Preconception serum lipids and lipophilic micronutrient levels are associated with live birth rates after IVF

RESEARCH QUESTION

Is a mixture of preconception serum lipids and lipophilic micronutrients associated with clinical pregnancy and live births?

DESIGN

In this prospective cohort study, blood serum was collected on the day of oocyte retrieval for 180 women undergoing IVF at an academic reproductive health centre. Concentrations of lipids (phospholipids, total cholesterol, high- and low-density lipoproteins, and triglycerides) and lipophilic micronutrients (α-, δ-, and γ-tocopherols, retinol, β- and α-carotenes, β-cryptoxanthin, lutein and lycopene) were determined using diagnostic reagent kits and high-performance liquid chromatography. Poisson regression was used with robust variance estimation to evaluate changes in Z-scores for the mixture of serum lipid and lipophilic micronutrient concentrations as predictors of embryo implantation, clinical pregnancy and live birth, adjusted for age, body mass index (BMI), race, smoking status, infertility diagnosis, ovarian stimulation protocol and other measured lipid and lipophilic micronutrient concentrations.

RESULTS

Each SD higher serum triglyceride concentration was associated with a lower chance of live birth (RR 0.54; 95% CI 0.33 to 0.90) whereas a 1 SD higher serum α-tocopherol concentration, as part of a mixture of serum lipids and lipophilic micronutrients, was associated with a higher likelihood for a live birth (RR 1.61; 95% CI 1.11 to 2.36). Serum β-carotene concentrations were associated with live birth in a non-linear fashion; low β-carotene was associated with a lower chance of live birth and high β-carotene with a higher chance of live birth.

CONCLUSION

Although components of a mixture of lipids and lipophilic micronutrients were associated with live birth outcomes after IVF, a larger investigation is necessary to fully evaluate the potential clinical implications.

A new alternative insight of nanoemulsion conjugated with κ-carrageenan for wound healing study in diabetic mice: In vitro and in vivo evaluation

Astaxanthin and alpha-tocopherol have attracted great attention because of their properties for the management of wound healing in diabetics. This study aimed to investigate the wound healing study of astaxanthin and alpha-tocopherol with κ-carrageenan nanoemulsion (AS-TP@KCNE) and to perform a histopathological study on streptozotocin (STZ)-induced diabetic mice. AS-TP@KCNE were also evaluated with aim of maintaining an effective and prolonged antidiabetic potential. KC@SENE and KC@USNE were obtained by spontaneous and ultrasonication emulsification methods and were characterized for stability, pH, particle size, and zeta potential by standard analysis. In vitro cytotoxicity and wound healing results demonstrated less toxicity and faster cell migration for the nanoemulsions at different concentrations. Based on the promising results, transdermal administration of AS-TP@KCNE can significantly restore the body weight, reduce fasting blood glucose levels, and improve glucose tolerance, which improved the ability to quickly heal of wounds in diabetic mice compared to control. In conclusion, the present study shows that the AS-TP@KCNE are biocompatible and possess healing properties that accelerate wound closure and exhibited better control of hyperglycemia and more superbly reversed the diabetes mellitus complications than STZ-induced diabetic mice. These results suggested that AS-TP@KCNE could be a promising platform for wound healing applications for diabetics.

Inhibition of Osteocyte Membrane Repair Activity via Dietary Vitamin E Deprivation Impairs Osteocyte Survival

Osteocytes experience plasma membrane disruptions (PMD) that initiate mechanotransduction both in vitro and in vivo in response to mechanical loading, suggesting that osteocytes use PMD to sense and adapt to mechanical stimuli. PMD repair is crucial for cell survival; antioxidants (e.g., alpha-tocopherol, also known as Vitamin E) promote repair while reactive oxygen species (ROS), which can accumulate during exercise, inhibit repair. The goal of this study was to determine whether depleting Vitamin E in the diet would impact osteocyte survival and bone adaptation with loading. Male CD-1 mice (3 weeks old) were fed either a regular diet (RD) or Vitamin E-deficient diet (VEDD) for up to 11 weeks. Mice from each dietary group either served as sedentary controls with normal cage activity, or were subjected to treadmill exercise (one bout of exercise or daily exercise for 5 weeks). VEDD-fed mice showed more PMD-affected osteocytes (+ 50%) after a single exercise bout suggesting impaired PMD repair following Vitamin E deprivation. After 5 weeks of daily exercise, VEDD mice failed to show an exercise-induced increase in osteocyte PMD formation, and showed signs of increased osteocytic oxidative stress and impaired osteocyte survival. Surprisingly, exercise-induced increases in cortical bone formation rate were only significant for VEDD-fed mice. This result may be consistent with previous studies in skeletal muscle, where myocyte PMD repair failure (e.g., with muscular dystrophy) initially triggers hypertrophy but later leads to widespread degeneration. In vitro, mechanically wounded MLO-Y4 cells displayed increased post-wounding necrosis (+ 40-fold) in the presence of H₂O₂, which could be prevented by Vitamin E pre-treatment. Taken together, our data support the idea that antioxidant-influenced osteocyte membrane repair is a vital aspect of bone mechanosensation in the osteocytic control of PMD-driven bone adaptation.

