Displaying publications 1241 - 1260 of 6934 in total

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  1. Anti-nociceptive mechanisms of flavonoids-rich methanolic extract from Terminalia coriacea (Roxb.) Wight & Arn. leaves
    Ali Khan MS, Ahmed N, Misbah, Arifuddin M, Zakaria ZA, Al-Sanea MM, et al.
    Food Chem Toxicol, 2018 May;115:523-531.
    PMID: 29555329 DOI: 10.1016/j.fct.2018.03.021
    In view of the report on anti-nociceptive activity of Leathery Murdah, Terminalia coriacea {Roxb.} Wight & Arn. (Combretaceae) leaves, the present study was conducted to isolate the active constituents and identify the underlying mechanisms. The methanolic extract of T. coriacea leaves (TCLME) at doses 125, 250 and 500 mg/kg orally, was subjected to various in-vivo assays in acetic acid induced writhing and formalin induced paw-licking tests with aspirin (100 mg/kg) and morphine (5 mg/kg) as reference drugs. Three flavonoids, rutin, robinin and gossypetin 3-glucuronide 8-glucoside were isolated and characterized from TCLME for the first time. The extract showed significant (p 
    Matched MeSH terms: Analgesics/pharmacology*; Flavonoids/pharmacology*; Glyburide/pharmacology; Plant Extracts/pharmacology*
  2. Fulltext Combining In Silico and In Vitro Studies to Evaluate the Acetylcholinesterase Inhibitory Profile of Different Accessions and the Biomarker Triterpenes of Centella asiatica
    Jusril NA, Muhamad Juhari ANN, Abu Bakar SI, Md Saad WM, Adenan MI
    Molecules, 2020 Jul 24;25(15).
    PMID: 32721993 DOI: 10.3390/molecules25153353
    Alzheimer's disease (AD) is a neurodegenerative disease and the most cause of dementia in elderly adults. Acetylcholinesterase (AChE) is an important beneficial target for AD to control cholinergic signaling deficit. Centella asiatica (CA) has proven to be rich with active ingredients for memory enhancement. In the present study, the chemical profiling of three accession extracts of CA namely SECA-K017, SECA-K018, and, SECA-K019 were performed using high-performance liquid chromatography (HPLC). Four biomarker triterpene compounds were detected in all CA accessions. Quantitative analysis reveals that madecassoside was the highest triterpene in all the CA accessions. The biomarker compounds and the ethanolic extracts of three accessions were investigated for their acetylcholinesterase (AChE) inhibitory activity using Ellman's spectrophotometer method. The inhibitory activity of the triterpenes and accession extracts was compared with the standard AChE inhibitor eserine. The results from the in vitro study showed that the triterpene compounds exhibited an AChE inhibitory activity with the half-maximal inhibitory concentration (IC50) values between 15.05 ± 0.05 and 59.13 ± 0.18 µg/mL. Asiatic acid was found to possess strong AChE inhibitory activity followed by madecassic acid. Among the CA accession extracts, SECA-K017 and SECA-K018 demonstrated a moderate AChE inhibitory activity with an IC50 value of 481.5 ± 0.13 and 763.5 ± 0.16 µg/mL, respectively from the in silico docking studies, it is observed that asiatic acid and madecassic acid showed very good interactions with the active sites and fulfilled docking parameters against AChE. The present study suggested that asiatic acid and madecassic acid in the CA accessions could be responsible for the AChE inhibitory action and could be used as markers to guide further studies on CA as potential natural products for the treatment of AD.
    Matched MeSH terms: Cholinesterase Inhibitors/pharmacology*; Physostigmine/pharmacology; Triterpenes/pharmacology; Pentacyclic Triterpenes/pharmacology*
  3. Antifungal garcinia acid esters from the fruits of Garcinia atroviridis
    Mackeen MM, Ali AM, Lajis NH, Kawazu K, Kikuzaki H, Nakatani N
    Z Naturforsch C J Biosci, 2002 6 18;57(3-4):291-5.
