A review on the neuroprotective effects of hyperbaric oxygen therapy

'Comprehensive review of emerging drug targets in traumatic brain injury (TBI): challenges and future scope

Traumatic brain injury (TBI) is a complex brain problem that causes significant morbidity and mortality among people of all age groups. The complex pathophysiology, varied symptoms, and inadequate treatment further precipitate the problem. Further, TBI produces several psychiatric problems and other related complications in post-TBI survival patients, which are often treated symptomatically or inadequately. Several approaches, including neuroprotective agents targeting several pathways of oxidative stress, neuroinflammation, cytokines, immune system GABA, glutamatergic, microglia, and astrocytes, are being tried by researchers to develop effective treatments or magic bullets to manage the condition effectively. The problem of TBI is therefore treated as a challenge among pharmaceutical scientists or researchers to develop drugs for the effective management of this problem. The goal of the present comprehensive review is to provide an overview of the several pharmacological targets, processes, and cellular pathways that researchers are focusing on, along with an update on their current state.

Analysis of the efficacy of hyperbaric oxygen therapy for disorders of consciousness: A retrospective cohort study

OBJECTIVE

To analyze the efficacy and associated factors affecting the prognosis in patients with disturbance of consciousness after hyperbaric oxygen (HBO) treatment.

METHODS

A retrospective study was carried out on patients with disorders of consciousness (DOC) receiving HBO treatment from January to January 2022 in the Second Department of Rehabilitation Medicine of the Second Hospital of Hebei Medical University, China.

RESULTS

HBO therapy improved the Glasgow Coma Scale (GCS) and Chinese Nanjing Persistent Vegetative State Scale (CNPVSS), as well as the clinical efficacy in patients with DOC. The comparison of GCS and CNPVSS scores in patients with DOC before and after HBO treatment was all statistically significant, with 325 patients (67.1%) showing effective results and 159 patients (32.9%) having unchanged outcomes. Univariate analysis indicated that there were statistically significant differences in age, HBO intervention time, HBO treatment times, pre-treatment GCS score, and etiology and underlying diseases between the good and poor prognoses groups. Multivariate regression analysis showed that HBO intervention time ≤7 days, HBO treatment ＞ times, high GCS score before HBO treatment, and brain trauma were independent influencing factors in achieving a good prognosis for patients with DOC. Low pre-treatment GCS scores were an independent risk factor for a poor prognosis in patients with brain trauma while being male, late HBO intervention time, fewer HBO treatment times, and low pre-treatment GCS scores were independent risk factors for a poor prognosis in patients with DOC after a stroke. Being ≥50 years of age, late HBO intervention time, and low pre-treatment GCS scores were independent risk factors for a poor prognosis in patients with DOC after hypoxic-ischaemic encephalopathy.

CONCLUSION

HBO therapy can improve the GCS, CNPVSS scores and clinical efficacy in patients with DOC, and the timing of HBO intervention ≤7 days, times of HBO treatment, high pre-treatment GCS score, and brain trauma were the independent influencing factors of good prognosis in patients with DOC.

Reactive Oxygen Species (ROS)-Mediated Antibacterial Oxidative Therapies: Available Methods to Generate ROS and a Novel Option Proposal

