Vitamin E down-modulates mitogen-activated protein kinases, nuclear factor-kappaB and inflammatory responses in lung epithelial cells

Synergistic Anti-Inflammatory Effects of Lipophilic Grape Seed Proanthocyanidin and Camellia Oil Combination in LPS-Stimulated RAW264.7 Cells

Combination drug therapy has become an effective strategy to control inflammation. Lipophilic grape seed proanthocyanidin (LGSP) and camellia oil (CO) have been independently investigated to show anti-inflammatory effects, but their synergistic anti-inflammatory effects are unknown. The aim of this study was to investigate the synergistic anti-inflammatory effects of LGSP and CO. The anti-inflammatory activity of LGSP and CO individual or in combination on RAW264.7 cells was detected by MTT assay, Griess reagent, RT-PCR, 2′,7′-dichlorfluoroescein diacetate and Western blot analysis. The combined treatment of LGSP with CO (20 μg/mL and 1 mg/mL) synergistically suppressed the production of NO, TNF-α, IL-6 and ROS. Further studies showed that the synergistic effect was attributed to their suppression of the activation of NF-κB and MAPK signaling pathways. Overall, our findings demonstrate the potential synergistic effect between LGSP and CO in LPS-induced inflammation.

Targeted antioxidants as therapeutics for treatment of pneumonia in the elderly

Community acquired pneumonia is a leading cause of mortality in the United States. Along with predisposing comorbid health status, age is an independent risk factor for determining the outcome of pneumonia. Research over the last few decades has contributed to better understanding the underlying immunodysregulation and imbalanced redox homeostasis tied to this aged population group that increases susceptibility to a wide range of pathologies. Major approaches include targeting oxidative stress by reducing ROS generation at its main sources of production which includes the mitochondrion. Mitochondria-targeted antioxidants have a number of molecular strategies that include targeting the biophysical properties of mitochondria, mitochondrial localization of catalytic enzymes, and mitigating mitochondrial membrane potential. Results of several antioxidant studies both in vitro and in vivo have demonstrated promising potential as a therapeutic in the treatment of pneumonia in the elderly. More human studies will need to be conducted to evaluate its efficacy in this clinical setting.

Could nanotechnology make vitamin E therapeutically effective?

Vitamin E (VitE) has important antioxidant and anti-inflammatory effects and is necessary for normal physiological function. α-Tocopherol (α-T), the predominant form of VitE in human tissues, has been extensively studied. Other VitE forms, particularly γ-tocopherol (γ-T), are also potent bioactive molecules. The effects are complex, involving both reactive oxygen and nitrogen species, but trials of VitE have been generally negative. We propose that a nanoparticle approach to delivery of VitE might provide effective delivery and therapeutic effect.

Fish oil and wheat-germ oil supplementation restores ovarian function in streptozotocin-diabetic rats

Diabetes is a chronic metabolic disorder and has a profound impact on women's reproductive health. This study aimed to investigate the protective effect of a mixture of fish oil (FO) and wheat-germ oil (WGO) on ovarian dysfunction in diabetic rats. Female Albino rats were divided into control, diabetic and FO-WGO-diabetic groups. Diabetes was induced by intraperitoneal injection of 65mgkg^-1 streptozotocin (STZ). Three weeks later, rats were given oral supplement of 0.4gkg^-1 oil mix (1000mg FO+100mg WGO) daily for 3 weeks. Antioxidant activity was assessed by measuring malondialdehyde (MDA) and reduced glutathione (GSH) levels, the GSH:oxidised glutathione (GSSG) ratio and superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) activities. Ovary function was indicated by serum concentrations of FSH, oestradiol (E₂), LH, anti-Müllerian hormone (AMH), ovary histopathology and follicle counts. Anti-inflammatory properties were detected by measuring nuclear factor (NF)-κB in follicular cells by immunohistochemistry. FO-WGO supplementation enhanced CAT, SOD and GPx activities and raised GSH levels and the GSH:GSSG ratio. Supplementation also increased FSH, E₂, LH and AMH levels and follicle counts. Moreover, NF-kB expression and MDA were reduced. These findings indicate that FO-WGO supplementation preserved ovarian function in STZ-induced diabetic rats.

