α-Tocopherol Ameliorates Redox Equilibrium and Reduces Inflammatory Response Caused by Chronic Variable Stress

Vitamin E and conflicting understandings in noncommunicable diseases: Is it worth supplementing?

Vitamin E is a lipid-soluble nutrient found mainly in vegetable oils and oilseeds. It is divided into eight homologous compounds; however, only α-tocopherol exhibits vitamin activity. Many advantages are related to these compounds, including cellular protection through antioxidant and anti-inflammatory activity, and improving lipid metabolism. Physiopathology of many diseases incepts with reduced antioxidant defense, characterized by an increased reactive oxygen species production and activation of transcription factors involved in inflammation, such as nuclear factor-kappa B (NF-κB), that can be linked to oxidative stress. Moreover, disorders of lipid metabolism can increase the risk of cardiovascular diseases. In addition, intestinal dysbiosis plays a vital role in developing chronic non-communicable diseases. In this regard, vitamin E can be considered to mitigate those disorders, but data still needs to be more conclusive. This narrative review aims to elucidate the mechanisms of action of vitamin E and if supplementation can be beneficial in a disease scenario regarding non-communicable diseases.

Alteration in the Expression of Genes Involved in Cerebral Glucose Metabolism as a Process of Adaptation to Stressful Conditions

Exposure to chronic stress leads to disturbances in glucose metabolism in the brain, and changes in the functioning of neurons coexisting with the development of depression. The detailed molecular mechanism and cerebral gluconeogenesis during depression are not conclusively established. The aim of the research was to assess the expression of selected genes involved in cerebral glucose metabolism of mice in the validated animal paradigm of chronic stress. To confirm the induction of depression-like disorders, we performed three behavioral tests: sucrose preference test (SPT), forced swim test (FST), and tail suspension test (TST). In order to study the cerebral glucose metabolism of the brain, mRNA levels of the following genes were determined in the prefrontal cortex of mice: Slc2a3, Gapdh, Ldha, Ldhb, and Pkfb3. It has been shown that exogenous, chronic administration of corticosterone developed a model of depression in behavioral tests. There were statistically significant changes in the mRNA level of the Slc2a3, Ldha, Gapdh, and Ldhb genes. The obtained results suggest changes in cerebral glucose metabolism as a process of adaptation to stressful conditions, and may provide the basis for introducing new therapeutic strategies for chronic stress-related depression.

Effect of α-tocopherol in alleviating the lipopolysaccharide-induced acute lung injury via inhibiting nuclear factor kappa-B signaling pathways

Acute respiratory distress syndrome (ARDS) leads to the acute lung injury (ALI), a form of diffused alveolars injury, accompanied by severe inflammation and oxidative damage of alveolar epithelial cells. α-Tocopherol (α-TOH), one of the eight isoforms of vitamin E, is a natural antioxidant-free radical. We aimed to understand the effect of α-TOH and mechanism involved in inducing the ALI. Lipopolysaccharide (LPS) is injected into the trachea of mice to generate ALI mouse models. α-TOH was used to administrate the mice intragastrically to detect the expression of inflammatory factors and antioxidant molecules by enzyme linked immunosorbent assay, hematoxylin–eosin staining and immunohistochemical staining. Mouse alveolar epithelial cell line (MLE-12 cells) was used to determine the effect of α-TOH on alveolar epithelial cells. Inflammatory factors such as, interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α shows significant increase in the lung tissues of the mice induced by LPS and reduction in the expressions of superoxide dismutase (SOD)1/2 and glutathione peroxidase (GSH-Px). After treatment with α-TOH, the inflammation and oxidative stress levels shows substantial reduction in the lung tissues of the mice. Moreover, α-TOH also increases the proliferation ability of MLE-12 cells in vitro and reduces apoptosis level. In addition, α-TOH reduces p65 phosphorylation and nuclear translocation in alveolar epithelial cells in vivo and in vitro, thus, inhibiting the activity of the nuclear factor kappa-B (NF-κB) signaling pathway. α-TOH reduces the inflammation and oxidative stress of lung tissue by inhibiting the NF-κB signaling pathway, thereby alleviating the LPS-induced ALI.