    PMID: 12064729
    Two new garcinia acid derivatives, 2-(butoxycarbonylmethyl)-3-butoxycarbonyl-2-hydroxy-3-propanolide and 1',1"-dibutyl methyl hydroxycitrate, were isolated from the fruits of Garcinia atroviridis guided by TLC bioautography against the fungus Cladosporium herbarum. The structures of these compounds were established by spectral analysis. The former compound represents a unique beta-lactone structure and the latter compound is most likely an artefact of garcinia acid (= hydroxycitric acid). Both compounds showed selective antifungal activity comparable to that of cycloheximide (MID: 0.5 microg/spot) only against C herbarum at the MIDs of 0.4 and 0.8 microg/spot but were inactive against bacteria (Bacillus subtilis, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli), other fungi (Alternaria sp., Fusarium moniliforme and Aspergillus ochraceous) including the yeast Candida albicans.
    Matched MeSH terms: Antifungal Agents/pharmacology; Citrates/pharmacology; Cycloheximide/pharmacology; Lactones/pharmacology
  4. Fluoxetine potentiates chloroquine and mefloquine effect on multidrug-resistant Plasmodium falciparum in vitro
    Khairul MF, Min TH, Low JH, Nasriyyah CH, A'shikin AN, Norazmi MN, et al.
    Jpn J Infect Dis, 2006 Oct;59(5):329-31.
    PMID: 17060702
    Fluoxetine (FLX), a P-glycoprotein inhibitor with antimalarial activity, is promising candidate for reversing chloroquine/mefloquine (CQ/MQ) resistance. The Dd2 strain of CQ- and MQ-resistant Plasmodium falciparum was synchronized and assayed with various concentrations of CQ/MQ individually and in combination with FLX or verapamil (VPL). Our results indicated the 50% inhibitory concentration values of CQ and MQ were greatly lowered when FLX was used simultaneously. Isobolograms indicated that CQ-FLX combinations are more synergistic (mean fractional inhibitory concentration [FIC] index 0.55) than MQ-FLX (mean FIC index 0.64), and their synergistic effect was better than or at par with CQ-VPL (mean FIC index 0.88) and MQ-VPL (mean FIC index 0.60) combinations. We conclude that the FLX potentiates the CQ and MQ response on multidrug-resistant P. falciparum at clinically achievable concentrations.
    Matched MeSH terms: Antimalarials/pharmacology*; Chloroquine/pharmacology*; Fluoxetine/pharmacology*; Mefloquine/pharmacology*
  5. Sulforaphane is superior to glucoraphanin in modulating carcinogen-metabolising enzymes in Hep G2 cells
    Abdull Razis AF, Noor NM
    Asian Pac J Cancer Prev, 2013;14(7):4235-8.
    PMID: 23991982
    Glucoraphanin is the main glucosinolate found in broccoli and other cruciferous vegetables (Brassicaceae). The objective of the study was to evaluate whether glucoraphanin and its breakdown product sulforaphane, are potent modulators of various phase I and phase II enzymes involved in carcinogen-metabolising enzyme systems in vitro. The glucosinolate glucoraphanin was isolated from cruciferous vegetables and exposed to human hepatoma cell line HepG2 at various concentrations (0-25 μM) for 24 hours. Glucoraphanin at higher concentration (25 μM) decreased dealkylation of methoxyresorufin, a marker for cytochrome P4501 activity; supplementation of the incubation medium with myrosinase (0.018 U), the enzyme that converts glucosinolate to its corresponding isothiocyanate, showed minimal induction in this enzyme activity at concentration 10 μM. Quinone reductase and glutathione S-transferase activities were unaffected by this glucosinolate; however, supplementation of the incubation medium with myrosinase elevated quinone reductase activity. It may be inferred that the breakdown product of glucoraphanin, in this case sulforaphane, is superior than its precursor in modulating carcinogen- metabolising enzyme systems in vitro and this is likely to impact on the chemopreventive activity linked to cruciferous vegetable consumption.
    Matched MeSH terms: Glucosinolates/pharmacology*; Imidoesters/pharmacology*; Anticarcinogenic Agents/pharmacology; Isothiocyanates/pharmacology*
  6. Gamma-tocotrienol acts as a BH3 mimetic to induce apoptosis in neuroblastoma SH-SY5Y cells
    Tan JK, Then SM, Mazlan M, Raja Abdul Rahman RN, Jamal R, Wan Ngah WZ
    J Nutr Biochem, 2016 May;31:28-37.
