Vitamin E modifies high-fat diet-induced reduction of seizure threshold in rats: Role of oxidative stress

Alzoubi KH, Hasan ZA, Khabour OF, Mayyas FA, Al Yacoub ON, Banihani SA, Alomari MA, Alrabadi NN

Physiol Behav. 2019 Jul 1;206:200-205. doi: 10.1016/j.physbeh.2019.04.011. Epub 2019 Apr 13.

Abstract

There is increasing evidence that oxidative stress is a causal factor in different neurodegenerative disorders such as Alzheimer’s disease and epilepsy. High-fat diet (HFD) has been shown to induce oxidative stress and neuronal damage that may increase susceptibility to seizures. The present study was undertaken to investigate the relationships between vitamin E, a potent antioxidant, HFD, and chemically induced seizures, using the PTZ seizure model in rats. Animals were randomly assigned into four groups: control, HFD, vitamin E (Vit E), and high-fat diet with vitamin E (HFD + Vit E) group. Vitamin E and/or HFD were administered to animals for 6 weeks. Thereafter, PTZ seizure threshold was measured in control and treated rats, and different brain regions were analyzed for levels of oxidative stress biomarkers. Current results revealed a significant reduction in PTZ seizure threshold in rats consuming HFD, which could be prevented by vitamin E supplement. Alongside, vitamin E supplement prevented HFD induced changes in oxidative stress biomarkers and capacity enzymes. Therefore, current results suggest that prolonged consumption of HFD increases susceptibility to PTZ induced seizures, which may be related to HFD induced oxidative stress. This increase in the PTZ susceptibility could be prevented by the administration of vitamin E, probably through its antioxidant effect, particularly at the brain hippocampal region.

Altamura S, Vegi NM, Hoppe PS, Schroeder T, Aichler M, Walch A, Okreglicka K, Hültner L, Schneider M, Ladinig C, Kuklik-Roos C, Mysliwietz J, Janik D, Neff F, Rathkolb B, Hrabé de Angelis M, Buske C, da Silva AR, Muedder K, Conrad M, Ganz T, Kopf M, Muckenthaler MU, Bornkamm GW

Haematologica. 2019 Jun 27. pii: haematol.2018.212977. doi: 10.3324/haematol.2018.212977. [Epub ahead of print]

Abstract

Glutathione peroxidase 4 (GPX4) is unique as it is the only enzyme that can prevent detrimental lipid peroxidation in vivo by reducing lipid peroxides to the respective alcohols thereby stabilizing oxidation products of unsaturated fatty acids. During reticulocyte maturation, 15-lipoxygenase-mediated lipid peroxidation in humans and rabbits and by 12/15-lipoxygenase (ALOX15) in mice had been considered as the initiating event for the elimination of mitochondria which is now known to occur through mitophagy. Yet, genetic ablation of the Alox15 gene in mice failed to provide evidence for this hypothesis. We designed a different genetic approach to tackle this open conundrum. Since either other lipoxygenases or non-enzymatic autooxidative mechanisms may compensate for the loss of Alox15, we asked whether ablation of GPX4 in the hematopoietic system would result in perturbation of reticulocyte maturation. Quantitative assessment of erythropoiesis indices in the blood, bone marrow and spleen of chimeric mice with GPX4 ablated in hematopoietic cells revealed anemia with an increase in the fraction of erythroid precursor cells and reticulocytes. Additional dietary vitamin E depletion strongly aggravated the anemic phenotype. Despite strong extramedullary erythropoiesis reticulocytes failed to mature and accumulated large autophagosomes with engulfed mitochondria. GPX4-deficiency in hematopoietic cells led to systemic hepatic iron overload and simultaneous severe iron demand in the erythroid system. Despite extremely high erythropoietin and erythroferrone levels in the plasma, hepcidin expression remained unchanged. Conclusively, perturbed reticulocyte maturation in response to GPX4 loss in hematopoietic cells thus causes ineffective erythropoiesis, a phenotype partially masked by dietary vitamin E supplementation.

