Vitamin E deficiency induces liver nuclear factor-κB DNA-binding activity and changes in related genes

The Role of Vitamins in the Pathogenesis of Asthma

Vitamins play a crucial role in the proper functioning of organisms. Disturbances of their levels, seen as deficiency or excess, enhance the development of various diseases, including those of the cardiovascular, immune, or respiratory systems. The present paper aims to summarize the role of vitamins in one of the most common diseases of the respiratory system, asthma. This narrative review describes the influence of vitamins on asthma and its main symptoms such as bronchial hyperreactivity, airway inflammation, oxidative stress, and airway remodeling, as well as the correlation between vitamin intake and levels and the risk of asthma in both pre- and postnatal life.

Dietary Factors Associated with Asthma Development: A Narrative Review and Summary of Current Guidelines and Recommendations

Asthma is a complex disease, caused by a combination of genetic and environmental factors. The prevalence of asthma is increasing too rapidly to be attributable to genetic factors alone. Thus, environmental factors are becoming increasingly recognized as the cause of asthma. Modifying these environmental factors may be a simple approach for asthma prevention. To date, dietary intervention is an interesting modifiable factor because it can be implemented at the population level. The modification of systemic inflammation, oxidation, and microbial composition might be a mechanistic basis for prevention. This review summarizes the mechanistic basis and evidence from clinical studies on the association between dietary factors and asthma development. We also summarize the recommendations from many organizations and regional guidelines to assist the practicing physician to improve patient care.

Current treatment paradigms and emerging therapies for NAFLD/NASH

Non-alcoholic fatty liver disease (NAFLD) is one the fastest emerging manifestations of the metabolic syndrome worldwide. Non-alcoholic steatohepatitis (NASH), the progressive form of NAFLD, may culminate into cirrhosis and hepatocellular cancer (HCC) and is presently a leading cause of liver transplant. Although a steady progress is seen in understanding of the disease epidemiology, pathogenesis and identifying therapeutic targets, the slowest advancement is seen in the therapeutic field. Currently, there is no FDA approved therapy for this disease and appropriate therapeutic targets are urgently warranted. In this review we discuss the role of lifestyle intervention, pharmacological agents, surgical approaches, and gut microbiome, with regard to therapy for NASH. In particular, we focus the role of insulin sensitizers, thyroid hormone mimetics, antioxidants, cholesterol lowering drugs, incretins and cytokines as therapeutic targets for NASH. We highlight these targets aiming to optimize the future for NASH therapy.

Vitamin E supplementation strategies during feedlot receiving: effects on beef steer performance, antibody response to vaccination, and antioxidant defense1

This study utilized 204 Angus-based beef steers (249 ± 23 kg SD) from a single ranch with initial serum α-tocopherol concentrations of 3.9 ± 1.0 mg/L to determine the effect of varying doses of vitamin E (VE) on feedlot performance, antibody response to vaccination, and antioxidant defense. Seven days after arrival, steers were blocked by body weight and weaning protocol (preweaned, unweaned heavy, and unweaned light) and randomly assigned to pens within blocks (12 pens per block). Preweaned steers had been weaned for approximately 35 d prior to arrival, and unweaned steers were weaned when leaving the origin ranch. Pens within block were randomly assigned to supplemental VE (ROVIMIX E-50 Adsorbate, DSM Nutritional Products, Heerlen, The Netherlands) treatments (n = 9 pens per treatment): no supplemental VE (CON), 25 IU/kg dry matter (DM; LOW), 500 IU per steer daily (MED), or 1,000 IU per steer daily (HIGH). Back-calculated supplemental VE intake was 0, 151 (24.8 IU/kg DM), 484, and 995 IU/d for CON, LOW, MED, and HIGH, respectively. On day 6, all steers received a booster vaccine against bovine viral diarrhea virus (BVDV; Bovi-Shield Gold, One Shot, Zoetis, Parsippany, NJ). Steers were weighed on day -1, 0, 14, 26, and 27. One steer per pen representative of the average body weight of the pen was chosen as a sampling animal for blood (day -1, 6, 14, 26, and 28) and liver (day -3 and 24). Data were analyzed as a randomized complete block design using Proc Mixed of SAS with pen as the experimental unit and the fixed effects of treatment and block. Linear, quadratic, and cubic contrast statements were constructed using Proc IML; morbidity data were analyzed using Proc Glimmix. Day 24 liver and day 26 serum α-tocopherol concentrations were linearly increased by supplemental VE (P < 0.01). Supplemental VE did not affect DM intake, average daily gain, or gain:feed from day 0 to 27 (P ≥ 0.37), or the percentage of steers treated for respiratory disease (P ≥ 0.44). Day 24 liver glutathione concentrations decreased linearly due to supplemental VE (P ≤ 0.02). Total- and Mn-superoxide dismutase activities were quadratically affected by supplemental VE (P ≤ 0.07), with MED steers exhibiting the greatest activity. Over time, BVDV type 1 and 2 antibody titers numerically decreased, whereas the decrease in BVDV type 1 titers was lesser for HIGH steers (linear P = 0.04). Increasing doses of VE improved VE status but did not affect overall receiving period performance in steers with minimal to adequate VE status upon arrival.