    PMID: 27133421 DOI: 10.1016/j.jnutbio.2015.12.019
    Bcl-2 family proteins are crucial regulators of apoptosis. Both pro- and antiapoptotic members exist, and overexpression of the latter facilitates evasion of apoptosis in many cancer types. Bcl-2 homology domain 3 (BH3) mimetics are small molecule inhibitors of antiapoptotic Bcl-2 family members, and these inhibitors are promising anticancer agents. In this study, we report that gamma-tocotrienol (γT3), an isomer of vitamin E, can inhibit Bcl-2 to induce apoptosis. We demonstrate that γT3 induces cell death in human neuroblastoma SH-SY5Y cells by depolarising the mitochondrial membrane potential, enabling release of cytochrome c to the cytosol and increasing the activities of caspases-9 and -3. Treatment of cells with inhibitors of Bax or caspase-9 attenuated the cell death induced by γT3. Simulated docking analysis suggested that γT3 binds at the hydrophobic groove of Bcl-2, while a binding assay showed that γT3 competed with a fluorescent probe to bind at the hydrophobic groove. Our data suggest that γT3 mimics the action of BH3-only protein by binding to the hydrophobic groove of Bcl-2 and inducing apoptosis via the intrinsic pathway in a Bax- and caspase-9-dependent manner.
    Matched MeSH terms: Chromans/pharmacology*; Peptide Fragments/pharmacology*; Proto-Oncogene Proteins/pharmacology*; Vitamin E/pharmacology
  7. Monoamine oxidase inhibitory naphthoquinone and/or naphthalene dimers from Lemuni Hitam (Diospyros sp.), a Malaysian herbal medicine
    Okuyama E, Homma M, Satoh Y, Fujimoto H, Ishibashi M, Yamazaki M, et al.
    Chem Pharm Bull (Tokyo), 1999 Oct;47(10):1473-6.
    PMID: 10553643
    From the extract of a Malaysian herbal medicine, Lemuni Hitam (Diospyros sp.), which exhibited monoamine oxidase (MAO) inhibition, three new naphthoquinone and/or naphthalene dimers (lemuninols A-C, 1-3) were isolated together with 4,6-dihydroxy-5-methoxy-2-methyl-naphthalene (8) and six known monomers (4-7, 9 and 10). The structures were determined by spectroscopic methods including 2D-NMR techniques. Among them, lemuninol A showed 45% inhibition of MAO (mouse liver) at 5.0 x 10(-6) g/ml, and lemuninols B and C and a naphthoquinone (9) indicated weak activity. Some related quinones were also tested for their MAO inhibitory activities.
    Matched MeSH terms: Monoamine Oxidase Inhibitors/pharmacology; Naphthalenes/pharmacology; Naphthoquinones/pharmacology; Plant Extracts/pharmacology*
  8. Fulltext Effect of Hybrid mono/bimetallic Nanocomposites for an enhancement of Catalytic and Antimicrobial Activities
    Sivaranjan K, Padmaraj O, Santhanalakshmi J, Sathuvan M, Sathiyaseelan A, Sagadevan S
    Sci Rep, 2020 02 13;10(1):2586.