The Effect of Alpha-Tocopherol on Morphine Tolerance-induced Expression of c-fos Proto-oncogene from a Biotechnological Perspective

BACKGROUND

The increase of oxidant compounds is the most well-known reasons for the tolerance to the analgesic properties of Morphine. Additionally, the production of proxy-nitrite impairs receptors, proteins and enzymes involved in the signaling pathways of analgesia, apoptosis and necrosis. Also, we revised all patents relating to opioid tolerance control methods.

OBJECTIVE

The aim of this study was to assess the effects of Alpha-tocopherol as an anti-oxidant agent to reduce Morphine tolerance.

METHOD

Forty male rats randomly divided into four groups. 10 mg/kg of morphine was injected subcutaneously to create the desired level of tolerance. After modeling, 70 mg/kg Alpha- Tocopherol was injected intraperitoneal. Also, the hot plate recorded pain threshold alterations was used to evaluate the behavioral test. All tissue samples were extracted from the spinal cord, thalamus and frontal cortex for molecular and gene expression evaluations. Also, the effect of Alpha- Tocopherol on the apoptosis and necrosis parameters was analyzed using nissl staining and tunel test.

RESULTS

The time latency results showed that there were no significant differences in the different days in groups treated with Morphine plus Alpha-Tocopherol. However, our data highlighted that the pain threshold and their time latency in respond to it had substantially increased in comparison with the control group. Furthermore, we found that the Alpha-Tocopherol obviously decreased c-fos gene expression, especially in the spinal cord.

CONCLUSION

Thus, co-administration of Alpha-Tocopherol with Morphine can decrease the adverse effects of nitrite proxy, which is released due to repeated injections of Morphine.

Neurocognitive effects of an omega-3 fatty acid and vitamins E+C in schizophrenia: A randomised controlled trial

There is need for more efficient treatment of neurocognitive deficits in schizophrenia. In this 16 weeks randomised, placebo-controlled trial, we examined neurocognitive effects of adding ethyl-eicosapentaenoate 2g/day and/or vitamins E 364mg/day + C 1000mg/day to antipsychotics in 53 patients aged 18-39 years with acute schizophrenia. For the sake of validating neurocognitive tests, healthy subjects, not taking trial drugs, were also included in the study. Ethyl-EPA given alone to patients with low baseline RBC polyunsaturated fatty acids (PUFA), and Vitamins E+C given alone to high PUFA patients, impaired sustained attention (Continuous Performance Test, CPT-IP d prime score), standardised effect sizes d = 0.78 and d = 0.69, respectively. These adverse effects were paralleled by excessive increases in long-chain PUFA and serum alpha-tocopherol, respectively. They were counteracted by combining ethyl-EPA and vitamins, d = 0.80 and d = 0.74 in low and high PUFA patients, respectively. No other neurocognitive tests yielded significant results. Plausible mechanisms of harmful effects are oxidative stress and lipid raft disruption.

Molecular mechanisms of neuroprotective effect of adjuvant therapy with phenytoin in pentylenetetrazole-induced seizures: Impact on Sirt1/NRF2 signaling pathways

Current anticonvulsant therapies are principally aimed at suppressing neuronal hyperexcitability to prevent or control the incidence of seizures. However, the role of oxidative stress processes in seizures led to the proposition that antioxidant compounds may be considered as promising candidates for limiting the progression of epilepsy. Accordingly, the aim of this study is to determine if coenzyme Q10 (CoQ10) and alpha-tocopherol (α-Toc) have a neuroprotective effect in rats against the observed oxidative stress and inflammation during seizures induced by pentylenetetrazole (PTZ) in rats, and to study their interactions with the conventional antiseizure drug phenytoin (PHT), either alone or in combination. Overall, the data revealed that α-Toc and CoQ10 supplementation can ameliorate PTZ-induced seizures and recommended that nuclear factor erythroid 2-related factor 2 (NRF2) and silencing information regulator 1 (Sirt1) signaling pathways may exemplify strategic molecular targets for seizure therapies. The results of the present study provide novel mechanistic insights regarding the protective effects of antioxidants and suggest an efficient therapeutic strategy to attenuate seizures. Additionally, concurrent supplementation of CoQ10 and α-Toc may be more effective than either antioxidant alone in decreasing inflammation and oxidative stress in both cortical and hippocampal tissues. Also, CoQ10 and α-Toc effectively reverse the PHT-mediated alterations in the brain antioxidant status when compared to PHT only.

