Vitamin E in human health and disease

From A to E: Uniting vitamins against stroke risk-A systematic review and network meta-analysis

BACKGROUND AND AIM

Stroke represents a significant public health challenge, necessitating the exploration of preventive measures. This network meta-analysis aimed to assess the efficacy of different vitamin treatments compared to a placebo in preventing stroke.

METHODS

A systematic electronic search in databases including PubMed, EmBASE, Web of Science, clinicaltrials.gov, and Google Scholar until 31 May 2023 was conducted, to identify published studies investigating the association between vitamin intake and the risk of stroke. Pooled risk ratio (RR) with 95% confidence intervals (CIs) was calculated using a frequentist network meta-analysis. Furthermore, we ranked vitamins based on p-scores, facilitating a comparative assessment of their effectiveness in preventing stroke.

RESULTS

A total of 56 studies, including 17 randomized controlled trials (RCTs) and 39 cohort studies were analyzed. Direct estimates obtained from network meta-analysis, we found that vitamin A (RR: .81 [.72-.91]), vitamin B-complex (RR: .85 [.74-.97]), vitamin B6 (RR: 79 [.68-.92]), folate (RR: .86 [.75-.97]), vitamin C (RR: .77 [.70-.85]) and vitamin D (RR: .73 [.64-.83]) were significantly associated with a decreased stroke risk. However, no significant association was observed for vitamin B2, vitamin B12, and vitamin E. Subsequent to network meta-analysis, vitamins were ranked in decreasing order of their efficacy in stroke prevention based on p-score, with vitamin D (p-score = .91), vitamin C (p-score = .79), vitamin B6 (p-score = .70), vitamin A (p-score = .65), vitamin B-complex (p-score = .53), folate (p-score = .49), vitamin B2 (p-score = .39), vitamin E (p-score = .28), vitamin B12 (.13) and placebo (.10).

CONCLUSION

Our study has established noteworthy connections between vitamin A, vitamin B-complex, vitamin B6, folate, vitamin C, and vitamin D in the realm of stroke prevention. These findings add substantial weight to the accumulating evidence supporting the potential advantages of vitamin interventions in mitigating the risk of stroke. However, to solidify and validate these observations, additional research is imperative. Well-designed clinical trials or cohort studies are needed to further explore these associations and formulate clear guidelines for incorporating vitamin supplementation into effective stroke prevention strategies.

A Summary of Two Decades of QTL and Candidate Genes That Control Seed Tocopherol Contents in Maize (Zea mays L.)

Tocopherols are secondary metabolites synthesized through the shikimate biosynthetic pathway in the plastids of most plants. It is well known that α-Tocopherol (vitamin E) has many health benefits for humans and animals; therefore, it is highly used in human and animal diets. Tocopherols vary considerably in most crop (and plant) species and within cultivars of the same species depending on environmental and growth conditions; tocopherol content is a polygenic, complex traits, and its inheritance is poorly understood. The objective of this review paper was to summarize all identified quantitative trait loci (QTL) that control seed tocopherols and related contents identified in maize (Zea mays) during the past two decades (2002-2022). Candidate genes identified within these QTL regions are also discussed. The QTL described here, and candidate genes identified within these genomic regions could be used in breeding programs to develop maize cultivars with high, beneficial levels of seed tocopherol contents.

Greenness Assessment and Validation of HPLC Method for Simultaneous Determination of Resveratrol and Vitamin E in Dietary Supplements

BACKGROUND

There is an increasing interest in the use of a combination of trans-resveratrol and vitamin E in dietary supplements. Determination of the content of both components is essential for confirmation of the quality of the product.

OBJECTIVE

To establish the applicability and ensure the greenness of the previously developed high-throughput HPLC/UV method for the simultaneous determination of trans-resveratrol and alpha-tocopherol acetate (vitamin E) in dietary supplements.

METHOD

Separation was performed on RP C8 Select B chromatographic column, using acetonitrile and water in the mobile phase, with gradient elution. Full method validation was performed in accordance with ICH Q2(R1). The greenness of the method was assessed using the analytical eco-scale (AES) methodology and the analytical greenness metric (AGREE).

RESULTS

The method is selective, linear, precise, and accurate over defined concentration ranges (185-369 µg/mL of trans-resveratrol and 37-75 µg/mL of alpha-tocopherol acetate), and it has a suitable sensitivity (limits of detection and quantification are 7.7 and 23.3 µg/mL for resveratrol and 2.6 and 7.8 µg/mL for tocopherol acetate, respectively). The obtained analytical eco-scale score of 77 and the pale green AGREE pictogram with an overall score of 0.61 confirm the method's greenness.

CONCLUSIONS

The sensitivity and selectivity of the method, its short analysis time (7 min), the low negative environmental impact, and the simple sample preparation make the method readily applicable to inline quality control procedures.

HIGHLIGHTS

A method for simultaneously analyzing vitamin E and resveratrol in dietary supplements is presented. The method is rapid, includes a simple sample preparation procedure, and has a low environmental impact.

Pilot Study of Heat-Stabilized Rice Bran Acceptability in Households of Rural Southwest Guatemala and Estimates of Fiber, Protein, and Micro-Nutrient Intakes among Mothers and Children

Nutrient-dense, acceptable foods are needed in low-resource settings. Rice bran, a global staple byproduct of white rice processing, is rich in amino acids, fibers, and vitamins, when compared to other cereal brans. This pilot study examines the nutritional contribution of rice bran to the daily diets of mother-child pairs in rural southwest Guatemala. Thirty households were screened. Mothers (≥18 years) and children (6 to 24 months) completed 24 h dietary recalls at baseline and after 12 weeks (endline) for diet intake and diversity analyses. During biweekly visits for 12 weeks, households with <5 members received 14 packets containing 60 g of heat-stabilized rice bran, and those with ≥5 members received 28 packets. The macro- and micro-nutrient contributions of rice bran and whole, cooked black beans were included in dietary simulation models with average intakes established between the recalls and for comparison with dietary reference intakes (DRIs). A baseline child food frequency questionnaire was administered. The 27 mothers and 23 children with complete recalls were included in analyses. Daily maternal consumption of 10 g/d of rice bran plus 100 g/d of black beans resulted in all achieving at least 50% of the fiber, protein, magnesium, niacin, potassium, and thiamin DRIs. Daily child consumption of 3 g/d of rice bran plus 10 g/d of black beans resulted in all achieving at least 50% of the magnesium, niacin, phosphorous, and thiamine DRIs. For 15/17 food categories, male children had a higher intake frequency, notably for animal-source foods and coffee. Dietary rice bran coupled with black beans could improve nutritional adequacy, especially for fiber and key micro-nutrients, with broader implications for addressing maternal and child malnutrition in low-resource settings.