The increasing emergence of multidrug-resistant (MDR) pathogens causes difficult-to-treat infections with long-term hospitalizations and a high incidence of death, thus representing a global public health problem. To manage MDR bacteria bugs, new antimicrobial strategies are necessary, and their introduction in practice is a daily challenge for scientists in the field. An extensively studied approach to treating MDR infections consists of inducing high levels of reactive oxygen species (ROS) by several methods. Although further clinical investigations are mandatory on the possible toxic effects of ROS on mammalian cells, clinical evaluations are extremely promising, and their topical use to treat infected wounds and ulcers, also in presence of biofilm, is already clinically approved. Biochar (BC) is a carbonaceous material obtained by pyrolysis of different vegetable and animal biomass feedstocks at 200-1000 °C in the limited presence of O2. Recently, it has been demonstrated that BC's capability of removing organic and inorganic xenobiotics is mainly due to the presence of persistent free radicals (PFRs), which can activate oxygen, H2O2, or persulfate in the presence or absence of transition metals by electron transfer, thus generating ROS, which in turn degrade pollutants by advanced oxidation processes (AOPs). In this context, the antibacterial effects of BC-containing PFRs have been demonstrated by some authors against Escherichia coli and Staphylococcus aureus, thus giving birth to our idea of the possible use of BC-derived PFRs as a novel method capable of inducing ROS generation for antimicrobial oxidative therapy. Here, the general aspects concerning ROS physiological and pathological production and regulation and the mechanism by which they could exert antimicrobial effects have been reviewed. The methods currently adopted to induce ROS production for antimicrobial oxidative therapy have been discussed. Finally, for the first time, BC-related PFRs have been proposed as a new source of ROS for antimicrobial therapy via AOPs.

Treating Alzheimer's disease using nanoparticle-mediated drug delivery strategies/systems

The administration of promising medications for the treatment of neurodegenerative disorders (NDDs), such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS) is significantly hampered by the blood-brain barrier (BBB). Nanotechnology has recently come to light as a viable strategy for overcoming this obstacle and improving drug delivery to the brain. With a focus on current developments and prospects, this review article examines the use of nanoparticles to overcome the BBB constraints to improve drug therapy for AD The potential for several nanoparticle-based approaches, such as those utilizing lipid-based, polymeric, and inorganic nanoparticles, to enhance drug transport across the BBB are highlighted. To shed insight on their involvement in aiding effective drug transport to the brain, methods of nanoparticle-mediated drug delivery, such as surface modifications, functionalization, and particular targeting ligands, are also investigated. The article also discusses the most recent findings on innovative medication formulations encapsulated within nanoparticles and the therapeutic effects they have shown in both preclinical and clinical testing. This sector has difficulties and restrictions, such as the need for increased safety, scalability, and translation to clinical applications. However, the major emphasis of this review aims to provide insight and contribute to the knowledge of how nanotechnology can potentially revolutionize the worldwide treatment of NDDs, particularly AD, to enhance clinical outcomes.

Hyperbaric Oxygen Therapy Attenuated the Motor Coordination and Cognitive Impairment of Polyglutamine Spinocerebellar Ataxia SCA17 Mice

Spinocerebellar ataxias (SCAs) are a large and diverse group of autosomal-dominant neurodegenerative diseases. No drugs have been approved for these relentlessly progressive and fatal SCAs. Our previous studies indicate that oxidative stress, neuroinflammation, and neuronal apoptosis are elevated in the SCA17 mice, which are the main therapeutic targets of hyperbaric oxygen treatment (HBOT). HBOT is considered to be an alternative and less invasive therapy for SCAs. In this study, we evaluated the HBOT (2.2 ATA for 14 days) effect and the persistence for the management of SCA17 mice and their wild-type littermates. We found HBOT attenuated the motor coordination and cognitive impairment of SCA17 mice and which persisted for about 1 month after the treatment. The results of several biochemistry and liver/kidney hematoxylin and eosin staining show the HBOT condition has no obvious toxicity in the mice. Immunostaining analyses show that the neuroprotective effect of HBOT could be through the promotion of BDNF production and the amelioration of neuroinflammation. Surprisingly, HBOT executes different effects on the male and female SCA17 mice, including the reduction of neuroinflammation and activation of CaMKII and ERK. This study suggests HBOT is a potential alternative therapeutic treatment for SCA17. Accumulated findings have revealed the similarity in disease pathomechanisms and possible therapeutic strategies in polyQ diseases; therefore, HBOT could be an optional treatment as well as the other polyQ diseases.

Exercise-Induced Reduction of IGF1R Sumoylation Attenuates Neuroinflammation in APP/PS1 Transgenic Mice

INTRODUCTION

Alzheimer's Disease (AD), a progressive neurodegenerative disorder, is marked by cognitive deterioration and heightened neuroinflammation. The influence of Insulin-like Growth Factor 1 Receptor (IGF1R) and its post-translational modifications, especially sumoylation, is crucial in understanding the progression of AD and exploring novel therapeutic avenues.

