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  1. Sequential synthesis of amino-1,4-naphthoquinone-appended triazoles and triazole-chromene hybrids and their antimycobacterial evaluation
    Devi Bala B, Muthusaravanan S, Choon TS, Ashraf Ali M, Perumal S
    Eur J Med Chem, 2014 Oct 6;85:737-46.
    PMID: 25129868 DOI: 10.1016/j.ejmech.2014.08.009
    A general method for the synthesis of a library of hitherto unreported amino-1,4-naphthoquinone-appended triazoles was accomplished via a sequential three-component reaction of substituted N-propargylaminonaphthoquinones with variously substituted alkyl bromides/2-bromonaphthalene-1,4-dione and sodium azide in the presence of Et3N/CuI in water. Aminonaphthoquinone-appended iminochromene-triazole hybrid heterocycles were also synthesized from the amino-1,4-naphthoquinone-appended-1,2,3-triazolylacetonitriles. All the triazole hybrids were screened for their in vitro activity against Mycobacterium tuberculosis H37Rv (MTB). Among the triazoles, 2-(((1-benzyl-1H-1,2,3-triazol-4-yl)methyl)(4-(trifluoromethyl)phenyl)amino)naphthalene-1,4-dione (7d) emerged as the most active one with IC50 = 1.87 μM, being more potent than the anti-TB drugs, cycloserine (6 times), pyrimethamine (20 times) and equipotent as the drug ethambutol (IC50 
    Matched MeSH terms: Naphthoquinones/chemical synthesis*; Naphthoquinones/pharmacology*; Naphthoquinones/chemistry
  2. In vitro and in vivo evaluation of self-microemulsifying drug delivery system of buparvaquone
    Venkatesh G, Majid MI, Mansor SM, Nair NK, Croft SL, Navaratnam V
    Drug Dev Ind Pharm, 2010 Jun;36(6):735-45.
    PMID: 20136493 DOI: 10.3109/03639040903460446
    The aim of this study was to prepare a lipid-based self-microemulsifying drug delivery system (SMEDDS) to increase the solubility and oral bioavailability of a poorly water-soluble compound, buparvaquone (BPQ).
    Matched MeSH terms: Naphthoquinones/administration & dosage; Naphthoquinones/blood; Naphthoquinones/chemistry*
  3. Differential proteomic analysis on the effects of 2-methoxy-1,4-naphthoquinone towards MDA-MB-231 cell line
    Liew K, Yong PV, Navaratnam V, Lim YM, Ho AS
    Phytomedicine, 2015 May 15;22(5):517-27.
    PMID: 25981917 DOI: 10.1016/j.phymed.2015.03.007
    We have previously reported the anti-metastatic effects of 2-methoxy-1,4-naphthoquinone (MNQ) against MDA-MB-231 cell line.
    Matched MeSH terms: Naphthoquinones/pharmacology*
  4. Optimization and validation of RP-HPLC-UV method with solid-phase extraction for determination of buparvaquone in human and rabbit plasma: application to pharmacokinetic study
    Venkatesh G, Majid MI, Ramanathan S, Mansor SM, Nair NK, Croft SL, et al.
    Biomed Chromatogr, 2008 May;22(5):535-41.
    PMID: 18205140 DOI: 10.1002/bmc.965
    A simple, sensitive and specific reversed-phase high-performance liquid chromatographic method with UV detection at 251 nm was developed for quantitation of buparvaquone (BPQ) in human and rabbit plasma. The method utilizes 250 microL of plasma and sample preparation involves protein precipitation followed by solid-phase extraction. The method was validated on a C18 column with mobile phase consisting of ammonium acetate buffer (0.02 m, pH 3.0) and acetonitrile in the ratio of 18:82 (v/v) at a flow rate of 1.1 mL/min. The calibration curves were linear (correlation coefficient>or=0.998) in the selected range. The method is specific and sensitive with limit of quantitation of 50 ng/mL for BPQ. The validated method was found to be accurate and precise in the working calibration range. Stability studies were carried out at different storage conditions and BPQ was found to be stable. Partial validation studies were carried out using rabbit plasma and intra- and inter-day precision and accuracy were within 7%. This method is simple, reliable and can be routinely used for preclinical pharmacokinetic studies for BPQ.