Enjoy Carefully: The Multifaceted Role of Vitamin E in Neuro-Nutrition

Vitamin E is often associated with health benefits, such as antioxidant, anti-inflammatory and cholesterol-lowering effects. These properties make its supplementation a suitable therapeutic approach in neurodegenerative disorders, for example, Alzheimer’s or Parkinson’s disease. However, trials evaluating the effects of vitamin E supplementation are inconsistent. In randomized controlled trials, the observed associations often cannot be substantiated. This could be due to the wide variety of study designs regarding the dosage and duration of vitamin E supplementation. Furthermore, genetic variants can influence vitamin E uptake and/or metabolism, thereby distorting its overall effect. Recent studies also show adverse effects of vitamin E supplementation regarding Alzheimer’s disease due to the increased synthesis of amyloid β. These diverse effects may underline the inhomogeneous outcomes associated with its supplementation and argue for a more thoughtful usage of vitamin E. Specifically, the genetic and nutritional profile should be taken into consideration to identify suitable candidates who will benefit from supplementation. In this review, we will provide an overview of the current knowledge of vitamin E supplementation in neurodegenerative disease and give an outlook on individualized, sustainable neuro-nutrition, with a focus on vitamin E supplementation.

Chronic Stress and Oxidative Stress as Common Factors of the Pathogenesis of Depression and Alzheimer's Disease: The Role of Antioxidants in Prevention and Treatment

There is a growing body of scientific research showing the link between depression and dementia in Alzheimer’s disease (AD). The chronic stress contributes to the formation of oxidative stress in the parts of the brain involved in the development of depression and AD. The scientific literature reports the significant role of antioxidants, which are highly effective in treating these diseases. In this review, we have summarized the relationship between chronic stress, oxidative stress, and the changes in the brain they cause occurring in the brain. Among all the compounds showing antioxidant properties, the most promising results in AD treatment were observed for Vitamin E, coenzyme Q10 (CoQ10), melatonin, polyphenols, curcumin, and selenium. In case of depression treatment, the greatest potential was observed in curcumin, zinc, selenium, vitamin E, and saffron.

White rice ethanol extract is qualitatively, but not quantitatively, equivalent to that of brown rice as an antioxidant source

The purpose of this study is to compare the potentials to exhibit biologically active antioxidant actions between white rice (WR) and brown rice (BR) in in vitro assays and a cellular model. The Trolox equivalent (TE) per 1 mg ethanol extract of WR for the 1,1-diphenyl-2-picrylhydrazyl assay was slightly higher than that of BR, whereas the TE per 1 g whole WR was much lower than that for BR. This tendency was very comparable to those for the oxygen radical absorbance capacity and total polyphenol content. Both of the ethanol extracts also similarly suppressed the hydrogen peroxide-induced cytotoxicity and enhanced the gene expression of drug-metabolizing enzymes. Based on the α-tocopherol quantity, its contribution to the cytoprotective effect of the rice extracts is very limited. Taken together, the ethanol extract of WR might be a qualitatively, but not quantitatively, equivalent source of antioxidative phytochemicals to that of BR.

Role of the Intestinal Microbiome, Intestinal Barrier and Psychobiotics in Depression

The intestinal microbiota plays an important role in the pathophysiology of depression. As determined, the microbiota influences the shaping and modulation of the functioning of the gut-brain axis. The intestinal microbiota has a significant impact on processes related to neurotransmitter synthesis, the myelination of neurons in the prefrontal cortex, and is also involved in the development of the amygdala and hippocampus. Intestinal bacteria are also a source of vitamins, the deficiency of which is believed to be related to the response to antidepressant therapy and may lead to exacerbation of depressive symptoms. Additionally, it is known that, in periods of excessive activation of stress reactions, the immune system also plays an important role, negatively affecting the tightness of the intestinal barrier and intestinal microflora. In this review, we have summarized the role of the gut microbiota, its metabolites, and diet in susceptibility to depression. We also describe abnormalities in the functioning of the intestinal barrier caused by increased activity of the immune system in response to stressors. Moreover, the presented study discusses the role of psychobiotics in the prevention and treatment of depression through their influence on the intestinal barrier, immune processes, and functioning of the nervous system.