Protective role of Pleurotus florida against streptozotocin-induced hyperglycemia in rats: A preclinical study

Pleurotus florida (Mont.) Singer is a mushroom species known to be an antioxidant, immunomodulatory, and diuretic agent, reducing blood pressure and cholesterol. The aim of this study was to evaluate the in vivo potency of P. florida's anti-diabetic properties in rats affected by hyperglycemia induced by Streptozotocin (STZ) at 55 mg/kg (i.p.), characterized by oxidative stress impairment, and changes in insulin levels and lipid profile. After inducing hyperglycemia in the rats, they were treated with P. florida acetone and methanol extracts, orally administered for 28 days at doses of 200 mg/kg and 400 mg/kg body weight. The hyperglycemic control (DC) group showed significant increases (P < 0.05) in mean blood sugar, total cholesterol, triglycerides, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, blood urea nitrogen, lipid hydroperoxides, and malondialdehyde, compared to the normal control (NC) group The high-density lipoprotein cholesterol, serum insulin, superoxide dismutase, catalase, glutathione disulfide, glutathione peroxidase, reduced glutathione, guaiacol peroxidase, and vitamin E and C levels showed a significant decrease (P < 0.05) in DC group, compared to the NC group. Blood glucose levels, lipid profiles, and insulin levels improved significantly after 28 days of treatment, in the group treated with glibenclamide (an oral hypoglycemic drug, used as positive control), and in the groups treated with P. florida extracts. In DC group, the treatment with P. florida was found to prevent diabetes, according to histopathological studies of the kidneys, pancreas, and liver of rats. In conclusion, this study has shown that the treatment with P. florida decreased oxidative stress and glucose levels in the blood, as well as restoring changes in lipid profiles.

Clotting Propensity of Surface-Treated Membranes in a Hemodialysis Set-up That Avoids Systemic Anticoagulation

The development of biocompatible membranes, aiming to limit the inflammatory response, oxidative stress, and coagulability during hemodialysis, has been an important step in reducing dialysis-related adverse outcomes. This includes a reduction in the risk of clotting of the extracorporeal circuit, thus enabling hemodialysis with a reduced dose or even without systemic anticoagulant drugs in patients with an increased bleeding risk. In this article, we summarize the in vitro research and clinical evidence on the antithrombotic properties of vitamin E- and heparin-coated membranes.

Vitamin E Supplementation and Cardiovascular Health: A Comprehensive Review

This article conducts a thorough investigation into the potential role of vitamin E in preventing cardiovascular diseases (CVDs) in the context of shifting mortality patterns from infectious diseases to the continued prominence of CVDs in modern medicine. The primary focus is on vitamin E's antioxidant properties and its specific ability to counter lipid peroxidation, a pivotal process in the early stages of atherosclerosis, a precursor to CVDs. The research spans a wide range of methodologies, including in vitro, in vivo, clinical, and experimental studies, examining how vitamin E affects critical aspects of cardiovascular health, such as signaling pathways, gene expression, inflammation, and cholesterol metabolism. It also explores vitamin E's influence on complex processes like smooth muscle cell development, oxidative stress reduction, foam cell formation, and the stability of atherosclerotic plaques. In the context of clinical studies, the article presents findings that both support and yield inconclusive results regarding the impact of vitamin E supplementation on CVDs. It acknowledges the intricate interplay of factors such as patient selection, pathophysiological conditions, and genetic variations, all of which can significantly influence the efficacy of vitamin E. The article underscores the need for ongoing research, with a specific focus on understanding the regulatory metabolites of vitamin E and their roles in modulating cellular processes relevant to CVDs. It highlights the potential for innovative therapeutic approaches based on a deeper comprehension of vitamin E's multifaceted effects. However, it also candidly addresses the challenges of translating clinical trial findings into practical applications and emphasizes the importance of considering diverse variables to optimize therapeutic outcomes. In summary, this meticulously conducted study provides a comprehensive examination of vitamin E's potential as a preventive agent against CVDs, recognizing the complexity of the subject and the need for continued research to unlock its full potential in cardiovascular health.

Potential Role of Natural Antioxidants in Countering Reperfusion Injury in Acute Myocardial Infarction and Ischemic Stroke

Stroke and acute myocardial infarction are leading causes of mortality worldwide. The latter accounts for approximately 9 million deaths annually. In turn, ischemic stroke is a significant contributor to adult physical disability globally. While reperfusion is crucial for tissue recovery, it can paradoxically exacerbate damage through oxidative stress (OS), inflammation, and cell death. Therefore, it is imperative to explore diverse approaches aimed at minimizing ischemia/reperfusion injury to enhance clinical outcomes. OS primarily arises from an excessive generation of reactive oxygen species (ROS) and/or decreased endogenous antioxidant potential. Natural antioxidant compounds can counteract the injury mechanisms linked to ROS. While promising preclinical results, based on monotherapies, account for protective effects against tissue injury by ROS, translating these models into human applications has yielded controversial evidence. However, since the wide spectrum of antioxidants having diverse chemical characteristics offers varied biological actions on cell signaling pathways, multitherapy has emerged as a valuable therapeutic resource. Moreover, the combination of antioxidants in multitherapy holds significant potential for synergistic effects. This study was designed with the aim of providing an updated overview of natural antioxidants suitable for preventing myocardial and cerebral ischemia/reperfusion injuries.

Association of gamma-tocopherol serum concentrations and blood pressure among adults in the United States: a cross-sectional study

Background

hypertension is one of the major preventable risk factors for numerous diseases. The role of vitamin E in blood pressure (BP) has been controversial. We aimed to investigate the relationship between gamma-tocopherol serum concentration (GTSC) and BP.

Methods

Data from 15,687 US adults from the National Health and Nutrition Examination Survey (NHANES) were analyzed. The correlations of GTSC with systolic BP (SBP), diastolic BP (DBP), and prevalence of hypertension were investigated by multivariate logistic regression models, generalized summation models, and fitted smoothing curves. Subgroup analyses were performed to investigate possible effect modifiers between them.

Results

With each natural log increase in GTSC, SBP, and DBP increased by 1.28 mmHg (β 1.28, 95% CI 0.71-1.84) and 1.15 mmHg (β 1.15, 95% CI 0.72-1.57), respectively, both P for trend < 0.001; the prevalence of hypertension increased by 12% (OR 1.12, 95% CI 1.03-1.22), P for trend 0.008. In subgroup analysis, in drinkers, with each natural log increase in GTSC, SBP, and DBP increased by 1.77 mmHg (β 1.77,95% CI 1.13-2.41) and 1.37 mmHg (β 1.37,95% CI 0.9-1.85), respectively, whereas they were not correlated in non-drinkers.

Conclusion

GTSC was linearly and positively associated with SBP, DBP, and the prevalence of hypertension, and alcohol consumption may modify the relationship of GTSC with SBP and DBP.

Nutritional Factors: Benefits in Glaucoma and Ophthalmologic Pathologies

Glaucoma is a chronic optic neuropathy that can lead to irreversible functional and morphological damage if left untreated. The gold standard therapeutic approaches in managing patients with glaucoma and limiting progression include local drops, laser, and/or surgery, which are all geared at reducing intraocular pressure (IOP). Nutrients, antioxidants, vitamins, organic compounds, and micronutrients have been gaining increasing interest in the past decade as integrative IOP-independent strategies to delay or halt glaucomatous retinal ganglion cell degeneration. In our minireview, we examine the various nutrients and compounds proposed in the current literature for the management of ophthalmology diseases, especially for glaucoma. With respect to each substance considered, this minireview reports the molecular and biological characteristics, neuroprotective activities, antioxidant properties, beneficial mechanisms, and clinical studies published in the past decade in the field of general medicine. This study highlights the potential benefits of these substances in glaucoma and other ophthalmologic pathologies. Nutritional supplementation can thus be useful as integrative IOP-independent strategies in the management of glaucoma and in other ophthalmologic pathologies. Large multicenter clinical trials based on functional and morphologic data collected over long follow-up periods in patients with IOP-independent treatments can pave the way for alternative and/or coadjutant therapeutic options in the management of glaucoma and other ocular pathologies.

