Displaying publications 941 - 951 of 951 in total

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  1. Awang K, Ibrahim H, Rosmy Syamsir D, Mohtar M, Mat Ali R, Azah Mohamad Ali N
    Chem Biodivers, 2011 Apr;8(4):668-73.
    PMID: 21480512 DOI: 10.1002/cbdv.201000225
    The essential oils from the leaves and rhizomes of Alpinia pahangensis Ridl., collected from Pahang, Peninsular Malaysia, were obtained by hydrodistillation, and their chemical compositions were determined by GC and GC/MS analyses. The major components of the rhizome oil were γ-selinene (11.60%), β-pinene (10.87%), (E,E)-farnesyl acetate (8.65%), and α-terpineol (6.38%), while those of the leaf oil were β-pinene (39.61%), α-pinene (7.55%), and limonene (4.89%). The investigation of the antimicrobial activity of the essential oils using the broth microdilution technique revealed that the rhizome oil of A. pahangensis inhibited five Staphylococcus aureus strains with minimum inhibitory concentration (MIC) values between 0.08 and 0.31 μg/μl, and four selected fungi with MIC values between 1.25 and 2.50 μg/μl.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  2. Chua LS, Lau CH, Chew CY, Ismail NIM, Soontorngun N
    Phytomedicine, 2018 Jan 15;39:49-55.
    PMID: 29433683 DOI: 10.1016/j.phymed.2017.12.015
    BACKGROUND: Orthosiphon aristatus (Blume) Miq. is a medicinal herb which is traditionally used for the treatment of diabetes and kidney diseases in South East Asia. Previous studies reported higher concentration of antioxidative phytochemicals, especially rosmarinic acid (ester of caffeic acid) and other caffeic acid derivatives in this plant extract than the other herbs such as rosemary and sage which are usually used as raw materials to produce rosmarinic acid supplement in the market.

    PURPOSE: The phytochemical profile of O. aristatus was investigated at different storage durations for quality comparison.

    METHODS: The phytochemicals were extracted from the leaves and stems of O. aristatus using a reflux reactor. The extracts were examined for total phenolic and flavonoid contents, as well as their antioxidant capacities, in terms of radical scavenging, metal chelating and reducing power. The phytochemical profiles were also analyzed by unsupervised principal component analysis and hierarchical cluster analysis, in relation to the factor of storage at 4 °C for 5 weeks.

    RESULTS: The leaf extract was likely to have more phytochemicals than stem extract, particularly caffeic acid derivatives including glycosylated and alkylated caffeic acids. This explains higher ratio of total phenolic content to total flavonoid content with higher antioxidant capacities for the leaf extracts. Rosmarinic acid dimer and salvianolic acid B appeared to be the major constituents, possibly contributing to the previously reported pharmacological properties. However, the phytochemical profiles were found changing, even though the extracts were stored in the refrigerator (4 °C). The change was significantly observed at the fifth week based on the statistical pattern recognition technique.

    CONCLUSION: O. aristatus could be a promising source of rosmarinic acid and its dimer, as well as salvianolic acid B with remarkably antioxidant properties. The phytochemical profile was at least stable for a month stored at 4 °C. It is likely to be a good choice of herbal tea with comparable radical scavenging activity, but lower caffeine content than other tea samples.

