Displaying publications 1 - 20 of 29 in total

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  1. Fulltext Thermotolerance and molecular chaperone function of an SGT1-like protein from the psychrophilic yeast, Glaciozyma antarctica
    Yusof NA, Hashim NH, Beddoe T, Mahadi NM, Illias RM, Bakar FD, et al.
    Cell Stress Chaperones, 2016 Jul;21(4):707-15.
    PMID: 27154490 DOI: 10.1007/s12192-016-0696-2
    The ability of eukaryotes to adapt to an extreme range of temperatures is critically important for survival. Although adaptation to extreme high temperatures is well understood, reflecting the action of molecular chaperones, it is unclear whether these molecules play a role in survival at extremely low temperatures. The recent genome sequencing of the yeast Glaciozyma antarctica, isolated from Antarctic sea ice near Casey Station, provides an opportunity to investigate the role of molecular chaperones in adaptation to cold temperatures. We isolated a G. antarctica homologue of small heat shock protein 20 (HSP20), GaSGT1, and observed that the GaSGT1 mRNA expression in G. antarctica was markedly increased following culture exposure at low temperatures. Additionally, we demonstrated that GaSGT1 overexpression in Escherichia coli protected these bacteria from exposure to both high and low temperatures, which are lethal for growth. The recombinant GaSGT1 retained up to 60 % of its native luciferase activity after exposure to luciferase-denaturing temperatures. These results suggest that GaSGT1 promotes cell thermotolerance and employs molecular chaperone-like activity toward temperature assaults.
    Matched MeSH terms: Enzyme Assays
  2. Fulltext The growth suppressing effects of girinimbine on HepG2 involve induction of apoptosis and cell cycle arrest
    Syam S, Abdul AB, Sukari MA, Mohan S, Abdelwahab SI, Wah TS
    Molecules, 2011 Aug 23;16(8):7155-70.
    PMID: 21862957 DOI: 10.3390/molecules16087155
    Murraya koenigii is an edible herb widely used in folk medicine. Here we report that girinimbine, a carbazole alkaloid isolated from this plant, inhibited the growth and induced apoptosis in human hepatocellular carcinoma, HepG2 cells. The MTT and LDH assay results showed that girinimbine decreased cell viability and increased cytotoxicity in a dose-and time-dependent manner selectively. Girinimbine-treated HepG2 cells showed typical morphological features of apoptosis, as observed from normal inverted microscopy and Hoechst 33342 assay. Furthermore, girinimbine treatment resulted in DNA fragmentation and elevated levels of caspase-3 in HepG2 cells. Girinimbine treatment also displayed a time-dependent accumulation of the Sub-G(0)/G(1) peak (hypodiploid) and caused G(0)/G(1)-phase arrest. Together, these results demonstrated for the first time that girinimbine could effectively induce programmed cell death in HepG2 cells and suggests the importance of conducting further investigations in preclinical human hepatocellular carcinoma models, especially on in vivo efficacy, to promote girinimbine for use as an anticancer agent against hepatocellular carcinoma.
    Matched MeSH terms: Enzyme Assays
  3. The PAL2 promoter activities in relation to structural development and adaptation in Arabidopsis thaliana
    Wong JH, Namasivayam P, Abdullah MP
    Planta, 2012 Feb;235(2):267-77.
    PMID: 21874349 DOI: 10.1007/s00425-011-1506-9
    Phenylalanine ammonia lyase (PAL) plays a major role in plant growth, development and adaptation. In Arabidopsis thaliana, the enzyme is encoded by four genes, namely PAL1, PAL2, PAL3, and PAL4 with PAL1 and PAL2 being closely related phylogenetically and functionally. PAL1 promoter activities are associated with plant development and are inducible by various stress agents. However, PAL2 promoter activities have not been functionally analysed. Here, we show that the PAL2 promoter activities are associated with the structural development of a plant and its organs. This function was inducible in an organ-specific manner by the avirulent strain of Pseudomonas syringae pv. tomato (JL1065). The PAL2 promoter was active throughout the course of the plant development particularly in the root, rosette leaf, and inflorescence stem that provide the plant with structural support. In aerial organs, the levels of PAL2 promoter activities were negatively correlated with relative positions of the organs to the rosette leaves. The promoter was inducible in the root following an inoculation by JL1065 in the leaf suggesting PAL2 to be part of an induced defence system. Our results demonstrate how the PAL2 promoter activities are being coordinated and synchronised for the structural development of the plant and its organs based on the developmental programme. Under certain stress conditions the activity may be induced in favour of certain organs.
