Formulation of a Self-Nanoemulsifying Drug Delivery System of Buckwheat Flavonoids and Evaluation of Its Antimicrobial Activity.

This study was aimed at constructing a self-nanoemulsifying drug delivery system of buckwheat flavonoids and evaluating its antimicrobial activity. The construction of the nanoemulsion followed a pseudo-ternary phase diagram, and its particle properties (particle size, zeta potential, and surface morphology) and physicochemical parameters (turbidity, surface tension, pH value, conductivity, encapsulation efficiency, and stability) were evaluated. The antimicrobial potential of buckwheat flavonoids nanoemulsion was determined against Staphylococcus aureus, Escherichia coli, and Candida albicans and compared to the buckwheat flavonoids suspension. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) exhibited that the antimicrobial activity of the nanoemulsions and suspension increased while enhancing the drug concentration, and the antimicrobial activity of nanoemulsion was significantly higher than that of the suspension against those three bacteria. Agar disc diffusion test demonstrated that the inhibition zone diameter of the suspension was about 50% of the nanoemulsion against three bacteria. The time killing assay indicated that the IC50 of the nanoemulsion was significantly lower than that of the suspension. These results indicate that nanoemulsion is a promising drug delivery system, which can improve the antimicrobial activity of buckwheat flavonoids.

[Thickness measurement of ultrathin SiO2 layer on Si by using XPS standard curve].

A new method of standard curve analysis associated with X-ray photoelectron spectroscopy (XPS) is presented for measuring the thickness of ultrathin SiO2 layer on Si substrate. In this method, XPS spectra of series SiO2/Si standard samples with different known thicknesses of silicon oxides are firstly recorded, and then the ratios of Si2p peak heights corresponding to SiO2 and Si, viz. R = H(SiO2/H(Si), are calculated. The known thicknesses of silicon oxides are plotted against the peak height ratios and an XPS standard curve is derived. Under the same experimental conditions, the samples with unknown thicknesses are measured by using XPS technique and then their thicknesses can be obtained from the XPS standard curve. The SiO2 /Si standard samples were provided by authoritative lab with the advanced analytical equipments and rich experiences, and the oxide thicknesses were measured by multiple techniques. The present results show that the standard curve, plotted in terms of accuracy of the oxide thickness from the standard samples, can be used for the thickness measurement for ultrathin SiO2 on Si, and this method is valuable in practice owing to the swiftness, convenience and accuracy.

[Studies on chemical constituents from stem barks of Fraxinus paxiana].

OBJECTIVE: To investigate the chemical constituents of Fraxinus paxiana. METHOD: The chemical constituents were isolated and purified by chromatographic techniques and the structures of the compounds were identified with or by spectroscopic methods. RESULT: Fifteen compounds were obtained from the methanol extract of F. paxiana and their structures were elucidated as esculin (1), esculetin (2), fraxin (3), fraxetin (4), salidroside (5), osmanthuside H (6), liriodendrin (7), 3-(4-beta-D-glucopyranosyloxy-3-methoxy)-phenyl-2E-propenol (8), threo-syringylglycerol (9), euscaphic acid (10), 3-hydroxy-1-(4-hydroxy-3, 5-dimethoxyphenyl)-1-propanone (11), omega-hydroxypropioguaiacone (12), sinapyladehyde (13), betulinic acid (14) and mannitol (15). CONCLUSION: All compounds were obtained from this plant for the first time.

SAHA and/or MG132 reverse the aggressive phenotypes of glioma cells: An in vitro and vivo study.

To elucidate the anti-tumor effects and molecular mechanisms of SAHA (a histone deacetylase inhibitor) and MG132 (a proteasome inhibitor) on the aggressive phenotypes of glioma cells, we treated U87 and U251 cells with SAHA or/and MG132, and detected phenotypes' assays with phenotype-related molecules examined. It was found that SAHA or/and MG132 treatment suppressed proliferation in both concentration- and time-dependent manners, inhibited energy metabolism, migration, invasion and lamellipodia formation, and induced G2 arrest and apoptosis in the glioma cells. The treatment with SAHA increased the expression of acetyl-histones 3 and 4, which were recruited to the promoters of p21, p27, Cyclin D1, c-myc and Nanog to down-regulate their transcriptional levels. Expression of acetyl-histones 3 and 4 was higher in gliomas than normal brain tissues. Both drugs' exposure suppressed tumor growth in nude mice by inducing apoptosis and inhibiting proliferation, but increased serum aminotransferase and creatinine. These results indicated that SAHA and/or MG132 may suppress the aggressive phenotypes of glioma cells. They might be employed to treat the glioma if both hepatic and renal injuries are prevented.

The roles of ING5 in gliomas: a good marker for tumorigenesis and a potential target for gene therapy.

To elucidate the anti-tumor effects and molecular mechanisms of ING5 on glioma cells, we overexpressed it in U87 cells, and examined the phenotypes and their relevant molecules. It was found that ING5 overexpression suppressed proliferation, energy metabolism, migration, invasion, and induced G2/M arrest, apoptosis, dedifferentiation, senescence, mesenchymal- epithelial transition and chemoresistance to cisplatin, MG132, paclitaxel and SAHA in U87 cells. There appeared a lower expression of N-cadherin, Twist, Slug, Zeb1, Zeb2, Snail, Ac-H3, Ac-H4, Cdc2, Cdk4 and XIAP, but a higher expression of Claudin 1, Histones 3 and 4, p21, p53, Bax, ß-catenin, PI3K, Akt, and p-Akt in ING5 transfectants. ING5 overexpression suppressed tumor growth of U87 cells in nude mice by inhibiting proliferation and inducing apoptosis. Down-regulated ING5 expression was closely linked to the tumorigenesis and histogenesis of glioma. These data indicated that ING5 expression might be considered as a good marker for the tumorigenesis and histogenesis of gliomas. It might be employed as a potential target for gene therapy of glioma. PI3K/Akt or ß-catenin/TCF-4 activation might be positively linked to chemotherapeutic resistance, mediated by ING5.