    PMID: 32054936 DOI: 10.1038/s41598-020-59491-5
    Exploring the new catalytic systems for the reduction of organic and inorganic pollutants from an indispensable process in chemical, petrochemical, pharmaceutical and food industries, etc. Hence, in the present work, authors motivated to synthesize bare reduced graphene oxide (rGO), polyaniline (PANI), three different ratios of rGO-PANI(80:20,50:50, 10:90) composites and rGO-PANI(80:20,50:50, 10:90) supported mono (Pd) & bimetallic [Pd: Au(1:1,1:2, 2:1)] nanocomposite by a facile chemical reduction method. Also, it investigated their catalytic performances for the reduction of organic/inorganic pollutants and antimicrobial activities. All the freshly prepared bare rGO, PANI, three different ratios of rGO-PANI(80:20, 50:50,10:90) composites and rGO-PANI(80:20, 50:50,10:90)/Pd & Pd: Au(1:1, 1:2,2:1) nanocomposite hybrid catalysts were characterized using UV-Vis, FT-IR, SEM, FE-SEM, EDAX, HR-TEM, XRD, XPS and Raman spectroscopy analysis. Among them, an optimized best composition of rGO-PANI(80:20)/Pd: Au(1:1) bimetallic nanocomposite hybrid catalyst exhibits better catalytic reduction and antimicrobial activities than other composites, as a result of strong electrostatic interactions between rGO, PANI and bimetal (Pd: Au) NPs through a synergistic effect. Hence, an optimized rGO-PANI(80:20)/Pd:Au(1:1) bimetallic nanocomposite catalyst would be considered as a suitable catalyst for the reduction of different nitroarenes, organic dyes, heavy metal ions and also significantly inhibit the growth of S. aureus, S. Typhi as well as Candida albicans and Candida kruesi in wastewater.
    Matched MeSH terms: Aniline Compounds/pharmacology; Gold/pharmacology; Graphite/pharmacology; Palladium/pharmacology
  9. Fulltext Optimization of Protective Agents for The Freeze-Drying of Paenibacillus polymyxa Kp10 as a Potential Biofungicide
    Nasran HS, Mohd Yusof H, Halim M, Abdul Rahman N
    Molecules, 2020 Jun 04;25(11).
    PMID: 32512825 DOI: 10.3390/molecules25112618
    Anthracnose is a fungal disease causing major losses in crop production. Chemical fungicides widely used in crop plantations to combat fungal infections can be a threat to the environment and humans in the long term. Recently, biofungicides have gained much interest as an alternative to chemical fungicides due to their environmentally friendly nature. Biofungicide products in powder form can be formulated using the freeze-drying technique to provide convenient storage. Protective agent formulation is needed in maintaining the optimal viable cells of biofungicide products. In this study, 8.10 log colony-forming unit (CFU)/mL was the highest cell viability of Paenibacillus polymyxa Kp10 at 22 h during incubation. The effects of several selected protective agents on the viability of P. polymyxa Kp10 after freeze-drying were studied. Response surface methodology (RSM) was used for optimizing formulation for the protective agents. The combination of lactose (10% w/v), skim milk (20% w/v), and sucrose (27.5% w/v) was found to be suitable for preserving P. polymyxa Kp10 during freeze-drying. Further, P. polymyxa Kp10 demonstrated the ability to inhibit fungal pathogens, Colletotrichum truncatum and C. gloeosporioides, at 60.18% and 66.52% of inhibition of radial growth, respectively.
    Matched MeSH terms: Antifungal Agents/pharmacology*; Cryoprotective Agents/pharmacology*; Lactose/pharmacology; Sucrose/pharmacology
  10. Multitargeted therapy of cancer by tocotrienols
    Nesaretnam K
    Cancer Lett, 2008 Oct 8;269(2):388-95.
    PMID: 18504069 DOI: 10.1016/j.canlet.2008.03.063
    Natural compounds with possible health benefits have become attractive targets for research in areas pertaining to human health. For both prevention and therapy of various human ailments, such compounds are preferred over synthetic ones due to their lesser toxicity. They are also easily absorbed and processed by our body. Vitamins are prominent among natural or endogenous compounds that are considered to be beneficial. The vitamin E group of compounds is among the better known of the vitamins due to their suggested health benefits including antioxidant and related protective properties. Among these, tocotrienols have gained prominence in recent years due to their potential applications and better protective effects in certain systems. These tocotrienols are vitamin E derivatives that are analogs of the more established forms of vitamin E namely tocopherols. In addition to their potent antioxidant activity, tocotrienols have other important functions, especially in maintaining a healthy cardiovascular system and a possible role in protection against cancer and other ailments.
    Matched MeSH terms: Antineoplastic Agents/pharmacology*; Antioxidants/pharmacology; Angiogenesis Inhibitors/pharmacology; Tocotrienols/pharmacology*
  11. Clinical and therapeutic predictors of disease outcomes in AQP4-IgG+ neuromyelitis optica spectrum disorder
    Kunchok A, Malpas C, Nytrova P, Havrdova EK, Alroughani R, Terzi M, et al.
