Displaying publications 241 - 260 of 524 in total

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  1. Fulltext Antiglycation and Antioxidant Properties of Ficus deltoidea Varieties
    Mohd Dom NS, Yahaya N, Adam Z, Nik Abd Rahman NMA, Hamid M
    Evid Based Complement Alternat Med, 2020;2020:6374632.
    PMID: 32831872 DOI: 10.1155/2020/6374632
    The present study aimed to evaluate the potential of standardized methanolic extracts from seven Ficus deltoidea varieties in inhibiting the formation of AGEs, protein oxidation, and their antioxidant effects. The antiglycation activity was analyzed based on the inhibition of AGEs, fructosamine, and thiol groups level followed by the inhibition of protein carbonyl formation. The antioxidant activity (DPPH radical scavenging activity and reducing power assay) and total phenolic contents were evaluated. After 28 days of induction, all varieties of Ficus deltoidea extracts significantly restrained the formation of fluorescence AGEs by 4.55-5.14 fold. The extracts also reduced the fructosamine levels by 47.0-86.5%, increased the thiol group levels by 64.3-83.7%, and inhibited the formation of protein carbonyl by 1.36-1.76 fold. DPPH radical scavenging activity showed an IC50 value of 66.81-288.04 μg/ml and reducing power activity depicted at 0.02-0.24 μg/ml. The extent of phenolic compounds present in the extracts ranged from 70.90 to 299.78 mg·GAE/g. Apart from that, correlation studies between the activities were observed. This study revealed that seven varieties of Ficus deltoidea have the potential to inhibit AGEs formation and possess antioxidant activity that might be attributed to the presence of phenolic compounds.
    Matched MeSH terms: Oxidation-Reduction
  2. Fulltext Biogenic platinum from agricultural wastes extract for improved methanol oxidation reaction in direct methanol fuel cell
    Ishak NAIM, Kamarudin SK, Timmiati SN, Karim NA, Basri S
    J Adv Res, 2021 Feb;28:63-75.
    PMID: 33364046 DOI: 10.1016/j.jare.2020.06.025
    Platinum is the most commonly used catalyst in fuel cell application. However, platinum is very expensive, thus limits the commercialisation of fuel cell system due to the cost factor. This study introduces a biosynthesis platinum from plant extracts that can reduce the cost of platinum production compared to the conventional method and the hazardous during the production of the catalyst. The biogenic platinum was tested on a Direct Methanol Fuel Cell. Advanced biogenic of Pt nano-cluster was synthesized through a novel and facile of one-pot synthesis bio-reduction derived from natural source in the form of plant extracts as reducing agent. Several selected plant extracts drawn from agricultural waste such as banana peel, pineapple peels and sugarcane bagasse extracts were comparatively evaluated on the ability of phytochemical sources of polyphenols rich for the development of single-step synthesis for Pt NPs. Notably, the biogenic Pt NPs from sugar cane bagasse has superior electro-catalytic activity, the enhanced utilization efficiency of Pt and appreciable stability towards methanol oxidation reaction, whose ECSA value approximates 94.58 m2g-1, mass activity/specific activity (398.20 mAmg-1/0.8471 mA/cm2Pt) which greater than commercial Pt black (158.12 mAmg-1/1.41 mA/cm2Pt).
    Matched MeSH terms: Oxidation-Reduction
  3. Fulltext Expression of the Arabidopsis redox-related LEA protein, SAG21 is regulated by ERF, NAC and WRKY transcription factors
    Evans KV, Ransom E, Nayakoti S, Wilding B, Mohd Salleh F, Gržina I, et al.
    Sci Rep, 2024 Apr 02;14(1):7756.