Methylmercury alters the number and topography of NO-synthase positive neurons in embryonic retina: Protective effect of alpha-tocopherol

Vertebrate retina has been shown to be an important target for mercury toxicity and very studies have shown the effect of mercury on the retinal ontogenesis. The nitrergic system plays an important role in the retinal development. The current work studied the effects of methylmercury (MeHg) exposure on the NO-synthase positive neurons (NADPH-diaphorase neurons or NADPH-d+) of the chick retinal ganglion cell layer at embryonic E15 and postnatal P1 days. Retinal flat mounts were stained for NADPH-diaphorase histochemistry and mosaic properties of NADPH-d + were studied by plotting isodensity maps and employing density recovery profile technique. It was also evaluated the protective effect of alpha-tocopherol treatment on retinal tissues exposed to MeHg. MeHg exposure decreased the density of NADPH-d + neurons and altered cell mosaic properties at E15 but had very little or no effect at P1 retinas. Alpha-tocopherol has a protective effect against MeHg exposure at E15. MeHg alterations and alpha-tocopherol protective effect in embryonic retinas were demonstrated to be at work in experimental conditions. MeHg effect in the early phases of visual system development in natural conditions might use the nitrergic pathway and supplementary diet could have a protective effect. At later stages, this mechanism seems to be naturally protected.

Hepatoprotective effects of capsaicin and alpha-tocopherol on mitochondrial function in mice fed a high-fat diet

Capsaicin (CAP) and alpha-tocopherol (TOC) have antioxidant properties. We investigated effects of CAP and TOC on mitochondrial oxidative stress and mitochondrial bioenergetics in liver of mice fed HFD. AST, ALT, glucose, homeostasis model assessment-insulin resistance index ((HOMA-IR)) and mitochondrial oxidative stress parameters increased, whereas oxidative phosphorylation (OXPHOS) enzymes, tricarboxylic acid cycle (TCA) enzymes, ATP level and mitochondrial metabolic function (MTT) decreased in mice fed a HFD compared to the fed a standard diet (NC). Treatment of HFD together with CAP (HFC group), TOC (HFT group) or TOC and CAP (HCT group) can ameliorate the examined parameters. Because co-treatment with CAP and TOC displayed a better ameliorating effect on liver redox status and mitochondrial bioenergetics functions, they can be useful to protect against HFD and oxidative stress-related in liver diseases.

Effect of different antioxidants on reversing compromised resin bond strength after enamel bleaching: An in vitro study

OBJECTIVE

The effect of 10% sodium ascorbate, 10% α-tocopherol, 10% grape seed extract, and 10% guava seed extract solutions on the shear bond strength (SBS) of composite resin to bleached enamel was evaluated.

MATERIALS AND METHODS

Labial enamel surfaces of 72 extracted maxillary central incisors were bleached using 37.5% hydrogen peroxide. Sixty-four specimens were divided into four experimental groups (Group I-IV) comprising 16 specimens each and remaining eight specimens were placed in Group V. Groups I-IV were further divided into 2 subgroups: A (10 min) and B (120 min) comprising 8 specimens each. Eight unbleached specimens served as control (Group VI). Immediately following bleaching, Groups IA-IVA and IB-IVB specimens were treated with respective antioxidants for 10 min and 120 min. All specimens were then bonded with composite resin. Specimens were stored in distilled water for 24 h. SBS testing was done. Data were tabulated and subjected to statistical analysis using ANOVA and Tukey's honest significant difference test.

RESULTS

Group VI (unbleached) showed the highest SBS followed by Group IV (10% guava seed extract).

CONCLUSION

Use of antioxidants effectively reversed the compromised bond strength of bleached enamel. About 10% guava seed extract application after bleaching showed best bond strength.

Component analysis of nutritionally rich chloroplasts: recovery from conventional and unconventional green plant species

A study of the literature indicates that chloroplasts synthesise a range of molecules, many of which have nutritional value for humans, but the nutritional credentials of chloroplasts recovered from plant cells are not established. Chloroplast-rich-fractions (CRFs) were prepared from green plant species and the macro- and micro-nutrient composition compared with the whole leaf materials (WLMs). The results indicated that, on a dry weight basis, CRF material from a range of green biomass was enriched in lipids and proteins, and in a range of micronutrients compared with the WLM. Vitamins E, pro-vitamin A, and lutein were all greater in CRF preparations. Of the minerals, iron was most notably concentrated in CRF. Spinach CRFs possessed the highest α-tocopherol [62 mg 100 g^-1, dry weight (DW)], β-carotene (336 mg 100 g^-1 DW) and lutein (341 mg 100 g^-1 DW) contents, whilst grass CRFs had the highest concentration of alpha-linolenic acid (ALA) (69.5 mg g^-1). The higher concentrations of α-tocopherol, β-carotene, lutein, ALA and trace minerals (Fe and Mn) in CRFs suggested their potential use as concentrated ingredients in food formulations deficient in these nutrients.

