Effects of α-tocopherol and ascorbic acid in the severity and management of traumatic brain injury in albino rats

Nutritional Support Following Traumatic Brain Injury: A Comprehensive Review

Traumatic brain injury (TBI) can contribute to extensive dysbiosis of the gastrointestinal system, leading to worsened outcomes. The importance of nutrition in recovery is underappreciated but highly important. In this focused review, we discuss the timing of nutritional interventions with supporting data. We highlight routes of administration that are important given the extent of injury often seen in TBI. The increased energy demands can be met through these approaches. Furthermore, patients need increased vitamins, minerals, and supplements. These interventions are constantly being refined. The current standards are reviewed with an emphasis on evidence-based practices.

Ascorbic acid as antioxidant

Ascorbic acid, as one of the basic exogenous vitamins, is known for its tremendous antioxidant properties. This review has been prepared to show not only the importance of ascorbic acid as a free radical scavenger, but also to summarize its antioxidant action based on other mechanisms, including activation of intracellular antioxidant systems. Ascorbic acid interacts with small molecule antioxidants, including tocopherol, glutathione and thioredoxin, but also can stimulate the biosynthesis and activation of antioxidant enzymes, such as superoxide dismutase, catalase or glutathione peroxidase. Moreover, ascorbic acid promotes the activity of several transcription factors (Nrf2, Ref-1, AP-1), which enables the expression of genes encoding antioxidant proteins. Additionally, it supports the action of other exogenous antioxidants, mainly polyphenols. In this connection, both DNA, protein and lipids are protected against oxidation. Although ascorbic acid has strong antioxidant properties, it can also have pro-oxidant effects in the presence of free transition metals. However, its role in prevention of DNA mutation and cellular apoptosis, especially in relation to cancer cells is controversial.

The effect of Vitamins C and E on clinical outcomes of patients with severe traumatic brain injury: A propensity score matching study

Background

The aim of this study was to assess the effect of Vitamins C and E on mortality, intensive care unit (ICU) length of stay, and Glasgow Outcome Scale-Extended (GOS-E) score of traumatic brain injury (TBI) patients.

Methods

Using data from records of patients in a retrospective cohort study, we included 1321 TBI patients, 269 treated and 1052 untreated, aged over 18 years with information on exposure (i.e., Vitamins C and E) and confounders. Age, Glasgow Coma Scale, pupil status, Rotterdam classification, blood sugar, blood pressure, international normalized ratio, and comorbidity of patients were considered as the confounding factors. Endpoints were GOS-E on follow-up, mortality, and ICU length of stay. Propensity score matching was performed to adjust the confounders.

Results

Based on the average treatment effect estimates, the use of Vitamins C and E reduced the risk of mortality (risk difference [RD]: -0.07; 95% confidence interval [CI]: -0.14--0.003) and reduced the length of ICU stay (RD -1.77 95% CI:-3.71-0.16). Furthermore, our results showed that GOS-E was improved significantly (RD: 0.09, 95% CI : 0.03-0.16).

Conclusion

Our study suggests that using Vitamins C and E could decrease mortality and length of ICU stay and improve the GOS-E score and functions of the patients with severe TBI. As they are safe and inexpensive medications, they can be used in routine practice in ICUs to improve the outcomes of TBI patients.

Serum vitamin E level and functional prognosis after traumatic brain injury with intracranial injury: A multicenter prospective study

Background

Traumatic brain injury (TBI) is a major public health problem with high mortality and disability. Vitamin E, one of the antioxidants for treatment of TBI, has not been sufficiently evaluated for predicting prognosis of TBI. This study aimed to evaluate the prognostic value of vitamin E on functional outcomes of TBI patients with intracranial injury.

Methods

A multi-center prospective cohort study was conducted in five university hospitals between 2018 and 2020. Adult TBI patients who visited the emergency department (ED) with intracranial hemorrhage or diffuse axonal injury confirmed by radiological examination were eligible. Serum vitamin E levels (mg/dL) were categorized into 4 groups: low (0.0–5.4), low-normal (5.5–10.9), high-normal (11.0–16.9), and high (17.0–). Study outcomes were set as 1- and 6-month disability (Glasgow outcome scale (GOS) 1–4). Multilevel logistic regression analysis was conducted to calculate the adjusted odds ratios (AORs) of vitamin E for related outcomes.

Results

Among 550 eligible TBI patients with intracranial injury, the median (IQR) of serum vitamin E was 10.0 (8.0–12.3) mg/dL; 204/550 (37.1%) had 1-month disability and 197/544 (36.1%) had 6-month disability of GOS 1–4. Compared with the high-normal group, the odds of 1-month disability and 6-month disability increased in the low and low-normal group (AORs (95% CIs): 3.66 (1.62–8.27) and 2.60 (1.15–5.85) for the low group and 1.63 (1.08–2.48) and 1.60 (1.04–2.43) for the low-normal group, respectively).

