Displaying publications 1 - 20 of 54 in total

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  1. Fulltext Effect of experimental treatment on GAPDH mRNA expression as a housekeeping gene in human diploid fibroblasts
    Zainuddin A, Chua KH, Abdul Rahim N, Makpol S
    BMC Mol. Biol., 2010;11:59.
    PMID: 20707929 DOI: 10.1186/1471-2199-11-59
    Several genes have been used as housekeeping genes and choosing an appropriate reference gene is important for accurate quantitative RNA expression in real time RT-PCR technique. The expression levels of reference genes should remain constant between the cells of different tissues and under different experimental conditions. The purpose of this study was to determine the effect of different experimental treatments on the expression of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) mRNA so that the reliability of GAPDH as reference gene for quantitative real time RT-PCR in human diploid fibroblasts (HDFs) can be validated. HDFs in 4 different treatment groups viz; young (passage 4), senescent (passage 30), H2O2-induced oxidative stress and gamma-tocotrienol (GTT)-treated groups were harvested for total RNA extraction. Total RNA concentration and purity were determined prior to GAPDH mRNA quantification. Standard curve of GAPDH expression in serial diluted total RNA, melting curve analysis and agarose gel electrophoresis were used to determine the reliability of GAPDH as reference gene.
    Matched MeSH terms: Chromans/pharmacology
  2. γ-Tocotrienol prevents cell cycle arrest in aged human fibroblast cells through p16INK4a pathway
    Zainuddin A, Chua KH, Tan JK, Jaafar F, Makpol S
    J Physiol Biochem, 2017 Feb;73(1):59-65.
    PMID: 27743340 DOI: 10.1007/s13105-016-0524-2
    Human diploid fibroblasts (HDFs) proliferation in culture has been used as a model of aging at the cellular level. Growth arrest is one of the most important mechanisms responsible for replicative senescence. Recent researches have been focusing on the function of vitamin E in modulating cellular signaling and gene expression. Therefore, the aim of this study was to elucidate the effect of palm γ-tocotrienol (vitamin E) in modulating cellular aging through p16INK4a pathway in HDF cells. Primary culture of senescent HDFs was incubated with 70 μM of palm γ-tocotrienol for 24 hours. Silencing of p16INK4a was carried out by siRNA transfection. RNA was extracted from the different treatment groups and gene expression analysis was carried out by real-time reverse transcription polymerase chain reaction. Proteins that were regulated by p16INK4a were determined by western blot technique. The finding of this study showed that p16INK4a mRNA was overexpressed in senescent HDFs, and hypophosphorylated-pRb and cyclin D1 protein expressions were increased (p 
    Matched MeSH terms: Chromans/metabolism*
  3. Plasma vitamin C and tocotrienols changes in response to dietary supplementation among young male adults
    Zahara AM, Lee CC, Fatimah IS, Poh BK, Khairul O, Das S, et al.
    Clin Ter, 2010;161(2):121-4.
    PMID: 20499024
    Intake of the antioxidant vitamins C and E lowers the oxidative stress. The study aimed to determine plasma concentrations of vitamin C and tocotrienols after supplementation of both vitamins in young male adults.
    Matched MeSH terms: Chromans
  4. Fulltext 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 03;20(6):10280-97.
    PMID: 26046324 DOI: 10.3390/molecules200610280
    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.
    Matched MeSH terms: Chromans/pharmacology*
  5. Suppression of colorectal cancer cell growth by combined treatment of 6-gingerol and γ-tocotrienol via alteration of multiple signalling pathways
    Yusof KM, Makpol S, Fen LS, Jamal R, Wan Ngah WZ
    J Nat Med, 2019 Sep;73(4):745-760.
