Displaying publications 1681 - 1700 of 4716 in total

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  1. Report: Antibacterial activity of a peptide derived from HIV-1 MN strain gp41 envelope glycoprotein against methicillin-resistant Staphylococcus aureus
    Teow SY, Ali SA
    Pak J Pharm Sci, 2016 Nov;29(6):2119-2124.
    PMID: 28375134
    Peptides derived from HIV-1 transmembrane proteins have been extensively studied for antimicrobial activities, and they are known as antimicrobial peptides (AMPs). These AMPs have also been reported to potently combat the drug-resistant microbes. In this study, we demonstrated that peptide #6383 originated from HIV-1 MN strain membrane-spanning domain of gp41 was active (2-log reductions) at 100βg/mL (56.5βM) against methicillin-resistant Staphylococcus aureus (MRSA) in 10% and 50% human plasma-supplemented phosphate buffered saline (PBS). The activity was further enhanced (3-log reductions) in the presence of 5% human serum albumin (HSA) alone. All bactericidal activities were achieved within 6 hours. At 100μg/mL, the peptide showed only 13% toxicity against human erythrocytes. This peptide can serve as an attractive template for a design of a novel peptide antibiotic against drug-resistant bacteria. By sequence-specific engineering or modifications, we anticipated that the bactericidal activity and the reduced toxicity against human erythrocytes will be improved.
    Matched MeSH terms: Anti-Bacterial Agents/isolation & purification; Peptide Fragments/isolation & purification; HIV Envelope Protein gp41/isolation & purification
  2. Effects of tocotrienol from Bixa orellana (annatto) on bone histomorphometry in a male osteoporosis model induced by buserelin
    Mohamad NV, Soelaiman IN, Chin KY
    Biomed Pharmacother, 2018 Jul;103:453-462.
    PMID: 29674281 DOI: 10.1016/j.biopha.2018.04.083
    INTRODUCTION: Osteoporosis is a debilitating skeletal side effect of androgen deprivation therapy based on gonadotropin-releasing hormone (GnRH) agonist in men. Tocotrienol from Bixa orellana (annatto) has been demonstrated to offer protection against osteoporosis by exerting anabolic effects on bone. Thus, it may prevent osteoporosis among GnRH agonist users.

    OBJECTIVE: This study aimed to determine the effectiveness of annatto-tocotrienol on the bone turnover markers and bone histomorphometry in a model of male osteoporosis induced by buserelin (a GnRH agonist).

    METHODS: Forty-six three-months-old male Sprague-Dawley rats (three months old; 300-350 g) were randomly divided into six groups. The baseline control group (n = 6) was sacrificed at the onset of the study. The normal control group (n = 8) received corn oil (the vehicle of tocotrienol) orally daily and normal saline (the vehicle of buserelin) subcutaneously daily. The buserelin control (n = 8) received corn oil orally daily and subcutaneous buserelin injection 75 μg/kg/day daily. The calcium control (n = 8) received 1% calcium in drinking water and subcutaneous buserelin injection 75 μg/kg/day. The remaining rats were treated with two different treatments, i.e., (1) oral annatto tocotrienol at 60 mg/kg/day plus subcutaneous buserelin injection 75 μg/kg/day (n = 8); (2) oral annatto tocotrienol at 100 mg/kg/day plus subcutaneous buserelin injection 75 μg/kg/day (n = 8). The rats were injected with calcein twice before being sacrificed to label the bones. The rats were euthanized, and their blood and right femur were harvested at the end of the treatment for bone turnover markers and bone histomorphometry examination.

    RESULTS: Both serum osteocalcin and C-telopeptide of type 1 collagen were not significantly different between treated groups and buserelin control (P > 0.05). The buserelin control group had a significantly lower bone volume and higher eroded surface compared with the normal control group (P 

    Matched MeSH terms: Carotenoids/isolation & purification; Plant Extracts/isolation & purification; Tocotrienols/isolation & purification
  3. Development of nanoparticle-assisted PCR assay in the rapid detection of brain-eating amoebae
    Gabriel S, Rasheed AK, Siddiqui R, Appaturi JN, Fen LB, Khan NA
    Parasitol Res, 2018 Jun;117(6):1801-1811.