Nonalcoholic fatty liver disease impairs the cytochrome P-450-dependent metabolism of α-tocopherol (vitamin E)

This study aims to investigate in in vivo and in vitro models of nonalcoholic fatty liver disease (NAFLD) the enzymatic metabolism of α-tocopherol (vitamin E) and its relationship to vitamin E-responsive genes with key role in the lipid metabolism and detoxification of the liver. The experimental models included mice fed a high-fat diet combined or not with fructose (HFD+F) and HepG2 human hepatocarcinoma cells treated with the lipogenic agents palmitate, oleate or fructose. CYP4F2 protein, a cytochrome P-450 isoform with proposed α-tocopherol ω-hydroxylase activity, decreased in HFD and even more in HFD+F mice liver; this finding was associated with increased hepatic levels of α-tocopherol and decreased formation of the corresponding long-chain metabolites α-13-hydroxy and α-13-carboxy chromanols. A decreased expression was also observed for PPAR-γ and SREBP-1 proteins, two vitamin E-responsive genes with key role in lipid metabolism and CYP4F2 gene regulation. A transient activation of CYP4F2 gene followed by a repression response was observed in HepG2 cells during the exposure to increasing levels of the lipogenic and cytotoxic agent palmitic acid; such gene repression effect was further exacerbated by the co-treatment with oleic acid and α-tocopherol and was also observed for PPAR-γ and the SREBP isoforms 1 and 2. Such gene response was associated with increased uptake and ω-hydroxylation of α-tocopherol, which suggests a minor role of CYP4F2 in the enzymatic metabolism of vitamin E in HepG2 cells. In conclusion, the liver metabolism and gene response of α-tocopherol are impaired in experimental NAFLD.

Antioxidant defense system in familial hypercholesterolemia and the effects of lipoprotein apheresis

Oxidative stress is thought to play an important role in the pathogenesis of disorders associated with atherosclerosis. Alpha-tocopherol is considered to be an effective lipophilic antioxidant, which protects lipid membranes against peroxidation and thus prevents cell damage by reaction with free radicals. However, measurement of alpha-tocopherol concentration in serum does not reflect the content of α-tocopherol in membranes whereas erythrocyte alpha-tocopherol may be good indicator of antioxidative status. Therefore a simple isocratic reversed phase HPLC method has been developed and validated for the determination of alpha-tocopherol in human erythrocytes in a clinical setting. The content of alpha-tocopherol in human erythrocyte membrane and lipoperoxidation were studied in patients with severe hypercholesterolemia treated by lipoprotein apheresis. The group of hypercholesterolemic patients (n = 14) treated by lipoprotein apheresis was compared to healthy adult normolipidemic controls. After lipoprotein apheresis, the content of in membrane alpha-tocopherol did not change significantly despite decreased tocopherol in serum and lipoprotein fractions. We observed significantly decreased lipoperoxidation as revealed by serum TBARS, representing end products of lipid peroxidation, which increased from third day afterwards and remained significantly higher in comparison to controls until the next LDL-apheresis. We conclude that aggressive lipid lowering procedure with lipoprotein apheresis was associated with favorable transient decrease of lipoperoxidation. Simultaneously the cell membrane bound antioxidative defense mechanisms as reflected by the content of alpha-tocopherol in human erythrocyte membrane where not depressed in spite of its decreased plasma lipid carrier. Another variables involved remain to be investigated.

Plasma alpha-tochopherol determined by HPLC in dogs at different stages of chronic kidney disease: a retrospective study

The aim of the present study was to investigate retrospectively the plasma concentration of alpha-tocopherol in dogs with naturally acquired chronic kidney disease (CKD), at different stages of severity. Forty dogs (CKD group) with different stages of CKD (IRIS 1 n=12, IRIS 2 n=8, IRIS 3 n=11, IRIS 4 n=9) and 20 clinically healthy dogs were considered. Plasma alpha-tocopherol was assessed in both groups through high performance liquid chromatography (HPLC). Dogs of CKD group showed significantly lower (p=0.0002) levels of plasma alpha-tocopherol compared with clinically healthy dogs. A significant difference (p<0.04) in the number of patients with plasma alpha-tocopherol > or ≤ 21.5 ppm was found in CKD patients at different stages of severity. No significant correlation between plasma levels of alpha-tocopherol and plasma creatinine was found. In the present study, dogs affected by spontaneous CKD showed significantly lower plasma concentrations of alpha-tocopherol compared with clinically healthy dogs. Plasma alpha-tocopherol deficiency seems to be more severe in IRIS stage 1 and 4, compared with IRIS stage 2 and 3. The finding of marked alpha-tocopherol deficiency in patients in IRIS stage 1 should encourage further studies on the early use of prescription renal diet and antioxidant in this group of patients.

