Measurements of Singlet Oxygen-Quenching Activity of Vitamin E Homologs and Palm Oil and Soybean Extracts in a Micellar Solution

Mukai K, Ishikawa E, Ouchi A, Nagaoka SI, Abe K, Suzuki T, Izumisawa K

Lipids. 2018 Aug 28. doi: 10.1002/lipd.12053. [Epub ahead of print]

Abstract

Recently, a new assay method that can quantify the singlet oxygen-absorption capacity (SOAC) of antioxidants (AO) and food extracts in homogeneous organic solvents has been proposed. In the present study, second-order rate constants (k_Q ) for the reaction of singlet oxygen (¹ O₂ ) with vitamin E homologs (α-, β-, γ-, and δ-tocopherols [Toc] and α-, β-, γ-, and δ-tocotrienols [Toc-3]) were measured in an aqueous Triton X-100 (5.0 wt%) micellar solution (pH 7.4). Toc-3 showed k_Q values larger than those of Toc in a micellar solution, although Toc and Toc-3 showed the same k_Q values in a homogeneous solution. Similar measurements were performed for 5 palm oil extracts 1-5 and one soybean extract 6, which contained different concentrations of Toc, Toc-3, and carotenoids. It has been clarified that the ¹ O₂ -quenching rates (k_Q ) (that is, the relative SOAC value) obtained for extracts 3-6 may be explained as the sum of the product ΣkQAO-iAO-i/100 of the rate constant (kQAO-i) and the concentration ([AO-i]/100) of AO-i contained. The UV-vis absorption spectra of Toc and Toc-3 were measured in a micellar solution and chloroform. The results obtained demonstrated that the k_Q values of AO in homogeneous and heterogeneous solutions vary notably depending on (1) polarity (dielectric constant [ε]) of the reaction field between ¹ O₂ and AO, (2) the local concentration of AO, and (3) the mobility of AO in solution. The results suggest that the SOAC method is applicable to the measurement of ¹ O₂ -quenching activity of general food extracts in a heterogeneous micellar solution.

Corina A, Rangel-Zúñiga OA, Jiménez-Lucena R, Alcalá-Díaz JF, Quintana-Navarro G, Yubero-Serrano EM, López-Moreno J, Delgado-Lista J, Tinahones F, Ordovás JM, López-Miranda J, Pérez-Martínez P

J Gerontol A Biol Sci Med Sci. 2018 Aug 27. doi: 10.1093/gerona/gly195. [Epub ahead of print]

Abstract

Leukocyte telomere length (LTL) shortening is a biomarker of cellular aging that can be decelerated by diet. We aimed to investigate the effect of dietary intake of vitamin E on biomarkers of cellular senescence in patients with established cardiovascular disease. To this end, DNA from 1002 participants of the CORDIOPREV study (NCT00924937) was isolated and LTL wa s measured by real-time PCR. Dietary information was collected using a 146-item food frequency questionnaire, and several oxidative stress and damage biomarkers were determined. We found that patients with an inadequate intake of vitamin E according to the European Food Safety Authority, U.S. Food and Nutrition Board, and Spanish dietary recommendation had shorter LTL than those with an adequate intake (p=0.004, p=0.015 and p=0.005, respectively). Moreover, we observed a positive correlation between olive oil, fish consumption and LTL (r²=0.083, p=0.010; r²=0.090, p=0.006, respectively). Subjects who consumed more than 30 mL olive oil/day had longer LTL than subjects with lower consumption (p=0.013). Furthermore, we observed higher glutathione peroxidase activity in subjects consuming less vitamin E (p=0.031). Our findings support the importance of an adequate consumption of the antioxidant vitamin E, and the value of the diet as a modulating tool of the senescence process.Read More

Combination of vitamin E and L-carnitine is superior in protection against Isoproterenol-induced cardiac affection: a histopathological evidence

Huwait EA

Folia Morphol (Warsz). 2018 Aug 14. doi: 10.5603/FM.a2018.0070. [Epub ahead of print]

Abstract

BACKGROUND:

L-carnitine and Vitamin E have antioxidant properties. This study aimed to assess the effectiveness of L-carnitine, Vitamin Eand the combination of them in protection against isoproterenol (ISO)-induced biochemical and histopathological changes in rat heart.

