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  • 1
    Language: English
    In: Antiviral Research, January 2013, Vol.97(1), pp.41-48
    Description: ► 22 Flavonoids were examined for activity against H5N1 influenza A viruses. ► Biochanin A and baicalein exerted the highest potency. ► Biochanin A and baicalein interfered with H5N1 replication. ► Biochanin A and baicalein interfered with virus-induced cytokine expression. ► Biochanin A and baicalein differ in their molecular antiviral mechanisms. From a panel of 22 flavonoids, we identified six compounds (apigenin, baicalein, biochanin A, kaempferol, luteolin, naringenin) that inhibited influenza A nucleoprotein production in human lung epithelial (A549) cells infected with the highly pathogenic avian influenza H5N1 virus strain A/Thailand/Kan-1/04 in non-toxic concentrations. Baicalein ( : 18.79 ± 1.17 μM, selectivity index 5.82) and biochanin A ( 8.92 ± 1.87 μM, selectivity index 5.60) were selected for further experiments. Both compounds reduced H5N1 infectious titres (baicalein 40 μM: 29-fold reduction, biochanin A 40 μM: 55-fold reduction after infection at MOI 0.01), virus-induced caspase 3 cleavage, nuclear export of viral RNP complexes, and enhanced the effects of the neuraminidase inhibitor zanamivir. Biochanin A and baicalein also inhibited the replication of the H5N1 strain A/Vietnam/1203/04. Time of addition experiments indicated that both compounds interfere with H5N1 replication after the adsorption period. Further mechanistic investigations revealed clear differences between these two flavonoids. Only baicalein interfered with the viral neuraminidase activity (39 ± 7% inhibition at 100 μM, the maximum concentration tested). In contrast to baicalein, biochanin A affected cellular signalling pathways resulting in reduced virus-induced activation of AKT, ERK 1/2, and NF-kB. Moreover, biochanin A inhibited the virus-induced production of IL-6, IL-8, and IP-10 while baicalein inhibited IL-6 and IL-8 production without affecting IP-10 levels. In primary human monocyte-derived macrophages, only baicalein but not biochanin A impaired H5N1 virus replication. Both flavonoids interfered with the H5N1-induced production of IL-6, IP-10, and TNF-α but not of IL-8 in macrophages. These findings indicate that closely related flavonoids can exert anti-H5N1 effects by different molecular mechanisms.
    Keywords: H5n1 ; Biochanin A ; Baicalein ; Antiviral ; Anti-Inflammatory ; Flavonoid ; Medicine ; Biology
    ISSN: 0166-3542
    E-ISSN: 1872-9096
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  • 2
    Language: English
    In: PLoS ONE, 2011, Vol.6(5), p.e19705
    Description: Glycyrrhizin is known to exert antiviral and anti-inflammatory effects. Here, the effects of an approved parenteral glycyrrhizin preparation (Stronger Neo-Minophafen C) were investigated on highly pathogenic influenza A H5N1 virus replication, H5N1-induced apoptosis, and H5N1-induced pro-inflammatory responses in lung epithelial (A549) cells. Therapeutic glycyrrhizin concentrations substantially inhibited H5N1-induced expression of the pro-inflammatory molecules CXCL10, interleukin 6, CCL2, and CCL5 (effective glycyrrhizin concentrations 25 to 50 µg/ml) but interfered with H5N1 replication and H5N1-induced apoptosis to a lesser extent (effective glycyrrhizin concentrations 100 µg/ml or higher). Glycyrrhizin also diminished monocyte migration towards supernatants of H5N1-infected A549 cells. The mechanism by which glycyrrhizin interferes with H5N1 replication and H5N1-induced pro-inflammatory gene expression includes inhibition of H5N1-induced formation of reactive oxygen species and (in turn) reduced activation of NFκB, JNK, and p38, redox-sensitive signalling events known to be relevant for influenza A virus replication. Therefore, glycyrrhizin may complement the arsenal of potential drugs for the treatment of H5N1 disease.
