Displaying publications 41 - 60 of 134 in total

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  1. Fulltext Effects of Payena dasyphylla (Miq.) on hyaluronidase enzyme activity and metalloproteinases protein expressions in interleukin-1β stimulated human chondrocytes cells
    Citalingam K, Zareen S, Shaari K, Ahmad S
    BMC Complement Altern Med, 2013 Aug 23;13:213.
    PMID: 23971790 DOI: 10.1186/1472-6882-13-213
    BACKGROUND: Hyaluronidases have been found as the target enzymes in the development of osteoarthritis (OA) disease. While there is still no curative treatment for this disease, recent studies on the treatment of OA were focused on the effectiveness of natural products which are expected to improve the symptoms with minimal side effects. The aim of this study was to screen selected Malaysian plants on their anti-hyaluronidase activity as well as to evaluate the active plant and its derived fractions on its potential anti-arthritic and antioxidant activities.

    METHODS: A total of 20 methanolic crude extracts (bark and leaf) from ten different plants were screened using a colorimetric hyaluronidase enzymatic assay. The active plant extract (Payena dasyphylla) was then studied for its hyaluronidase inhibitory activity in the interleukin-1β (IL-1β) stimulated human chondrocytes cell line (NHAC-kn) using zymography method. The Payena dasyphylla methanolic bark extract was then fractionated into several fractions in where the ethyl acetate (EA) fraction was evaluated for its inhibitory effects on the HYAL1 and HYAL2 gene expressions using reverse transcription-polymerase chain reaction (RT-PCR) technique. While the MMP-3 and MMP-13 protein expressions were evaluated using western blot method. The phenolic and flavonoid contents of the three fractions as well as the antioxidant property of the EA fraction were also evaluated.

    RESULTS: Bark extract of Payena dasyphylla (100 μg/ml) showed the highest inhibitory activity against bovine testicular hyaluronidase with 91.63%. The plant extract also inhibited hyaluronidase expression in the cultured human chondrocyte cells in response to IL-1β (100 ng/ml). Similarly, treatment with Payena dasyphylla ethyl acetate (EA) fraction (100 μg/ml) inhibited the HYAL1 and HYAL2 mRNA gene expressions as well as MMP-3 and MMP-13 protein expression in a dose dependent manner. Payena dasyphylla EA fraction has demonstrated the highest amount of phenolic and flavonoid content with 168.62 ± 10.93 mg GAE/g and 95.96 ± 2.96 mg RE/g respectively as compared to water and hexane fractions. In addition, the Payena dasyphylla EA fraction showed strong antioxidant activity with IC₅₀ value of 11.64 ± 1.69 μg/mL.

    CONCLUSION: These findings have shown that Payena dasyphylla might contained potential phenolic compounds that inhibiting the key enzyme in osteoarthritis development, which is the hyaluronidase enzyme through interruption of HYAL1 and HYAL1 gene expressions. The degradation of cartilage could also be inhibited by the plant through suppression of MMP-3 and MMP-13 protein expressions. We also reported that the inhibitory effect of Payena dasyphylla on hyaluronidase activity and expression might be due to its anti-oxidant property.

    Matched MeSH terms: Acetates
  2. Fulltext Effects of extraction time on the functional properties of silver catfish (Pangasius sutchi) skin gelatin
    Normah Ismail, Najihah Shukor, Zainal Samicho
    Scientific Research Journal, 2013;10(1):0-0.
    MyJurnal
    Silver catfish (Pangasius sutchi) skin gelatin was extracted to determine the effects of extraction time on the functional properties of the gelatin in terms of solubility, protein solubility as a function of pH and sodium chloride concentration, emulsifying capacity and stability, water holding capacity, fat binding capacities and foaming properties. Silver catfish skins were washed in sodium chloride (NaCl) solution prior to pre-treatment in sodium hydroxide (NaOH) and acetic acid solution. Gelatin was extracted at 50ºC for 6, 8, 10 and 12 hours extraction time followed by freeze drying. The extraction of silver catfish skin gelatin at 50 ºC for 12 hours was more effective than extraction at 6, 8 and 10 hours where the gelatin was characterized by higher emulsifying capacity (52.63%), emulsifying stability (47.83%), water holding capacity (31.78 mL/g), fat binding capacities (54.76%), foaming capacity (41.47 mL) and foaming stability (56.42%) than gelatins extracted at other extraction time. The longer the extraction time, the better the functional properties of the gelatin. Based on its good functional properties, silver catfish skin gelatin may be useful in various food applications such as soups, sauces and gravies.
