Stress has been implicated as a risk factor of various major health problems, such as stress-induced gastric mucosal injury. This study was performed to investigate the action of a pure preparation of tocotrienol (T3) concentrate, made up of 90% -tocotrienol and 10% γ-tocotrienol, on gastric injury of rats induced by water-immersion restraint stress (WIRS). Fourteen male Sprague-Dawley rats (200-250 g) were divided into two equal groups: a control group and a treated group. The treatment group received T3 concentrate at 60 mg/kg body weight daily for 28 days. The body weights of rats were recorded daily before the treatment was given. At the end of the treatment period, all rats were subjected to WIRS for 3.5 hours, following which the rats were euthanized. The stomachs were isolated and opened along the greater curvature for the examination of lesions and measurements of gastric malondialdehyde (MDA) and prostaglandin E2 (PGE2) contents. The mean gastric mucosal lesion index in the treated rats was significantly lower than that in the control rats. This suggests that the T3 concentrate has the ability to confer protection to the gastric mucosa against gastric injury induced by acute stress. No significant difference was observed for changes in body weight before and after the treatment. The gastric PGE2 content in both groups was comparable. However, the gastric MDA content was significantly higher in the treated group compared to the control group, indicating that the T3 supplementation was not able to reduce the lipid peroxidation process. This study concludes that the T3 concentrate has the ability to protect the gastric mucosa from stress-induced injury by a non-antioxidant mechanism.
Inflammation
Studies Targeting α-Glucosidase Inhibition, Antiangiogenic Effects, and Lipid Modification Regulation: Background, Evaluation, and Challenges in the Development of Food Ingredients for Therapeutic Purposes
Nakagawa K
Biosci Biotechnol Biochem. 2013 May 7. [Epub ahead of print]
Since the discovery of α-glucosidase inhibitors and their inhibitory effects on the digestion of carbohydrates, promising results have been obtained as to the antidiabetic effects of this family of compounds. Antiangiogenic compounds have been identified that suppress tumor growth via a unique mechanism, confirming that such compounds can act as clinically applicable anticancer agents. Lipid peroxidation and lipid glycation have been suggested to play roles in food deterioration and in the pathophysiology of human diseases such as atherogenesis and diabetes, and antioxidative and antiglycative compounds can potentially be used in the prevention of food deterioration as well as to treat disease. On this basis, this review describes studies of α-glucosidase inhibition by mulberry 1-deoxynojirimycin, antiangiogenic effects of rice bran tocotrienol, and membrane lipid peroxidation/glycation and its inhibitors. These studies are ongoing in our work, with an emphasis on analytical techniques.
Supplementation with tocotrienol-rich fraction alters the plasma levels of Apolipoprotein A-I precursor, Apolipoprotein E precursor, and C-reactive protein precursor from young and old individuals
Heng, E. C., Karsani, S. A., Abdul Rahman, M., Abdul Hamid, N. A., Hamid, Z., Wan Ngah, W. Z.
2013
Objective: Tocotrienol possess beneficial effects not exhibited by tocopherol. In vitro studies using animal models have suggested that these effects are caused via modulation of gene and protein expression. However, human supplementation studies using tocotrienol-rich isomers are limited. This study aims to identify plasma proteins that changed in expression following tocotrienol-rich fraction (TRF) supplementation within two different age groups.
METHODS: Subjects were divided into two age groups-32 +/- 2 (young) and 52 +/- 2 (old) years old. Four subjects from each group were assigned with TRF (78 % tocotrienol and 22 % tocopherol, 150 mg/day) or placebo capsules for 6 months. Fasting plasma were obtained at 0, 3, and 6 months. Plasma tocopherol and tocotrienol levels were determined. Plasma proteome was resolved by 2DE, and differentially expressed proteins identified by MS. The expressions of three proteins were validated by Western blotting.
RESULTS: Six months of TRF supplementation significantly increased plasma levels of tocopherols and tocotrienols. Proteins identified as being differentially expressed were related to cholesterol homeostasis, acute-phase response, protease inhibitor, and immune response. The expressions of Apolipoprotein A-I precursor, Apolipoprotein E precursor, and C-reactive protein precursor were validated. The old groups showed more proteins changing in expression.
CONCLUSIONS: TRF appears to not only affect plasma levels of tocopherols and tocotrienols, but also the levels of plasma proteins. The identity of these proteins may provide insights into how TRF exerts its beneficial effects. They may also be potentially developed into biomarkers for the study of the effects and effectiveness of TRF supplementation.
Gamma-tocotrienol enhances the chemosensitivity of human oral cancer cells to docetaxel through the downregulation of the expression of NF-kappaB-regulated anti-apoptotic gene products
Kani K, Momota Y, Harada m, et al
Int J Oncol. 2013 Jan;42(1):75-82.
