ABSTRACT
The biological potency assay and chemical fingerprint chromatogram were applied to quality evaluation of rhubarb. Using the biological potency as indicators, we evaluated the differences in quality of multiple batches of rhubarbs and related products. Using the platelet aggregation analyzer, we determined platelet aggregation rate in the different rhubarbs preparations, and calculated the biological potency based on the simplified probit principle. UPLC was adopted to establish the fingerprint spectra for rhubarbs. The spectral efficiency correlation analysis between chromatograms and biological potencies were conducted using the double variables of SPSS 22.0 software. We used three chemical composition to verify the potency. The biological potency results suggest that Rheum palmatum has a more potent activity than Rheum tanguticum, and wine-treated rhubarb had a higher potentcy than charred. We identified 10 elements in the Fingerprint Spectrum. The relevant elements including rhein-8-O-β-D-glucoside, emodin-8-O-β-D-glucoside and rhein have the strongest activity in the inhibition of platelet aggregation. In conclusion, this study provides a analytical method for rhubarb biological potency based on determination of the maximum antagonism rate model. The rhein may be the effective substance. It may serve as a reference in the quality control of wine processed rhubarb products.
ABSTRACT
To explore the active substance of antiplatelet aggregation of Polygoni Multiflori Radix by using chemical fingerprints and antiplatelet aggregation bioactivity test for spectrum-effect correlation analysis. The Polygoni Multiflori Radix was tested by antiplatelet aggregation in vitro, and the results showed that 50% aqueous ethanol extract of Polygoni Multiflori Radix had more potent antiplatelet aggregation effect than 10% or 90% aqueous ethanol extract, and ultrasonic extraction was superior to refluxing extraction in the aspect of antiplatelet aggregation. The antiplatelet aggregation bioactivity of the different Polygoni Multiflori Radix extracts was evaluated and the results showed that the inhibition rate was 32.03%-74.56%. Spectrum-effect correlation analysis indicated that trans-stilbene glucoside, cis-stilbene glucoside and catechinic acid had higher correlation coefficient and they were 0.963 (P<0.01), 0.902 (P<0.01) and 0.656 (P<0.05) respectively; furthermore, all of the above three compounds demonstrated significant antiplatelet aggregation bioactivities. Considering their content difference in Polygoni Multiflori Radix, we calculated the relative active contributions, and the results suggested that trans-stilbene glucoside was the main active substance of Polygoni Multiflori Radix in the aspect of antiplatelet aggregation in vitro.
ABSTRACT
<p><b>BACKGROUND</b>The development of regenerative therapies using derivatives of embryonic stem (ES) cells would be facilitated by a non-invasive method to monitor transplanted cells in vivo, for example, magnetic resonance imaging of cells labeled with superparamagnetic iron oxide (SPIO) nanoparticles. Although ES cells have been labeled with SPIO particles, the potential adverse effects of the label have not been fully examined. The objective of this study was to determine whether SPIO labeling affects murine ES cell viability, proliferation, or ability to differentiate into functional endothelial cells (ECs).</p><p><b>METHODS</b>Cross-linked iron oxide (CLIO, an SPIO) was conjugated with human immunodeficiency virus transactivator of transcription (HIV-Tat) peptides, and murine ES cells were labeled with either CLIO-Tat, CLIO, or HIV-Tat. After labeling, ES cells were cultured for 4 days and Flk-1(+) ES cells identified and sorted by immunocytochemistry and fluorescence activated cell sorting (FACS). Flk-1(+) cells were replated on fibronectin-coated dishes, and ECs were obtained by culturing these for 4 weeks in endothelial cell growth medium supplemented with vascular endothelial growth factor (VEGF). ES cell viability was determined using trypan blue exclusion, and the proportion of SPIO(+) cells was evaluated using Prussian blue staining and transmission electron microscopy. After differentiation, the behavior and phenotype of ECs were analyzed by reverse transcription-polymerase chain reaction, flow cytometry, immunocytochemistry, DiI-labeled acetylated low-density lipoprotein (AcLDL) uptake, and Matrigel tube formation assay.</p><p><b>RESULTS</b>CLIO-Tat was a highly effective label for ES cells, with > 96% of cells incorporating the particles, and it did not alter the viability of the labeled cells. ECs derived from CLIO-Tat(+) ES cells were very similar to murine aortic ECs in their morphology, expression of endothelial cell markers, ability to form vascular-like channels, and scavenging of AcLDL from the culture medium.</p><p><b>CONCLUSIONS</b>CLIO-Tat is a highly effective label for ES cells and does not adversely affect cell viability, differentiation, or behavior. CLIO-Tat could be a useful marker for the non-invasive monitoring of transplanted stem cells.</p>