    Matched MeSH terms: Tandem Mass Spectrometry
  3. Liew YK, Awang Hamat R, van Belkum A, Chong PP, Neela V
    Clin Vaccine Immunol, 2015 May;22(5):593-603.
    PMID: 25809633 DOI: 10.1128/CVI.00493-14
    The exoproteome of Staphylococcus aureus contains enzymes and virulence factors that are important for host adaptation. We investigated the exoprotein profiles and cytokine/chemokine responses obtained in three different S. aureus-host interaction scenarios by using two-dimensional gel electrophoresis (2-DGE) and two-dimensional immunoblotting (2D-IB) combined with tandem mass spectrometry (MS/MS) and cytometric bead array techniques. The scenarios included S. aureus bacteremia, skin and soft tissue infections (SSTIs), and healthy carriage. By the 2-DGE approach, 12 exoproteins (the chaperone protein DnaK, a phosphoglycerate kinase [Pgk], the chaperone GroEL, a multisensor hybrid histidine kinase, a 3-methyl-2-oxobutanoate hydroxymethyltransferase [PanB], cysteine synthase A, an N-acetyltransferase, four isoforms of elongation factor Tu [EF-Tu], and one signature protein spot that could not be reliably identified by MS/MS) were found to be consistently present in more than 50% of the bacteremia isolates, while none of the SSTI or healthy-carrier isolates showed any of these proteins. By the 2D-IB approach, we also identified five antigens (methionine aminopeptidase [MetAPs], exotoxin 15 [Set15], a peptidoglycan hydrolase [LytM], an alkyl hydroperoxide reductase [AhpC], and a haptoglobin-binding heme uptake protein [HarA]) specific for SSTI cases. Cytokine and chemokine production varied during the course of different infection types and carriage. Monokine induced by gamma interferon (MIG) was more highly stimulated in bacteremia patients than in SSTI patients and healthy carriers, especially during the acute phase of infection. MIG could therefore be further explored as a potential biomarker of bacteremia. In conclusion, 12 exoproteins from bacteremia isolates, MIG production, and five antigenic proteins identified during SSTIs should be further investigated for potential use as diagnostic markers.
    Matched MeSH terms: Tandem Mass Spectrometry
  4. Mangzira Kemung H, Tan LT, Chan KG, Ser HL, Law JW, Lee LH, et al.
    Molecules, 2020 Aug 03;25(15).
    PMID: 32756432 DOI: 10.3390/molecules25153545
    There is an urgent need to search for new antibiotics to counter the growing number of antibiotic-resistant bacterial strains, one of which is methicillin-resistant Staphylococcus aureus (MRSA). Herein, we report a Streptomyces sp. strain MUSC 125 from mangrove soil in Malaysia which was identified using 16S rRNA phylogenetic and phenotypic analysis. The methanolic extract of strain MUSC 125 showed anti-MRSA, anti-biofilm and antioxidant activities. Strain MUSC 125 was further screened for the presence of secondary metabolite biosynthetic genes. Our results indicated that both polyketide synthase (pks) gene clusters, pksI and pksII, were detected in strain MUSC 125 by PCR amplification. In addition, gas chromatography-mass spectroscopy (GC-MS) detected the presence of different chemicals in the methanolic extract. Based on the GC-MS analysis, eight known compounds were detected suggesting their contribution towards the anti-MRSA and anti-biofilm activities observed. Overall, the study bolsters the potential of strain MUSC 125 as a promising source of anti-MRSA and antibiofilm compounds and warrants further investigation.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  5. Lay MM, Karsani SA, Malek SN
    Int J Mol Sci, 2014 Jan 02;15(1):468-83.
    PMID: 24451128 DOI: 10.3390/ijms15010468
    1-(2,6-Dihydroxy-4-methoxyphenyl)-2-(4-hydroxyphenyl) ethanone (DMHE) was isolated from the ethyl acetate fraction of Phaleria macrocarpa (Scheff.) Boerl fruits and the structure confirmed by GC-MS (gas chromatography-mass spectrometry) and NMR (nuclear magnetic resonance) analysis. This compound was tested on the HT-29 human colon adenocarcinoma cell line using MTT (method of transcriptional and translational) cell proliferation assay. The results of MTT assay showed that DMHE exhibited good cytotoxic effect on HT-29 cells in a dose- and time-dependent manner but no cytotoxic effect on the MRC-5 cell line after 72 h incubation. Morphological features of apoptotic cells upon treatment by DMHE, e.g., cell shrinkage and membrane blebbing, were examined by an inverted and phase microscope. Other features, such as chromatin condension and nuclear fragmentation were studied using acridine orange and propidium iodide staining under the fluorescence microscope. Future evidence of apoptosis/necrosis was provided by result fromannexin V-FITC/PI (fluorescein-isothiocyanate/propidium iodide) staining revealed the percentage of early apoptotic, late apoptotic, necrotic and live cells in a dose- and time-dependent manner using flow cytometry. Cell cycle analysis showed G0/G1 arrest in a time-dependent manner. A western blot analysis indicated that cell death might be associated with the up-regulation of the pro-apoptotic proteins Bax PUMA. However, the anit-apotptic proteins Bcl-2, Bcl-xL, and Mcl-1 were also found to increase in a time-dependent manner. The expression of the pro-apoptotic protein Bak was not observed.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  6. Adam SH, Giribabu N, Kassim N, Kumar KE, Brahmayya M, Arya A, et al.
    Biomed Pharmacother, 2016 Jul;81:439-452.
    PMID: 27261624 DOI: 10.1016/j.biopha.2016.04.032
    INTRODUCTION: Protective effects of Vitis Vinifera seed aqueous extract (VVSAE) against pancreatic dysfunctions and elevation of oxidative stress, inflammation and apoptosis in the pancreas in diabetes were investigated. Histopathological changes in the pancreas were examined under light microscope.