Dietary Supplement Intake and Fecundability in a Singapore Preconception Cohort Study

Subfertility is a global problem affecting millions worldwide, with declining total fertility rates. Preconception dietary supplementation may improve fecundability, but the magnitude of impact remains unclear. This prospective cohort study aimed to examine the association of preconception micronutrient supplements with fecundability, measured by time to pregnancy (TTP). The study was conducted at KK Women's and Children's Hospital, Singapore, between February 2015 and October 2017, on 908 women aged 18-45 years old, who were trying to conceive and were enrolled in the Singapore PREconception Study of long-Term maternal and child Outcomes (S-PRESTO). Baseline sociodemographic characteristics and supplement intake were collected through face-to-face interviews. The fecundability ratio (FR) was estimated using discrete-time proportional hazard modelling. Adjusting for potentially confounding variables, folic acid (FA) (FR 1.26, 95% confidence interval 1.03-1.56) and iodine (1.28, 1.00-1.65) supplement users had higher fecundability compared to non-users. Conversely, evening primrose oil supplement users had lower fecundability (0.56, 0.31-0.99) than non-users. In this study, preconception FA and iodine supplementation were associated with shortened TTP, while evening primrose oil use was associated with longer TTP. Nonetheless, the association between supplement use and the magnitude of fecundability changes will need to be further confirmed with well-designed randomised controlled trials.

The effect of Vitamins C and E on clinical outcomes of patients with severe traumatic brain injury: A propensity score matching study

Background

The aim of this study was to assess the effect of Vitamins C and E on mortality, intensive care unit (ICU) length of stay, and Glasgow Outcome Scale-Extended (GOS-E) score of traumatic brain injury (TBI) patients.

Methods

Using data from records of patients in a retrospective cohort study, we included 1321 TBI patients, 269 treated and 1052 untreated, aged over 18 years with information on exposure (i.e., Vitamins C and E) and confounders. Age, Glasgow Coma Scale, pupil status, Rotterdam classification, blood sugar, blood pressure, international normalized ratio, and comorbidity of patients were considered as the confounding factors. Endpoints were GOS-E on follow-up, mortality, and ICU length of stay. Propensity score matching was performed to adjust the confounders.

Results

Based on the average treatment effect estimates, the use of Vitamins C and E reduced the risk of mortality (risk difference [RD]: -0.07; 95% confidence interval [CI]: -0.14--0.003) and reduced the length of ICU stay (RD -1.77 95% CI:-3.71-0.16). Furthermore, our results showed that GOS-E was improved significantly (RD: 0.09, 95% CI : 0.03-0.16).

Conclusion

Our study suggests that using Vitamins C and E could decrease mortality and length of ICU stay and improve the GOS-E score and functions of the patients with severe TBI. As they are safe and inexpensive medications, they can be used in routine practice in ICUs to improve the outcomes of TBI patients.

Survival benefit of pancreatic enzyme replacement therapy in patients undergoing treatment of pancreatic neuroendocrine tumours

BACKGROUND

Treatment with somatostatin analogues (SSAs) or pancreaticoduodenectomy frequently causes malnutrition-inducing pancreatic exocrine insufficiency. This single-centre retrospective cohort study aimed to establish whether pancreatic enzyme replacement therapy (PERT) improves survival or nutritional status in SSA or pancreaticoduodenectomy-treated patients with pancreatic neuroendocrine tumours (pNETs).

METHODS

SSA and/or pancreaticoduodenectomy-treated patients with pNETs, diagnosed between 2009 and 2019, (n = 77) were retrospectively identified from departmental databases. Data was sourced from clinical records. Overall survival and percentage monthly weight changes were compared between PERT-treated (n = 45) and non-PERT-treated (n = 32) patients.

RESULTS

PERT-treated patients experienced significantly greater median monthly weight gain (+0.01% vs -0.10%, p = 0.038) and 5-year survival (81% vs 51%, p = 0.007). PERT was not, however, independently associated with survival (Hazard ratio 0.47, 95% CI 0.14-1.62, p = 0.232). Considering SSA-treated patients (n = 50) only, PERT-treated patients (n = 24) showed numerically but non-significantly improved monthly weight gain (+0.04% vs -0.18%, p = 0.139) and median survival (55.5, 95% CI 10.2-100.7 vs 42.4, 95% CI 11.7-73.2 months, p = 0.082).

CONCLUSION

PERT may improve survival and nutrition in SSA and pancreaticoduodenectomy-treated patients with pNETs, however, low patient numbers precluded the reliable mitigation of confounding in this study. A further multi-centre study is required to define the benefits of PERT in this population.

Reactivity of Vitamin E as an Antioxidant in Red Meat and the Stomach Medium

The stomach is a bioreactor and an important intersection of biochemical reactions that affect human health. Lipid peroxidation of meat in the stomach medium generates malondialdehyde (MDA), which is absorbed from the gut into human plasma and modifies low-density lipoprotein (LDL) to MDA-LDL. We found in the stomach medium (pH 3.0) a high antioxidant activity of vitamin E against meat lipid peroxidation, almost 35-fold higher than at pH 6.3. In the stomach medium, the antioxidant activity of vitamin E on meat lipid peroxidation was 20-fold higher than that of catechin. Vitamin E, at pH 3.0, acts synergistically with metmyoglobin (MbFe⁺³), as a peroxidase/antioxidant couple. The synergistic effect of MbFe⁺³/vitamin E was almost 150-fold higher than the antioxidant effect achieved by MbFe⁺³/catechin. The meat antioxidant activity was maintained continuously by addition of a low concentration of vitamin E, catechin, and vitamin C, preventing the propagation of lipid oxidation, reactive aldehyde generation, and the loss of vitamin E.

Are Nutraceuticals Effective in COVID-19 and Post-COVID Prevention and Treatment?

The beginning of the end or the end of the beginning? After two years mastered by coronavirus disease 19 (COVID-19) pandemic, we are now witnessing a turnaround. The reduction of severe cases and deaths from COVID-19 led to increasing importance of a new disease called post-COVID syndrome. The term post-COVID is used to indicate permanency of symptoms in patients who have recovered from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Immune, antiviral, antimicrobial therapies, as well as ozone therapy have been used to treat COVID-19 disease. Vaccines have then become available and administered worldwide to prevent the insurgence of the disease. However, the pandemic is not over yet at all given the emergence of new omicron variants. New therapeutic strategies are urgently needed. In this view, great interest was found in nutraceutical products, including vitamins (C, D, and E), minerals (zinc), melatonin, probiotics, flavonoids (quercetin), and curcumin. This review summarizes the role of nutraceuticals in the prevention and/or treatment of COVID-19 disease and post-COVID syndrome.

Food Insecurity, Dietary Intakes, and Eating Behaviors in a Convenience Sample of Toronto Youth

BACKGROUND

Food insecurity has been shown to be associated with poor dietary quality and eating behaviors, which can have both short- and long-term adverse health outcomes in children. The objective was to investigate the food security status, dietary intakes, and eating behaviors in a convenience sample of youth participating in the Maple Leaf Sports Entertainment LaunchPad programming in downtown Toronto, Ontario.