    Matched MeSH terms: Acetates
  3. Fulltext Amauroderma rugosum (Blume & T. Nees) Torrend: Nutritional Composition and Antioxidant and Potential Anti-Inflammatory Properties
    Chan PM, Kanagasabapathy G, Tan YS, Sabaratnam V, Kuppusamy UR
    Evid Based Complement Alternat Med, 2013;2013:304713.
    PMID: 24371454 DOI: 10.1155/2013/304713
    Amauroderma rugosum is a wild mushroom that is worn as a necklace by the indigenous communities in Malaysia to prevent fits and incessant crying by babies. The aim of this study was to investigate the nutritive composition and antioxidant potential and anti-inflammatory effects of A. rugosum extracts on LPS-stimulated RAW264.7 cells. Nutritional analysis of freeze-dried mycelia of A. rugosum (KUM 61131) from submerged culture indicated a predominant presence of carbohydrates, proteins, dietary fibre, phosphorus, potassium, and sodium. The ethanol crude extract (EE), its hexane (HF), ethyl acetate (EAF), and aqueous (AF) fractions of mycelia of A. rugosum grown in submerged culture were evaluated for antioxidant potential and anti-inflammatory effects. EAF exhibited the highest total phenolic content and the strongest antioxidant activity based on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays. HF showed dose-dependent inhibition of NO production in LPS-stimulated RAW264.7 cells and NO radical scavenging activity. Gas chromatographic analysis of HF revealed the presence of ethyl linoleate and ergosterol, compounds with known anti-inflammatory properties. In conclusion, the nutritive compositions and significant antioxidant potential and anti-inflammatory effects of mycelia extracts of A. rugosum have the potential to serve as a therapeutic agent or adjuvant in the management of inflammatory disorders.
    Matched MeSH terms: Acetates
  4. Fulltext Antioxidant Capacity, Cytotoxicity, and Acute Oral Toxicity of Gynura bicolor
    Teoh WY, Sim KS, Moses Richardson JS, Abdul Wahab N, Hoe SZ
    Evid Based Complement Alternat Med, 2013;2013:958407.
    PMID: 24369485 DOI: 10.1155/2013/958407
    Gynura bicolor (Compositae) which is widely used by the locals as natural remedies in folk medicine has limited scientific studies to ensure its efficacy and nontoxicity. The current study reports the total phenolic content, antioxidant capacity, cytotoxicity, and acute oral toxicity of crude methanol and its fractionated extracts (hexane, ethyl acetate, and water) of G. bicolor leaves. Five human colon cancer cell lines (HT-29, HCT-15, SW480, Caco-2, and HCT 116), one human breast adenocarcinoma cell line (MCF7), and one human normal colon cell line (CCD-18Co) were used to evaluate the cytotoxicity of G. bicolor. The present findings had clearly demonstrated that ethyl acetate extract of G. bicolor with the highest total phenolic content among the extracts showed the strongest antioxidant activity (DPPH radical scavenging assay and metal chelating assay), possessed cytotoxicity, and induced apoptotic and necrotic cell death, especially towards the HCT 116 and HCT-15 colon cancer cells. The acute oral toxicity study indicated that methanol extract of G. bicolor has negligible level of toxicity when administered orally and has been regarded as safe in experimental rats. The findings of the current study clearly established the chemoprevention potential of G. bicolor and thus provide scientific validation on the therapeutic claims of G. bicolor.
    Matched MeSH terms: Acetates
  5. Fulltext Activity-Guided Isolation of Bioactive Constituents with Antinociceptive Activity from Muntingia calabura L. Leaves Using the Formalin Test
    Mohamad Yusof MI, Salleh MZ, Lay Kek T, Ahmat N, Nik Azmin NF, Zakaria ZA
    Evid Based Complement Alternat Med, 2013;2013:715074.