    PMID: 29675682 DOI: 10.1007/s00436-018-5864-0
    Brain-eating amoebae (Acanthamoeba spp., Balamuthia mandrillaris, Naegleria fowleri) have gained increasing attention owing to their capacity to produce severe human and animal infections involving the brain. Early detection is a pre-requisite in successful prognosis. Here, we developed a nanoPCR assay for the rapid detection of brain-eating amoebae using various nanoparticles. Graphene oxide, copper and alumina nanoparticles used in this study were characterized using Raman spectroscopy measurements through excitation with a He-Ne laser, while powder X-ray diffraction patterns were taken on a PANanalytical, X'Pert HighScore diffractometer and the morphology of the materials was confirmed using high-resolution transmission electron microscopy (HRTEM). Using nanoparticle-assisted PCR, the results revealed that graphene oxide, copper oxide and alumina nanoparticles significantly enhanced PCR efficiency in the detection of pathogenic free-living amoebae using genus-specific probes. The optimal concentration of graphene oxide, copper oxide and alumina nanoparticles for Acanthamoeba spp. was determined at 0.4, 0.04 and 0.4 μg per mL respectively. For B. mandrillaris, the optimal concentration was determined at 0.4 μg per mL for graphene oxide, copper oxide and alumina nanoparticles, and for Naegleria, the optimal concentration was 0.04, 4.0 and 0.04 μg per mL respectively. Moreover, combinations of these nanoparticles proved to further enhance PCR efficiency. The addition of metal oxide nanoparticles leads to excellent surface effect, while thermal conductivity property of the nanoparticles enhances PCR productivity. These findings suggest that nanoPCR assay has tremendous potential in the clinical diagnosis of parasitic infections as well as for studying epidemiology and pathology and environmental monitoring of other microbes.
    Matched MeSH terms: Acanthamoeba/isolation & purification; Naegleria fowleri/isolation & purification; Balamuthia mandrillaris/isolation & purification
  4. Antiatherogenic Potential of Extracts from the Gray Oyster Medicinal Mushroom, Pleurotus pulmonarius (Agaricomycetes), In Vitro
    Abidin MHZ, Abdullah N, Abidin NZ
    Int J Med Mushrooms, 2018;20(3):283-290.
    PMID: 29717672 DOI: 10.1615/IntJMedMushrooms.2018025821
    This study evaluates the in vitro inhibition of angiotensin-converting enzyme (ACE) and 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA) by Pleurotus pulmonarius extracts. The protective effect on the endothelial membrane against oxidative stress through the protection of nitric oxide bioavailability, as well as inhibition of endocan expression, was evaluated using human aortic endothelial cells (HAECs). Crude cold aqueous extract exhibited the most potent inhibitory activities against ACE and HMG-CoA reductase, with 61.79% and 44.30% inhibition, respectively. It also protected the bioavailability of NO released by HAECs, with 84.88% cell viability. The crude hot water extract was the most potent in inhibiting endocan expression, with 18.61% inhibition.
    Matched MeSH terms: Angiotensin-Converting Enzyme Inhibitors/isolation & purification; Hydroxymethylglutaryl-CoA Reductase Inhibitors/isolation & purification; Complex Mixtures/isolation & purification
  5. Carbon nanotube-based aptasensor for sensitive electrochemical detection of whole-cell Salmonella
    Hasan MR, Pulingam T, Appaturi JN, Zifruddin AN, Teh SJ, Lim TW, et al.
    Anal Biochem, 2018 08 01;554:34-43.
    PMID: 29870692 DOI: 10.1016/j.ab.2018.06.001
    In this study, an amino-modified aptasensor using multi-walled carbon nanotubes (MWCNTs)-deposited ITO electrode was prepared and evaluated for the detection of pathogenic Salmonella bacteria. An amino-modified aptamer (ssDNA) which binds selectively to whole-cell Salmonella was immobilised on the COOH-rich MWCNTs to produce the ssDNA/MWCNT/ITO electrode. The morphology of the MWCNT before and after interaction with the aptamers were observed using scanning electron microscopy (SEM). Cyclic voltammetry and electrochemical impedance spectroscopy techniques were used to investigate the electrochemical properties and conductivity of the aptasensor. The results showed that the impedance measured at the ssDNA/MWCNT/ITO electrode surface increased after exposure to Salmonella cells, which indicated successful binding of Salmonella on the aptamer-functionalised surface. The developed ssDNA/MWCNT/ITO aptasensor was stable and maintained linearity when the scan rate was increased from 10 mV s-1 to 90 mV s-1. The detection limit of the ssDNA/MWCNT/ITO aptasensor, determined from the sensitivity analysis, was found to be 5.5 × 101 cfu mL-1 and 6.7 × 101 cfu mL-1 for S. Enteritidis and S. Typhimurium, respectively. The specificity test demonstrated that Salmonella bound specifically to the ssDNA/MWCNT/ITO aptasensor surface, when compared with non-Salmonella spp. The prepared aptasensor was successfully applied for the detection of Salmonella in food samples.
