Displaying publications 161 - 180 of 293 in total

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  1. Chan KW, Ismail M, Mohd Esa N, Mohamed Alitheen NB, Imam MU, Ooi J, et al.
    Oxid Med Cell Longev, 2018;2018:6742571.
    PMID: 29849908 DOI: 10.1155/2018/6742571
    The present study aimed to investigate the antioxidant and anti-inflammatory properties of defatted kenaf seed meal (DKSM) and its phenolic-saponin-rich extract (PSRE) in hypercholesterolemic rats. Hypercholesterolemia was induced using atherogenic diet feeding, and dietary interventions were conducted by incorporating DKSM (15% and 30%) or PSRE (at 2.3% and 4.6%, resp., equivalent to the total content of DKSM-phenolics and saponins in the DKSM groups) into the atherogenic diets. After ten weeks of intervention, serum total antioxidant capacities of hypercholesterolemic rats were significantly enhanced by DKSM and PSRE supplementation (p < 0.05). Similarly, DKSM and PSRE supplementation upregulated the hepatic mRNA expression of antioxidant genes (Nrf2, Sod1, Sod2, Gsr, and Gpx1) of hypercholesterolemic rats (p < 0.05), except for Gpx1 in the DKSM groups. The levels of circulating oxidized LDL and proinflammatory biomarkers were also markedly suppressed by DKSM and PSRE supplementation (p < 0.05). In aggregate, DKSM and PSRE attenuated the hypercholesterolemia-associated oxidative stress and systemic inflammation in rats, potentially by enhancement of hepatic endogenous antioxidant defense via activation of the Nrf2-ARE pathway, which may be contributed by the rich content of phenolics and saponins in DKSM and PSRE. Hence, DKSM and PSRE are prospective functional food ingredients for the potential mitigation of atherogenic risks in hypercholesterolemic individuals.
    Matched MeSH terms: Glutathione Reductase/genetics; Glutathione Reductase/metabolism
  2. Looi ML, Mohd Dali AZ, Md Ali SA, Wan Ngah WZ, Mohd Yusof YA
    Eur J Cancer Prev, 2008 Nov;17(6):555-60.
    PMID: 18941377 DOI: 10.1097/CEJ.0b013e328305a10b
    Free radicals that induced lipid peroxidation and DNA damage have been implicated in many diseases including cancer. Cellular antioxidant defense plays an important role in neoplastic disease to counteract oxidative damage. This study aims to investigate the status of oxidative damage by measuring plasma malondialdehyde (MDA) level and urinary 8-hydroxydeoxyguanosine (8-OHdG), and the level of antioxidant enzymes superoxide dismutase, glutathione peroxidase, and catalase in patients with cervical intraepithelial neoplasia (CIN) and squamous cell carcinoma (SCC) of the cervix. Urinary 8-OHdG was measured by an enzyme-linked immunosorbent assay kit. MDA and antioxidant enzyme activities were determined by high-performance liquid chromatography and spectrophotometry, respectively. Eighty patients with CIN and SCC of the cervix were recruited and compared with normal controls. Urinary 8-OHdG/creatinine ratio did not show any significant changes in any disease status studied as compared with controls (P=0.803). Plasma MDA was found to be increased in CIN and SCC patients when compared with controls (P=0.002). Glutathione peroxidase activity was increased (P=0.0001) whereas superoxide dismutase and catalase activity was decreased (P=0.019 and 0.0001, respectively) in both CIN and SCC patients when compared with controls. Urinary 8-OHdG may not be a good marker for enhanced oxidative stress in cervical cancer. Oxidative damage as demonstrated by the level of MDA is markedly increased in CIN and SCC patients with changes of enzymatic antioxidants observed.
    Matched MeSH terms: Glutathione Peroxidase/blood; Glutathione Peroxidase/metabolism
  3. Latif A, Hussain K, Shehzadi N, Islam M, Khan MT, Anwar R, et al.
    Pharm Biol, 2017 Dec;55(1):547-553.
    PMID: 27951746
    CONTEXT: Kanji, a liquid preparation of roots of Daucus carota L. ssp. sativus (Hoffm.) Arcang. var. vavilovii Mazk. (Apiaceae), may inhibit glutathione sulfotransferase (GST) activity due to ferulic acid content.