METHODS

Youth aged 9-18 years were recruited to participate in the study. Food security status, dietary intakes, and eating behaviors were collected using parent- or self-reported questionnaires online.

RESULTS

Sixty-six youth (mean ± SD: 11.7 ± 1.9 years) participated in the study. The prevalence of household food insecurity was higher than the national average with at least one child under 18 years of age (27.7% vs. 16.2%). Dietary intake patterns were similar to the national trends with low intakes of fiber, inadequate intakes of calcium and vitamin D; and excess intakes of sodium, added sugar, and saturated fat. Despite a low prevalence of poor eating habits, distracted eating was the most frequently reported poor eating habit.

CONCLUSIONS

Although youth were at high risk for experiencing household food insecurity, inadequate dietary intake patterns were similar to the national trends. Our findings can be used to develop future programming to facilitate healthy dietary behaviors appropriate for the target community.

Dietary Intake and Genetic Background Influence Vitamin Needs during Pregnancy

Numerous approaches demonstrate how nutritional intake can be sufficient to ensure the necessary supply of vitamins. However, it is evident that not all vitamins are contained in all foods, so it is necessary either to combine different food groups or to use a vitamin supplement to be well-fed. During pregnancy, deficiencies are often exacerbated due to increased energy and nutritional demands, causing adverse outcomes in mother and child. Micronutrient supplementation could lead to optimal pregnancy outcomes being essential for proper metabolic activities that are involved in tissue growth and functioning in the developing fetus. In order to establish adequate vitamin supplementation, various conditions should be considered, such as metabolism, nutrition and genetic elements. This review accurately evaluated vitamin requirements and possible toxic effects during pregnancy. Much attention was given to investigate the mechanisms of cell response and risk assessment of practical applications to improve quality of life. Importantly, genetic studies suggest that common allelic variants and polymorphisms may play an important role in vitamin metabolism during pregnancy. Changes in gene expression of different proteins involved in micronutrients’ metabolism may influence the physiological needs of the pregnant woman.

Plasma Vitamin E and the Risk of First Stroke in Hypertensive Patients: A Nested Case-Control Study

Background: The association between plasma vitamin E levels and first stroke risk in men and women remains unclear. Objective: We aimed to examine the prospective association between plasma vitamin E and first stroke, and evaluate the effect modifiers for the association, among hypertensive patients. Design: The study sample was drawn from the China Stroke Primary Prevention Trial (CSPPT), which randomized a total of 20,702 hypertensive patients to a double-blind, daily treatment with either 10 mg enalapril and 0.8 mg folic acid or 10 mg enalapril alone. This nested case-control study, including 618 first stroke cases and 618 controls matched for age, sex, treatment group, and study site, was conducted after the completion of the CSPPT. Results: The median follow-up duration was 4.5 years. Among men, a significantly higher risk of first stroke (adjusted OR, 1.67; 95%CI: 1.01, 2.77) was found for those with plasma vitamin E ≥7.1 μg/mL (≥quartile 1) compared with those with plasma vitamin E < 7.1 μg/mL. Subgroup analyses further showed that the association between vitamin E (≥7.1 vs. <7.1 μg/mL) and first stroke in men was significantly stronger in non-drinkers (adjusted OR, 2.64; 95%CI: 1.41, 4.96), compared to current drinkers (adjusted OR, 0.84; 95% CI: 0.43, 1.66, P-interaction = 0.008). However, there was no significant association between plasma vitamin E and first stroke in women (P-interaction between sex and plasma vitamin E = 0.048). Conclusions: Among Chinese hypertensive patients, there was a statistically significant positive association between baseline plasma vitamin E and the risk of first stroke in men, but not in women. Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT00794885, Identifier: NCT00794885.

Redox Regulation of Lipid Mobilization in Adipose Tissues

Lipid mobilization in adipose tissues, which includes lipogenesis and lipolysis, is a paramount process in regulating systemic energy metabolism. Reactive oxygen and nitrogen species (ROS and RNS) are byproducts of cellular metabolism that exert signaling functions in several cellular processes, including lipolysis and lipogenesis. During lipolysis, the adipose tissue generates ROS and RNS and thus requires a robust antioxidant response to maintain tight regulation of redox signaling. This review will discuss the production of ROS and RNS within the adipose tissue, their role in regulating lipolysis and lipogenesis, and the implications of antioxidants on lipid mobilization.

A Systematic Review of Effects of Vitamin E on the Cardiovascular System

Vitamin E is a fat-soluble vitamin and an antioxidant that prevents the peroxidation of lipid in vitro. The antioxidant role of vitamin E in preventing adverse cardiovascular outcomes is controversial as some studies support it, while others reject it. Therefore, this review aims to determine whether there is an association between vitamin E and cardiovascular diseases (CVDs). An electronic search was done to find out relevant articles. Papers were shortlisted after the initial title and abstract screen. A full-text study was done, and inclusion and exclusion criteria were applied before the quality assessment of each paper was done. Only high-quality papers were selected for analysis. Full-text articles of the last ten years were included, while non-English articles, gray literature, and animal studies were excluded. The majority of the papers, including 75% of the total population in this review, suggested no role of vitamin E in preventing CVD and CVD mortality. Some studies also suggested that a high level of vitamin E can be associated with adverse cardiovascular outcomes. Thus, one should be prudent about taking vitamin E supplementation for cardiovascular risk prevention.

Nutritional approach for increasing public health during pandemic of COVID-19: A comprehensive review of antiviral nutrients and nutraceuticals

Background: The novel coronavirus (COVID-19) is considered as the most life-threatening pandemic disease during the last decade. The individual nutritional status, though usually ignored in the management of COVID-19, plays a critical role in the immune function and pathogenesis of infection. Accordingly, the present review article aimed to report the effects of nutrients and nutraceuticals on respiratory viral infections including COVID-19, with a focus on their mechanisms of action. Methods: Studies were identified via systematic searches of the databases including PubMed/ MEDLINE, ScienceDirect, Scopus, and Google Scholar from 2000 until April 2020, using keywords. All relevant clinical and experimental studies published in English were included. Results: Protein-energy malnutrition (PEM) is common in severe respiratory infections and should be considered in the management of COVID-19 patients. On the other hand, obesity can be accompanied by decreasing the host immunity. Therefore, increasing physical activity at home and a slight caloric restriction with adequate intake of micronutrients and nutraceuticals are simple aids to boost host immunity and decrease the clinical manifestations of COVID-19. Conclusion: The most important nutrients which can be considered for COVID-19 management are vitamin D, vitamin C, vitamin A, folate, zinc, and probiotics. Their adequacy should be provided through dietary intake or appropriate supplementation. Moreover, adequate intake of some other dietary agents including vitamin E, magnesium, selenium, alpha linolenic acid and phytochemicals are required to maintain the host immunity.

NAFLD, Insulin Resistance, and Diabetes Mellitus Type 2

Nonalcoholic fatty liver disease is a condition defined by fat accumulation in hepatocytes not promoted by excessive alcohol consumption. It is highly prevalent and is strongly associated with insulin resistance, metabolic syndrome, and diabetes type II. Insulin resistance plays a crucial role in the multifactorial etiopathogenesis of this condition leading to accumulation of free fatty acids in the liver cells, thus causing lipotoxicity, inflammation, and fibrosis. In this review, we will focus on currently known pathogenesis of nonalcoholic fatty liver disease. Numerous investigation strategies are available to establish the diagnosis, from biochemical markers and ultrasound to various molecular and advanced imaging techniques and liver biopsy. Prevention is crucial. However, effective and promising therapies are strongly demanded.