    Matched MeSH terms: Salmonella/isolation & purification*; Salmonella enteritidis/isolation & purification; Salmonella typhimurium/isolation & purification
  6. Fulltext Isolation, Purification, and Characterization of Five Active Diketopiperazine Derivatives from Endophytic Streptomyces SUK 25 with Antimicrobial and Cytotoxic Activities
    Alshaibani M, Zin NM, Jalil J, Sidik N, Ahmad SJ, Kamal N, et al.
    J Microbiol Biotechnol, 2017 07 28;27(7):1249-1256.
    PMID: 28535606 DOI: 10.4014/jmb.1608.08032
    In our search for new sources of bioactive secondary metabolites from Streptomyces sp., the ethyl acetate extracts from endophytic Streptomyces SUK 25 afforded five active diketopiperazine (DKP) compounds. The aim of this study was to characterize the bioactive compounds isolated from endophytic Streptomyces SUK 25 and evaluate their bioactivity against multiple drug resistance (MDR) bacteria such as Enterococcus raffinosus, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, and Enterobacter spp., and their cytotoxic activities against the human hepatoma (HepaRG) cell line. The production of secondary metabolites by this strain was optimized through Thornton's medium. Isolation, purification, and identification of the bioactive compounds were carried out using high-performance liquid chromatography, high-resolution mass liquid chromatography-mass spectrometry, Fourier transform infrared spectroscopy, and nuclear magnetic resonance, and cryopreserved HepaRG cells were selected to test the cytotoxicity. The results showed that endophytic Streptomyces SUK 25 produces four active DKP compounds and an acetamide derivative, which were elucidated as cyclo-(L-Val-L-Pro), cyclo-(L-Leu-L-Pro), cyclo-(L-Phe-L-Pro), cyclo-(L-Val-L-Phe), and N-(7-hydroxy-6-methyl-octyl)-acetamide. These active compounds exhibited activity against methicillin-resistant S. aureus ATCC 43300 and Enterococcus raffinosus, with low toxicity against human hepatoma HepaRG cells. Endophytic Streptomyces SUK 25 has the ability to produce DKP derivatives biologically active against some MDR bacteria with relatively low toxicity against HepaRG cells line.
    Matched MeSH terms: Cytotoxins/isolation & purification; Peptides, Cyclic/isolation & purification; Diketopiperazines/isolation & purification*
  7. Proteomics analysis of latex from Hevea brasiliensis (clone RRIM 600)
    Habib MA, Yuen GC, Othman F, Zainudin NN, Latiff AA, Ismail MN
    Biochem. Cell Biol., 2017 04;95(2):232-242.
    PMID: 28177774 DOI: 10.1139/bcb-2016-0144
    The natural rubber latex extracted from the bark of Hevea brasiliensis plays various important roles in today's modern society. Following ultracentrifugation, the latex can be separated into 3 layers: C-serum, lutoids, and rubber particles. Previous studies have shown that a large number of proteins are present in these 3 layers. However, a complete proteome for this important plant is still unavailable. Protein sequences have been recently translated from the completed draft genome database of H. brasiliensis, leading to the creation of annotated protein databases of the following H. brasiliensis biosynthetic pathways: photosynthesis, latex allergens, rubberwood formation, latex biosynthesis, and disease resistance. This research was conducted to identify the proteins contained within the latex by way of de novo sequencing from mass spectral data obtained from the 3 layers of the latex. Peptides from these proteins were fragmented using collision-induced dissociation, higher-energy collisional dissociation, and electron-transfer dissociation activation methods. A large percentage of proteins from the biosynthetic pathways (63% to 100%) were successfully identified. In addition, a total of 1839 unique proteins were identified from the whole translated draft genome database (AnnHBM).
    Matched MeSH terms: Allergens/isolation & purification*; Plant Proteins/isolation & purification*; Proteome/isolation & purification*
  8. Fulltext Antifilarial and Antibiotic Activities of Methanolic Extracts of Melaleuca cajuputi Flowers
    Al-Abd NM, Nor ZM, Mansor M, Hasan MS, Kassim M
    Korean J Parasitol, 2016 Jun;54(3):273-80.