    PMID: 31177355 DOI: 10.1007/s11418-019-01323-6
    Our previous study reported that combined treatment of γ-tocotrienol with 6-gingerol showed promising anticancer effects by synergistically inhibiting proliferation of human colorectal cancer cell lines. This study aimed to identify and elucidate molecular mechanisms involved in the suppression of SW837 colorectal cancer cells modulated by combined treatment of γ-tocotrienol and 6-gingerol. Total RNA from both untreated and treated cells was prepared for transcriptome analysis using RNA sequencing techniques. We performed high-throughput sequencing at approximately 30-60 million coverage on both untreated and 6G + γT3-treated cells. The results showed that cancer-specific differential gene expression occurred and functional enrichment pathway analysis suggested that more than one pathway was modulated in 6G + γT3-treated cells. Combined treatment with 6G + γT3 augmented its chemotherapeutic effect by interfering with the cell cycle process, downregulating the Wnt signalling pathway and inducing apoptosis mainly through caspase-independent programmed cell death through mitochondrial dysfunction, activation of ER-UPR, disruption of DNA repair mechanisms and inactivation of the cell cycle process through the downregulation of main genes in proliferation such as FOXM1 and its downstream genes. The combined treatment exerted its cytotoxic effect through upregulation of genes in stress response activation and cytostatic effects demonstrated by downregulation of main regulator genes in the cell cycle. Selected genes involved in particular pathways including ATF6, DDIT3, GADD34, FOXM1, CDK1 and p21 displayed concordant patterns of gene expression between RNA sequencing and RT-qPCR. This study provides new insights into combined treatment with bioactive compounds not only in terms of its pleiotropic effects that enhance multiple pathways but also specific target genes that could be exploited for therapeutic purposes, especially in suppressing cancer cell growth.
    Matched MeSH terms: Chromans
  6. Influence of lipolysis and droplet size on tocotrienol absorption from self-emulsifying formulations
    Yap SP, Yuen KH
    Int J Pharm, 2004 Aug 20;281(1-2):67-78.
    PMID: 15288344
    A single dose comparative bioavailability study was conducted to evaluate the bioavailability of tocotrienols from two self-emulsifying formulations, one of which produced an emulsion that readily lipolysed under in vitro condition (SES-A), while the other produced a finer dispersion with negligible lipolysis (SES-B) in comparison with that of a non-self-emulsifying formulation in soya oil. The study was conducted according to a three-way crossover design using six healthy human volunteers. Statistically significant differences were observed between the logarithmic transformed peak plasma concentration (Cmax) and total area under the plasma concentration-time curve (AUC(0-infinity)) values of both SES-A and -B compared to NSES-C indicating that SES-A and -B achieved a higher extent of absorption compared to NSES-C. Moreover, the 90% confidence interval of the AUC(0-infinity) values of both SES-A and -B over those of NSES-C were between 2-3 suggesting an increase in bioavailability of about two-three times compared to NSES-C. Both SES-A and -B also achieved a faster onset of absorption. However, both SES-A and -B had comparable bioavailability, despite the fact that SES-B was able to form emulsions with smaller droplet size. Thus, it appeared that both droplet sizes as well as the rate and extent of lipolysis of the emulsion products formed were important for enhancing the bioavailability of the tocotrienols from the self-emulsifying systems.
    Matched MeSH terms: Chromans/blood
  7. Influence of route of administration on the absorption and disposition of alpha-, gamma- and delta-tocotrienols in rats
    Yap SP, Yuen KH, Lim AB
    J Pharm Pharmacol, 2003 Jan;55(1):53-8.
    PMID: 12625867
    A study was conducted to evaluate the bioavailability of alpha-, gamma- and delta-tocotrienols administered via oral, intravenous, intramuscular and intraperitoneal routes in rats. Three separate experiments, each conducted according to a two-way crossover design, were carried out to compare intravenous and oral, intramuscular and oral, and intraperitoneal and oral administration. Oral absorption of all three tocotrienols was found to be incomplete. Of the three tocotrienols, alpha-tocotrienol had the highest oral bioavailability, at about 27.7+/-9.2%, compared with gamma- and delta-tocotrienols, which had values of 9.1+/-2.4% and 8.5+/-3.5%, respectively. Such biodiscrimination was also observed in their total clearance rates (estimated from the intravenous data). alpha-Tocotrienol showed the lowest clearance rate at about 0.16 L kg(-1) h(-1), whereas that of delta- and gamma-tocotrienols was quite similar, with values of 0.24 and 0.23 L kg(-1) h(-1), respectively. Interestingly, all three tocotrienols were found to be negligibly absorbed when administered intraperitoneally and intramuscularly. Thus, these two routes of administration should be avoided when evaluating the biological activities of the tocotrienols in whole animal experiments.