Conclusion

Low serum vitamin E level was associated with poor prognosis at 1 and 6 months after TBI with intracranial injury.

Antioxidative and Anti-Inflammatory Activity of Ascorbic Acid

Ascorbic acid, as a one of the basic exogenous vitamins, occurs in the body in the form of ascorbate, known for its strong antioxidant and anti-inflammatory properties. The presented review shows not only the importance of ascorbate as a free radical scavenger but also summarizes its antioxidant action based on other mechanisms, including the activation of intracellular antioxidant systems and its effect on the NFκB/TNFα pathway and apoptosis. Ascorbate interacts with small-molecule antioxidants, including tocopherol, glutathione, and thioredoxin; it can also stimulate biosynthesis and the activation of antioxidant enzymes, such as superoxide dismutase, catalase, or glutathione peroxidase. Moreover, ascorbate promotes the activity of transcription factors (Nrf2, Ref-1, AP-1), which enables the expression of genes encoding antioxidant proteins. Additionally, it supports the action of other exogenous antioxidants, mainly polyphenols. In this regard, both DNA, proteins, and lipids are protected against oxidation, leading to an inflammatory reaction and even cell death. Although ascorbate has strong antioxidant properties, it can also have pro-oxidant effects in the presence of free transition metals. However, its role in the prevention of DNA mutation, inflammation, and cell apoptosis, especially in relation to cancer cells, is controversial.

Neuro-Inflammation Modulation and Post-Traumatic Brain Injury Lesions: From Bench to Bed-Side

Head trauma is the most common cause of disability in young adults. Known as a silent epidemic, it can cause a mosaic of symptoms, whether neurological (sensory-motor deficits), psychiatric (depressive and anxiety symptoms), or somatic (vertigo, tinnitus, phosphenes). Furthermore, cranial trauma (CT) in children presents several particularities in terms of epidemiology, mechanism, and physiopathology-notably linked to the attack of an immature organ. As in adults, head trauma in children can have lifelong repercussions and can cause social and family isolation, difficulties at school, and, later, socio-professional adversity. Improving management of the pre-hospital and rehabilitation course of these patients reduces secondary morbidity and mortality, but often not without long-term disability. One hypothesized contributor to this process is chronic neuroinflammation, which could accompany primary lesions and facilitate their development into tertiary lesions. Neuroinflammation is a complex process involving different actors such as glial cells (astrocytes, microglia, oligodendrocytes), the permeability of the blood-brain barrier, excitotoxicity, production of oxygen derivatives, cytokine release, tissue damage, and neuronal death. Several studies have investigated the effect of various treatments on the neuroinflammatory response in traumatic brain injury in vitro and in animal and human models. The aim of this review is to examine the various anti-inflammatory therapies that have been implemented.

Oxidative stress and mitochondrial dysfunction following traumatic brain injury: From mechanistic view to targeted therapeutic opportunities

Traumatic brain injury (TBI) is one of the most prevalent causes of permanent physical and cognitive disabilities. TBI pathology results from primary insults and a multi-mechanistic biochemical process, termed as secondary brain injury. Currently, there are no pharmacological agents for definitive treatment of patients with TBI. This article is presented with the purpose of reviewing molecular mechanisms of TBI pathology, as well as potential strategies and agents against pathological pathways. In this review article, materials were obtained by searching PubMed, Scopus, Elsevier, Web of Science, and Google Scholar. This search was considered without time limitation. Evidence indicates that oxidative stress and mitochondrial dysfunction are two key mediators of the secondary injury cascade in TBI pathology. TBI-induced oxidative damage results in the structural and functional impairments of cellular and subcellular components, such as mitochondria. Impairments of mitochondrial electron transfer chain and mitochondrial membrane potential result in a vicious cycle of free radical formation and cell apoptosis. The results of some preclinical and clinical studies, evaluating mitochondria-targeted therapies, such as mitochondria-targeted antioxidants and compounds with pleiotropic effects after TBI, are promising. As a proposed strategy in recent years, mitochondria-targeted multipotential therapy is a new hope, waiting to be confirmed. Moreover, based on the available findings, biologics, such as stem cell-based therapy and transplantation of mitochondria are novel potential strategies for the treatment of TBI; however, more studies are needed to clearly confirm the safety and efficacy of these strategies.

