Vitamin E (α-tocopherol) consumption influences gut microbiota composition

Choi Y, Lee S, Kim S, Lee J, Ha J, Oh H, Lee Y, Kim Y, Yoon Y

Int J Food Sci Nutr. 2019 Jul 12:1-5. doi: 10.1080/09637486.2019.1639637. [Epub ahead of print]

Abstract

This study evaluated if vitamin E consumption affects gut microbiota. Mice were grouped into control, low vitamin E (LV), and high vitamin E (HV). LV and HV were fed DL-α-tocopherol at 0.06 mg/20 g and 0.18 mg/20 g of body weight per day, respectively, for 34 days. Body weight of mice was measured before and after vitamin E treatment. Animals were sacrificed, liver, spleen, small intestine and large intestine collected, and weight and length were measured. Composition of gut microbiota was determined by microbiome analysis. Spleen weight index of LV was the highest. However, liver weight indices and intestinal lengths were not different. Body weights of LV group were higher than those of control. Ratio of Firmicutes to Bacteroidetes was different in LV compared to control and HV. These results indicate that low-level consumption of vitamin E increases spleen and body weight, and changes gut microbiota.

Choe MS, Yeo HC, Bae CM, Han HJ, Baek KM, Kim JS, Lim KS, Shin IS, Chang WC, Yun SP, Lee HJ, Lee MY

Cell Biol Int. 2019 Jul 10. doi: 10.1002/cbin.11200. [Epub ahead of print]

Abstract

Cardiac differentiation of human pluripotent stem cells may be induced under chemically defined conditions, wherein the regulation of Wnt/β-catenin pathway is often desirable. Here, we examined the effect of trolox, a vitamin E analog, on the cardiac differentiation of human embryonic stem cells (hESCs). Trolox significantly enhanced cardiac differentiation in a time- and dose-dependent manner after the mesodermal differentiation of hESCs. Trolox promoted hESC cardiac differentiation through its inhibitory activity against the Wnt/β-catenin pathway. This study demonstrates an efficient cardiac differentiation method and reveals a novel Wnt/β-catenin regulator.

Casati L, Pagani F, Limonta P, Vanetti C, Stancari G, Sibilia V

Eur J Nutr. 2019 Jul 6. doi: 10.1007/s00394-019-02047-9. [Epub ahead of print]

Abstract

PURPOSE:

Natural antioxidants are considered as promising compounds in the prevention/treatment of osteoporosis. We studied the ability of purified δ-tocotrienol (δ-TT) isolated from a commercial palm oil (Elaeis guineensis) fraction to protect osteoblast MC3T3-E1 and osteocyte MLO-Y4 cells against tert-butyl hydroperoxide (t-BHP)-induced oxidative damage and the mechanisms involved in its protective action in MC3T3-E1.

METHODS:

MC3T3-E1 and MLO-Y4 cells were treated with δ-TT (1.25-20 µg/ml for 2 h) followed by t-BHP at 250 µM or 125 µM for 3 h, respectively. MTT test was used to measure cell viability. Apoptotic cells were stained with Hoechst-33258 dye. Intracellular ROS levels were measured by dichlorofluorescein CM-DCFA. The OPT fluorimetric assay was used to detect the reduced glutathione to oxidized glutathione ratio (GSH/GSSG) contents.

RESULTS:

δ-TT significantly prevented the effects of t-BHP on cell viability and apoptosis reaching a maximum protective activity at 10 and 5 µg/ml in MC3T3-E1 and MLO-Y4 cells, respectively. This protective effect was due to a reduction of intracellular ROS levels and an increase in the defense systems shown by the increase in the GSH/GSSG. GSH loss induced by an inhibitor of GSH synthesis significantly reduced the δ-TT-positive effect on ROS levels. δ-TT prevention of oxidative damage was completely removed by combined treatment with the specific inhibitors of PI3K/AKT (LY294002) and Nrf2 (ML385).

CONCLUSIONS:

The δ-TT protective effect against oxidative damage in MC3T3-E1 cells is due to a reduction of intracellular ROS levels and an increase of the GSH/GSSG ratio, and involves an interaction between the PI3K/Akt-Nrf2 signaling pathways.