    PMID: 27417081 DOI: 10.3347/kjp.2016.54.3.273
    We evaluated the activity of methanolic extracts of Melaleuca cajuputi flowers against the filarial worm Brugia pahangi and its bacterial endosymbiont Wolbachia. Anti-Wolbachia activity was measured in worms and in Aedes albopictus Aa23 cells by PCR, electron microscopy, and other biological assays. In particular, microfilarial release, worm motility, and viability were determined. M. cajuputi flower extracts were found to significantly reduce Wolbachia endosymbionts in Aa23 cells, Wolbachia surface protein, and microfilarial release, as well as the viability and motility of adult worms. Anti-Wolbachia activity was further confirmed by observation of degraded and phagocytized Wolbachia in worms treated with the flower extracts. The data provided in vitro and in vivo evidence that M. cajuputi flower extracts inhibit Wolbachia, an activity that may be exploited as an alternative strategy to treat human lymphatic filariasis.
    Matched MeSH terms: Anti-Bacterial Agents/isolation & purification; Filaricides/isolation & purification; Plant Extracts/isolation & purification
  9. Biofilm inhibiting activity of betacyanins from red pitahaya (Hylocereus polyrhizus) and red spinach (Amaranthus dubius) against Staphylococcus aureus and Pseudomonas aeruginosa biofilms
    Yong YY, Dykes G, Lee SM, Choo WS
    J Appl Microbiol, 2019 Jan;126(1):68-78.
    PMID: 30153380 DOI: 10.1111/jam.14091
    AIMS: To investigate the biofilm inhibitory activity of betacyanins from red pitahaya (Hylocereus polyrhizus) and red spinach (Amaranthus dubius) against Staphylococcus aureus and Pseudomonas aeruginosa biofilms.

    METHODS AND RESULTS: The pulp of red pitahaya and the leaves of red spinach were extracted using methanol followed by subfractionation to obtain betacyanin fraction. The anti-biofilm activity was examined using broth microdilution assay on polystyrene surfaces and expressed as minimum biofilm inhibitory concentration (MBIC). The betacyanin fraction from red spinach showed better anti-biofilm activity (MBIC: 0·313-1·25 mg ml-1 ) against five Staph. aureus strains while the betacyanin fraction from red pitahaya showed better anti-biofilm activity (MBIC: 0·313-0·625 mg ml-1 ) against four P. aeruginosa strains. Both betacyanin fraction significantly reduced hydrophobicity of Staph. aureus and P. aeruginosa strains. Numbers of Staph. aureus and P. aeruginosa attached to polystyrene were also reduced without affecting their cell viability.

    CONCLUSION: Betacyanins can act as anti-biofilm agents against the initial step of biofilm formation, particularly on a hydrophobic surface like polystyrene.

    SIGNIFICANCE AND IMPACT OF THE STUDY: This study is the first to investigate the use of betacyanin as a biofilm inhibitory agent. Betacyanin could potentially be used to reduce the risk of biofilm-associated infections.

    Matched MeSH terms: Anti-Bacterial Agents/isolation & purification; Plant Extracts/isolation & purification; Betacyanins/isolation & purification
  10. Fulltext Diversity of endocervical microbiota associated with genital Chlamydia trachomatis infection and infertility among women visiting obstetrics and gynecology clinics in Malaysia
    Cheong HC, Yap PSX, Chong CW, Cheok YY, Lee CYQ, Tan GMY, et al.
    PLoS One, 2019;14(11):e0224658.
    PMID: 31738795 DOI: 10.1371/journal.pone.0224658
    The cervical microbiota constitutes an important protective barrier against the invasion of pathogenic microorganisms. A disruption of microbiota within the cervical milieu has been suggested to be a driving factor of sexually transmitted infections. These include Chlamydia trachomatis which frequently causes serious reproductive sequelae such as infertility in women. In this study, we profiled the cervical microbial composition of a population of 70 reproductive-age Malaysian women; among which 40 (57.1%) were diagnosed with genital C. trachomatis infection, and 30 (42.8%) without C. trachomatis infection. Our findings showed a distinct compositional difference between the cervical microbiota of C. trachomatis-infected subjects and subjects without C. trachomatis infection. Specifically, significant elevations of mostly strict and facultative anaerobes such as Streptococcus, Megasphaera, Prevotella, and Veillonella in the cervical microbiota of C. trachomatis-positive women were detected. The results from the current study highlights an interaction of C. trachomatis with the environmental microbiome in the endocervical region.