    Matched MeSH terms: Enzyme Assays
  4. Synthesis, Antioxidant and In-Silico Studies of Potent Urease Inhibitors: N-(4-{[(4-Methoxyphenethyl)-(substituted)amino]sulfonyl}phenyl)acetamides
    Abbasi MA, Raza H, Rehman AU, Siddiqui SZ, Nazir M, Mumtaz A, et al.
    Drug Res (Stuttg), 2019 Feb;69(2):111-120.
    PMID: 30086567 DOI: 10.1055/a-0654-5074
    In this study, a new series of sulfonamides derivatives was synthesized and their inhibitory effects on DPPH and jack bean urease were evaluated. The in silico studies were also applied to ascertain the interactions of these molecules with active site of the enzyme. Synthesis was initiated by the nucleophilic substitution reaction of 2-(4-methoxyphenyl)-1-ethanamine (1: ) with 4-(acetylamino)benzenesulfonyl chloride (2): in aqueous sodium carbonate at pH 9. Precipitates collected were washed and dried to obtain the parent molecule, N-(4-{[(4-methoxyphenethyl)amino]sulfonyl}phenyl)acetamide (3): . Then, this parent was reacted with different alkyl/aralkyl halides, (4A-M: ), using dimethylformamide (DMF) as solvent and LiH as an activator to produce a series of new N-(4-{[(4-methoxyphenethyl)-(substituted)amino]sulfonyl}phenyl)acetamides (5A-M: ). All the synthesized compounds were characterized by IR, EI-MS, 1H-NMR, 13C-NMR and CHN analysis data. All of the synthesized compounds showed higher urease inhibitory activity than the standard thiourea. The compound 5 F: exhibited very excellent enzyme inhibitory activity with IC50 value of 0.0171±0.0070 µM relative to standard thiourea having IC50 value of 4.7455±0.0546 µM. Molecular docking studies suggested that ligands have good binding energy values and bind within the active region of taget protein. Chemo-informatics properties were evaluated by computational approaches and it was found that synthesized compounds mostly obeyed the Lipinski' rule.
    Matched MeSH terms: Enzyme Assays/methods
  5. Fulltext Ser-653-Asn substitution in the acetohydroxyacid synthase gene confers resistance in weedy rice to imidazolinone herbicides in Malaysia
    Ruzmi R, Ahmad-Hamdani MS, Mazlan N
    PLoS One, 2020;15(9):e0227397.
    PMID: 32925921 DOI: 10.1371/journal.pone.0227397
    The continuous and sole dependence on imidazolinone (IMI) herbicides for weedy rice control has led to the evolution of herbicide resistance in weedy rice populations across various countries growing IMI herbicide-resistant rice (IMI-rice), including Malaysia. A comprehensive study was conducted to elucidate occurrence, level, and mechanisms endowing resistance to IMI herbicides in putative resistant (R) weedy rice populations collected from three local Malaysian IMI-rice fields. Seed bioassay and whole-plant dose-response experiments were conducted using commercial IMI herbicides. Based on the resistance index (RI) quantification in both experiments, the cross-resistance pattern of R and susceptible (S) weedy rice populations and control rice varieties (IMI-rice variety MR220CL2 and non-IMI-rice variety MR219) to imazapic and imazapyr was determined. A molecular investigation was carried out by comparing the acetohydroxyacid synthase (AHAS) gene sequences of the R and S populations and the MR220CL2 and MR219 varieties. The AHAS gene sequences of R weedy rice were identical to those of MR220CL2, exhibiting a Ser-653-Asn substitution, which was absent in MR219 and S plants. In vitro assays were conducted using analytical grade IMI herbicides of imazapic (99.3%) and imazapyr (99.6%) at seven different concentrations. The results demonstrated that the AHAS enzyme extracted from the R populations and MR220CL2 was less sensitive to IMI herbicides than that from S and MR219, further supporting that IMI herbicide resistance was conferred by target-site mutation. In conclusion, IMI resistance in the selected populations of Malaysian weedy rice could be attributed to a Ser-653-Asn mutation that reduced the sensitivity of the target site to IMI herbicides. To our knowledge, this study is the first to show the resistance mechanism in weedy rice from Malaysian rice fields.