Alpha-tocopherol-dependent salt tolerance is more related with auxin synthesis rather than enhancement antioxidant defense in soybean roots

In this paper, we describe the alleviated effects of alpha-tocopherol (α-T) on oxidative damage and its possible role as a signal transmitter in plants during salt stress. The results show that exogenously applied α-T under salt stress increased root length and weight, but reduced hydrogen peroxide (H2O2), superoxide anion radical (O2.-) and malondialdehyde (MDA) content in soybean roots. The proline content was reduced by α-T treatment. Interestingly, endogenous auxin (IAA) level was significantly increased after α-T application as compared to salt stress alone. Moreover, α-T reduced significantly superoxide dismutase (SOD) enzyme and isoenzyme activity but upregulated peroxidase (POX) 2, 3 and glutathione-s-transferase (GST) 1, 3 isoenzyme expression. However, ascorbate peroxidase (APX) enzyme activity was not affected at all. Consequently, the results show that α-T serves as a signal molecule under salinity from leaves to roots by increasing remarkably endogenous IAA levels and increasing partially antioxidant activity in roots.

Lipid quantitation and metabolomics data from vitamin E-deficient and -sufficient zebrafish embryos from 0 to 120 hours-post-fertilization

The data herein is in support of our research article by McDougall et al. (2017) [1], in which we used our zebrafish model of embryonic vitamin E (VitE) deficiency to study the consequences of VitE deficiency during development. Adult 5D wild-type zebrafish (Danio rerio), fed defined diets without (E–) or with VitE (E+, 500 mg RRR-α-tocopheryl acetate/kg diet), were spawned to obtain E– and E+ embryos that we evaluated using metabolomics and specific lipid analyses (each measure at 24, 48, 72, 120 hours-post-fertilization, hpf), neurobehavioral development (locomotor responses at 96 hpf), and rescue strategies. Rescues were attempted using micro-injection into the yolksac using VitE (as a phospholipid emulsion containing d₆-α-tocopherol at 0 hpf) or D-glucose (in saline at 24 hpf).

Effect of maternal supplementation with vitamin E on the concentration of α-tocopherol in colostrum

OBJECTIVE

To evaluate the effect of maternal supplementation with vitamin E on the concentration of α-tocopherol in colostrum and its supply to the newborn.

METHOD

This randomized clinical trial enrolled 99 healthy adult pregnant women; of these, 39 were assigned to the control group and 60 to the supplemented group. After an overnight fast, 5mL of blood and 2mL of colostrum were collected. After the first sampling (0h milk), the supplemented group received 400IU of supplementary vitamin E. Another 2mL milk aliquot was collected in both groups 24h after supplementation (24h milk). The samples were analyzed by high-performance liquid chromatography. The α-tocopherol content provided by colostrum was calculated by considering a daily intake of 396mL of milk and comparing the resulting value to the recommended daily intake for infants aged 0-6 months (4mg/day).

RESULTS

The initial mean concentration of α-tocopherol in colostrum was 1509.3±793.7μg/dL in the control group and 1452.9±808.6μg/dL in the supplemented group. After 24h, the mean α-tocopherol concentration was 1650.6±968.7μg/dL in the control group (p>0.05) and 2346.9±1203.2μg/dL in the supplemented group (p<0.001), increasing the vitamin E supply to the newborn to 9.3mg/day. Initially, 18 women in the supplemented group provided colostrum α-tocopherol contents below 4mg/day; after supplementation only six continued to provide less than the recommended amount.

CONCLUSION

Maternal vitamin E supplementation increases the supply of the vitamin to the infant by providing more than twice the Recommended Daily Intake.

Ginkgo biloba leaf extract and alpha-tocopherol attenuate haloperidol-induced orofacial dyskinesia in rats: Possible implication of antiapoptotic mechanisms by preventing Bcl-2 decrease and Bax elevation

BACKGROUND

Tardive dyskinesia (TD) is a serious side effect of long-term administration of typical neuroleptics, such as haloperidol. The pathophysiology of TD remains unclear, but the experimental evidence suggests that free radical-induced neuronal apoptosis in the basal ganglia may play an important role.

