Displaying publications 1 - 20 of 27 in total

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  1. Antiproliferation and induction of caspase-8-dependent mitochondria-mediated apoptosis by β-tocotrienol in human lung and brain cancer cell lines
    Lim SW, Loh HS, Ting KN, Bradshaw TD, Zeenathul NA
    Biomed Pharmacother, 2014 Oct;68(8):1105-15.
    PMID: 25456851 DOI: 10.1016/j.biopha.2014.10.006
    The pure vitamin isomer, β-tocotrienol has the least abundance among the other vitamin E isomers that are present in numerous plants. Hence, it is very scarcely studied for its bioactivity. In this study, the antiproliferative effects and primary apoptotic mechanisms of β-tocotrienol on human lung adenocarcinoma A549 and glioblastoma U87MG cells were investigated. It was evidenced that β-tocotrienol had inhibited the growth of both A549 (GI50=1.38±0.334μM) and U87MG (GI50=2.53±0.604μM) cells at rather low concentrations. Cancer cells incubated with β-tocotrienol were also found to exhibit hallmarks of apoptotic morphologies including membrane blebbing, chromatin condensation and formation of apoptotic bodies. The apoptotic properties of β-tocotrienol in both A549 and U87MG cells were the results of its capability to induce significant (P<0.05) double-strand DNA breaks (DSBs) without involving single-strand DNA breaks (SSBs). β-Tocotrienol is said to induce activation of caspase-8 in both A549 and U87MG cells guided by no activation when caspase-8 inhibitor, z-IETD-fmk was added. Besides, disruption on the mitochondrial membrane permeability of the cells in a concentration- and time-dependent manner had occurred. The induction of apoptosis by β-tocotrienol in A549 and U87MG cells was confirmed to involve both the death-receptor mediated and mitochondria-dependent apoptotic pathways. These findings could potentiate the palm oil derived β-tocotrienol to serve as a new anticancer agent for treating human lung and brain cancers.
    Matched MeSH terms: Vitamin E/therapeutic use
  2. Comparative effect of palm vitamin E and ranitidine on the healing of ethanol-induced gastric lesions in rats
    Jaarin K, Renuvathani M, Nafeeza MI, Gapor MT
    Int J Exp Pathol, 1999 Oct;80(5):259-63.
    PMID: 10607016
    The effect of palm vitamin E on the healing of ethanol-induced gastric lesion was compared with ranitidine. Fifty-six male rats of Sprague-Dawley species (200-250 g of weight) were randomly divided into three groups (N = 14). Gastric mucosal injury was induced by orogastric tube administration of 0.5 ml 100% ethanol. Immediately after induction, Group I (k) rats was fed with a normal diet (control), group II (p) was fed palm vitamin E enriched diet (150 mg/kg food), Group III(r) was treated with ranitidine 30 mg/kg body weight intraperitoneally and Group IV (p + r) was fed with palm vitamin E and treated with ranitidine 30 mg/kg body weight intraperitoneally of the same dose. The rats were killed at the end of 1 week and 3 weeks of treatment or feeding. The rate of gastric healing was faster in palm vitamin E treated group compared to control and ranitidine treated groups as shown by a lower mean ulcer index. The effect was seen as early as the first week of treatment whereas ranitidine did not show any healing effect even after 3 weeks of therapy. Neither gastric acidity nor gastric mucus production are involved in gastroprotective effect of palm vitamin E. The most probable mechanism is via reducing lipid peroxidation process as shown by a significant decrease in gastric MDA.
    Matched MeSH terms: Vitamin E/therapeutic use*
  3. Comparative effects of alpha-tocopherol and gamma-tocotrienol against hydrogen peroxide induced apoptosis on primary-cultured astrocytes
    Mazlan M, Sue Mian T, Mat Top G, Zurinah Wan Ngah W
    J Neurol Sci, 2006 Apr 15;243(1-2):5-12.