    Matched MeSH terms: Enzyme Assays
  6. Fulltext Preliminary screening of plant proteases as a potential source for the development of an inhibitive assay for heavy metals
    Gunasekaran, B., Johari, W.L.W., Wasoh, M.H., Masdor, N.A., Shukor, M.Y.
    Bioremediation Science and Technology Research, 2018;6(1):9-13.
    MyJurnal
    Heavy metals pollution has become a great threat to the world. Since instrumental methods are
    expensive and need skilled technician, a simple and fast method is needed to determine the
    presence of heavy metals in the environment. In this work, a preliminary study was carried out
    on the applicability of various local plants as a source of protease for the future development of
    the inhibitive enzyme assay for heavy-metals. The crude proteases preparation was assayed using
    casein as a substrate in conjunction with the Coomassie dye-binding assay. The crude protease
    from the kesinai plant was found to be the most potent plant protease. The crude enzyme
    exhibited broad temperature and pH ranges for activity and will be developed in the future as a
    potential inhibitive assay for heavy metals.
    Matched MeSH terms: Enzyme Assays
  7. Polyhydroxyalkanoate (PHA) synthase genes and PHA-associated gene clusters in Pseudomonas spp. and Janthinobacterium spp. isolated from Antarctica
    Tan IKP, Foong CP, Tan HT, Lim H, Zain NA, Tan YC, et al.
    J Biotechnol, 2020 Apr 10;313:18-28.
    PMID: 32171790 DOI: 10.1016/j.jbiotec.2020.03.006
    The polyhydroxyalkanoate (PHA) producing capability of four bacterial strains isolated from Antarctica was reported in a previous study. This study analyzed the PHA synthase genes and the PHA-associated gene clusters from the two antarctic Pseudomonas isolates (UMAB-08 and UMAB-40) and the two antarctic Janthinobacterium isolates (UMAB-56 and UMAB-60) through whole-genome sequence analysis. The Pseudomonas isolates were found to carry PHA synthase genes which fall into two different PHA gene clusters, namely Class I and Class II, which are involved in the biosynthesis of short-chain-length-PHA (SCL-PHA) and medium-chain-length-PHA (MCL-PHA), respectively. On the other hand, the Janthinobacterium isolates carry a Class I and an uncharacterized putative PHA synthase genes. No other gene involved in PHA synthesis was detected in close proximity to the uncharacterized putative PHA synthase gene in the Janthinobacterium isolates, therefore it falls into a separate clade from the ordinary Class I, II, III and IV clades of PHA synthase (PhaC) phylogenetic tree. Multiple sequence alignment showed that the uncharacterized putative PHA synthase gene contains all the highly conserved amino acid residues and the proposed catalytic triad of PHA synthase. PHA biosynthesis and in vitro PhaC enzymatic assay results showed that this uncharacterized putative PHA synthase from Janthinobacterium sp. UMAB-60 is funtional. This report adds new knowledge to the PHA synthase database as we describe scarce information of PHA synthase genes and PHA-associated gene clusters from the antarctic bacterial isolates (extreme and geographically isolated environment) and comparing with those from non-antarctic PHA-producing bacteria.