    Matched MeSH terms: Bacteria, Anaerobic/isolation & purification; Chlamydia trachomatis/isolation & purification*; DNA, Bacterial/isolation & purification
  11. Isolation and identification of salt-tolerant plant-growth-promoting rhizobacteria and their application for rice cultivation under salt stress
    Sultana S, Paul SC, Parveen S, Alam S, Rahman N, Jannat B, et al.
    Can J Microbiol, 2020 Feb;66(2):144-160.
    PMID: 31714812 DOI: 10.1139/cjm-2019-0323
    Growth and productivity of rice are negatively affected by soil salinity. However, some salt-tolerant rhizosphere-inhabiting bacteria can improve salt resistance of plants, thereby augmenting plant growth and production. Here, we isolated a total of 53 plant-growth-promoting rhizobacteria (PGPR) from saline and non-saline areas in Bangladesh where electrical conductivity was measured as >7.45 and <1.80 dS/m, respectively. Bacteria isolated from saline areas were able to grow in a salt concentration of up to 2.60 mol/L, contrary to the isolates collected from non-saline areas that did not survive beyond 854 mmol/L. Among the salt-tolerant isolates, Bacillus aryabhattai, Achromobacter denitrificans, and Ochrobactrum intermedium, identified by comparing respective sequences of 16S rRNA using the NCBI GenBank, exhibited a higher amount of atmospheric nitrogen fixation, phosphate solubilization, and indoleacetic acid production at 200 mmol/L salt stress. Salt-tolerant isolates exhibited greater resistance to heavy metals and antibiotics, which could be due to the production of an exopolysaccharide layer outside the cell surface. Oryza sativa L. fertilized with B. aryabhattai MS3 and grown under 200 mmol/L salt stress was found to be favoured by enhanced expression of a set of at least four salt-responsive plant genes: BZ8, SOS1, GIG, and NHX1. Fertilization of rice with osmoprotectant-producing PGPR, therefore, could be a climate-change-preparedness strategy for coastal agriculture.
    Matched MeSH terms: Bacillus/isolation & purification; Ochrobactrum/isolation & purification; Achromobacter denitrificans/isolation & purification
  12. Screening for antihyperglycaemic activity in several local herbs of Malaysia
    Husen R, Pihie AH, Nallappan M
    J Ethnopharmacol, 2004 Dec;95(2-3):205-8.
    PMID: 15507337 DOI: 10.1016/j.jep.2004.07.004
    Screening of aqueous extract of Phyllantus niruri (PL), Zingiber zerumbet (ZG), Eurycoma longifolia (TA-a and TA-b) and Andrographis paniculata (AP) to determine their blood glucose lowering effect were conducted in normoglycaemic and Streptozotocin-induced hyperglycaemic rats. Significant reduction in blood glucose level at 52.90% was shown when hyperglycaemic rats were treated with 50 mg/kg body weight (BW) aqueous extract of AP. This effect is enhanced when freeze-dried material was used, where 6.25 mg/kg BW gave 61.81% reduction in blood glucose level. In the administration of TA-a and TA-b, positive results in hyperglyacaemic rats were only obtained when 150 mg/kg BW of the aqueous extract was used. No significant reduction in blood glucose level were shown in hyperglycaemic rats treated with PL and ZG at all concentrations used (50, 100 and 150 mg/kg BW). In normoglycaemic rats, no significant reduction was noted when all the same extracts were used.
    Matched MeSH terms: Hypoglycemic Agents/isolation & purification; Plant Extracts/isolation & purification; Plant Preparations/isolation & purification
  13. Antiplasmodial studies of Eurycoma longifolia Jack using the lactate dehydrogenase assay of Plasmodium falciparum
    Chan KL, Choo CY, Abdullah NR, Ismail Z
    J Ethnopharmacol, 2004 Jun;92(2-3):223-7.
    PMID: 15138004 DOI: 10.1016/j.jep.2004.02.025
    The roots of Eurycoma longifolia Jack have been used as traditional medicine to treat malaria. A systematic bioactivity-guided fractionation of this plant was conducted involving the determination of the effect of its various extracts and their chemical constituents on the lactate dehydrogenase activity of in vitro chloroquine-resistant Gombak A isolate and chloroquine-sensitive D10 strain of Plasmodium falciparum parasites. Their antiplasmodial activity was also compared with their known in vitro cytotoxicity against KB cells. Four quassinoids, eurycomanone (1), 13,21-dihydroeurycomanone (3), 13 alpha(21)-epoxyeurycomanone (4), eurycomalactone (6) and an alkaloid, 9-methoxycanthin-6-one (7), displayed higher antiplasmodial activity against Gombak A isolate but were less active against the D10 strain when compared with chloroquine. Amongst the compounds tested, 1 and 3 showed higher selectivity indices obtained for the cytotoxicity to antiplasmodial activity ratio than 14,15 beta-dihydroxyklaineanone (2), eurycomanol (5), 6 and 7.