    PMID: 16442562
    Oxidative stress is thought to be one of the factors that cause neurodegeneration and that this can be inhibited by antioxidants. Since astrocytes support the survival of central nervous system (CNS) neurons, we compared the effect of alpha-tocopherol and gamma-tocotrienol in minimizing the cytotoxic damage induced by H(2)O(2), a pro-oxidant. Primary astrocyte cultures were pretreated with either alpha-tocopherol or gamma-tocotrienol for 1 h before incubation with 100 microM H(2)O(2) for 24 h. Cell viability was then assessed using the MTS assay while apoptosis was determined using a commercial ELISA kit as well as by fluorescent staining of live and apoptotic cells. The uptake of alpha-tocopherol and gamma-tocotrienol by astrocytes were also determined using HPLC. Results showed that gamma-tocotrienol is toxic at concentrations >200 microM but protects against H(2)O(2) induced cell loss and apoptosis in a dose dependent manner up to 100 microM. alpha-Tocopherol was not cytotoxic in the concentration range tested (up to 750 microM), reduced apoptosis to the same degree as that of gamma-tocotrienol but was less effective in maintaining the viable cell number. Since the uptake of alpha-tocopherol and gamma-tocotrienol by astrocytes is similar, this may reflect the roles of these 2 vitamin E subfamilies in inhibiting apoptosis and stimulating proliferation in astrocytes.
    Matched MeSH terms: Vitamin E/therapeutic use
  4. Fulltext Comparative efficacy of interventions on nonalcoholic fatty liver disease (NAFLD): A PRISMA-compliant systematic review and network meta-analysis
    Sawangjit R, Chongmelaxme B, Phisalprapa P, Saokaew S, Thakkinstian A, Kowdley KV, et al.
    Medicine (Baltimore), 2016 Aug;95(32):e4529.
    PMID: 27512874 DOI: 10.1097/MD.0000000000004529
    The prevalence of nonalcoholic fatty liver disease (NAFLD) has significantly increased over the last decades. Despite existence of several interventions, there remains unclear which interventions work the best.
    Matched MeSH terms: Vitamin E/therapeutic use
  5. Fulltext Cytotoxicity and apoptotic activities of alpha-, gamma- and delta-tocotrienol isomers on human cancer cells
    Lim SW, Loh HS, Ting KN, Bradshaw TD, Zeenathul NA
    BMC Complement Altern Med, 2014;14:469.
    PMID: 25480449 DOI: 10.1186/1472-6882-14-469
    Tocotrienols, especially the gamma isomer was discovered to possess cytotoxic effects associated with the induction of apoptosis in numerous cancers. Individual tocotrienol isomers are believed to induce dissimilar apoptotic mechanisms in different cancer types. This study was aimed to compare the cytotoxic potency of alpha-, gamma- and delta-tocotrienols, and to explore their resultant apoptotic mechanisms in human lung adenocarcinoma A549 and glioblastoma U87MG cells which are scarcely researched.
    Matched MeSH terms: Vitamin E/therapeutic use
  6. Does palm oil vitamin E reduce the risk of pregnancy induced hypertension?
    Mahdy ZA, Siraj HH, Khaza'ai H, Mutalib MS, Azwar MH, Wahab MA, et al.
    Acta Medica (Hradec Kralove), 2013;56(3):104-9.
    PMID: 24592747
    In view of the high anti-oxidative potential oftocotrienol, the role of the tocotrienol-rich fraction (TRF) of palm oil in preventing pregnancy induced hypertension (PIH) was explored in a randomized double-blind placebo-controlled clinical trial in an urban teaching hospital. Healthy primigravidae were randomized to receive either oral TRF 100 mg daily or placebo, from early second trimester until delivery. Out of 299 women, 151 were randomized into the TRF arm and 148 into the placebo arm. A total of 15 (5.0%) developed PIH. Although there was no statistically significant difference in the incidence of PIH (4/151 or 2.6% in the TRF arm vs. 11/148 or 7.4% in the placebo arm, p = 0.058) between the two arms, there was a tendency towards a lower incidence of PIH in the TRF arm compared to the placebo arm. With TRF supplementation, the relative risk (RR) of PIH was 0.36 (95% CI 0.12-1.09). In conclusion, although TRF from palm oil does not statistically significantly reduce the risk of development of PIH in the population studied, the 64% reduction in incidence of PIH is substantial. The findings warrant further clinical trials, particularly in high risk populations.
    Matched MeSH terms: Vitamin E/therapeutic use*
  7. Effect of alpha-tocopherol on lipid peroxidation and total antioxidant status in spontaneously hypertensive rats
    Newaz MA, Nawal NN
    Am J Hypertens, 1998 Dec;11(12):1480-5.
