Displaying publications 21 - 34 of 34 in total

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  1. Seet WT, Mat Afandi MA, Ishak MF, Hassan MNF, Ahmat N, Ng MH, et al.
    Stem Cell Res Ther, 2023 Oct 20;14(1):298.
    PMID: 37858277 DOI: 10.1186/s13287-023-03536-9
    Treatments for skin injuries have recently advanced tremendously. Such treatments include allogeneic and xenogeneic transplants and skin substitutes such as tissue-engineered skin, cultured cells, and stem cells. The aim of this paper is to discuss the general overview of the quality assurance and quality control implemented in the manufacturing of cell and tissue product, with emphasis on our experience in the manufacturing of MyDerm®, an autologous bilayered human skin substitute. Manufacturing MyDerm® requires multiple high-risk open manipulation steps, such as tissue processing, cell culture expansion, and skin construct formation. To ensure the safety and efficacy of this product, the good manufacturing practice (GMP) facility should establish a well-designed quality assurance and quality control (QA/QC) programme. Standard operating procedures (SOP) should be implemented to ensure that the manufacturing process is consistent and performed in a controlled manner. All starting materials, including tissue samples, culture media, reagents, and consumables must be verified and tested to confirm their safety, potency, and sterility. The final products should also undergo a QC testing series to guarantee product safety, efficacy, and overall quality. The aseptic techniques of cleanroom operators and the environmental conditions of the facility are also important, as they directly influence the manufacturing of good-quality products. Hence, personnel training and environmental monitoring are necessary to maintain GMP compliance. Furthermore, risk management implementation is another important aspect of QA/QC, as it is used to identify and determine the risk level and to perform risk assessments when necessary. Moreover, procedures for non-conformance reporting should be established to identify, investigate, and correct deviations that occur during manufacturing. This paper provides insight and an overview of the QA/QC aspect during MyDerm® manufacturing in a GMP-compliant facility in the Centre for Tissue Engineering and Regenerative Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia.
  2. Mohamad Yusof MI, Salleh MZ, Lay Kek T, Ahmat N, Nik Azmin NF, Zakaria ZA
    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.
  3. Zawawi NK, Taha M, Ahmat N, Wadood A, Ismail NH, Rahim F, et al.
    Bioorg Chem, 2016 Feb;64:29-36.
    PMID: 26637946 DOI: 10.1016/j.bioorg.2015.11.006
    Newly synthesized benzimidazole hydrazone derivatives 1-26 were evaluated for their α-glucosidase inhibitory activity. Compounds 1-26 exhibited varying degrees of yeast α-glucosidase inhibitory activity with IC50 values between 8.40 ± 0.76 and 179.71 ± 1.11 μM when compared with standard acarbose. In this assay, seven compounds that showed highest inhibitory effects than the rest of benzimidazole series were identified. All the synthesized compounds were characterized by different spectroscopic methods adequately. We further evaluated the interaction of the active compounds with enzyme with the help of docking studies.
  4. Jalil J, Sabandar CW, Ahmat N, Jamal JA, Jantan I, Aladdin NA, et al.
    Molecules, 2015 Feb 16;20(2):3206-20.
    PMID: 25690285 DOI: 10.3390/molecules20023206
    The crude methanol extracts and fractions of the root and stem barks of Dillenia serrata Thunb. showed 64% to 73% inhibition on the production of prostaglandin E2 (PGE2) in lipopolysaccharide-induced human whole blood using a radioimmunoassay technique. Three triterpenoids isolated from the root bark of the plant, koetjapic (1), 3-oxoolean-12-en-30-oic (2), and betulinic (3) acids, exhibited significant concentration-dependent inhibitory effects on PGE2 production with IC50 values of 1.05, 1.54, and 2.59 μM, respectively, as compared with the positive control, indomethacin (IC50 = 0.45 μM). Quantification of compounds 1 and 3 in the methanol extracts and fractions were carried out by using a validated reversed-phase high performance liquid chromatography (RP-HPLC) method. The ethyl acetate fraction of the stem bark showed the highest content of both compound 1 (15.1%) and compound 3 (52.8%). The strong inhibition of the extracts and fractions on cyclooxygenase-2 (COX-2) enzymatic activity was due to the presence of their major constituents, especially koetjapic and betulinic acids.
  5. Al Muqarrabun LM, Ahmat N, Aris SR, Norizan N, Shamsulrijal N, Yusof FZ, et al.
    Nat Prod Res, 2014;28(13):1003-9.
    PMID: 24697194 DOI: 10.1080/14786419.2014.903396
    A new triterpene, malaytaraxerate (1), and four known compounds, taraxerol (2), taraxerone (3), docosyl isoferulate (4) and docosanoic acid 2',3'-dihydroxypropyl ester (5), were isolated from the acetone extract of Sapium baccatum stem bark. The structures of the isolated compounds were determined using several spectroscopic methods, including UV-Vis, FT-IR, 1D and 2D NMR, and mass spectrometry. Major isolated compounds were assayed for cytotoxicity. The chemotaxonomic significance of this plant was also studied.
  6. Al Muqarrabun LM, Ahmat N, Aris SR, Shamsulrijal N, Baharum SN, Ahmad R, et al.
    Nat Prod Res, 2014;28(9):597-605.
    PMID: 24568340 DOI: 10.1080/14786419.2014.886211
    A new sesquiterpenoid, malayscaphiol (1), and three known compounds, lupeol (2), lupenone (3) and stigmasterol (4), were isolated from the methanolic extract of the stem bark of Scaphium macropodum. The structures of the isolated compounds were determined using several spectroscopic methods, including UV-vis, FT-IR, 1D and 2D NMR, and mass spectrometer. Major isolated compounds were assayed for cytotoxicity and anti-acetylcholinesterase activities. The chemotaxonomy significance of this plant was also discussed.
  7. Koh KC, Lau KM, Yusof SA, Mohamad AI, Shahabuddin FS, Ahmat NH, et al.
    Med J Malaysia, 2015 Dec;70(6):334-40.
    PMID: 26988205 MyJurnal
    INTRODUCTION: Misinterpretation of abbreviations by healthcare professionals has been reported to compromise patient safety. This study was done to determine the prevalence of abbreviations usage among medical doctors and nurses and their ability to interpret commonly used abbreviations in medical practice.