    Matched MeSH terms: Naphthoquinones/blood*; Naphthoquinones/pharmacokinetics*; Naphthoquinones/chemistry
  5. Molecular docking, synthesis, and biological evaluation of naphthoquinone as potential novel scaffold for H5N1 neuraminidase inhibition
    Sharma G, Vasanth Kumar S, Wahab HA
    J Biomol Struct Dyn, 2018 01;36(1):233-242.
    PMID: 28013578 DOI: 10.1080/07391102.2016.1274271
    A series of dimeric naphthoquinones containing natural 2-hydroxy-1-4-naphthoquinone moiety was designed, synthesized, and evaluated against neuraminidase of H5N1 virus. p-hydroxy derivatives showed higher inhibition when compared to p-halogenated compounds. Molecular docking studies conducted with H5N1 neuraminidase clearly demonstrated different binding modes of the most active compound onto the open and closed conformations of loop 150. The results thus provide not only evidences of a novel scaffold evaluated as inhibitor, but also a rational explanation involving molecular modeling and the role of loop 150 in the binding.
    Matched MeSH terms: Naphthoquinones/metabolism; Naphthoquinones/pharmacology; Naphthoquinones/chemistry*
  6. Activity of extracts and naphthoquinones from Kigelia pinnata against Trypanosoma brucei brucei and Trypanosoma brucei rhodesiense
    Moideen SV, Houghton PJ, Rock P, Croft SL, Aboagye-Nyame F
    Planta Med, 1999 Aug;65(6):536-40.
    PMID: 10483374
    Dichloromethane extracts of the root bark and stem bark of Kigelia pinnata collected from Zimbabwe exhibited antitrypanosomal activity against Trypanosoma brucei brucei in vitro. Activity-guided fractionation led to the isolation of four naphthoquinones from both the root and stem bark of the plant. The compounds were identified as 2-(1-hydroxyethyl)-naphtho[2,3-b]furan-4,9-quinone (1), isopinnatal (2), kigelinol (3), and isokigelinol (4). Subsequently, the compounds were assessed for antitrypanosomal activity against T. brucei brucei and T. brucei rhodesiense bloodstream form trypomastigotes in vitro. Compound 1 with a furanonaphthoquinone structure was found to possess pronounced activity against both parasites with IC50 values of 0.12 and 0.045 microM, respectively, although it was less active than the standard drug pentamidine. Compounds 2, 3, and 4 also exhibited activity against the parasites, although to a lesser extent. The activities of the compounds were further assessed by comparison with the cytotoxic activities obtained against KB cell lines.
    Matched MeSH terms: Naphthoquinones/isolation & purification; Naphthoquinones/pharmacology*; Naphthoquinones/chemistry
  7. Fulltext A systematic review of the efficacy of a single dose artemisinin-naphthoquine in treating uncomplicated malaria
    Naing C, Whittaker MA, Mak JW, Aung K
    Malar J, 2015;14:392.
    PMID: 26445424 DOI: 10.1186/s12936-015-0919-5
    This study aimed to synthesize the existing evidence on the efficacy and safety of a single dose artemisinin-naphthoquine (ASNQ) for treatment of uncomplicated malaria in endemic countries.
    Matched MeSH terms: Naphthoquinones/administration & dosage*; Naphthoquinones/adverse effects
  8. 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: Naphthoquinones/isolation & purification*; Naphthoquinones/pharmacology
  9. 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: Naphthoquinones/isolation & purification*; Naphthoquinones/pharmacology
  10. Two new naphthoquinone derivatives from the stem bark of Callicarpa maingayi
    Asiri SM, Shaari K, Abas F, Al-Mekhlafi NA, Lajis NH
    Nat Prod Commun, 2012 Oct;7(10):1333-6.