    METHODS: Blood and pancreas were collected from adult male diabetic rats receiving 28days treatment with VVSAE orally. Fasting blood glucose (FBG), glycated hemoglobin (HbA1c), insulin and lipid profile levels and activity levels of anti-oxidative enzymes (superoxide dismutase-SOD, catalase-CAT and glutathione peroxidase-GPx) in the pancreas were determined by biochemical assays. Histopathological changes in the pancreas were examined under light microscopy and levels of insulin, glucose transporter (GLUT)-2, tumor necrosis factor (TNF)-α, Ikkβ and caspase-3 mRNA and protein were analyzed by real-time PCR (qPCR) and immunohistochemistry respectively. Radical scavenging activity of VVSAE was evaluated by in-vitro anti-oxidant assay while gas chromatography-mass spectrometry (GC-MS) was used to identify the major compounds in the extract.

    RESULTS: GC-MS analyses indicated the presence of compounds that might exert anti-oxidative, anti-inflammatory and anti-apoptosis effects. Near normal FBG, HbAIc, lipid profile and serum insulin levels with lesser signs of pancreatic destruction were observed following administration of VVSAE to diabetic rats. Higher insulin, GLUT-2, SOD, CAT and GPx levels but lower TNF-α, Ikkβ and caspase-3 levels were also observed in the pancreas of VVSAE-treated diabetic rats (p<0.05 compared to non-treated diabetic rats). The extract possesses high in-vitro radical scavenging activities.

    CONCLUSION: In conclusions, administration of VVSAE to diabetic rats could help to protect the pancreas against oxidative stress, inflammation and apoptosis-induced damage while preserving pancreatic function near normal in diabetes.