    PMID: 9880131
    The aim of this study was to determine the effects of alpha-tocopherol on lipid peroxidation and total antioxidant status of spontaneously hypertensive rats (SHR), comparing them with normal Wistar-Kyoto (WKY) rats. SHR were divided into three groups and treated with different doses of alpha-tocopherol (alpha1, 17 mg/kg diet; alpha2, 34 mg/kg diet; and alpha3, 170 mg/kg diet). Normal WKY and untreated SHR were used as normal (N) and hypertensive control (HC). Blood pressures were recorded every 10 days for 3 months. At the end of the trial, animals were killed and measurement of plasma total antioxidant status, plasma superoxide dismutase (SOD) activity, and lipid peroxide levels in plasma and blood vessels was carried out following well-established methods. From our study it was found that lipid peroxides in thoracic aorta (N, 0.47 +/- 0.17; H, 0.96 +/- 0.37; P < .0001) and plasma (N, 0.06 +/- 0.01; H, 0.13 +/- 0.01) were significantly higher in hypertensives than in normal rats. SOD activity was significantly lower in hypertensive than normal rats (N, 172.93 +/- 46.91; H, 110.08 +/- 14.38; P < .005). Total antioxidant status was significantly higher in normal than hypertensive rats (N, 0.88 +/- 0.05; H, 0.83 +/- 0.02; P < .05). After the antioxidant trial, it was found that in the treated groups rise of blood pressure was prevented significantly (P < .001) and lipid peroxides in blood vessels were significantly reduced more than in the controls (P < .001). For plasma lipid peroxide it was only significant for groups alpha2 (P < .001) and alpha3 (P < .05). Although all three treated groups showed improved total antioxidant status, only groups alpha2 (0.87 +/- 0.04, P < .005) and alpha3 (1.20 +/- 0.18, P < .001) were statistically significant. All the three groups showed significant increases in their SOD activity (P < .001). Correlation studies showed that total antioxidant status and SOD were significantly negatively correlated with blood pressure in normal rats (P = .007; P = .008). Lipid peroxides in both blood vessel and plasma showed a positive correlation. In the treated groups, lipid peroxides in blood vessels maintained a significant positive correlation with blood pressure in all groups (alpha1, P = .021; alpha2, P = .019; alpha3, P = .002), whereas for plasma lipid peroxides the correlation was in groups alpha1 (P = .005) and alpha2 (P = .009). For SOD activity, significant negative correlations were found with blood pressure in the alpha2 (P = .017) and alpha3 (P = .025) groups. Total antioxidant status maintained a significant negative correlation with blood pressure in all three groups (alpha1, P = .012; alpha2, P = .044; alpha3, P = .014). In conclusion it was found that supplement of alpha-tocopherol may prevent development of increased blood pressure, reduce lipid peroxides in plasma and blood vessels, and enhance the total antioxidant status, including SOD activity.
    Matched MeSH terms: Vitamin E/therapeutic use
  8. Effect of palm vitamin E on the healing of ethanol-induced gastric injury in rats
    Jaarin K, Renuvathani M, Nafeeza MI, Gapor MT
    Int J Food Sci Nutr, 2000;51 Suppl:S31-41.
    PMID: 11271855
    The effect of palm vitamin E on the healing of ethanol-induced gastric lesions and various biochemical parameters were investigated. The study was divided into two phases. In the first phase of the study, 42 rats of Sprague Dawley species (200-250 gm weight) were randomly divided into two groups fed with a normal diet (control) or palm vitamin E enriched diet (150 mg/kg) for 3 weeks. The rats were killed after 3 weeks of feeding. Gastric tissue contents of malondialdehyde (MDA), prostaglandin E2 and acid were measured. In the second phase of the study 42 rats were divided into two groups. Group 1 was fed normal rat pellets (control) and group 2 was fed palm vitamin E enriched pellets (150 mg/kg food) for 3 weeks. After 3 weeks of feeding gastric mucosal injury was induced by an orogastric tube administration of 0.5 ml 100% ethanol. The rats were killed at 1 hour, 4 hours and 1 week after ethanol exposure for semiquantitative determination of ulcer index and gastric acid concentration. Gastric tissue MDA and mucus were measured only at 1 week after ethanol exposure. In the first phase of the study we found that palm vitamin E only caused a significant reduction in gastric MDA. However, it showed no significant effects on prostaglandin E2 and gastric acid concentration. In the second phase of the study, the mean ulcer index of palm vitamin E supplemented group killed after 1 week of ethanol exposure was significantly lower compared to the respective control. However, there was no significant difference in ulcer index in rats killed at 1 hour and 24 hours after ethanol exposure. The gastric acid concentration was significantly higher in the group treated with palm vitamin E killed 1 week after ethanol exposure compared to control. The gastric tissue MDA was significantly lower in the palm vitamin E supplemented group compared to control. There was no significant difference in gastric mucus content of the both groups. The ulcer healing which occurred in the presence of a high gastric acid suggests that the effect of palm vitamin E on the healing of gastric lesions was not mediated via a reduction in gastric acid nor was it mediated through increasing prostaglandin E2 or mucus production. The most probable mechanism is via reducing lipid peroxidation as reflected by a significant decreased in gastric tissue MDA content.