MATERIAL AND METHODS:

Fifty male Wistar rats assigned to 5 groups; control, ISO-treated group (100 mg/kg), ISO+vitamin E-treated group (100 IU/kg), ISO+L-carnitine (100 mg/kg) and ISO+vitamin E+L-carnitine treated group. At the end of the experiment, serum cardiac enzyme as well as the cardiac level Malondialdehyde (MDA), antioxidant enzymes and inflammatory cytokines IL-6, TNF-alpha were assessed. Histopathological changes in the left ventricle wall was assessed using the light and electron microscopy.

RESULTS:

Treating rats with vitamin E and L-carnitine could alleviate ISO-induced changes as it significantly reduced the serum level cardiac enzymes, MDA and IL-6, TNF-alpha and improved the antioxidants enzymes (SOD, GSPxase and GSRase). Histopathological, they improved cardiac fibers atrophy, hemorrhages between cardiac fibers, lost striations, and disturbed sarcomere structure. The combined effect of vitamin E and L-carnitine was more superior compared to the other groups.

CONCLUSION:

Combined administration of vitamin E, L-carnitine ameliorated the biochemical and histopathological cardiac affection induced by ISO. The effect seemed to be mediated through the antioxidant and anti-inflammatory effect of vitamin E, L-carnitine. Administration of these two element is recommended for patient at risk for myocardial infarction.

Meydani SN, Lewis ED, Wu D

Adv Nutr. 2018 Aug 11. doi: 10.1093/advances/nmy035. [Epub ahead of print]

Abstract

Current vitamin E requirements are uniformly applied across the population for those >14 y of age. However, aging is associated with alterations in cellular and physiologic functions, which are affected by vitamin E. Therefore, it is questionable whether vitamin E requirements can be uniformly applied to all adult age categories. With aging, there is dysregulation of the immune system in which there are decreased cell-mediated and pathogen defense responses coupled with an overactive, prolonged inflammatory state. Both animal and human studies in the aged suggest that intake above currently recommended levels of vitamin E may improve immune and inflammatory responses and be associated with a reduced risk of infectious disease. We review the evidence that was considered in establishing the current requirements for vitamin E and highlight data that should be considered in determining the vitamin E requirements in older adults, particularly focusing on the evidence suggesting a benefit of increased vitamin E intake on immune function and inflammatory processes and resistance to infection. The main objective of this Perspective is to initiate the discussion of whether the current Dietary Reference Intake for vitamin E should be increased for the older population. We make this suggestion on the basis of mechanistic studies showing biological plausibility, correction of a major cellular dysfunction in older adults, and strong evidence from several animal and a few human studies indicating a reduction in risk and morbidity from infections.

Montagnani Marelli M, Marzagalli M, Fontana F, Raimondi M, Moretti RM, Limonta P

J Cell Physiol. 2018 Aug 1. doi: 10.1002/jcp.27075. [Epub ahead of print]

Abstract

Vitamin E is composed of two groups of compounds: α-, β-, γ-, and δ-tocopherols (TPs), and the corresponding unsaturated tocotrienols(TTs). TTs are found in natural sources such as red palm oil, annatto seeds, and rice bran. In the last decades, TTs (specifically, γ-TT and δ-TT) have gained interest due to their health benefits in chronic diseases, based on their antioxidant, neuroprotective, cholesterol-lowering, anti-inflammatory activities. Several in vitro and in vivo studies pointed out that TTs also exert a significant antitumor activity in a wide range of cancer cells. Specifically, TTs were shown to exert antiproliferative/proapoptotic effects and to reduce the metastatic or angiogenic properties of different cancer cells; moreover, these compounds were reported to specifically target the subpopulation of cancer stem cells, known to be deeply involved in the development of resistance to standard therapies. Interestingly, recent studies pointed out that TTs exert a synergistic antitumor effect on cancer cells when given in combination with either standard antitumor agents (i.e., chemotherapeutics, statins, “targeted” therapies) or natural compounds with anticancer activity (i.e., sesamin, epigallocatechin gallate (EGCG), resveratrol, ferulic acid). Based on these observations, different TT synthetic derivatives and formulations were recently developed and demonstrated to improve TT water solubility and to reduce TT metabolism in cancer cells, thus increasing their biological activity. These promising results, together with the safety of TT administration in healthy subjects, suggest that these compounds might represent a new chemopreventive or anticancer treatment (i.e., in combination with standard therapies) strategy. Clinical trials aimed at confirming this antitumor activity of TTs are needed.