    OBJECTIVES: GST inhibition activity and characterization of Kanji and methanol extract of D. carota roots, and oral absorption pattern of ferulic acid from Kanji in rats.

    MATERIALS AND METHODS: GST inhibition activity of Kanji and methanol extract of D. carota roots in concentration range 0.001-100.00 mg/mL was determined using Sprague Dawley rat liver cytosolic fraction. Methanol extract upon column chromatography gave ferulic acid, which was used to characterize Kanji and determine its oral absorption pattern in Wistar rats.

    RESULTS: The GST inhibition activity of Kanji (100.00 μg/mL), methanol extract of D. carota roots (100.00 μg/mL) and tannic acid (10.00 μg/mL, positive control) was found to be 0.162 ± 0.016, 0.106 ± 0.013 and 0.073 ± 0.004 μM/min/mg, respectively. Different Kanji samples and methanol extract contained ferulic acid (0.222-0.316 mg/g) and 0.77 mg/g, respectively. Ferulic acid did not appear in plasma after oral administration of Kanji.

    DISCUSSION: Kanji having solid contents 80.0 μg/mL, equivalent to 0.0025 μg/mL ferulic acid, does not inhibit the activity of GST. The oral administration of Kanji, in human equivalent dose (528 mg/kg, 16.67 μg ferulic acid), to rats indicated poor absorption of ferulic acid.

    CONCLUSION: Kanji having solid contents 14-36 mg/mL does not inhibit GST activity, hence may not interfere with drugs that are the substrates of GST, if taken concomitantly.

    Matched MeSH terms: Glutathione Transferase/antagonists & inhibitors*; Glutathione Transferase/metabolism
  4. Ismail M, Al-Naqeep G, Chan KW
    Free Radic Biol Med, 2010 Mar 01;48(5):664-72.
    PMID: 20005291 DOI: 10.1016/j.freeradbiomed.2009.12.002
    The antioxidant activities of the thymoquinone-rich fraction (TQRF) extracted from Nigella sativa and its bioactive compound, thymoquinone (TQ), in rats with induced hypercholesterolemia were investigated. Rats were fed a semipurified diet supplemented with 1% (w/w) cholesterol and were treated with TQRF and TQ at dosages ranging from 0.5 to 1.5 g/kg and 20 to 100 mg/kg body wt, respectively, for 8 weeks. The hydroxyl radical (OH(.))-scavenging activity of plasma samples collected from experimental rats was measured by electron spin resonance. The GenomeLab Genetic Analysis System was used to study the molecular mechanism that mediates the antioxidative properties of TQRF and TQ. Plasma total cholesterol and low-density-lipoprotein cholesterol levels were significantly decreased in the TQRF- and TQ-treated rats compared to untreated rats. Feeding rats a 1% cholesterol diet for 8 weeks resulted in a significant decrease in plasma antioxidant capacity, as measured by the capacity to scavenge hydroxyl radicals. However, rats treated with TQRF and TQ at various doses showed significant inhibitory activity toward the formation of