    Mult Scler Relat Disord, 2020 Feb;38:101868.
    PMID: 31877445 DOI: 10.1016/j.msard.2019.101868
    BACKGROUND: Aquaporin-4-IgG positive (AQP4-IgG+) Neuromyelitis Optica Spectrum Disorder (NMOSD) is an uncommon central nervous system autoimmune disorder. Disease outcomes in AQP4-IgG+NMOSD are typically measured by relapse rate and disability. Using the MSBase, a multi-centre international registry, we aimed to examine the impact immunosuppressive therapies and patient characteristics as predictors of disease outcome measures in AQP4-IgG+NMOSD.

    METHOD: This MSBase cohort study of AQP4-IgG+NMOSD patients examined modifiers of relapse in a multivariable proportional hazards model and expanded disability status score (EDSS) using a mixed effects model.

    RESULTS: 206 AQP4-IgG+ patients were included (median follow-up 3.7 years). Age (hazard ratio [HR] = 0.82 per decade, p = 0.001), brainstem onset (HR = 0.45, p = 0.009), azathioprine (HR = 0.46, p<0.001) and mycophenolate mofetil (HR = 0.09, p = 0.012) were associated with a reduced risk of relapse. A greater EDSS was associated with age (β = 0.45 (per decade), p<0.001) and disease duration (β = 0.07 per year, p<0.001). A slower increase in EDSS was associated with azathioprine (β = -0.48, p<0.001), mycophenolate mofetil (β = -0.69, p = 0.04) and rituximab (β = -0.35, p = 0.024).

    INTERPRETATION: This study has demonstrated that azathioprine and mycophenolate mofetil reduce the risk of relapses and disability progression is modified by azathioprine, mycophenolate mofetil and rituximab. Age and disease duration were the only patient characteristics that modified the risk of relapse and disability in our cohort.

    Matched MeSH terms: Rituximab/pharmacology; Azathioprine/pharmacology; Immunologic Factors/pharmacology*; Mycophenolic Acid/pharmacology
  12. Radical scavenging activity of lipophilized products from transesterification of flaxseed oil with cinnamic acid or ferulic acid
    Choo WS, Birch EJ, Stewart I
    Lipids, 2009 Sep;44(9):807-15.
    PMID: 19727883 DOI: 10.1007/s11745-009-3334-2
    Lipase-catalyzed transesterification of flaxseed oil with cinnamic acid (CA) or ferulic acid (FA) using an immobilized lipase from Candida antarctica (E.C. 3.1.1.3) was conducted to evaluate whether the lipophilized products provided enhanced antioxidant activity in the oil. Lipase-catalyzed transesterification of flaxseed oil with CA or FA produced a variety of lipophilized products (identified using ESI-MS-MS) such as monocinnamoyl/feruloyl-diacylglycerol, dicinnamoyl-monoacylglycerol and monocinnamoyl-monoacylglycerol. The free radical scavenging activity of the lipophilized products of lipase-catalyzed transesterification of flaxseed oil with CA or FA toward 2,2-diphenyl-1-picrylhydrazyl radical (DPPH.) were both examined in ethanol and ethyl acetate. The polarity of the solvents proved important in determining the radical scavenging activity of the substrates. Unesterified FA showed the highest free radical scavenging activity among all substrates tested while CA had negligible activity. The esterification of CA or FA with flaxseed oil resulted in significant increase and decrease in the radical scavenging activity compared with the native phenolic acid, respectively. Based on the ratio of a substrate to DPPH. concentration, lipophilized FA was a much more efficient free radical scavenger compared to lipophilized CA and was able to provide enhanced antioxidant activity in the flaxseed oil. Lipophilized cinnamic acid did not provide enhanced radical scavenging activity in the flaxseed oil as the presence of natural hydrophilic antioxidants in the oil had much greater radical scavenging activity.