Table olives and health: a review

Table olives, a product of olive tree (Olea europaea L.), is an important fermented product of the Mediterranean Diet. Agronomical factors, particularly the cultivar, the ripening stage and the processing method employed are the main factors influencing the nutritional and non-nutritional composition of table olives and their organoleptic properties. The important nutritional value of this product is due to its richness in monounsaturated fat (MUFA), mainly oleic acid, fibre and vitamin E together with the presence of several phytochemicals. Among these, hydroxytyrosol (HT) is the major phenolic compound present in all types of table olives. There is a scarcity of in vitro, in vivo and human studies of table olives. This review focused comprehensively on the nutrients and bioactive compound content as well as the health benefits assigned to table olives. The possible health benefits associated with their consumption are thought to be primarily related to effects of MUFA on cardiovascular health, the antioxidant (AO) capacity of vitamin E and its role in protecting the body from oxidative damage and the anti-inflammatory and AO activities of HT. The influence of multiple factors on composition of the end product and the potential innovation in the production of table olives through the reduction of its final salt content was also discussed.

Effects of vitamin E on stroke: a systematic review with meta-analysis and trial sequential analysis

There are several previous studies on the association of vitamin E with prevention of stroke but the findings remain controversial. We have conducted a systematic review, meta-analysis together with trial sequential analysis of randomised controlled trials to evaluate the effect of vitamin E supplementation versus placebo/no vitamin E on the risk reduction of total, fatal, non-fatal, haemorrhagic and ischaemic stroke. Relevant studies were identified by searching online databases through Medline, PubMed and Cochrane Central Register of Controlled Trials. A total of 18 studies with 148 016 participants were included in the analysis. There was no significant difference in the prevention of total stroke (RR (relative risk)=0.98, 95% CI 0.92-1.04, p=0.57), fatal stroke (RR=0.96, 95% CI 0.77-1.20, p=0.73) and non-fatal stroke (RR=0.96, 95% CI 0.88-1.05, p=0.35). Subgroup analyses were performed under each category (total stroke, fatal stroke and non-fatal stroke) and included the following subgroups (types of prevention, source and dosage of vitamin E and vitamin E alone vs control). The findings in all subgroup analyses were statistically insignificant. In stroke subtypes analysis, vitamin E showed significant risk reduction in ischaemic stroke (RR=0.92, 95% CI 0.85-0.99, p=0.04) but not in haemorrhagic stroke (RR=1.17, 95% CI 0.98-1.39, p=0.08). However, the trial sequential analysis demonstrated that more studies were needed to control random errors. Limitations of this study include the following: trials design may not have provided sufficient power to detect a change in stroke outcomes, participants may have had different lifestyles or health issues, there were a limited number of studies available for subgroup analysis, studies were mostly done in developed countries, and the total sample size for all included studies was insufficient to obtain a meaningful result from meta-analysis. In conclusion, there is still a lack of statistically significant evidence of the effects of vitamin E on the risk reduction of stroke. Nevertheless, vitamin E may offer some benefits in the prevention of ischaemic stroke and additional well-designed randomised controlled trials are needed to arrive at a definitive finding. PROSPERO registration number: CRD42020167827.

Vitamins and Uterine Fibroids: Current Data on Pathophysiology and Possible Clinical Relevance

Uterine fibroid (UF) is the most common benign tumor pathology of the female reproductive organs. UFs constitute the main reason for a hysterectomy and hospitalization due to gynecological conditions. UFs consist of uterine smooth muscle immersed in a large amount of extracellular matrix (ECM). Genetic studies have demonstrated that UFs are monoclonal tumors originating from the myometrial stem cells that have underwent specific molecular changes to tumor initiating stem cells which proliferate and differentiate later under the influence of steroid hormones. There is growing interest in the role of micronutrients, for example, vitamins, in UFs. This article is a comprehensive review of publications regarding the available data concerning the role of vitamins in the biology and management of UFs. In summary, the results showed that some vitamins are important in the biology and pathophysiology of UFs. For example, vitamins A and D deserve particular attention following studies of their influence on the treatment of UF tumors. Vitamins B3, C, and E have not been as widely studied as the abovementioned vitamins. However, more research could reveal their potential role in UF biology.

Combined effect of high-dose vitamin A, vitamin E supplementation, and zinc on adult patients with diabetes: A randomized trial

In type 2 diabetes mellitus (T2DM), hyperglycemia leads to oxidative insult. Vitamins A and E have antioxidant potentials and may help in managing diabetes. The combined effect of high-dose vitamin A plus E supplementation with and without zinc on T2DM, has never been examined. Thus, this study aimed to evaluate and compare the effect of high-dose vitamin A plus E supplementation (AE) versus high-dose vitamin A plus E with zinc (AEZ), on different diabetic parameters. Ninety-eight patients with T2DM were randomized to receive either: 50,000 IU vitamin A and 100 mg vitamin E (AE group, N = 36), an equivalent dose of vitamin A and E combined with 25 mg zinc (AEZ group, N = 35), or no supplements (control group, N = 27) for three months. Compared to control, AEZ group showed significant reductions in fasting blood glucose, 2 h postprandial blood glucose, and glycated hemoglobin (HbA1c) with significant increases in homeostasis model assessment of beta-cell function and difference value of fasting insulin. Two hair loss cases were recorded in both treated groups. Although vitamin A needs dose moderation, these results suggest that, high-dose vitamin A plus E supplementation combined with zinc may improve glycemic control, β-cell function, and insulin secretion in adults with T2DM.

Role of the PNPLA3 polymorphism rs738409 on silymarin + vitamin E response in subjects with non-alcoholic fatty liver disease

BACKGROUND

non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in developed countries. Lifestyle changes are the pillar of the treatment, although a pharmacological approach is sometimes required in the case of a failure to respond/adhere to the diet.

OBJECTIVE

the aim of this study was to evaluate the effect of silymarin and the influence of the patatin-like phospholipase domain-containing protein 3 (PNPLA3) variant on the response to treatment in patients with NAFLD in a pilot study.

METHODS

a total of 54 patients with a NAFLD proven biopsy were enrolled in an open prospective study and were treated with Eurosil 85® (silymarin + vitamin E) for six months. Biochemical parameters and cardiovascular risk factors (diabetes mellitus, dyslipidemia, hypertriglyceridemia, arterial hypertension and HOMA-IR > 2.5) were recorded before and after six months of treatment. Non-invasive indexes (fatty liver index, lipid accumulation product and NAFLD-fibrosis score) were also calculated. The rs738409 PNPLA3 gene polymorphism status was also determined.

RESULTS

significant statistical changes from baseline values after six months of treatment were observed in transaminases levels but not in non-invasive index markers. Twenty patients (37.1%) were G allele carriers and had a higher percentage of lobular inflammation and ballooning on the basal liver biopsy. Patients with the G allele had a smaller decrease in transaminases levels after treatment with silymarin + vitamin E than non-G-allele carriers.