OH(.) compared to untreated rats. Upon examination of liver RNA expression levels, treatment with TQRF and TQ caused the up-regulation of the superoxide dismutase 1 (SOD1), catalase, and glutathione peroxidase 2 (GPX) genes compared to untreated rats (P<0.05). In support of this, liver antioxidant enzyme levels, including SOD1 and GPX, were also apparently increased in the TQRF- and TQ-treated rats compared to untreated rats (P<0.05). In conclusion, TQRF and TQ effectively improved the plasma and liver antioxidant capacity and enhanced the expression of liver antioxidant genes of hypercholesterolemic rats.
    Matched MeSH terms: Glutathione Peroxidase/biosynthesis; Glutathione Peroxidase/genetics
  5. Ebrahimi R, Faseleh Jahromi M, Liang JB, Soleimani Farjam A, Shokryazdan P, Idrus Z
    Biomed Res Int, 2015;2015:149745.
    PMID: 25695048 DOI: 10.1155/2015/149745
    Lead- (Pb-) induced oxidative stress is known to suppress growth performance and feed efficiency in broiler chickens. In an attempt to describe the specific underlying mechanisms of such phenomenon we carried out the current study. Ninety-six one-day-old broiler chicks were randomly assigned to 2 dietary treatment groups of 6 pen replicates, namely, (i) basal diet containing no lead supplement (control) and (ii) basal diet containing 200 mg lead acetate/kg of diet. Following 3 weeks of experimental period, jejunum samples were collected to examine the changes in gene expression of several nutrient transporters, antioxidant enzymes, and heat shock protein 70 (Hsp70) using quantitative real-time PCR. The results showed that addition of lead significantly decreased feed intake, body weight gain, and feed efficiency. Moreover, with the exception of GLUT5, the expression of all sugar, peptide, and amino acid transporters was significantly downregulated in the birds under Pb induced oxidative stress. Exposure to Pb also upregulated the antioxidant enzymes gene expression together with the downregulation of glutathione S-transferase and Hsp70. In conclusion, it appears that Pb-induced oxidative stress adversely suppresses feed efficiency and growth performance in chicken and the possible underlying mechanism for such phenomenon is downregulation of major nutrient transporter genes in small intestine.
    Matched MeSH terms: Glutathione Transferase/metabolism
  6. Rahim SM, Taha EM, Al-janabi MS, Al-douri BI, Simon KD, Mazlan AG
    PMID: 25435631
    BACKGROUND: Cymbopogon citratus (Poaceae) a tropical perennial herb plant that is widely cultivated to be eaten either fresh with food or dried in tea or soft drink has been reported to possess a number of medicinal and aromatic properties. This study aimed at evaluating the protective effects of C. citratus aqueous extract against liver injury induced by hydrogen peroxide (H2O2), in male rats.