    PMID: 24348716 DOI: 10.1155/2013/715074
    The present study was conducted to determine the antinociceptive potential of methanol extract of Muntingia calabura L. (MEMC) and to isolate and identify the bioactive compound(s) responsible for the observed antinociceptive activity. The MEMC and its partitions (petroleum ether (PEP), ethyl acetate (EAP), and aqueous (AQP) partitions), in the dose range of 100, 500, and 1000 mg/kg, were tested using the formalin-induced nociceptive test. The PEP, which exerted the most effective activity in the respective early and late phase, was further subjected to the fractionation procedures and yielded seven fractions (labelled A to G). These fractions were tested, at the dose of 300 mg/kg, together with distilled water or 10% DMSO (negative controls); morphine and aspirin (positive controls) for potential antinociceptive activity. Of all fractions, Fraction D showed the most significant antinociceptive activity, which is considered as equieffective to morphine or aspirin in the early or late phase, respectively. Further isolation and identification processes on fraction D led to the identification of three known and one new compounds, namely, 5-hydroxy-3,7,8-trimethoxyflavone (1), 3,7-dimethoxy-5-hydroyflavone (2), 2',4'-dihydroxy-3'-methoxychalcone (3), and calaburone (4). At the dose of 50 mg/kg, compound 3 exhibited the highest percentage of antinociceptive activity in both phases of the formalin test. In conclusion, the antinociceptive activity of MEMC involved, partly, the synergistic activation of the flavonoid types of compounds.
    Matched MeSH terms: Acetates
  6. Fulltext Alternanthera sessilis Red Ethyl Acetate Fraction Exhibits Antidiabetic Potential on Obese Type 2 Diabetic Rats
    Tan KK, Kim KH
    Evid Based Complement Alternat Med, 2013;2013:845172.
    PMID: 23606892 DOI: 10.1155/2013/845172
    The antidiabetic potential of Alternanthera sessilis Red was investigated using the obese type 2 diabetic rats induced by high fat diet and streptozotocin. Three fractions (hexane, ethyl acetate, and water) were obtained from the crude ethanol extract of Alternanthera sessilis Red. Alternanthera sessilis Red ethyl acetate fraction (ASEAF) was found to possess the most potent antihyperglycemic effect through oral glucose tolerance test. The ASEAF was subsequently given to the diabetic rats for two weeks. It was found that two-week administration of ASEAF reduces the fasting blood glucose level, triglyceride level, and free fatty acid level of the rats. ASEAF-treated diabetic rats showed higher pancreatic insulin content and pancreatic total superoxide dismutase activity compared to the untreated diabetic rats. Also, the insulin sensitivity indexes suggested that ASEAF ameliorates the insulin resistant state of the diabetic rats. In conclusion, ASEAF could be developed into a potential antidiabetic agent for the management of type 2 diabetes.
    Matched MeSH terms: Acetates
  7. Quality of life assessment in patients with moderate to severe allergic rhinitis treated with montelukast and/or intranasal steroids: a randomised, double-blind, placebo-controlled study
    Goh BS, Ismail MI, Husain S
    J Laryngol Otol, 2014 Mar;128(3):242-8.
    PMID: 24618303 DOI: 10.1017/S002221511400036X
    This study investigated improvements in quality of life associated with eight weeks of montelukast and/or intranasal steroid treatment for moderate to severe allergic rhinitis.
    Matched MeSH terms: Acetates/therapeutic use*
  8. Fulltext A ten-year retrospective analysis of gastroenteropancreatic neuroendocrine tumors (GEP-NETs) in Malaysia
    Gunavathy M, Rohana AG, Norlela S, Nor Azmi K
    Med J Malaysia, 2014 Jun;69(3):133-7.
    PMID: 25326355 MyJurnal
    Gastroenteropancreatic neuroendocrine tumours (GEP- nETs) are rare neoplasms with a complex spectrum of presentation. The study cohort (n=64) included the diagnoses of carcinoid, (n=26, 41%), insulinoma, (n=25, 39%), undetermined (n=10, 16%), VIPoma, glucagonoma and multiple endocrine neoplasia (MEn-1) (n= 3). Almost half of the patients (n=31) had distant metastasis at diagnosis, the commonest being carcinoid tumours. Presenting symptoms were due to either hormonal expressions or mass effects. diagnoses in all patients were made based on positive immunohistochemical staining for chromogranin and synaptophysin. Less than half (n=30) had either serum chromogranin A, urinary 5-hydroxyindole acetic acid (5-hIAA), serum insulin or C-peptide levels performed. Commonest diagnostic imaging modalities were computed tomography (CT) scan (94%) and abdominal ultrasound (15%). Curative or palliative surgery was performed in 58 patients. Systemic therapy included long acting somatostatin analogues (n=14), chemotherapy (n=7) and interferon-α2b (n=1). nine patients died, all of who had metastatic disease at diagnosis. All patients with insulinoma (n=25) were assessed by endocrinologists whilst carcinoid tumours were mainly managed by surgeons (n=16/26). Involvements of oncologists and gastroenterologists were minimal. This study showed that patients with GEP-nETs in Malaysia commonly presented late in the disease with presence of distant metastases. Less than half had adequate hormonal and biochemical examinations performed for diagnostic as well as prognostic purposes, and only a third received systemic therapy. Lack of institutionalbased database, clinical expertise and multi-disciplinary involvement contributed to the inadequate surveillance and management of the disease.