    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  7. Hazalin NA, Lim SM, Cole AL, Majeed AB, Ramasamy K
    Anticancer Drugs, 2013 Sep;24(8):852-61.
    PMID: 23764760 DOI: 10.1097/CAD.0b013e3283635a47
    There is growing interest in the discovery of bioactive metabolites from endophytes as an alternative source of therapeutics. Identification of their therapeutic targets is essential in understanding the underlying mechanisms and enhancing the resultant therapeutic effects. As such, bioactive compounds produced by endophytic fungi from plants at the National Park, Pahang, Malaysia, were investigated. Five known compounds were identified using LC-UV-MS-NMR and they include trichodermol, 7-epi-brefeldin A, (3R,4S)-4-hydroxymellein, desmethyl-lasiodiplodin and cytochalasin D. The present study went on to investigate the potential anticancer effects of these compounds and the corresponding molecular mechanisms of the lead compound against human breast adenocarcinoma, MCF-7. For the preliminary screening, the cytotoxicity and apoptotic effects of these compounds against MCF-7 were examined. The compounds were also tested against noncarcinogenic hepatocytes (WRL68). The differential cytotoxicity was then determined using the MTT assay. Desmethyl-lasiodiplodin was found to suppress the growth of MCF-7, yielding an inhibitory concentration (IC50) that was seven-fold lower than that of the normal cells. The cytotoxic effect of desmethyl-lasiodiplodin was accompanied by apoptosis. Subsequent analysis demonstrated increased expression levels of caspase 3, c-myc and p53. Further, desmethyl-lasiodiplodin resulted in inhibition of monocyte chemotactic protein (MCP)-3, a cytokine involved in cell survival and metastasis. Hence, this study proposed that desmethyl-lasiodiplodin inhibited growth and survival of MCF-7 through the induction of apoptosis. This anticancer effect is mediated, in part, by upregulation of apoptotic genes and downregulation of MCP-3. As desmethyl-lasiodiplodin elicited minimal impact against normal hepatocytes, our findings also imply its potential use as a specific apoptotic agent in breast cancer treatment.
    Matched MeSH terms: Mass Spectrometry
  8. Chen BC, McGown IN, Thong MK, Pitt J, Yunus ZM, Khoo TB, et al.
    J Inherit Metab Dis, 2010 Dec;33 Suppl 3:S159-62.
    PMID: 20177786 DOI: 10.1007/s10545-010-9056-z
    Most cases of adenylosuccinate lyase (ADSL OMIM 103050) deficiency reported to date are confined to the various European ethnic groups. We report on the first Malaysian case of ADSL deficiency, which appears also to be the first reported Asian case. The case was diagnosed among a cohort of 450 patients with clinical features of psychomotor retardation, global developmental delay, seizures, microcephaly and/or autistic behaviour. The patient presented with frequent convulsions and severe myoclonic jerk within the first few days of life and severe psychomotor retardation. The high performance liquid chromatography (HPLC) profile of the urine revealed the characteristic biochemical markers of succinyladenosine (S-Ado) and succinyl-aminoimidazole carboximide riboside (SAICAr). The urinary S-Ado/SAICAr ratio was found to be 1.02 (type I ADSL deficiency). The patient was compound heterozygous for two novel mutations, c.445C > G (p.R149G) and c.774_778insG (p.A260GfsX24).
    Matched MeSH terms: Tandem Mass Spectrometry
  9. Gorain B, Choudhury H, Tekade RK, Karan S, Jaisankar P, Pal TK
    Regul Toxicol Pharmacol, 2016 Dec;82:20-31.
    PMID: 27815174 DOI: 10.1016/j.yrtph.2016.10.020
    Poor aqueous solubility and unfavourable de-esterification of olmesartan medoxomil (a selective angiotensin II receptor blocker), results in low oral bioavailability of less than 26%. Improvement of oral bioavailability with prolonged pharmacodynamics activity of olmesartan in Wistar rats had been approached by nanoemulsification strategy in our previous article [Colloid Surface B, 115, 2014: 286]. In continuation to that work, we herewith report the biodistribution behaviour and 28-day repeated dose sub-chronic toxicity of olmesartan medoxomil nanoemulsion in Wistar rats following oral administration. The levels of olmesartan in collected biological samples were estimated using our validated LC-MS/MS technique. Our biodistribution study showed significantly higher brain concentrations of olmesartan (0.290 ± 0.089 μg/mL, 0.333 ± 0.071 μg/mL and 0.217 ± 0.062 μg/mL at 0.5, 2.0 and 8.0 h post dosing, respectively) when administered orally as nanoemulsion formulation as compared to the aqueous suspension. In addition, the olmesartan nanoemulsion was found to be safe and non-toxic, as it neither produced any lethality nor remarkable haematological, biochemical and structural adverse effects as observed during the 28-days sub-chronic toxicity studies in experimental Wistar rats. It is herewith envisaged that the developed nanoemulsion formulation approach for the delivery of olmesartan medoxomil via oral route can further be explored in memory dysfunction and brain ischemia, for better brain penetration and improved clinical application in stroke patients.
    Matched MeSH terms: Tandem Mass Spectrometry
  10. Teoh PL, Cheng AY, Liau M, Lem FF, Kaling GP, Chua FN, et al.
    Pharm Biol, 2017 Dec;55(1):394-401.
    PMID: 27931178
    CONTEXT: Clinacanthus nutans Lindau (Acanthaceae) is a medicinal plant that has been reported to have anti-inflammatory, antiviral, antimicrobial and antivenom activities. In Malaysia, it has been widely claimed to be effective in various cancer treatments but scientific evidence is lacking.