    Matched MeSH terms: Chromans/administration & dosage*; Chromans/pharmacokinetics*
  8. Pharmacokinetics and bioavailability of alpha-, gamma- and delta-tocotrienols under different food status
    Yap SP, Yuen KH, Wong JW
    J Pharm Pharmacol, 2001 Jan;53(1):67-71.
    PMID: 11206194
    We have investigated the pharmacokinetics and bioavailability of alpha-, gamma- and delta-tocotrienols under fed and fasted conditions in eight healthy volunteers. The volunteers were administered a single oral dose of mixed tocotrienols (300 mg) under fed or fasted conditions. The bioavailability of tocotrienols under the two conditions was compared using the parameters peak plasma concentration (Cmax), time to reach peak plasma concentration (Tmax) and total area under the plasma concentration-time curve (AUC(o-infinity)). A statistically significant difference was observed between the fed and fasted logarithmic transformed values of Cmax (P < 0.01) and AUC(0-infinity) (P < 0.01) for all three tocotrienols. In addition, the 90% confidence intervals for the ratio of the logarithmic transformed AUC(0-infinity) values of alpha-, gamma- and delta-tocotrienols under the fed state over those of the fasted state were found to lie between 2.24-3.40, 2.05-4.09 and 1.59-3.81, respectively, while those of the Cmax were between 2.28-4.39, 2.31-5.87 and 1.52-4.05, respectively. However, no statistically significant difference was observed between the fed and fasted Tmax values of the three homologues. The mean apparent elimination half-life (t(1/2)) of alpha-, gamma- and delta-tocotrienols was estimated to be 4.4, 4.3 and 2.3 h, respectively, being between 4.5- to 8.7-fold shorter than that reported for alpha-tocopherol. No statistically significant difference was observed between the fed and fasted t(1/2) values. The mean apparent volume of distribution (Vd/f) values under the fed state were significantly smaller than those of the fasted state, which could be attributed to increased absorption of the tocotrienols in the fed state.
    Matched MeSH terms: Chromans/pharmacokinetics*
  9. δ- and γ-tocotrienols induce classical ultrastructural apoptotic changes in human T lymphoblastic leukemic cells
    Wong RS, Radhakrishnan AK, Ibrahim TA, Cheong SK
    Microsc Microanal, 2012 Jun;18(3):462-9.
    PMID: 22640960 DOI: 10.1017/S1431927612000177
    Tocotrienols are isomers of the vitamin E family, which have been reported to exert cytotoxic effects in various cancer cells. Although there have been some reports on the effects of tocotrienols in leukemic cells, ultrastructural evidence of tocotrienol-induced apoptotic cell death in leukemic cells is lacking. The present study investigated the effects of three isomers of tocotrienols (alpha, delta, and gamma) on a human T lymphoblastic leukemic cell line (CEM-SS). Cell viability assays showed that all three isomers had cytotoxic effects (p < 0.05) on CEM-SS cells with delta-tocotrienol being the most potent. Transmission electron microscopy showed that the cytotoxic effects by delta- and gamma-tocotrienols were through the induction of an apoptotic pathway as demonstrated by the classical ultrastructural apoptotic changes characterized by peripheral nuclear chromatin condensation and nuclear fragmentation. These findings were confirmed biochemically by the demonstration of phosphatidylserine externalization via flow cytometry analysis. This is the first study showing classical ultrastructural apoptotic changes induced by delta- and gamma-tocotrienols in human T lymphoblastic leukemic cells.
    Matched MeSH terms: Chromans/toxicity*
  10. Fulltext Impact of Quercetin Encapsulation with Added Phytosterols on Bilayer Membrane and Photothermal-Alteration of Novel Mixed Soy Lecithin-Based Liposome
    Toopkanloo SP, Tan TB, Abas F, Alharthi FA, Nehdi IA, Tan CP
    Nanomaterials (Basel), 2020 Dec 05;10(12).
