Supplementation with γ-tocopherol attenuates endotoxin-induced airway neutrophil and mucous cell responses in rats

Association between DASH diet and asthma symptoms among a large sample of adolescents: a cross-sectional study

BACKGROUND

The Dietary Approaches to Stop Hypertension (DASH) diet, which has a lot of emphasis on the consumption of fruits, vegetables, and whole grains, and on the other hand, the consumption of red meat and sodium is limited, due to its anti-inflammatory properties, which can be related to reducing the risk of asthma.

OBJECTIVES

The aim of this study was to determine the relationship between the DASH diet and asthma symptoms among children and adolescents.

METHODS

This cross-sectional study was conducted among7667 children (3414 boys and 4253 girls) aged 6-7 and 13-14 years living in central Iran. Dietary food consumption was assessed using a multiple-choice questionnaire. Logistic regression was used to obtain odds ratios for the association between the DASH-like diet with current asthma and asthma symptoms.

RESULTS

Our findings revealed that higher adherence to a DASH-like diet resulted in lower odds of asthma confirmed by a doctor among the whole population (OR = 0.53; 95%CI: 0.36-0.76) and also in females (OR = 0.47; 95%CI: 0.29-0.78). Moreover, the higher adherence to the DASH-like diet was inversely associated with the chance of wheezing in the past 12 months in all subjects (OR = 0.67; 95%CI: 0.51-0.86) and in boys (OR = 0.57; 95%CI: 0.38-0.85).

CONCLUSION

The findings of the present study showed that following the DASH diet can be associated with the improvement of asthma symptoms in children and adolescents. However, more research is needed to improve dietary recommendations for asthma prevention.

Reactive Oxygen Species and Strategies for Antioxidant Intervention in Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is a life-threatening pulmonary condition characterized by the sudden onset of respiratory failure, pulmonary edema, dysfunction of endothelial and epithelial barriers, and the activation of inflammatory cascades. Despite the increasing number of deaths attributed to ARDS, a comprehensive therapeutic approach for managing patients with ARDS remains elusive. To elucidate the pathological mechanisms underlying ARDS, numerous studies have employed various preclinical models, often utilizing lipopolysaccharide as the ARDS inducer. Accumulating evidence emphasizes the pivotal role of reactive oxygen species (ROS) in the pathophysiology of ARDS. Both preclinical and clinical investigations have asserted the potential of antioxidants in ameliorating ARDS. This review focuses on various sources of ROS, including NADPH oxidase, uncoupled endothelial nitric oxide synthase, cytochrome P450, and xanthine oxidase, and provides a comprehensive overview of their roles in ARDS. Additionally, we discuss the potential of using antioxidants as a strategy for treating ARDS.

Gamma-tocopherol, a major form of vitamin E in diets: Insights into antioxidant and anti-inflammatory effects, mechanisms, and roles in disease management

γ-Tocopherol (γT) is a major form of vitamin E in the US diet and the second most abundant vitamin E in the blood and tissues, while α-tocopherol (αT) is the predominant vitamin E in tissues. During the last >25 years, research has revealed that γT has unique antioxidant and anti-inflammatory activities relevant to disease prevention compared to αT. While both compounds are potent lipophilic antioxidants, γT but not αT can trap reactive nitrogen species by forming 5-nitro-γT, and appears to show superior protection of mitochondrial function. γT inhibits ionophore-stimulated leukotrienes by blocking 5-lipoxygenase (5-LOX) translocation in leukocytes, decreases cyclooxygenase-2 (COX-2)-catalyzed prostaglandins in macrophages and blocks the growth of cancer cells but not healthy cells. For these activities, γT is stronger than αT. Moreover, γT is more extensively metabolized than αT via cytochrome P-450 (CYP4F2)-initiated side-chain oxidation, which leads to formation of metabolites including 13'-carboxychromanol (13'-COOH) and carboxyethyl-hydroxychroman (γ-CEHC). 13'-COOH and γ-CEHC are shown to be the predominant metabolites found in feces and urine, respectively. Interestingly, γ-CEHC has natriuretic activity and 13'-COOH inhibits both COX-1/-2 and 5-LOX activity. Consistent with these mechanistic findings of γT and metabolites, studies show that supplementation of γT mitigates inflammation and disease symptoms in animal models with induced inflammation, asthma and cancer. In addition, supplementation of γT decreased inflammation markers in patients with kidney diseases and mild asthma. These observations support that γT may be useful against inflammation-associated diseases.