Taxanes, including docetaxel, are widely used for the treatment of squamous cell carcinoma of the head and neck. However, the gastrointestinal toxicity of docetaxel has limited its high-dose clinical use. In this study, we examined the synergistic anticancer effects of combined low-dose docetaxel and gamma-tocotrienol treatment on human oral cancer (B88) cells. We treated B88 cells with docetaxel and gamma-tocotrienol at concentrations of 0.5 nM and 50 microM, respectively. When cells were treated with either agent alone at a low dose, no significant cytotoxic effect was observed. However, the simultaneous treatment of cells with both agents almost completely suppressed cell growth. Whereas docetaxel stimulated the expression of nuclear factor-kappaB (NF-kappaB) p65 protein in B88 cells, gamma-tocotrienol slightly inhibited the expression of constitutive nuclear p65 protein. Of note, the combined treatment with both agents inhibited docetaxel-induced nuclear p65 protein expression. Electrophoretic mobility shift assay (EMSA) revealed that the simultaneous treatment with these agents suppressed the NF-kappaB DNA binding activity in B88 cells. In addition, gamma-tocotrienol downregulated the docetaxel-induced expression of NF-kappaB-regulated gene products associated with the inhibition of apoptosis. Furthermore, the activation of initiator caspases, caspases-8 and -9, and the effector caspase, caspase-3, was detected following treatment with both agents. Finally, apoptosis was also clearly observed as demonstrated by the cleavage of poly(ADP-ribose) polymerase (PARP) and nuclear fragmentation through the activation of caspase-3 by combined treatment with docetaxel and gamma-tocotrienol. These findings suggest that the combination treatment with these agents may provide enhanced therapeutic response in oral cancer patients, while avoiding the toxicity associated with high-dose beta-tubulin stabilization monotherapy.
Comparative effects of tocotrienol-rich fraction, α-tocopherol and α-tocopheryl acetate on inflammatory mediators and nuclear factor kappa B expression in mouse peritoneal macrophages
Ng LT, Ko HJ.
Food Chem. 2012 Sep 15;134(2):920-5
The effects of tocotrienol-rich fraction (TRF), α-tocopherol (T) and α-tocopheryl acetate (TA) on lipopolysaccharide (LPS)-induced inflammatory responses in mouse peritoneal macrophages were examined. Results showed that at 5-30μg/ml, all test compounds plus 1μg/ml LPS exhibited no cytotoxic effects on macrophage cells. Compared with T and TA, TRF showed the strongest anti-inflammatory activity as demonstrated by its potency in inhibiting the LPS-induced nitric oxide (NO), prostaglandin E(2) (PGE(2)), and proinflammatory cytokine (TNF-α, IFN-γ, IL-1β and IL-6) production. At 10μg/ml, it significantly blocked the LPS induction of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression, but has no effect on cyclooxygenase-1 (COX-1). Furthermore, TRF also showed a greater inhibition on the nuclear factor kappa B (NF-κB) expression than T and TA. These results suggest that TRF could be a better agent than T and TA for use in the prevention of chronic inflammatory diseases.
Inhibition of nitric oxide and inflammatory cytokines in LPS-stimulated murine macrophages by resveratrol, a potent proteasome inhibitor
Qureshi AA, Guan XQ, Reis JC, Papasian CJ, Jabre S, Morrison DC, Qureshi N.
Lipids Health Dis. 2012 Jul 10;11:76.
Background: Altered immune function during ageing results in increased production of nitric oxide (NO) and other inflammatory mediators. Recently, we have reported that NO production was inhibited by naturally-occurring proteasome inhibitors (quercetin, δ-tocotrienol, and riboflavin) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells, and thioglycolate-elicited peritoneal macrophages from C57BL/6 mice. In a continuous effort to find more potent, non-toxic, commercially available, naturally-occurring proteasome inhibitors that suppress inflammation, the present study was carried out to describe the inhibition of NF-κB activation and NO, TNF-α, IL-6, IL-1β, and iNOS expression by trans-resveratrol, trans-pterostilbene, morin hydrate, and nicotinic acid in LPS-induced RAW 264.7 cells and thioglycolate-elicited peritoneal macrophages from C57BL/6 and BALB/c mice.
Results: The present results indicate that resveratrol, pterostilbene, and morin hydrate caused significant inhibition (>70% to 90%; P < 0.02) in the activities of chymotrypsin-like, trypsin-like, and post-acidic (post-glutamase) proteasome sites in RAW 264.7 cells at a dose of only 20 μM. These compounds also inhibited the production of NO by RAW-264.7 cells stimulated with LPS alone (>40%; P < 0.05), or LPS + interferon-γ (IFN-γ; >60%; P < 0.02). Furthermore, resveratrol, pterostilbene, morin hydrate, and quercetin suppressed secretion of TNF-α (>40%; P < 0.05) in LPS-stimulated RAW 264.7 cells, and suppressed NF-κB activation (22% to 45%; P < 0.05) in LPS-stimulated HEK293T cells. These compounds also significantly suppressed LPS-induced expression of TNF-α, IL-1β, IL-6, and iNOS genes in RAW 264.7 cells, and also in thioglycolate-elicited peritoneal macrophages from C57BL/6 and BALB/c mice.