CONCLUSIONS

treatment with silymarin + vitamin E produced a decrease in transaminases after six months of treatment without an accompanying weight loss. PNPLA3 G-allele carriers responded poorly to the treatment.

An allele of ZmPORB2 encoding a protochlorophyllide oxidoreductase promotes tocopherol accumulation in both leaves and kernels of maize

Phytol is one of the key precursors for tocopherol synthesis in plants, however, the underlying mechanisms concerning the accumulation of tocopherol remain poorly understood. In this study, qVE5, a major QTL affecting tocopherol accumulation in maize kernels was identified via a positional cloning approach. qVE5 encodes a protochlorophyllide oxidoreductase (ZmPORB2), which localizes to the chloroplast. Overexpression of ZmPORB2 increased tocopherol content in both leaves and kernels. Candidate gene association analysis identified a 5/8-bp insertion/deletion (InDel058) in the 5' untranslated region (UTR) as the causal polymorphism in affecting ZmPORB2 expression and being highly associated with tocopherol content. We showed that higher expression of ZmPORB2 correlated with more chlorophyll metabolites in the leaf following pollination. RNA-sequencing and metabolic analysis in near isogenic lines (NILs) support that ZmPORB2 participates in chlorophyll metabolism enabling the production of phytol, an important precursor of tocopherol. We also found that the tocopherol content in the kernel is mainly determined by the maternal genotype, a fact that was further confirmed by in vitro culture experiments. Finally, a PCR-based marker based on Indel058 was developed in order to facilitate the high tocopherol (vitamin E) maize breeding.

Circulating Vitamin E Levels and Risk of Coronary Artery Disease and Myocardial Infarction: A Mendelian Randomization Study

Observational studies have reported a cardioprotective effect of vitamin E whereas intervention trials failed to confirm its beneficial effects, and even some reported adverse effects of vitamin E supplements on coronary artery disease (CAD). To clarify, we conducted a two-sample mendelian randomization study to investigate causal association of vitamin E with the risk of CAD. Three single nucleotide polymorphisms (SNPs) identified in a genome-wide analysis study including 7781 individuals of European descent, rs964184, rs2108622, and rs11057830 were used as the genetic instruments for vitamin E. Data for CAD/myocardial infarction (MI) were available from Coronary ARtery DIsease Genome wide Replication and Meta-analysis (CARDIoGRAM) plus The Coronary Artery Disease (C4D) Genetics consortium. The effect of each SNP on CAD/myocardial infarction (MI) was weighted by its effect on serum vitamin E (mg/L), and results were pooled to give a summary estimates for the effect of increased vitamin E on risk of CAD/MI. Based on 3 SNPs each 1 mg/L increase in vitamin E was significantly associated with CAD (odds ratio (OR) 1.05, 95% confidence interval (CI) 1.03–1.06), MI (OR 1.04, 95% CI 1.03–1.05), elevated low-density lipoprotein cholesterol (0.021 standard deviations (SD), 95% CI 0.016, 0.027), triglycerides (0.026 SD, 95% CI 0.021, 0.031), and total cholesterol (0.043 SD, 95% CI 0.038, 0.048) and lower levels of high-density lipoprotein cholesterol (−0.019 SD 95% CI −0.024, −0.014). Our findings indicate that higher vitamin E may increase the risk of CAD/MI and the safety and efficacy of vitamin E supplementation use should be reevaluated.

Vitamin E status in healthy population in Asia: A review of current literature

Vitamin E is a lipid soluble antioxidant which mainly circulates as α-tocopherol in the human plasma. Its deficiency is associated with ataxia, neuropathy, anaemia and several other health conditions. Although substantial data on vitamin E status has been published worldwide, there is paucity of data on the extent of deficiency from most Asian countries, including India. Part of the problem is lack of validated biomarkers for vitamin E and no consensus on cut offs for defining deficiency and sufficiency. Thus, interpretation of the data on the vitamin E status is difficult. Limited available data from 31 studies on vitamin E status in healthy people from Asia, the most populated continent, has been collated for the purpose of this review. Broadly, the results suggest inadequate vitamin E status in most age groups, with the prevalence of deficiency reaching 67%, 80%, 56% and 72% in infants, children and adolescents, adults, elderly and pregnant women, respectively, based on varying cut offs. The findings are not surprising as both, vitamin E intakes and its status have not received too much attention in the past. Lack of conclusive data accentuates the need for more research on the vitamin E status across all age groups and to define age, gender and physiological state specific cut offs for vitamin E levels.

Physiological impacts of pollution exposure in seabird's progeny nesting in a Mediterranean contaminated area

Aquatic wildlife is exposed through trophic transfer of hazardous substances to several threats inducing physiological impairments. We aimed at assessing the impact of contamination in one of the hot spots of pollution along Mediterranean coasts, the gulf of Gabes in Tunisia, on Common tern Sterna hirundo, a piscivorous top predator bird. Firstly, we compared the reproductive effort of breeding adults through clutch size distribution in three sites with different levels of pollution. Then, a battery of genotoxicity and oxidative stress biomarkers was carried out to assess physiological impairments in chicks. While defense mechanisms showed a depletion, lipid peroxidation and genotoxicity increased significantly according to pollution level. The multi-biomarker approach used here, discriminated chicks according to contamination degree of their nesting sites. Increases in genotoxicity and oxidative stress were correlated to a decrease in chick body mass known to lead to long-term impacts on juvenile survival and recruitment in birds.

γ-Tocotrienol Suppression of the Warburg Effect Is Mediated by AMPK Activation in Human Breast Cancer Cells

Cancer cell metabolism is characterized by aerobic glycolysis or the "Warburg effect". Enhanced Akt signaling is associated with activation of various downstream enzymes involved in the glycolytic process, whereas activation of 5'-AMP-activated kinase (AMPK) acts to terminate energy expending mechanisms and decrease glycolytic enzyme expression. Studies were conducted to determine if the anticancer effects of γ-tocotrienol, are mediated through a suppression in aerobic glycolysis. Results show that treatment with 0-7 μM γ-tocotrienol throughout a 4-day culture period resulted in a dose-responsive increase in AMPK activation, and corresponding decrease in Akt activity in human MCF-7 and MDA-MB-231 breast cancer cells. γ-Tocotrienol treatment was also found to induce a dose-responsive decrease in phosphorylated-Fox03 (inactivated), a transcription factor that acts to inhibit in the levels of glycolytic enzyme, and this decrease was associated with a reduction in glycolytic enzyme levels and activity, as well as glucose consumption in these cells. PCR microarray analysis shows that γ-tocotrienol treatment decreases the expression of genes associate with metabolic signaling and glycolysis in MCF-7 and MDA-MB-231 breast cancer cells. In summary, these findings demonstrate that the anticancer effects of γ-tocotrienol are mediated, at least in part, by a suppression in the Warburg effect.

Increased concentration of serum MDA, decreased antioxidants and altered trace elements and macro-minerals are linked to obesity among Bangladeshi population

BACKGROUND AND OBJECTIVE

Obesity is an emerging public health concern in Bangladesh. This study aimed to find the levels of the serum malondialdehyde (MDA), non-enzymatic antioxidants (vitamin A, C and E), trace elements (zinc and iron) and macro-minerals (calcium, potassium and sodium) in obesity and its action in disease advancement.