    PMID: 23157003
    Two new naphthoquinones designated as 3alpha-hydroxy-2-(2-hydroxypropan-2-yI)-9alpha-methoxy-2,3,3alpha,9alpha-tetra-hydronaphtho[2,3-b]furan-4,9-dione (callicarpa-quinone A, 1) and 5-hydroxy-2-(2-hydroxypropan-2-yl)naphtho[2,3-b]furan-4,9-dione (callicarpaquinone B, 2) were isolated from the chloroform fraction of Callicarpa maingayi. Three other known compounds, identified as avicequinone-C (3), wodeshiol (4) and paulownin (5), were reported for the first time from this species. The structure elucidation of compounds was established by comprehensive 1D and 2D NMR spectroscopic analyses as well as EIMS, UV and IR spectral data. Compounds 1 and 2 were tested in vitro for their cytotoxic activity against human breast cancer MCF-7cells. Compound 2 exhibited strong cytotoxic activity with an IC50 value of 1.9 +/- 0.2 microM, while 1 showed moderate activity with an IC50 value of 25.0 +/- 4.3 microM.
    Matched MeSH terms: Naphthoquinones/isolation & purification; Naphthoquinones/pharmacology; Naphthoquinones/chemistry*
  11. Synthesis and characterization of lawsone-lntercalated Zn-Al-layered double hydroxides
    Yasin Y, Ismail NM, Hussein MZ, Aminudin N
    J Biomed Nanotechnol, 2011 Jun;7(3):486-8.
    PMID: 21830495
    A drug-inorganic nanostructured material involving pharmaceutically active compound lawsone intercalated Zn-Al layered double hydroxides (Law-LDHs) with Zn/AI = 4 has been assembled by co-precipitation and ion exchange methods. Powder X-ray diffraction (XRD) and Fourier transform infrared spectra (FTIR) analysis indicate a successful intercalation of lawsone between the layers of layered double hydroxides. It suggests that layered double hydroxides may have application as the basis of a drug delivery system.
    Matched MeSH terms: Naphthoquinones/chemistry*
  12. Fulltext 2-Methoxy-1,4-Naphthoquinone (MNQ) Inhibits Glucose Uptake and Lactate Production in Triple-Negative Breast Cancer Cells
    Daud SM, Yaacob NS, Fauzi AN
    Asian Pac J Cancer Prev, 2021 Feb 01;22(S1):59-65.
    PMID: 33576213 DOI: 10.31557/APJCP.2021.22.S1.59
    OBJECTIVE: The persistent activation of aerobic glycolysis in cancer cells results in accumulation of lactate and other metabolic intermediates that contribute to tumorigenesis. Increased glycolysis is frequently dysregulated in triple-negative breast cancer (TNBC), which promotes tumor growth and immune escape. This study was conducted to investigate the effect of 2-methoxy-1, 4-naphthoquinone (MNQ), compound extracted from Impatiens balsamina on glycolytic activities in human breast adenocarcinoma, MDA-MB-231 cells.

    METHODS: Initially, MTT proliferation assay was used to test the cell viability with various doses of MNQ (5-100 µM). As the half maximal inhibitory concentration (IC50) was obtained, glucose uptake and lactate assays of the cells were tested with IC50 dose of MNQ. The treated cells were also subjected to gene and protein analysis of glycolysis-related molecules (GLUT1 and Akt).

    RESULTS: The results showed that MNQ decreased the percentage of MDA-MB-231 cell viability in a dose-dependent manner with the IC50 value of 29 µM. The percentage of glucose uptake into the cells and lactate production decreased significantly after treatment with MNQ as compared to untreated cells. Remarkably, the expressions of GLUT1 and Akt molecules decreased in MNQ-treated cells, suggesting that the inhibition of glycolysis by MNQ is GLUT1-dependent and possibly mediated by the Akt signaling pathway.