Kumar A, Sharma R, Rana D, Sharma N

Endocr Metab Immune Disord Drug Targets. 2018 Aug 1. doi: 10.2174/1871530318666180801144822. [Epub ahead of print]

Abstract

BACKGROUND AND OBJECTIVE:

α-Tocopherol is the active form of vitamin E which have various biological functions. However, the exact molecular mechanism of its action is not fully understood. Thus, the main objective of the current study is to determine the contribution of α-tocopherol in counteraction of the apoptogenic signaling pathways induced by deltamethrin in murine thymocytes and splenocytes.

METHODS AND RESULTS:

Deltamethrin (25 µM) induces apoptosis at 18 h through activation of reactive oxygen species, caspases and depletion of glutathione in thymocytes and splenocytes. MTT assay results have shown that α-tocopherol (10 and 50 µg/ml) when added along with Deltamethrin (25µM), increases the viability of thymocytes and splenocytes in a concentration-dependent manner. The α-tocopherol treatment reduces the early markers of cell death (ROS and caspase3 activation) significantly. Further, the depleted GSH by deltamethrin, has been also restored by α-tocopherol. At 18 h, α-tocopherol (50 µg/ml) significantly reduced the Deltamethrin induced cell death. In additional, phenotyping and cytokines assay have demonstrated that alpha-tocopherol significantly ameliorated the altered immune functions.

CONCLUSION:

These findings indicate that α-tocopherol shows immunoprotective effects in Deltamethrin induced splenic and thymic apoptosis by inhibiting oxidative stress and caspase-dependent apoptogenic pathways.

Dong R, Yang Q, Zhang Y, Li J, Zhang L, Zhao H

Wei Sheng Yan Jiu. 2018 Jul;47(4):648-654.

Abstract

OBJECTIVE:

To systematically evaluate the levels of vitamin C, vitamin E and β-carotene in the plasma of Alzheimer’s disease( AD) patients.

METHODS:

In this study, literature of the levels of vitamin C, vitamin E and β-carotene in the plasma of AD patients were collected by retrieving the database of Pub Med, Science Direct, CNKI and Wan Fang( from they were built to July 2017).

RESULTS:

Meta-analysis result showed that, compared with the control group, the level of vitamin E in the plasma of AD patients declined significantly( SMD =-1. 49 μmol/L, 95% CI-2. 08–0. 89 μmol/L, P <0. 001). However, no differences were determined in the levels of the plasma vitamin C and β-carotene between the two groups( vitamin C: SMD =-1. 43 μmol/L, 95% CI-3. 05-0. 19 μmol/L, P = 0. 083; β-carotene: SMD =-0. 61 μmol/L, 95% CI-1. 40-0. 18 μmol/L, P = 0. 131).

CONCLUSION:

Increasing vitamin E level in the plasma through vitamin E riched diet may be useful to prevent AD. However it is not yet believed the benefical role on AD to increase vitamin C and β-carotene.

Najafpour A, Azizizadeh H

Bull Emerg Trauma. 2018 Jul;6(3):207-216. doi: 10.29252/beat-060304.

Abstract

OBJECTIVE:

To investigate effects of intraperitoneally administration of α-tocopherol loaded nanoparticles (TNP) on ischemia-reperfusion injury in ovaries.

METHODS:

Thirty-five healthy female Wistar rats ~250g were randomized into seven experimental groups (n = 5): Group SHAM: The rats underwent only laparotomy. Group Ischemia: A 3- hour ischemia only. Group I/R: A 3-hour ischemia and a 3-hour reperfusion. Group I/T: A 3-hour ischemia only and 100 mg/kg intraperitoneal administration (IP) of α-tocopherol 2.5 hours after induction of ischemia. Group I/R/T: A 3-hour ischemia, a 3-hour reperfusion and 100 mg/kg IP of α-tocopherol 2.5 hours after induction of ischemia. Group I/TNP: A 3-hour ischemia only and 1 mg/kg IP of TNP 2.5 hours after induction of ischemia. Group I/R/TNP: A 3-hour ischemia, a 3-hour reperfusion and 1 mg/kg IP of TNP 2.5 hours after induction of ischemia.