    PMID: 38565965 DOI: 10.1038/s41598-024-58161-0
    SAG21/LEA5 is an unusual late embryogenesis abundant protein in Arabidopsis thaliana, that is primarily mitochondrially located and may be important in regulating translation in both chloroplasts and mitochondria. SAG21 expression is regulated by a plethora of abiotic and biotic stresses and plant growth regulators indicating a complex regulatory network. To identify key transcription factors regulating SAG21 expression, yeast-1-hybrid screens were used to identify transcription factors that bind the 1685 bp upstream of the SAG21 translational start site. Thirty-three transcription factors from nine different families bound to the SAG21 promoter, including members of the ERF, WRKY and NAC families. Key binding sites for both NAC and WRKY transcription factors were tested through site directed mutagenesis indicating the presence of cryptic binding sites for both these transcription factor families. Co-expression in protoplasts confirmed the activation of SAG21 by WRKY63/ABO3, and SAG21 upregulation elicited by oligogalacturonide elicitors was partially dependent on WRKY63, indicating its role in SAG21 pathogen responses. SAG21 upregulation by ethylene was abolished in the erf1 mutant, while wound-induced SAG21 expression was abolished in anac71 mutants, indicating SAG21 expression can be regulated by several distinct transcription factors depending on the stress condition.
    Matched MeSH terms: Oxidation-Reduction
  4. Fulltext Tetrahydroxanthene-1,3(2H)-diones and Oxidized Hexadiene Derivatives from Uvaria leptopoda and Their Biological Activities
    Teerapongpisan P, Monkantha T, Yimklan S, Mah SH, Gunter NV, Promnart P, et al.
    J Nat Prod, 2024 Jun 28;87(6):1611-1617.
    PMID: 38805684 DOI: 10.1021/acs.jnatprod.4c00248
    The first phytochemical investigation of the twig extract of Uvaria leptopoda resulted in the isolation and identification of three new tetrahydroxanthene-1,3(2H)-diones, uvarialeptones A-C, two new oxidized hexadiene derivatives, uvarialeptols A and B, together with ten known compounds. Their structures were elucidated by spectroscopic techniques and mass spectrometry. Uvarialeptones A and B were unprecedented tetrahydroxanthene-1,3(2H)-dione dimers which exhibited a cyclobutane ring via [2 + 2] cycloaddition from uvarialeptone C and 9a-O-methyloxymitrone, respectively. The structure of uvarialeptone A was confirmed by X-ray diffraction analysis using Mo Kα radiation. Compound 3 inhibited NO production at an IC50 value of 6.7 ± 0.1 μM.
    Matched MeSH terms: Oxidation-Reduction
  5. Fulltext Metabolomics Profiling on Different Stages of Colorectal Cancer: A Systematic Review
    Yusof HM, Ab-Rahim S, Suddin LS, Saman MSA, Mazlan M
    Malays J Med Sci, 2018 Sep;25(5):16-34.
    PMID: 30914860 MyJurnal DOI: 10.21315/mjms2018.25.5.3
    Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. Early diagnosis and accurate staging of the disease is vital to improve the prognosis. Metabolomics has been used to identify changes in metabolite profiles in the different stages of cancer in order to introduce new non-invasive molecular tools for staging. In this systematic review, we aim to identify the common metabolite changes in human biological samples and the dominant metabolic pathways associated with CRC progression. A broad systematic search was carried out from selected databases. Four reviewers screened and reviewed the titles, abstracts, and full-text articles according to the inclusion and exclusion criteria. Quality assessment was conducted on the eight articles which met the criteria. Data showed that the metabolites involved with redox status, energy metabolism and intermediates of amino acids, choline and nucleotides metabolism were the most affected during CRC progression. However, there were differences in the levels of individual metabolites detected between the studies, and this might be due to the study population, sample preparation, analytical platforms used and statistical tools. In conclusion, this systematic review highlights the changes in metabolites from early to late stages of CRC. Moreover, biomarkers for prognosis are important to reduce CRC-related mortality.
    Matched MeSH terms: Oxidation-Reduction
  6. Functionality enhancement of pea protein isolate through cold plasma modification for 3D printing application
    Liu Y, Sun J, Wen Z, Wang J, Roopesh MS, Pan D, et al.
    Food Res Int, 2024 Dec;197(Pt 1):115267.