Role of Vitamin E in Neonatal Neuroprotection: A Comprehensive Narrative Review

Vitamin E (Vit E) is an essential lipophilic antioxidant and anti-inflammatory agent that has potential as a neuroprotectant in newborn infants with brain injury. Vit E has shown promise in many in vitro studies, but success in translation to in vivo animal studies and the clinical setting has been mixed, with concern of adverse effects at high intravenous doses in preterm infants. However, a recent rise in knowledge of the beneficial effects of fat emulsions containing higher levels of Vit E, along with associated improved outcomes in some neonatal co-morbidities, has led many to reconsider Vit E administration as a potential therapeutic modality to improve neurological outcomes in the setting of neonatal brain injury. This narrative review discusses Vit E's structure, mechanism(s) of action, evidence in animal models, and association with health outcomes in neonates, including both dietary and supplemental Vit E and their bioavailability and pharmacokinetics as it relates to the brain. Lastly, long-term neurodevelopmental outcomes along with gaps in current knowledge are critiqued, which to date suggests that additional translational studies in larger animal models and assessment of safety profiles of different routes and doses of administration should be explored prior to large clinical trials. Importantly, a greater understanding of the brain region(s) and cell type(s) affected by Vit E may help to target the use of Vit E as a beneficial neuroprotective agent to specific populations or types of injury seen in newborns.

An update on pathophysiology and treatment of sports-mediated brain injury

Traumatic brain injury (TBI) is a neurological disorder which represents a major health issue worldwide. It causes mortality and disability among all group ages, caused by external force, sports-related events or violence and road traffic accidents. In the USA, approximately one-third people die annually due to injury and 1.7 million people suffer from traumatic brain injury. Every year in India around 1.6 million individuals suffer from sustain brain injury with 200,000 deaths and approximately one million person needed recovery treatment at any stage of time. Sports-related head impact and trauma has become an extremely controversial public health and medico-legal problem that accounts for 20% of all brain injury (including concussion). It is difficult to reverse the primary injury but the secondary injury can be minimized by using proper pharmacological intervention during the initial hours of injury. This article highlights the pathophysiology and types of TBI along with treatment therapies. Till date, there is no single medication that can decrease the progression of the disease so that symptomatic treatment is given to the patient by determining proper pathology. Recently various herbal medicine therapies and traditional supplements have been developed for TBI. Nutritional supplementation and nutraceuticals have exposed potential in the treatment of TBI when used before and after TBI. The compiled data will enable the readers to know the pathophysiology as well as the allopathic and natural remedies to treat the TBI.

Sports Related Brain Injury and Neurodegeneration in Athletes

Sports deserve a special place in human life to impart healthy and refreshing wellbeing. However, sports activities, especially contact sports, renders athlete vulnerable to brain injuries. Athletes participating in a contact sport like boxing, rugby, American football, wrestling, and basketball are exposed to traumatic brain injuries (TBI) or concussions. The acute and chronic nature of these heterogeneous injuries provides a spectrum of dysfunctions that alters the neuronal, musculoskeletal, and behavioral responses of an athlete. Many sports-related brain injuries go unreported, but these head impacts trigger neurometabolic disruptions that contribute to long-term neuronal impairment. The pathophysiology of post-concussion and its underlying mechanisms are undergoing intense research. It also shed light on chronic disorders like Parkinson's disease, Alzheimer's disease, and dementia. In this review, we examined post-concussion neurobehavioral changes, tools for early detection of signs, and their impact on the athlete. Further, we discussed the role of nutritional supplements in ameliorating neuropsychiatric diseases in athletes.

Neuroprotective Properties of Vitamin C: A Scoping Review of Pre-Clinical and Clinical Studies

There is a need for novel neuroprotective therapies. We aimed to review the evidence for exogenous vitamin C as a neuroprotective agent. MEDLINE, Embase, and Cochrane library databases were searched from inception to May 2020. Pre-clinical and clinical reports evaluating vitamin C for acute neurological injury were included. Twenty-two pre-clinical and 11 clinical studies were eligible for inclusion. Pre-clinical studies included models of traumatic and hypoxic brain injury, subarachnoid and intracerebral hemorrhage, and ischemic stroke. The median [IQR] maximum daily dose of vitamin C in animal studies was 120 [50-500] mg/kg. Twenty-one animal studies reported improvements in biomarkers, functional outcome, or both. Clinical studies included single reports in neonatal hypoxic encephalopathy, traumatic brain injury, and subarachnoid hemorrhage and eight studies in ischemic stroke. The median maximum daily dose of vitamin C was 750 [500-1000] mg, or ∼10 mg/kg for an average-size adult male. Apart from one case series of intracisternal vitamin C administration in subarachnoid hemorrhage, clinical studies reported no patient-centered benefit. Although pre-clinical trials suggest that exogenous vitamin C improves biomarkers of neuroprotection, functional outcome, and mortality, these results have not translated to humans. However, clinical trials used approximately one tenth of the vitamin C dose of animal studies.