Vitamin E beyond Its Antioxidant Label

Vitamin E, comprising tocopherols and tocotrienols, is mainly known as an antioxidant. The aim of this review is to summarize the molecular mechanisms and signaling pathways linked to inflammation and malignancy modulated by its vitamers. Preclinical reports highlighted a myriad of cellular effects like modulating the synthesis of pro-inflammatory molecules and oxidative stress response, inhibiting the NF-κB pathway, regulating cell cycle, and apoptosis. Furthermore, animal-based models have shown that these molecules affect the activity of various enzymes and signaling pathways, such as MAPK, PI3K/Akt/mTOR, JAK/STAT, and NF-κB, acting as the underlying mechanisms of their reported anti-inflammatory, neuroprotective, and anti-cancer effects. In clinical settings, not all of these were proven, with reports varying considerably. Nonetheless, vitamin E was shown to improve redox and inflammatory status in healthy, diabetic, and metabolic syndrome subjects. The anti-cancer effects were inconsistent, with both pro- and anti-malignant being reported. Regarding its neuroprotective properties, several studies have shown protective effects suggesting vitamin E as a potential prevention and therapeutic (as adjuvant) tool. However, source and dosage greatly influence the observed effects, with bioavailability seemingly a key factor in obtaining the preferred outcome. We conclude that this group of molecules presents exciting potential for the prevention and treatment of diseases with an inflammatory, redox, or malignant component.

Dynamic Characteristics of Sequential Acute Exacerbations and Risk Windows in AECOPD Rats Induced by Cigarette-Smoke and Exposure to Klebsiella pneumoniae

The risk-window (RW) of chronic obstructive pulmonary disease (COPD) is a period after an acute exacerbation (AE) but before the following stable phase, in which exacerbations are easy to relapse. We established a sequential COPD-AE-RW rat model by cigarette-smoke and bacterial exposures in the first 8 weeks, and was challenged with Klebsiella pneumonia to mimic an AE on Day 1 of week 9, and found that body temperature, white blood cell, neutrophils, serum amyloid A (SAA) and C-reactive protein (CRP) increased in AECOPD rats 24 h after challenge, and declined in 3-6 d, while lung function declined in 48 h, and recovered in 7-16 d. When sacrificed, pulmonary forced expiratory volume (FEV)100 and FEV300 decreased, while elevated bronchoalveolar lavage fluid (BALF) neutrophils and marked airway inflammation, remodeling and emphysema were observed. Sequential COPD-AE-RW rat model was established successfully and AE phase lasts for approximately 5-7 d, followed by a 10-d around risk-window.

Study of supercritical CO2 extraction of tamarillo (Cyphomandra Betacea) seed oil containing high added value compounds

In the present investigation, the extraction of tamarillo seed oil was conducted using supercritical carbon dioxide (SC-CO2), under different conditions of pressure (20-38.1 MPa) and temperature (40-64°C). In order to determine the effect that these extraction parameters have over the yield and composition of the oil, a central composite design was used. The optimum yield was 21.07% obtained at 38.1 MPa and 64°C. The fatty acids of the tamarillo seed oil obtained with SC-CO2 were identified: linoleic (70.12%), oleic (16.18%), palmitic (9.68%), stearic (2.12%), linolenic (1.70%), and palmitoleic (0.23%). Other components, such as squalene (2.96-19.75 mg/mL), β-sitosterol (2.05-3.68 mg/mL), cycloartenol (1,23-2.81 mg/mL) dihydrolanosterol (0.28-0.70 mg/mL) sterols and γ-tocopherol (0.89-2.10 mg/mL) were also noted. The extraction kinetic was studied at 27.5 MPa -50°C and 38.1 MPa -64°C. The semi-empirical model of Sovová et al. [24] described 99.21% of the experimental behavior of extraction kinetics. High yields of tamarillo seed oil, as well as its unique composition of unsaturated fatty acids and minor components, show the potential for its application in the food, cosmetic, and pharmaceutical industries.