Current Treatment of Nonalcoholic Fatty Liver Disease/Nonalcoholic Steatohepatitis

Treatment of nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH) is focused on patients with NASH because they are at highest risk for progressive liver disease. Current first-line treatment consists of lifestyle modifications. Patients should lose at least 7% to 10% of body weight via a combination of physical exercise and calorie restriction dieting. Surgical or endoscopic surgery for weight loss can be considered in obese patients, depending on degree of excess body weight and comorbidities. There is no currently approved pharmacotherapy for NASH. Vitamin E and pioglitazone have the most evidence of therapeutic efficacy but have limitations. The treatment modality chosen should be individualized.

Review article: novel methods for the treatment of non-alcoholic steatohepatitis - targeting the gut immune system to decrease the systemic inflammatory response without immune suppression

BACKGROUND

The systemic immune system plays a role in inflammation and fibrogenesis associated with non-alcoholic steatohepatitis (NASH) and has become a potential target for drug development. In particular, the gut immune system has been suggested as a means for generating signals that can target the systemic immune system.

AIM

To describe seven novel methods being developed for the treatment of NASH that target the gut immune system for alleviation of the systemic inflammatory response, including oral administration of fatty-liver-derived proteins, anti-CD3 antibodies, tumour necrosis factor fusion protein, anti-lipopolysaccharide antibodies, glucosylceramide, delayed-release mercaptopurine, and soy-derived extracts.

METHODS

A search for these methods for oral immunotherapy for NASH was conducted.

RESULTS

Oral administration of these compounds provides an opportunity for immune modulation without immune suppression, with the advantage of being independent of a single molecular/inflammatory pathway. These modes of oral immune therapy demonstrate superior safety profiles, such that the patient is not exposed to general immune suppression. Moreover, these approaches target the whole spectrum of the disease and may serve as adjuvants to other therapies, such that they provide a platform for treatment of concomitant disorders in patients with NASH, including diabetes and hyperlipidaemia. Most of the compounds reviewed are currently in phase II trials, and it is anticipated that the acquisition of more clinical data in the next few years will enable the use of this new class of drugs for the treatment of NASH.

CONCLUSION

Oral immunotherapy may provide a novel platform for the treatment of NASH.

Molecular basis of alcoholic fatty liver disease: From incidence to treatment

Alcoholic liver diseases have complex and multiple pathogenic mechanisms but still no effective treatment. Steatosis or alcoholic fatty liver disease (AFLD) has a widespread incidence and is the first step in the progression to more severe stages of alcoholic liver disease, with concomitant increases in morbidity and mortality rates. The ways in which this progression occurs and why some individuals are susceptible are still unanswered scientific questions. Research with animal models and clinical evidence have shown that it is a multifactorial disease that involves interactions between lipid metabolism, inflammation, the immune response and oxidative stress. Each of these pathways provides a better understanding of the pathogenesis of AFLD and contributes to the development of therapeutic strategies. This review emphasizes the importance of research on alcoholic steatosis based on incidence data, key pathogenic mechanisms and therapeutic interventions, and discusses perspectives on the progression of this disease.