An Overview and Therapeutic Promise of Nutraceuticals against Sports-Related Brain Injury

Sports-related traumatic brain injury (TBI) is one of the common neurological maladies experienced by athletes. Earlier the term 'punch drunk syndrome' was used in the case TBI of boxers and now this term is replaced by chronic traumatic encephalopathy (CTE). Sports-related brain injury can either be short term or long term. A common instance of brain injury encompasses subdural hematoma, concussion, cognitive dysfunction, amnesia, headache, vision issue, axonopathy, or even death if remain undiagnosed or untreated. Further, chronic TBI may lead to pathogenesis of neuroinflammation and neurodegeneration via tauopathy, formation of neurofibrillary tangles, and damage to the blood-brain barrier, microglial, and astrocyte activation. Thus, altered pathological, neurochemical, and neurometabolic attributes lead to the modulation of multiple signaling pathways and cause neurological dysfunction. Available pharmaceutical interventions are based on one drug one target hypothesis and thereby unable to cover altered multiple signaling pathways. However, in recent time's pharmacological intervention of nutrients and nutraceuticals have been explored as they exert a multifactorial mode of action and maintain over homeostasis of the body. There are various reports available showing the positive therapeutic effect of nutraceuticals in sport-related brain injury. Therefore, in the current article we have discussed the pathology, neurological consequence, sequelae, and perpetuation of sports-related brain injury. Further, we have discussed various nutraceutical supplements as well as available animal models to explore the neuroprotective effect/ upshots of these nutraceuticals in sports-related brain injury.

Serum antioxidant vitamin concentrations and oxidative stress markers associated with symptoms and severity of premenstrual syndrome: a prospective cohort study

Background

It has been suggested that premenstrual syndrome (PMS) may derive from either elevated oxidative stress or reduced antioxidant vitamin levels in the body; however, these relationships have been minimally studied in a large cohort of healthy women. Our objective was to estimate the association between serum concentrations of antioxidant vitamins (A, C, and E) and markers of oxidative stress (F2-isoprostane) with symptoms and severity of PMS.

Methods

The BioCycle study was a prospective cohort study following 259 healthy premenopausal women aged 18–44 years for up to 2 menstrual cycles. Frequency/severity of 20 PMS symptoms were assessed via questionnaires 4 times/cycle, and antioxidant vitamins and oxidative stress biomarkers were measured up to 8 times/cycle to correspond with specific cycle phases. Generalized linear models were used to estimate associations between mean antioxidant concentrations and oxidative stress biomarkers with PMS symptoms and severity; linear mixed models were used to evaluate associations with symptom severity scores within groups (e.g. depression, cravings, pain).

Results

Higher concentrations of serum antioxidant vitamins were largely not associated with prevalence or severity of PMS symptoms. Though a few associations were observed, only associations between mean γ-tocopherol and decreased odds of swelling of the hands/feet survived adjustment for multiple comparisons (OR 0.33, 95% CI 0.16, 0.65, per ug/dL). However, F2-isoprostanes were associated with prevalence and severity of several symptoms specifically related to depression and cravings (depression score β = 0.07, 95% CI 0.02, 0.12, per 10 ug/dL; cravings score β = 0.16, 95% CI 0.10, 0.22, per 10 ug/dL), as well as with classification of PMS severity (OR 1.07, 95% CI 1.01, 1.14, per 10 pg/dL), with these associations surviving adjustment for false discovery rate.

Conclusions

F2-isoprostanes, but not antioxidant vitamins, were associated with select PMS symptoms, as well as symptom and severity categories. Specific symptom relationships merit further research.

Preadministration of high-dose alpha-tocopherol improved memory impairment and mitochondrial dysfunction induced by proteasome inhibition in rat hippocampus

Objective: The ubiquitin-proteasome system plays a key role in memory consolidation. Proteasome inhibition and free radical-induced neural damage were implicated in neurodegenerative states. In this study, it was tested whether alpha-tocopherol (αT) in low and high doses could improve the long-term memory impairment induced by proteasome inhibition and protects against hippocampal oxidative stress. Methods: Alpha-tocopherol (αT) (60, 200 mg/kg, i.p. for 5 days) was administered to rats with memory deficit and hippocampal oxidative stress induced by bilateral intra-hippocampal injection of lactacystin (32 ng/μl) and mitochondrial evaluations were performed for improvement assessments. Results: The results showed that lactacystin significantly reduced the passive avoidance memory performance and increased the level of malondialdehyde (MDA), reactive oxygen species (ROS) and diminished the mitochondrial membrane potential (MMP) in the rat hippocampus. Furthermore, Intraperitoneal administration of αT significantly increased the passive avoidance memory, glutathione content and reduced ROS, MDA levels and impaired MMP. Conclusions: The results suggested that αT has neuroprotective effects against lactacystin-induced oxidative stress and memory impairment via the enhancement of hippocampal antioxidant capacity and concomitant mitochondrial sustainability. This finding shows a way to prevent and also to treat neurodegenerative diseases associated with mitochondrial impairment.