ROS Signaling in the Pathogenesis of Acute Lung Injury (ALI) and Acute Respiratory Distress Syndrome (ARDS)

The generation of reactive oxygen species (ROS) plays an important role for the maintenance of cellular processes and functions in the body. However, the excessive generation of oxygen radicals under pathological conditions such as acute lung injury (ALI) and its most severe form acute respiratory distress syndrome (ARDS) leads to increased endothelial permeability. Within this hallmark of ALI and ARDS, vascular microvessels lose their junctional integrity and show increased myosin contractions that promote the migration of polymorphonuclear leukocytes (PMNs) and the transition of solutes and fluids in the alveolar lumen. These processes all have a redox component, and this chapter focuses on the role played by ROS during the development of ALI/ARDS. We discuss the origins of ROS within the cell, cellular defense mechanisms against oxidative damage, the role of ROS in the development of endothelial permeability, and potential therapies targeted at oxidative stress.

Gamma tocopherol-enriched supplement reduces sputum eosinophilia and endotoxin-induced sputum neutrophilia in volunteers with asthma

BACKGROUND

We and others have shown that the gamma tocopherol (γT) isoform of vitamin E has multiple anti-inflammatory and antioxidant actions and that γT supplementation reduces eosinophilic and endotoxin (LPS)-induced neutrophilic airway inflammation in animal models and healthy human volunteers.

OBJECTIVE

We sought to determine whether γT supplementation reduces eosinophilic airway inflammation and acute neutrophilic response to inhaled LPS challenge in volunteers with asthma.

METHODS

Participants with mild asthma were enrolled in a double-blinded, placebo-controlled crossover study to assess the effect of 1200 mg of γT daily for 14 days on sputum eosinophils, mucins, and cytokines. We also assessed the effect on acute inflammatory response to inhaled LPS challenge following γT treatment, focusing on changes in sputum neutrophilia, mucins, and cytokines. Mucociliary clearance was measured using gamma scintigraphy.

RESULTS

Fifteen subjects with mild asthma completed both arms of the study. Compared with placebo, γT notably reduced pre-LPS challenge sputum eosinophils and mucins, including mucin 5AC and reduced LPS-induced airway neutrophil recruitment 6 and 24 hours after challenge. Mucociliary clearance was slowed 4 hours postchallenge in the placebo group but not in the γT treatment group. Total sputum mucins (but not mucin 5AC) were reduced at 24 hours postchallenge during γT treatment compared with placebo.

CONCLUSIONS

When compared with placebo, γT supplementation for 14 days reduced inflammatory features of asthma, including sputum eosinophils and mucins, as well as acute airway response to inhaled LPS challenge. Larger scale clinical trials are needed to assess the efficacy of γT supplements as a complementary or steroid-sparing treatment for asthma.