    MATERIALS AND METHODS: Twenty-five rats were randomly divided into five different groups of five animals in each group; (1) Control. (2) Received H2O2 (0.5%) with drinking water. (3), and (4) received H2O2 and C. citratus (100 mg·kg(-1) b wt), vitamin C (250 mg·kg(-1) b wt) respectively. (5), was given C. citratus alone. The treatments were administered for 30 days. Blood samples were collected and serum was used for biochemical assay including liver enzymes activities, total protein, total bilirubin and malonaldehyde, glutathione in serum and liver homogenates. Liver was excised and routinely processed for histological examinations.

    RESULTS: C. citratus attenuated liver damage due to H2O2 administration as indicated by the significant reduction (p<0.05), in the elevated levels of ALT, AST, ALP, LDH, TB, and MDA in serum and liver homogenates; increase in TP and GSH levels in serum and liver homogenates; and improvement of liver histo-pathological changes. These effects of the extract were similar to that of vitamin C which used as antioxidant reference.

    CONCLUSION: C. citratus could effectively ameliorate H2O2-induced oxidative stress and prevent liver injury in male rats.

    Matched MeSH terms: Glutathione/metabolism
  7. Effendy NM, Shuid AN
    Nutrients, 2014 Aug;6(8):3288-302.
    PMID: 25195641 DOI: 10.3390/nu6083288
    Postmenopausal osteoporosis can be associated with oxidative stress and deterioration of antioxidant enzymes. It is mainly treated with estrogen replacement therapy (ERT). Although effective, ERT may cause adverse effects such as breast cancer and pulmonary embolism. Labisia pumila var. alata (LP), a herb used traditionally for women's health was found to protect against estrogen-deficient osteoporosis. An extensive study was conducted in a postmenopausal osteoporosis rat model using several LP doses and duration of treatments to determine if anti-oxidative mechanisms were involved in its bone protective effects. Ninety-six female Sprague-Dawley rats were randomly divided into six groups; baseline group (BL), sham-operated (Sham), ovariectomised control (OVXC), ovariectomised (OVX) and given 64.5 μg/kg of Premarin (ERT), ovariectomised and given 20 mg/kg of LP (LP20) and ovariectomised and given 100 mg/kg of LP (LP100). The groups were further subdivided to receive their respective treatments via daily oral gavages for three, six or nine weeks of treatment periods. Following euthanization, the femora were dissected out for bone oxidative measurements which include superoxide dismutase (SOD), glutathione peroxidase (GPx) and malondialdehyde (MDA) levels.
    Matched MeSH terms: Glutathione Peroxidase/metabolism
  8. Rajah T, Chow SC
    Toxicol Appl Pharmacol, 2014 Jul 15;278(2):100-6.
    PMID: 24768707 DOI: 10.1016/j.taap.2014.04.014
    The caspase inhibitor benzyloxycarbony (Cbz)-l-Val-Ala-Asp (OMe)-fluoromethylketone (z-VAD-FMK) has recently been shown to inhibit T cell proliferation without blocking caspase-8 and caspase-3 activation in primary T cells. We showed in this study that z-VAD-FMK treatment leads to a decrease in intracellular glutathione (GSH) with a concomitant increase in reactive oxygen species (ROS) levels in activated T cells. The inhibition of anti-CD3-mediated T cell proliferation induced by z-VAD-FMK was abolished by the presence of low molecular weight thiols such as GSH, N-acetylcysteine (NAC) and l-cysteine, whereas d-cysteine which cannot be metabolised to GSH has no effect. These results suggest that the depletion of intracellular GSH is the underlying cause of z-VAD-FMK-mediated inhibition of T cell activation and proliferation. The presence of exogenous GSH also attenuated the inhibition of anti-CD3-induced CD25 and CD69 expression mediated by z-VAD-FMK. However, none of the low molecular weight thiols were able to restore the caspase-inhibitory properties of z-VAD-FMK in activated T cells where caspase-8 and caspase-3 remain activated and processed into their respective subunits in the presence of the caspase inhibitor. This suggests that the inhibition of T cell proliferation can be uncoupled from the caspase-inhibitory properties of z-VAD-FMK. Taken together, the immunosuppressive effects in primary T cells mediated by z-VAD-FMK are due to oxidative stress via the depletion of GSH.