    Matched MeSH terms: Enzyme Assays
  8. Fulltext Pharmacogenomics in drug therapy and interaction: the role of cytochrome P450
    Ong, Chin-Eng, Yan, Pan, Tiong, Kai-Hung, Yiap, Beow-Chin, Tan, Eng-Lai, Pook, Peter, et al.
    International e-Journal of Science, Medicine & Education, 2008;2(3):-.
    MyJurnal
    Pharmacogenomics (or pharmacogenetics), the study of the effects of genetic differences on a person’s response to drugs, can help in optimizing drug efficacy and minimizing adverse drug reactions. Interperson difference in drug metabolism is one of the important consequences of such genetic variation. This variation is determined in part by mutations in cytochrome P450 enzymes (CYPs). IMU is part of a major collaborative research project in the area of phamacogenetics and drug metabolism. Working together with USM and UiTM, our group has, since 2000, generated useful population database on genetic polymorphism of various CYP isoforms. We have successfully genotyped three major ethnic groups, Malay, Indian and Chinese for their allelic frequency of important isoforms. These include CYP2D6, CYP2C9, CYP2C8 and CYP2A6. Data generated so far collectively have contributed to our effort in mapping and constructing genomic database for Malaysian population.
    Since early 2002, our research has been focusing on developing in vitro methods in studying the functional consequences of genetic polymorphism of CYP enzymes. Using site-directed mutagenesis, CYP mutants, carrying nucleotide changes as reported in known alleles in human populations, were generated and expressed in E. coli system, and the expressed recombinant proteins were characterized using enzyme assays to determine the functional consequences of mutations. We have established a series of HPLC (high performance liquid chromatography)-based and fluorescence-based assays to investigate CYP activities. Assays that have been developed include tolbutamide methylhydroxylase, paclitaxel 6α-hydroxylase, dextromethorphan O-demethylation, testosterone 6β-hydroxylation and coumarin 7-hydroxylase assays. These assays serve as activity markers allowing comparison of catalytic activities of mutant proteins generated. Another focus of our work is to use the developed assays as a screening tool to investigate drug-herb interactions. This was achieved by co-incubation of herbal extracts and active constituents with the probe substrates in the assays followed by characterization of the kinetic behaviors of the enzymes involved using various pharmacokinetic parameters such as Km, Vmax, IC50 and Ki. This work is currently carried out with collaboration from the Institute for Medical Research (IMR) and is supported by MOSTI’s eScienceFund under RM9. It is envisaged that this screening work will give us insights on the potential of the commonly used herbs to cause pharmacokinetic interactions with other drug substrates, and allow us to elucidate the mechanisms involved in the interactions.
    Matched MeSH terms: Enzyme Assays
  9. Oxindole based oxadiazole hybrid analogs: Novel α-glucosidase inhibitors
    Taha M, Imran S, Rahim F, Wadood A, Khan KM
    Bioorg Chem, 2018 02;76:273-280.
    PMID: 29223804 DOI: 10.1016/j.bioorg.2017.12.001
    Inhibition of α-glucosidase is an effective strategy for controlling post-prandial hyperglycemia in diabetic patients. Beside these α-glucosidase inhibitors has been also used as anti-obesity and anti-viral drugs. Keeping in view the greater importance of α-glucosidase inhibitors here in this study we are presenting oxindole based oxadiazoles hybrid analogs (1-20) synthesis, characterized by different spectroscopic techniques including 1H NMR and EI-MS and their α-glucosidase inhibitory activity. All compounds were found potent inhibitors for the enzyme with IC50 values ranging between 1.25 ± 0.05 and 268.36 ± 4.22 µM when compared with the standard drug acarbose having IC50 value 895.09 ± 2.04 µM. Our study identifies novel series of potent α-glucosidase inhibitors and further investigation on this may led to the lead compounds. A structure activity relationship has been established for all compounds. The interactions of the active compounds and enzyme active site were established with the help of molecular docking studies.
    Matched MeSH terms: Enzyme Assays
  10. Fulltext Optimization of an Extraction Solvent for Angiotensin-Converting Enzyme Inhibitors from Hibiscus sabdariffa L. Based on Its UPLC-MS/MS Metabolic Profiling
    Salem MA, Michel HE, Ezzat MI, Okba MM, El-Desoky AM, Mohamed SO, et al.