    Keywords: Research Article ; Medicine ; Infectious Diseases ; Pharmacology
    E-ISSN: 1932-6203
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  • 3
    Language: English
    In: International Journal of Pharmaceutics, 2011, Vol.406(1), pp.128-134
    Description: Folic acid has been previously demonstrated to mediate intracellular nanoparticle uptake. Here, we investigated cellular uptake of folic acid-conjugated human serum albumin nanoparticles (HSA NPs). HSA NPs were prepared by desolvation and stabilised by chemical cross-linking with glutaraldehyde. Folic acid was covalently coupled to amino groups on the surface of HSA NPs by carbodiimide reaction. Preparation resulted in spherical HSA NPs with diameters of 239 ± 26 nm. As shown by size exclusion chromatography, 7.40 ± 0.90 μg folate was bound per mg HSA NPs. Cellular NP binding and uptake were studied in primary normal human foreskin fibroblasts (HFFs), the human neuroblastoma cell line UKF-NB-3, and the rat glioblastoma cell line 101/8 by fluorescence spectrophotometry, flow cytometry, and confocal laser scanning microscopy. Covalent conjugation of folic acid to HSA NPs increased NP uptake into cancer cells but not into HFFs. Free folic acid interfered with cancer cell uptake of folic acid-conjugated HSA NPs but not with uptake of folic acid-conjugated HSA NPs into HFFs. These data suggest that covalent linkage of folic acid can specifically increase cancer cell HSA NP uptake.
    Keywords: Nanoparticles ; Human Serum Albumin (HSA) ; Folic Acid ; Folate Receptor ; Cancer Targeting ; Pharmacy, Therapeutics, & Pharmacology
    ISSN: 0378-5173
    E-ISSN: 1873-3476
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  • 4
    Language: English
    In: Medical Microbiology and Immunology, 2011, Vol.200(1), pp.53-60
    Description: Influenza A virus infection of macrophages and virus-induced pro-inflammatory gene expression are regarded to contribute to severity of influenza A virus-caused diseases. Although some data are available on cytokine production by influenza A virus-infected macrophages, systematic comparisons of the virus types are currently considered to be of high relevance in humans (pandemic H1N1/2009, seasonal H1N1, seasonal H3N2, highly pathogenic avian influenza H5N1) on pro-inflammatory potential, and relevant underlying cellular signalling events are missing. Here, we show that the infection of human monocyte-derived macrophages with pandemic H1N1/2009 (A/HH/01/2009), seasonal H1N1/1999 (A/New Caledonia/20/99), seasonal H3N2/2004 (A/California/7/2004) or highly pathogenic H5N1/2004 (A/Thailand/1(Kan-1)/04) results in similar infection rates. However, the investigated H1N1 strains caused delayed and decreased apoptosis in comparison with H3N2/2004 or H5N1/2004. Moreover, human macrophage infection with H3N2/2004 or H5N1/2004 but not with H1N1 viruses was associated with pronounced pro-inflammatory cytokine production and activation of relevant mitogen-activated protein kinase pathways as indicated by phosphorylation of p38, JNK and ERK 1/2. These findings are in line with clinical observations indicating enhanced disease severity in H3N2- or H5N1-infected patients compared to individuals infected with pandemic H1N1/2009 or seasonal H1N1.
    Keywords: Influenza A ; MAPK ; Cytokines ; Seasonal influenza ; H5N1 ; Pandemic H1N1/2009
    ISSN: 0300-8584
    E-ISSN: 1432-1831
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  • 5
    Language: English
    In: BMC research notes, 23 June 2014, Vol.7, pp.384
    Description: Different flavonoids are known to interfere with influenza A virus replication. Recently, we showed that the structurally similar flavonoids baicalein and biochanin A inhibit highly pathogenic avian H5N1 influenza A virus replication by different mechanisms in A549 lung cells. Here, we investigated the effects of both compounds on H5N1-induced reactive oxygen species (ROS) formation and the role of ROS formation during H5N1 replication. Baicalein and biochanin A enhanced H5N1-induced ROS formation in A549 cells and primary human monocyte-derived macrophages. Suppression of ROS formation induced by baicalein and biochanin A using the antioxidant N-acetyl-L-cysteine strongly increased the anti-H5N1 activity of both compounds in A549 cells but not in macrophages. These findings emphasise that flavonoids induce complex pharmacological actions some of which may interfere with H5N1 replication while others may support H5N1 replication. A more detailed understanding of these actions and the underlying structure-activity relationships is needed to design agents with optimised anti-H5N1 activity.