Pharmacology and Pharmacokinetics of Vitamin E: Nanoformulations to Enhance Bioavailability

Vitamin E belongs to the family of lipid-soluble vitamins and can be divided into two groups, tocopherols and tocotrienols, with four isomers (alpha, beta, gamma and delta). Although vitamin E is widely known as a potent antioxidant, studies have also revealed that vitamin E possesses anti-inflammatory properties. These crucial properties of vitamin E are beneficial in various aspects of health, especially in neuroprotection and cardiovascular, skin and bone health. However, the poor bioavailability of vitamin E, especially tocotrienols, remains a great limitation for clinical applications. Recently, nanoformulations that include nanovesicles, solid-lipid nanoparticles, nanostructured lipid carriers, nanoemulsions, and polymeric nanoparticles have shown promising outcomes in improving the efficacy and bioavailability of vitamin E. This review focuses on the pharmacological properties and pharmacokinetics of vitamin E and current advances in vitamin E nanoformulations for future clinical applications. The limitations and future recommendations are also discussed in this review.

Antioxidant Therapies in Traumatic Brain Injury

Due to a multiplicity of causes provoking traumatic brain injury (TBI), TBI is a highly heterogeneous pathology, characterized by high mortality and disability rates. TBI is an acute neurodegenerative event, potentially and unpredictably evolving into sub-chronic and chronic neurodegenerative events, with transient or permanent neurologic, cognitive, and motor deficits, for which no valid standardized therapies are available. A vast body of literature demonstrates that TBI-induced oxidative/nitrosative stress is involved in the development of both acute and chronic neurodegenerative disorders. Cellular defenses against this phenomenon are largely dependent on low molecular weight antioxidants, most of which are consumed with diet or as nutraceutical supplements. A large number of studies have evaluated the efficacy of antioxidant administration to decrease TBI-associated damage in various animal TBI models and in a limited number of clinical trials. Points of weakness of preclinical studies are represented by the large variability in the TBI model adopted, in the antioxidant tested, in the timing, dosages, and routes of administration used, and in the variety of molecular and/or neurocognitive parameters evaluated. The analysis of the very few clinical studies does not allow strong conclusions to be drawn on the real effectiveness of antioxidant administration to TBI patients. Standardizing TBI models and different experimental conditions, as well as testing the efficacy of administration of a cocktail of antioxidants rather than only one, should be mandatory. According to some promising clinical results, it appears that sports-related concussion is probably the best type of TBI to test the benefits of antioxidant administration.

High-Dose Intravenous Ascorbic Acid: Ready for Prime Time in Traumatic Brain Injury?

Traumatic brain injury (TBI) is one of the leading public health problems in the USA and worldwide. It is the number one cause of death and disability in children and adults between ages 1-44. Despite efforts to prevent TBIs, the incidence continues to rise. Secondary brain injury occurs in the first hours and days after the initial impact and is the most effective target for intervention. Inflammatory processes and oxidative stress play an important role in the pathomechanism of TBI and are exacerbated by impaired endogenous defense mechanisms, including depletion of antioxidants. As a reducing agent, free radical scavenger, and co-factor in numerous biosynthetic reactions, ascorbic acid (AA, vitamin C) is an essential nutrient that rapidly becomes depleted in states of critical illness. The administration of high-dose intravenous (IV) AA has demonstrated benefits in numerous preclinical models in the areas of trauma, critical care, wound healing, and hematology. A safe and inexpensive treatment, high-dose IV AA administration gained recent attention in studies demonstrating an associated mortality reduction in septic shock patients. High-quality data on the effects of high-dose IV AA on TBI are lacking. Historic data in a small number of patients demonstrate acute and profound AA deficiency in patients with central nervous system pathology, particularly TBI, and a strong correlation between low AA concentrations and poor outcomes. While replenishing deficient AA stores in TBI patients should improve the brain's ability to tolerate oxidative stress, high-dose IV AA may prove an effective strategy to prevent or mitigate secondary brain injury due to its ability to impede lipid peroxidation, scavenge reactive oxygen species, suppress inflammatory mediators, stabilize the endothelium, and reduce brain edema. The existing preclinical data and limited clinical data suggest that high-dose IV AA may be effective in lowering oxidative stress and decreasing cerebral edema. Whether this translates into improved clinical outcomes will depend on identifying the ideal target patient population and possible treatment combinations, factors that need to be evaluated in future clinical studies. With its excellent safety profile and low cost, high-dose IV AA is ready to be evaluated in the early treatment of TBI patients to mitigate secondary brain injury and improve outcomes.