Tocotrienols: the unsaturated sidekick shifting new paradigms in vitamin E therapeutics

Vitamin E family members: tocotrienols and tocopherols are widely known for their health benefits. Decades of research on tocotrienols have shown they have diverse biological activities such as antioxidant, anti-inflammatory, anticancer, neuroprotective and skin protection benefits, as well as improved cognition, bone health, longevity and reduction of cholesterol levels in plasma. Tocotrienols also modulate several intracellular molecular targets and, most importantly, have been shown to improve lipid profiles, reduce total cholesterol and reduce the volume of white matter lesions in human clinical trials. This review provides a comprehensive update on the little-known therapeutic potentials of tocotrienols, which tocopherols lack in a variety of inflammation-driven diseases.

Alleviation of 5-fluorouracil-induced intestinal mucositis in rats by vitamin E via targeting oxidative stress and inflammatory markers

BackgroundIntestinal mucositis is a major concern related with cancer therapy. It is well established that overproduction of reactive oxygen species and inflammatory mediators plays vital role in the pathogenesis of mucositis. The aim of the study was to investigate the modulatory effect of vitamin E (vit. E) on 5-fluorouracil (5-FU)-induced intestinal mucositis by targeting oxidative stress and inflammatory markers in rats. MethodsRats were randomly divided into four groups of six animals each. All four-group animals received normal standard diet and water throughout the experimental period which last up to 10 days. Rats were gavaged with vit. E (300 mg/kg b. wt.) daily for 10 days (day 1-10) and were given intraperitoneal injection of 5-FU (150 mg/kg b. wt.) or saline (control) on day 8 to induce mucositis. Results We found that vit. E supplementation ameliorated 5-FU-induced lipid peroxidation, myeloperoxidase activity, activation of nuclear factor κB, expression of cyclooxygenase-2, inducible nitric oxide synthase and mucin depletion. Vit. E administration also attenuated 5-FU-induced histological anomalies such as neutrophil infiltration, loss of cellular integrity, villus and crypt deformities. ConclusionsFindings of the study suggest that vit. E inhibits 5-FU-induced mucositis via modulation of oxidative stress, activation of redox sensitive transcription factor and its downstream targets.

Exosomes in immunoregulation of chronic lung diseases

Exosomes are nano-sized, membrane-bound vesicles released from cells that transport cargo including DNA, RNA, and proteins, between cells as a form of intercellular communication. In addition to their role in intercellular communication, exosomes are beginning to be appreciated as agents of immunoregulation that can modulate antigen presentation, immune activation, suppression, and surveillance. This article summarizes how these multifaceted functions of exosomes may promote development and/or progression of chronic inflammatory lung diseases including asthma, chronic obstructive pulmonary disease, and pulmonary fibrosis. The potential of exosomes as a novel therapeutic is also discussed.

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.

Mitochondria: a new therapeutic target in chronic kidney disease

Cellular metabolic changes during chronic kidney disease (CKD) may induce higher production of oxygen radicals that play a significant role in the progression of renal damage and in the onset of important comorbidities. This condition seems to be in part related to dysfunctional mitochondria that cause an increased electron "leakage" from the respiratory chain during oxidative phosphorylation with a consequent generation of reactive oxygen species (ROS). ROS are highly active molecules that may oxidize proteins, lipids and nucleic acids with a consequent damage of cells and tissues. To mitigate this mitochondria-related functional impairment, a variety of agents (including endogenous and food derived antioxidants, natural plants extracts, mitochondria-targeted molecules) combined with conventional therapies could be employed. However, although the anti-oxidant properties of these substances are well known, their use in clinical practice has been only partially investigated. Additionally, for their correct utilization is extremely important to understand their effects, to identify the correct target of intervention and to minimize adverse effects. Therefore, in this manuscript, we reviewed the characteristics of the available mitochondria-targeted anti-oxidant compounds that could be employed routinely in our nephrology, internal medicine and renal transplant centers. Nevertheless, large clinical trials are needed to provide more definitive information about their use and to assess their overall efficacy or toxicity.