    PMID: 39593346 DOI: 10.1016/j.foodres.2024.115267
    Pea protein isolate (PPI) is a valued sustainable protein source, but its relatively poor functional properties limit its applications. This study reports on the effects of cold argon plasma (CP) treatment of a 15 % (w/w) PPI solution on the functionality, structure, and oxidative characteristics of PPI, as well as its application in 3D-printed plant-based meat. Results indicate that hydroxyl radicals and high-energy excited-state argon atoms are the primary active substances. A decrease in free sulfhydryl content and an increase in carbonyl content were observed in treated PPI, indicating oxidative modification. Compared to the control group, the gel strength of PPI was increased by 62.5 % and the storage modulus was significantly improved after 6 min treatment, forming a more ordered and highly cross-linked 3D gel network. Additionally, CP significantly improved the water-holding capacity, oil-holding capacity, emulsifying activity, and emulsion stability of PPI. The α-helix and random coil content in PPI decreased, while the β-sheet content increased, resulting in a more ordered secondary structure after CP treatment. Compared to untreated PPI, the consistency coefficient (K) increased from 36.00 to 47.68 Pa·sn. The treated PPI exhibited higher apparent viscosity and storage modulus and demonstrated better 3D printing performance and self-supporting ability. This study demonstrates that CP can significantly enhance the functional properties of PPI, providing great potential and prospects for improving the printability of 3D printing materials and developing plant protein foods with low-allergenicity.
    Matched MeSH terms: Oxidation-Reduction
  7. Fulltext Interaction between vitamin E and glutathione in rat brain: Effect of chronic ethanol administration
    Marcus SR, Chandrakala MV, Nadiger HA
    Asia Pac J Clin Nutr, 1998 Dec;7(3/4):201-5.
    PMID: 24393672
    The protection against ethanol-induced lipid peroxidation is rendered by antioxidants such as vitamin E and glutathione (GSH) interacting with each other and also functioning independently. A study of the levels of GSH and activities of glutathione peroxidase (GP), glutathione reductase (GR) and glutathione transferase (GST) in the cerebral cortex (CC), cerebellum (CB) and brain stem (BS) of vitamin E-supplemented and -deficient rats subjected to ethanol administration for 30 days was carried out. Chronic ethanol administration to vitamin E-supplemented rats elevated GP, GR and GST activities in the three regions and GSH levels in the CB. Chronic ethanol administration to vitamin E-deficient rats elevated GR activity in the three regions and GP activity in the CC and CB, decreased GST activity in the CC and CB, but did not alter GSH levels compared with normal rats subjected to chronic ethanol administration. The results indicate that vitamin E helps to maintain GSH levels to combat increased peroxidation while its absence has a deleterious effect.
    Matched MeSH terms: Oxidation-Reduction
  8. Fulltext Antioxidant activity characterization, phytochemical screening, and proximate analysis of Cermela Hutan (Phyllanthus gomphocarpus Hook. F) roots and leaves
    Bahari EA, Zaaba NE, Haron N, Dasiman R, Amom Z
    Med Sci Monit Basic Res, 2014;20:170-5.
    PMID: 25381551 DOI: 10.12659/MSMBR.892345
    Roots and leaves of the Cermela Hutan (Phyllanthus gomphocarpus Hook. F) plant were studied to determine antioxidant activity, phytochemical compounds, proportion of carbohydrate, crude protein, moisture, ash, fat, total phenolic content (TPC), and total flavonoid content (TFC).
    Matched MeSH terms: Oxidation-Reduction/drug effects
  9. Fulltext Increased basal oxidation of peroxiredoxin 2 and limited peroxiredoxin recycling in glucose-6-phosphate dehydrogenase-deficient erythrocytes from newborn infants
    Cheah FC, Peskin AV, Wong FL, Ithnin A, Othman A, Winterbourn CC
    FASEB J, 2014 Jul;28(7):3205-10.