    Keywords: Acetylcysteine ; Flavanones -- Pharmacology ; Flavonoids -- Pharmacology ; Genistein -- Pharmacology ; Influenza A Virus, H5n1 Subtype -- Drug Effects ; Oxidative Stress -- Drug Effects
    E-ISSN: 1756-0500
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  • 6
    In: Evidence-Based Complementary and Alternative Medicine, 2015, Vol.2015, 8 pages
    Description: The antioxidant and antibacterial assays against clinically isolated and of the extracts prepared by decoction and ethanolic reflux of different parts of Chettaphangki ( Zipp. ex Span), including the leaves, roots, and stems, using 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging assay and disc diffusion method were conducted. Quantitative analysis of total phenolic and total flavonoid contents in the extracts using spectrophotometric methods was also performed. Finally, phytochemical screening by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) was conducted. Leaf ethanolic reflux extract (100 g) contained the highest total phenolic and total flavonoid contents of 7.21 ± 0.28 g gallic acid equivalent (GAE) and 11.51 ± 2.02 g rutin equivalent (RE), respectively. Chettaphangki extracts promoted low antioxidant activity with EC values in the range of 0.27–0.48 mg/mL. Extracts and fractions from the roots and stems of this plant promoted low to intermediate antibacterial activity against with the inhibition zones between 7 and 14 mm. The chromatographic data suggested that the leaf extracts of contained rutin while the root and stem extracts contained scopoletin and chettaphanin I. Rutin promoted strong antioxidant activity while chettaphanin I showed low antibacterial activity against .
    Keywords: High-Performance Liquid Chromatography ; Flavonoids ; Antioxidants ; Data Processing ; Antibacterial Activity ; Leaves ; Roots ; Rutin ; Stems ; Gallic Acid ; Phenolic Compounds ; Spectrophotometry ; Diffusion ; Plant Extracts ; Streptococcus Suis ; Staphylococcus Intermedius ; Antibiotics & Antimicrobials ; Miscellaneous;
    ISSN: 1741-427X
    E-ISSN: 1741-4288
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  • 7
    Language: English
    In: Molecules, 01 April 2016, Vol.21(4), p.446
    Description: Oroxylum indicum, which is called Pheka in Thai, is a traditional Thai plant in the Bignoniaceae family with various ethnomedical uses such as as an astringent, an anti-inflammatory agent, an anti-bronchitic agent, an anti-helminthic agent and an anti-microbial agent. The young fruits of this plant have also been consumed as vegetables. However, there has been no report concerning its antibacterial activities, especially activities related to clinically isolated pathogenic bacteria and the in vitro antioxidant effects of this plant. Therefore, the extracts from O. indicum fruits and seeds collected from different provinces in Thailand were prepared by decoction and maceration with ethanol and determined for their in vitro antibacterial effects on two clinically isolated bacteria, Streptococcus suis and Staphylococcus intermedius, using disc diffusion assay. Ethanol extracts from O. indicum fruits collected from Nakorn Pathom province at the concentration of 1000 mg/mL exhibited intermediate antibacterial activity against S. intermedius with an inhibition zone of 15.11 mm. Moreover, it promoted moderate inhibitory effects on S. suis with an inhibition zone of 14.39 mm. The extracts prepared by maceration with ethanol promoted higher antibacterial activities than those prepared with water. The ethanol extract from the seeds of this plant, purchased in Bangkok, showed stronger in vitro antioxidant activities than the other extracts, with an EC50 value of 26.33 µg/mL. Phytochemical analysis suggested that the seed ethanol extract contained the highest total phenolic and flavonoid contents (10.66 g% gallic acid equivalent and 7.16 g% quercetin equivalent, respectively) by a significant amount. Thin layer chromatographic analysis of the extracts showed the chromatographic band that could correspond to a flavonoid baicalein. From the results, extracts from O. indicum fruits have an in vitro antioxidant effect, with antibacterial potential, on clinically pathologic bacteria and they contain an antioxidant flavonoid which could be developed for medicinal and pharmaceutical purposes in the future.