    PMID: 33291386 DOI: 10.3390/nano10122432
    This study used highly lipophilic agents with an aim to increase the oxidant inhibitory activity and enhance photothermal stability of a novel mixed soy lecithin (ML)-based liposome by changing the composition of formulation within the membrane. Specifically, the development and optimization of the liposome intended for improving Trolox equivalent antioxidant capacity (TEAC) value and %TEAC loss was carried out by incorporating a natural antioxidant, quercetin (QU). In this context, a focus was set on QU encapsulation in ML-based liposomes and the concentration-dependent solubility of QU was investigated and calculated as encapsulation efficiency (EE). To explore the combined effects of the incorporation of plant sterols on the integrity and entrapment capacity of mixed phospholipid vesicles, conjugation of two types of phytosterols (PSs), namely β-sitosterol (βS) and stigmasterol (ST), to mixed membranes at different ratios was also performed. The EE measurement revealed that QU could be efficiently encapsulated in the stable ML-based liposome using 0.15 and 0.1 g/100 mL of βS and ST, respectively. The aforementioned liposome complex exhibited a considerable TEAC (197.23%) and enhanced TEAC loss (30.81%) when exposed to ultraviolet (UV) light (280-320 nm) over a 6 h duration. It appeared that the presence and type of PSs affect the membrane-integration characteristics as well as photodamage transformation of the ML-based liposome. The association of QU with either βS or ST in the formulation was justified by their synergistic effects on the enhancement of the EE of liposomes. Parallel to this, it was demonstrated that synergistic PS effects could be in effect in the maintenance of membrane order of the ML-based liposome. The findings presented in this study provided useful information for the development and production of stable QU-loaded ML-based liposomes for food and nutraceutical applications and could serve as a potential mixed lipids-based delivery system in the disease management using antioxidant therapy.
    Matched MeSH terms: Chromans
  11. Fulltext Comparison of antioxidant properties of pomelo [Citrus Grandis (L) Osbeck] varieties
    Toh, J.J., Khoo, H.E., Azrina, A.
    International Food Research Journal, 2013;20(4):1661-1668.
    MyJurnal
    This study aimed to compare the antioxidant content and antioxidant capacity of pulp and peel of two varieties of pomelo fruit (Tambun White and Tambun Pink). Antioxidants including total phenolic content, total flavonoid content and ascorbic acid content were determined using Folin-Ciocalteu reagent assay, aluminium chloride colorimetric assay and AOAC method, respectively. Antioxidant capacity of pomelo pulp and peel was measured using ferric reducing antioxidant potential and trolox equivalent antioxidant capacity assays. The peels of both pomelo fruits had higher antioxidant content and capacity than their pulps. Moreover, the white variety of pomelo had higher antioxidant content and capacity compared to the pink counterpart. Trolox equivalent antioxidant capacity of the samples was positively high correlated with total phenolic content (r = 0.978) and total flavonoid content (r = 0.959), except for ascorbic acid. Therefore, pomelo peel from white variety possessed higher antioxidant properties and it is potentially rich sources of natural antioxidants.
    Matched MeSH terms: Chromans
  12. Is vitamin E toxic to neuron cells?
    Then SM, Mazlan M, Mat Top G, Wan Ngah WZ
    Cell Mol Neurobiol, 2009 Jun;29(4):485-96.