    Matched MeSH terms: Cinnamates/pharmacology*; Coumaric Acids/pharmacology*; Linseed Oil/pharmacology*; Free Radical Scavengers/pharmacology*
  13. Fulltext Targeted Isolation of Anti-Trypanosomal Naphthofuran-Quinone Compounds from the Mangrove Plant Avicennia lanata
    Mazlan NW, Clements C, Edrada-Ebel R
    Mar Drugs, 2020 Dec 21;18(12).
    PMID: 33371387 DOI: 10.3390/md18120661
    The discovery of new secondary metabolites from natural origins has become more challenging in natural products research. Different approaches have been applied to target the isolation of new bioactive metabolites from plant extracts. In this study, bioactive natural products were isolated from the crude organic extract of the mangrove plant Avicennia lanata collected from the east coast of Peninsular Malaysia in the Setiu Wetlands, Terengganu, using HRESI-LCMS-based metabolomics-guided isolation and fractionation. Isolation work on the crude extract A. lanata used high-throughput chromatographic techniques to give two new naphthofuranquinone derivatives, hydroxyavicenol C (1) and glycosemiquinone (2), along with the known compounds avicenol C (3), avicequinone C (4), glycoquinone (5), taraxerone (6), taraxerol (7), β-sitosterol (8) and stigmasterol (9). The elucidation and identification of the targeted bioactive compounds used 1D and 2D-NMR and mass spectrometry. Except for 6-9, all isolated naphthoquinone compounds (1-5) from the mangrove plant A. lanata showed significant anti-trypanosomal activity on Trypanosoma brucei brucei with MIC values of 3.12-12.5 μM. Preliminary cytotoxicity screening against normal prostate cells (PNT2A) was also performed. All compounds exhibited low cytotoxicity, with compounds 3 and 4 showing moderate cytotoxicity of 78.3% and 68.6% of the control values at 100 μg/mL, respectively.
    Matched MeSH terms: Antiprotozoal Agents/pharmacology; Furans/pharmacology; Naphthoquinones/pharmacology; Plant Extracts/pharmacology
  14. Resistant hypertension during antituberculosis treatment: how is rifampicin implicated?
    Lee SL, Lim WJ, Chai ST
    Med J Malaysia, 2020 09;75(5):591-593.
    PMID: 32918434
    A 67-year-old mental institute resident was treated for smear-positive pulmonary tuberculosis. His background history included chronic essential hypertension which was well-controlled with amlodipine 10mg daily. However, his blood pressure became suboptimal one week into antitubercular treatment, necessitating escalation of antihypertensive therapy up to six medications. Following completion of antitubercular treatment, his blood pressure improved markedly. The number of antihypertensives was able to be reduced to only two after a month. We postulate that rifampicin has attenuated the therapeutic effect of amlodipine via potent induction of hepatic CYP3A4 but the failure to control the blood pressure even with medications unrelated to cytochrome P450 pathways raises the spectre of an additional interaction.
    Matched MeSH terms: Antibiotics, Antitubercular/pharmacology*; Antihypertensive Agents/pharmacology*; Rifampin/pharmacology*; Amlodipine/pharmacology
  15. Fulltext PLGA nanoparticles loaded with Gallic acid- a constituent of Leea indica against Acanthamoeba triangularis
    Mahboob T, Nawaz M, de Lourdes Pereira M, Tian-Chye T, Samudi C, Sekaran SD, et al.
    Sci Rep, 2020 06 02;10(1):8954.
    PMID: 32488154 DOI: 10.1038/s41598-020-65728-0
    Acanthamoeba, a genus that contains at least 24 species of free-living protozoa, is ubiquitous in nature. Successful treatment of Acanthamoeba infections is always very difficult and not always effective. More effective drugs must be developed, and medicinal plants may have a pivotal part in the future of drug discovery. Our research focused on investigating the in vitro anti- acanthamoebic potential of Leea indica and its constituent gallic acid in different concentrations. Water and butanol fractions exhibited significant amoebicidal activity against trophozoites and cysts. Gallic acid (100 µg/mL) revealed 83% inhibition of trophozoites and 69% inhibition of cysts. The butanol fraction induced apoptosis in trophozoites, which was observed using tunnel assay. The cytotoxicity of the fractions and gallic acid was investigated against MRC-5 and no adverse effects were observed. Gallic acid was successfully loaded within poly (D,L-lactide-co-glycolide) (PLGA) nanoparticles with 82.86% encapsulation efficiency, while gallic acid showed 98.24% in vitro release at 48 hours. Moreover, the gallic acid encapsulated in the PLGA nanoparticles exhibited 90% inhibition against trophozoites. In addition, gallic acid encapsulated nanoparticles showed reduced cytotoxicity towards MRC-5 compared to gallic acid, which evidenced that natural product nanoencapsulation in polymeric nanoparticles could play an important role in the delivery of natural products.