Conclusions: The present results clearly demonstrate that resveratrol and pterostilbene are particularly potent proteasome inhibitors that suppress expression of genes, and production of inflammatory products in LPS-stimulated RAW 264.7 cells, and macrophages from C57BL/6 and BALB/c mice. Resveratrol and pterostilbene which are present in grapes, blueberries, and red wine, have been implicated as contributing factors to the lower incidence of cardiovascular disease in the French population, despite their relatively high dietary fat intake. Consequently, it appears likely that the beneficial nutritional effects of resveratrol and pterostilbene are due at least in part, to their ability to inhibit NF-κB activation by the proteasome, thereby suppressing activation of pro-inflammatory cytokines and iNOS genes, resulting in decreased secretion of TNF-α, IL-1β, IL-6, and NO levels, in response to inflammatory stimuli. This is the first report demonstrating that resveratrol and pterostilbene act as proteasome inhibitors, thus providing a mechanism for their anti-inflammatory effects.
Suppression of Nitric Oxide Production and Cardiovascular Risk Factors in Healthy Seniors and Hypercholesterolemic Subjects by a Combination of Polyphenols and Vitamins
Qureshi AA, Khan DA, Mahjabeen W, Papasian CJ, Qureshi N.
J Clin Exp Cardiolog. 2012 Jun 7;S5:8.
Background: Dysregulated immune function associated with ageing has been implicated in a variety of human diseases. We have demonstrated the anti-inflammatory properties of resveratrol, pterostilbene, morin hydrate, quercetin, δ-tocotrienol, riboflavinin a variety of experimental animal models, and determined that these compounds act by inhibiting proteasome activity.
Aims: To determine whether serum nitric oxide (NO) levels increase with age in humans, and whether the combined cholesterol-lowering and inflammation-reducing properties of resveratrol, pterostilbene, Morin hydrate, quercetin, δ-tocotrienol, riboflavin, and nicotinic acid would reduce cardiovascular risk factors in humans when used as nutritional supplements with, or without, other dietary changes.
Methods: Elderly human subjects were stratified into two groups based on total serum cholesterol levels. Initial total serum cholesterol levels were normal and elevated in Group 1 and 2 subjects, respectively. Baseline serum NO, C-reactive protein (CRP), γ-glutamyltransferase (γ-GT) activity, uric acid, total antioxidant status (TAS), total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides levels were established over a four week period. Group 1 subjects subsequently received nutritional supplementation with one of two different combinations (NS-7 = 25 mg of each, resveratrol, pterostilbene, quercetin, δ-tocotrienol, nicotinic acid, morin hydrate or NS-6 = morin hydrate replaced with quercetin, 50 mg/capsule). Group 2 subjects also received these nutritional supplements (two capsules/d), but an AHA Step-1 diet was also implemented. After these interventions were administered for four weeks, the above parameters were re-measured and changes from baseline levels determined. Nitric acid (NO) levels in children, young adults, and seniors were also compared.
Results: The key results of the current study were: 1) that serum NO levels were significantly increased in seniors compared to both children (~80%) and young adults (~65%); 2) that the intake of two capsules/d of NS-7 or NS-6 for four weeks significantly (P < 0.05) decreased serum NO (39%, 24%), CRP (19%, 21%), uric acid (6%, 12%) levels, and γ-GT activity (8%, 6%), respectively in free-living healthy seniors; 3) that serum NO (36%, 29%), CRP (29%, 20%), uric acid (6%, 9%) γ-GT activity (9%, 18%), total cholesterol (8%, 11%), LDL-cholesterol (10%, 13%), and triglycerides (16%, 23%) levels were significantly (P < 0.02) decreased in hypercholesterolemic subjects restricted to AHA Step-1 diet plus intake of SN-7 or SN-6 (two capsules/d), respectively; 4) that TAS was increased (3%, 9%; P < 0.05) in free-living healthy seniors receiving NS-7 or NS-6 alone, and in hypercholesterolemic subjects plus AHA Step-1 diet (20%, 12%; P < 0.02) with either of the combinations tested.
Conclusion: Serum NO levels are elevated in elderly humans compared to children or young adults. Diet supplementation with combinations of resveratrol, pterostilbene, morin hydrate, quercetin, δ-tocotrienol, riboflavin, and nicotinic acid reduce cardiovascular risk factors in humans when used as nutritional supplements with, or without, other dietary changes.