    PMID: 19172392 DOI: 10.1007/s10571-008-9340-8
    Besides acting as potent free radical scavengers, tocopherols and tocotrienols have been known to have non-antioxidant properties such as the involvement of alpha-tocopherol (alphaT) in PKC pathway and the anti-cancer properties of gamma-tocotrienol (gammaT3). This study aims to elucidate whether protective effects shown by alphaT and gammaT3 in H(2)O(2)-induced neuron cultures have anti-apoptotic or pro-apoptotic tendency toward the initiation of neuronal apoptosis. H(2)O(2) is used to induce apoptosis in primary cerebellar neuron cultures which is attenuated by pretreatment of alphaT or gammaT3 at concentrations < or =10 microM. Similar to our previous work, gammaT3 was found to be neurotoxic at concentrations > or =100 microM, whereas alphaT showed no neurotoxicity. Cellular uptake of gammaT3 was higher than that of alphaT. Treating cells simultaneously with either gammaT3 or alphaT and with then H(2)O(2) led to higher expression of Bax and Bcl-2 than in neurons exposed to H(2)O(2) alone. Analysis of Bcl-2/Bax ratio as 'survival index' showed that both pretreatment of gammaT3 and alphaT followed by H(2)O(2) increase the 'survival index' of Bcl-2/Bax ratio compared to H(2)O(2)-treated cells, while treatment of gammaT3 alone decrease the ratio compared to unchanged Bcl2/Bax ratio of similar treatment with alphaT alone. Similar treatment of gammaT3 decreased p53 expression and activates p38 MAPK phosphorylation, whereas alphaT did not alter its expression compared to H(2)O(2)-treated cells. Treating neurons with only gammaT3 or alphaT increased the expression of Bax, Bcl-2, p53, and p38 MAPK compared to control with gammaT3 exerting stronger expression for proteins involved than alphaT. In conclusion, low doses of gammaT3 and alphaT confer neuroprotection to H(2)O(2)-treated neurons via their antioxidant mechanism but gammaT3 has stronger pro-apoptosis tendency than alphaT by activating molecules involved in the neuronal apoptotic pathway in the absence of H(2)O(2).
    Matched MeSH terms: Chromans/pharmacology
  13. Fulltext Comparison of antioxidant components and antioxidant capacity in different parts of nutmeg (Myristica fragrans)
    Tan, K.P., Khoo, H.E., Azrina, A.
    International Food Research Journal, 2013;20(3):1049-1052.
    MyJurnal
    This study aimed to determine and compare antioxidant components and antioxidant capacity in different parts (skin, pulp, mace and seed) of nutmeg. Freeze dried samples were extracted using 80% methanol, while Folin-Ciocalteu assay was employed to determine total phenolic content, aluminium chloride assay was applied to determine total flavonoid content and ascorbic acid was assessed by titrimetric method. Antioxidant activities were evaluated by ferric reducing antioxidant power and trolox equivalent antioxidant capacity (TEAC) assays. Results revealed that nutmeg seed contained the highest TPC followed by mace, skin and pulp. Similar observation was also found for TFC. The highest ascorbic acid content was found in nutmeg mace, while the lowest was in its pulp. For antioxidant activity, nutmeg seed possessed the highest FRAP and TEAC values, while nutmeg pulp had the lowest as compared to other parts. Phenolic compounds in nutmeg samples have exhibited strong correlation with antioxidant capacity. Therefore, nutmeg is a potential functional food with high antioxidants, especially nutmeg seed. Phenolic compounds in nutmeg samples have exhibited strong correlation with antioxidant capacity. Therefore, nutmeg is a potential functional food with high antioxidants, especially nutmeg seed.
    Matched MeSH terms: Chromans
  14. Inhibitory effects of palm α-, γ- and δ-tocotrienol on lipopolysaccharide-induced nitric oxide production in BV2 microglia
    Tan SW, Ramasamy R, Abdullah M, Vidyadaran S
    Cell Immunol, 2011;271(2):205-9.
    PMID: 21839427 DOI: 10.1016/j.cellimm.2011.07.012
    Anti-inflammatory actions of the vitamin E fragment tocotrienol have not been described for microglia. Here, we screened palm α-, γ- and δ-tocotrienol isoforms and Tocomin® 50% (contains spectrum of tocotrienols and tocopherols) for their ability to limit nitric oxide (NO) production by BV2 microglia. Microglia were treated with varying doses of tocotrienols for 24h and stimulated with 1 μg/ml lipopolysaccharide (LPS). All tocotrienol isoforms reduced NO release by LPS-stimulated microglia, with 50 μM being the most potent tocotrienol dose. Of the isoforms tested, δ-tocotrienol lowered NO levels the most, reducing NO by approximately 50% at 48 h post-LPS treatment (p
    Matched MeSH terms: Chromans/pharmacology
  15. Gamma-tocotrienol acts as a BH3 mimetic to induce apoptosis in neuroblastoma SH-SY5Y cells
    Tan JK, Then SM, Mazlan M, Raja Abdul Rahman RN, Jamal R, Wan Ngah WZ
    J Nutr Biochem, 2016 May;31:28-37.