    Molecules, 2020 May 14;25(10).
    PMID: 32422967 DOI: 10.3390/molecules25102307
    Hibiscus species (Malvaceae) have been long used as an antihypertensive folk remedy. The aim of our study was to specify the optimum solvent for extraction of the angiotensin-converting enzyme inhibiting (ACEI) constituents from Hibiscus sabdariffa L. The 80% methanol extract (H2) showed the highest ACEI activity, which exceeds that of the standard captopril (IC50 0.01255 ± 0.00343 and 0.210 ± 0.005 µg/mL, respectively). Additionally, in a comprehensive metabolomics approach, an ultra-performance liquid chromatography (UPLC) coupled to the high resolution tandem mass spectrometry (HRMS) method was used to trace the metabolites from each extraction method. Interestingly, our comprehensive analysis showed that the 80% methanol extract was predominated with secondary metabolites from all classes including flavonoids, anthocyanins, phenolic and organic acids. Among the detected metabolites, phenolic acids such as ferulic and chlorogenic acids, organic acids such as citrate derivatives and flavonoids such as kaempferol have been positively correlated to the antihypertensive potential. These results indicates that these compounds may significantly contribute synergistically to the ACE inhibitory activity of the 80% methanol extract.
    Matched MeSH terms: Enzyme Assays
  11. On optimizing the blocking step of indirect enzyme-linked immunosorbent assay for Epstein-Barr virus serology
    Lim CS, Krishnan G, Sam CK, Ng CC
    Clin Chim Acta, 2013 Jan 16;415:158-61.
    PMID: 23043757 DOI: 10.1016/j.cca.2012.08.031
    Because blocking agent occupies most binding surface of a solid phase, its ability to prevent nonspecific binding determines the signal-to-noise ratio (SNR) and reliability of an enzyme-linked immunosorbent assay (ELISA).
    Matched MeSH terms: Enzyme Assays/standards*
  12. Fulltext New cholinesterase inhibitory constituents from Lonicera quinquelocularis
    Khan D, Khan HU, Khan F, Khan S, Badshah S, Khan AS, et al.
    PLoS One, 2014;9(4):e94952.
    PMID: 24733024 DOI: 10.1371/journal.pone.0094952
    A phytochemical investigation on the ethyl acetate soluble fraction of Lonicera quinquelocularis (whole plant) led to the first time isolation of one new phthalate; bis(7-acetoxy-2-ethyl-5-methylheptyl) phthalate (3) and two new benzoates; neopentyl-4-ethoxy-3, 5-bis (3-methyl-2-butenyl benzoate (4) and neopentyl-4-hydroxy-3, 5-bis (3-methyl-2-butenyl benzoate (5) along with two known compounds bis (2-ethylhexyl phthalate (1) and dioctyl phthalate (2). Their structures were established on the basis of spectroscopic analysis and by comparison with available data in the literature. All the compounds (1-5) were tested for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities in dose dependent manner. The IC50 (50% inhibitory effect) values of compounds 3 and 5 against AChE were 1.65 and 3.43 µM while the values obtained against BChE were 5.98 and 9.84 µM respectively. Compounds 2 and 4 showed weak inhibition profile.
    Matched MeSH terms: Enzyme Assays
  13. Modified DNase tube test to detect DNase activity in Stenotrophomonas maltophilia
    Neela V, Thomas R, Rankouhi SZR, Karunanidhi A, Shueh CS, Hamat RA, et al.
    J Med Microbiol, 2012 Dec;61(Pt 12):1792-1794.
    PMID: 22956752 DOI: 10.1099/jmm.0.049403-0
    Matched MeSH terms: Enzyme Assays*
  14. Lignin biodegradation and ligninolytic enzyme studies during biopulping of Acacia mangium wood chips by tropical white rot fungi
    Liew CY, Husaini A, Hussain H, Muid S, Liew KC, Roslan HA
    World J Microbiol Biotechnol, 2011 Jun;27(6):1457-68.
