Heartwood of Dalbergia cochinchinensis: 4,7,2'-Trihydroxy-4'-methoxyisoflavanol and 6,4'-Dihydroxy-7-methoxyflavane Reduce Cytokine and Chemokine Expression In Vitro.

Dalbergia cochinchinensis has been widely used in traditional medicine because of its flavonoids; however, the impact of the flavonoids to modulate the inflammatory response to oral cells remains to be described. For this aim, we isolated 4,7,2'-trihydroxy-4'-methoxyisoflavanol (472T4MIF) and 6,4'-dihydroxy-7-methoxyflavane (64D7MF) from the heartwood of D. cochinchinensis and confirmed the chemical structure by nuclear magnetic resonance. We show here that both flavonoids are inhibitors of an inflammatory response of murine RAW 264.7 inflammatory macrophages stimulated by LPS. This is indicated by interleukin (IL)1, IL6, and chemokine CCL2 production besides the phosphorylation of p65. Consistently, in primary murine macrophages, both flavonoids decreased the inflammatory response by lowering LPS-induced IL1 and IL6 expression. To introduce oral cells, we have used human gingival fibroblasts and provoked the inflammatory response by exposing them to IL1ß and TNFα. Under these conditions, 472T4MIF, but not 64D7MF, reduced the expression of chemokines CXCL1 and CXCL2. Taken together, we identified two flavonoids that can reduce the expression of cytokines and chemokines in macrophages and fibroblastic cells.

[Studies on technology optimization for extraction and purification of total flavones from root bark of Artocarpus styracifolius].

OBJECTIVE: To study the technology optimization for extraction and purification of total flavones from root bark of Artocarpus styracifolius. METHODS: The optimum extraction conditions were investigated by the contents of the total flavones, using orthogonal test; Static adsorption capacity and desorption rate were employed as examine items for the screening of optimum macroporous resin and optimum technology for the purification of total flavones with selected macroporous were also investigated. RESULTS: The optimum extraction conditions were as follows: using 60% alcohol of seven times than amounts of original material soaking 12 hours,extracting once with hot reflux method at 50 degrees C. HPD-500 type macroporous resin showed better adsorption and desorption property. The optimum purification conditions were as follows: the sample solution was prepared at the concentration of 50.0 mg/mL, subjected to HPD-500 type macroporous resin column chromatography with a load ratio of 22.0 mg total flavones per gram of resin. After standing for 1 hour, the column was eluted with 4 BV water before being eluted with 4 BV 80% alcohol. The purity of the product was 86.4%, which enhanced the content of total flavones by 533%. CONCLUSION: The optimum conditions for extraction and purification of total flavones from root bark of Artocarpus styractifolius are convenient and practical, and could be used as a reference for industrial production.

Interaction of insecticides with mammalian P-glycoprotein and their effect on its transport function.

We studied the effects of four commonly used insecticides (methylparathion, endosulfan, cypermethrin and fenvalerate) on P-glycoprotein isolated from multidrug-resistant cells. All the pesticides stimulated P-glycoprotein ATPase activity, with maximum stimulation of up to 213% in a detergent-solubilized preparation, and up to 227% in reconstituted liposomes. The ATPase stimulation profiles were biphasic, displaying lower stimulation, and in the case of methylparathion, inhibition of activity, at higher insecticide concentrations. Quenching of the intrinsic Trp fluorescence of purified P-glycoprotein was used to quantitate insecticide binding; the estimated K(d) values fell in the range 4-6 microM. Transport of the fluorescent substrate tetramethylrosamine (TMR) into proteoliposomes containing P-glycoprotein was monitored in real time. The TMR concentration gradient generated by the transporter was collapsed by the addition of insecticides, and prior addition of these compounds prevented its formation. The rate of TMR transport was inhibited in a saturable fashion by all the compounds, indicating that they compete with the substrate for membrane translocation. Taken together, these data suggest that the insecticides bind to Pgp with high affinity and effectively block drug transport. Inhibition of Pgp by pesticides may compromise its ability to clear xenobiotics from the body, leading to a higher risk of toxicity.

Preparation of Sialic Acid-Imprinted Fluorescent Conjugated Nanoparticles and Their Application for Targeted Cancer Cell Imaging.