    Matched MeSH terms: Acetates
  9. Fulltext Antihyperglycaemic and Toxicological Evaluations of Extract and Fractions of Gynura procumbens Leaves
    Algariri K, Atangwho IJ, Meng KY, Asmawi MZ, Sadikun A, Murugaiyah V
    Trop Life Sci Res, 2014 Aug;25(1):75-93.
    PMID: 25210589 MyJurnal
    The acute and sub-chronic antihyperglycaemic activity, safety margin evaluations and chemical composition of ethanol extract (EE) and fractions of Gynura procumbens (GP) were studied. Streptozotocin (STZ)-induced diabetic rats (SDRs) and the Organisation for Economic Cooperation and Development (OECD) guidelines 425 and 407 were used in the antidiabetic and toxicity studies, respectively. Biochemical and haematological data obtained from both acute and sub-chronic procedures suggest that the extract is safe at the limit test dose (2000 mg/kg); thus, the oral lethal dose (LD50) exceeds 2000 mg/kg. The acceptable daily intake (ADI) was determined to be 700 mg/kg/day. In the acute antihyperglycaemic study, the n-butanol fraction (n-BF) was found to consistently lower glucose levels the most effectively, which was also demonstrated in the 14-day study. Not only did the n-BF show the highest dose-dependent glucose-lowering action (51.2% and 62.0% at 500 mg/kg and 1000 mg/kg, respectively), its effect was the closest to that of metformin (63.6%, p<0.05). The estimated amount of flavonoids in n-BF were 62.90% and 79.68% higher than the ethyl acetate fraction (EAF) and aqueous fraction (AF), respectively (p<0.05), with a corresponding value of 61.22% and 49.33% for phenolics (p<0.05). GP leaves have a no-observed-adverse-effect-level (NOAEL) and antihyperglycaemic activity corresponding to the high content of phenols and flavonoids. Therefore, GP leaves are a promising source of new antidiabetic natural products.
    Matched MeSH terms: Acetates
  10. Fulltext Synthesis and characterization of some new 4-hydroxy-coumarin derivatives
    Al-Majedy YK, Kadhum AA, Al-Amiery AA, Mohamad AB
    Molecules, 2014 Aug 07;19(8):11791-9.
    PMID: 25105917 DOI: 10.3390/molecules190811791
    Some novel coumarins were synthesized starting from 4-hydroxycoumarin and methyl bromoacetate. The structures of the newly obtained compounds were confirmed by elemental analysis, mass, IR and NMR spectra.
    Matched MeSH terms: Acetates/chemical synthesis; Acetates/chemistry*
  11. Interactions of non-natural halogenated substrates with D-specific dehalogenase (DehD) mutants using in silico studies
    Sudi IY, Shamsir MS, Jamaluddin H, Wahab RA, Huyop F
    Biotechnology, biotechnological equipment, 2014 Sep 03;28(5):949-957.
    PMID: 26019583
    The D-2-haloacid dehalogenase of D-specific dehalogenase (DehD) from Rhizobium sp. RC1 catalyses the hydrolytic dehalogenation of D-haloalkanoic acids, inverting the substrate-product configuration and thereby forming the corresponding L-hydroxyalkanoic acids. Our investigations were focused on DehD mutants: R134A and Y135A. We examined the possible interactions between these mutants with haloalkanoic acids and characterized the key catalytic residues in the wild-type dehalogenase, to design dehalogenase enzyme(s) with improved potential for dehalogenation of a wider range of substrates. Three natural substrates of wild-type DehD, specifically, monochloroacetate, monobromoacetate and D,L-2,3-dichloropropionate, and eight other non-natural haloalkanoic acids substrates of DehD, namely, L-2-chloropropionate; L-2-bromopropionate; 2,2-dichloropropionate; dichloroacetate; dibromoacetate; trichloroacetate; tribromoacetate; and 3-chloropropionate, were docked into the active site of the DehD mutants R134A and Y135A, which produced altered catalytic functions. The mutants interacted strongly with substrates that wild-type DehD does not interact with or degrade. The interaction was particularly enhanced with 3-chloropropionate, in addition to monobromoacetate, monochloroacetate and D,L-2,3-dichloropropionate. In summary, DehD variants R134A and Y135A demonstrated increased propensity for binding haloalkanoic acid and were non-stereospecific towards halogenated substrates. The improved characteristics in these mutants suggest that their functionality could be further exploited and harnessed in bioremediations and biotechnological applications.