Nasef SM, Khozemy EE, Kamoun EA, El-Gendi H

Int J Biol Macromol. 2019 Jul 5;137:878-885. doi: 10.1016/j.ijbiomac.2019.07.033. [Epub ahead of print]

Abstract

Crosslinked hydrogel composite membranes based on polyvinyl alcohol (PVA) and chitosan-loaded AgNO₃ and vitamin E were prepared using gamma irradiation. Chitosan has been used as antimicrobial blend materials to provide further biocompatibility for the prepared composite hydrogel membranes. The crosslinking reaction between PVA and chitosan owing to gamma irradiation was verified and characterized by FTIR analysis, while the morphology of hydrogel composite membranes was investigated by SEM. Important parameters affecting on hydrogel membranes formation, such as copolymer concentration, irradiation dose, AgNO₃ concentration, plasticizer, and vitamin E of PVA/chitosan membranes were evaluated and discussed in details. In addition, the mechanical and thermal properties of hydrogel composite membranes were examined to evaluate the possibility of its application for wound dressings. The results revealed that the gelation (%) of hydrogel membranes increased dramatically with PVA composition, irradiation dose and glycerol content up to 20%; however, it decreased with AgNP incorporation due to the viscosity of copolymer composition is hyper-increased. The swelling ratio of composed hydrogel membranes decreased notably with increasing the radiation dose and incorporation of AgNP, due to reducing of the crosslinking degree of formed hydrogel membranes. PVA-Cs-Ag composed hydrogel membranes showed significant antimicrobial activity in particular against Streptococcus mutans due to the presence of AgNP in membranes, compared to other bacteria and fungi microbes. Thus, the PVA/chitosan/AgNO₃-Vit.E hydrogel composite membranes showed satisfactory properties for use as wound dressing materials.

Ivancovsky-Wajcman D, Fliss-Isakov N, Salomone F, Webb M, Shibolet O, Kariv R, Zelber-Sagi S

Dig Liver Dis. 2019 Jul 4. pii: S1590-8658(19)30662-0. doi: 10.1016/j.dld.2019.06.005. [Epub ahead of print]

Abstract

BACKGROUND & AIMS:

Although antioxidants have a protective potential in nonalcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH), there is limited evidence regarding the role of dietary intake of antioxidants. The aim was to test the association between dietary vitamins E and C intake and NAFLD, NASH and fibrosis markers.

METHODS:

Cross-sectional study of a large cohort of subjects undergoing colonoscopy. The presence of NAFLD was evaluated by ultrasonography. The level of steatosis was defined using SteatoTest, moderate-severe NASH using new quantitative NashTest and borderline-significant fibrosis ≥ F1-F2 using FibroTest. Nutritional intake was measured by food frequency questionnaire (FFQ).

RESULTS:

Overall, 789 subjects were included (52.6% men, age 58.83 ± 6.58 years), 714 had reliable FibroMax. Adjusting for BMI, dietary and lifestyle factors, the upper tertile of vitamin E intake/1000 Kcal was associated with lower odds of NASH (OR = 0.64, 0.43-0.94, P = 0.024). There was an inverse association between reaching the recommended vitamin E intake and NASH (OR = 0.48, 0.30-0.77, P = 0.002). The upper tertile of vitamin C intake/1000 Kcal was associated with lower odds of NAFLD and NASH (OR = 0.68, 0.47-0.99, P = 0.045; OR = 0.57, 0.38-0.84, P = 0.004, respectively). Both vitamins were related with the level of steatosis according to SteatoTest.

CONCLUSION:

Vitamin E and C intake may be protective from NAFLD-related liver damage.

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.

Rahimi Anbarkeh F, Nikravesh MR, Jalali M, Sadeghnia HR, Sargazi Z

Int J Fertil Steril. 2019 Jul;13(2):154-160. doi: 10.22074/ijfs.2019.5612. Epub 2019 Apr 27.

Abstract

BACKGROUND:

Diazinon (DZN) is an organophosphate pesticide, and nowadays this pesticide is mostly used in agriculture. In this study, we analyzed the effects of DZN and vitamin E (Vit E) on apoptosis and the proliferation of germ cells in rat testis.

MATERIALS AND METHODS:

In this experimental study, 30 male Wistar rats were divided into five groups (n=6 per group) consisting of control, sham (received olive oil), experimental group i (60 mg/kg DZN), experimental group ii (60 mg/kg DZN and 200 mg/kg Vit E), and experimental group iii (200 mg/kg Vit E). After six weeks, left testis of rats was removed for the detection of proliferative cell nuclear antigen (PCNA) and terminal deoxynucleotidyl transferase end-labeling (TUNEL).

RESULTS:

Compared with the control group, DZN in the experimental group i decreased the number of PCNA-positive cells and increased the number of TUNEL-positive cells (P<0.001). Vit E improved detrimental changes by the decrease in the rate of apoptosis and the increase in the proliferation of testicular germ cells (P<0.001).

CONCLUSION:

Vit E can decrease the number of TUNEL-positive cells and increase the number of PCNA-positive cells by the neutralization of the toxicity caused by DZN in the testicular tissue.