α-Tocopherol long-chain metabolite α-13'-COOH affects the inflammatory response of lipopolysaccharide-activated murine RAW264.7 macrophages

SCOPE

Inflammatory response of macrophages is regulated by vitamin E forms. The long-chain metabolite α-13'-carboxychromanol (α-13'-COOH) is formed by hepatic α-tocopherol (α-TOH) catabolism and acts as a regulatory metabolite via pathways that are different from its metabolic precursor.

METHODS AND RESULTS

Using semisynthetically-derived α-13'-COOH we profiled its action on LPS-induced expression of pro- and anti-inflammatory genes using RT-qPCR and of key proteins by Western blotting. Effects on inflammatory response were assessed by measuring production of nitric oxide and prostaglandin (PG) E2 , PGD2 , and PGF2α. α-13'-COOH inhibits proinflammatory pathways in LPS-stimulated RAW264.7 macrophages more efficiently than α-TOH. Profiling inflammation-related genes showed significant blocking of interleukin (Il)1β by the metabolite and its precursor as well, while upregulation of Il6 was not impaired. However, induction of Il10, cyclooxygenase 2 (Cox2) and inducible nitric oxide synthase (iNos) by LPS and consequently the formation of nitric oxide and PG was significantly reduced by α-13'-COOH. Interestingly, α-13'-COOH acted independently from translocation of NFκB subunit p65.

CONCLUSION

Our study sheds new light on the mode of action of α-TOH on the inflammatory response in macrophages, which may be mediated in vivo at least in part by its metabolite α-13'-COOH. Our data show that α-13'-COOH is a potent anti-inflammatory molecule.

Moxifloxacin-loaded nanoemulsions having tocopheryl succinate as the integral component improves pharmacokinetics and enhances survival in E. coli-induced complicated intra-abdominal infection

In the present work, a novel nanoemulsion laden with moxifloxacin has been developed for effective management of complicated intra-abdominal infections. Moxifloxacin nanoemulsion fabricated using high pressure homogenization was evaluated for various pharmaceutical parameters, pharmacokinetics (PK) and pharmacodynamics (PD) in rats with E. coli-induced peritonitis and sepsis. The developed nanoemulsion MONe6 (size 168 ± 28 nm and zeta potential (ZP) 24.78 ± 0.45 mV, respectively) was effective for intracellular delivery and sustaining the release of MOX. MONe6 demonstrated improved plasma (AUC(MONe6/MOX) = 2.38-fold) and tissue pharmacokinetics of MOX (AUC(MONe6/MOX) = 2.63 and 1.47 times in lung and liver, respectively). Calculated PK/PD index correlated well with a reduction in bacterial burden in plasma as well as tissues. Enhanced survival on treatment with MONe6 (65.44%) and as compared to the control group (8.22%) was a result of reduction in lipid peroxidation, neutrophil migration, and cytokine levels (TNF-α and IL6) as compared to untreated groups in the rat model of E. coli-induced sepsis. Parenteral nanoemulsions of MOX hold a promising advantage in the therapy of E. coli-induced complicated intra-abdominal infections and is helpful in the prevention of further complications like septic shock and death.