    PMID: 27133421 DOI: 10.1016/j.jnutbio.2015.12.019
    Bcl-2 family proteins are crucial regulators of apoptosis. Both pro- and antiapoptotic members exist, and overexpression of the latter facilitates evasion of apoptosis in many cancer types. Bcl-2 homology domain 3 (BH3) mimetics are small molecule inhibitors of antiapoptotic Bcl-2 family members, and these inhibitors are promising anticancer agents. In this study, we report that gamma-tocotrienol (γT3), an isomer of vitamin E, can inhibit Bcl-2 to induce apoptosis. We demonstrate that γT3 induces cell death in human neuroblastoma SH-SY5Y cells by depolarising the mitochondrial membrane potential, enabling release of cytochrome c to the cytosol and increasing the activities of caspases-9 and -3. Treatment of cells with inhibitors of Bax or caspase-9 attenuated the cell death induced by γT3. Simulated docking analysis suggested that γT3 binds at the hydrophobic groove of Bcl-2, while a binding assay showed that γT3 competed with a fluorescent probe to bind at the hydrophobic groove. Our data suggest that γT3 mimics the action of BH3-only protein by binding to the hydrophobic groove of Bcl-2 and inducing apoptosis via the intrinsic pathway in a Bax- and caspase-9-dependent manner.
    Matched MeSH terms: Chromans/pharmacology*
  16. Fulltext Proteomic profiling of senescent human diploid fibroblasts treated with gamma-tocotrienol
    Tan JK, Jaafar F, Makpol S
    BMC Complement Altern Med, 2018 Nov 29;18(1):314.
    PMID: 30497457 DOI: 10.1186/s12906-018-2383-6
    BACKGROUND: Replicative senescence of human diploid fibroblasts (HDFs) has been used as a model to study mechanisms of cellular aging. Gamma-tocotrienol (γT3) is one of the members of vitamin E family which has been shown to increase proliferation of senescent HDFs. However, the modulation of protein expressions by γT3 in senescent HDFs remains to be elucidated. Therefore, this study aimed to determine the differentially expressed proteins (DEPs) in young and senescent HDFs; and in vehicle- and γT3-treated senescent HDFs using label-free quantitative proteomics.

    METHODS: Whole proteins were extracted and digested in-gel with trypsin. Peptides were detected by Orbitrap liquid chromatography mass spectrometry. Mass spectra were identified and quantitated by MaxQuant software. The data were further filtered and analyzed statistically using Perseus software to identify DEPs. Functional annotations of DEPs were performed using Panther Classification System.

    RESULTS: A total of 1217 proteins were identified in young and senescent cells, while 1218 proteins in vehicle- and γT3-treated senescent cells. 11 DEPs were found in young and senescent cells which included downregulation of platelet-derived growth factor (PDGF) receptor beta and upregulation of tubulin beta-2A chain protein expressions in senescent cells. 51 DEPs were identified in vehicle- and γT3-treated senescent cells which included upregulation of 70 kDa heat shock protein, triosephosphate isomerase and malate dehydrogenase protein expressions in γT3-treated senescent cells.

    CONCLUSIONS: PDGF signaling and cytoskeletal structure may be dysregulated in senescent HDFs. The pro-proliferative effect of γT3 on senescent HDFs may be mediated through the stimulation of cellular response to stress and carbohydrate metabolism. The expressions and roles of these proteins in relation to cellular senescence are worth further investigations. Data are available via ProteomeXchange with identifier PXD009933.