Many tocopherols, one vitamin E

Four tocopherols are available in nature and are absorbed with the diet, but only one RRR-α-tocopherol satisfies the criteria of being a vitamin. The biological activity of the different tocopherols studied in the rat by the resorption-gestation test has been inconsistently extrapolated to human beings where the tocopherols have no influence on a successful pregnancy. Diminution of RRR-α-tocopherol intake results in diseases characterized by ataxia, whose pathogenetic mechanism, despite vigorous claims, has not been clarified. The calculation of the Daily Reference Intake (DRI), necessary to prevent disease, is based on an obsolete test, the peroxide-induced erythrocyte hemolysis, called the gold standard, but of highly questioned validity. If many epidemiological studies have given positive results, showing prevention by high vitamin E containing diets of cardiovascular events, neurodegenerative disease, macular degeneration and cancer, the clinical confirmatory intervention studies were mostly negative. On the positive side, besides preventing vitamin E deficiency diseases, vitamin E has shown efficacy as anti-inflammatory and immune boosting compound. It has also shown some efficacy in protecting against nonalcoholic hepato-steatosis. At a molecular level, vitamin E and some of its metabolites have shown capacity of regulating cell signaling and modulating gene transcription.

Chronic intermittent hypoxia decreases pulmonary clearance of 99mTc-labelled particulate matter in mice

BACKGROUND

Obstructive sleep apnea-hypopnea syndrome (OSAHS) could cause systematic inflammation including pulmonary inflammatory response, whereas the influence of OSAHS in pulmonary clearance ability remains unknown. The main pathophysiological feature of OSAHS is chronic intermittent hypoxia (CIH). The goal of this study is to clarify the airway clearance of particulate matter (PM) in CIH mice, and to explore the potential mechanism.

METHODS

Balb/c mice were divided into a CIH group and a control group, exposed to intermittent hypoxia and air chamber, respectively. A radioactive probe, ^99mTc labeled PM, was endotracheally inserted into the mice at 10 mg/kg, with a starting dose of 800 μCi. The change of radioactive dose reserved in the lung was observed using single-photon emission computed tomography/computed tomography (SPECT/CT) and reconstructed data were analyzed. Special airway resistance (sRaw) of mice was measured by non-invasive airway mechanics sites. Lung resistive load (R_L), elastic resistance, and compliance were measured by a multichannel physiological signal system. Lung injury was judged by hematoxylin-eosin staining and histologic score. Change in mucus secretion was determined using periodic acid-Schiff staining and enzyme-linked immunosorbent assay. Fresh lung tissue was used for real-time polymerase chain reaction and western blot analysis to explore related change of inflammation and signaling molecules and potential mechanical pathway.

RESULTS

Mice in the CIH group had higher PM radioactive deposit than the control group (93.37±3.44 μCi vs. 65.98±2.61 μCi). The average radiation dose in the lung was elevated (0.0005 μCi/mm³ vs. 0.0001383 μCi/mm³). Mice in the CIH group have higher value of sRaw, R_L, and elastic resistance, whereas pulmonary compliance decreased compared to the control group (2.13±0.29 mL/cmH₂O vs. 5.37±1.02 mL/cmH₂O). The CIH group showed a higher histopathological score. Several genes associated with mucin secretion such as chemokine (C-X-C motif) ligand 1 (CXCL1), Clara Cell Secretory Protein 16 (CC16), macrophage inflammatory protein 2 (MIP-2), chloride channel regulator 1 (Gob5), and mucin 5AC (MUC5AC) showed elevated expression. Phosphatidylinostol-3-kinase/serine/threonine-specific protein kinase (PI3K/AKT) pathway was activated in the CIH group.

CONCLUSIONS

CIH decreased pulmonary clearance of PM and increased lung airway resistance, which may be related to inflammatory response and mucus hypersecretion in the lung.

α-Tocopherol transfer protein mediates protective hypercapnia in murine ventilator-induced lung injury

RATIONALE

Hypercapnia is common in mechanically ventilated patients. Experimentally, 'therapeutic hypercapnia' can protect, but it can also cause harm, depending on the mechanism of injury. Hypercapnia suppresses multiple signalling pathways. Previous investigations have examined mechanisms that were known a priori, but only a limited number of pathways, each suppressed by CO₂, have been reported.

OBJECTIVE

Because of the complexity and interdependence of processes in acute lung injury, this study sought to fill in knowledge gaps using an unbiased screen, aiming to identify a specifically upregulated pathway.