Nonalcoholic fatty liver disease - current status and future directions

Nonalcoholic fatty liver disease (NAFLD) has emerged as the most common chronic liver disease worldwide with a reported prevalence ranging 6-33%, depending on the studied populations. It encompasses a spectrum of liver manifestations ranging from simple steatosis (also known as nonalcoholic fatty liver, NAFL) to nonalcoholic steatohepatitis (NASH), fibrosis and cirrhosis, which may ultimately progress to hepatocellular carcinoma. NAFLD is strongly associated with the components of metabolic syndrome, mainly obesity and type 2 diabetes mellitus. NAFLD patients are at increased risk of liver-related as well as cardiovascular mortality. Current paradigm suggests a benign course for NAFL whereas NASH is considered to be the progressive phenotype. Although previously under-recognized accumulating evidence suggests that NAFL may also progress, suggesting a higher number of patients at risk than previously appreciated. Liver biopsy remains the gold standard for definitive diagnosis, but the majority of patients can be diagnosed accurately by noninvasive methods. Approved therapies for NAFLD are still lacking and lifestyle modifications aiming at weight loss remain the mainstay of NAFLD treatment. Intensive research could identify insulin resistance, lipotoxicity and dysbiosis of the gut microbiota as major pathophysiological mechanisms, leading to the development of promising targeted therapies which are currently investigated in clinical trials. In this review we summarized the current knowledge of NAFLD epidemiology, natural history, diagnosis, pathogenesis and treatment and considered future directions.

Nonalcoholic fatty liver disease: new treatments

PURPOSE OF REVIEW

Nonalcoholic fatty liver disease is the most common cause of liver dysfunction in the western world because of its close association with obesity, insulin resistance and dyslipidaemia. Nonalcoholic steatohepatitis (NASH) is a particular health concern due to the increased morbidity and mortality associated with progressive disease. At present, without specific targeted pharmacological therapies, the mainstay of therapy remains weight loss through dietary modification and lifestyle change; thus, the purpose of this review is to summarize the recent evidence for current and emerging therapies in NASH.

RECENT FINDINGS

Some existing medications, including pioglitazones and angiotensin receptor antagonists, may be repurposed to help treat this condition. Vitamin E may improve histology in NASH, but safety issues limit its use. Recently, a number of novel agents specifically targeting nonalcoholic fatty liver disease pathogenesis have entered clinical trials, including the farnesoid X receptor agonist obeticholic acid, which has shown significant histological improvements in steatohepatitis and fibrosis.

SUMMARY

Diet/lifestyle modification remains the mainstay of treatment. For patients with NASH and advanced fibrosis, current liver-directed pharmacotherapy with vitamin E and pioglitazone offer some benefits; obeticholic acid appears promising and is currently being tested. Comorbidities must be diagnosed and treated; cardiovascular disease remains a primary cause of death in these patients.

Current efforts and trends in the treatment of NASH

Of all the aspects of non-alcoholic fatty liver disease (NAFLD), the slowest advances have occurred in the therapeutic field. Thirty-five years after its formal description and after 15 years of intense scrutiny from researchers worldwide, there is still no approved drug for the treatment of non-alcoholic steatohepatits (NASH). In the meantime, progress in the understanding of pathophysiology, diagnosis - both invasive and non-invasive, epidemiology and even natural history have been substantial or, at times, spectacular. In contrast, hepatitis C virus (HCV) therapy underwent constant improvement and even before the great acceleration of the past few years, patients were already being offered approved therapies that were increasingly more efficient. What then explains such a slow pace of therapeutic advances in NASH, and will this change in the near future? Here we will review commonly-held myths that have diverted attention from therapy of NASH, obstacles that have slowed down industrial development of drugs for this indication, and recent achievements that will create better conditions for drug development programs. We will also briefly review current knowledge of non-pharmacological and pharmacological management in this early era of NASH therapies.

Pharmacological agents for NASH

NASH is a common liver disease that increases liver-related mortality and reduces survival. The need for optimal management of NASH is therefore a priority for today's practicing hepatologist. The rationale for specific pharmacological therapy for NASH is based on the potential for disease progression and the difficulties that many patients have successfully implementing, in the long term, diet and lifestyle changes. Even in those that succeed, limited evidence exists that severe liver injury in patients with NASH can be reversed by diet and lifestyle measures alone. This Review provides a personal and critical assessment of the histological efficacy and safety of agents tested in randomized trials in patients with NASH.