    PMID: 24636884 DOI: 10.1096/fj.14-250050
    Erythrocytes require glucose-6-phosphate dehydrogenase (G6PD) to generate NADPH and protect themselves against hemolytic anemia induced by oxidative stress. Peroxiredoxin 2 (Prx2) is a major antioxidant enzyme that requires NADPH to recycle its oxidized (disulfide-bonded) form. Our aims were to determine whether Prx2 is more highly oxidized in G6PD-deficient erythrocytes and whether these cells are able to recycle oxidized Prx2 after oxidant challenge. Blood was obtained from 61 Malaysian neonates with G6PD deficiency (average 33% normal activity) and 86 controls. Prx2 redox state was analyzed by Western blotting under nonreducing conditions. Prx2 in freshly isolated blood was predominantly reduced in both groups, but the median level of oxidation was significantly higher (8 vs 3%) and the range greater for the G6PD-deficient population. When treated with reagent H2O2, the G6PD-deficient erythrocytes were severely compromised in their ability to recycle oxidized Prx2, with only 27 or 4% reduction after 1 h treatment with 0.1 or 1 mM H2O2 respectively, compared with >97% reduction in control erythrocytes. The accumulation of oxidized Prx2 in oxidatively stressed erythrocytes with common G6PD variants suggests that impaired antioxidant activity of Prx2 could contribute to the hemolysis and other complications associated with the condition.-Cheah, F.-C., Peskin, A. V., Wong, F.-L., Ithnin, A., Othman, A., Winterbourn, C. C. Increased basal oxidation of peroxiredoxin 2 and limited peroxiredoxin recycling in glucose-6-phosphate dehydrogenase deficient erythrocytes from newborn infants.
    Matched MeSH terms: Oxidation-Reduction/drug effects
  10. Fulltext Effects of acute gamma irradiation on physiological traits and flavonoid accumulation of Centella asiatica
    Moghaddam SS, Jaafar H, Ibrahim R, Rahmat A, Aziz MA, Philip E
    Molecules, 2011 Jun 17;16(6):4994-5007.
    PMID: 21694666 DOI: 10.3390/molecules16064994
    In the present study, two accessions of Centella asiatica (CA03 and CA23) were subjected to gamma radiation to examine the response of these accessions in terms of survival rate, flavonoid contents, leaf gas exchange and leaf mass. Radiation Sensitivity Tests revealed that based on the survival rate, the LD(50) (gamma doses that killed 50% of the plantlets) of the plantlets were achieved at 60 Gy for CA03 and 40 Gy for CA23. The nodal segments were irradiated with gamma rays at does of 30 and 40 Gy for Centella asiatica accession 'CA03' and 20 and 30 Gy for accession 'CA23. The nodal segment response to the radiation was evaluated by recording the flavonoid content, leaf gas exchange and leaf biomass. The experiment was designed as RCBD with five replications. Results demonstrated that the irradiated plantlets exhibited greater total flavonoid contents (in eight weeks) significantly than the control where the control also exhibited the highest total flavonoid contents in the sixth week of growth; 2.64 ± 0.02 mg/g DW in CA03 and 8.94 ± 0.04 mg/g DW in CA23. The total flavonoid content was found to be highest after eight weeks of growth, and this, accordingly, stands as the best time for leaf harvest. Biochemical differentiation based on total flavonoid content revealed that irradiated plantlets in CA23 at 20 and 30 Gy after eight weeks contained the highest total flavonoid concentrations (16.827 ± 0.02; 16.837 ± 0.008 mg/g DW, respectively) whereas in CA03 exposed to 30 and 40 Gy was found to have the lowest total flavonid content (5.83 ± 0.11; 5.75 ± 0.03 mg/g DW). Based on the results gathered in this study, significant differences were found between irradiated accessions and control ones in relation to the leaf gas. The highest PN and gs were detected in CA23 as control followed by CA23 irradiated to 20Gy (CA23G20) and CA23G30 and the lowest PN and gs were observed in CA03 irradiated to 40Gy (CA03G40). Moreover, there were no significant differences in terms of PN and gs among the irradiated plants in each accession. The WUE of both irradiated accessions of Centella asiatica were reduced as compared with the control plants (p < 0.01) while Ci and E were enhanced. There were no significant differences in the gas exchange parameters among radiated plants in each accession. Moreover, malondialdehyde (MDA) of accessions after gamma treatments were significantly higher than the control, however, flavonoids which were higher concentration in irradiated plants can scavenge surplus free radicals. Therefore, the findings of this study have proven an efficient method of in vitro mutagenesis through gamma radiation based on the pharmaceutical demand to create economically superior mutants of C. asiatica. In other words, the results of this study suggest that gamma irradiation on C. asiatica can produce mutants of agricultural and economical importance.