PURPOSE

This study was to investigate changes in Bax and Bcl-2 expression levels in TD-associated brain regions and the effects of the antioxidant EGb761 on Bax and Bcl-2 levels in an animal model of TD.

METHODS

Thirty-two rats were randomly divided into four study groups: saline control (saline), haloperidol-alone (haloperidol), EGb761-haloperidol (EGb), and alpha-tocopherol-haloperidol (vitamin E). Rats were treated with daily intraperitoneal haloperidol injections (2 mg/kg/day) for 5 weeks. EGb761 (50 mg/kg/day) and alpha-tocopherol (20 mg/kg/day) were then administered for another 5 weeks during the withdrawal period. Behavioral assessments were performed, and Bax and Bcl-2 protein expression levels were immunohistochemically analyzed in four brain regions, including the prefrontal cortex, striatum, substantia nigra, and globus pallidum.

RESULTS

We found that increased vacuous chewing movements (VCMs) were associated with increased proapoptotic Bax protein expression, decreased antiapoptotic Bcl-2 protein expression, and an increased Bax/Bcl-2 ratio. EGb761 and alpha-tocopherol treatment reversed the increase in VCMs, decreased Bax expression, increased Bcl-2 expression, and decreased the Bax/Bcl-2 ratio.

CONCLUSIONS

These results demonstrate that long-term haloperidol administration may affect Bcl-2 protein family expression and promote neuronal apoptosis in the basal ganglia. In combination with their antioxidant capacity, EGb761 and alpha-tocopherol's antiapoptotic effects through Bcl-2 might account for the symptom improvement observed in haloperidol-induced TD rats.

The long chain α-tocopherol metabolite α-13'-COOH and γ-tocotrienol induce P-glycoprotein expression and activity by activation of the pregnane X receptor in the intestinal cell line LS 180

SCOPE

Members of the vitamin E family or their metabolites may induce the xenobiotic transporter P-glycoprotein (P-gp), which can limit the bioavailability of drugs and phytochemicals. This study aimed to investigate if α- and γ-tocopherol, α- and γ-tocotrienol, the long chain metabolite α-tocopherol-13'-COOH, the short chain metabolites α- and γ-carboxyethylhydroxychromanol and plastochromanol-8 activate the pregnane X receptor (PXR) and thereby modulate P-gp expression and/or activity.

METHODS AND RESULTS

P-gp protein expression and activity were studied in LS 180 cells incubated with the respective test compound for 48 h. Furthermore, we determined if the compounds activate PXR in LS 180 cells, as PXR regulates P-gp expression. Neither P-gp protein expression and activity, nor PXR activity were influenced by α-tocopherol, γ-tocopherol and plastochromanol-8. α-Tocotrienol activated PXR in the reporter gene assay but did not induce protein expression or activity of P-gp. γ-Tocotrienol and α-13'-COOH activated PXR and induced protein expression and transporter activity of P-gp.

CONCLUSION

Because the induction of P-gp in the intestine may limit the systemic bioavailability of its substrates, the concurrent intake of drugs and γ-tocotrienol and, if ever applicable, α-13'-COOH should be avoided.

Insufficient evidence for vitamin E in Alzheimer's disease

Vitamin E has recently been suggested to slow down the progression of Alzheimer's disease. Current evidence is based on three studies in patients with Alzheimer's disease and one study in patients with mild cognitive impairment which all together included only 1756 patients. Importantly, two of these studies were negative, and the two other studies had severe methodological weaknesses that preclude more definite interpretation. Based on the notion from patients suffering from cerebrovascular diseases that vitamin E may induce serious side effects (i.e., hemorhagic stroke), vitamin E cannot be recommended for use in Alzheimer's patients.

Vitamin E homologues α- and γ-tocopherol are not associated with bone turnover markers or bone mineral density in peri-menopausal and post-menopausal women

In a large cohort of older women, we investigated the relationships that different forms of vitamin E may have with bone turnover markers and bone mineral density (BMD). We found a suggestive positive association between serum alpha-tocopherol and BMD at the femoral neck, but no other clinically relevant observations.

INTRODUCTION

Vitamin E has anti-oxidant and anti-inflammatory properties hypothesized to benefit bone, but limited studies exist regarding its homologues. We examined circulating and dietary α- and γ-tocopherols with bone turnover markers (BTMs) and bone mineral density (BMD), and the role of inflammation in this relationship.