Cui H, Huang J, Lu M, Zhang Q, Qin W, Zhao Y, Lu X, Zhang J, Xi Z, Li R

Environ Pollut. 2019 Jun 26;252(Pt B):1519-1531. doi: 10.1016/j.envpol.2019.06.092. [Epub ahead of print]

Abstract

Some basic research has shown that nanomaterials can aggravate allergic asthma. However, its potential mechanism is insufficient. Based on the research that alumina nanopowder (nAl₂O₃) has been reported to cause lung tissue damage, the purpose of this study was to explore the relationship between nAl₂O₃ and allergic asthma as well as its molecular mechanism. In this study, Balb/c mice were sensitized with ovalbumin (OVA) to construct the allergic asthma model while intratracheally administered 0.5, 5 or 50 mg kg^-1·day^-1 nAl₂O₃ for 3 weeks. It was observed that exposure to nAl₂O₃ exacerbated airway hyperresponsiveness (AHR), airway remodeling, and inflammation cell infiltration, leading to lung function damage in mice. Results revealed that nAl₂O₃ could increase ROS levels and decrease GSH levels in lung tissue, promote the increases of the T-IgE, TGF-β, IL-1β and IL-6 levels, stimulate the overexpression of transcription factors GATA-3 and RORγt, decrease the levels of IFN-γ and IL-10 and increase the levels of IL-4 and IL-17A, resulting in the imbalance of Th1/Th2 and Treg/Th17 immune responses. In addition, antioxidant Vitamin E (Vit E) could alleviate asthma-like symptoms through blocking oxidative stress. The study displayed that exposure of nAl₂O₃ deteriorated allergic asthma through promoting the imbalances of Th1/Th2 and Treg/Th17.

Chai W, Maskarinec G, Franke AA, Monroe KR, Park SY, Kolonel LN, Wilkens LR, Le Marchand L, Cooney RV

Eur J Clin Nutr. 2019 Jun 26. doi: 10.1038/s41430-019-0460-7. [Epub ahead of print]

Abstract

BACKGROUND/OBJECTIVES:

γ-Tocopherol has unique properties that protect against nitrogen oxide-mediated cellular damage. To elucidate the potential role of γ-tocopherol in the aging process, we examined the associations of serum γ-tocopherol levels with all-cause and cause-specific mortality.

SUBJECTS/METHODS:

Among participants in the biorepository subcohort of the Multiethnic Cohort Study, pre-cancer diagnostic serum γ-tocopherol levels were measured in a subset of 3904 men and 4461 women. Of these, 22.7% of men and 13.5% of women died during a mean follow-up time of 9.6 ± 2.6 years. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) for mortality associated with γ-tocopherol were estimated by Cox proportional hazards regression.

RESULTS:

Positive associations of serum γ-tocopherol with all-cause, cancer, and cardiovascular disease mortality (CVD) (P_trend < 0.05) were detected after adjusting for age, race/ethnicity, and serum cholesterol levels. The respective HRs (95% CIs) for the highest versus the lowest sex-specific γ-tocopherol quartile were 1.43 (1.17-1.74), 1.79 (1.22-2.64), and 1.52 (1.10-2.11) for men and 1.58 (1.25-2.00), 1.59 (1.05-2.41), and 1.59 (1.07-2.37) for women. Associations remained significant for all-cause mortality among women after further adjusting for smoking variables and history of cancer, CVD, diabetes, and hypertension at cohort entry (highest vs. lowest γ-tocopherol quartile: HR = 1.38; 95% CI = 1.08-1.75; P_trend = 0.005). Overall, associations with all-cause mortality were consistent across race/ethnicity and were significant in three of ten sex-specific racial/ethnic groups in the fully adjusted models, with no interactions between ethnicity and γ-tocopherol.

CONCLUSIONS:

The positive association between γ-tocopherol and mortality suggests a potential physiological role for γ-tocopherol in response to pathological conditions.

Wallert M, Bauer J, Kluge S, Schmölz L, Chen YC, Ziegler M, Searle AK, Maxones A, Schubert M, Thürmer M, Pein H, Koeberle A, Werz O, Birringer M, Peter K, Lorkowski S

Redox Biol. 2019 Jun;24:101166. doi: 10.1016/j.redox.2019.101166. Epub 2019 Mar 12.

Abstract

The plant Garcinia kola is used in African ethno-medicine to treat various oxidation- and inflammation-related diseases but its bioactive compounds are not well characterized. Garcinoic acid (GA) is one of the few phytochemicals that have been isolated from Garcinia kola. We investigated the anti-inflammatory potential of the methanol extract of Garcinia kola seeds (NE) and purified GA, as a major phytochemical in these seeds, in lipopolysaccharide (LPS)-activated mouse RAW264.7 macrophages and its anti-atherosclerotic potential in high fat diet fed ApoE^-/- mice. This study outlines an optimized procedure for the extraction and purification of GA from Garcinia kola seeds with an increased yield and a purity of >99%. We found that LPS-induced upregulation of iNos and Cox2 expression, and the formation of the respective signaling molecules nitric oxide and prostanoids, were significantly diminished by both the NE and GA. In addition, GA treatment in mice decreased intra-plaque inflammation by attenuating nitrotyrosinylation. Further, modulation of lymphocyte sub-populations in blood and spleen have been detected, showing immune regulative properties of GA. Our study provides molecular insights into the anti-inflammatory activities of Garcinia kola and reveals GA as promising natural lead for the development of multi-target drugs to treat inflammation-driven diseases.