    Matched MeSH terms: Vitamin E/therapeutic use*
  9. Effect of tocotrienols on hepatocarcinogenesis induced by 2-acetylaminofluorene in rats
    Ngah WZ, Jarien Z, San MM, Marzuki A, Top GM, Shamaan NA, et al.
    Am J Clin Nutr, 1991 04;53(4 Suppl):1076S-1081S.
    PMID: 1672785 DOI: 10.1093/ajcn/53.4.1076S
    The effects of tocotrienols on hepatocarcinogenesis in rats fed with 2-acetylaminofluorene (AAF) were followed morphologically and histologically for a period of 20 wk. No differences between treated and control rats in the morphology and histology of their livers was observed. Cell damage was extensive in the livers of AAF-treated rats but less extensive in the AAF-tocotrienols-treated rats when compared with normal and tocotrienols-treated rats. 2-Acetylaminofluorene significantly increases the activities of both plasma and liver microsomal gamma-glutamyltranspeptidase (GGT) and liver microsomal UDP-glucuronyltransferase (UDP-GT). Tocotrienols administered together with AAF significantly decrease the activities of plasma GGT after 12 and 20 wk (P less than 0.01, P less than 0.002, respectively) and liver microsomal UDP-GT after 20 wk (P less than 0.02) when compared with the controls and with rats treated only with tocotrienols. Liver microsomal GGT also showed a similar pattern to liver microsomal UDP-GT but the decrease was not significant. These results suggest that tocotrienols administered to AAF-treated rats reduce the severity of hepatocarcinogenesis.
    Matched MeSH terms: Vitamin E/therapeutic use
  10. Fulltext Effect of various doses of palm vitamin E and tocopherol on aspirin-induced gastric lesions in rats
    Jaarin K, Gapor MT, Nafeeza MI, Fauzee AM
    Int J Exp Pathol, 2002 Dec;83(6):295-302.
    PMID: 12657138 DOI: 10.1046/j.1365-2613.2002.00242.x
    This study examined the effects of vitamin E on the prevention of aspirin-induced gastric lesions. The study was divided into two phases. Phase 1 determined the effects of various doses of palm vitamin E on the factors affecting mucosal integrity. Thirty-two male rats of the Sprague-Dawley strain (200-250 g) were randomly divided into four groups. Group I was fed a normal diet (control), Groups II, III and IV were fed a diet supplemented with palm vitamin E in a dose of 60 mg/kg food, 100 mg/kg food and 150 mg/kg food, respectively. The rats were killed after 4 weeks of feeding for the determination of gastric malondialdehyde (MDA), acid and mucus content. There was a significant decrease in gastric MDA and gastric acid in all the palm vitamin E supplemented groups compared to control. However, these doses of palm vitamin E had no significant effect on gastric mucus. The phase 2 study determined the effect of multiple doses of palm vitamin E and tocopherol on the prevention of aspirin-induced gastric lesions. Fifty rats of the same weight and strain were randomized into seven groups. Group I was fed a normal diet; groups II to IV were fed with a palm vitamin E enriched diet in doses of 60 mg, 100 mg and 150 mg/kg food, respectively; groups V to VII were fed with a tocopherol-enriched diet in doses of 20 mg, 30 mg and 50 mg/kg food, respectively. After 4 weeks of feeding with the respective diets the rats were challenged with a single intra-gastric dose of 400 mg/kg body weight aspirin suspended in propylene glycol. The rats were killed 6 h post-aspirin exposure for the determination of gastric lesion index and gastric parameters as mentioned in the phase I study. The gastric lesions index was significantly lower in all the vitamin E groups compared to control. The lowest ulcer index was observed in the groups that received 100 mg of palm vitamin E and 30 mg tocopherol in the diet. However, there was no significant difference in ulcer indices between palm vitamin E and tocopherol-treated groups. The lower ulcer index was only accompanied by lower gastric MDA content. We conclude that both palm vitamin E in doses of 60 mg, 100 mg and 150 mg/kg food as well as tocopherol in doses of 20 mg, 30 mg and 50 mg/kg food are equally effective in preventing aspirin-induced gastric lesions. The most probable mechanism is through their ability in limiting the lipid peroxidation that is involved in aspirin-induced gastric lesions.