METHODS

We performed two cross-sectional analyses from two visits (V2, 1997-1999, n = 3883; V3, 2007-2011, n = 2130) of the Aberdeen Prospective Osteoporosis Screening Study. Dietary and supplement intakes by food frequency questionnaire were assessed at both visits. V2 BTMs (urinary free pyridinoline and deoxypyridinoline, serum N-terminal propeptide of type 1 collagen) and V3 serum α- and γ-tocopherols, inflammatory markers (interleukin-6 [IL-6], serum amyloid A [SAA], high-sensitivity C-reactive protein [hs-CRP], E-selectin) and dual X-ray absorptiometry BMD at the femoral neck and lumbar spine were collected. Food sources of tocopherol homologues and diet-serum correlations were determined. The relationships between dietary tocopherols and BTMs (V2), and dietary and serum tocopherols with BMD (V3) were examined by multivariable regression (adjusting for age, cholesterol, inflammatory markers, carotenoids, body mass index, physical activity level, alcohol intake, smoking status and national deprivation category).

RESULTS

Serum γ-tocopherol was associated with increasing concentrations of hs-CRP, SAA and E-selectin (P-trend all <0.0001), while α-tocopherol was associated with decreasing concentrations of IL-6 and hs-CRP (P-trend all <0.001). Controlling for covariates, serum α-tocopherol was positively associated with BMD at the femoral neck (β = 0.002, P = 0.04) among those not reporting vitamin E supplementation.

CONCLUSION

We did not find biologically meaningful results between dietary and tocopherol homologues with BTMs or BMD.

The effects of the antioxidant α-tocopherol succinate on cisplatin-induced ototoxicity in HEI-OC1 auditory cells

CONCLUSION

D-α-tocopherol succinate significantly reduced a cisplatin-induced hair cell loss in HEI-OC1 cell lines. These effects were mediated by its scavenging activity against reactive oxygen species (ROS) and inhibition of apoptosis.

OBJECTIVES

Alpha-tocopherol is a class of methylated phenols, known as fat-soluble antioxidants, and is a different form of vitamin E, which reduces free radicals and acts as an antioxidant. We hypothesized that the antioxidative effect of α-tocopherol could protect against cisplastin-induced cytotoxicity, and thus evaluated its effects on cisplatin-induced ototoxicity in HEI-OC1 auditory cells.

METHODS

HEI-OC1 cells were pretreated with D-α-tocopherol succinate at a concentration of 10 µM for 24 h, and then exposed to 15 µM cisplatin for 48 h. The cellular viability was measured by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The intracellular ROS level was measured by using a fluorescent dye, 2',7'-dichlorofluorescein diacetate (DCFH-DA). Both Annexin V-FITC and propidium iodide (PI) staining were performed to analyze the pattern of apoptosis. The enzymatic activity of caspase-3 was assayed with caspase3/CPP32 fluorometric assay kit. Also, it was assessed by immunoblotting technique of poly-ADP-ribose polymerase (PARP).

RESULTS

Pretreatment with 10 µM D-α-tocopherol succinate protected HEI-OC1 auditory cells against cisplatin-induced cytotoxicity. D-α-tocopherol succinate significantly reduced the cisplatin-induced increase in ROS. D-α-tocopherol succinate treatment induced a 15% reduction of ROS and 50% decrease in necrosis and late apoptosis as compared to cisplatin treatment. D-α-tocopherol succinate also decreased the activation of caspase-3 and reduced levels of cleaved poly-ADP-ribose polymerase (PARP).

Effect of long-term vitamin E and selenium supplementation on urine F2-isoprostanes, a biomarker of oxidative stress

BACKGROUND

Cigarette smoking generates reactive oxidant species and contributes to systemic oxidative stress, which plays a role in the pathophysiology of chronic diseases. Nutrients with antioxidant properties, including vitamin E and selenium, are proposed to reduce systemic oxidative burden and thus to mitigate the negative health effects of reactive oxidant species.

OBJECTIVE

Our objective was to determine whether long-term supplementation with vitamin E and/or selenium reduces oxidative stress in smokers, as measured by urine 8-iso-prostaglandin F2-alpha (8-iso-PGF2α).

DESIGN

We measured urine 8-iso-PGF2α with competitive enzyme linked immunoassay (ELISA) in 312 male current smokers after 36 months of intervention in a randomized placebo-controlled trial of vitamin E (400IU/d all rac-α-tocopheryl acetate) and/or selenium (200µg/d L-selenomethionine). We used linear regression to estimate the effect of intervention on urine 8-iso-PGF2α, with adjustments for age and race.

RESULTS

Compared to placebo, vitamin E alone lowered urine 8-iso-PGF2α by 21% (p=0.02); there was no effect of combined vitamin E and selenium (intervention arm lower by 9%; p=0.37) or selenium alone (intervention arm higher by 8%; p=0.52).

CONCLUSIONS

Long-term vitamin E supplementation decreases urine 8-iso-PGF2α among male cigarette smokers, but we observed little to no evidence for an effect of selenium supplementation, alone or combined with vitamin E.