    Matched MeSH terms: Glutathione/metabolism
  9. Al Batran R, Al-Bayaty F, Al-Obaidi MM, Abdulla MA
    Biomed Res Int, 2013;2013:594012.
    PMID: 23844365 DOI: 10.1155/2013/594012
    The aim of the current study is to evaluate the effect of andrographolide on hyperlipidemia induced by Porphyromonas gingivalis in rats. Thirty male Sprague Dawley (SD) rats were divided into five groups as follows: group 1 (vehicle) and four experimental groups (groups 2, 3, 4, and 5) were challenged orally with P. gingivalis ATCC 33277 (0.2 mL of 1.5 ×10(12) bacterial cells/mL in 2% carboxymethylcellulose (CMC) with phosphate-buffered saline (PBS)) five times a week for one month to induce hyperlipidemia. Then, group 3 received a standard oral treatment with simvastatin 100 mg/kg, and groups 4 and 5 received oral treatment with andrographolide 20 mg/kg and 10 mg/kg, respectively, for another month. The results showed that total cholesterol (TC), low-density lipoprotein (LDL-C), and triglycerides (TG) were reduced significantly in groups treated with andrographolide. The malondialdehyde (MDA) level was low in treated groups, while antioxidant enzymes, superoxide dismutase (SOD), and glutathione peroxidase (GPx) were significantly increased in these groups (P < 0.05). Liver tissues of the groups treated with andrographolide reduce the accumulation of lipid droplets in hepatic tissue cells. An acute toxicity test did not show any toxicological symptoms in rats.
    Matched MeSH terms: Glutathione Peroxidase/metabolism
  10. Mohd Esa N, Abdul Kadir KK, Amom Z, Azlan A
    Food Chem, 2013 Nov 15;141(2):1306-12.
    PMID: 23790918 DOI: 10.1016/j.foodchem.2013.03.086
    Antioxidant activity of different rice extract and the effect on the levels of antioxidant enzyme activity, superoxide dismutase (SOD) and glutathione peroxidase (GPx), vitamin E, lipid peroxidation and liver enzymes in hyperlipidaemia rabbits were investigated. Germinated brown rice (GBR) has the highest antioxidant activity compared to white rice (WR) and brown rice (BR). All rice grains increased the activity of SOD and GPx. However, vitamin E levels increased only in the groups that received the BR and GBR diets. The reduction of lipid peroxidation levels and activity of hepatic enzymes (alanine transferase, ALT and aspartate transaminase, AST) were only significantly observed in the GBR group. In conclusion, GBR supplementation has the greatest impact on increasing antioxidant enzyme activity and vitamin E level and on reducing lipid peroxidation in hypercholesterolaemia rabbit, thereby preventing the formation of atherosclerotic plaques. Furthermore, GBR diet can also reduce the level of hepatic enzymes.
    Matched MeSH terms: Glutathione Peroxidase/metabolism
  11. Ng ZX, Chua KH, Iqbal T, Kuppusamy UR
    Int J Mol Sci, 2013;14(4):7480-91.
    PMID: 23552832 DOI: 10.3390/ijms14047480
    This study aims to investigate potential diabetic retinopathy (DR) risk factors by evaluating the circulating levels of pentosidine, soluble receptor for advanced glycation end-product (sRAGE), advanced oxidation protein product (AOPP) as well as glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities in DR patients. A total of 235 healthy controls, 171 type 2 diabetic without retinopathy (DNR) and 200 diabetic retinopathy (DR) patients were recruited. Plasma was extracted for the estimation of pentosidine, sRAGE, AOPP levels and GPx activity whereas peripheral blood mononuclear cells were disrupted for SOD activity measurement. DNR and DR patients showed significantly higher levels of plasma pentosidine, sRAGE and AOPP but lower GPx and SOD activities when compared to healthy controls. The sRAGE/pentosidine ratio in DR patients was significantly lower than the ratio detected in DNR patients. Proliferative DR patients had significantly higher levels of plasma pentosidine, sRAGE, AOPP and sRAGE/pentosidine ratio than non-proliferative DR patients. High HbA1c level, long duration of diabetes and low sRAGE/pentosidine ratio were determined as the risk factors for DR. This study suggests that sRAGE/pentosidine ratio could serve as a risk factor determinant for type 2 DR as it has a positive correlation with the severity of DR.
    Matched MeSH terms: Glutathione Peroxidase/blood
  12. Abdul Hamid Z, Budin SB, Wen Jie N, Hamid A, Husain K, Mohamed J