Ansariniya H, Hadinedoushan H, Javaheri A, Zare F

J Obstet Gynaecol. 2019 Jun 24:1-6. doi: 10.1080/01443615.2019.1601167. [Epub ahead of print]

Abstract

Endometriosis is an extremely heterogeneous disease and affects about ten percent of the female population during their reproductive years. Recent studies showed that endometriosis is an angiogenesis-dependent disease. Peritoneal macrophages are a well-characterised source of vascular endothelial growth factor (VEGF). The aim of this study was to determine the VEGF gene expression and production in peritoneal macrophages of patients with endometriosis under the effects of vitamins C and E in comparison with control. The lab trial study carried out on 50 patients undergoing laparoscopy and peritoneal fluid samples were collected from them. We compared the VEGF gene expression and production in peritoneal macrophages among groups by using real-time polymerase chain reaction and enzyme-linked immunosorbent assay methods, respectively. Our results showed that gene expressions influenced by vitamin C increased in different concentrations and incubation times, except for the incubation time after 48 h. In the case of vitamin E, this was evident with the exception of vitamin E 50 μM after 24 h and vitamin E 100 μM after 48 h. Our findings indicated that vitamin C and E in different concentrations and incubation times altered VEGF gene expression in the peritoneal macrophages but they had not affected on VEGF productions. Impact statement What is already known on this subject? Previous studies showed that antioxidants play a key role in the inhibition of oxidative stress-induced damages and the reduction of pelvic pain in patients with endometriosis. Vitamin E and vitamin C are the main components in neutralising free radicals. Also, antioxidant consumption such as vitamin C and vitamin E in women with endometriosis showed an inverse correlation between antioxidant intake and endometriosis pathology. What do the results of this study add? Vitamin C and E in different concentrations and times of incubation altered vascular endothelial growth factor gene expression and production in peritoneal macrophages. What are the implications of these findings for clinical practice and/or further research? Further studies are needed to determine the effects of C and E vitamins in different concentrations on vascular endothelial growth factor gene expression and production in peritoneal macrophages and the possible roles of these vitamins in treating endometriosis.

Tobias DK

Circ Res. 2019 Jun 21;125(1):41-42. doi: 10.1161/CIRCRESAHA.119.315285. Epub 2019 Jun 20.

Abstract

Huang et al of the ATBC study (Alpha-Tocopherol, Beta-Carotene Cancer Prevention) reported a significant relationship between serum α-tocopherol with lower risks of all-cause and cause-specific mortality in men. The ATBC cohort analysis included 29 092 male smokers aged 50 to 69 years at baseline, and 23 787 deaths were observed over 31 years of follow-up. Compared with the bottom 20% of serum α-tocopherol concentrations, men in the top 20% experienced a 22% lower risk of total mortality. Their results were robust to several sensitivity and subgroup analyses and persisted over 31 years of observation.

Huang J, Weinstein SJ, Yu K, Männistö S, Albanes D

Circ Res. 2019 Jun 21;125(1):29-40. doi: 10.1161/CIRCRESAHA.119.314944. Epub 2019 May 6.

Abstract

RATIONALE:

Although there has been a long-standing interest in the human health effects of vitamin E, a comprehensive analysis of the association between circulating vitamin E and long-term mortality has not been conducted.

OBJECTIVE:

Determine whether serum α-tocopherol (the predominant form of vitamin E) is related to long-term overall and cause-specific mortality and elucidate the dose-response relationships with better quantification of the associations.