METHODS AND RESULTS

Using genome-wide gene expression analysis in a mouse model of ventilator-induced lung injury, we discovered a previously unsuspected mechanism by which CO₂ can protect against injury: induction of the transporter protein for α-tocopherol, α-tocopherol transfer protein (αTTP). Pulmonary αTTP was induced by inspired CO₂ in two in vivo murine models of ventilator-induced lung injury; the level of αTTP expression correlated with degree of lung protection; and, absence of the αTTP gene significantly reduced the protective effects of CO₂. α-Tocopherol is a potent antioxidant and hypercapnia increased lung α-tocopherol in wild-type mice, but this did not alter superoxide generation or expression of NRF2-dependent antioxidant response genes in wild-type or in αTTP^-/- mice. In concordance with a regulatory role for α-tocopherol in lipid mediator synthesis, hypercapnia attenuated 5-lipoxygenase activity and this was dependent on the presence of αTTP.

CONCLUSIONS

Inspired CO₂ upregulates αTTP which increases lung α-tocopherol levels and inhibits synthesis of a pathogenic chemoattractant.

Vitamin E and the risk of childhood asthma

INTRODUCTION

Asthma, a heterogeneous disease with multiple phenotypes, remains a significant health problem. Present treatments are not curative and prevention should be our ultimate goal. Vitamin E supplementation presents a potential easy and cheap preventive therapy but the results of studies are confusing and sometimes contradictory. Clarification is needed.

AREAS COVERED

Animal studies and research in pregnant women suggest enhanced lifetime resistance to asthma with appropriate fetal exposure to vitamin E. Vitamin E's preventive role is complex and includes functional variations of the different isoforms. Expert commentary: We review the most recent literature on the role of vitamin E isoforms on: lung inflammation, immune development, animal and clinical studies during pregnancy, and the potential influence of vitamin E isoforms on asthma development in offspring. We point out where data are seemingly contradictory, explain why this is so, and comment on where further clarifying research is needed and its future direction.

Interactions between Autophagy and Bacterial Toxins: Targets for Therapy?

Autophagy is a physiological process involved in defense mechanisms for clearing intracellular bacteria. The autophagic pathway is finely regulated and bacterial toxins interact with this process in a complex manner. Bacterial toxins also interact significantly with many biochemical processes. Evaluations of the effects of bacterial toxins, such as endotoxins, pore-forming toxins and adenylate cyclases, on autophagy could support the development of new strategies for counteracting bacterial pathogenicity. Treatment strategies could focus on drugs that enhance autophagic processes to improve the clearance of intracellular bacteria. However, further in vivo studies are required to decipher the upregulation of autophagy and potential side effects limiting such approaches. The capacity of autophagy activation strategies to improve the outcome of antibiotic treatment should be investigated in the future.

Diet and asthma: an update

PURPOSE OF REVIEW

Our objective was to provide an overview and discussion of recent experimental studies, epidemiologic studies, and clinical trials of diet and asthma. We focus on dietary sources and vitamins with antioxidant properties [vitamins (A, C, and E), folate, and omega-3 and omega-6 polyunsaturated fatty acids (n-3 and n-6 PUFAs)].

RECENT FINDINGS

Current evidence does not support the use of vitamin A, vitamin C, vitamin E, or PUFAs for the prevention or treatment of asthma or allergies. Current guidelines for prenatal use of folate to prevent neural tube defects should be followed, as there is no evidence of major effects of this practice on asthma or allergies. Consumption of a balanced diet that is rich in sources of antioxidants (e.g. fruits and vegetables) may be beneficial in the primary prevention of asthma.

SUMMARY

None of the vitamins or nutrients examined is consistently associated with asthma or allergies. In some cases, further studies of the effects of a vitamin or nutrient on specific asthma phenotypes (e.g. vitamin C to prevent viral-induced exacerbations) are warranted. Clinical trials of 'whole diet' interventions to prevent asthma are advisable on the basis of existing evidence.