Vitamin E for the management of major depressive disorder: possible role of the anti-inflammatory and antioxidant systems

OBJECTIVES

Vitamin E has various functions in humans, including antioxidant, anti-inflammatory, anti-cancer, and anti-atherogenic actions, as well as direct effects on enzymatic activities and modulation of gene transcription. In addition to these functions, vitamin E is also important for the central nervous system, and its role in the prevention and/or treatment of some neurological diseases has been suggested. In particular, the role of vitamin E in the modulation of major depressive disorder (MDD) is an issue that has emerged in recent studies. Many factors have been implicated in the pathophysiology of this disorder, including inflammation, oxidative, and nitrosative stress.

METHODS

This narrative review discusses the involvement of inflammation, oxidative, and nitrosative stress in the pathophysiology of MDD and presents clinical and preclinical studies that correlate vitamin E with this psychiatric disorder.

RESULTS

We gathered evidence from clinical studies that demonstrated the relationship between low vitamin E status and MDD symptoms. Vitamin E has been reported to exert a beneficial influence on the oxidative and inflammatory status of individuals, factors that may account for the attenuation of depressive symptoms. Preclinical studies have reinforced the antidepressant-like response of vitamin E, and the mechanisms underlying its effect seem to be related to the modulation of oxidative stress and neuroinflammation.

CONCLUSION

We suggest that vitamin E has potential to be used as an adjuvant for the management of MDD, but more studies are clearly needed to ascertain the efficacy of vitamin E for alleviating depressive symptoms.

Oxidative Stress at the Crossroads of Aging, Stroke and Depression

Epidemiologic studies have shown that in the aging society, a person dies from stroke every 3 minutes and 42 seconds, and vast numbers of people experience depression around the globe. The high prevalence and disability rates of stroke and depression introduce enormous challenges to public health. Accumulating evidence reveals that stroke is tightly associated with depression, and both diseases are linked to oxidative stress (OS). This review summarizes the mechanisms of OS and OS-mediated pathological processes, such as inflammation, apoptosis, and the microbial-gut-brain axis in stroke and depression. Pathological changes can lead to neuronal cell death, neurological deficits, and brain injury through DNA damage and the oxidation of lipids and proteins, which exacerbate the development of these two disorders. Additionally, aging accelerates the progression of stroke and depression by overactive OS and reduced antioxidant defenses. This review also discusses the efficacy and safety of several antioxidants and antidepressants in stroke and depression. Herein, we propose a crosstalk between OS, aging, stroke, and depression, and provide potential therapeutic strategies for the treatment of stroke and depression.

Cardioprotective potential of polyphenols rich Thraatchathi Chooranam against isoproterenol induced myocardial necrosis in experimental rats

BACKGROUND

The present study establishes the cardioprotective role of Thraatchathi Chooranam (TC), a polyherbal traditional Siddha medicine, in terms of membrane stabilizing and antioxidant properties in isoproterenol (ISO) induced myocardial necrosis model in rats.

METHODS

Animals were divided into six groups (n = 6), normal (received vehicle 0.5% CMC, p.o.), ISO control (received 0.5% CMC + ISO 120 mg/kg, b.w. s.c. twice at an interval of 48 h), standard control (received Vit-E 100 mg/kg, p.o.) + ISO, TC low and high dose (50 and 100 mg/kg p.o., respectively) + ISO, and drug control (received TC at 100 mg/kg, p.o.). At the end of experimental period, blood samples collected and plasma cardiac troponin-I (CTn-I) was measured by ELISA. Cardiac tissues were isolated, levels of membrane stabilizing enzymes, antioxidants and inflammatory markers were estimated. Gene expression of Bax, Bcl2, Caspase 3, HIF-α, TNF-α, iNOS, TRX1 and TrxR were performed by RT-PCR. Histopathological studies on cardiac tissues were conducted using hematoxylin and eosin (H&E) stain. Statistical analyses were performed by one-way ANOVA followed by Tukey's multiple comparison as post-hoc test.