    Matched MeSH terms: Oxidation-Reduction/radiation effects
  11. A kinetic study of autohydrogenotrophic denitrification at the optimum pH and sodium bicarbonate dose
    Ghafari S, Hasan M, Aroua MK
    Bioresour Technol, 2010 Apr;101(7):2236-42.
    PMID: 20015639 DOI: 10.1016/j.biortech.2009.11.068
    In this study the kinetics of autohydrogenotrophic denitrification was studied under optimum solution pH and bicarbonate concentration. The optimal pH and bicarbonate concentration were firstly obtained using a design of experiment (DOE) methodology. For this purpose a total of 11 experiments were carried out. Sodium bicarbonate concentrations ranging of 20-2000 mg/L and pH values from 6.5 to 8.5 were used in the optimization runs. It was found that the pH has a more pronounced effect on the denitrification process as compared to the bicarbonate dose. The developed quadratic model predicted the optimum conditions at pH 8 and 1100 mg NaHCO(3)/L. Using these optimal conditions, the kinetics of denitrification for nitrate and nitrite degradation were investigated in separate experiments. Both processes were found to follow a zero order kinetic model. The ultimate specific degradation rates for nitrate and nitrite remediation were 29.60 mg NO(3)(-)-N/g MLVSS/L and 34.85 mg NO(3)(-)-N/g MLVSS/L respectively, when hydrogen was supplied every 0.5h.
    Matched MeSH terms: Oxidation-Reduction/drug effects
  12. Hexavalent molybdenum reduction to molybdenum blue by S. marcescens strain Dr. Y6
    Shukor MY, Habib SH, Rahman MF, Jirangon H, Abdullah MP, Shamaan NA, et al.
    Appl Biochem Biotechnol, 2008 Apr;149(1):33-43.
    PMID: 18350385 DOI: 10.1007/s12010-008-8137-z
    A molybdate-reducing bacterium has been locally isolated. The bacterium reduces molybdate or Mo(6+) to molybdenum blue (molybdate oxidation states of between 5+ and 6+). Different carbon sources such as acetate, formate, glycerol, citric acid, lactose, fructose, glucose, mannitol, tartarate, maltose, sucrose, and starch were used at an initial concentration of 0.2% (w/v) in low phosphate media to study their effect on the molybdate reduction efficiency of bacterium. All of the carbon sources supported cellular growth, but only sucrose, maltose, glucose, and glycerol (in decreasing order) supported molybdate reduction after 24 h of incubation. Optimum concentration of sucrose for molybdate reduction is 1.0% (w/v) after 24 h of static incubation. Ammonium sulfate, ammonium chloride, valine, OH-proline, glutamic acid, and alanine (in the order of decreasing efficiency) supported molybdate reduction with ammonium sulfate giving the highest amount of molybdenum blue after 24 h of incubation at 0.3% (w/v). The optimum molybdate concentration that supports molybdate reduction is between 15 and 25 mM. Molybdate reduction is optimum at 35 degrees C. Phosphate at concentrations higher than 5 mM strongly inhibits molybdate reduction. The molybdenum blue produced from cellular reduction exhibits a unique absorption spectrum with a maximum peak at 865 nm and a shoulder at 700 nm. The isolate was tentatively identified as Serratia marcescens Strain Dr.Y6 based on carbon utilization profiles using Biolog GN plates and partial 16s rDNA molecular phylogeny.
    Matched MeSH terms: Oxidation-Reduction/drug effects
  13. Fulltext Free radical scavenging potential of Lagenaria siceraria (Molina) Standl fruits extract
    Mayakrishnan V, Veluswamy S, Sundaram KS, Kannappan P, Abdullah N
    Asian Pac J Trop Med, 2013 Jan;6(1):20-6.
    PMID: 23317881 DOI: 10.1016/S1995-7645(12)60195-3
    OBJECTIVE: To elucidate free radical scavenging activity of ethanolic extract Lagenaria siceraria (L. siceraria) (Molina) fruit.