    METHODS: Seventy-seven medical doctors and eighty nurses answered a self-administered questionnaire designed to capture demographic data and information regarding abbreviation use in medical practice. Comparisons were made between doctors and nurses with regards to frequency and reasons for using abbreviations; from where abbreviations were learned; frequency of encountering abbreviations in medical practice; prevalence of medical errors due to misinterpretation of abbreviations; and their ability to correctly interpret commonly used abbreviations.

    RESULTS: The use of abbreviations was highly prevalent among doctors and nurses. Time saving, avoidance of writing sentences in full and convenience, were the main reasons for using abbreviations. Doctors learned abbreviations from fellow doctors while nurses learned from fellow nurses and doctors. More doctors than nurses reported encountering abbreviations. Both groups reported no difficulties in interpreting abbreviations although nurses reported often resorting to guesswork. Both groups felt abbreviations were necessary and an acceptable part of work. Doctors outperformed nurses in correctly interpreting commonly used standard and non-standard abbreviations.

    CONCLUSION: The use of standard and non-standard abbreviation in clinical practice by doctors and nurses was highly prevalent. Significant variability in interpretation of abbreviations exists between doctors and nurses.

  8. Zawawi NK, Taha M, Ahmat N, Wadood A, Ismail NH, Rahim F, et al.
    Bioorg Med Chem, 2015 Jul 1;23(13):3119-25.
    PMID: 26001340 DOI: 10.1016/j.bmc.2015.04.081
    A library of novel 2,5-disubtituted-1,3,4-oxadiazoles with benzimidazole backbone (3a-3r) was synthesized and evaluated for their potential as β-glucuronidase inhibitors. Several compounds such as 3a-3d, 3e-3j, 3l-3o, 3q and 3r showed excellent inhibitory potentials much better than the standard (IC50=48.4±1.25μM: d-saccharic acid 1,4-lactone). All the synthesized compounds were characterized satisfactorily by using different spectroscopic methods. We further evaluated the interaction of the active compounds and the enzyme active site with the help of docking studies.
  9. Zawawi NK, Rajput SA, Taha M, Ahmat N, Ismail NH, Abdullah N, et al.
    Bioorg Med Chem Lett, 2015 Oct 15;25(20):4672-6.
    PMID: 26330080 DOI: 10.1016/j.bmcl.2015.08.022
    Apoptotic cell death is the cause of the loss of insulin-producing β-cells in all forms of diabetes mellitus. The identification of small molecules capable of protecting cytokine-induced apoptosis could form the basis of useful therapeutic interventions. Here in, we present the discovery and synthesis of new benzimidazole derivatives, capable of rescuing pancreatic β-cells from cytokine-induced apoptosis. Three hydrazone derivatives of benzimidazole significantly increased the cellular ATP levels, reduced caspase-3 activity, reduced nitrite production and increased glucose-stimulated insulin secretion in the presence of proinflammatory cytokines. These findings suggest that these compounds may protect β-cells from the harmful effects of cytokines and may serve as candidates for therapeutic intervention for diabetes.
  10. Taha M, Ismail NH, Imran S, Wadood A, Rahim F, Al Muqarrabin LM, et al.
    Bioorg Chem, 2016 10;68:15-22.
    PMID: 27414468 DOI: 10.1016/j.bioorg.2016.07.002
    Novel series of disulfide and sulfone hybrid analogs (1-20) were synthesized and characterized through EI-MS and (1)H NMR and evaluated for β-glucuronidase inhibitory potential. All synthesized analogs except 13 and 15 showed excellent β-glucuronidase inhibitory potential with IC50 value ranging in between 2.20-88.16μM as compared to standard d-saccharic acid 1,4 lactone (48.4±1.25μM). Analogs 19, 16, 4, 1, 17, 6, 10, 3, 18, 2, 11, 14 and 5 showed many fold potent activity against β-glucuronidase inhibitor. Structure activity relationship showed that substitution of electron withdrawing groups at ortho as well as para position on phenyl ring increase potency. Electron withdrawing groups at meta position on phenyl ring showed slightly low potency as compared to ortho and para position. The binding interactions were confirmed through molecular docking studies.