RESULTS

Administration of ISO resulted in a significant increase in plasma CTn-I, decrease in superoxide dismutase, glutathione and glutathione peroxidase; it also significantly altered membrane stabilizing enzymes like Na⁺/K⁺-ATPase, Mg²⁺-ATPase Ca²⁺-ATPase and Cathepsin D. Pretreatment with TC (50 mg/kg and 100 mg/kg) decreased CTn-I, and improved membrane stabilizing and endogenous antioxidant enzymes and decreased cathespin D level in a dose dependent manner. Histopathological examination revealed that TC improves cellular membrane integrity and decreases inflammatory cell infiltration and necrotic death.

CONCLUSION

The present study provided a strong evidence on the protective effects of TC against ISO-induced myocardial necrosis in rats.

Morin hydrate attenuates chronic stress-induced memory impairment and degeneration of hippocampal subfields in mice: The role of oxidative, nitrergic and neuroinflammatory pathways

Morin hydrate (MH) is the major flavonoid constituent of Morus alba acclaimed to have antioxidant, anti-inflammatory, anti-stress and neuroprotective properties. However, report on the effect of MH on memory performance and the underlying mechanism following chronic stress exposure is lacking. The current study aimed at investigating the neuroprotective effect of MH on chronic unpredictable stress (CUS)-induced memory impairment in mice using the Y maze test. Mice were subjected to unpredicted stress for 14 days, during which MH (5, 10 and 20 mg/kg i.p) or 25 mg/kg Ginseng was administered to them. On the 14th day, 1 h after treatment, learning and memory deficit was evaluated using the Y maze test and thereafter brains were harvested for the estimation of glutathione (GSH), lipid peroxidation product; malondialdehyde (MDA) and nitrite. Levels of inflammatory mediators tumor necrosis factor-alpha (TNF-α) and interleukin1-beta (IL-1β), inducible nitric oxide synthase (iNOS) and nuclear factor-kappa B (NF-кB) expressions were also determined. The hippocampus was stained with hematoxylin-eosin (H&E) to examine any morphological changes in the neurons. Mice exposed to CUS showed evidence of impaired memory and increase levels of MDA, nitrite, TNF-α and IL-1β. Furthermore, CUS reduced GSH level, increased the expressions of iNOS and NFкB immune-positive cells and produced loss of neuronal cells in the hippocampus. The MH treatment however improved memory, reduced MDA and nitrite levels, and enhanced brain GSH levels in CUS-mice. Besides, MH reduced brain levels of TNF-α and IL-1β levels, down regulated the expressions of iNOS and NF-кB and rescue neurons in the hippocampal CA3 region of mice exposed to CUS. The results of the study indicate that MH improved CUS-induced memory impairment, which may be related to its ability to boost antioxidant defense system and suppress neuroinflammatory pathways.

Adjuvant Therapies in Diabetic Retinopathy as an Early Approach to Delay Its Progression: The Importance of Oxidative Stress and Inflammation

Diabetes mellitus (DM) is a progressive disease induced by a sustained state of chronic hyperglycemia that can lead to several complications targeting highly metabolic cells. Diabetic retinopathy (DR) is a multifactorial microvascular complication of DM, with high prevalence, which can ultimately lead to visual impairment. The genesis of DR involves a complex variety of pathways such as oxidative stress, inflammation, apoptosis, neurodegeneration, angiogenesis, lipid peroxidation, and endoplasmic reticulum (ER) stress, each possessing potential therapeutic biomarkers. A specific treatment has yet to be developed for early stages of DR since no management is given other than glycemic control until the proliferative stage develops, offering a poor visual prognosis to the patient. In this narrative review article, we evaluate different dietary regimens, such as the Mediterranean diet, Dietary Pattern to Stop Hypertension (DASH) and their functional foods, and low-calorie diets (LCDs). Nutraceuticals have also been assessed in DR on account of their antioxidant, anti-inflammatory, and antiangiogenic properties, which may have an important impact on the physiopathology of DR. These nutraceuticals have shown to lower reactive oxygen species (ROS), important inflammatory factors, cytokines, and endothelial damage biomarkers either as monotherapies or combined therapies or concomitantly with established diabetes management or nonconventional adjuvant drugs like topical nonsteroidal anti-inflammatory drugs (NSAIDs).