    CONCLUSION: Our findings indicate the ability of MNQ to inhibit the glycolytic activities as well as glycolysis-related molecules in MDA-MB-231 cells, suggesting the potential of MNQ to be further developed as an effective anticancer agent against TNBC cells.

    Matched MeSH terms: Naphthoquinones/pharmacology*
  13. 2-Methoxy-1,4-Naphthoquinone (MNQ) suppresses the invasion and migration of a human metastatic breast cancer cell line (MDA-MB-231)
    Liew K, Yong PV, Lim YM, Navaratnam V, Ho AS
    Toxicol In Vitro, 2014 Apr;28(3):335-9.
    PMID: 24291160 DOI: 10.1016/j.tiv.2013.11.008
    Metastasis contributes to the escalating mortality rate among cancer patients worldwide. The search for novel and more effective anti-metastatic agent is crucial owing to the lack of anticancer drugs that can successfully combat metastasis. Hence, this study aims to examine the effects of 2-Methoxy-1,4-Naphthoquinone (MNQ) towards the metastasis of MDA-MB-231 cells. In invasion assays, the number of cells permeating across a Matrigel barrier was found to be decreased in a dose-dependent manner upon treatment with MNQ (0-7.5 μM). In wound-healing migration assays, MNQ exhibited dose-dependent inhibition of cell migration in which significant reduction in the zone of closure was observed as compared to untreated controls. Furthermore, the proteolytic activity of a pivotal metastatic mediator, matrix metalloproteinase-9 (MMP-9) was also downregulated by MNQ as determined by gelatin zymography. This study reports for the first time, the ability of MNQ to inhibit the invasion and migration characteristics of a highly metastatic MDA-MB-231 cancer cell line.
    Matched MeSH terms: Naphthoquinones/administration & dosage; Naphthoquinones/pharmacology*
  14. Development and validation of RP-HPLC-UV method for simultaneous determination of buparvaquone, atenolol, propranolol, quinidine and verapamil: a tool for the standardization of rat in situ intestinal permeability studies
    Venkatesh G, Ramanathan S, Mansor SM, Nair NK, Sattar MA, Croft SL, et al.
    J Pharm Biomed Anal, 2007 Mar 12;43(4):1546-51.
    PMID: 17157469
    A simple, sensitive and specific reversed phase high performance liquid chromatographic (RP-HPLC) method with UV detection at 251 nm was developed for simultaneous quantitation of buparvaquone (BPQ), atenolol, propranolol, quinidine and verapamil. The method was applicable in rat in situ intestinal permeability study to assess intestinal permeability of BPQ, a promising lead compound for Leishmania donovani infections. The method was validated on a C-4 column with mobile phase comprising ammonium acetate buffer (0.02 M, pH 3.5) and acetonitrile in the ratio of 30:70 (v/v) at a flow rate of 1.0 ml/min. The retention times for atenolol, quinidine, propranolol, verapamil and BPQ were 4.30, 5.96, 6.55, 7.98 and 8.54 min, respectively. The calibration curves were linear (correlation coefficient > or =0.996) in the selected range of each analyte. The method is specific and sensitive with limit of quantitation of 15 microg/ml for atenolol, 0.8 microg/ml for quinidine, 5 microg/ml for propranolol, 10 microg/ml for verapamil and 200 ng/ml for BPQ. The validated method was found to be accurate and precise in the working calibration range. Stability studies were carried out at different storage conditions and all the analytes were found to be stable. This method is simple, reliable and can be routinely used for accurate permeability characterization.
    Matched MeSH terms: Naphthoquinones/analysis*; Naphthoquinones/pharmacokinetics; Naphthoquinones/chemistry
  15. Natural dye-sensitized solar cell based on nanocrystalline TiO2
    Khalil Ebrahim Jasim
    Sains Malaysiana, 2012;41:1011-1016.