    Matched MeSH terms: Antimalarials/isolation & purification; Plant Extracts/isolation & purification; Quassins/isolation & purification
  14. Derivatives of pheophorbide-a and pheophorbide-b from photocytotoxic Piper penangense extract
    Kamarulzaman FA, Shaari K, Ho AS, Lajis NH, Teo SH, Lee HB
    Chem Biodivers, 2011 Mar;8(3):494-502.
    PMID: 21404433 DOI: 10.1002/cbdv.201000341
    In our screening program for new photosensitizers from Malaysian biodiversity for photodynamic therapy (PDT) of cancer, MeOH extracts of ten terrestrial plants from Cameron Highlands in Pahang, Peninsular Malaysia, were tested. In a short-term 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, 20 μg/ml each of these extracts were incubated in a pro-myelocytic leukemia cell-line, HL60, with or without irradiation with 9.6 J/cm(2) of a broad spectrum light. Three samples, Labisia longistyla, Dichroa febrifuga, and Piper penangense, were photocytotoxic by having at least twofold lower cell viability when irradiated compared to the unirradiated assay. The extract of the leaves of Piper penangense, a shrub belonging to the family Piperaceae and widely distributed in the tropical and subtropical regions in the world, was subsequently subjected to bioassay-guided fractionation using standard chromatography methods. Eight derivatives of pheophorbide-a and -b were identified from the fractions that exhibited strong photocytotoxicity. By spectroscopic analysis, these compounds were identified as pheophorbide-a methyl ester (1), (R,S)-13(2) -hydroxypheophorbide-a methyl ester (2 and 3), pheophorbide-b methyl ester (4), 13(2) -hydroxypheophorbide-b methyl ester (5), 15(2) -hydroxylactone pheophorbide-a methyl ester (6), 15(2) -methoxylactone pheophorbide-a methyl ester (7), 15(2) -methoxylactone pheophorbide-b methyl ester (8).
    Matched MeSH terms: Antineoplastic Agents, Phytogenic/isolation & purification*; Chlorophyll/isolation & purification; Photosensitizing Agents/isolation & purification*
  15. Comparative X-ray and conformational analysis of a new crystal of 13α,21-dihydroeurycomanone with eurycomanone from Eurycoma longifolia and their anti-estrogenic activity using the uterotrophic assay
    Teh CH, Abdulghani M, Morita H, Shiro M, Hussin AH, Chan KL
    Planta Med, 2011 Jan;77(2):128-32.
    PMID: 20665368 DOI: 10.1055/s-0030-1250159
    13 α,21-Dihydroeurycomanone (1), a known quassinoid of Eurycoma longifolia Jack was recrystallized from chloroform into a novel crystal structure in space group P2 (1). Its X-ray data were compared with those of eurycomanone ( 2). Following intraperioneal injections at similar doses of 2.44 µmol/kg/day for 3 consecutive days, 2 displayed comparable potency with tamoxifen but was more potent than 1 in the anti-estrogenic effect against 17 α-ethynylestradiol (EE)-induced uterotrophy of immature rats.
    Matched MeSH terms: Estrogen Antagonists/isolation & purification; Plant Extracts/isolation & purification; Quassins/isolation & purification
  16. Diversity of microbiota associated with symptomatic and non-symptomatic bacterial wilt-diseased banana plants determined using 16S rRNA metagenome sequencing
    Suhaimi NSM, Goh SY, Ajam N, Othman RY, Chan KG, Thong KL
    World J Microbiol Biotechnol, 2017 Aug 21;33(9):168.