Alpha-tocopherol ameliorates experimental autoimmune encephalomyelitis through the regulation of Th1 cells

OBJECTIVES

Multiple sclerosis (MS) is a serious neurological autoimmune disease, it commonly affects young adults. Vitamin E (Vit E) is an important component of human diet with antioxidant activity, which protects the body's biological systems. In order to assess the effect of Vit E treatment on this autoimmune disease, we established experimental autoimmune encephalomyelitis (EAE), the animal model of MS, and treated EAE with α-tocopherol (AT) which is the main content of Vit E.

MATERIALS AND METHODS

Twenty C57BL/6 adult female mice were used and divided into two groups randomly. EAE was induced with myelin oligodendrocyte glycoprotein (MOG), and one group was treated with AT, at a dose of 100 mg/kg on the 3(th) day post-immunization with MOG, the other group was treated with 1% alcohol. Mice were euthanized on day 14, post-immunization, spleens were removed for assessing splenocytes proliferation and cytokine profile, and spinal cords were dissected to assess the infiltration of inflammatory cells in spinal cord.

RESULTS

AT was able to attenuate the severity of EAE and delay the disease progression. H&E staining and fast blue staining indicated that AT reduced the inflammation and the demyelination reaction in the spinal cord. Treatment with AT significantly decreased the proliferation of splenocytes. AT also inhibited the production of IFN-γ (Th1 cytokine), though the other cytokines were only affected slightly.

CONCLUSION

According to the results, AT ameliorated EAE, through suppressing the proliferation of T cells and the Th1 response. AT may be used as a potential treatment for MS.

Comparative evaluation of superoxide dismutase, alpha-tocopherol, and 10% sodium ascorbate on reversal of shear bond strength of bleached enamel: An in vitro study

OBJECTIVE

The aim of this study was to investigate the neutralizer effect of antioxidant agents on the bond strength of bleached enamel.

MATERIALS AND METHODS

Sixty enamel slabs were prepared from 60 freshly extracted maxillary central incisors and were divided into six groups. The negative control group received no bleaching treatment and the other groups were bleached with 35% carbamide peroxide (Opalescence Quick; Ultradent, South Jordan, USA). In Group II, composite was built immediately after bleaching and cured without any antioxidants. In Group III, bleached specimens received composite build ups delayed by 1 week. In Groups IV, V, and VI bleached specimens received applications of superoxide dismutase (SOD), sodium ascorbate (SA), and tocopherol solutions, respectively, for 10 min. Following composite bonding, the micro shear bond strength (μSBS) was measured at a speed of 1 mm/min in universal testing machine.

STATISTICAL ANALYSIS USED

The μSBS values of all the groups were analyzed using the analysis of variance followed by Tukey honestly significant difference post-hoc test.

RESULTS

Bonding of composites to unbleached group (Group I) exhibited the highest mean SBS values and among the antioxidant-treated groups, the highest SBS values were seen with SOD (Group IV) treated samples (23.0040 ± 4.30565 MPa).

CONCLUSIONS

Application of SA, alpha-tocopherol, and SOD can effectively reverse the bond strength with bleached enamel. SOD gave a comparatively more promising reversal of bond strength than SA and alpha-tocopherol, and deserves further studies.

Bioavailability of Orally Delivered Alpha-Tocopherol by Poly(Lactic-Co-Glycolic) Acid (PLGA) Nanoparticles and Chitosan Covered PLGA Nanoparticles in F344 Rats

It is hypothesized that the bioavailability of αT (alpha-tocopherol), an antioxidant, can be improved when delivered by poly(lactic-co-glycolic) acid (PLGA) nanoparticles (NPs) and chitosan covered PLGA nanoparticles (PLGA-Chi NPs), and that the mucoadhesive properties of chitosan may enhance absorption of αT. PLGA and PLGA-Chi NPs were characterized by measuring entrapment efficiency, size, polydispersity, and zeta potential. Nanoparticle physical stability, chemical stability of entrapped αT, and release kinetics were also measured. Pharmacokinetic studies were conducted by administering PLGA (αT) NPs, PLGA-Chi (αT) NPs, and free αT via oral gavage in rats. The size and zeta potential of the two particle systems were 97.87 ± 2.63 nm and -36.2 ± 1.31 mV for PLGA(αT) NPs, and 134 ± 2.05 nm and 38.0 ± 2.90 mV for PLGA-Chi (αT) nanoparticles in DI water. The particle systems showed to be stable during various in vitro assays. Bioavailability of nanodelivered αT was improved compared to the free αT, by 170% and 121% for PLGA and PLGA-Chi NPs, respectively. It was concluded that while chitosan did not further improved bioavailability of αT, PLGA NPs protected the entrapped drug from the GI environment degradation and proved to be an effective delivery system for αT.