    During the last quarter of the twentieth century there have been intensive research activities looking for green sources of energy. The main aim of the green generators or converters of energy is to replace the conventional (fossil) energy sources, hence reducing further accumulation of the green house gasses GHGs. Conventional silicon and III-V semiconductor solar cell based on crystalline bulk, quantum well and quantum dots structure or amorphous and thin film structures provided a feasible solution. However, natural dye sensitized solar cells NDSSC are a promising class of photovoltaic cells with the capability of generating green energy at low production cost since no vacuum systems or expensive equipment are required in their fabrication. Also, natural dyes are abundant, easily extracted and safe materials. In NDSSC, once dye molecules exposed to light they become oxidized and transfer electrons to a nanostructured layer of wide bandgap semiconductors such as TiO2. The generated electrons are drawn outside the cell through ohmic contact to a load. In this paper we review the structure and operation principles of the dye sensitized solar cell DSSC. We discuss preparation procedures, optical and electrical characterization of the NDSSC using local dyes extracted from Henna (lawsonia inermis L.), pomegranate, cherries and Bahraini raspberries (rubus spp.). These natural organic dyes are potential candidates to replace some of the man-made dyes used as sensitizer in many commercialized photoelectrochemical cells. Factors limiting the operation of the DSSC are discussed. NDSSCs are expected to be a favored choice in the building-integrated
    photovoltaics (BIPV) due to their robustness, therefore, requiring no special shielding from natural events such as tree strikes or hails.
    Matched MeSH terms: Naphthoquinones
  16. Fulltext Comparative transcriptome analysis to identify candidate genes involved in 2-methoxy-1,4-naphthoquinone (MNQ) biosynthesis in Impatiens balsamina L
    Foong LC, Chai JY, Ho ASH, Yeo BPH, Lim YM, Tam SM
    Sci Rep, 2020 09 30;10(1):16123.
    PMID: 32999341 DOI: 10.1038/s41598-020-72997-2
    Impatiens balsamina L. is a tropical ornamental and traditional medicinal herb rich in natural compounds, especially 2-methoxy-1,4-naphthoquinone (MNQ) which is a bioactive compound with tested anticancer activities. Characterization of key genes involved in the shikimate and 1,4-dihydroxy-2-naphthoate (DHNA) pathways responsible for MNQ biosynthesis and their expression profiles in I. balsamina will facilitate adoption of genetic/metabolic engineering or synthetic biology approaches to further increase production for pre-commercialization. In this study, HPLC analysis showed that MNQ was present in significantly higher quantities in the capsule pericarps throughout three developmental stages (early-, mature- and postbreaker stages) whilst its immediate precursor, 2-hydroxy-1,4-naphthoquinone (lawsone) was mainly detected in mature leaves. Transcriptomes of I. balsamina derived from leaf, flower, and three capsule developmental stages were generated, totalling 59.643 Gb of raw reads that were assembled into 94,659 unigenes (595,828 transcripts). A total of 73.96% of unigenes were functionally annotated against seven public databases and 50,786 differentially expressed genes (DEGs) were identified. Expression profiles of 20 selected genes from four major secondary metabolism pathways were studied and validated using qRT-PCR method. Majority of the DHNA pathway genes were found to be significantly upregulated in early stage capsule compared to flower and leaf, suggesting tissue-specific synthesis of MNQ. Correlation analysis identified 11 candidate unigenes related to three enzymes (NADH-quinone oxidoreductase, UDP-glycosyltransferases and S-adenosylmethionine-dependent O-methyltransferase) important in the final steps of MNQ biosynthesis based on genes expression profiles consistent with MNQ content. This study provides the first molecular insight into the dynamics of MNQ biosynthesis and accumulation across different tissues of I. balsamina and serves as a valuable resource to facilitate further manipulation to increase production of MNQ.