    J Zhejiang Univ Sci B, 2012 Mar;13(3):176-85.
    PMID: 22374609 DOI: 10.1631/jzus.B1100133
    Paracetamol (PCM) overdose can cause nephrotoxicity with oxidative stress as one of the possible mechanisms mediating the event. In this study, the effects of ethyl acetate extract of Zingiber zerumbet rhizome [200 mg per kg of body weight (mg/kg) and 400 mg/kg] on PCM-induced nephrotoxicity were examined. Rats were divided into five groups containing 10 rats each. The control group received distilled water while other groups were treated with extract alone (400 mg/kg), PCM alone (750 mg/kg), 750 mg/kg PCM+200 mg/kg extract (PCM+200-extract), and 750 mg/kg PCM+400 mg/kg extract (PCM+400-extract), respectively, for seven consecutive days. The Z. zerumbet extract was given intraperitoneally concurrent with oral administration of PCM. Treatment with Z. zerumbet extract at doses of 200 and 400 mg/kg prevented the PCM-induced nephrotoxicity and oxidative impairments of the kidney, as evidenced by a significantly reduced (P<0.05) level of plasma creatinine, plasma and renal malondialdehyde (MDA), plasma protein carbonyl, and renal advanced oxidation protein product (AOPP). Furthermore, both doses were also able to induce a significant increment (P<0.05) of plasma and renal levels of glutathione (GSH) and plasma superoxide dismutase (SOD) activity. The nephroprotective effects of Z. zerumbet extract were confirmed by a reduced intensity of renal cellular damage, as evidenced by histological findings. Moreover, Z. zerumbet extract administered at 400 mg/kg was found to show greater protective effects than that at 200 mg/kg. In conclusion, ethyl acetate extract of Z. zerumbet rhizome has a protective role against PCM-induced nephrotoxicity and the process is probably mediated through its antioxidant properties.
    Matched MeSH terms: Glutathione/metabolism
  13. Naidu KR, Kumar KS, Arulselvan P, Reddy CB, Lasekan O
    Arch Pharm (Weinheim), 2012 Dec;345(12):957-63.
    PMID: 23015406 DOI: 10.1002/ardp.201200192
    A series of α-hydroxyphosphonates were synthesized from the reaction of aldehyde (1) with triethylphosphite (2) in the presence of oxone and evaluated for their antioxidant properties against lipid peroxidation, reduced glutathione, superoxide dismutase, and catalase. The majority of the compounds showed promising antioxidant activity. Diethyl anthracen-9-yl (hydroxy) methylphosphonate (3n) is the most potent and biologically active compound against free radicals.
    Matched MeSH terms: Glutathione/metabolism
  14. Shakirin FH, Azlan A, Ismail A, Amom Z, Yuon LC
    Oxid Med Cell Longev, 2012;2012:840973.
    PMID: 22685623 DOI: 10.1155/2012/840973
    The aim of this paper was to compare the effects of pulp and kernel oils of Canarium odontophyllum Miq. (CO) on lipid profile, lipid peroxidation, and oxidative stress of healthy rabbits. The oils are rich in SFAs and MUFAs (mainly palmitic and oleic acids). The pulp oil is rich in polyphenols. Male New Zealand white (NZW) rabbits were fed for 4 weeks on a normal diet containing pulp (NP) or kernel oil (NK) of CO while corn oil was used as control (NC). Total cholesterol (TC), HDL-C, LDL-c and triglycerides (TG) levels were measured in this paper. Antioxidant enzymes (superoxide dismutase and glutathione peroxidise), thiobarbiturate reactive substances (TBARSs), and plasma total antioxidant status (TAS) were also evaluated. Supplementation of CO pulp oil resulted in favorable changes in blood lipid and lipid peroxidation (increased HDL-C, reduced LDL-C, TG, TBARS levels) with enhancement of SOD, GPx, and plasma TAS levels. Meanwhile, supplementation of kernel oil caused lowering of plasma TC and LDL-C as well as enhancement of SOD and TAS levels. These changes showed that oils of CO could be beneficial in improving lipid profile and antioxidant status as when using part of normal diet. The oils can be used as alternative to present vegetable oil.
    Matched MeSH terms: Glutathione Peroxidase/metabolism
  15. Nagamma T, Bhutia RD, Pokharel DR, Yadav S, Baxi J
    Asian Pac J Cancer Prev, 2012;13(7):3513-7.
    PMID: 22994787
    AIM: The present study assess the effect of consumption of alcohol on oxidative stress and antioxidant status in patients suffering from different types of cancer.