OBJECTIVES

This study investigates the impact of exercise on the sumoylation of IGF1R and its role in ameliorating AD symptoms in APP/PS1 mice, with a specific focus on neuroinflammation and innovative therapeutic strategies.

METHODS

APP/PS1 mice were subjected to a regimen of moderate-intensity exercise. The investigation encompassed assessments of cognitive functions, alterations in hippocampal protein expressions, neuroinflammatory markers, and the effects of exercise on IGF1R and SUMO1 nuclear translocation. Additionally, the study evaluated the efficacy of KPT-330, a nuclear export inhibitor, as an alternative to exercise.

RESULTS

Exercise notably enhanced cognitive functions in AD mice, possibly through modulations in hippocampal proteins, including Bcl-2 and BACE1. A decrease in neuroinflammatory markers such as IL-1β, IL-6, and TNF-α was observed, indicative of reduced neuroinflammation. Exercise modulated the nuclear translocation of SUMO1 and IGF1R in the hippocampus, thereby facilitating neuronal regeneration. Mutant IGF1R (MT IGF1R), lacking SUMO1 modification sites, showed reduced SUMOylation, leading to diminished expression of pro-inflammatory cytokines and apoptosis. KPT-330 impeded the formation of the IGF1R/RanBP2/SUMO1 complex, thereby limiting IGF1R nuclear translocation, inflammation, and neuronal apoptosis, while enhancing cognitive functions and neuron proliferation.

CONCLUSION

Moderate-intensity exercise effectively mitigates AD symptoms in mice, primarily by diminishing neuroinflammation, through the reduction of IGF1R Sumoylation. KPT-330, as a potential alternative to physical exercise, enhances the neuroprotective role of IGF1R by inhibiting SUMOylation through targeting XPO1, presenting a promising therapeutic strategy for AD.

The Role of Oxidative Stress in Trisomy 21 Phenotype

Extensive research has been conducted to gain a deeper understanding of the deregulated metabolic pathways in the development of trisomy 21 (T21) or Down syndrome. This research has shed light on the hypothesis that oxidative stress plays a significant role in the manifestation of the T21 phenotype. Although in vivo studies have shown promising results in mitigating the detrimental effects of oxidative stress, there is currently a lack of introduced antioxidant treatment options targeting cognitive impairments associated with T21. To address this gap, a comprehensive literature review was conducted to provide an updated overview of the involvement of oxidative stress in T21. The review aimed to summarize the insights into the pathogenesis of the Down syndrome phenotype and present the findings of recent innovative research that focuses on improving cognitive function in T21 through various antioxidant interventions. By examining the existing literature, this research seeks to provide a holistic understanding of the role oxidative stress plays in the development of T21 and to explore novel approaches that target multiple aspects of antioxidant intervention to improve cognitive function in individuals with Down syndrome. The guides -base systematic review process (Hutton et al. 2015).

The 2023 Turkey Earthquake: Management of 627 Pediatric Musculoskeletal Injuries in the First Month

(1) Background: On 6February 2023, two consecutive earthquakes hit Kahramanmaraş and surrounding ten cities, killing over 50,000 people. We aimed to reveal the treatment process of pediatric patients admitted to Adana City Hospital (ACH) in the first month after the earthquake. (2) Methods: Demographic data of the patients, time of presentation to the emergency department, injury locations, treatment procedures, and patient file information were recorded retrospectively and evaluated statistically. (3) Results: There were 1246 patients under the age of 18. A total of 560 patients were hospitalized in the orthopedic clinic; 42% were admitted in the first 24 h and 58% in the first three days. Of these children, 69 (12%) were referred, 52 (10%) were transferred to other departments within the hospital, and 421 (75.2%) were discharged in stable condition. The number of patients with large bone fractures was 77 (34 open fractures). Fasciotomy surgery was performed on 131 patients, 78 of whom had bilateral procedures. Of the 31 patients who underwent amputation, 17 (55%) were performed within the first 24 h and 28 (90%) within the first week. (4) Conclusions: Almost all injured children are admitted to the hospital during the first few days after an earthquake. The management of earthquake injuries in pediatric patients requires specialized care and immediate attention during the treatment process.