    Matched MeSH terms: Naphthoquinones/metabolism*
  17. Studies on the interaction of mononuclear metal(II) complexes of amino‑naphthoquinone with bio-macromolecules
    Kosiha A, Lo KM, Parthiban C, Elango KP
    Mater Sci Eng C Mater Biol Appl, 2019 Jan 01;94:778-787.
    PMID: 30423764 DOI: 10.1016/j.msec.2018.10.021
    Three metal(II) complexes [CoLCl2], [CuLCl2] and [ZnL2Cl2] {L = 2‑chloro‑3‑((3‑dimethylamino)propylamino)naphthalene‑1,4‑dione} have been synthesized and characterized using analytical, thermal and spectral techniques (FT-IR, UV-Vis, ESR and ESI-MS). The structure of the L has been confirmed by single crystal XRD study. The complexes show good binding propensity to bovine serum albumin (BSA) having relatively higher binding constant values (104 M-1) than the ligand. Fluorescence spectral studies indicate that [CoLCl2] binds relatively stronger with CT DNA through intercalative mode, exhibiting higher binding constant (2.22 × 105 M-1). Agarose gel electrophoresis run on plasmid DNA (pUC18) prove that all the complexes showed efficient DNA cleavage via hydroxyl radical mechanism. The complexes were identified as potent anticancer agents against two human cancer cell lines (MCF7 and A549) by comparing with cisplatin. Co(II) complex demonstrated greater cytotoxicity against MCF7 and A549 cells with IC50 values at 19 and 22 μM, respectively.
    Matched MeSH terms: Naphthoquinones/chemistry*
  18. Synergistic Antibacterial Activity Between 1,4-Naphthoquinone and β-Lactam Antibiotics Against Methicillin-Resistant Staphylococcus aureus
    Yap JKY, Tan SYY, Tang SQ, Thien VK, Chan EWL
    Microb Drug Resist, 2021 Feb;27(2):234-240.
    PMID: 32589487 DOI: 10.1089/mdr.2020.0178
    Aims: Currently, limited antibiotics are available to treat methicillin-resistant Staphylococcus aureus (MRSA) infections. One approach is the use of adjuvants in antibiotic therapy. 1,4-Naphthoquinones are naturally occurring alkaloids shown to have antibacterial properties. The objective of this study is to investigate the synergy between 1,4-naphthoquinone and selected β-lactam antibiotics and to evaluate the potential use of 1,4-naphthoquinone as an adjuvant in antibiotic treatment against MRSA infections. Methods: The antibacterial activity of 1,4-naphthoquinone and plumbagin was tested against nine pathogenic bacterial strains using the microdilution broth method. The interactions between 1,4-naphthoquinone and three antibiotics (cefuroxime, cefotaxime, and imipenem) were estimated by calculating the fractional inhibitory concentration of the combination. Results: The compounds 1,4-naphthoquinone and plumbagin exhibited a broad range of bacteriostatic and bactericidal effects against both Gram-positive and Gram-negative bacteria. The interaction between 1,4-naphthoquinone and imipenem, cefuroxime, and cefotaxime was synergistic against methicillin-sensitive Staphylococcus aureus and MRSA clinical strains. Against ATCC-cultured MRSA, a synergistic effect was observed between 1,4-naphthoquinone and cefotaxime. However, combination with imipenem only produced an additive effect, and an antagonistic action was observed between 1,4-naphthoquinone and cefuroxime. Conclusions: Although individually less potent than common antibiotics, 1,4-naphthoquinone acts synergistically with imipenem, cefuroxime, and cefotaxime against MRSA clinical strains and could potentially be used in adjuvant-antibiotic therapy against multidrug resistant bacteria.