γ-Tocotrienol attenuates TNF-α-induced changes in secretion and gene expression of MCP-1, IL-6 and adiponectin in 3T3-L1 adipocytes
Matsunaga T, Shoji A, Gu N, Joo E, Li S, Adachi T, Yamazaki H, Yasuda K, Kondoh T, Tsuda K.
Mol Med Report. 2012 Apr;5(4):905-9. Epub 2012 Jan 30.
Tocotrienols, members of the vitamin E family, have been shown to possess anti-inflammatory properties and display activity against a variety of chronic diseases, such as cancer, cardiovascular and neurological diseases. However, whether tocotrienols contribute to the prevention of inflammatory responses in adipose tissue remains to be elucidated. In this study, we examined the effects of γ-tocotrienol, the most commontocotrienol isomer, on tumor necrosis factor-α (TNF-α)-induced inflammatory responses by measuring the expression of the adipokines, monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6) and adiponectin in 3T3-L1 adipocytes. Exposure to TNF-α (10 ng/ml) for 24 h increased MCP-1 and IL-6 secretion, and decreased adiponectin secretion and peroxisome proliferator-activated receptor-γ (PPARγ) mRNA expression. γ-tocotrienoleffectively improved the TNF-α-induced adverse changes in MCP-1, IL-6 and adiponectin secretion, and in MCP-1, IL-6, adiponectin and PPARγ mRNA expression. Furthermore, TNF-α-mediated IκB-α phosphorylation and nuclear factor-κB (NF-κB) activation were significantly suppressed by the γ-tocotrienol treatment. Our results suggest that γ-tocotrienol may improve obesity-related functional abnormalities in adipocytes by attenuating NF-κB activation and the expression of inflammatory adipokines.
Comparative effect of TRF aTP and aTPA on inflammatory mediators and NF-KB expression in mouse peritoneal macrophages
Lean-Teik Ng, Huey-Jiun Ko
Food Chemistry 134 (2012) 920–925 Epub 16 March 2012
The effects of tocotrienol-rich fraction (TRF), a-tocopherol (T) and a-tocopheryl acetate (TA) on lipopolysaccharide (LPS)-induced inflammatory responses in mouse peritoneal macrophages were examined. Results showed that at 5–30 lg/ml, all test compounds plus 1 lg/ml LPS exhibited no cytotoxic effects on macrophage cells. Compared with T and TA, TRF showed the strongest anti-inflammatory activity as demonstrated by its potency in inhibiting the LPS-induced nitric oxide (NO), prostaglandin E2 (PGE2), and proinflammatory cytokine (TNF-a, IFN-c, IL-1b and IL-6) production. At 10 lg/ml, it signifi-
cantly blocked the LPS induction of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression, but has no effect on cyclooxygenase-1 (COX-1). Furthermore, TRF also showed a greater inhibition on the nuclear factor kappa B (NF-jB) expression than T and TA. These results suggest that TRF could be a better agent than T and TA for use in the prevention of chronic inflammatory diseases.
Inhibition of nitric oxide in LPS-stimulated macrophages of young and senescent mice by δ-tocotrienol and quercetin
Qureshi AA, Tan X, Reis JC, Badr MZ, Papasian CJ, Morrison DC, Qureshi N.
Lipids Health Dis. 2011 Dec 20;10:239.
Background: Changes in immune function believed to contribute to a variety of age-related diseases have been associated with increased production of nitric oxide (NO). We have recently reported that proteasome inhibitors (dexamethasone, mevinolin, quercetin, δ-tocotrienol, and riboflavin) can inhibit lipopolysaccharide (LPS)-induced NO production in vitro by RAW 264.7 cells and by thioglycolate-elicited peritoneal macrophages derived from four strains of mice (C57BL/6, BALB/c, LMP7/MECL-1(-/-) and PPAR-α(-/-) knockout mice). The present study was carried out in order to further explore the potential effects of diet supplementation with naturally-occurring inhibitors (δ-tocotrienol and quercetin) on LPS-stimulated production of NO, TNF-α, and other pro-inflammatory cytokines involved in the ageing process. Young (4-week-old) and senescent mice (42-week old) were fed control diet with or without quercetin (100 ppm), δ-tocotrienol (100 ppm), or dexamethasone (10 ppm; included as positive control for suppression of inflammation) for 4 weeks. At the end of feeding period, thioglycolate-elicited peritoneal macrophages were collected, stimulated with LPS, LPS plus interferon-β (IFN-β), or LPS plus interferon-γ (IFN-γ), and inflammatory responses assessed as measured by production of NO and TNF-α, mRNA reduction for TNF-α, and iNOS genes, and microarray analysis.