    Keywords: Antibacterial ; Antioxidant ; Oroxylum Indicum ; Streptococcus Suis ; Staphylococcus Intermedius ; Dpph ; Disc Diffusion ; TLC ; Total Phenolic ; Total Flavonoid ; Baicalein ; Chemistry
    E-ISSN: 1420-3049
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  • 8
    Language: English
    In: Medical Microbiology and Immunology, 2010, Vol.199(4), pp.291-297
    Description: Hypercytokinaemia is thought to contribute to highly pathogenic H5N1 influenza A virus disease. Glycyrrhizin is known to exert immunomodulatory and anti-inflammatory effects and therefore a candidate drug for the control of H5N1-induced pro-inflammatory gene expression. Here, the effects of an approved parenteral glycyrrhizin preparation were investigated on H5N1 virus replication, H5N1-induced pro-inflammatory responses, and H5N1-induced apoptosis in human monocyte-derived macrophages. Glycyrrhizin 100 μg/ml, a therapeutically achievable concentration, impaired H5N1-induced production of CXCL10, interleukin 6, and CCL5 and inhibited H5N1-induced apoptosis but did not interfere with H5N1 replication. Global inhibition of immune responses may result in the loss of control of virus replication by cytotoxic immune cells including natural killer cells and cytotoxic CD8 + T-lymphocytes. Notably, glycyrrhizin concentrations that inhibited H5N1-induced pro-inflammatory gene expression did not affect cytolytic activity of natural killer cells. Since H5N1-induced hypercytokinaemia is considered to play an important role within H5N1 pathogenesis, glycyrrhizin may complement the arsenal of potential drugs for the treatment of H5N1 disease.
    Keywords: Glycyrrhizin ; H5N1 ; Cytokines ; Monocyte-derived macrophages
    ISSN: 0300-8584
    E-ISSN: 1432-1831
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  • 9
    Language: English
    In: Molecules, 01 May 2019, Vol.24(10), p.1937
    Description: Oroxylum indicum is a medicinal plant in Thailand, which has been used as a tonic and for the treatment of various diseases. Extracts from various parts of O. indicum were reported as promoting in vitro antioxidant and antibacterial effects. Phytochemical analysis suggested that this plant contained some flavones. O. indicum fruit and seed water and ethanol extracts and their major flavonoids including baicalein, baicalin, and chrysin were tested for in vitro antibacterial activities on four clinical isolated bacteria, namely, Staphylococcus intermedius, Streptococcus suis, Pseudomonas aeruginosa, and β-Escherichia coli, using a broth micro-dilution assay. The amounts of these three major flavonoids were also quantitatively analyzed using the high-performance liquid chromatographic (HPLC) method. O. indicum fruit ethanol extract from Nakhon Pathom province (OFNE) promoted the strongest antimicrobial activity against four clinical pathogenic bacteria, including S. intermedius (IC50 = 1.30 mg/mL), S. suis (13.59% inhibition at 7.81 mg/mL), P. aeruginosa (IC50 = 39.20 mg/mL), and β-E. coli (IC50 = 66.85 mg/mL). Baicalin showed high in vitro antibacterial effect to all tested bacteria. From the optimized and validated HPLC method, baicalin, baicalein, and chrysin contents in O. indicum extracts were 0.19 ± 0.00 − 9.45 ± 0.13, 0.14 ± 0.00 − 1.27 ± 0.02, and 0.02 ± 0.00 − 0.96 ± 0.02 g/100 g extract, respectively. Baicalin was found to be the major compound in O. indicum seed extract followed by baicalein, whereas chrysin was found in lower amounts than the amounts of the other two flavonoids in all O. indicum extracts.
    Keywords: Oroxylum Indicum ; Baicalin ; Baicalein ; Chrysin ; Staphylococcus Intermedius ; Streptococcus Suis ; Broth Micro-Dilution Assay ; Hplc ; Chemistry
    E-ISSN: 1420-3049
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  • 10
    Language: English
    In: Journal of Medical Virology, December 2003, Vol.71(4), pp.532-539
    Description: The dengue virus consists of four antigenically related but distinct viruses, termed Dengue virus 1–4 (DEN 1–4). We have established that the dengue virus loses infectivity over time in solution in an exponentially declining manner. The four strains examined (one from each serotype) have half‐lives that range from 2.5 to 7.5 hr in defined medium. The half‐life is temperature and pH‐dependent and is affected by the nature of the host cell in which it is produced, but is not dependent upon the presence of either Mg ions or chelating agents. Electron microscopy (EM) of solutions of the dengue virus show almost complete virus aggregation after 24 hr at room temperature, while RT‐PCR shows an intact RNA genome. These results show that the solution environment of the dengue virus is an important determinant of dengue virus infectivity. J. Med. Virol. 71:532–539, 2003. © 2003 Wiley‐Liss, Inc.
    Keywords: Aggregation ; Electron Microscopy ; Flavivirus ; Infection ; Serotype
    ISSN: 0146-6615
    E-ISSN: 1096-9071
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