Terpenic fraction of Pterodon pubescens inhibits nuclear factor kappa B and extracellular signal-regulated protein kinase 1/2 activation and deregulates gene expression in leukemia cells

Background

Plant derived compounds have been shown to be important sources of several anti-cancer agents. As cell cycle deregulation and tumor growth are intimately linked, the discovery of new substances targeting events in this biochemical pathway would be of great value. The anti-leukemic effect of an ethanolic extract of Pterodon pubescens seeds (EEPp) has been previously demonstrated and now we show that a terpenic subfraction (SF5) of EEPp containing farnesol, geranylgeraniol and vouacapan derivatives induces apoptosis in the human chronic myelogenous leukemia cell line K562. This work addresses SF5’s antiproliferative mechanisms in these cells since they are still unclear.

Methods

DNA synthesis in K562 cells was assessed by [³H]-methyl-thymidine incorporation and cell cycle status by flow cytometry. The expression of cyclins D1 and E2, of the cell cycle inhibitor p21 and of the proto-oncogene c-myc was evaluated by semi-quantitative RT-PCR. Extracellular-signal-regulated kinases (ERK) 1/2 and nuclear factor kappa B (NF-κB) activation was evaluated by western blotting.

Results

In K562 cells, SF5 treatment induced a higher inhibition of DNA synthesis and cell growth than the original EEPp hexanic fraction from which SF5 originated, and also arrested the cell cycle in G1. Exposure of these cells to SF5 led to a decrease in cyclin E2 and c-myc expression while p21 mRNA levels were increased. Furthermore, SF5 inhibited the activation of mitogen-activated protein kinase (MAPK) ERK 1/2 and NF-κB.

Conclusions

This work suggests that the anti-leukemic action of SF5 is linked to the inhibition of ERKs, NF-κB and c-myc signaling pathways resulting in reduced cyclin E2 mRNA expression and cell cycle arrest in the G1 phase.

Fat-soluble vitamins and atopic disease: what is the evidence?

The prevalence of asthma and other atopic disorders continues to increase worldwide. Examination of the epidemiologic patterns has revealed that this rise has occurred primarily in western, industrialised countries and countries transitioning to this lifestyle. While many changes have occurred in human populations over the years, it has been hypothesised that some of the relevant changes that have led to the rise in asthma and atopic disorders have been the changes from a traditional diet to a more western diet consisting of decreased intake of fruits and vegetables (sources of antioxidant vitamins and carotenoids) leading to decreased intakes of vitamins E and A, and a decrease in sun exposure (e.g. greater time spent indoors and heavy use of sunscreen) leading to decreased circulating levels of vitamin D. This review will examine the evidence for an effect of fat-soluble vitamins (vitamins A, D and K) on the development and severity of asthma and allergies. While observational studies suggest that these vitamins may play a salutary role in asthma and allergies, large, well-designed clinical trials are lacking. Of the fat-soluble vitamins, vitamin D holds great promise as an agent for primary and secondary prevention of disease. Ongoing clinical trials will help determine whether results of observational studies can be applied to the clinical setting.

Influence of dietary antioxidants and fatty acids on neutrophil mediated bacterial killing and gene expression in healthy Beagles