  11. Gollapalli M, Taha M, Ullah H, Nawaz M, AlMuqarrabun LMR, Rahim F, et al.
    Bioorg Chem, 2018 10;80:112-120.
    PMID: 29894890 DOI: 10.1016/j.bioorg.2018.06.001
    In search of better α-glucosidase inhibitors, a series of bis-indolylmethane sulfonohydrazides derivatives (1-14) were synthesized and evaluated for their α-glucosidase inhibitory potential. All derivatives exhibited outstanding α-glucosidase inhibition with IC50 values ranging between 0.10 ± 0.05 to 5.1 ± 0.05 μM when compared with standard drug acarbose having IC50 value 856.28 ± 3.15 μM. Among the series, analog 7 (0.10 ± 0.05 μM) with tri-chloro substitution on phenyl ring was identified as the most potent inhibitor of α-glucosidase (∼ 8500 times). The structure activity relationship has been also established. Molecular docking studies were also performed to help understand the binding interaction of the most active analogs with receptors. From the docking studies, it was observed that all the active bis-indolylmethane sulfonohydrazides derivatives showed considerable binding interactions within the active site (acarbose inhibition site) of α-glucosidase. We also evaluated toxicity of all derivatives and found none of them are toxic.
  12. Rahman NA, Yazan LS, Wibowo A, Ahmat N, Foo JB, Tor YS, et al.
    PMID: 27609190 DOI: 10.1186/s12906-016-1328-1
    Several compounds isolated from Dryobalanops have been reported to exhibit cytotoxic effects to several cancer cell lines. This study investigated the cytotoxic effects, cell cycle arrest and mode of cell death in ampelopsin E-treated triple negative cells, MDA-MB-231.
  13. Taha M, Ullah H, Al Muqarrabun LMR, Khan MN, Rahim F, Ahmat N, et al.
    Bioorg Med Chem, 2018 01 01;26(1):152-160.
    PMID: 29183662 DOI: 10.1016/j.bmc.2017.11.028
    Bisindolylmethane thiosemicarbazides 1-18 were synthesized, characterized by 1H NMR and ESI MS and evaluated for urease inhibitory potential. All analogs showed outstanding urease inhibitory potentials with IC50 values ranging between 0.14 ± 0.01 to 18.50 ± 0.90 μM when compared with the standard inhibitor thiourea having IC50 value 21.25 ± 0.90 μM. Among the series, analog 9 (0.14 ± 0.01 μM) with di-chloro substitution on phenyl ring was identified as the most potent inhibitor of urease. The structure activity relationship has been also established on the basis of binding interactions of the active analogs. These binding interactions were identified by molecular docking studies.
  14. Aziz AN, Taha M, Ismail NH, Anouar el H, Yousuf S, Jamil W, et al.
    Molecules, 2014 Jun 19;19(6):8414-33.
    PMID: 24950444 DOI: 10.3390/molecules19068414
    Schiff bases of 3,4-dimethoxybenzenamine 1-25 were synthesized and evaluated for their antioxidant activity. All the synthesized compounds were characterized by various spectroscopic techniques. In addition, the characterizations of compounds 13, 15 and 16 were supported by crystal X-ray determinations and their geometrical parameters were compared with theoretical DFT calculations at the B3LYP level of theory. Furthermore, the X-ray crystal data of two non-crystalline compounds 8 and 18 were theoretically calculated and compared with the practical values of compounds 13, 15, 16 and found a good agreement. The compounds showed good DPPH scavenging activity ranging from 10.12 to 84.34 μM where compounds 1-4 and 6 showed stronger activity than the standard n-propyl gallate. For the superoxide anion radical assay, compounds 1-3 showed better activity than the standard.
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