    PMID: 25187145 DOI: 10.1007/s11274-010-0598-x
    White rot fungi are good lignin degraders and have the potential to be used in industry. In the present work, Phellinus sp., Daedalea sp., Trametes versicolor and Pycnoporus coccineus were selected due to their relatively high ligninolytic enzyme activity, and grown on Acacia mangium wood chips under solid state fermentation. Results obtained showed that manganese peroxidase produced is far more compared to lignin peroxidase, suggesting that MnP might be the predominating enzymes causing lignin degradation in Acacia mangium wood chips. Cellulase enzyme assays showed that no significant cellulase activity was detected in the enzyme preparation of T. versicolor and Phellinus sp. This low cellulolytic activity further suggests that these two white rot strains are of more interest in lignin degradation. The results on lignin losses showed 20-30% of lignin breakdown at 60 days of biodegradation. The highest lignin loss was found in Acacia mangium biotreated with T. versicolor after 60 days and recorded 26.9%, corresponding to the percentage of their wood weight loss recorded followed by P. coccineus. In general, lignin degradation was only significant from 20 days onwards. The overall percentage of lignin weight loss was within the range of 1.02-26.90% over the biodegradation periods. Microscopic observations conducted using scanning electron microscope showed that T. versicolor, P. coccineus, Daedalea sp. and Phellinus sp. had caused lignin degradation in Acacia mangium wood chips.
    Matched MeSH terms: Enzyme Assays
  15. Fulltext In vitro and in silico studies of chalcone synthase variant 2 in Boesenbergia rotunda and its substrate specificity
    Sanmugavelan R, Teoh TC, Roslan N, Mohamed Z
    Turk J Biol, 2018;42(3):213-223.
    PMID: 30814883 DOI: 10.3906/biy-1710-107
    In this study, transformation of BrCHS var 2 into B. rotunda cell suspension culture, followed by chalcone synthase enzymatic assay and HPLC analysis was conducted to investigate whether the substrate specificity for BrCHS var 2 is either cinnamoyl-CoA or p-coumaroyl-CoA. The HPLC profile showed an increase in the amount of pinocembrin chalcone when cinnamoyl-CoA and malonyl-CoA were added but not p-coumaroyl-CoA. Molecular docking was performed to explore the binding of cinnamoyl-CoA and p-coumaroyl-CoA to BrCHS var 2 receptor and the docking results showed that cinnamoyl-CoA formed numerous hydrogen bonds and more negative docked energy than p-coumaroyl-CoA. Cinnamoyl-CoA showed good interactions with Cys 164 to initiate the subsequent formation of pinocembrin chalcone, whereas the hydroxyl group of p-coumaroyl-CoA formed an unfavorable interaction with Gln 161 that caused steric hindrance to subsequent formation of naringenin chalcone. Docked conformation analysis results also showed that malonyl-CoA formed hydrogen bonding with Cys 164, His 303, and Asn 336 residues in BrCHS var 2. The results show that cinnamoyl-CoA is the preferred substrate for BrCHS var 2.
    Matched MeSH terms: Enzyme Assays
  16. Fulltext Evaluation of the effects of Mitragyna speciosa alkaloid extract on cytochrome P450 enzymes using a high throughput assay
    Kong WM, Chik Z, Ramachandra M, Subramaniam U, Aziddin RE, Mohamed Z
    Molecules, 2011 Aug 29;16(9):7344-56.