    Matched MeSH terms: Vitamin E/therapeutic use*
  11. Effect of vitamin E on periodontitis: Evidence and proposed mechanisms of action
    Shadisvaaran S, Chin KY, Shahida MS, Ima-Nirwana S, Leong XF
    J Oral Biosci, 2021 06;63(2):97-103.
    PMID: 33864905 DOI: 10.1016/j.job.2021.04.001
    BACKGROUND: Periodontitis is a noncommunicable inflammatory disease of the soft tissue and bone surrounding the teeth in the jaw, which affects susceptible individuals with poor oral hygiene. A growing interest has been seen in the use of dietary supplements and natural products for the treatment and prevention of periodontitis. Vitamin E consists of two major groups, namely tocopherols and tocotrienols, which are botanical lipophilic compounds with excellent anti-inflammatory and antioxidant properties.

    HIGHLIGHT: This review aimed to summarize the preclinical and clinical findings on the effects of vitamin E on periodontitis. The current literature suggests that vitamin E could improve the periodontal status by correcting redox status imbalance, reducing inflammatory responses, and promoting wound healing, thus highlighting the potential of vitamin E in the management of periodontitis.

    CONCLUSION: Direct evidence for the use of vitamin E supplementation or treatment of periodontitis in humans is still limited. More well-designed and controlled studies are required to ascertain its effectiveness.

    Matched MeSH terms: Vitamin E/therapeutic use
  12. Fulltext Effects of emulsified and non-emulsified palm tocotrienol on bone and joint health in ovariectomised rats with monosodium iodoacetate-induced osteoarthritis
    Ekeuku SO, Nor Muhamad ML, Aminuddin AA, Ahmad F, Wong SK, Mark-Lee WF, et al.
    Biomed Pharmacother, 2024 Jan;170:115998.
    PMID: 38091638 DOI: 10.1016/j.biopha.2023.115998
    Postmenopausal women are susceptible to osteoporosis and osteoarthritis. Tocotrienol, a bone-protective nutraceutical, is reported to prevent osteoarthritis in male rats. However, its efficacy on joint health in oestrogen deficiency has not been validated. Besides, data on the use of emulsification systems in enhancing bioavailability and protective effects of tocotrienol are limited. Ovariectomised adult female Sprague-Dawley rats (3 months old) were treated with refined olive oil, emulsified (EPT, 100 mg/kg/day with 25% vitamin E content), non-emulsified palm tocotrienol (NEPT, 100 mg/kg/day with 50% vitamin E content) and calcium carbonate (1% w/v in drinking water) plus glucosamine sulphate (250 mg/kg/day) for 10 weeks. Osteoarthritis was induced with monosodium iodoacetate four weeks after ovariectomy. Baseline control was sacrificed upon receipt, while the sham group was not ovariectomised and treated with refined olive oil. EPT and NEPT prevented femoral metaphyseal and subchondral bone volume decline caused by ovariectomy. EPT decreased subchondral trabecular separation compared to the negative control. EPT preserved stiffness and Young's Modulus at the femoral mid-shaft of the rats. Circulating RANKL was reduced post-treatment in the EPT group. Joint width was reduced in all the treatment groups vs the negative control. The EPT group's grip strength was significantly improved over the negative control and NEPT group. EPT also preserved cartilage histology based on several Mankin's subscores. EPT performed as effectively as NEPT in preventing osteoporosis and osteoarthritis in ovariectomised rats despite containing less vitamin E content. This study justifies clinical trials for the use of EPT in postmenopausal women with both conditions.
