Comparison and application of two microextractions based on syringe membrane filter.

Two proposed syringe membrane filter solid phase microextraction and syringe membrane filter liquid/solid phase microextraction, coupled separately with high performance liquid chromatography, were developed for simultaneous enrichment and determination of the trace level of flavonoids in traditional Chinese medicine. In syringe membrane filter solid phase microextraction, the membrane of syringe membrane filter was served as a solid adsorption film to adsorb target analytes. And in syringe membrane filter liquid/solid phase microextraction, the membrane of syringe membrane filter was used as not only an adsorption phase, but also as a holder of extraction solvent to realize liquid-solid synergistic extraction. The simple operation, rapid extraction, and little or no organic solvent consumption make the two approaches very interesting. To evaluate the two proposed approaches, the crucial parameters affecting the enrichment factors of target analytes were investigated and optimized, and the two microextractions were intercompared. Moreover, their microextraction mechanisms were analyzed and described. Under the optimized conditions, both the new approaches achieved good linearities, accuracies, precisions, and low limits of detection, and the two methods were successfully applied for concentration of the flavonoids in traditional Chinese medicines.

Salt-assisted dispersive liquid-liquid microextraction for enhancing the concentration of matrine alkaloids in traditional Chinese medicine and its preparations.

A fast, simple, and efficient salt-assisted dispersive liquid-liquid microextraction coupled with high-performance liquid chromatography was developed and introduced for the simultaneous enrichment, extraction, and determination of the trace levels of matrine alkaloids (sophoridine, matrine, and sophocarpine) in Sophorae Flavescentis Radix and Composite Kushen injection. Compared with conventional dispersive liquid-liquid microextraction, the proposed method, with added salt but without dispersant and centrifuging, makes the operation simpler, greener, and leads to a higher enrichment factor. The crucial parameters affecting the enrichment factors of target analytes, such as type and volume of extraction solvent, pH of sample phase, salt concentration, volume of sample phase, and extraction time, were investigated and optimized, meanwhile, the extraction mechanism of the method was analyzed and described. Under the optimized conditions, the enrichment factors of the three matrine alkaloids were 150, 178, and 227, respectively. Good linearities (r2  ≥ 0.9992) for all analytes, low limits of detection (less than 0.08 ng/mL), satisfactory precisions (2.1-12.3%), and accuracies (recoveries, 99.3-103.9%) were achieved. The experimental results showed that the approach is a simple, fast, green, eco-friendly, and sensitive method and can be used for the preconcentration and determination of matrine alkaloids in traditional Chinese medicines and their preparations.

Epigallocatechin gallate promotes the development of mouse 2-cell embryos in vitro by regulating mitochondrial activity and expression of genes related to p53 signalling pathway.

Preliminary studies have found that the epigallocatechin gallate (EGCG) at proper concentration could promote development of pre-implantation mouse embryos in vitro. However, the underlying mechanisms have not been well understood. In this study, we collected 1-cell embryos from Kunming (KM) mice, cultured them in M16 medium or M16 medium supplemented with 10 µg/mL EGCG and investigated the effects of EGCG on mitochondrial activity and reactive oxygen species (ROS) level of 2-cell embryos. Furthermore, we explored expression differences of genes related to p53 signalling pathway in 2-cell embryos using a PCR array. The results showed that ROS level and mitochondrial membrane potential were significantly lower in embryos cultured in the EGCG group than in the M16 group (p < 0.05), while the adenosine triphosphate content was slightly lower than in the M16 group (p > 0.05). PCR array test results showed that 18 genes were differentially expressed, among which eight genes involving cell growth, cell cycle regulation and mRNA transcription were up-regulated and 10 genes involving apoptosis, cell cycle arrest and DNA repair were down-regulated in the EGCG groups. It is concluded that EGCG could promote the development of 1-cell embryos in vitro possibly due to its ability to scavenge ROS and regulate mitochondrial activity. In addition, EGCG could influence expression of genes related to p53 signalling pathway in 2-cell embryos and promote cell cycle progression.

Effects of Rehmannia glutinosa oligosaccharide on human adipose-derived mesenchymal stem cells in vitro.

AIMS: Adipose-derived mesenchymal stem cells (ADMSCs) are considered as a good cell source for regenerative medicine with their self-renew capacity, multilineage differentiation and immunomodulatory potency. Based on this background, the aim of this study was to evaluate the influence of Rehmannia glutinosa oligosaccharide (RGO), a traditional Chinese medicine, on human ADMSCs' proliferation, H(2)O(2)-induced apoptosis, and secretion of Vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) in vitro. MAIN METHODS: Human ADMSCs were isolated and cultured in vitro. Then flow cytometry was carried out to characterize the cells, and MTT assay was performed to detect the proliferation. H(2)O(2)-induced apoptosis was evaluated by flow cytometry. VEGF and HGF production were detected by ELISA kits. KEY FINDINGS: Human ADMSCs were positive for CD90 and CD29, but negative for CD31, CD34 and CD45. The results also indicate that RGO can promote the proliferation and alleviate H(2)O(2)-induced apoptosis of human ADMSCs. The mechanism of RGO's protective effect may involve the up-regulation of VEGF and HGF. SIGNIFICANCE: The present study indicates that RGO may increase the viability and proliferative capacity and alleviate H(2)O(2)-induced apoptosis of human ADMSCs via the paracrine release of VEGF and HGF. These results indicate that RGO application will enhance stem cell viability and improve their effects in cell therapy.