    PMID: 21876481 DOI: 10.3390/molecules16097344
    The extract from Mitragyna speciosa has been widely used as an opium substitute, mainly due to its morphine-like pharmacological effects. This study investigated the effects of M. speciosa alkaloid extract (MSE) on human recombinant cytochrome P450 (CYP) enzyme activities using a modified Crespi method. As compared with the liquid chromatography-mass spectrometry method, this method has shown to be a fast and cost-effective way to perform CYP inhibition studies. The results indicated that MSE has the most potent inhibitory effect on CYP3A4 and CYP2D6, with apparent half-maximal inhibitory concentration (IC(50)) values of 0.78 µg/mL and 0.636 µg/mL, respectively. In addition, moderate inhibition was observed for CYP1A2, with an IC(50) of 39 µg/mL, and weak inhibition was detected for CYP2C19. The IC(50) of CYP2C19 could not be determined, however, because inhibition was <50%. Competitive inhibition was found for the MSE-treated CYP2D6 inhibition assay, whereas non-competitive inhibition was shown in inhibition assays using CYP3A4, CYP1A2 and CYP2C19. Quinidine (CYP2D6), ketoconazole (CYP3A4), tranylcypromine (CYP2C19) and furafylline (CYP1A2) were ACCESSused as positive controls throughout the experiments. This study shows that MSE may contribute to an herb-drug interaction if administered concomitantly with drugs that are substrates for CYP3A4, CYP2D6 and CYP1A2.
    Matched MeSH terms: Enzyme Assays
  17. Evaluation of Herb-Drug Interaction of Synacinn™ and Individual Biomarker through Cytochrome 450 Inhibition Assay
    Ab Rahman NS, Abd Majid FA, Abd Wahid ME, Zainudin AN, Zainol SN, Ismail HF, et al.
    Drug Metab Lett, 2018;12(1):62-67.
    PMID: 29542427 DOI: 10.2174/1872312812666180314112457
    BACKGROUND: SynacinnTM contains five standardized herbal extracts of Orthosiphon Stamineus (OS), Syzygium polyanthum (SZ), Curcuma xantorrizza (CX), Cinnamomum zeylanicum (CZ) and Andrographis paniculata (AP) and is standardized against phytochemical markers of rosmarinic acid, gallic acid, curcumin, catechin and andrographolide respectively. This herbal medicine has been used as health supplement for diabetes. SynacinnTM is recommended to be consumed as supplement to the diabetic drugs. However, herb-drug interaction of SynacinnTM polyherbal with present drugs is unknown.

    METHODS: This study was designed to investigate the effect of SynacinnTM and its individual biomarkers on drug metabolizing enzymes (CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP3A4 (Midazolam), CYP3A4 (Testosteron)), to assess its herb-drug interaction potential through cytochrome P450 inhibition assay. This study was conducted using liquid chromatography- tandem mass spectroscopy (LC-MS/MS) using probe substrates using human liver microsomes against CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP3A4 (Midazolam) and CYP3A4 (Testosteron).

    RESULTS: Result showed that SynacinnTM at maximum concentration (5000 µg/ml) 100% inhibit CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP3A4 (Midazolam) and CYP3A4 (Testosteron). IC50 values determined were 0.23, 0.60, 0.47, 0.78, 1.23, 0.99, 1.01, and 0.91 mg/ml for CYP 1A2, 2B6, 2C8, 2C9, 2C19, 2D6, 3A4 (midazolam) and 3A4 (testosterone), respectively. Meanwhile, all individual biomarkers showed no, less or moderate inhibitory effect towards all the tested CYP450 except for curcumin that showed inhibition of CYP2C8 (91%), CYP2C9 (81%) and CYP2C19 (72%) at 10µM.

    CONCLUSION: Curcumin was found to be an active constituent that might contribute to the inhibition of SynacinnTM against CYP2C8, CYP2C9 and CYP2C19. It can be suggested that SynacinnTM can be consumed separately from a drug known to be metabolized by all tested CYP450 enzymes.

    Matched MeSH terms: Enzyme Assays
  18. Development of an inhibitive enzyme assay for copper
    Shukor MY, Bakar NA, Othman AR, Yunus I, Shamaan NA, Syed MA
    J Environ Biol, 2009 Jan;30(1):39-44.