    Matched MeSH terms: Acetates
  12. Fulltext Characterization of a gas-purge method to access 11C-carbondioxide radioactivity in blood
    Ng, Yen, Green Mark, A.
    Jurnal Sains Nuklear Malaysia, 2014;26(2):14-16.
    MyJurnal
    Carbon-11 labeled radiotracers, such as 11C-acetate and
    11C-palmitate are widely used in positron
    emission tomography (PET) for noninvasive evaluation of myocardial metabolism under varied
    physiological conditions.These tracers are attractive probes of tissue physiology, because they are
    simply radiolabled versions of the native biochemical substrates. One of the major metabolites
    generated by these tracers upon the administration is 11CO2 produced via the citric acid cycle. In
    quantitative modeling of
    11C-acetate and
    11C-palmitate PET data, the fraction of blood
    11C
    radioactivity present as
    11CO2 needs to be measured to obtain a correct radiotracer arterial
    input function. Accordingly, the literature describes a method whereby the total blood
    11C-activity
    is counted in blood samples treated with base solution, while the fraction of
    1 1CO2 is measured
    after the blood is treated with acid followed by a 10 minutes gas-purge. However, a detailed
    description of the experimental validation of this method was not provided. The goal of this study
    was to test the reliability of a 10 minute gas purging method used to assay
    11CO2 radioactivity in
    blood
    Matched MeSH terms: Acetates
  13. Fulltext Chemical constituents of aglaia lanuginose
    Kamarulzaman, F. A., Mohamad, K., Awang, K., Lee, H. B.
    Pertanika Journal of Science & Technology, 2014;22(1):163-174.
    MyJurnal
    Our continuing research on the Aglaia genus (family Meliaceace) has led us to this first study on the chemical constituents of Aglaia lanuginose (bark). The dichloromethane extract from the bark of Aglaia lanuginose showed cytotoxicity against HL-60 leukaemia cell line (45% inhibition) at 20 µg/ml and was prioritised for further investigation. Repeated chromatography of the dichloromethane extract yielded the known dammarane triterpenes which were identified as cabralealactone (1), methyl eichlerianate (2), cabraleone (3), ocotillone (4), eichleriatone (5), eichlerianic acid (6) and shoreic acid (7) together with the known sterols, sitosterol (9) and stigmasterol (10). Another isolated compound was the aromatic 4-hydroxycinnamyl-acetate (8), which has not been reported to be present in a plant from the Meliaceae family. The structures of all the compounds were elucidated on the basis of spectroscopic methods (IR, MS and NMR). Cytotoxicity testing of 1-10 showed activity only for mixtures of (3, 4), and (5, 6).
    Matched MeSH terms: Acetates
  14. Fulltext Crystal structure of [(2R,3R,4S)-3,4-bis(acet-yloxy)-5-iodo-3,4-di-hydro-2H-pyran-2-yl]methyl acetate
    Zukerman-Schpector J, Caracelli I, Stefani HA, Shamim A, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2015 Jan 1;71(Pt 1):o53-4.
    PMID: 25705505 DOI: 10.1107/S205698901402564X
    In the title compound, C12H15IO7, the 3,4-di-hydro-2H-pyran ring is in a distorted half-boat conformation with the atom bearing the acet-yloxy group adjacent to the C atom bearing the methyl-acetate group lying 0.633 (6) Å above the plane of the remaining ring atoms (r.m.s. deviation = 0.0907 Å). In the crystal, mol-ecules are linked into a supra-molecular chain along the a axis through two C-H⋯O inter-actions to the same acceptor carbonyl O atom; these chains pack with no specific inter-molecular inter-actions between them.