METHODS

Level of lipid peroxidation was estimated by measurement of the serum concentrations of malondialdehyde (MDA). Vitamin A and E concentration was found by RP-HPLC method and vitamin C was assessed for serum ascorbic acid by UV spectrophotometric method. Serum trace elements (Zn and Fe) and macro-minerals (Na, K and Ca) were estimated by Atomic Absorption Spectroscopy (AAS).

RESULTS

Our study observed significantly elevated concentrations of MDA (p < 0.001) and depleted concentrations of antioxidants (vitamin A, E and C) (p < 0.05) in the patient than control group. Analysis of serum trace elements (Zn and Fe) and macro-minerals (Na, K and Ca) and found that the mean values of Zn, Fe, Na, K and Ca were 0.39 ± 0.02 and 0.43 ± 0.03, 3284.81 ± 34.51, 162.18 ± 3.72, 44.62 ± 2.13 mg/L for the patient and 0.91 ± 0.13, 0.88 ± 0.06, 2562.74 ± 95.92, 243.58 ± 8.97, 87.66 ± 2.10 mg/L for the controls, consequently. There was a substantial difference in trace elements and macro-minerals between the patients and controls (p < 0.001).

CONCLUSION

Our study proposes that increased serum concentrations of MDA and decreased non-enzymatic antioxidant and altered trace elements and macro-minerals are powerfully related with obesity.

Benefits of Vitamins in the Treatment of Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disease in the elderly, which is clinically characterized by bradykinesia, resting tremor, abnormal posture balance, and hypermyotonia. Currently, the pathogenic mechanism of PD remains unclear. Numerous clinical studies as well as animal and cell experiments have found a certain relationship between the vitamin family and PD. The antioxidant properties of vitamins and their biological functions of regulating gene expression may be beneficial for the treatment of PD. Current clinical evidence indicates that proper supplementation of various vitamins can reduce the incidence of PD in the general population and improve the clinical symptoms of patients with PD; nevertheless, the safety of regular vitamin supplements still needs to be highlighted. Vitamin supplementation may be an effective adjuvant treatment for PD. In this review, we summarized the biological correlations between vitamins and PD as well as the underlying pathophysiological mechanisms. Additionally, we elaborated the therapeutic potentials of vitamins for PD.

Identification and expression analysis of alpha tocopherol transfer protein in chickens fed diets containing different concentrations of alpha-tocopherol

Among the eight forms of vitamin E, the liver preferentially releases α-tocopherol into the circulation and it is distributed to the non-liver tissues. In the hepatocytes, alpha tocopherol transfer protein (TTPA) specifically recognizes α-tocopherol with 2R-configuration and facilitates its intracellular transfer. The identification and characterization of TTPA expression have not been demonstrated in avian species. Therefore, the objectives of this study were to identify avian TTPAs, to compare the sequence conservation, phylogenetic relationship, protein interactions, and disease associations of chicken TTPA with those of human and vertebrate TTPA, and to characterize the tissue expression of the TTPA gene in chickens fed diets supplemented with different amounts of α-tocopherol. Our results suggest that the chicken TTPA was highly conserved with the human and vertebrate TTPA, and consisted of a cellular retinaldehyde binding protein and TRIO guanine exchange factor (CRAL_TRIO) domain. Feeding diets supplemented with increasing amounts of α-tocopherol (25 IU/Kg, 50 IU/Kg, or 100 IU/Kg) to broiler chickens had no effects on growth performance compared with feeding basal diets containing no supplemental α-tocopherol. The expression of TTPA gene was detected high in the liver of chickens in response to dietary α-tocopherol concentrations, whereas its expression was very low or undetectable in the non-liver tissues. In conclusion, the chicken TTPA protein sequence is highly conserved with other avian and vertebrate TTPA protein sequences. The higher expression of TTPA gene in the chicken liver in response to dietary α-tocopherol concentrations may suggest its crucial role in transporting α-tocopherol in the chicken liver.

Vitamin E intake and risk of stroke: a meta-analysis

Findings from observational studies on the associations between vitamin E intake and stroke risk remain controversial, and the dose–response relationship between vitamin E intake and risk of stroke remains to be determined. We conducted a meta-analysis of prospective studies aiming to clarify the relationships between vitamin E intake and risk of stroke. Relevant studies were identified by searching online databases through to June 2018. We computed summary relative risks (RR) with corresponding 95 % CI. Among 3156 articles retrieved from online databases and relevant bibliographies, nine studies involving 3284 events and 220 371 participants were included in the final analyses. High dietary vitamin E intake was inversely associated with the risk of overall stroke (RR=0·83, 95 % CI 0·73, 0·94), and with the risk of stroke for individuals who were followed-up for <10 (RR=0·84, 95 % CI 0·72, 0·91). There was a non-linear association between dietary vitamin E intake and stroke risk (P=0·0249). Omission of any single study did not alter the summary result. In conclusion, this meta-analysis suggests that there is a significant inverse relationship between dietary vitamin E intake and stroke risk. This meta-analysis provides evidence that a higher dietary vitamin E intake is associated with a lower stroke risk.

Non-alcoholic steatohepatitis associated with Netherton syndrome

A 21-year-old man with Netherton syndrome underwent investigation of a persistently elevated serum alanine transaminase, detected on routine monitoring. He drank no alcohol, was not diabetic or overweight (body mass index 23 kg/m2) and had no clinical features of liver dysfunction. A FibroScan yielded an elevated result of 9.3 kPa. An ultrasound guided liver biopsy showed histological features consistent with non-alcoholic steatohepatitis, with activity score of 4 and fibrosis stage of 3. The patient was started on vitamin E supplementation and remains under surveillance.

Dietary Antioxidants, Circulating Antioxidant Concentrations, Total Antioxidant Capacity, and Risk of All-Cause Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Observational Studies

The associations of various dietary or circulating antioxidants with the risk of all-cause mortality in the general population have not been established yet. A systematic search was performed in PubMed and Scopus, from their inception up to October 2017. Prospective observational studies reporting risk estimates of all-cause mortality in relation to dietary intake and/or circulating concentrations of antioxidants were included. Random-effects meta-analyses were conducted. Forty-one prospective observational studies (total n = 507,251) involving 73,965 cases of all-cause mortality were included. The RRs of all-cause mortality for the highest compared with the lowest category of circulating antioxidant concentrations were as follows: total carotenes, 0.60 (95% CI: 0.46, 0.74); vitamin C, 0.61 (95% CI: 0.53, 0.69); selenium, 0.62 (95% CI: 0.45, 0.79); β-carotene, 0.63 (95% CI: 0.57, 0.70); α-carotene, 0.68 (95% CI: 0.58, 0.78); total carotenoids, 0.68 (95% CI: 0.56, 0.80); lycopene, 0.75 (95% CI: 0.54, 0.97); and α-tocopherol, 0.84 (95% CI: 0.77, 0.91). The RRs for dietary intakes were: total carotenoids, 0.76 (95% CI: 0.66, 0.85); total antioxidant capacity, 0.77 (95% CI: 0.73, 0.81); selenium, 0.79 (95% CI: 0.73, 0.85); α-carotene, 0.79 (95% CI: 0.63, 0.94); β-carotene, 0.82 (95% CI: 0.77, 0.86); vitamin C, 0.88 (95% CI: 0.83, 0.94); and total carotenes, 0.89 (95% CI: 0.81, 0.97). A nonsignificant inverse association was found for dietary zinc, zeaxanthin, lutein, and vitamin E. The nonlinear dose-response meta-analyses demonstrated a linear inverse association in the analyses of dietary β-carotene and total antioxidant capacity, as well as in the analyses of circulating α-carotene, β-carotene, selenium, vitamin C, and total carotenoids. The association appeared to be U-shaped in the analyses of serum lycopene and dietary vitamin C. The present study indicates that adherence to a diet with high antioxidant properties may reduce the risk of all-cause mortality. Our results confirm current recommendations that promote higher intake of antioxidant-rich foods such as fruit and vegetables.