    Matched MeSH terms: Amebicides/pharmacology; Gallic Acid/pharmacology*; Plant Extracts/pharmacology; Polyglycolic Acid/pharmacology
  16. 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: Antineoplastic Agents/pharmacology; Antioxidants/pharmacology; Peptides/pharmacology; Peroxiredoxins/pharmacology
  17. Phenotypic and genetic characterization of multidrug-resistant Staphylococcus aureus in the tropics of Southeast Asia
    Zulkeflle SNM, Yusaimi YA, Sugiura N, Iwamoto K, Goto M, Utsumi M, et al.
    Microbiology (Reading), 2016 12;162(12):2064-2074.
    PMID: 27902427 DOI: 10.1099/mic.0.000392
    Antibiotic resistance has become a major public health problem throughout the world. The presence of antibiotic-resistant bacteria such as Staphylococcus aureus and antibiotic resistance genes (ARGs) in hospital wastewater is a cause for great concern today. In this study, 276 Staph. aureus isolates were recovered from hospital wastewater samples in Malaysia. All of the isolates were screened for susceptibility to nine different classes of antibiotics: ampicillin, ciprofloxacin, gentamicin, kanamycin, erythromycin, vancomycin, trimethoprim and sulfamethoxazole, chloramphenicol, tetracycline and nalidixic acid. Screening tests showed that 100 % of Staph.aureus isolates exhibited resistance against kanamycin, vancomycin, trimethoprim and sulfamethoxazole and nalidixic acid. Additionally, 91, 87, 50, 43, 11 and 8.7 % of isolates showed resistance against erythromycin, gentamicin, ciprofloxacin, ampicillin, chloramphenicol and tetracycline, respectively. Based on these results, 100 % of isolates demonstrated multidrug-resistant (MDR) characteristics, displaying resistance against more than three classes of antibiotics. Of 276 isolates, nine exhibited resistance to more than nine classes of tested antibiotics; these were selected for antibiotic susceptibility testing and examined for the presence of conserved ARGs. Interestingly, a high percentage of the selected MDR Staph.aureus isolates did not contain conserved ARGs. These results indicate that non-conserved MDR gene elements may have already spread into the environment in the tropics of Southeast Asia, and unique resistance mechanisms against several antibiotics may have evolved due to stable, moderate temperatures that support growth of bacteria throughout the year.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology*; Ciprofloxacin/pharmacology; Gentamicins/pharmacology; Vancomycin/pharmacology
  18. Fulltext Anticorrosive and Microbial Inhibition Performance of a Coating Loaded with Andrographis paniculata on Stainless Steel in Seawater
    Kamaruzzaman WMIWM, Fekeri MFM, Nasir NAM, Hamidi NASM, Baharom MZ, Adnan A, et al.
    Molecules, 2021 Jun 03;26(11).
    PMID: 34205014 DOI: 10.3390/molecules26113379
    With the trend for green technology, the study focused on utilizing a forgotten herb to produce an eco-friendly coating. Andrographis paniculata or the kalmegh leaves extract (KLE) has been investigated for its abilities in retarding the corrosion process due to its excellent anti-oxidative and antimicrobial properties. Here, KLE was employed as a novel additive in coatings and formulations were made by varying its wt%: 0, 3, 6, 9, and 12. These were applied to stainless steel 316L immersed in seawater for up to 50 days. The samples were characterized and analyzed to measure effectiveness of inhibition of corrosion and microbial growth. The best concentration was revealed to be 6 wt% KLE; it exhibited the highest performance in improving the ionic resistance of the coating and reducing the growth of bacteria.