Hyperbaric Oxygen Therapy and Tissue Regeneration: A Literature Survey

By addressing the mechanisms involved in transcription, signaling, stress reaction, apoptosis and cell-death, cellular structure and cell-to-cell contacts, adhesion, migration as well as inflammation; HBO upregulates processes involved in repair while mechanisms perpetuating tissue damage are downregulated. Many experimental and clinical studies, respectively, cover wound healing, regeneration of neural tissue, of bone and cartilage, muscle, and cardiac tissue as well as intestinal barrier function. Following acute injury or in chronic healing problems HBO modulates proteins or molecules involved in inflammation, apoptosis, cell growth, neuro- and angiogenesis, scaffolding, perfusion, vascularization, and stem-cell mobilization, initiating repair by a variety of mechanisms, some of them based on the modulation of micro-RNAs. HBO affects the oxidative stress response via nuclear factor erythroid 2-related factor 2 (Nrf2) or c-Jun N-terminal peptide and downregulates inflammation by the modulation of high-mobility group protein B1 (HMGB-1), toll-like receptor 4 and 2 (TLR-4, TLR-2), nuclear factor kappa-B (NFκB), hypoxia-inducible factor (HIF-1α) and nitric oxide (NO•). HBO enhances stem-cell homeostasis via Wnt glycoproteins and mammalian target of rapamycin (mTOR) and improves cell repair, growth, and differentiation via the two latter but also by modulation of extracellular-signal regulated kinases (ERK) and the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) pathway. The HBO-induced downregulation of matrix metalloproteinases-2 and 9 (MMP-2/-9), rho-associated protein kinase (ROCK) and integrins improve healing by tissue remodeling. Interestingly, the action of HBO on single effector proteins or molecules may involve both up- or downregulation, respectively, depending on their initial level. This probably mirrors a generally stabilizing potential of HBO that tends to restore the physiological balance rather than enhancing or counteracting single mechanisms.

The role of hyperbaric oxygen therapy in the management of perioperative peripheral nerve injury: a scoping review of the literature

Background/importance

Peripheral nerve injury is an uncommon but potentially catastrophic complication of anesthesia and surgery, for which there are limited effective treatment options. Hyperbaric oxygen therapy is a unique medical intervention which improves tissue oxygen delivery and reduces ischemia via exposure to oxygen at supra-atmospheric partial pressures. While the application of hyperbaric oxygen therapy has been evidenced for other medical conditions involving relative tissue ischemia, its role in the management of peripheral nerve injury remains unclear.

Objective

This scoping review seeks to characterize rehabilitative outcomes when hyperbaric oxygen therapy is applied as an adjunct therapy in the treatment of perioperative peripheral nerve injury.

Evidence review

The review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines for scoping reviews, using a systematic screening and extraction process. The search included articles published from database inception until June 11, 2022, which reported clinical outcomes (in both human and non-human models) of peripheral nerve injury treated with hyperbaric oxygen therapy.

Findings

A total of 51 studies were included in the narrative synthesis. These consisted of animal (40) and human studies (11) treating peripheral nerve injury due to various physiological insults. Hyperbaric oxygen therapy protocols were highly heterogenous and applied at both early and late intervals relative to the time of peripheral nerve injury. Overall, hyperbaric oxygen therapy was reported as beneficial in 88% (45/51) of included studies (82% of human studies and 90% of animal studies), improving nerve regeneration and/or time to recovery with no reported major adverse events.

Conclusions

Existing data suggest that hyperbaric oxygen therapy is a promising intervention in the management of perioperative peripheral nerve injury, in which tissue ischemia is the most common underlying mechanism of injury, neurological deficits are severe, and treatment options are sparse. This positive signal should be further investigated in prospective randomized clinical trials.

