Blog Archives

Tocotrienol Rich Palm Oil Extract Is More Effective Than Pure Tocotrienols at Improving Endothelium-Dependent Relaxation in the Presence of Oxidative Stress.

Ali SF, Woodman OL

Oxid Med Cell Longev. 2015;2015:150829

Abstract

Oxidative endothelial dysfunction is a critical initiator of vascular disease. Vitamin E is an effective antioxidant but attempts to use it to treat vascular disorders have been disappointing. This study investigated whether tocotrienols, the less abundant components of vitamin E compared to tocopherols, might be more effective at preserving endothelial function. Superoxide generated by hypoxanthine/xanthine oxidase or rat aorta was measured using lucigenin-enhanced chemiluminescence. The effect of α-tocopherol, α-, δ-, and γ-tocotrienols and a tocotrienol rich palm oil extract (tocomin) on levels of superoxide was assessed. Endothelial function in rat aorta was assessed in the presence of the auto-oxidant pyrogallol. Whilst all of the compounds displayed antioxidant activity, the tocotrienols were more effective when superoxide was produced by hypoxanthine/xanthine oxidase whereas tocomin and α-tocopherol were more effective in the isolated aorta. Tocomin and α-tocopherol restored endothelial function in the presence of oxidant stress but α-, δ-, and γ-tocotrienols were ineffective. The protective effect of tocomin was replicated when the tocotrienols were present with, but not without, α-tocopherol. Tocotrienol rich tocomin is more effective than α-tocopherol at reducing oxidative stress and restoring endothelium-dependent relaxation in rat aortae and although α-, δ-, and γ-tocotrienols effectively scavenged superoxide, they did not improve endothelial function.

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Muscadine grape seed oil as a novel source of tocotrienols to reduce adipogenesis and adipocyte inflammation.

Zhao L1, Yagiz Y, Xu C, Lu J, Chung S, Marshall MR.

Food Funct. 2015 Jun 15.

Abstract

Tocotrienols are unsaturated forms of vitamin E previously shown to reduce adipogenesis and adipose inflammation. In this study, muscadine grape seed oil (MGSO) was identified as a novel source of tocotrienols containing significant amounts of α- and γ-tocotrienol (T3) with minor seasonal changes. The aim of this study was to assess the anti-adipogenic and anti-inflammatory potential of MGSO by using primary human adipose-derived stem cells (hASCs). Differentiating hASCs were treated with MGSO and compared with rice bran and olive oil. Accumulation of triglyceride was significantly lower in MGSO-treated hASCs than rice bran and olive oils. A tocotrienol rich fraction (TRF) from MGSO was prepared by solid phase extraction and eluted with 15% 1,4-dioxane in hexane. The MGSO-derived TRF treatment significantly reduced mRNA and protein expression that are crucial to adipogenesis (e.g., PPARγ and aP2) in hASCs. Furthermore, TRF from MGSO markedly reduced LPS-induced proinflammatory gene expression in human adipocytes and cytokine secretion to the medium (IL-6 and IL-8). Collectively, our work suggests that MGSO is a stable and reliable natural source of T3 and MGSO may constitute a new dietary strategy to attenuate obesity and its associated adipose inflammation.

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γ-Tocotrienol and 6-Gingerol in Combination Synergistically Induce Cytotoxicity and Apoptosis in HT-29 and SW837 Human Colorectal Cancer Cells.

Yusof KM, Makpol S, Jamal R, Harun R, Mokhtar N, Ngah WZ.

Molecules. 2015 Jun 3;20(6):10280-97

Abstract

Numerous bioactive compounds have cytotoxic properties towards cancer cells. However, most studies have used single compounds when bioactives may target different pathways and exert greater cytotoxic effects when used in combination. Therefore, the objective of this study was to determine the anti-proliferative effect of γ-tocotrienol (γ-T3) and 6-gingerol (6G) in combination by evaluating apoptosis and active caspase-3 in HT-29 and SW837 colorectal cancer cells. MTS assays were performed to determine the anti-proliferative and cytotoxicity effect of γ-T3 (0-150 µg/mL) and 6G (0-300 µg/mL) on the cells. The half maximal inhibitory concentration (IC50) value of 6G+ γ-T3 for HT-29 was 105 + 67 µg/mL and for SW837 it was 70 + 20 µg/mL. Apoptosis, active caspase-3 and annexin V FITC assays were performed after 24 h of treatment using flow cytometry. These bioactives in combination showed synergistic effect on HT-29 (CI: 0.89 ± 0.02,) and SW837 (CI: 0.79 ± 0.10) apoptosis was increased by 21.2% in HT-29 and 55.4% in SW837 (p < 0.05) after 24 h treatment, while normal hepatic WRL-68 cells were unaffected. Increased apoptosis by the combined treatments was also observed morphologically, with effects like cell shrinkage and pyknosis. In conclusion, although further studies need to be done, γ-T3 and 6G when used in combination act synergistically increasing cytotoxicity and apoptosis in cancer cells.

