[Effect of Total Ravonoids of Herba Epimedium on BMP-2/RunX2/OSX Signaling Pathway during Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells].

OBJECTIVE: To explore the effect of total flavonoids of Herba Epimedium (FHE) on BMP-2/RunX2/OSX signaling pathway in promoting osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). METHODS: Passage 3 BMSCs were randomly divided into the control group, the experimental group, and the inhibitor group. BMSCs in the control group were cultured in 0.2% dimethyl sulfoxide + Osteogenuxic Supplement (OS) fluid + DMEM/F12 culture media. BMSCs in the experimental group were intervened by 20 microg/mL FHE. BMSCs in the inhibitor group were intervened by 20 microg/mL FHE and 1 microg/mL NOGGIN recombinant protein. At day 9 alkaline phosphatase (ALP) activity was measured. Calcium nodules were stained by alizarin red staining and the density was observed. The transcription expression of osteogenic differentiation-related proteins (type I collagen, osteocalcin, and osteopontin) and related factors of BMP-2/RunX2/OSX signaling pathway was assayed by RT-PCR. RESULTS: Compared with the control group, ALP activities were enhanced and the density of calcium nodules significantly increased; type I collagen, osteocalcin, and osteopontin expression levels were increased in the experimental group. The expression of osteogenesis-related transcription factor was also increased in the experimental group. Noggin recombinant protein inhibited FHE promoting BMSCs osteogenesis in the inhibitor group. Compared with the experimental group, ALP activity decreased (P < 0.05), the density of calcium nodules was lowered, expression levels of type I collagen, osteocalcin, osteopontin significantly decreased (P < 0.05) in the inhibitor group. CONCLUSION: 20 microg/mL FHE promoted osteogenic differentiation process of BMSCs by BMP-2/RunX2/OSX signaling pathway.

[Mechanism of chlorogenic acid on apoptosis of rat nucleus pulposus cells induced by oxidative stress].

OBJECTIVE: To investigate the mechanism of chlorogenic acid (CGA) on H2O2-induced apoptosis in the rat nucleus pulposus cells (NPCs). METHODS: NPCs were isolated from SD rats and cultured in vitro. Cultured cells (P3) were randomly divided into normal control group, H2O2 group, CGA + H2O2 group, CGA group and LY294002 pretreatment group. The apoptosis and ROS production of rNPCs was detected by flow cytometry. The expressions of p-Akt, BCL-2 and Akt were analyzed by Western blot. RESULTS: Compared with normal control group, in the H2O2 group, the production of ROS and the apoptosis rate significantly increased in rNPCs; CGA treatment inhibited ROS production and cell apoptosis, while increased the expression of p-Akt and BCL-2; LY294002, a PI3Kinse inhibitor, not only decreased the expression of p-Akt and BCL-2, but also obviously increased ROS production and cell apoptosis. CONCLUSION: Chlorogenic acid can protect NPCs against apoptosis by oxidative stress through decreasing reactive oxygen species production and increasing anti-apoptotic protein BCL-2 expression in NPCs by activation of PI3K-Akt signaling pathways.

(5Z)-4-Amino-2-(4-hydroxyphenyl)-1H-imidazol-5(2H)-one oxime 3-oxide.

The title molecule, C(9)H(10)N(4)O(3), consists of benzene and imidazole rings which are almost perpendicular to each other. A hydroxyimino group is directly linked to the imidazole ring with a double C=N bond, which is the first example in this type of compound. The double bond may be a good location for the initiation of various reactions with a wide range of potential applications. In the crystal structure, there are pi-pi interactions between molecules related by a centre of symmetry, with the imidazole and benzene rings almost completely overlapped. The molecules are hydrogen bonded in each direction and form a three-dimensional hydrogen-bond network.

[Determination of citalopram in human plasma with LC-MS/MS method and its bioequivalent evaluation].

A sensitive and selective LC-MS/MS method for determination of citalopram in human plasma was established to study the bioequivalence of different formulations containing citalopram. The samples were simply pretreated by protein precipitation using acetonitrile, and then analyzed on a Zorbax Extend C8 column. The mobile phase consisted of acetonitrile-water-formic acid (60:40:0.2), at a flow-rate of 0.5 mL x min(-1). A Thermo Finnigan TSQ Quantum Ultra tandem mass spectrometer equipped with electrospray ionization source was used as detector and was operated in the positive ion mode. Selected reaction monitoring using the precursor to product ion combinations of m/z 325 --> m/z 109 and m/z 265 --> m/z 167 was performed to quantify citalopram and the internal standard, respectively. The pharmacokinetic parameters of citalopram in different formulations were calculated by non-compartment model. The linear calibration curves were obtained in the concentration range of 0.10-100 microg x L(-1). The lower limit of quantification was 0.10 microg x L(-1). The intra- and inter-day relative standard deviation (RSD) over the entire concentration range was less than 5.2%. Accuracy determined at three concentrations (0.25, 8.00 and 90.0 microg x L(-1) for citalopram) ranged from -4.7% to 1.3%. Each plasma sample was chromatographed within 3.0 min. The method was successfully used in bioequivalence study of citalopram in human plasma after oral administration of 20 mg citalopram. Calculated with AUC(0-120 h), the bioavailability of two formulations was (102.1 +/- 10.9)%. The method is rapid, selective, robust and is proved to be suitable for bioequivalence evaluation of different formulations containing citalopram.

Rapamycin Inhibits Oxidized Low Density Lipoprotein Uptake in Human Umbilical Vein Endothelial Cells via mTOR/NF-κB/LOX-1 Pathway.

BACKGROUND: Lectin-like oxidized low-density lipoprotein-1 (LOX-1) is the major receptor for oxidized low density lipoprotein (ox-LDL) uptake in human umbilical vein endothelial cells (HUVECs). Previously, we found that rapamycin inhibited ox-LDL accumulation in HUVECs, and this effect was related to its role in increasing the activity of autophagy-lysosome pathway. In this study, we determined whether rapamycin could also reduce ox-LDL uptake in HUVECs and investigated the underlying signaling mechanisms. RESULTS: Flow cytometry and live cell imaging showed that rapamycin reduced Dil-ox-LDL accumulation in HUVECs. Furthermore, rapamycin reduced the ox-LDL-induced increase in LOX-1 mRNA and protein levels. Western blotting showed that rapamycin inhibited mechanistic target of rapamycin (mTOR), p70s6k and IκBα phosphorylation triggered by ox-LDL. Flow cytometry implied that mTOR, NF-κB knockdown and NF-κB inhibitors significantly reduced Dil-ox-LDL uptake. Moreover, immunofluorescent staining showed that rapamycin reduced the accumulation of p65 in the nucleus after ox-LDL treatment for 30 h. mTOR knockdown decreased LOX-1 protein production and IκBα phosphorylation induced by ox-LDL. NF-κB knockdown and NF-κB inhibitors reduced LOX-1 protein production, but did not inhibit mTOR phosphorylation stimulated by ox-LDL. CONCLUSIONS: These findings demonstrate that rapamycin reduce mTOR phosphorylation and subsequently inhibit NF-κB activation and suppresses LOX-1, resulting in a reduction in ox-LDL uptake in HUVECs.