Dietary (n-3) fatty acids from fish oil have been used to modulate immune function in many mammalian species. Together, dietary antioxidants and behavioral enrichment have been shown to enhance neutrophil phagocytosis in geriatric Beagle dogs. The purpose of this study was to further investigate the effects of vitamins E and C, in combination with dietary fish oil, on neutrophil mediated bacterial killing, and on transcript levels of selected neutrophil mRNA. Fifty adult Beagle dogs were randomized into five dietary treatment groups for 60 days. All foods were complete and balanced and met the nutrient profiles of AAFCO for adult dogs. For 60 days before study initiation, dogs consumed a pretrial food that contained 74 IU/kg vitamin E and 0 mg/kg vitamin C. The five experimental foods were confirmed by analytical methods to contain ≥640 IU/kg vitamin E and 130 mg/kg vitamin C (as fed). Experimental foods ranged from low levels of EPA and DHA (pretrial food and lowest experimental food had 0.01% EPA and no detectable DHA) to the highest experimental food with 0.25% EPA and 0.17% DHA. Ex vivo bactericidal activity of activated, peripheral-blood neutrophils against Lactococcus lactis was determined after 1 h incubation. Bactericidal activity was calculated as a percentage of control values (bacteria incubated in media without neutrophils). Transcript levels of genes involved in neutrophil-mediated immune functions were determined by real-time qPCR. Dogs in all treatment groups had increased serum vitamin E concentration (P<0.01). After consuming experimental food for 60 days, neutrophils from dogs in all 5 treatment groups also had increased bactericidal activity (P<0.01). Dietary fish oil however, had no effect on bactericidal activity. Stepwise multiple regression analysis demonstrated that the change in neutrophil mediated bacterial killing was significantly correlated to changes in gene expression of interleukin-8 receptor (IL-8R), interleukin converting enzyme (ICE), and myeloperoxidase (MPO; r(2)=0.33; P=0.003). When stepwise multiple regression analysis was performed considering each mRNA as a dependent variable and change in selected individual and summed fatty acid concentrations as independent variables, change in the ratio of saturated fatty acids (SFA) to polyunsaturated fatty acids (PUFA) was significant (P≤0.05) in the mRNA regression analyses for IL-8R, ICE, MPO, and cyclooxygenase-2. In summary, circulating neutrophils from dogs fed diets enriched in vitamins E and C had significantly increased bactericidal activity as well as altered gene expression. Change in SFA to PUFA ratio also altered neutrophil gene expression.

Dietary vitamin E deficiency does not affect global and specific DNA methylation patterns in rat liver

The aim of the present study was to determine the effects of a 6-month dietary vitamin E (VE) deficiency on DNA methylation and gene expression in rat liver. Two enzymes, 5-α-steroid reductase type 1 (SRD5A1) and the regulatory subunit of γ-glutamylcysteinyl synthetase (GCLM), which are differentially expressed on the mRNA level, were analysed for promoter methylation in putative cytosine-phospho-guanine (CpG) island regions located at the 5′ end using base-specific cleavage and matrix-assisted laser desorption ionisation time-of-flight MS. A twofold increase in the mRNA level of SRD5A1 gene and a twofold decrease in the mRNA level of GCLM gene in VE-deficient animals were not associated with different CpG methylation of the analysed promoter region. Furthermore, global DNA methylation was not significantly different in these two groups. Thus, the present results indicate that the VE-induced regulation of SRD5A1 and GCLM in rat liver is not directly mediated by changes in promoter DNA methylation.

Modulation of ozone-sensitive genes in alpha-tocopherol transfer protein null mice

Alpha-tocopherol transfer protein (ATTP) null mice (ATTP-/-) have a systemic alpha-tocopherol (AT) deficiency, with their lung AT levels being < 10% of those in AT-replete ATTP(+/+) mice when fed a standard rodent chow diet. ATTP(+/+) and ATTP(-/-) mice (4 wk old male mice, n = 16 per group) were fed a standard diet (35 IU AT/kg diet) for 8-12 wk, exposed 6 h/day for 3 days to either to O(3) (0.5 ppm) or filtered air, then sacrificed. No significant differences in plasma or lung AT concentrations were observed in response to this level of O(3) exposure. Lung genomic responses of the lungs to O(3) were determined using Affymetrix 430A 2.0 arrays containing over 22,600 probe sets representing 14,000 well-characterized mouse genes. As compared with filtered air exposure, O(3) exposure resulted in 99 genes being differentially expressed in ATTP(-/-) mice, as compared to 52 differentially expressed genes in ATTP(+/+) mice. The data revealed an O(3)-induced upregulation of genes related to cell proliferation/DNA repair and inflammatory-immune responses in both ATTP(+/+) and ATTP(-/-) mice, with the expression of 22 genes being common to both, whereas 30 and 77 genes were unique to ATTP(+/+) and ATTP(-/-) mice, respectively. The expressions of O(3) sensitive genes-Timp1, Areg, Birc5 and Tnc-were seen to be further modulated by AT status. The present study reveals AT modulation of adaptive response of lung genome to O(3) exposure.