    METHODS: This hospital based case control study conducted in the Western part of Nepal covered a total of 93 cancer patients with or without alcohol intake and smoking habits, along with 94 age, sex and habit-matched individuals serving as controls. Plasma thiobarbituric acid reacting substances (TBARS), total antioxidant activity (TAA), vitamin C, α-tocopherol and erythrocyte reduced glutathione (GSH) were estimated and compared.

    RESULTS: The TBARS level was found to be significantly higher (p≤0.001) in all types of cancer patients when compared to controls, being aggravated in alcoholics with a smoking habit. No statistical significance (p≥0.05) was observed in the level of vitamin C and α-tocopherol. GSH and TAA level were significantly decreased (p≤0.001) in all the groups except those who consumed both branded as well as homemade alcohol and non-alcoholics without smoking habit.

    CONCLUSION: Alcohol, irrespective of its commercial brand, increases oxidative stress in all types of cancer patients. This is even higher when alcohol intake is combined with a smoking habit. Decreased TAA and GSH are major risk factors for cancer development.

    Matched MeSH terms: Glutathione/blood
  16. Kuppusamy UR, Tan JA
    West Indian Med J, 2011 Jan;60(1):3-8.
    PMID: 21809703
    Beta-thalassaemia major causes severe anaemia and patients with it may be transfusion-dependent for life. Regular blood transfusions cause iron-overload that leads to oxidative damage which can hasten mortality. The objective of this research was to study the oxidant-antioxidant indices in beta-thalassaemia major patients at the University of Malaya Medical Centre (UMMC) who were on desferrioxamine-chelation or without chelation therapy. Blood was collected from 39 Chinese patients and 20 controls. Plasma and peripheral blood mononuclear cell lysates (PBMC) were extracted and biochemical tests to evaluate oxidative stress were performed. Oxidative stress was evident in these patients as advanced oxidized protein products (AOPP) and lipid hydroperoxides were elevated, whereas glutathione peroxidase activity and the ferric reducing antioxidant power (FRAP) were reduced. The catalase activity in the patients' PBMC was elevated, possibly as a compensatory mechanism for the reduced glutathione peroxidase activity in both red blood cells and PBMC. The lower FRAP and higher AOPP levels in the non-chelated patients compared with the chelated patients were indicative of a lower oxidative stress level in the chelated patients. The ferritin levels in the chelated and non-chelated patients were high and the mean levels of liver enzyme activities in the majority of patients were elevated regardless of chelation therapy. In conclusion, this study indicates that desferrioxamine chelation therapy does not normalize ferritin level but attenuates oxidative damage and improves total antioxidant level in Malaysian Chinese beta-thalassaemia major patients.
    Matched MeSH terms: Glutathione Peroxidase/blood
  17. Ku CS, Teo SM, Naidoo N, Sim X, Teo YY, Pawitan Y, et al.
    J Hum Genet, 2011 Aug;56(8):552-60.
    PMID: 21677662 DOI: 10.1038/jhg.2011.54
    Copy number variations can be identified using newer genotyping arrays with higher single nucleotide polymorphisms (SNPs) density and copy number probes accompanied by newer algorithms. McCarroll et al. (2008) applied these to the HapMap II samples and identified 1316 copy number polymorphisms (CNPs). In our study, we applied the same approach to 859 samples from three Singapore populations and seven HapMap III populations. Approximately 50% of the 1291 autosomal CNPs were found to be polymorphic only in populations of non-African ancestry. Pairwise comparisons among the 10 populations showed substantial differences in the CNPs frequencies. Additionally, 698 CNPs showed significant differences with false discovery rate (FDR)<0.01 among the 10 populations and these loci overlap with known disease-associated or pharmacogenetic-related genes such as CFHR3 and CFHR1 (age related macular degeneration), GSTTI (metabolism of various carcinogenic compounds and cancers) and UGT2B17 (prostate cancer and graft-versus-host disease). The correlations between CNPs and genome-wide association studies-SNPs were investigated and several loci, which were previously unreported, that may potentially be implicated in complex diseases and traits were found; for example, childhood acute lymphoblastic leukaemia, age-related macular degeneration, breast cancer, response to antipsychotic treatment, rheumatoid arthritis and type-1 diabetes. Additionally, we also found 5014 novel copy number loci that have not been reported previously by McCarroll et al. (2008) in the 10 populations.
    Matched MeSH terms: Glutathione Transferase/genetics