METHODS AND RESULTS:

We conducted a biochemical analysis of 29 092 participants in the ATBC Study (Alpha-Tocopherol, Beta-Carotene Cancer Prevention) that originally tested vitamin E and β-carotene supplementation. Serum α-tocopherol was measured at baseline using high-performance liquid chromatography, and during a 30-year follow-up we identified 23 787 deaths, including deaths from cardiovascular disease (9867), cancer (7687), respiratory disease (2161), diabetes mellitus (119), injuries and accidents (1255), and other causes (2698). After adjusting for major risk factors, we found that men with higher serum α-tocopherol had significantly lower all-cause mortality (hazard ratios=0.83, 0.79, 0.75, and 0.78 for quintile 2 (Q2)-Q5 versus Q1, respectively; P_trend<0.0001), and significantly decreased mortality from cardiovascular disease, heart disease, stroke, cancer, respiratory disease, and other causes, with risk reductions from 17% to 47% for the highest versus lowest quintile. The α-tocopherol association with overall mortality was similar across subgroups of smoking intensity, years of smoking, alcohol consumption, trial supplementation, and duration of follow-up. The association was, however, significantly modified by baseline age and body mass index, with stronger inverse associations for younger men and men with a lower body mass index ( P_interaction≤0.006).

CONCLUSIONS:

In this long-term prospective cohort study, higher baseline serum α-tocopherol biochemical status was associated with lower risk of overall mortality and mortality from all major causes. Our data support the long-term health benefits of higher serum α-tocopherol for overall and chronic disease mortality and should be replicated in other more diverse populations.

Chen Y, Li C, Song P, Yan B, Yang X, Wu Y, Ma P

Food Chem Toxicol. 2019 Jun 20;132:110600. doi: 10.1016/j.fct.2019.110600. [Epub ahead of print]

Abstract

Diisononyl phthalate (DIDP) is commonly used as a plasticizer in industrial and consumer products, however, its toxicity remains unclear. This study investigated the possible involvement of oxidative stress in DIDP-induced liver and kidney toxicity. Liver function and kidney function, tissue lesions, oxidative stress biomarkers, inflammatory mediators and apoptosis factors were investigated in this study. The results showed that oral exposure to DIDP induced a marked increase in lever of alanine aminotransferase (ALT), aspartate aminotransferase (AST), urinary nitrogen (UREA) and creatinine (CREA), decrease in albumin (ALB) level, as well as causing hepatic and renal histopathological change. Investigation of the role of oxidative stress pathways showed that DBP exposure could lead to a significant increase in levels of reactive oxygen species (ROS), malondialdehyde (MDA), 8-hydroxy-2-deoxyguanosine (8-OHdG), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and nuclear factor-κB (NF-κB), while a decrease in glutathione (GSH) levels were observed. Administration of vitamin E to DIDP-treated mice restored these biochemical parameters to within normal levels, and resulted in less damage to livers and kidneys. Overall, these results suggest that the oxidative stress pathway is involved in DIDP-induced toxicity.

Hajizadeh K, Alizadeh Charandabi SM, Hasanzade R, Mirghafourvand M

Complement Ther Med. 2019 Jun;44:1-8. doi: 10.1016/j.ctim.2019.03.014. Epub 2019 Mar 22.

Abstract

OBJECTIVES:

A systematic review was conducted to assess the effect of vitamin E on the severity and duration of Cyclic Mastalgia compared to vitamin B6, fish oil, herbal medicines and placebo.

DESIGN:

A systematic review and meta-analysis of clinical trials.

METHODS:

A search was carried out in PubMed, Cochrane Library, Embase, Scopus and Google Scholar and Persian databases for articles published from 1980 to 2018. The data obtained were analyzed in RevMan and reported in forest plots. The Odds Ratio (OR) was used to find the effect for the dichotomous data and the Standardized Mean Difference (SMD) for the continuous data. The heterogeneity of the studies was assessed using I² and the Random Effects Model was used instead of the Fixed Effects Model if I²>25%.

RESULTS:

A total of 1051 titles and abstracts were extracted. Fourteen articles ultimately remained, and 11 of them were entered into the meta-analysis. The meta-analysis showed significant differences between vitamin E and placebo in the severity (SMD=-0.51; 95% CI=-0.21 to -0.82) and duration (MD=-1.47; 95% CI=-0.91 to -2.57) of cyclic mastalgia, although herbal medicines had a greater effect on the severity of mastalgia than vitamin E (SMD = 0.51, 95% CI = 0.06 to 0.96).

CONCLUSION:

Although herbal medicines are more effective than vitamin E, vitamin E reduces both the severity and duration of the disorder compared to placebos, which only reduce its severity, and can therefore be considered a treatment with minimum side-effects. Due to the high heterogeneity of the studies, the researchers recommend further research on the subject using a standard tool based on the CONSORT statement.