    Matched MeSH terms: Chromans/pharmacology*
  17. Vitamin E exhibits bone anabolic actions in normal male rats
    Shuid AN, Mehat Z, Mohamed N, Muhammad N, Soelaiman IN
    J. Bone Miner. Metab., 2010 Mar;28(2):149-56.
    PMID: 19779668 DOI: 10.1007/s00774-009-0122-2
    Recently, vitamin E has been found to promote the bone structure of nicotine-treated rats well above their baseline values, thus suggesting that vitamin E may have some anabolic action. A bone anabolic agent acts by improving the bone structure leading to stronger bone. To assess the possible anabolic action vitamin E on bone, we supplemented alpha-tocopherol (ATF) or gamma-tocotrienol (GTT) at 60 mg/kg or vehicle [normal control (NC) group] for 4 months to normal male rats and measured their bone structure and biomechanical properties. Histomorphometric analysis revealed that vitamin E-supplemented rats have better trabecular volume, thickness, number, and separation than rats receiving vehicle only. For the first time we reported that GTT improves all the parameters of bone biomechanical strength, while ATF only improved some of the parameters compared to the NC group. Vitamin E supplementation, especially with the gamma isomer, improves bone structure, which contributed to stronger bone. Therefore, vitamin E has the potential to be used as an anabolic agent to treat osteoporosis or as bone supplements for young adults to prevent osteoporosis in later years.
    Matched MeSH terms: Chromans/administration & dosage
  18. Fulltext Pure tocotrienol concentrate protected rat gastric mucosa from acute stress-induced injury by a non-antioxidant mechanism
    Rodzian MN, Aziz Ibrahim IA, Nur Azlina MF, Nafeeza MI
    Pol J Pathol, 2013 Apr;64(1):52-8.
    PMID: 23625601
    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% δ-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.
    Matched MeSH terms: Chromans/pharmacology
  19. Fulltext Antioxidant activity and total phenolic content in aqueous extracts of selected traditional Malay salads (Ulam)
    Reihani, S.F.S., Azhar, M.E.
    International Food Research Journal, 2012;19(4):1439-1444.
    MyJurnal
    The total phenolic contents (TPC) and antioxidant activities of five popular Malay raw salads or Ulam were investigated using DPPH radical scavenging and reducing ferric ion antioxidant power (FRAP) assays. The Ulam studied were the leaves of Cosmos caudatus (Ulam Raja), Oenanthe javanica (Selom), Murraya koenigii (Curry Leaf), Centella asiatica (Pegaga) and the seeds of Parkia speciosa (Petai). Ranking order of TPC (mg gallic acid equivalent per gram of plant on dry basis), TEACDPPH (µmol Trolox equivalent per gram of plant on dry basis) and TEACFRAP (µmol Trolox equivalent per gram of plant on dry basis) values were: Curry Leaf (33.18), Selom (31.8), Ulam Raja (31.3) > Pegaga (11.16) > Petai (6.45); Ulam Raja (212.8) > Selom (185.9) > Curry Leaf (82.1), Petai (67.62) > Pegaga (32.4); Selom (199.96) > Ulam Raja (183.11) > Curry Leaf (108.34) > Pegaga (65.99) > Petai (44.67), respectively. No significant correlation (p>0.05) was observed between antioxidant activities and TPC which could be due to steric hindrance or presence of other reducing agents. Interestingly, Selom showed antioxidant activities that are comparable to Ulam Raja.
    Matched MeSH terms: Chromans
  20. Deleterious effects of nicotine on the ultrastructure of oocytes: role of gamma-tocotrienol
    Rajikin MH, Latif ES, Mar MR, Mat Top AG, Mokhtar NM
    Med Sci Monit, 2009 Dec;15(12):BR378-83.
    PMID: 19946227
    Previous studies have shown that nicotine enhances oxidative DNA damage and leads to increased lipid peroxidation, which affects embryo development. The present study investigated the effect of daily supplementation of gamma-tocotrienol on oocytes of nicotine-treated mice.
    Matched MeSH terms: Chromans/administration & dosage; Chromans/pharmacology*
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