    PMID: 28828756 DOI: 10.1007/s11274-017-2336-0
    Banana is one of the most important fruits cultivated in Malaysia, and it provides many health benefits. However, bacterial wilt disease, which attacks bananas, inflicts major losses on the banana industry in Malaysia. To understand the complex interactions of the microbiota of bacterial wilt-diseased banana plants, we first determined the bacterial communities residing in the pseudostems of infected (symptomatic) and diseased-free (non-symptomatic) banana plants. We characterized the associated microorganisms using the targeted 16S rRNA metagenomics sequencing on the Illumina MiSeq platform. Taxonomic classifications revealed 17 and nine known bacterial phyla in the tissues of non-symptomatic and symptomatic plants, respectively. Cyanobacteria and Proteobacteria (accounted for more than 99% of the 16S rRNA gene fragments) were the two most abundant phyla in both plants. The five major genera found in both plant samples were Ralstonia, Sphingomonas, Methylobacterium, Flavobacterium, and Pseudomonas. Ralstonia was more abundant in symptomatic plant (59% out of the entire genera) as compared to those in the non-symptomatic plant (only 36%). Our data revealed that 102 bacterial genera were only assigned to the non-symptomatic plant. Overall, this study indicated that more diverse and abundant microbiota were associated with the non-symptomatic bacterial wilt-diseased banana plant as compared to the symptomatic plant. The higher diversity of endophytic microbiota in the non-symptomatic banana plant could be an indication of pathogen suppression which delayed or prevented the disease expression. This comparative study of the microbiota in the two plant conditions might provide caveats for potential biological control strategies.
    Matched MeSH terms: Cyanobacteria/isolation & purification; Bacteria/isolation & purification; Proteobacteria/isolation & purification
  17. Identification of α-tocopherol as a bioactive component of Dicranopteris linearis with disrupting property against preformed biofilm of Staphylococcus aureus
    Mawang CI, Lim YY, Ong KS, Muhamad A, Lee SM
    J Appl Microbiol, 2017 Nov;123(5):1148-1159.
    PMID: 28869803 DOI: 10.1111/jam.13578
    AIMS: The potential of Dicranopteris linearis leaves' extract and its bioactive components were investigated for the first time for its disrupting ability against Staphylococcus aureus biofilms.

    METHODS AND RESULTS: The leaves of D. linearis were subjected to sonication-assisted extraction using hexane (HEX), dichloromethane, ethyl acetate and methanol (MeOH). It was found that only the MeOH fraction exhibited antimicrobial activity using broth microdilution assay; while all four fractions do not exhibit biofilm inhibition activity against S. aureusATCC 6538P, S. aureusATCC 43300, S. aureusATCC 33591 and S. aureusATCC 29213 using crystal violet assay. Among the four fractions tested, only the HEX fraction showed biofilm disrupting ability, with 60-90% disruption activity at 5 mg ml-1against all four S. aureus strains tested. Bioassay-guided purification of the active fraction has led to the isolation of α-tocopherol. α-Tocopherol does not affect the cells within the biofilms but instead affects the biofilm matrix in order to disrupt S. aureus biofilms.

    CONCLUSIONS: α-Tocopherol was identified to be the bioactive component of D. linearis with disruption activity against S. aureus biofilm matrix.

    SIGNIFICANCE AND IMPACT OF THE STUDY: The use of α-tocopherol as a biofilm disruptive agent might potentially be useful to treat biofilm-associated infections in the future.

    Matched MeSH terms: Anti-Bacterial Agents/isolation & purification; Plant Extracts/isolation & purification; alpha-Tocopherol/isolation & purification
  18. Comparative nutritional and mycochemical contents, biological activities and LC/MS screening of tuber from new recipe cultivation technique with wild type tuber of tiger's milk mushroom of species Lignosus rhinocerus
    Jamil NAM, Rashid NMN, Hamid MHA, Rahmad N, Al-Obaidi JR
    World J Microbiol Biotechnol, 2017 Dec 04;34(1):1.
    PMID: 29204733 DOI: 10.1007/s11274-017-2385-4
    Tiger's milk mushroom is known for its valuable medicinal properties, especially the tuber part. However, wild tuber is very hard to obtain as it grows underground. This study first aimed to cultivate tiger's milk mushroom tuber through a cultivation technique, and second to compare nutritional and mycochemical contents, antioxidant and cytotoxic activities and compound screening of the cultivated tuber with the wild tuber. Results showed an increase in carbohydrate content by 45.81% and protein content by 123.68% in the cultivated tuber while fat content reduced by 13.04%. Cultivated tuber also showed an increase of up to 64.21% for total flavonoid-like compounds and 62.51% of total β-D-glucan compared to the wild tuber. The antioxidant activity of cultivated tuber and wild tuber was 760 and 840 µg mL-1, respectively. The cytotoxic activity of boiled water extract of cultivated tuber against a human lung cancer cell line (A549) was 65.50 ± 2.12 µg mL-1 and against a human breast cancer cell line (MCF7) was 19.35 ± 0.11 µg mL-1. β-D-glucan extract from the purification of boiled water extract of cultivated tuber showed cytotoxic activity at 57.78 ± 2.29 µg mL-1 against A549 and 33.50 ± 1.41 µg mL-1 against MCF7. However, the β-glucan extract from wild tuber did not show a cytotoxic effect against either the A549 or MCF7 cell lines. Also, neither of the extracts from cultivated tuber and wild tuber showed an effect against a normal cell line (MRC5). Compound profiling through by liquid chromatography mass spectrometry (LC/MS) showed the appearance of new compounds in the cultivated tuber. In conclusion, our cultivated tuber of tiger's milk mushroom using a new recipe cultivation technique showed improved nutrient and bioactive compound contents, and antioxidant and cytotoxic activities compared to the wild tuber. Further investigations are required to obtain a better quality of cultivated tuber.