    Matched MeSH terms: Anti-Infective Agents/pharmacology; Antioxidants/pharmacology; Stainless Steel/pharmacology*; Coated Materials, Biocompatible/pharmacology*
  19. Preparation and photodynamic bactericidal effects of curcumin-β-cyclodextrin complex
    Lai D, Zhou A, Tan BK, Tang Y, Sarah Hamzah S, Zhang Z, et al.
    Food Chem, 2021 Nov 01;361:130117.
    PMID: 34058659 DOI: 10.1016/j.foodchem.2021.130117
    To overcome the poor water solubility of curcumin, a curcumin-β-cyclodextrin (Cur-β-CD) complex was prepared as a novel photosensitizer. Fourier-transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) were used to verify the formation of Cur-β-CD. Furthermore, the ROS generation capacity and photodynamic bactericidal effect were measured to confirm this Cur-β-CD complex kept photodynamic activity of curcumin. The result showed Cur-β-CD could effectively generate ROS upon blue-light irradiation. The plate count assay demonstrated Cur-β-CD complex possess desirable photodynamic antibacterial effect against food-borne pathogens including Staphylococcus aureus, Listeria monocytogenes and Escherichia coli. The cell morphology determined by scanning electron microscope (SEM) and transmission electron microscope (TEM) showed Cur-β-CD could cause cell deformation, surface collapse and cell structure damage of the bacteria, resulting in the leakage of cytoplasmic; while agarose gel electrophoresis and SDS-PAGE further illustrated the inactivation mechanisms by Cur-β-CD involve bacterial DNA damage and protein degradation.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology; Curcumin/pharmacology; Photosensitizing Agents/pharmacology; beta-Cyclodextrins/pharmacology
  20. Fulltext Novel Polymyxin Combination with the Antiretroviral Zidovudine Exerts Synergistic Killing against NDM-Producing Multidrug-Resistant Klebsiella pneumoniae
    Lin YW, Abdul Rahim N, Zhao J, Han ML, Yu HH, Wickremasinghe H, et al.
    Antimicrob Agents Chemother, 2019 04;63(4).
    PMID: 30670431 DOI: 10.1128/AAC.02176-18
    Polymyxins are used as a last-line therapy against multidrug-resistant (MDR) New Delhi metallo-β-lactamase (NDM)-producing Klebsiella pneumoniae However, polymyxin resistance can emerge with monotherapy; therefore, novel strategies are urgently needed to minimize the resistance and maintain their clinical utility. This study aimed to investigate the pharmacodynamics of polymyxin B in combination with the antiretroviral drug zidovudine against K. pneumoniae Three isolates were evaluated in static time-kill studies (0 to 64 mg/liter) over 48 h. An in vitro one-compartment pharmacokinetic/pharmacodynamic (PK/PD) model (IVM) was used to simulate humanized dosage regimens of polymyxin B (4 mg/liter as continuous infusion) and zidovudine (as bolus dose thrice daily to achieve maximum concentration of drug in broth [Cmax] of 6 mg/liter) against K. pneumoniae BM1 over 72 h. The antimicrobial synergy of the combination was further evaluated in a murine thigh infection model against K. pneumoniae 02. In the static time-kill studies, polymyxin B monotherapy produced rapid and extensive killing against all three isolates followed by extensive regrowth, whereas zidovudine produced modest killing followed by significant regrowth at 24 h. Polymyxin B in combination with zidovudine significantly enhanced the antimicrobial activity (≥4 log10 CFU/ml) and minimized bacterial regrowth. In the IVM, the combination was synergistic and the total bacterial loads were below the limit of detection for up to 72 h. In the murine thigh infection model, the bacterial burden at 24 h in the combination group was ≥3 log10 CFU/thigh lower than each monotherapy against K. pneumoniae 02. Overall, the polymyxin B-zidovudine combination demonstrates superior antimicrobial efficacy and minimized emergence of resistance to polymyxins.
    Matched MeSH terms: Anti-Bacterial Agents/pharmacology*; Polymyxin B/pharmacology*; Zidovudine/pharmacology*; Anti-Retroviral Agents/pharmacology*
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