    METHODS: The free radical scavenging activity of the L. siceraria (Molina) fruit extract was assayed by using α,α-diphenyl-β-picrylhydrazyl (DPPH), 2,20-azinobis 3-ethyl benzothiazoline-6-sulfonate (ABTS), FRAP, reducing power, chelating ability and β-carotene bleaching assay.

    RESULTS: The IC(50) values of DPPH and ABTS radical-scavenging activity was found to be 1.95 mg/mL and 19 mg/mL, respectively. In ferrous chelation assay, the percentage of inhibition was found to be 89.21%. The reducing power of ethanolic extract of L. siceraria (Molina) fruit was 0.068 at 1 mg/mL and increased to 0.192 at 5 mg/mL. The β-carotene linoleate bleaching assay was 46.7% at 5 mg/mL and antioxidant activity using FRAP at 0.305 for 1 mg/mL to 0.969 for 5 mg/mL.

    CONCLUSIONS: The results indicate that L. siceraria (Molina) fruit could be an important sources of natural radical scavengers.

    Matched MeSH terms: Oxidation-Reduction/drug effects
  14. Peroxiredoxin of Arthrospira platensis derived short molecule YT12 influences antioxidant and anticancer activity
    Sannasimuthu A, Ramani M, Pasupuleti M, Saraswathi NT, Arasu MV, Al-Dhabi NA, et al.
    Cell Biol Int, 2020 Nov;44(11):2231-2242.
    PMID: 32716104 DOI: 10.1002/cbin.11431
    This study demonstrates both the antioxidant and anticancer potential of the novel short molecule YT12 derived from peroxiredoxin (Prx) of spirulina, Arthrospira platensis (Ap). ApPrx showed significant reduction in reactive oxygen species (ROS) against hydrogen peroxide (H2 O2 ) stress. The complementary DNA sequence of ApPrx contained 706 nucleotides and its coding region possessed 546 nucleotides between position 115 and 660. Real-time quantitative reverse transcription polymerase chain reaction analysis confirmed the messenger RNA expression of ApPrx due to H2 O2 exposure in spirulina cells at regular intervals, in which the highest expression was noticed on Day 20. Cytotoxicity assay was performed using human peripheral blood mononuclear cells, and revealed that at 10 μM, the YT12 did not exhibit any notable toxicity. Furthermore, ROS scavenging activity of YT12 was performed using DCF-DA assay, in which YT12 scavenged a significant amount of ROS at 25 μM in H2 O2 -treated blood leukocytes. The intracellular ROS in human colon adenocarcinoma cells (HT-29) was regulated by oxidative stress, where the YT12 scavenges ROS in HT-29 cells at 12.5 μM. Findings show that YT12 peptide has anticancer activity, when treated against HT-29 cells. Through the MTT assay, YT12 showed vital cytotoxicity against HT-29 cells. These finding suggested that YT12 is a potent antioxidant molecule which defends ROS against oxidative stress and plays a role in redox balance.
    Matched MeSH terms: Oxidation-Reduction/drug effects
  15. Improved isolated heart contractility and mitochondrial oxidation after chronic treatment with Panax ginseng in rats
    Toh HT
    Am J Chin Med, 1994;22(3-4):275-84.
    PMID: 7872239
    Heart mitochondria freshly isolated from ginseng treated rats respired higher at ADP-induced, state 3 respiratory rates and with greater respiratory indices. These mitochondria were less susceptible to experimentally-induced functional impairment. Control heart mitochondria incubated with ginseng extract also showed that ginseng prevented mitochondria from incubation induced deterioration with NAD-linked substrates. Comparison of force of contraction of isolated, perfused and electrically paced hearts showed that deterioration of the force of heart contraction was consistently smaller throughout the experiment in hearts from ginseng treated rats. These results indicated that Panax ginseng was able to delay experimentally induced heart mitochondrial impairment and muscle contraction deterioration.
    Matched MeSH terms: Oxidation-Reduction/drug effects
  16. Antioxidative and Inhibitory Effects of the Fruiting Body of Black Lingzhi Mushroom, Amauroderma rugosum (Agaricomycetes), on LDL Oxidation and HMG-CoA Reductase Activity
    Seng CK, Abdullah N, Aminudin N
    Int J Med Mushrooms, 2017;19(9):797-807.