Fluorescent conjugated polymer nanoparticles have attracted great interest for applications in biological imaging owing to their excellent optical properties and low cytotoxicity; however, a lack of effective targeting limits their use. In this work, we design and synthesize a fluorescent conjugated polymer modified with a phenylboronic acid group, which can covalently bind with cis-diol-containing compounds, such as sialic acid (SA), by forming a cyclic ester. However, the obtained conjugated polymer nanoparticles failed to discriminate between cancer cells, with or without SA overexpressed surfaces (such as DU 145 and HeLa cells, respectively). To address this problem, we introduced SA template molecules into the polymer nanoparticles during the reprecipitation process and then removed the template by adjusting the solution pH. The SA-imprinted nanoparticles showed a uniform size around 30 nm and enhanced fluorescence intensity compared with unmodified polymer nanoparticles. The SA-imprinted nanoparticles exhibited selective staining for DU 145 cancer cells and did not enter HeLa cells even after long incubation times. Thus, we present a facile method to prepare fluorescent nanoparticles for applications in targeted cancer cell imaging.

The role of the ATM/Chk/P53 pathway in mediating DNA damage in hand-foot syndrome induced by PLD.

Pegylated liposomal doxorubicin (PLD) has been approved to treat patients with various types of cancers because it rarely caused side effects, such as cardiotoxicity, in comparison to doxorubicin, but it frequently results in hand-foot syndrome (HFS). This may affect the quality of life and require a reduction in the PLD dose. The pathophysiology of HFS was not well understood. This study was aimed at exploring the mechanism of HFS induced by PLD. We compared the effects of different doses of PLD on the proliferation inhibition and apoptosis in vitro in HaCaT cells and analyzed the skin changes and skin cell DNA damage in vivo using a zebrafish model. The results suggested that very low doses of PLD show a proliferation inhibition (cell cycle arrest at G2/M phase) and an apoptosis phenotype characterized by the ATM/Chk/P53 pathway that mediates DNA damage in vitro in HaCaT cells. In addition, PLD enhanced zebrafish skin pigmentation from the head to the trunk and induced DNA damage (phospho-H2AX staining) and cell death in the skin of zebrafish. The results of the present study suggested potential applications to provide a better understanding of the apoptosis of PLD-treated skin cells and described a simple methodology for detecting a PLD-induced DNA damage response in zebrafish, which may be helpful in preventing and treating HFS.

Nanoparticles made of π-conjugated compounds targeted for chemical and biological applications.

Semiconducting organic nanoparticles have recently attracted increasing attention in the chemical and biomedical fields. Such nanoparticles are mainly composed of π-conjugated compounds. They possess the properties of easy synthesis, facile tuning, less toxicity and more biocompatibility relative to the existing inorganic nanoparticles. In addition, they show advantages such as brighter fluorescence, higher photostability and higher biocompatibility, compared with classical fluorescent organic dyes. In this review, we summarize the latest advances in the development of organic nanoparticles made of π-conjugated compounds, including preparation methods, material design, nanoparticle fabrication and surface functionalization for chemical and biological applications. Especially, we focus on the applications of semiconducting organic nanoparticles in chemical and biological sensing by monitoring the fluorescence signal, as nanocarriers for drug/gene delivery, in photothermal and photodynamic therapy, and in photoacoustic imaging. Finally, the challenges and perspectives for the future development of organic nanoparticles based on π-conjugated compounds are also discussed.

Determination of main components and anaerobic rumen digestibility of aquatic plants in vitro using near-infrared-reflectance spectroscopy.

A near-infrared-reflectance (NIR) spectroscopy-based method is established to determine the main components of aquatic plants as well as their anaerobic rumen biodegradability. The developed method is more rapid and accurate compared to the conventional chemical analysis and biodegradability tests. Moisture, volatile solid, Klason lignin and ash in entire aquatic plants could be accurately predicted using this method with coefficient of determination (r(2)) values of 0.952, 0.916, 0.939 and 0.950, respectively. In addition, the anaerobic rumen biodegradability of aquatic plants, represented as biogas and methane yields, could also be predicted well. The algorithm of continuous wavelet transform for the NIR spectral data pretreatment is able to greatly enhance the robustness and predictive ability of the NIR spectral analysis. These results indicate that NIR spectroscopy could be used to predict the main components of aquatic plants and their anaerobic biodegradability.