RESULTS:

Animals treated with αTNP showed significantly ameliorated development of ischemia and reperfusion tissue injury compared to those of other groups (p=0.001). The significant higher values of SOD, tGSH, GPO, GSHRd and GST were observed in I/R/NC animals compared to those of other groups (p=0.001). Damage indicators (NOS, MDA, MPO and DNA damage level) were significantly lower in I/R/NC animal compared to those of other groups (p=0.001).

CONCLUSION:

Intraperitoneal administration of TNP could be helpful in minimizing ischemia-reperfusion injury in ovarian tissue exposed to ischemia.

Sun Y, Zhang J, Song W, Shan A

Environ Sci Pollut Res Int. 2018 Jul 12. doi: 10.1007/s11356-018-2666-y. [Epub ahead of print]

Abstract

Phoxim is an organic phosphorus pesticide that remains easily in the environment, such as human food and animal feed. The objective of this study was to explore the effect of vitamin E on phoxim-induced oxidative stress in the intestinal tissues of Sprague-Dawley (SD) rats. Forty-eight Sprague-Dawley rats were randomly assigned to a control group and three treatment groups: treatment group 1 (phoxim: 20 mg/kg·BW), treatment group 2 (phoxim: 180 mg/kg·BW), and treatment 3 (vitamin E + phoxim: 200 mg/kg·BW + 180 mg/kg·BW). Phoxim was given by gavage administration once a day for 28 days. The results showed that phoxim significantly reduced jejunum villus height in rats (P < 0.05), and decreased the mRNA expression of junction protein genes of rats, including Occlidin and Claudin-4 (P < 0.05). Phoxim reduced GSH content and T-AOC level in the intestinal mucosa (P < 0.05). The mRNA expression levels of oxidative stress-related genes (Nrf2 and GPx2) were decreased. The mRNA expression of SOD was significantly increased. In addition, phoxim increased the level of interleukin-6 (IL-6) in jejunum mucosa and significantly reduced the level of IL-8 in ileum mucosas, while significantly increased TNF-α secretion. The mRNA expression levels of IL-1β, IL-6, and IL-8 were significantly decreased, and mRNA expression of TNF-α was significantly increased (P < 0.05). Phoxim also increased the DNA expression of total cecal bacteria and Escherichia coli, inhibited the DNA expression of Lactobacillus and destroyed the intestinal barrier. Two hundred milligrams per kilogram BW vitamin E reduced the effect of phoxim on intestinal structure, alleviated the oxidative stress in intestinal tissue, and decreased the level of TNF-α. The mRNA expressions of antioxidative stress genes (SOD and GPx2) were significantly increased. The DNA expression level of Lactobacillus was significantly increased. In conclusion, vitamin E helped reduce the toxicity of organophosphate pesticides, such as phoxim on rat intestinal tissue.

Jaafar F, Abdullah A, Makpol S

Sci Rep. 2018 Jul 11;8(1):10471. doi: 10.1038/s41598-018-28708-z.

Abstract

Tocotrienol-rich fraction (TRF) is palm vitamin E that consists of tocopherol and tocotrienol. TRF is involved in important cellular regulation including delaying cellular senescence. A key regulator of cellular senescence, Sirtuin 1 (SIRT1) is involved in lipid metabolism. Thus, SIRT1 may regulate vitamin E transportation and bioavailability at cellular level. This study aimed to determine the role of SIRT1 on cellular uptake and bioavailability of TRF in human diploid fibroblasts (HDFs). SIRT1 gene in young HDFs was silenced by small interference RNA (siRNA) while SIRT1 activity was inhibited by sirtinol. TRF treatment was given for 24 h before or after SIRT1 inhibition. Cellular concentration of TRF isomers was determined according to the time points of before and after TRF treatment at 0, 24, 48, 72 and 96 h. Our results showed that all tocotrienol isomers were significantly taken up by HDFs after 24 h of TRF treatment and decreased 24 h after TRF treatment was terminated but remained in the cell up to 72 h. The uptake of α-tocopherol, α-tocotrienol and β-tocotrienol was significantly higher in senescent cells as compared to young HDFs indicating higher requirement for vitamin E in senescent cells. Inhibition of SIRT1 gene increased the uptake of all tocotrienol isomers but not α-tocopherol. However, SIRT1 inhibition at protein level decreased tocotrienol concentration. In conclusion, SIRT1 may regulate the cellular uptake and bioavailability of tocotrienol isomers in human diploid fibroblast cells while a similar regulation was not shown for α-tocopherol.