  18. Haleagrahara N, Radhakrishnan A, Lee N, Kumar P
    Eur J Pharmacol, 2009 Oct 25;621(1-3):46-52.
    PMID: 19744476 DOI: 10.1016/j.ejphar.2009.08.030
    Quercetin is a bioflavonoid abundant in onions, apples, tea and red wine and one of the most studied flavonoids. Dietary quercetin intake is suggested to be health promoting, but this assumption is mainly based on mechanistic studies performed in vitro. The objective of this study was to investigate the effect of quercetin on stress-induced changes in oxidative biomarkers in the hypothalamus of rats. Adult male Sprague Dawley rats were subjected to forced swimming stress for 45 min daily for 14 days. Effect of quercetin at three different doses (10, 20 and 30 mg/kg body weight) on serum corticosterone and oxidative biomarkers (lipid hydroperoxides, antioxidant enzymes and total antioxidants) was estimated. Swimming stress significantly increased the serum corticosterone and lipid hydroperoxide levels. A significant decrease in total antioxidant levels and super oxide dismutase, glutathione peroxidase and catalase levels was seen in the hypothalamus after stress and treatment with quercetin significantly increased these oxidative parameters and there was a significant decrease in lipid hydroperoxide levels. These data demonstrate that forced swimming stress produced a severe oxidative damage in the hypothalamus and treatment with quercetin markedly attenuated these stress-induced changes. Antioxidant action of quercetin may be beneficial for the prevention and treatment of stress-induced oxidative damage in the brain.
    Matched MeSH terms: Glutathione Peroxidase/metabolism
  19. Maniam S, Mohamed N, Shuid AN, Soelaiman IN
    Basic Clin Pharmacol Toxicol, 2008 Jul;103(1):55-60.
    PMID: 18598299 DOI: 10.1111/j.1742-7843.2008.00241.x
    The aim of this study was to investigate the effects of vitamin E on the levels of lipid peroxidation and antioxidant enzymes in rat bones. Fifty-six normal male Sprague-Dawley rats, aged 3 months, were randomly divided into seven groups with eight rats in each group. The age-matched control group was given the vehicle olive oil, by oral gavage daily. Six of the treatment groups received either palm tocotrienol or pure alpha-tocopherol at the dose of 30, 60 or 100 mg/kg body weight, by oral gavage daily, 6 days a week for 4 months. Thiobarbituric acid-reactive substance (TBARS) that is an index to measure the level of lipid peroxidation and the antioxidant enzymes, glutathione peroxidase and superoxide dismutase levels were measured in the femur at the end of the study. Palm tocotrienol at the dose of 100 mg/kg body weight significantly reduced the TBARS level in the femur with a significant increase in glutathione peroxidase activity compared to the age-matched control group. These were not observed in the alpha-tocopherol groups. Palm tocotrienol was more effective than pure alpha-tocopherol acetate in suppressing lipid peroxidation in bone. Palm tocotrienol showed better protective effect against free radical damage in the femur compared to alpha-tocopherol. This study suggests that palm tocotrienol plays an important role in preventing imbalance in bone metabolism due to free radicals.
    Matched MeSH terms: Glutathione Peroxidase/metabolism
  20. Nafeeza MI, Kang TT
    Int J Vitam Nutr Res, 2005 Mar;75(2):149-55.
    PMID: 15929636
    Nonsteroidal anti-inflammatory drugs and their adverse effects on the gastric mucosa are yet another set of unresolved medical problems. This study examined the effects of various antioxidants on several gastric parameters after a single exposure to indomethacin. Forty-eight male rats of the Sprague-Dawley (200-250 g) strain were randomly divided to receive a single antioxidant (tocopherol, tocotrienol, or ubiquinone) or a combination of two (tocopherol-tocotrienol, tocopherol-ubiquinone or tocotrienol-ubiquinone) for 28 days. The rats were then challenged with a single dose of indomethacin and killed six hours later. Findings showed that the severity of gastric lesions was comparable in all groups. Only groups that received a combination of antioxidants exhibited reduced lipid peroxidation compared with all other groups (p < 0.05). The combination groups had a higher level of gastric prostaglandin E2 (PGE2) content compared with all other groups (p < 0.05). There was no significant difference among the groups in the gastric acid concentration and the glutathione/oxidized glutathione (GSH/GSSG) ratio. We conclude that although supplementation of these antioxidants in combination had desirable effects on lipid peroxidation and gastric PGE2 level, they did not reduce the lesions produced by indomethacin.
    Matched MeSH terms: Glutathione/analysis
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