Comparative binding affinities of flavonoid phytochemicals with bovine serum albumin

Dietary flavonoids show beneficial effects in the prevention of chronic diseases. However, flavonoid bioavailability is poor, probably due to their interaction with serum albumins. In the current work, the binding interactions of eight related flavonoids, sharing a similar core structure, with bovine serum albumin [BSA] were investigated by fluorescence spectroscopy. The binding affinities of the flavonoids with BSA were in the order hesperetin [KA=5.59 × 10[5]] > quercetin [4.94 × 10[5]] > naringenin [3.04 × 10[5]] > isoquercitrin [4.66 × 10[4]] > icariin [3.60 × 10[4]] > rutin [1.65 × 10[4]] > hesperidin [2.50 × 10[3]] > naringin [8.70 × 10[2]]. The associations of specific structural components of the flavonoids with their binding properties to BSA were also explored and hydrophobicity, functional group substituents, steric hindrance effects and the spatial arrangements of substituents seem to be the key factors for the affinities of flavonoids towards BSA. The results from the current work contribute to a better understanding of the transport of flavonoids in plasma and helping predict their physiological functions based on their intrinsic structures

Down-regulation of Ech1 decreases the adhesion ability of mouse hepatocarcinoma Hca-F cells / 中华肝脏病杂志

To examine the differential expression pattern of Ech1 protein in mouse Hca-F and Hca-P hepatocarcinoma cell lines with high and low rates of lymphatic metastasis, respectively, and to investigate the relationships between Ech1 expression and adhesion of Hca-F cells. Fluorescence two-dimensional difference in-gel electrophoresis (2D DIGE) and mass spectrometry were used to detect Ech1 expression. Ech1 gene silencing was achieved by stable transfection of Hca-F cells with a plasmid vector harboring short hairpin RNA (shRNA) targeting Ech1, pGPU6/GFP/Neo-shRNA-Ech1. Ech1 mRNA and protein expressions were detected by real-time quantitative polymerase chain reaction (qRT-PCR) and Western blotting analysis, respectively. Adhesive properties of cells were assessed by hematoxylin-eosin staining and fluorimetric detection of extracellular matrix (ECM) proteins. Endogenous Ech1 protein level was remarkably higher in the highly metastatic Hca-F cell line than in the Hca-P cell line (2.7-fold by 2D DIGE; 1.5-fold by Western blotting). shRNA-induced silencing of Ech1 significantly reduced the adhesion ability of Hca-F cells, as evidenced by decreased absorbance values of fibronectin and collagen I (Hca-F cells vs. pGPU6/GFP/Neo-shRNA-Ech1 cells: 1.42+/-0.26 vs. 1.01+/-0.27 and 1.14+/-0.07 vs. 0.90+/-0.09, respectively; P less than 0.05). Down-regulation of Ech1 can inhibit the adhesive capacity of metastatic Hca-F cells.

Investigation on the migration and biologic effects of nano FeOx powders under the exposure of extremely low frequency altering electric magnetic field in human heptoma-bearing nude mice in vivo / 中华肝脏病杂志

To investigate the mechanism and biologic effects of 37 nm magnetic nano FeOx powders (MNPs) on human hepatoma-bearing nude mice. 37 nm MNPs were prepared by coprecipitation methods and then injected into human hepatoma (Bel-7402) bearing-nude mice through the tail vein. After injection of MNPs, the mice were first exposed under static magnetic field and then treated under extremely low frequency altering-electric magnetic field directing to the tumor area. The migration and trafficking of MNPs were determined by MMR. Tumor growth was monitored with calipers every 5 days and tumor volume was calculated on the basis of three-dimensioned measurements. The apoptosis of tumor cells was analyzed by flow cytometry analysis. The expressions of apoptosis-associated proteins Bcl-2, Bax and HSP27 were determined using western-blot analysis. Static magnetic field could direct the migration and trafficking of MNPs to the tumor site with a higher ratio of 98.9%. Extremely Low Frequency Electric-Magnetic Field (EMF) treatment could inhibit the proliferation of tumor cells and prolong the survive time of tumor-bearing mice injected with MNPs. In addition, the survival time of tumor-bearing mice and percentages of prohibition on tumor cell growth were 27.4+/-0.7 days and 37.5+/-0.8% (F = 0.005, P is less than to 0.05), respectively. The results of flow cytometry analyses showed that about 18.1+/-0.6% (F = 0.030, P is less than to 0.05) of tumor cells were induced into early apoptosis. Furthermore, expressions of apoptosis-associated proteins Bcl-2 and Bax were significantly induced by MNPs under EMF treatment. The ratio of Bcl/Bax in both MNPs and EMF treatment group was 0.07+/-0.01, which was much lower than that of control group (0.23+/-0.02) (F = 0.016, P is less than to 0.05). Heat shock protein-27 (Hsp-27) was not significantly induced in different treatment groups. Injection of MNPs with EMF exposure on human hepatoma-bearing nude mice could significantly prolong the survival time, inhibit the tumor proliferation and growth, and induce tumor cells into apoptosis.

Localization and expression of CLIC1 in hepatocarcinoma ascites cell lines with high or low potentials of lymphatic spread / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the localization and expression of CLIC1 in mouse hepatocarcinoma ascites cell lines with different metastatic potentials.</p><p><b>METHODS</b>Mouse hepatocarcinoma ascites models (a high potential of lymphatic metastasis cell line-Hca-F, and a low potential of lymphatic metastasis cell line-Hca-P) were investigated using fluorescent two-dimensional difference-gel electrophoresis (2-D DIGE) and mass spectrometry for detecting the localization and expression of CLIC1. Immunofluorescence, immunocytochemistry and Western blot were used to assess CLIC1 protein status in the two cell lines.</p><p><b>RESULTS</b>CLIC1 expression was obtained in the cytoplasm and plasma membrane of cells in both cell lines. 2-D DIGE showed that CLIC1 was overexpressed in Hca-F cells, 1.6 folds higher than that of the Hca-P cells. Hca-F cells also had a higher integral membrane CLIC1 in the Hca-P cells.</p><p><b>CONCLUSIONS</b>Although CLIC1 expression is detected in both Hca-F and Hca-P cell lines, a higher protein expression level is present in Hca-F cells. CLIC1 may play an important role in tumor metastasis.</p>