Vitamin E-gene interactions in aging and inflammatory age-related diseases: implications for treatment. A systematic review

Aging is a complex biological phenomenon in which the deficiency of the nutritional state combined with the presence of chronic inflammation and oxidative stress contribute to the development of many age-related diseases. Under this profile, the free radicals produced by the oxidative stress lead to a damage of DNA, lipids and proteins with subsequent altered cellular homeostasis and integrity. In young-adult age, the cell has a complex efficient system to maintain a proper balance between the levels of free radicals and antioxidants ensuring the integrity of cellular components. In contrast, in old age this balance is poorly efficient compromising cellular homeostasis. Supplementation with Vitamin E can restore the balance and protect against the deteriorating effects of oxidative stress, progression of degenerative diseases, and aging. Experiments in cell cultures and in animals have clearly shown that Vitamin E has a pivotal role as antioxidant agent against the lipid peroxidation on cell membranes preserving the tissue cells from the oxidative damage. Such a role has been well documented in immune, endothelial, and brain cells from old animals describing how the Vitamin E works both at cytoplasmatic and nuclear levels with an influence on many genes related to the inflammatory/immune response. All these findings have supported a lot of clinical trials in old humans and in inflammatory age-related diseases with however contradictory and inconsistent results and even indicating a dangerous role of Vitamin E able to affect mortality. Various factors can contribute to all the discrepancies. Among them, the doses and the various isoforms of Vitamin E family (α,β,γ,δ tocopherols and the corresponding tocotrienols) used in different trials. However, the more plausible gap is the poor consideration of the Vitamin E-gene interactions that may open new roadmaps for a correct and personalized Vitamin E supplementation in aging and age-related diseases with satisfactory results in order to reach healthy aging and longevity. In this review, this peculiar nutrigenomic and/or nutrigenetic aspect is reported and discussed at the light of specific polymorphisms affecting the Vitamin E bioactivity.

Pesticide-induced decrease in rat testicular steroidogenesis is differentially prevented by lipoate and tocopherol

We have previously demonstrated that the sub-chronic administration of low doses of Toc or α-Toc, glyphosate and zineb to rats (i.p. 1/250 LD50, three times a week for 5 weeks) provoked severe oxidative stress (OS) in testicles. These effects were also reflected in plasma. Lipoic acid (LA) and α-tocopherol are considered as antioxidants due to their ability to neutralize reactive oxygenated species (ROS) and reset endogenous antioxidant levels. To investigate the possible protective effect on reproductive function, LA and Toc (i.p. 25, 50 and 100mg/kg) were administered simultaneously with the pesticide mixture (PM) for 5 weeks. Both drugs prevented OS and the damage to proteins and lipids caused by PM in a dose-dependent manner. The PM-induced increase levels of prostaglandins E2 and F2α was completely restored by LA but not by Toc. Similarly, only LA was able to restore the inhibition of testosterone production, the decrease of 3β- and 17β-hydroxysteroid dehydrogenases activities, and the elevation of gonatropins (FSH and LH) levels produced by PM. Furthermore, LA was more efficient than Toc in normalizing the histological alterations produced by PM administration, suggesting that pesticides act though other mechanisms that generate oxidative stress. In our experimental model LA displayed a higher protective role against pesticide-induced damage than that observed by Toc administration. Our results suggest that LA administration is a promising therapeutic strategy for coping with disorders suspected to be caused by OS generators - such as pesticides - in male reproductive system.

Oxidative stress: a pathogenic mechanism for Niemann-Pick type C disease

Niemann-Pick type C (NPC) disease is a neurovisceral atypical lipid storage disorder involving the accumulation of cholesterol and other lipids in the late endocytic pathway. The pathogenic mechanism that links the accumulation of intracellular cholesterol with cell death in NPC disease in both the CNS and the liver is currently unknown. Oxidative stress has been observed in the livers and brains of NPC mice and in different NPC cellular models. Moreover, there is evidence of an elevation of oxidative stress markers in the serumof NPC patients. Recent evidence strongly suggests that mitochondrial dysfunction plays an important role in NPC pathogenesis and that mitochondria could be a significant source of oxidative stress in this disease. In this context, the accumulation of vitamin E in the late endosomal/lysosomal compartments in NPC could lead to a potential decrease of its bioavailability and could be another possible cause of oxidative damage. Another possible source of reactive species in NPC is the diminished activity of different antioxidant enzymes. Moreover, because NPC is mainly caused by the accumulation of free cholesterol, oxidized cholesterol derivatives produced by oxidative stress may contribute to the pathogenesis of the disease.