    OBJECTIVE: This study investigates the chemical constituents, anti-proliferative, and apoptotic properties of C. nutans root extracts.

    MATERIALS AND METHODS: The roots were subjected to solvent extraction using methanol and ethyl acetate. The anti-proliferative effects of root extracts were tested at the concentrations of 10 to 50 μg/mL on MCF-7 and HeLa by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay for 72 h. Morphological changes were observed under light microscope. Pro-apoptotic effects of root extracts were examined using flow cytometric analysis and RT-PCR. The chemical compositions of root extracts were detected using GC-MS.

    RESULTS: The proliferation of MCF-7 cells was inhibited with the IC50 values of 35 and 30 μg/mL, respectively, for methanol and ethyl acetate root extracts. The average inhibition of HeLa cells was ∼25%. Induction of apoptosis in MCF-7 was supported by chromatin condensation, down-regulation of BCL2 and unaltered expression of BAX. However, only ethyl acetate extract caused the loss of mitochondrial membrane potential. GC-MS analysis revealed the roots extracts were rich with terpenoids and phytosterols.

    DISCUSSION AND CONCLUSIONS: The results demonstrated that root extracts promote apoptosis by suppressing BCL2 via mitochondria-dependent or independent manner. The identified compounds might work solely or cooperatively in regulating apoptosis. However, further studies are required to address this.

    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  11. Oskoueian E, Abdullah N, Ahmad S, Saad WZ, Omar AR, Ho YW
    Int J Mol Sci, 2011;12(9):5955-70.
    PMID: 22016638 DOI: 10.3390/ijms12095955
    Defatted Jatropha curcas L. (J. curcas) seed kernels contained a high percentage of crude protein (61.8%) and relatively little acid detergent fiber (4.8%) and neutral detergent fiber (9.7%). Spectrophotometric analysis of the methanolic extract showed the presence of phenolics, flavonoids and saponins with values of 3.9, 0.4 and 19.0 mg/g DM, respectively. High performance liquid chromatography (HPLC) analyses showed the presence of gallic acid and pyrogallol (phenolics), rutin and myricetin (flavonoids) and daidzein (isoflavonoid). The amount of phorbol esters in the methanolic extract estimated by HPLC was 3.0 ± 0.1 mg/g DM. Other metabolites detected by GC-MS include: 2-(hydroxymethyl)-2 nitro-1,3-propanediol, β-sitosterol, 2-furancarboxaldehyde, 5-(hydroxymethy) and acetic acid in the methanolic extract; 2-furancarboxaldehyde, 5-(hydroxymethy), acetic acid and furfural (2-furancarboxaldehyde) in the hot water extract. Methanolic and hot water extracts of kernel meal showed antimicrobial activity against both Gram positive and Gram negative pathogenic bacteria (inhibition range: 0-1.63 cm) at the concentrations of 1 and 1.5 mg/disc. Methanolic extract exhibited antioxidant activities that are higher than hot water extract and comparable to β-carotene. The extracts tended to scavenge the free radicals in the reduction of ferric ion (Fe(3+)) to ferrous ion (Fe(2+)). Cytotoxicity assay results indicated the potential of methanolic extract as a source of anticancer therapeutic agents toward breast cancer cells.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
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