histological staining indicated decreases in the lesion cavity and number of apoptotic cells of the injured spinal cord tissue; the morphological arrangement of the myelin sheath and nerve cells tended to be regular; and the Nissl bodies in neurons increased. The Basso, Beattie, and Bresnahan scores of treated spinal cord injury rats were increased. Western blot assays showed that the expression levels of pro-apoptotic Bax and cleaved caspase-3 were decreased, but the expression level of the anti-apoptotic Bcl-2 protein was increased. The improvement of the above physiological indicators showed a dose-dependent relationship with the concentration of total flavonoids of hawthorn leaves. The above findings confirm that total flavonoids of hawthorn leaves can reduce apoptosis and exert neuroprotective effects to promote the recovery of the motor function of rats with spinal cord injury. This study was approved by the Ethics Committee of the Guangxi Medical University of China (approval No. 201810042) in October 2018.

Targeting apoptosis and autophagy following spinal cord injury: Therapeutic approaches to polyphenols and candidate phytochemicals

Spinal cord injury (SCI) is a neurological disorder associated with the loss of sensory and motor function. Understanding the precise dysregulated signaling pathways, especially apoptosis and autophagy following SCI, is of vital importance in developing innovative therapeutic targets and treatments. The present study lies in the fact that it reveals the precise dysregulated signaling mediators of apoptotic and autophagic pathways following SCI and also examines the effects of polyphenols and other candidate phytochemicals. It provides new insights to develop new treatments for post-SCI complications. Accordingly, a comprehensive review was conducted using electronic databases including, Scopus, Web of Science, PubMed, and Medline, along with the authors' expertise in apoptosis and autophagy as well as their knowledge about the effects of polyphenols and other phytochemicals on SCI pathogenesis. The primary mechanical injury to spinal cord is followed by a secondary cascade of apoptosis and autophagy that play critical roles during SCI. In terms of pharmacological mechanisms, caspases, Bax/Bcl-2, TNF-α, and JAK/STAT in apoptosis along with LC3 and Beclin-1 in autophagy have shown a close interconnection with the inflammatory pathways mainly glutamatergic, PI3K/Akt/mTOR, ERK/MAPK, and other cross-linked mediators. Besides, apoptotic pathways have been shown to regulate autophagy mediators and vice versa. Prevailing evidence has highlighted the importance of modulating these signaling mediators/pathways by polyphenols and other candidate phytochemicals post-SCI. The present review provides dysregulated signaling mediators and therapeutic targets of apoptotic and autophagic pathways following SCI, focusing on the modulatory effects of polyphenols and other potential phytochemical candidates.

Spinal Cord Injury Scarring and Inflammation: Therapies Targeting Glial and Inflammatory Responses

Deficits in neuronal function are a hallmark of spinal cord injury (SCI) and therapeutic efforts are often focused on central nervous system (CNS) axon regeneration. However, secondary injury responses by astrocytes, microglia, pericytes, endothelial cells, Schwann cells, fibroblasts, meningeal cells, and other glia not only potentiate SCI damage but also facilitate endogenous repair. Due to their profound impact on the progression of SCI, glial cells and modification of the glial scar are focuses of SCI therapeutic research. Within and around the glial scar, cells deposit extracellular matrix (ECM) proteins that affect axon growth such as chondroitin sulfate proteoglycans (CSPGs), laminin, collagen, and fibronectin. This dense deposition of material, i.e., the fibrotic scar, is another barrier to endogenous repair and is a target of SCI therapies. Infiltrating neutrophils and monocytes are recruited to the injury site through glial chemokine and cytokine release and subsequent upregulation of chemotactic cellular adhesion molecules and selectins on endothelial cells. These peripheral immune cells, along with endogenous microglia, drive a robust inflammatory response to injury with heterogeneous reparative and pathological properties and are targeted for therapeutic modification. Here, we review the role of glial and inflammatory cells after SCI and the therapeutic strategies that aim to replace, dampen, or alter their activity to modulate SCI scarring and inflammation and improve injury outcomes.