    Matched MeSH terms: Acetates
  15. Fulltext Crystal structure of 1-benzyl-2-hy-droxy-5-oxopyrrolidin-3-yl acetate
    Caracelli I, Zukerman-Schpector J, Stefani HA, Ali B, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2015 Aug 1;71(Pt 8):o582-3.
    PMID: 26396808 DOI: 10.1107/S2056989015013353
    In the title compound, C13H15NO4, the oxopyrrolidin-3-yl ring has an envelope conformation, with the C atom bearing the acetate group being the flap. The acetate and phenyl groups are inclined with respect to the central ring, forming dihedral angles of 50.20 (12) and 87.40 (9)°, respectively, with the least-squares plane through the ring. The dihedral angle between the acetate group and the phenyl ring is 63.22 (8)°, indicating a twisted conformation in the mol-ecule. In the crystal, supra-molecular chains along the b axis are formed by (hy-droxy)O-H⋯O(ring carbon-yl) hydrogen bonds. The chains are consolidated into the three-dimensional architecture by C-H⋯O inter-actions.
    Matched MeSH terms: Acetates
  16. Fulltext Montelukast sodium-induced hypomania
    Zainal, N.Z., Tan, T.Y
    Malaysian Journal of Psychiatry, 2015;24(1):96-98.
    MyJurnal
    Objective: A rare case of induced hypomania was reported. Method: Patient was a 78-year-old Indian female with squamous cell carcinoma of the nasal septum, childhood bronchial asthma and underlying bipolar disorder. Her bipolar disorder is currently in remission. She developed hypomanic symptoms after one week of initiation of montelukast sodium for treatment of acute exacerbation of bronchial asthma. Result: Her hypomanic symptoms improved after stopping usage of montelukast sodium. Conclusion: Montelukast sodium likely had induced hypomania in this patient.
    Matched MeSH terms: Acetates
  17. Isolation and fractionation of cellulose nanocrystals from kenaf core
    Hanisah Syed Sulaiman, Chin HC, Chan CH, Sarani Zakaria, Sharifah Nabihah Syed Jaafar
    Sains Malaysiana, 2015;44:1635-1642.
    In this study, cellulose nanocrystals (CNC) were produced using acid hydrolysis method. Kenaf core was pretreated with 4
    wt. % sodium hydroxide (NaOH), followed by bleaching using 1.7 wt. % sodium chlorite (NaClO2
    ) in acetate buffer. The
    bleached fiber was acid hydrolyzed for 45 and 55 min using 64 wt. % sulfuric acid (H2
    SO4
    ). The size distribution of the
    CNC segregated via differential centrifugation with different speed was also investigated. The CNC suspension obtained
    was centrifuged at 3000, 6000, 9000 and 12000 rpm. The resultant CNC suspension collected was characterized using
    Fourier transform infrared (FTIR) analysis, X-ray diffraction (XRD) and transmission electron microscopy (TEM). FTIR
    results showed the progressive removal of non-cellulosic constituents for each subsequent treatment. It also showed that
    the CNC produced after hydrolysing for 55 min has the highest degree of crystallinity (81.15%). CNC produced from acid
    hydrolysis process of 45 min have lengths between 50 and 270 nm while CNC produced from acid hydrolysis process of
    55 min have length around 40 to 370 nm.
    Matched MeSH terms: Acetates
  18. Mechanical and antibacterial properties of paper coated with chitosan
    Sarani Zakaria, Chin HC, Wan Haslinda Wan Ahmad, Hatika Kaco, Soon Wei Chook, Chi HC
    Sains Malaysiana, 2015;44:905-911.
    Recent developments have found the viability of chitosan as a new alternative additive in the pulp and paper technology.
    This study was carried out to investigate the effect of chitosan as a paper coating which were prepared by dissolution in
    acetic acid solution. The mechanical properties of coated paper were improved significantly compared with non-coated
    paper. The FT-IR spectra showed peak evolution at 1558 cm-1 for coated paper due to the existence of amine group. Since
    FT-IR spectra for the coated paper was almost identical to the chitosan spectrum, it is assumed that there is an obvious
    physical interaction rather than the chemical interaction. The SEM micrographs showed that some of the chitosan has
    occupied the pores and some of them adhered only on the surface. This may be due to the chemical similarities between
    cellulose and chitosan which enhanced the strength of fiber matrixes via hydrogen bonding. The antibacterial property
    of coated paper showed that chitosan in dried form has no significant effect but effective when applied as wet solution.