    Matched MeSH terms: Naphthoquinones/pharmacology*
  19. Exposure to Electrophiles Impairs Reactive Persulfide-Dependent Redox Signaling in Neuronal Cells
    Ihara H, Kasamatsu S, Kitamura A, Nishimura A, Tsutsuki H, Ida T, et al.
    Chem Res Toxicol, 2017 09 18;30(9):1673-1684.
    PMID: 28837763 DOI: 10.1021/acs.chemrestox.7b00120
    Electrophiles such as methylmercury (MeHg) affect cellular functions by covalent modification with endogenous thiols. Reactive persulfide species were recently reported to mediate antioxidant responses and redox signaling because of their strong nucleophilicity. In this study, we used MeHg as an environmental electrophile and found that exposure of cells to the exogenous electrophile elevated intracellular concentrations of the endogenous electrophilic molecule 8-nitroguanosine 3',5'-cyclic monophosphate (8-nitro-cGMP), accompanied by depletion of reactive persulfide species and 8-SH-cGMP which is a metabolite of 8-nitro-cGMP. Exposure to MeHg also induced S-guanylation and activation of H-Ras followed by injury to cerebellar granule neurons. The electrophile-induced activation of redox signaling and the consequent cell damage were attenuated by pretreatment with a reactive persulfide species donor. In conclusion, exogenous electrophiles such as MeHg with strong electrophilicity impair the redox signaling regulatory mechanism, particularly of intracellular reactive persulfide species and therefore lead to cellular pathogenesis. Our results suggest that reactive persulfide species may be potential therapeutic targets for attenuating cell injury by electrophiles.
    Matched MeSH terms: Naphthoquinones/toxicity; Naphthoquinones/chemistry
  20. Rhinacanthin C ameliorates hyperglycaemia, hyperlipidemia and pancreatic destruction in streptozotocin-nicotinamide induced adult male diabetic rats
    Adam SH, Giribabu N, Rao PV, Sayem AS, Arya A, Panichayupakaranant P, et al.
    Eur J Pharmacol, 2016 Jan 15;771:173-90.
    PMID: 26703866 DOI: 10.1016/j.ejphar.2015.12.028
    Effect of Rhinacanthin C on hyperglycaemia, hyperlipidemia and pancreatic dysfunction in diabetes was investigated. In-vitro effect of Rhinacanthin C on glucose uptake was studied in 3T3-L1 cell line. Meanwhile, in-vivo effect of 28-days treatment with 5mg/kg/day or 20mg/kg/day Rhinacanthin C was studied in streptozotocin-nicotinamide induced male diabetic rats. Following completion of treatment, fasting blood glucose (FBG), HbA1c, insulin and lipid profile levels were measured by biochemical assays. Histopathological changes in pancreas were observed by light microscopy while levels of pancreatic oxidative stress were determined by enzymatic assays. Expression of insulin, TNFα, Ikkβ and caspase-3 in pancreas were quantified by immunohistochemistry. Molecular docking was used to identify interactions between Rhinacathin C with SOD or GPx enzymes. Dose-dependent increase in glucose uptake was observed with increasing doses of Rhinacathin C. Plasma FBG, HbA1c and lipid profile except LDL levels and pancreatic malonaldehyde level were reduced but serum insulin and pancreatic anti-oxidative enzymes (SOD, CAT and GPx) levels were increased in diabetic rats receiving Rhinacanthin C treatment. Decreased pancreatic histopathological changes with higher pancreatic insulin and Glut-2 levels but lower TNFα, Ikkβ and caspase-3 levels were observed in diabetic rats receiving Rhinacanthin C (P<0.05 compared to non-treated diabetic rats). In diabetic rats which received Rhinacathin C, changes in the above parameters did not achieve the value in non-diabetic rats. Docking shows Rhinacathin C possesses high degree interactions with SOD and GPx. By possessing these effects, Rhinacanthin C could be used as agent to alleviate pancreatic and other complications in diabetes.
    Matched MeSH terms: Naphthoquinones/therapeutic use*
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