Serum cytokines and muscle strength after anterior cruciate ligament surgery are not modulated by high-doses of vitamins E (α- and γ-tocopherol's) and C

The purpose of this investigation was to identify if supplemental vitamin E (consisting of α- and γ-tocopherol's) and C modulate serum cytokine and muscle strength following an ACL injury and surgery. Subjects were randomly assigned to one of two groups: (1) placebo (n=14) or (2) vitamins E (α-[600m g RRR-α-tocopherol, αT] and γ-[600 mg of RRR-γT]) and C (1000 mg ascorbic acid, AA) (EC; n=15). Supplements were taken daily starting ∼2-wk prior to and concluding 16-wk after surgery. Fasting blood samples were obtained and single-leg peak isometric force measurements were performed at baseline (prior to supplementation), before surgery (∼120-min - blood draw only), and 8-wk, 12-wk, and 16-wk after surgery. αT, γT, AA, and cytokines were measured in each blood sample, and peak isometric force was measured on the injured and non-injured legs separately at each testing session. An exercise protocol consisting of repetitive knee and hip extension and flexion contractions to exhaustion was performed on the injured limb at 16-wk. Vitamin E and C supplementation significantly (all p<0.05) increased plasma αT (∼40%), γT (∼160%), and AA (∼50%) concentrations. Serum cytokine concentrations, peak isometric force, and time to exhaustion during the exercise protocol were not significantly different between groups. Based on these findings, we conclude that vitamin E and C supplementation increases their endogenous levels without minimizing muscular weakness or modulating serum cytokine concentrations after ACL surgery.

Serum tocopherol levels and vitamin E intake are associated with lung function in the normative aging study

BACKGROUND & AIMS

The results of studies assessing relationships between vitamin E intake and status and lung function are conflicting. This study aimed to evaluate the effect of vitamin E intake and serum levels of tocopherol isoforms on lung function in a cross-sectional sample of 580 men from the Normative Aging Study, a longitudinal aging study.

METHODS

Regression models were used to look at associations of serum tocopherol isoform levels and vitamin E intake with lung function parameters after adjustment for confounders. Vitamin E intake was measured using a food frequency questionnaire and serum levels of γ, α, and δ-tocopherol levels were measured using high-performance liquid chromatography.

RESULTS

After adjustment for potential confounders, serum γ-tocopherol had a significant inverse association with forced vital capacity (β = -0.10, p = 0.05). Alpha and δ-tocopherol were not associated with any lung function parameter. After classifying COPD status according to Global Initiative for Obstructive Lung Disease (GOLD) stage criteria, serum levels of δ-tocopherol were lower in participants with more severe COPD (p = 0.01). Serum levels of δ-tocopherol were also lower in participants with greater levels of smoking (p = 0.02). Both vitamin E intake (β = 0.03, p = 0.02; β = 0.03, p = 0.01) and use of vitamin E supplements (β = 0.05, p = 0.03; β = 0.06. p = 0.02) were positively associated with FEV1 and FVC, after adjusting for confounders. Subjects who took vitamin E supplements had significantly higher α-tocopherol levels (p < 0.0001) and lower γ-tocopherol levels (p < 0.0001) than non-users.

CONCLUSION

In this study, there is a positive association between dietary vitamin E intake and lung function, and evidence of an inverse relationship between serum levels of γ-tocopherol and lung function.