Vitamin-regulated cytokines and growth factors in the CNS and elsewhere

There is a growing awareness that natural vitamins (with the only exception of pantothenic acid) positively or negatively modulate the synthesis of some cytokines and growth factors in the CNS, and various mammalian cells and organs. As natural vitamins are micronutrients in the human diet, studying their effects can be considered a part of nutritional genomics or nutrigenomics. A given vitamin selectively modifies the synthesis of only a few cytokines and/or growth factors, although the same cytokine and/or growth factor may be regulated by more than one vitamin. These effects seem to be independent of the effects of vitamins as coenzymes and/or reducing agents, and seem to occur mainly at genomic and/or epigenetic level, and/or by modulating NF-kappaB activity. Although most of the studies reviewed here have been based on cultured cell lines, but their findings have been confirmed by some key in vivo studies. The CNS seems to be particularly involved and is severely affected by most avitaminoses, especially in the case of vitamin B(12). However, the vitamin-induced changes in cytokine and growth factor synthesis may initiate a cascade of events that can affect the function, differentiation, and morphology of the cells and/or structures not only in the CNS, but also elsewhere because most natural vitamins, cytokines, and growth factors cross the blood-brain barrier. As cytokines are essential to CNS-immune and CNS-hormone system communications, natural vitamins also interact with these circuits. Further studies of such vitamin-mediated effects could lead to vitamins being used for the treatment of diseases which, although not true avitaminoses, involve an imbalance in cytokine and/or growth factor synthesis.

Severe vitamin E deficiency modulates airway allergic inflammatory responses in the murine asthma model

Allergic asthma is a complex immunologically mediated disease associated with increased oxidative stress and altered antioxidant defenses. It was hypothesized that alpha-tocopherol (alpha-T) decreases oxidative stress and therefore its absence may influence allergic inflammatory process, a pathobiology known to be accompanied by oxidative stress. Therefore, selected parameters of allergic asthma sensitization and inflammation were evaluated following ovalbumin sensitization and re-challenge of alpha-T transfer protein (TTP) knock-out mice (TTP(-/-)) that have greatly reduced lung alpha-T levels (e.g.<5%) compared to their litter mate controls (TTP(+/+)). Results showed that severe alpha-T deficiency result in a blunted lung expression of IL-5 mRNA and IL-5 protein and plasma IgE levels compared with TTP(+/+) mice following immune sensitization and rechallenge, although lung lavage eosinophil levels were comparable in both genomic strains. It is concluded that the initial stimulation of immune responses by the TTP(-/-) mice were generally blunted compared to the TTP(+/+) mice, thus diminishing some aspects of subsequent allergic inflammatory processes.

Hepatocyte-specific c-Met deletion disrupts redox homeostasis and sensitizes to Fas-mediated apoptosis

The hepatocyte growth factor and its receptor c-Met direct a pleiotropic signal transduction pathway that controls cell survival. We previously demonstrated that mice lacking c-Met (Met-KO) in hepatocytes were hypersensitive to Fas-induced liver injury. In this study, we used primary hepatocytes isolated from Met-KO and control (Cre-Ctrl) mice to address more directly the protective effects of c-Met signaling. Loss of c-Met function increased sensitivity to Fas-mediated apoptosis. Hepatocyte growth factor suppressed apoptosis in Cre-Ctrl but not Met-KO hepatocytes concurrently with up-regulation of NF-kappaB and major antiapoptotic proteins Bcl-2 and Bcl-xL. Intriguingly, Met-KO hepatocytes exhibited intrinsic activation of NF-kappaBas well as Bcl-2 and Bcl-xL. Furthermore, unchallenged Met-KO cells displayed oxidative stress as evidenced by overproduction of reactive oxygen species, which was associated with greater NADPH and Rac1 activities, was blocked by the known NADPH oxidase inhibitors, and was paralleled by increased lipid peroxidation and reduced glutathione (GSH) content. N-Acetylcysteine, an antioxidant and GSH precursor, significantly reduced Jo2-induced cell death. Conversely, the GSH-depleting agent buthionine sulfoximine completely abolished the protective effects of N-acetylcysteine in Met-KO hepatocytes. In conclusion, genetic inactivation of c-Met in mouse hepatocytes caused defects in redox regulation, which may account for the increased sensitivity to Fas-induced apoptosis and adaptive up-regulation of NF-kappaB survival signaling. These data provide evidence that intact c-Met signaling is a critical factor in the protection against excessive generation of endogenous reactive oxygen species.