Determination of tocopherols and tocotrienols in human breast adipose tissue with the use of high performance liquid chromatography-fluorescence detection

Tocopherols and tocotrienols have been extensively studied owing to their anticancer potential, especially against breast cancer. Therefore, the aim of this study was to quantitatively determine tocochromanols in human breast adipose tissue with the use of HPLC-FLD. The sample preparation procedure included homogenization and solvent extraction with isopropanol-ethanol-0.1% formic acid mixture prior to solid-phase extraction. After implementation of central composite design, satisfactory separation of all eight target compounds was achieved within 10.5 min. Chromatographic runs were carried out with the use of a naphthylethyl chromatographic column with methanol-water mixture (89:11, v/v) as the mobile phase. Fluorescence detection of tocochromanols was performed with excitation and emission wavelengths 298 and 330 nm, respectively. The method was validated in terms of linearity, carryover, recovery, precision, accuracy and stability. Extraction yield was also determined for accurate evaluation of vitamin E content in human breast adipose tissue samples. Finally, concentrations of particular tocochromanols compounds were assessed in human breast adipose tissue samples obtained from 99 patients, including women with breast cancer, healthy volunteers and deceased women who had died as a result of accidents. The raw data was transformed according to the newly developed equation for accurate estimation of the concentrations of tocochromanols in breast adipose tissue samples. Results obtained in the study indicated that the proposed analytical assay could be useful in breast cancer research.

Ionization of tocopherols and tocotrienols in atmospheric pressure chemical ionization

RATIONALE

Tocopherols and tocotrienols are chemical compounds insusceptible to the ionization process under atmospheric pressure conditions. Therefore, the selection of the optimal ion source settings for their quantification requires special attention. The aim of this study was to analyse the influence of the APCI source parameters on the response of tocochromanols and two related compounds.

METHODS

Standard solutions of target compounds were injected on the high-performance liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometry (HPLC/APCI-MS/MS) system separately and analysed with 30 randomly selected ion source settings. The obtained responses were modelled by multivariate linear regression with least absolute shrinkage and selection operator. The developed models were used to choose the best APCI conditions.

RESULTS

Multivariate linear models were built for eight tocochromanols, trolox and BHT. The APCI settings derived from the models did not increase the peak areas obtained for T and T3 during the ionization process. Ionization conditions based on models for trolox and BHT improved analytical responses by 12-36% and 4-32%, respectively. The application of the ion source settings optimal for trolox and BHT to tocochromanols did not result in better analytical responses.

CONCLUSIONS

The ionization pattern of tocochromanols in the APCI source is problematic and should be further investigated. Modelling methodology for response improvement presented in this study can be applied in similar studies.

Cutis laxa, exocrine pancreatic insufficiency and altered cellular metabolomics as additional symptoms in a new patient with ATP6AP1-CDG

Congenital disorders of glycosylation (CDG) are genetic defects in the glycoconjugate biosynthesis. >100 types of CDG are known, most of them cause multi-organ diseases. Here we describe a boy whose leading symptoms comprise cutis laxa, pancreatic insufficiency and hepatosplenomegaly. Whole exome sequencing identified the novel hemizygous mutation c.542T>G (p.L181R) in the X-linked ATP6AP1, an accessory protein of the mammalian vacuolar H⁺-ATPase, which led to a general N-glycosylation deficiency. Studies of serum N-glycans revealed reduction of complex sialylated and appearance of truncated diantennary structures. Proliferation of the patient's fibroblasts was significantly reduced and doubling time prolonged. Additionally, there were alterations in the fibroblasts' amino acid levels and the acylcarnitine composition. Especially, short-chain species were reduced, whereas several medium- to long-chain acylcarnitines (C14-OH to C18) were elevated. Investigation of the main lipid classes revealed that total cholesterol was significantly enriched in the patient's fibroblasts at the expense of phophatidylcholine and phosphatidylethanolamine. Within the minor lipid species, hexosylceramide was reduced, while its immediate precursor ceramide was increased. Since catalase activity and ACOX3 expression in peroxisomes were reduced, we assume an ATP6AP1-dependent impact on the β-oxidation of fatty acids. These results help to understand the complex clinical characteristics of this new patient.

Antioxidant effect of peony seed oil on aging mice

d-galactose was injected into mice of ages 4-5 months, and peony seed oil was administered using an oral gavage to assess its possible anti-aging functions. The content of malondialdehyde (MDA) and the activities of monoamine oxidase (MAO), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) in the brain and liver of these mice were determined using biochemical kits. The significance of the differences in the content of the components associated with aging and anti-aging among each group was analyzed statistically. The MDA content and activities of MAO in the brain and liver of mice in the peony seed oil group were significantly lower than those in the aging group. The activities of GSH-Px, Cu/Zn-SOD, and Mn-SOD in the brain and liver of mice in the peony seed oil group were very significantly higher than those in the aging group. Peony seed oil was determined to have an obvious anti-aging function.

Vitamin E Deficiency and Oxidative Status are Associated with Prediabetes in Apparently Healthy Subjects

BACKGROUND

Previous studies have indicated that vitamin E deficiency and oxidative stress affect the beta cell function. Hence, the aim of this study was to determine the association between vitamin E deficiency and oxidative status with prediabetes in apparently healthy subjects.

METHODS

Apparently healthy men and women aged 18-65 years were enrolled in a case-control study. Individuals with new diagnosis of prediabetes were considered as cases and compared with a control group of individuals with normal glucose tolerance. Smoking, alcohol intake, pregnancy, diabetes, kidney disease, liver disease, cardiovascular disease, malignancy, glucocorticoid treatment and consumption of lipid-lowering drugs, antioxidants and vitamin supplements were exclusion criteria. Vitamin E deficiency was defined by serum levels of α-tocopherol <11.6 μmol/L, oxidative status was assessed by total antioxidant capacity and lipid peroxidation, and prediabetes was considered by the presence of impaired fasting glucose and/or impaired glucose tolerance.

RESULTS

A total of 148 subjects were allocated into the case (n = 74) and control (n = 74) groups. The frequency of vitamin E deficiency was higher in the case group (41.8%) compared with the control group (35.1%), p = 0.03. The logistic regression analysis adjusted by age, waist circumference and body mass index, revealed a significant association between vitamin E deficiency (OR 3.23; 95% CI: 1.34-7.79, p = 0.009), lipoperoxidation (OR 2.82; CI 95%: 1.42-5.59, p = 0.003) and total antioxidant capacity (OR 0.93; CI 95%: 0.90-0.96, p <0.001) with prediabetes.

CONCLUSIONS

Results of the present study suggest that both vitamin E deficiency and oxidative status are associated with prediabetes in apparently healthy subjects.

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.