Betulinic acid attenuates lung injury by modulation of inflammatory cytokine response in experimentally-induced polymicrobial sepsis in mice

Sepsis commonly progresses to acute lung injury (ALI), an inflammatory lung disease with high morbidity and mortality. Septic ALI is characterized by excessive production of proinflammatory mediators. It remained refractory to present therapies and new therapies need to be developed to improve further clinical outcomes. Betulinic acid (BA), a pentacyclic lupane group triterpenoid has been shown to have anti-inflammatory activities in many studies. However, its therapeutic efficacy in polymicrobial septic ALI is yet unknown. Therefore, we investigated the effects of BA on septic ALI using cecal ligation and puncture (CLP) model in mice. Vehicle or BA (3, 10, and 30mg/kg) was administered intraperitoneally, 3 times (0, 24 and 48h) before CLP and CLP was done on 49(th)h of the study. Survival rate was observed till 120h post CLP. Lung tissues were collected for analysis by sacrificing mice 18h post CLP. BA at 10 and 30mg/kg dose significantly reduced sepsis-induced mortality and lung injury as implied by attenuated lung histopathological changes, decreased protein and neutrophils infiltration. BA also decreased lung NF-κB expression, cytokine, intercellular adhesion molecule-1, monocyte chemoattractant protein-1 and matrix metalloproteinase-9 levels. These evidences suggest that, the protective effects of BA on lungs are associated with defending action against inflammatory response and BA could be a potential modulatory agent of inflammation in sepsis-induced ALI.

Sputum neutrophil count after bronchial allergen challenge is related to peripheral blood neutrophil chemotaxis in asthma patients

OBJECTIVE

The aim of this study was to estimate relations between sputum neutrophilia and the chemotactic activity of peripheral blood neutrophils after the bronchial allergen challenge in asthma patients.

MATERIALS AND METHODS

Fifteen patients with allergic asthma (AA), 13 patients with allergic rhinitis (AR), all sensitized to Dermatophagoides pteronyssinus, and 8 healthy subjects (HS) underwent bronchial challenge with D. pteronyssinus. Sputum and peripheral blood collection were performed 24 h before, 7 and 24 h after the bronchial challenge. Cell counts were determined by the May-Grünwald-Giemsa method. Neutrophil chemotaxis was analyzed by a flow cytometer; IL-8 levels were measured by ELISA.

RESULTS

Sputum neutrophil count and peripheral blood neutrophil chemotaxis of patients with AA were greater 7 and 24 h after the challenge compared with the baseline values and patients with AR and HS (P < 0.05). Moreover, a significant correlation was found between the neutrophil count in sputum and IL-8 levels, and the chemotactic activity of peripheral blood neutrophils 24 h after the bronchial challenge only the patients with AA (P < 0.05).

CONCLUSIONS

Increased sputum neutrophil count was found to be associated with an enhanced chemotactic activity of peripheral blood neutrophils during allergen-induced late-phase airway inflammation in patients with allergic asthma.

Natural forms of vitamin E: metabolism, antioxidant, and anti-inflammatory activities and their role in disease prevention and therapy

The vitamin E family consists of four tocopherols and four tocotrienols. α-Tocopherol (αT) is the predominant form of vitamin E in tissues and its deficiency leads to ataxia in humans. However, results from many clinical studies do not support a protective role of αT in disease prevention in people with adequate nutrient status. On the other hand, recent mechanistic studies indicate that other forms of vitamin E, such as γ-tocopherol (γT), δ-tocopherol, and γ-tocotrienol, have unique antioxidant and anti-inflammatory properties that are superior to those of αT in prevention and therapy against chronic diseases. These vitamin E forms scavenge reactive nitrogen species, inhibit cyclooxygenase- and 5-lipoxygenase-catalyzed eicosanoids, and suppress proinflammatory signaling such as NF-κB and STAT3/6. Unlike αT, other vitamin E forms are significantly metabolized to carboxychromanols via cytochrome P450-initiated side-chain ω-oxidation. Long-chain carboxychromanols, especially 13'-carboxychromanols, are shown to have stronger anti-inflammatory effects than unmetabolized vitamins and may therefore contribute to the beneficial effects of vitamin E forms in vivo. Consistent with mechanistic findings, animal and human studies show that γT and tocotrienols may be useful against inflammation-associated diseases. This review focuses on non-αT forms of vitamin E with respect to their metabolism, anti-inflammatory effects and mechanisms, and in vivo efficacy in preclinical models as well as human clinical intervention studies.