    PMID: 20112861
    In this work the development of an inhibitive assay for copper using the molybdenum-reducing enzyme assay is presented. The enzyme is assayed using 12-molybdophosphoric acid at pH 5.0 as an electron acceptor substrate and NADH as the electron donor substrate. The enzyme converts the yellowish solution into a deep blue solution. The assay is based on the ability of copper to inhibit the molybdenum-reducing enzyme from the molybdate-reducing Serratia sp. Strain DRY5. Other heavy metals tested did not inhibit the enzyme at 10 mg l(-1). The best model with high regression coefficient to measure copper inhibition is one-phase binding. The calculated IC50 (concentration causing 50% inhibition) is 0.099 mg l(-1) and the regression coefficient is 0.98. The comparative LC50, EC50 and IC50 data for copper in different toxicity tests show that the IC50 value for copper in this study is lower than those for immobilized urease, bromelain, Rainbow trout, R. meliloti, Baker's Yeast dehydrogenase activity Spirillum volutans, P. fluorescens, Aeromonas hydrophilia and synthetic activated sludge assays. However the IC50 value is higher than those for Ulva pertusa and papain assays, but within the reported range for Daphnia magna and Microtox assays.
    Matched MeSH terms: Enzyme Assays/methods*
  19. Fulltext Development of MTH1-Binding Nucleotide Analogs Based on 7,8-Dihalogenated 7-Deaza-dG Derivatives
    Shi H, Ishikawa R, Heh CH, Sasaki S, Taniguchi Y
    Int J Mol Sci, 2021 Jan 28;22(3).
    PMID: 33525366 DOI: 10.3390/ijms22031274
    MTH1 is an enzyme that hydrolyzes 8-oxo-dGTP, which is an oxidatively damaged nucleobase, into 8-oxo-dGMP in nucleotide pools to prevent its mis-incorporation into genomic DNA. Selective and potent MTH1-binding molecules have potential as biological tools and drug candidates. We recently developed 8-halogenated 7-deaza-dGTP as an 8-oxo-dGTP mimic and found that it was not hydrolyzed, but inhibited enzyme activity. To further increase MTH1 binding, we herein designed and synthesized 7,8-dihalogenated 7-deaza-dG derivatives. We successfully synthesized multiple derivatives, including substituted nucleosides and nucleotides, using 7-deaza-dG as a starting material. Evaluations of the inhibition of MTH1 activity revealed the strong inhibitory effects on enzyme activity of the 7,8-dihalogenated 7-deaza-dG derivatives, particularly 7,8-dibromo 7-daza-dGTP. Based on the results obtained on kinetic parameters and from computational docking simulating studies, these nucleotide analogs interacted with the active site of MTH1 and competitively inhibited the substrate 8-oxodGTP. Therefore, novel properties of repair enzymes in cells may be elucidated using new compounds.
    Matched MeSH terms: Enzyme Assays
  20. Detection of toluene degradation in bacteria isolated from oil contaminated soils
    Ainon Hamzah, Tavakoli A, Amir Rabu
    Sains Malaysiana, 2011;40:1231-1235.
    Toluene (C7H8) a hydrocarbon in crude oil, is a common contaminant in soil and groundwater. In this study, the ability to degrade toluene was investigated from twelve bacteria isolates which were isolated from soil contaminated with oil. Out of 12 bacterial isolates tested, most of Pseudomonas sp. showed the capability to grow in 1 mM of toluene compared with other isolates on the third day of incubation. Based on enzyme assays towards toluene monooxygenase, Pseudomonas aeruginosa UKMP-14T and Bacillus cereus UKMP-6G were shown to have the highest ability to degrade toluene. The toluene monoxygenase activity was analysed by using two calorimetric methods, Horseradish peroxidase (HRP) and indole-indigo. Both of the methods measured the production of catechol by the enzymatic reaction of toluene monooxygenase. In the HRP assay, the highest enzyme activity was 0.274 U/mL, exhibited by Pseudomonas aeruginosa UKMP-14T. However, for indole-indigo assay, Bacillus cereus UKMP-6G produced the highest enzyme activity of 0.291 U/ml. Results from both experiments showed that Pseudomonas aeruginosa UKMP-14T and Bacillus cereus UKMP-6G were able to degrade toluene.
    Matched MeSH terms: Enzyme Assays
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