    PMID: 29199554 DOI: 10.1615/IntJMedMushrooms.2017024374
    Amauroderma rugosum fruiting bodies possess excellent cardiovascular benefits, including antioxidative, antihyperlipidemic, antihypertensive, antiinflammatory, anti-platelet aggregation, and antithrombotic effects. In this article, we describe our investigations of the in vitro antioxidant activity and in vitro antiatherosclerotic potential through inhibitory effects on low-density lipoprotein (LDL), LDL peroxidation, and 3-hydroxy3-methylglutaryl-coenzyme A (HMG-CoA) reductase catalytic activity using various fruiting body extracts partitioned with an organic solvent. Among 5 extracts/fractions tested, the semipolar ethyl acetate (EA) fraction demonstrated good antioxidant capacity based on total phenolic content, 2,2-diphenyl-1-picrylhydrazyl free radical scavenging, ferrous ion-chelating ability, cupric ion-reducing antioxidant capacity, and lipid peroxidation assays. The EA fraction also showed the strongest inhibitory effect on Cu2+-induced LDL oxidation via thiobarbituric acid reactive substances formation and HMG-CoA reductase activity. Chemical analysis conjointly identified 10 phenolic compounds (4 benzoic acid derivatives, 3 flavonoids, 1 cinnamic acid, 1 hexahydroxydiphenic acid dilactone, and 1 xanthone derivative), some of which play pivotal roles in arresting the physiopathogenesis of atherosclerosis, thereby attenuating the risk of cardiovascular events occurring.
    Matched MeSH terms: Oxidation-Reduction/drug effects
  17. Fulltext Benzofuranyl Esters: Synthesis, Crystal Structure Determination, Antimicrobial and Antioxidant Activities
    Kumar CS, Then LY, Chia TS, Chandraju S, Win YF, Sulaiman SF, et al.
    Molecules, 2015 Sep 11;20(9):16566-81.
    PMID: 26378514 DOI: 10.3390/molecules200916566
    A series of five new 2-(1-benzofuran-2-yl)-2-oxoethyl 4-(un/substituted)benzoates 4(a-e), with the general formula of C₈H₅O(C=O)CH₂O(C=O)C₆H₄X, X = H, Cl, CH₃, OCH₃ or NO₂, was synthesized in high purity and good yield under mild conditions. The synthesized products 4(a-e) were characterized by FTIR, ¹H-, (13)C- and ¹H-(13)C HMQC NMR spectroscopic analysis and their 3D structures were confirmed by single-crystal X-ray diffraction studies. These compounds were screened for their antimicrobial and antioxidant activities. The tested compounds showed antimicrobial ability in the order of 4b < 4a < 4c < 4d < 4e and the highest potency with minimum inhibition concentration (MIC) value of 125 µg/mL was observed for 4e. The results of antioxidant activities revealed the highest activity for compound 4e (32.62% ± 1.34%) in diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, 4d (31.01% ± 4.35%) in ferric reducing antioxidant power (FRAP) assay and 4a (27.11% ± 1.06%) in metal chelating (MC) activity.
    Matched MeSH terms: Oxidation-Reduction/drug effects
  18. Fulltext Effect of the tocotrienol-rich fraction on the lifespan and oxidative biomarkers in Caenorhabditis elegans under oxidative stress
    Aan GJ, Zainudin MS, Karim NA, Ngah WZ
    Clinics (Sao Paulo), 2013 May;68(5):599-604.
    PMID: 23778402 DOI: 10.6061/clinics/2013(05)04
    OBJECTIVE: This study was performed to determine the effect of the tocotrienol-rich fraction on the lifespan and oxidative status of C. elegans under oxidative stress.

    METHOD: Lifespan was determined by counting the number of surviving nematodes daily under a dissecting microscope after treatment with hydrogen peroxide and the tocotrienol-rich fraction. The evaluated oxidative markers included lipofuscin, which was measured using a fluorescent microscope, and protein carbonyl and 8-hydroxy-2'-deoxyguanosine, which were measured using commercially available kits.