    Matched MeSH terms: Vitamin E/therapeutic use
  13. Fulltext Effects of vitamin E supplementation on bone metabolism in nicotine-treated rats
    Norazlina M, Lee PL, Lukman HI, Nazrun AS, Ima-Nirwana S
    Singapore Med J, 2007 Mar;48(3):195-9.
    PMID: 17342286
    Nicotine has been shown to exert negative effects on bone. This study determined whether vitamin E supplementation is able to repair the nicotine-induced adverse effects in bone.
    Matched MeSH terms: Vitamin E/therapeutic use*
  14. Inhibition of tumour promotion by various palm-oil tocotrienols
    Goh SH, Hew NF, Norhanom AW, Yadav M
    Int J Cancer, 1994 May 15;57(4):529-31.
    PMID: 8181855
    Inhibition of tumour promotion by various vitamin E compounds (tocopherols and tocotrienols) and some of their dimers was examined by an in vitro assay utilizing the activation of Epstein-Barr virus (EBV) early antigen (EA) expression in EBV-genome-carrying human lymphoblastoid cells. The results reveal that gamma- and delta-tocotrienols derived from palm oil exhibit a strong activity against tumour promotion by inhibiting EBV EA expression in Raji cells induced by 12-O-tetradecanoylphorbol-13-acetate (TPA). However, alpha- and gamma-tocopherols and dimers of gamma-tocotrienol or gamma-tocopherol lack this activity.
    Matched MeSH terms: Vitamin E/therapeutic use*
  15. Fulltext Palm vitamin E reduces catecholamines, xanthine oxidase activity and gastric lesions in rats exposed to water-immersion restraint stress
    Mohd Fahami NA, Ibrahim IA, Kamisah Y, Mohd Ismail N
    BMC Gastroenterol, 2012;12:54.
    PMID: 22639913 DOI: 10.1186/1471-230X-12-54
    This study examined the effects of Palm vitamin E (PVE) and α-tocopherol (α-TF) supplementations on adrenalin, noradrenalin, xanthine oxidase plus dehydrogenase (XO + XD) activities and gastric lesions in rats exposed to water-immersion restraint stress (WIRS).
    Matched MeSH terms: Vitamin E/therapeutic use*
  16. Fulltext Palm vitamin E reduces locomotor dysfunction and morphological changes induced by spinal cord injury and protects against oxidative damage
    Zadeh-Ardabili PM, Rad SK, Rad SK, Khazaài H, Sanusi J, Zadeh MH
    Sci Rep, 2017 10 30;7(1):14365.
    PMID: 29085045 DOI: 10.1038/s41598-017-14765-3
    Spinal cord injury (SCI) occurs following different types of crushes. External and internal outcomes of SCI are including paralysis, cavity, and cyst formation. Effects of dietary derived antioxidants, such as palm vitamin E on central nervous system (CNS) encourage researchers to focus on the potential therapeutic benefits of antioxidant supplements. In the present study, experiments were carried out to evaluate the neuro-protective effect of the palm vitamin E on locomotor function and morphological damages induced SCI. Seventy-two male rats (Sprague-Dawley) were randomly divided into four groups: sham (laminectomy); control (supplemented with the palm vitamin E at a dose of 100 mg/kg/day); untreated-SCI (partial crush, 30-33% for 20 sec); treated-SCI (partial crush, 30-33% for 20 sec supplemented with the palm vitamin E at a dose of 100 mg/kg/day). The treatment with the palm vitamin E significantly improved the hind limb locomotor function, reduced the histopathological changes and the morphological damage in the spinal cord. Also, the palm vitamin E indicated a statistically significant decrease in the oxidative damage indicators, malondialdehyde (MDA) level and glutathione peroxidase (GPx) activity in the treated-SCI compared to the untreated-SCI.
    Matched MeSH terms: Vitamin E/therapeutic use*
  17. Fulltext Peripheral haemolysis, lipid peroxidation, iron status, and vitamin E in haemoglobin H syndromes in West Malaysia
    George E, Wong HB, Jamaluddin M, Huisman TH
    Singapore Med J, 1993 Jun;34(3):241-4.