Mesenchymal stromal cell secretome as a therapeutic strategy for traumatic brain injury

Traumatic brain injury (TBI) is a global health problem that is a common cause of disability and mortality. Despite the availability of many treatment options, none is capable of restoring functional and structural recovery of the damaged brain. Both the results of preclinical and clinical studies suggest the use of mesenchymal stromal cells (MSCs) as a therapeutic strategy for structural and functional recovery in TBI. However, recent evidence shows that the neuroprotective potential of MSCs is due to multiple secretions of bioactive molecules that modulate tissue microenvironment for tissue repair and regeneration. The results of preclinical studies indicate the therapeutic benefits of MSC secretome in TBI. Soluble bioactive molecules and extracellular vesicles are the various factors secreted by MSCs that can induce neurogenesis, angiogenesis, neovascularization, and anti-inflammatory activities. This review highlights the neuroprotective effect of MSC secretome for the treatment of TBI. In addition, the possible challenges of secretome as biotherapeutics are identified and how some of the issues raised could be overcome for effective clinical application are also discussed.

Nutritional interventions and cognitive-related outcomes in patients with late-life cognitive disorders: A systematic review

There have been a large number of observational studies on the impact of nutrition on neuroprotection, however, there was a lack of evidence from randomized clinical trials (RCTs). In the present systematic review, from the 32 included RCTs published in the last four years (2014-2017) in patients aged 60 years and older with different late-life cognitive disorders, nutritional intervention through medical food/nutraceutical supplementation and multidomain approach improved magnetic resonance imaging findings and other cognitive-related biomarkers, but without clear effect on cognition in mild Alzheimer's disease (AD) and mild cognitive impairment (MCI). Antioxidant-rich foods (nuts, grapes, cherries) and fatty acid supplementation, mainly n-3 polyunsaturated fatty acids (PUFA), improved specific cognitive domains and cognitive-related outcomes in MCI, mild-to-moderate dementia, and AD. Antioxidant vitamin and trace element supplementations improved only cognitive-related outcomes and biomarkers, high-dose B vitamin supplementation in AD and MCI patients improved cognitive outcomes in the subjects with a high baseline plasma n-3 PUFA, while folic acid supplementation had positive impact on specific cognitive domains in those with high homocysteine.

Antioxidants prevent inflammation and preserve the optic projection and visual function in experimental neurotrauma

We investigated the role of oxidative stress and the inflammasome in trauma-induced axon degeneration and vision loss using a mouse model. The left eyes of male mice were exposed to over-pressure air waves. Wild-type C57Bl/6 mice were fed normal, high-vitamin-E (VitE), ketogenic or ketogenic-control diets. Mice lacking the ability to produce vitamin C (VitC) were maintained on a low-VitC diet. Visual evoked potentials (VEPs) and retinal superoxide levels were measured in vivo. Tissue was collected for biochemical and histological analysis. Injury increased retinal superoxide, decreased SOD2, and increased cleaved caspase-1, IL-1α, IL-1β, and IL-18 levels. Low-VitC exacerbated the changes and the high-VitE diet mitigated them, suggesting that oxidative stress led to the increase in IL-1α and activation of the inflammasome. The injury caused loss of nearly 50% of optic nerve axons at 2 weeks and astrocyte hypertrophy in mice on normal diet, both of which were prevented by the high-VitE diet. The VEP amplitude was decreased after injury in both control-diet and low-VitC mice, but not in the high-VitE-diet mice. The ketogenic diet also prevented the increase in superoxide levels and IL-1α, but had no effect on IL-1β. Despite this, the ketogenic diet preserved optic nerve axons, prevented astrocyte hypertrophy, and preserved the VEP amplitude. These data suggest that oxidative stress induces priming and activation of the inflammasome pathway after neurotrauma of the visual system. Further, blocking the activation of the inflammasome pathway may be an effective post-injury intervention.