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Vitamin E Isoform γ-Tocotrienol Downregulates House Dust Mite-Induced Asthma.

Peh HY, Ho WE, Cheng C, Chan TK, Seow AC, Lim AY, Fong CW, Seng KY, Ong CN, Wong WS.

J Immunol. 2015 Jun 3.

Abstract

Inflammation and oxidative damage contribute to the pathogenesis of asthma. Although corticosteroid is the first-line treatment for asthma, a subset of patients is steroid resistant, and chronic steroid use causes side effects. Because vitamin E isoform γ-tocotrienol possesses both antioxidative and anti-inflammatory properties, we sought to determine protective effects of γ-tocotrienol in a house dust mite (HDM) experimental asthma model. BALB/c mice were sensitized and challenged with HDM. Bronchoalveolar lavage (BAL) fluid was assessed for total and differential cell counts, oxidative damage biomarkers, and cytokine levels. Lungs were examined for cell infiltration and mucus hypersecretion, as well as the expression of antioxidants and proinflammatory biomarkers. Sera were assayed for IgE and γ-tocotrienol levels. Airway hyperresponsiveness in response to methacholine was measured. γ-Tocotrienol displayed better free radical-neutralizing activity in vitro and inhibition of BAL fluid total, eosinophil, and neutrophil counts in HDM mouse asthma in vivo, as compared with other vitamin E isoforms, including α-tocopherol. Besides, γ-tocotrienol abated HDM-induced elevation of BAL fluid cytokine and chemokine levels, total reactive oxygen species and oxidative damage biomarker levels, and of serum IgE levels, but it promoted lung-endogenous antioxidant activities. Mechanistically, γ-tocotrienol was found to block nuclear NF-κB level and enhance nuclear Nrf2 levels in lung lysates to greater extents than did α-tocopherol and prednisolone. More importantly, γ-tocotrienol markedly suppressed methacholine-induced airway hyperresponsiveness in experimental asthma. To our knowledge, we have shown for the first time the protective actions of vitamin E isoform γ-tocotrienol in allergic asthma.

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Vitamin E γ-Tocotrienol Inhibits Cytokine-Stimulated NF-κB Activation by Induction of Anti-Inflammatory A20 via Stress Adaptive Response Due to Modulation of Sphingolipids.

Wang Y, Park NY, Jang Y, Ma A, Jiang Q.

J Immunol. 2015 Jul 1;195(1):126-33.

Abstract

NF-κB plays a central role in pathogenesis of inflammation and cancer. Many phytochemicals, including γ-tocotrienol (γTE), a natural form of vitamin E, have been shown to inhibit NF-κB activation, but the underlying mechanism has not been identified. In this study, we show that γTE inhibited cytokine-triggered activation of NF-κB and its upstream regulator TGF-β-activated kinase-1 in murine RAW 264.7 macrophages and primary bone marrow-derived macrophages. In these cells, γTE induced upregulation of A20, an inhibitor of NF-κB. Knockout of A20 partially diminished γTE’s anti-NF-κB effect, but γTE increased another NF-κB inhibitor, Cezanne, in A20(-/-) cells. In search of the reason for A20 upregulation, we found that γTE treatment increased phosphorylation of translation initiation factor 2, IκBα, and JNK, indicating induction of endoplasmic reticulum stress. Liquid chromatography-tandem mass spectrometry analyses revealed that γTE modulated sphingolipids, including enhancement of intracellular dihydroceramides, sphingoid bases in de novo synthesis of the sphingolipid pathway. Chemical inhibition of de novo sphingolipid synthesis partially reversed γTE’s induction of A20 and the anti-NF-κB effect. The importance of dihydroceramide increase is further supported by the observation that C8-dihydroceramide mimicked γTE in upregulating A20, enhancing endoplasmic reticulum stress, and attenuating TNF-triggered NF-κB activation. Our study identifies a novel anti-NF-κB mechanism where A20 is induced by stress-induced adaptive response as a result of modulation of sphingolipids, and it demonstrates an immunomodulatory role of dihydrocermides.

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EGR-1/Bax pathway plays a role in vitamin E δ-tocotrienol-induced apoptosis in pancreatic cancer cells.

Wang C, Husain K, Zhang A, Centeno BA, Chen DT, Tong Z, Sebti SM, Malafa MP.

J Nutr Biochem. 2015 Aug;26(8):797-807.