A Case Series of 39 United States Veterans with Mild Traumatic Brain Injury Treated with Hyperbaric Oxygen Therapy

Importance: The Defense and Veterans Brain Injury Center reported 358,088 mild traumatic brain injury (mTBI) among U.S. service members worldwide between the years 2000 and 2020. Veterans with mTBI have higher rates of Post-Traumatic Stress Disorder (PTSD), depressive disorder, substance use disorder, anxiety disorder, and suicide than their healthy counterparts. Currently, there is no effective treatment for mTBI. Objective: To assess the efficacy of hyperbaric oxygen therapy (HBOT) as a treatment option for mTBI. Design, Setting, Participants: This is a case series of 39 U.S. Veterans diagnosed with mTBI and treated with HBOT. Of these participants, 36 were men and 3 women, and their ages ranged between 28 and 69. The treatment was administered by The 22 Project (a veteran-centered nonprofit organization) using monoplace hyperbaric chambers located in Delray Beach, Florida. Neuroimaging using Single Photon Emission Computer Tomography (SPECT) brain scans performed pre- and post-HBOT were made available for secondary analysis. Nilearn Python Library was utilized to visualize the corresponding neuroimaging data. A two-sided paired t-test in R was used to compare the pre- and post-treatment results. Intervention: A full treatment of HBOT involved 40 sessions. Each session consisted of the administration of 100% oxygen at 1.5 atmospheres for 90 min, twice a day, for 20 days, Mondays to Fridays only. Main Outcome and Measure: Perfusion in the brain’s Brodmann Areas (BA) comparing pre- and post-HBOT using NeuroGam software analysis from brain SPECT scan neuroimaging and multi-symptom self-reports. Results: A comparison between the pre- and post-HBOT brain scans showed significant improvement in the brain perfusion, and the difference was statistically significant (p < 0.001). Separately, participants reported reduced pain, improved mood, and better sleep, an outcome that translated into an average of about 46.6% improvement in the measured symptoms. Conclusions and Relevance: This series demonstrated that HBOT could be a useful treatment for mTBI in U.S. veterans. The participants in the study showed marked improvement in both brain perfusion measured on SPECT scan imaging and measured mTBI symptoms. This is the first study to use brain SPECT scans with quantitative numerical measurements to demonstrate improvement in brain perfusion in veterans with mild TBI treated with HBOT and measured mTBI symptoms. Future research studies are currently being done to validate these important findings.

Hyperbaric Oxygen Therapy Alleviates the Autoimmune Encephalomyelitis via the Reduction of IL-17a and GM-Csf Production of Autoreactive T Cells as Well as Boosting the Immunosuppressive IL-10 in the Central Nervous System Tissue Lesions

Multiple sclerosis (MS) is a chronic autoimmune disease mainly caused by autoreactive T cells, followed by neuronal demyelination and disabling paralysis. Hyperbaric oxygen therapy (HBOT) is usually an adjunct to therapy for the treatment of neurological disorders. However, it remains still controversial whether HBOT is an effective option for the treatment of MS. Experimental autoimmune encephalomyelitis (EAE) is a well-studied mouse model investigated for the MS pathogenesis and the efficacy of the therapeutic intervention. Both encephalitogenic Th1 and Th17 are pivotal T cell subsets immunopathogenically producing several disease-initiating/modifying cytokines in the central nervous system (CNS) lesions to further exacerbate/ameliorate the progression of EAE or MS. However, it remains unclear whether HBOT modulates the context of T helper cell subsets in CNS lesions. We employed EAE in the presence of HBOT to assess whether disease amelioration is attributed to alterations of CNS-infiltrating T cell subsets. Our results demonstrated that semi-therapeutic HBOT significantly alleviated the progression of EAE, at least, via the suppression of Th17 response, the downregulation of CD4 T helper cells expressing GM-CSF or TNF-α, and the boosting of immunomodulatory IL-4 or IL-10-expressed CD4 T cells in the CNS lesions. Conclusively, HBOT attenuated EAE through the modulation of T cell responses in an earlier stage.