Peroxiredoxin-3 attenuates traumatic neuronal injury through preservation of mitochondrial function

Peroxiredoxins (PRDXs) are a highly conserved family of thiol peroxidases that scavenge peroxides in cells. PRDX3 is one member of PRDXs localized in the mitochondria, and has been shown to be involved in antioxidant defense and redox signaling. In this study, we investigated the role of PRDX3 in neuronal trauma using a traumatic neuronal injury (TNI) model in primary cultured cortical neurons. We found that TNI significantly decreased the expression of PRDX3 at both mRNA and protein levels. Overexpression of PRDX3 by lentivirus (LV-PRDX3) transfection attenuated lactate dehydrogenase (LDH) release and neuronal apoptosis after TNI. The results of immunostaining showed that LV-PRDX3 transfection markedly reduced TNI-induced intracellular ROS production, protein radical formation and lipid peroxidation. In addition, overexpression of PRDX3 preserved mitochondrial membrane potential (MMP) levels and ATP generation, and inhibited mitochondrial cytochrome c release in TNI-injured neurons. The results of polymerase chain reaction (PCR) showed that PRDX3 overexpression also increased mitochondrial DNA (mtDNA) content and upregulated the expression of mitochondrial biogenesis-related factors. Taken together, our data demonstrate that PRDX3 protects against TNI insult by preserving mitochondrial function and mitochondrial biogenesis, and may have potential therapeutic value for traumatic brain injury (TBI).

Antioxidant effects of Spirulina platensis (Arthrospira platensis) on cyclophosphamide-induced testicular injury in rats

Cyclophosphamide (CP) is known to reduce fertility. The protective effects of Spirulina plantesis (SP) against CP-induced testicular toxicity were investigated. Male Wistar rats were categorized into eight groups (n = 7). Four groups of rats were administered CP at a dose of 5 mg in 5 mL distilled water kg^-1 per day orally. Two of these groups were received SP (500 and 1000 mg kg^-1 per day) orally after CP administration. One of these groups was also received vitamin E (100 mg kg^-1 per day) intraperitoneally. A vehicle treated control group, two SP control groups (500 and 1000 mg kg^-1 per day) and a vitamin E control group were also included. Body and testes weights, sperm count, serum levels of glutathione peroxidase (GPx), malondialdehyde (MDA), histological and histomorphometric alternations in testes were investigated after four weeks. The CP-treated group exhibited significant decreases in the body and testes weights and spermatogenic activities. Several histological alterations were observed in this group. The CP treatment caused a significant reduction in sperm count, in serum level of GPx, as well increased serum concentration of MDA. The SP co-administration caused an increase in GPx serum level, a decrease in MDA serum level and improvements in histological and histomorphometric alternations. Vitamin E co-treatment showed partial recovery in above-mentioned parameters. These results suggest that SP due to a reduction in oxidative stress has more effective protection against CP-induced reproductive damages in rat than vitamin E.

Vitamin Supplementation as an Adjuvant Treatment for Alzheimer's Disease

Alzheimer's Disease (AD) is a slowly progressing neurodegenerative disorder representing a major health concern worldwide. This disorder is characterised by progressive dementia and cognitive decline. The pathological hallmarks of AD include the presence of Aβ plaques and tau neurofibrils. Research has shown that oxidative stress represents a major risk factor associated with AD pathology. Accumulation of Aβ plaques and relative lack of antioxidant defence mechanisms, including cellular antioxidant enzymes and dietary antioxidants like vitamins, assist in the exacerbation of oxidative stress. Reactive Oxygen Species (ROS) produced as the result of oxidative stress, that increase structural and functional abnormalities in brain neurons, which then manifests as dementia and decline in cognition. Data from numerous epidemiological studies suggests that nutrition is one of the most important yet modifiable risk factors for AD. Since oxidative stress contributes a great deal in the development and progression of AD, anything that could attenuate oxidative stress would help in decreasing the prevalence and incidence of AD. There is increasing evidence that supports the use of different antioxidant as an adjuvant treatment for AD. Vitamins are one such antioxidant that can be used as an adjuvant in AD treatment. This paper will focus on the evidence, based on current literature, linking the use of vitamin supplementations as an adjuvant treatment for AD.

Naringin improves zidovudine- and stavudine-induced skeletal muscle complications in rats