Subcutaneous vitamin E ameliorates liver injury in an in vivo model of steatocholestasis

Several genetic metabolic liver diseases share the pathological features of combined steatosis and cholestasis, or steatocholestasis. The aims of this study were to develop and characterize an in vivo model for steatocholestasis and to evaluate the effects of an antioxidant treatment on liver injury, oxidative stress, and mitochondrial perturbations in this model. Obese and lean Zucker rats received intravenous (IV) injections of glycochenodeoxycholic acid (GCDC) and were killed 4 hours later. Liver enzymes were measured; the liver histology was assessed, and hepatic mitochondria were analyzed for mitochondrial lipid peroxidation. In separate experiments, rats received daily injections of subcutaneous (SQ) vitamin E before GCDC infusion. Bile acid-induced injury (serum AST and ALT and liver histology) was more severe in the obese rats than in the lean rats, characterized predominantly by extensive cell necrosis with minimal evidence of apoptosis. SQ vitamin E provided significant protection against IV GCDC-induced hepatic injury, in vitro GCDC-induced permeability transition, and cytochrome C and apoptosis-inducing factor release from isolated mitochondria.

CONCLUSION

Steatosis sensitizes the liver to bile acid-induced necrotic hepatocyte injury, which is responsive to vitamin E therapy.

Changes in plasma alpha and gamma tocopherol levels before and after long-term local hyperthermia in cancer patients

Local hyperthermia is one of the heat therapies for cancer patients. The effect of this therapy is recognized to affect the immune function. On the other hand, researchers have recently suggested that vitamin E has not only antioxidant but also other functions including the immune function. However, the association between local hyperthermia therapy and vitamin E level is not yet well understood. Comparing plasma alpha and gamma tocopherol levels before and after the therapy, the basal levels of both tocopherols in the cancer patients did not significantly differ from those in healthy subjects. However, the interindividual difference in the basal levels was very wide in the cancer patients. After long-term local hyperthermia (more than 70 days), the levels of both tocopherols were significantly higher than the basal levels. This result suggests that long-term local hyperthermia therapy influences plasma tocopherol level in cancer patients; thus, an increase in vitamin E level may play an important role in the therapy of cancer patients.

The Roles of α‐Vitamin E and Its Analogues in Prostate Cancer

Prostate cancer is the second most commonly diagnosed cancer and the third leading fatal cancer in American men. Comprehensive studies from human epidemiological studies, animal tumor models, and cellular molecular levels suggested that alpha-vitamin E and its derivatives possess remarkable chemopreventive and chemotherapeutic against prostate cancer. This chapter details the facts of alpha-vitamin E and its nonantioxidant functions in prostate cancer, focuses on the biological mechanisms for the alpha-vitamin E and its ester analogue, alpha-vitamin E succinate (VES), in prevention and therapy of prostate cancer, and raises specific questions that remain for intensive investigation in the future.

Vitamin E and NF‐κB Activation: A Review

Nuclear factor (NF-kappaB)(1) is a eukaryotic transcription factor that may be activated by oxidative stress. Because of this hypothesis, the effect of vitamin E on NF-kappaB activation has been examined in many studies, using both in vivo and in vitro models. Most of these studies have observed that vitamin E inhibits the activation of NF-kappaB, with the greatest inhibition seen with the succinate form. Vitamin E may be inhibiting NF-kappaB by reducing oxidative stress or through one of its nonantioxidant functions; this is not clear at the present time. It also is not known if the inhibition of NF-kappaB is necessary for any of vitamin E's effects on gene expression and the resulting physiological effects.