Role of NADPH oxidase/ROS in pro-inflammatory mediators-induced airway and pulmonary diseases

Reactive oxygen species (ROS) are products of normal cellular metabolism and are known to act as second messengers. Under physiological conditions, ROS participate in maintenance of cellular 'redox homeostasis' in order to protect cells against oxidative stress. In addition, regulation of redox state is important for cell activation, viability, proliferation, and organ function. However, overproduction of ROS, most frequently due to excessive stimulation of either reduced nicotinamide adenine dinucleotide phosphate (NADPH) by pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) or the mitochondrial electron transport chain and xanthine oxidase, results in oxidative stress. Oxidative stress is a deleterious process that leads to airway and lung damage and consequently to several respiratory inflammatory diseases/injuries, including acute respiratory distress syndrome (ARDS), asthma, cystic fibrosis (CF), and chronic obstructive pulmonary disease (COPD). Many of the known inflammatory target proteins, such as matrix metalloproteinase-9 (MMP-9), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), cyclooxygenase-2 (COX-2), and cytosolic phospholipase A(2) (cPLA(2)), are associated with NADPH oxidase activation and ROS overproduction in response to pro-inflammatory mediators. Thus, oxidative stress regulates both key inflammatory signal transduction pathways and target proteins involved in airway and lung inflammation. In this review, we discuss mechanisms of NADPH oxidase/ROS in the expression of inflammatory target proteins involved in airway and lung diseases. Knowledge of the mechanisms of ROS regulation could lead to the pharmacological manipulation of antioxidants in airway and lung inflammation and injury.

Isoforms of vitamin E differentially regulate inflammation

Vitamin E regulation of disease has been extensively studied in humans, animal models and cell systems. Most of these studies focus on the α-tocopherol isoform of vitamin E. These reports indicate contradictory outcomes for anti-inflammatory functions of the α-tocopherol isoform of vitamin E, especially with regards to clinical studies of asthma and atherosclerosis. These seemingly disparate clinical results are consistent with recently reported unrecognized properties of isoforms of vitamin E. Recently, it has been reported that physiological levels of purified natural forms of vitamin E have opposing regulatory functions during inflammation. These opposing regulatory functions by physiological levels of vitamin E isoforms impact interpretations of previous studies on vitamin E. Moreover, additional recent studies also indicate that the effects of vitamin E isoforms on inflammation are only partially reversible using physiological levels of a vitamin E isoform with opposing immunoregulatory function. Thus, this further influences interpretations of previous studies with vitamin E in which there was inflammation and substantial vitamin E isoforms present before the initiation of the study. In summary, this review will discuss regulation of inflammation by vitamin E, including alternative interpretations of previous studies in the literature with regards to vitamin E isoforms.

A nutrient approach to prostate cancer prevention: The Selenium and Vitamin E Cancer Prevention Trial (SELECT)