Chronic use of nucleoside reverse transcriptase inhibitors (NRTIs) in managing human immunodeficiency virus (HIV) infection has been associated with several complications. Available management options for these complications have yielded controversial results, thus the need to urgently find newer alternatives. Naringin, a plant-derived flavonoid, has been shown to possess antioxidant and antiapoptotic properties which can be exploited in managing NRTI-induced complications. This study therefore investigated the effects of naringin on some NRTI-induced complications. Forty-nine rats (200-250 g) were divided into seven groups and were orally treated with stavudine (d4T)-only, d4T + naringin, d4T + vitamin E, zidovudine (AZT)-only, AZT + naringin, AZT + vitamin E, and distilled water, respectively. Drugs were administered once daily for 56 days, and oral glucose tolerance tests conducted on day 54 of the experiments and rats were thereafter sacrificed on day 56 by halothane overdose. Plasma samples and the left gastrocnemius muscles were stored at -80°C for further analysis. There was significant glucose intolerance, insulin resistance, oxidative stress, and apoptosis in the skeletal muscles of AZT- or d4T-only-treated rats. Naringin, however, significantly reduced fasting blood glucose and fasting plasma insulin concentrations, mitigated glucose intolerance, and insulin resistance in addition to reducing malondialdehyde and carbonyl protein concentrations when coadministered with either NRTIs. Furthermore, naringin improved antioxidant enzyme activities, reduced skeletal muscle BCL-2-associated X protein expression, and improved B-cell lymphoma-2 protein expression compared to AZT- or d4T-only-treated rats. Naringin ameliorated AZT- and d4T-induced complications and therefore should be further investigated as a possible nutritional supplement in managing HIV infection.

Vitamins and nutrients as primary treatments in experimental brain injury: Clinical implications for nutraceutical therapies

With the numerous failures of pharmaceuticals to treat traumatic brain injury in humans, more researchers have become interested in combination therapies. This is largely due to the multimodal nature of damage from injury, which causes excitotoxicity, oxidative stress, edema, neuroinflammation and cell death. Polydrug treatments have the potential to target multiple aspects of the secondary injury cascade, while many previous therapies focused on one particular aspect. Of specific note are vitamins, minerals and nutrients that can be utilized to supplement other therapies. Many of these have low toxicity, are already FDA approved and have minimal interactions with other drugs, making them attractive targets for therapeutics. Over the past 20 years, interest in supplementation and supraphysiologic dosing of nutrients for brain injury has increased and indeed many vitamins and nutrients now have a considerable body of the literature backing their use. Here, we review several of the prominent therapies in the category of nutraceutical treatment for brain injury in experimental models, including vitamins (B2, B3, B6, B9, C, D, E), herbs and traditional medicines (ginseng, Gingko biloba), flavonoids, and other nutrients (magnesium, zinc, carnitine, omega-3 fatty acids). While there is still much work to be done, several of these have strong potential for clinical therapies, particularly with regard to polydrug regimens. This article is part of a Special Issue entitled SI:Brain injury and recovery.

Naringin Reverses Hepatocyte Apoptosis and Oxidative Stress Associated with HIV-1 Nucleotide Reverse Transcriptase Inhibitors-Induced Metabolic Complications

Nucleoside Reverse Transcriptase Inhibitors (NRTIs) have not only improved therapeutic outcomes in the treatment of HIV infection but have also led to an increase in associated metabolic complications of NRTIs. Naringin’s effects in mitigating NRTI-induced complications were investigated in this study. Wistar rats, randomly allotted into seven groups (n = 7) were orally treated daily for 56 days with 100 mg/kg zidovudine (AZT) (groups I, II III), 50 mg/kg stavudine (d4T) (groups IV, V, VI) and 3 mL/kg of distilled water (group VII). Additionally, rats in groups II and V were similarly treated with 50 mg/kg naringin, while groups III and VI were treated with 45 mg/kg vitamin E. AZT or d4T treatment significantly reduced body weight and plasma high density lipoprotein concentrations but increased liver weights, plasma triglycerides and total cholesterol compared to controls, respectively. Furthermore, AZT or d4T treatment significantly increased oxidative stress, adiposity index and expression of Bax protein, but reduced Bcl-2 protein expression compared to controls, respectively. However, either naringin or vitamin E significantly mitigated AZT- or d4T-induced weight loss, dyslipidemia, oxidative stress and hepatocyte apoptosis compared to AZT- or d4T-only treated rats. Our results suggest that naringin reverses metabolic complications associated with NRTIs by ameliorating oxidative stress and apoptosis. This implies that naringin supplements could mitigate lipodystrophy and dyslipidemia associated with NRTI therapy.

Melatonin reduces traumatic brain injury-induced oxidative stress in the cerebral cortex and blood of rats

Free radicals induced by traumatic brain injury have deleterious effects on the function and antioxidant vitamin levels of several organ systems including the brain. Melatonin possesses antioxidant effect on the brain by maintaining antioxidant enzyme and vitamin levels. We investigated the effects of melatonin on antioxidant ability in the cerebral cortex and blood of traumatic brain injury rats. Results showed that the cerebral cortex β-carotene, vitamin C, vitamin E, reduced glutathione, and erythrocyte reduced glutathione levels, and plasma vitamin C level were decreased by traumatic brain injury whereas they were increased following melatonin treatment. In conclusion, melatonin seems to have protective effects on traumatic brain injury-induced cerebral cortex and blood toxicity by inhibiting free radical formation and supporting antioxidant vitamin redox system.