    RESULTS: Hydrogen peroxide-induced oxidative stress significantly decreased the mean lifespan of C. elegans, which was restored to that of the control by the tocotrienol-rich fraction when administered before or both before and after the hydrogen peroxide. The accumulation of the age marker lipofuscin, which increased with hydrogen peroxide exposure, was decreased with upon treatment with the tocotrienol-rich fraction (p<0.05). The level of 8-hydroxy-2'-deoxyguanosine significantly increased in the hydrogen peroxide-induced group relative to the control. Treatment with the tocotrienol-rich fraction before or after hydrogen peroxide induction also increased the level of 8-hydroxy-2'-deoxyguanosine relative to the control. However, neither hydrogen peroxide nor the tocotrienol-rich fraction treatment affected the protein carbonyl content of the nematodes.

    CONCLUSION: The tocotrienol-rich fraction restored the lifespan of oxidative stress-induced C. elegans and reduced the accumulation of lipofuscin but did not affect protein damage. In addition, DNA oxidation was increased.

    Matched MeSH terms: Oxidation-Reduction/drug effects
  19. Fulltext Antioxidant Activities of 4-Methylumbelliferone Derivatives
    Al-Majedy YK, Al-Amiery AA, Kadhum AA, Mohamad AB
    PLoS One, 2016;11(5):e0156625.
    PMID: 27243231 DOI: 10.1371/journal.pone.0156625
    The synthesis of derivatives of 4-Methylumbelliferone (4-MUs), which are structurally interesting antioxidants, was performed in this study. The modification of 4-Methylumbelliferone (4-MU) by different reaction steps was performed to yield the target compounds, the 4-MUs. The 4-MUs were characterized by different spectroscopic techniques (Fourier transform infrared; FT-IR and Nuclear magnetic resonance; NMR) and micro-elemental analysis (CHNS). The in vitro antioxidant activity of the 4-MUs was evaluated in terms of their free radical scavenging activities against 2,2-diphenyl-1-picrylhydrazyl (DPPH), Nitric oxide radical scavenging activity assay, chelating activity and their (FRAP) ferric-reducing antioxidant power, which were compared with a standard antioxidant. Our results reveal that the 4-MUs exhibit excellent radical scavenging activities. The antioxidant mechanisms of the 4-MUs were also studied. Density Function Theory (DFT)-based quantum chemical studies were performed with the basis set at 3-21G. Molecular models of the synthesized compounds were studied to understand the antioxidant activity. The electron levels, namely HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital), for these synthesized antioxidants were also studied.
    Matched MeSH terms: Oxidation-Reduction/drug effects
  20. Fulltext Photocatalysis and photoelectrochemical properties of tungsten trioxide nanostructured films
    Lai CW
    ScientificWorldJournal, 2014;2014:843587.
    PMID: 24782669 DOI: 10.1155/2014/843587
    Tungsten trioxide (WO₃) possesses a small band gap energy of 2.4-2.8 eV and is responsive to both ultraviolet and visible light irradiation including strong absorption of the solar spectrum and stable physicochemical properties. Thus, controlled growth of one-dimensional (1D) WO₃ nanotubular structures with desired length, diameter, and wall thickness has gained significant interest. In the present study, 1D WO₃ nanotubes were successfully synthesized via electrochemical anodization of tungsten (W) foil in an electrolyte composed of 1 M of sodium sulphate (Na₂SO₄) and ammonium fluoride (NH₄F). The influence of NH₄F content on the formation mechanism of anodic WO₃ nanotubular structure was investigated in detail. An optimization of fluoride ions played a critical role in controlling the chemical dissolution reaction in the interface of W/WO₃. Based on the results obtained, a minimum of 0.7 wt% of NH₄F content was required for completing transformation from W foil to WO₃ nanotubular structure with an average diameter of 85 nm and length of 250 nm within 15 min of anodization time. In this case, high aspect ratio of WO₃ nanotubular structure is preferred because larger active surface area will be provided for better photocatalytic and photoelectrochemical (PEC) reactions.
    Matched MeSH terms: Oxidation-Reduction/radiation effects
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