Expression, correlation, and prognostic value of TRAF2 and TRAF4 expression in malignant plural effusion cells in human breast cancer.

BACKGROUND: TRAF2 and TRAF4, members of the tumor necrosis factor receptor- associated factor family of intracellular signal transduction proteins, are associated with breast cancer progression and metastasis. METHODS: We collected malignant serous effusion cells from the patients with breast cancer (n = 46). Cell blocks prepared from plural effusions (n = 46) and primary breast cancer (n = 50), lymph node metastases (n = 50), and normal breast tissue specimens (n = 30). The immunohistochemistry was performed for the detection of TRAF2 and TRAF4 expression with the correlation of their expression with clinicopathological parameters and survival rate analyzed. RESULTS: Compared with normal breast tissues, TRAF2 expression was upregulated, and nuclear TRAF4 expression was downregulated in malignant pleural effusion cells, primary tumors, and lymph node metastases (P < 0.05). Multivariate analysis revealed TRAF2 expression in pleural effusions was associated with the molecular/pathological type, venous invasion, and lymph node metastasis, while nuclear TRAF4 expression was associated with age, tumor size, venous invasion, and lymph node metastasis, clinical staging, molecular/pathological subtype and p53 status (P < 0.05). There was a significant positive correlation between TRAF2 and TRAF4 expression levels in malignant pleural effusion cells (r = 0.937; P < 0.01). Kaplan-Meire analysis demonstrated a close correlation of TRAF2 and TRAF4 expression in malignant pleural effusion cells with cumulative overall survival (P < 0.05). CONCLUSION: TRAF2 and nuclear TRAF4 expression in malignant pleural effusion cells may represent potential prognostic factors and biomarkers of invasion and metastasis in breast cancer.

Anti-tumoral effects of a trypsin inhibitor derived from buckwheat in vitro and in vivo.

Native buckwheat, a common component of food products and medicine, has been observed to inhibit cancer cell proliferation in vitro. The aim of the present study was to evaluate the in vitro and in vivo anti-tumoral effects of recombinant buckwheat trypsin inhibitor (rBTI) on hepatic cancer cells and the mechanism of apoptosis involved. Apoptosis in the H22 cell line induced by rBTI was identified using MTT assays, DNA electrophoresis, flow cytometry, morphological observation of the nuclei, measurement of cytochrome C and assessment of caspase activation. It was identified that rBTI decreases cell viability by inducing apoptosis, as evidenced by the formation of apoptotic bodies and DNA fragmentation. rBTI-induced apoptosis occurred in association with mitochondrial dysfunction, leading to the release of cytochrome C from the mitochondria to the cytosol, as well as the activation of caspase-3, -8 and -9. In conclusion, the results of the present study suggested that rBTI specifically inhibited the growth of the H22 hepatic carcinoma cell line in vitro and in vivo in a concentration-dependent and time-dependent manner, while there were minimal effects on the 7702 normal liver cell line. In addition, rBTI­induced apoptosis in H22 cells was, at least in part, mediated by a mitochondrial pathway via caspase-9.

Suppressive role of miR-502-5p in breast cancer via downregulation of TRAF2.

TRAF2 promotes cancer cell survival, proliferation and metastasis through the NF-κB pathway by directly interacting with various TNF recepors. However, the molecular mechanism of TRAF2 dysregulation in breast cancer remains to be elucidated. In the present study, miR-502-5p was predicted as a potential regulator of TRAF2. miR-502-5p was significantly downregulated in breast cancer tissues when compared to the level in paired normal breast tissues. The breast cancer cell lines including MCF-7 and MDA-MB-231 expressed a lower level of miR-502-5p when compared to the level in the non-malignant breast epithelial cell line MCF-10A. In vitro, miR-502-5p enhanced early apoptosis and inhibited proliferation of breast cancer cells. Luciferase reporter assay results showed that miR-502-5p could bind to the 3'-untranslated region of the TRAF2 gene, thus, exerting an inhibitory effect on TRAF2. Furthermore, silencing of TRAF2 exhibited effects similar to those of exogenous miR­502-5p, while overexpression of TRAF2 partially abrogated miR-502-5p-mediated suppression in breast cancer cells. In conclusion, miR-502-5p may act as a tumor-suppressor gene by targeting oncogenic TRAF2 in breast cancer and, therefore, may be a potential diagnostic and anticancer therapeutic marker for breast cancer.

[Effects of elevated CO2 on the Cd uptake and root morphology of different rice varieties under cadmium stress].

A hydroponic experiment was conducted to study the effects of elevated CO2 on the Cd uptake and root morphology of rice varieties Rongyou-398 (RY) and Yueza-889 (YZ) under different levels of Cd stress. Low levels (5, 10, and 20 micromol x L(-1)) Cd stress increased the biomass of the two rice varieties significantly, while high levels (> 50 micromol x L(-1)) Cd stress was in adverse. Elevated CO2 increased the varieties dry biomass significantly, and increased the stem Cd concentration of YZ but decreased that of RY. Under the stress of 5-200 micromol Cd x L(-1), elevated CO2 increased the proportion of active root length in total root length of YZ but decreased that of RY, which could be one of the main reasons for the difference in the Cd uptake of the two varieties under Cd stress.