    Matched MeSH terms: Antineoplastic Agents/isolation & purification*; Antioxidants/isolation & purification; Biological Products/isolation & purification*
  19. An in vitro study of the antifungal activity of Trichoderma virens 7b and a profile of its non-polar antifungal components released against Ganoderma boninense
    Angel LP, Yusof MT, Ismail IS, Ping BT, Mohamed Azni IN, Kamarudin NH, et al.
    J Microbiol, 2016 Nov;54(11):732-744.
    PMID: 27796927
    Ganoderma boninense is the causal agent of a devastating disease affecting oil palm in Southeast Asian countries. Basal stem rot (BSR) disease slowly rots the base of palms, which radically reduces productive lifespan of this lucrative crop. Previous reports have indicated the successful use of Trichoderma as biological control agent (BCA) against G. boninense and isolate T. virens 7b was selected based on its initial screening. This study attempts to decipher the mechanisms responsible for the inhibition of G. boninense by identifying and characterizing the chemical compounds as well as the physical mechanisms by T. virens 7b. Hexane extract of the isolate gave 62.60% ± 6.41 inhibition against G. boninense and observation under scanning electron microscope (SEM) detected severe mycelial deformation of the pathogen at the region of inhibition. Similar mycelia deformation of G. boninense was observed with a fungicide treatment, Benlate(®) indicating comparable fungicidal effect by T. virens 7b. Fraction 4 and 5 of hexane active fractions through preparative thin layer chromatography (P-TLC) was identified giving the best inhibition of the pathogen. These fractions comprised of ketones, alcohols, aldehydes, lactones, sesquiterpenes, monoterpenes, sulphides, and free fatty acids profiled through gas chromatography mass spectrometry detector (GC/MSD). A novel antifungal compound discovery of phenylethyl alcohol (PEA) by T. virens 7b is reported through this study. T. virens 7b also proved to be an active siderophore producer through chrome azurol S (CAS) agar assay. The study demonstrated the possible mechanisms involved and responsible in the successful inhibition of G. boninense.
    Matched MeSH terms: Antifungal Agents/isolation & purification; Phenylethyl Alcohol/isolation & purification; Biological Control Agents/isolation & purification
  20. Fulltext Anti-tumour promoting activity and antioxidant properties of girinimbine isolated from the stem bark of Murraya koenigii S
    Kok YY, Mooi LY, Ahmad K, Sukari MA, Mat N, Rahmani M, et al.
    Molecules, 2012 Apr 20;17(4):4651-60.
    PMID: 22522395 DOI: 10.3390/molecules17044651
    Girinimbine, a carbazole alkaloid isolated from the stem bark of Murraya koenigii was tested for the in vitro anti-tumour promoting and antioxidant activities. Anti-tumour promoting activity was determined by assaying the capability of this compound to inhibit the expression of early antigen of Epstein-Barr virus (EA-EBV) in Raji cells that was induced by the tumour promoter, phorbol 12-myristate 13-acetate. The concentration of this compound that gave an inhibition rate at fifty percent was 6.0 µg/mL and was not cytotoxic to the cells. Immunoblotting analysis of the expression of EA-EBV showed that girinimbine was able to suppress restricted early antigen (EA-R). However, diffused early antigen (EA-D) was partially suppressed when used at 32.0 µg/mL. Girinimbine exhibited a very strong antioxidant activity as compared to a-tocopherol and was able to inhibit superoxide generation in the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced differentiated premyelocytic HL-60 cells more than 95%, when treated with the compound at 5.3 and 26.3 µg/mL, respectively. However girinimbine failed to scavenge the stable diphenyl picryl hydrazyl (DPPH)-free radical.
    Matched MeSH terms: Alkaloids/isolation & purification; Antineoplastic Agents, Phytogenic/isolation & purification; Antioxidants/isolation & purification
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