    PMID: 8266182
    Following complete DNA characterisation patients with Hb H disease were assigned into two groups: deletional (alpha +/alpha o) and non deletional (HbCS/alpha o). Earlier studies have indicated that the group with (HbCS/alpha o) has more severe clinical problems. The serum malonyldialdehyde (MDA) levels, a secondary product of lipid peroxidation were within the normal range, though significantly higher levels of MDA were seen in the non-deletional type of Hb H disease when compared with the deletional type. Markedly low vitamin E levels were also seen in the former group. There were no significant differences in clinical severity may be attributed to an interplay of the accelerated destruction of damaged mature red blood cells secondary to the oxidative denaturation of Hb H and inclusion precipitation; higher levels of Hb H and more inclusion precipitation were seen in the group with (HbCS/alpha o). Low levels of vitamin E in the (HbCS/alpha o) group being due to its consumption in the neutralisation of free radicals formed with the oxidation of globin chains.
    Matched MeSH terms: Vitamin E/therapeutic use
  18. Fulltext Protection by tocotrienols against hypercholesterolaemia and atheroma (letter)
    Pathmanathan R, Wong KT
    Med J Malaysia, 1995 Mar;50(1):117.
    PMID: 7752967
    Comment on: Teoh MK, Chong JM, Mohamed J, Phang KS. Protection by tocotrienols against hypercholesterolaemia and atheroma. Med J Malaysia. 1994 Sep;49(3):255-62
    Matched MeSH terms: Vitamin E/therapeutic use
  19. Fulltext Protection by tocotrienols against hypercholesterolaemia and atheroma.
    Teoh MK, Chong JMK, Mohamed J, Phang KS
    Med J Malaysia, 1994 Sep;49(3):255-62.
    PMID: 7845276
    Antioxidants such as tocotrienols may protect against atherosclerosis since tissue injury from free radicals is a final common pathway of damage in arterial disease. In this study, the effects of tocotrienols on serum cholesterol, lipid peroxides, and aorta atheroma were assessed in rabbits fed an atherogenic diet for 12 weeks. Tocotrienols were more effective than tocopherols in preventing increases in serum LDL (p = 0.03) and total cholesterol (p = 0.008) levels in the cholesterol-fed rabbits. Elevation of serum lipid peroxides was effectively suppressed by tocotrienols (p = 0.01). Both tocopherols and tocotrienols offered significant protection against atheroma in the rabbit aorta, but tocotrienols had a stronger hypolipidaemic effect.
    Comment in: Pathmanathan R, Wong KT. Protection by tocotrienols against hypercholesterolaemia and atheroma. Med J Malaysia. 1995 Mar;50(1):117
    Matched MeSH terms: Vitamin E/therapeutic use
  20. The role of oxidative stress, antioxidants and vascular inflammation in cardiovascular disease (a review)
    Siti HN, Kamisah Y, Kamsiah J
    Vascul. Pharmacol., 2015 Aug;71:40-56.
    PMID: 25869516 DOI: 10.1016/j.vph.2015.03.005
    The concept of mild chronic vascular inflammation as part of the pathophysiology of cardiovascular disease, most importantly hypertension and atherosclerosis, has been well accepted. Indeed there are links between vascular inflammation, endothelial dysfunction and oxidative stress. However, there are still gaps in our understanding regarding this matter that might be the cause behind disappointing results of antioxidant therapy for cardiovascular risk factors in large-scale long-term randomised controlled trials. Apart from the limitations of our knowledge, limitations in methodology and assessment of the body's endogenous and exogenous oxidant-antioxidant status are a serious handicap. The pleiotropic effects of antioxidant and anti-inflammation that are shown by some well-established antihypertensive agents and statins partly support the idea of using antioxidants in vascular diseases as still relevant. This review aims to provide an overview of the links between oxidative stress, vascular inflammation, endothelial dysfunction and cardiovascular risk factors, importantly focusing on blood pressure regulation and atherosclerosis. In view of the potential benefits of antioxidants, this review will also examine the proposed role of vitamin C, vitamin E and polyphenols in cardiovascular diseases as well as the success or failure of antioxidant therapy for cardiovascular diseases in clinical trials.
    Matched MeSH terms: Vitamin E/therapeutic use
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