Abstract

The anticancer activity of δ-tocotrienol, a bioactive vitamin E present in whole grain cereals, annatto beans and palm fruit, is strongly dependent on its effect on the induction of apoptosis. δ-Tocotrienol-induced apoptosis is associated with consistent induction in the expression of the proapoptotic protein Bcl-2-associated X protein (Bax). The molecular mechanism by which δ-tocotrienol regulates Bax expression is unknown. We carried out a DNA microarray study that identified δ-tocotrienol induction of the zinc finger transcription factor EGR-1 in pancreatic cancer cells. Here, we provide evidence linking δ-tocotrienol-induced apoptosis in pancreatic cancer cells to EGR-1 regulation of Bax expression. Forced expression of EGR-1 induces Bax expression and apoptosis in pancreatic cancer cells. In contrast, knockdown of δ-tocotrienol-induced EGR-1 by small interfering RNA attenuated δ-tocotrienol-induced Bax expression and reduced δ-tocotrienol-induced apoptosis. Further analyses showed that de novo protein synthesis was not required for δ-tocotrienol-induced EGR-1 expression, suggesting a direct effect of δ-tocotrienol on EGR-1 expression. Furthermore, a chromatin immunoprecipitation assay demonstrated that EGR-1 binds to the Bax gene promoter. Finally, δ-tocotrienol treatment induced Bax expression and activated EGR-1 in the pancreatic neoplastic cells of the PDX-Cre Kras genetically engineered model of pancreatic cancer. Our study provides the first evidence for EGR-1 as a direct target of vitamin E δ-tocotrienol, suggesting that EGR-1 may act as a proapoptotic factor in pancreatic cancer cells via induction of Bax.

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δ-Tocotrienol treatment is more effective against hypoxic tumor cells than normoxic cells: potential implications for cancer therapy.

Shibata A, Nakagawa K, Tsuduki T, Miyazawa T.

J Nutr Biochem. 2015 Aug;26(8):832-40.

Abstract

Tocotrienols, unsaturated forms of vitamin E, inhibit the proliferation of a variety of cancer cells and suppress angiogenesis. However, the mechanisms underlying those effects on cancer cell growth remain unclear especially under hypoxic conditions. In this study, we demonstrated that δ-tocotrienol (δ-T3) could be used as a novel anticancer agent against human colorectal adenocarcinoma (DLD-1) cells under both normoxic and hypoxic conditions. δ-T3 inhibited the growth of DLD-1 cells in a dose-dependent fashion by inducing cell cycle arrest and apoptosis. This effect was more potent under hypoxic than normoxic conditions. The anticancer effect of δ-T3 was achieved by its up-regulation of cyclin-dependent kinase inhibitors (p21 and p27), the activation of caspases and the suppression of phosphorylation of protein kinase B (Akt) at Thr(308) and Ser(473). In in vivo studies, oral administration of rice bran tocotrienol (RBT3, mainly γ-T3) (10 mg/mouse/day) significantly inhibited tumor growth in nude mice. In tumor analyses, RBT3 activated p21, p27, caspase-3 and caspase-9 and decreased Akt phosphorylation. Furthermore, immunostaining revealed that RBT3 decreased the number of cells positive for CD31/platelet endothelial cell adhesion molecule-1 in microvessels in the tumor. Taken together, these data suggest that tocotrienols are potent antitumor agents capable of inducing apoptosis and inhibiting angiogenesis under both hypoxic and normoxic conditions. Tocotrienols could have significant therapeutic potential in the clinical treatment of tumors.

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The Truth About Natural Vitamin E (as opposed to other kinds)

by

We are all afraid of losing our mind, and our memory. It’s scary to forget what you were just saying or where you put your glasses. No one is clear about what causes memory loss or neurodegenerative brain disorders, but we do know that fat-soluble vitamins like vitamin E support brain health.

Some people are actually (and sadly) afraid to take vitamin E because of a misleading study years ago that concluded vitamin E was bad for us. What a disservice that journalist did to spread the news about this famous study (which will go down in history as one of the most awful tricks to play on sick, vulnerable people)!

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Is your lunch consuming too much land? How palm oil stacks up

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Your sandwich may be harming the environment. A 2015 Dietary Guidelines’ scientific report states that the average American diet has a larger environmental impact in terms of greenhouse gas emissions, land use, water use and energy use compared to a healthier, more plant-based diet. When it comes to land use, the answer is clear: Malaysia’s oil palm plantations. This eco-friendly country utilizes the smallest amount of land to meet much of the world’s vegetable oil needs. Less land use equals less deforestation.

What about the rest of the foods you eat? Discover how your typical American lunch stacks up.

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