The Selenium and Vitamin E Cancer Prevention Trial (SELECT) randomized 35,533 healthy men, >55 yr old (>50 yr if African American), with normal digital rectal exams and prostate specific antigens <4 ng/ml to 1) 200 μg/day l-selenomethionine, 2) 400 IU/day all-rac-alpha-tocopheryl acetate (vitamin E), 3) both supplements, or 4) placebo for 7 to 12 yr. The hypotheses underlying SELECT, that selenium and vitamin E individually and together decrease prostate cancer incidence, derived from epidemiologic and laboratory evidence and significant secondary endpoints in the Nutritional Prevention of Cancer (selenium) and Alpha-Tocopherol Beta-Carotene (vitamin E) trials. In SELECT, prostate cancer incidence did not differ among the 4 arms: hazard ratios [99% confidence intervals (CIs)] for prostate cancer were 1.13 (99% CI = 0.95-1.35, P = 0.06; n = 473) for vitamin E, 1.04 (99% CI = 0.87-1.24, P = 0.62; n = 432) for selenium, and 1.05 (99% CI = 0.88-1.25, P = 0.52; n = 437) for selenium + vitamin E vs. 1.00 (n = 416) for placebo. Statistically nonsignificant increased risks of prostate cancer with vitamin E alone [relative risk (RR) = 1.13, P = 0.06) and newly diagnosed Type 2 diabetes mellitus with selenium alone (RR = 1.07, P = 0.16) were observed. SELECT data show that neither selenium nor vitamin E, alone or together, in the doses and formulations used, prevented prostate cancer in this heterogeneous population of healthy men.

Signaling pathways involved in liver injury and regeneration in rabbit hemorrhagic disease, an animal model of virally-induced fulminant hepatic failure

Management of fulminant hepatic failure (FHF) continues to be one challenging problem, and experimental animal models resembling its clinical conditions are still needed. Rabbit hemorrhagic disease (RHD) fullfils many requirements of an animal model of FHF. This work investigated changes in MAPK, NF-kappaB, AP-1 and STAT pathways during RHD-induced liver injury. Rabbits were infected with 2 x 10(4) hemagglutination units of an RHD virus isolate. Apoptosis was documented by the presence of caspase-3 activity and substantial PARP proteolysis at 36 and 48 h postinfection (pi). Infection induced a marked and maintained expression of TNF-alpha from 12 h pi, while there was only a transitory increase in IL-6 expression. Expression of phosphorylated (p)-JNK, p-p38 and p-ERK1/2 was significantly elevated at 12 h pi. At 48 h pi p-JNK expression was maintained at a maximum level, while that of p-p38 returned to normality and there was no p-ERK1/2 expression. Activation of NF-kappaB and AP-1 and increased expression of VCAM-1 and COX-2 were observed. No significant changes were detected in activation of STAT1 and STAT3, while SOCS3 expression increased significantly. The current findings suggest that activation of JNK is an essential component in liver injury mediated by the RHD virus and that lack of activation of STAT3, probably mediated by SOCS3 over-expression, would contribute to the inhibition of the regenerative response. Data show the presence of molecular mechanisms contributing to liver damage and the lack of regeneration and they support the usefulness of this model to investigate novel therapeutical modalities in FHF.

The non-proteolytic house dust mite allergen Der p 2 induce NF-kappaB and MAPK dependent activation of bronchial epithelial cells

BACKGROUND

House dust mites (HDM) are well-known as a source of indoor aeroallergens and for causing allergic airway diseases. Some proteolytic HDM allergens are known to activate respiratory epithelial cells to produce pro-inflammatory mediators, while there is limited knowledge regarding such activity among non-proteolytic HDM allergens.

OBJECTIVE

To investigate whether Der p 2, a major non-proteolytic allergen of Dermatophagoides pteronyssinus, activates respiratory epithelial cells to produce mediators involved in asthma pathogenesis and to elucidate the mechanism of such activation.

METHODS

The human bronchial epithelial cell line BEAS-2B, normal human bronchial epithelial (NHBE) cells and the alveolar epithelial cell line A549 were exposed to recombinant Der p 2. Following exposure, we analysed a panel of soluble mediators and cell adhesion receptors involved in asthma pathogenesis by promoting recruitment, survival and binding of inflammatory cells. The involvement of nuclear factor (NF)-kappaB and mitogen-activated protein kinases (MAPKs) was studied using specific inhibitors.

