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Hwang S.Y.,Hanyang University | Hwang S.Y.,Hanmi Pharmaceutics Research Center | Cho S.H.,Hanyang University | Cho S.H.,Korean Research Institute of Biosciences and Biotechnology | And 3 more authors.
Apoptosis | Year: 2011

The objective of this study was to propose a feasibility of a cellular imaging assay as an alternative to the conventional cytotoxicity assay, such as MTS assay, for apoptosis monitoring. As an apoptosis monitoring parameter, affinity interaction between phosphatidylserine (PS) and annexin V was chosen. First, the specific binding affinity between annexin V and PS in phospholipid bilayers consisting of various molar (0-15%) composition of PS was measured using a surface plasmon resonance biosensor. As PS composition increased, the binding level of annexin V increased proportionally. Second, various concentrations (0.1-10 lM) of staurosporine were used as to induce apoptosis and introduced to MCF-7 breast carcinoma cells. The cellular fluorescence images from annexin V-FITC conjugate were obtained by confocal microscopy, and their fluorescence intensities were quantified by image scanning. Dose-apoptosis (or cell death) relationships were very similar to those from MTS and FACS assays. In summary, our cellular imaging method could serve as a quicker and simpler alternative to MTS (end point assay) and FACS (flow cytometry) to screen potential apoptosis inducers. © 2011 Springer Science+Business Media, LLC.

Nguyen T.D.,Vietnam Academy of Science and Technology | Duong T.T.,Vietnam Academy of Science and Technology | Le T.P.Q.,Vietnam Academy of Science and Technology | Chau V.M.,Vietnam Academy of Science and Technology | And 4 more authors.
Medicinal Chemistry Research | Year: 2011

Several Vietnamese freshwater cyanobacteria were collected and evaluated for their effects on the transcriptional nuclear factor κB (NF-κB) which are involving in the cancer and inflammatory diseases. Five extraction conditions were tested and a solution of 2% acetic acid in methanol provided highest yield of extract from bacterial biomass. The Microcystis aeruginosa TC-1 and TC-3 strains showed strong NF-κB inhibitory activity with IC 50 values of 6.1 and 5.3 μg/ml, respectively. Moreover, all tested cyanobacteria exhibited cytotoxicity on human cervical cancer HeLa cells in a dose-dependent manner. Ergosterol (1) isolated from M. aeruginosa TC-3 strains strongly inhibited NF-κB activation with IC50 values of 0.91 μg/ml. © Springer Science+Business Media, LLC 2010.

Dat N.T.,Korean Research Institute of Biosciences and Biotechnology | Dat N.T.,Vietnam Academy of Science and Technology | Jin X.,Korean Research Institute of Biosciences and Biotechnology | Hong Y.-S.,Korean Research Institute of Biosciences and Biotechnology | Lee J.J.,Korean Research Institute of Biosciences and Biotechnology
Journal of Natural Products | Year: 2010

Hypoxia-inducible factor-1 and nuclear factor-κB have become important targets in cancer treatment due to their critical role in the regulation of genes involved in tumorigenesis. Bioassay-guided fractionation of the methanol extract of Trichosanthes kirilowii seeds led to the isolation of a naturally rare isoaurone, 4′,6-dihydroxy-4-methoxyisoaurone (1), together with three known compounds, cucurbitacin B (2), 6-(3-hydroxy-4-methoxystyryl)-4- methoxy-2H-pyran-2-one (3), and blumenol A (4). All compounds inhibited HIF-1 and NF-κB activities in reporter assays. Compounds 1-3 potently inhibited HIF-1α accumulation and VEGF secretion under hypoxic condition. These results suggest that the tumor cell growth inhibitory activity of T. kirilowii is likely associated with the inhibition of HIF-1 and NF-κB activities. © 2010 The American Chemical Society and American Society of Pharmacognosy.

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