    Matched MeSH terms: Acetates
  19. Fulltext Induction of Apoptosis in MCF-7 Cells via Oxidative Stress Generation, Mitochondria-Dependent and Caspase-Independent Pathway by Ethyl Acetate Extract of Dillenia suffruticosa and Its Chemical Profile
    Tor YS, Yazan LS, Foo JB, Wibowo A, Ismail N, Cheah YK, et al.
    PLoS One, 2015;10(6):e0127441.
    PMID: 26047480 DOI: 10.1371/journal.pone.0127441
    Dillenia suffruticosa, which is locally known as Simpoh air, has been traditionally used to treat cancerous growth. The ethyl acetate extract of D. suffruticosa (EADs) has been shown to induce apoptosis in MCF-7 breast cancer cells in our previous study. The present study aimed to elucidate the molecular mechanisms involved in EADs-induced apoptosis and to identify the major compounds in the extract. EADs was found to promote oxidative stress in MCF-7 cells that led to cell death because the pre-treatment with antioxidants α-tocopherol and ascorbic acid significantly reduced the cytotoxicity of the extract (P<0.05). DCFH-DA assay revealed that treatment with EADs attenuated the generation of intracellular ROS. Apoptosis induced by EADs was not inhibited by the use of caspase-inhibitor Z-VAD-FMK, suggesting that the cell death is caspase-independent. The use of JC-1 dye reflected that EADs caused disruption in the mitochondrial membrane potential. The related molecular pathways involved in EADs-induced apoptosis were determined by GeXP multiplex system and Western blot analysis. EADs is postulated to induce cell cycle arrest that is p53- and p21-dependent based on the upregulated expression of p53 and p21 (P<0.05). The expression of Bax was upregulated with downregulation of Bcl-2 following treatment with EADs. The elevated Bax/Bcl-2 ratio and the depolarization of mitochondrial membrane potential suggest that EADs-induced apoptosis is mitochondria-dependent. The expression of oxidative stress-related AKT, p-AKT, ERK, and p-ERK was downregulated with upregulation of JNK and p-JNK. The data indicate that induction of oxidative-stress related apoptosis by EADs was mediated by inhibition of AKT and ERK, and activation of JNK. The isolation of compounds in EADs was carried out using column chromatography and elucidated using the nuclear resonance magnetic analysis producing a total of six compounds including 3-epimaslinic acid, kaempferol, kaempferide, protocatechuic acid, gallic acid and β-sitosterol-3-O-β-D-glucopyranoside. The cytotoxicity of the isolated compounds was determined using MTT assay. Gallic acid was found to be most cytotoxic against MCF-7 cell line compared to others, with IC50 of 36 ± 1.7 μg/mL (P<0.05). In summary, EADs generated oxidative stress, induced cell cycle arrest and apoptosis in MCF-7 cells by regulating numerous genes and proteins that are involved in the apoptotic signal transduction pathway. Therefore, EADs has the potential to be developed as an anti-cancer agent against breast cancer.
    Matched MeSH terms: Acetates/chemistry
  20. Mobility Studies of (14)C-Chlorpyrifos in Malaysian Oil Palm Soils
    Halimah M, Ismail BS, Nashriyah M, Maznah Z
    Bull Environ Contam Toxicol, 2016 Jan;96(1):120-4.
    PMID: 26546229 DOI: 10.1007/s00128-015-1685-3
    The mobility of (14)C-chlorpyrifos using soil TLC was investigated in this study. It was found that chlorpyrifos was not mobile in clay, clay loam and peat soil. The mobility of (14)C-chlorpyrifos and non-labelled chlorpyrifos was also tested with silica gel TLC using three types of developing solvent hexane (100%), hexane:ethyl acetate (95:5, v/v); and hexane:ethyl acetate (98:2, v/v). The study showed that both the (14)C-labelled and non-labelled chlorpyrifos have the same Retardation Factor (Rf) for different developing solvent systems. From the soil column study on mobility of chlorpyrifos, it was observed that no chlorpyrifos residue was found below 5 cm depth in three types of soil at simulation rainfall of 20, 50 and 100 mm. Therefore, the soil column and TLC studies have shown similar findings in the mobility of chlorpyrifos.
    Matched MeSH terms: Acetates
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