RESULTS

Der p 2 activated bronchial BEAS-2B and NHBE cells, but not alveolar A549 cells. In BEAS-2B cells Der p 2 induced dose-dependent up-regulation in both mRNA level and protein secretion of granulocyte-macrophage colony-stimulating factor, IL-6, IL-8, monocyte-chemotactic protein-1 and macrophage inflammatory protein-3alpha. Secretion as well as surface expression of intercellular adhesion molecule (ICAM)-1 was also up-regulated, which was associated with increased adhesion of monocytes to the epithelial cells. The release of cytokines and chemokines was regulated by NF-kappaB and MAPK activation in different ways, while expression of ICAM-1 was solely dependent on NF-kappaB activation.

CONCLUSION

These results show that Der p 2 activates respiratory epithelial cells, indicating that this non-proteolytic allergen, in addition to its immunogenic properties, can aggravate respiratory airway disease by adjuvant-like activation of the lung epithelium.

Chemopreventive action of dexamethasone and alpha-tocopherol in oxidative stressed cells

INTRODUCTION

Recent research indicates a close connection of inflammation and cancer as presumed by Virchow in 1893. The growing understanding of cellular signalling and regulatory pathways reveals multiple links between inflammation and cancer. This study was designed to evaluate the influence of the anti-inflammatory drug dexamethasone and the antioxidant alpha-tocopherol on oxidative induced DNA damage, a major factor in the development of malignancies.

MATERIAL AND METHODS

Miniorgan cultures (MOC) of fresh biopsied human nasal mucosa were used to keep cells in their microenvironment and thus to mimic in vivo conditions. MOC were pretreated with dexamethasone and alpha-tocopherol in different concentrations on 1 or on 5 days before oxidative DNA damage was introduced by hydrogen peroxide. The effect of these substances on DNA damage was evaluated using the alkaline single cell microgel electrophoresis (Comet Assay).

RESULTS

Dexamethasone induced slight, but considerable DNA fragmentation by itself. It effectively protected cells from hydrogen peroxide induced DNA damage, leading to a maximum decrease of about 45% when preincubated on 5 days at 20 microM. alpha-Tocopherol most effectively reduced oxidative DNA fragmentation by about 38% when MOC were pretreated 5 days at 20 microM.

DISCUSSION

Our experimental data clearly shows the DNA protective action of dexamethasone and alpha-tocopherol with regard to oxidatively induced DNA damage, a major pathogenetic factor that inflammation and cancer have in common.

Rectal administration of d-alpha tocopherol for active ulcerative colitis: A preliminary report

AIM: To investigate the anti-oxidant and anti-neutrophil recruitment effects of rectal d-alpha (d-α) tocopherol administration on mild and moderately active ulcerative colitis (UC).

METHODS: Fifteen patients with mild and moderately active ulcerative colitis were enrolled in an open-label study of d-α tocopherol enema (8000 U/d) for 12 wk. All patients were receiving concomitant therapy with 5-aminosalicylic acid derivatives (5-ASA) and/or immunomodulator medications. Endoscopic evaluation was performed at baseline and after 4th and 12th weeks. Disease activity was measured with the Mayo disease activity index (DAI) and remission was defined as DAI of ≤ 2 with no blood in stool. Clinical response was defined as a DAI reduction of ≥ 2.

RESULTS: At the end of 12th week, the average DAI score significantly decreased compared to the beginning of the study (2.3 ± 0.37 vs 8 ± 0.48, P < 0.0001). One patient was withdrawn after 3 wk for being unavailable to follow-up. On the 4th week of therapy, 12 patients showed clinical response, 3 of whom (21.4%) achieving remission. After 12 wk, all 14 patients responded clinically to the therapy and remission was induced in 9 of them (64%). No patient reported adverse events or was hospitalized due to worsened disease activity.

CONCLUSION: This preliminary report suggests that rectal d-α tocopherol may represent a novel therapy for mild and moderately active UC. The observed results might be due to the anti-inflammatory and anti-oxidative properties of vitamin E.