Effects of squalene on expression of LDLR in HepG2 cells and its mechanism北大核心CSCD

Aim To investigate the effect of squalene on LDLR expression in HepG2 cells and its mechanism of down-regulated cholesterol. Methods The proliferation of HepG2 cells exposed to squalene at different concentrations was measured by MTT assay. The effect of squalene on the expression of LDLR in HepG2 cells was measured by flow cytometry and fluorescence mi-croscopy. The effect of different concentrations of squalene on the interaction between SCAP and Insig2, two key protein molecules of SREBP pathway, was assayed by FRET technology. Results MTT results showed that squalene had inhibitory effect on the proliferation of HepG2 cells in a dose-dependent manner. Flow cytometry and fluorescence microscopy results showed that squalene enhanced LDLR expression in HepG2 cells compared with the control group. The results of FRET technology revealed that compared with model control group, the YFP fluorescence value in Squalene group dramatically declined, and the YFP fluorescence value of each drug group decreased with the range of 5-25 |xmol L1 squalene concentration. Conclusions Squalene may promote the expression of LDLR in HepG2 cells through inhibiting the interaction between SCAP and Insig2 proteins in SREBP pathway, which may confirm that squalene is a potential novel drug for the down-regulation of cholesterol level. © 2018 Publication Centre of Anhui Medical University. All rights reserved.     

苍耳子药材的HPLC特征图谱研究

摘 要 目的：建立苍耳子药材的HPLC特征图谱,为评价不同产地苍耳子的质量提供参考。方法: 采用Alltima C18（250 mm×4.6 mm,5 μm）,流动相乙腈 0.1%磷酸溶液梯度洗脱,流速：0.8 ml·min^-1,检测波长：278 nm,柱温：25 ℃,对来自河南、吉林、安徽等地共47批苍耳子样品运用“中药指纹图谱相似度评价系统”进行分析。 结果:以绿原酸为参照峰,初步构建了由5个特征峰组成的苍耳子HPLC 特征图谱。结论:该方法简便、可靠,为苍耳子药材的质量控制提供了有效的评价方法。     

A new strategy for choosing “Q-markers” via network pharmacology,application to the quality control of a Chinese medical preparation

Due to its chemical complexity, proper quality control for a Chinese medical preparation (CMP) has been a great challenge. Choosing the appropriate quality markers (Q-markers) for quality control of CMP is an important work. Best of all, the chosen Q-markers are the main chemical compounds from the herbals as well as the active constituents of this CMP. Only in this way the established quality control system can really achieve the purpose of controlling the quality of CMP and ensuring the safely and effectively use of CMP. To achieve the purpose, network pharmacology combined with the contents of chemical compounds in the CMP has been used in this research. We took an anti-arrhythmic CMP, Shenxian-Shengmai oral liquid (SSOL), as an example. Firstly, UPLC-QTOF-MS/MS method was used to analyze the main components of SSOL. A total of 64 compounds were unambiguously or tentatively identified and 32 of them were further validated by reference compounds. Secondly, the network was constructed based on the identified compounds to predict the effective compounds related to cardiac arrhythmias. Based on the existing database and the operation method of topology, a method of double network analysis (DNAA) was proposed, from which 10 important targets in the pathway of arrhythmia were screened out, and 26 compounds had good antiarrhythmic activity. Based on the prediction results of network pharmacology along with the contents of the compounds in this CMP, ten representative compounds were chosen as the Q-markers for the quality control of SSOL. We find that five of these ten compounds, including danshensu, rosmarinic acid, salvianolic acid A, epimedin A and icariin, have antiarrhythmic activity. Then, the UPLC-DAD method was established as the control method for SSOL.     

Enzymatic glycosylation of oleanane-type triterpenoids

Abstract

Glycosylation is an effective approach to improve the druggability of natural products by increasing their water solubility. In this work, we report the glycosylation of oleanane-type triterpenoids by a recombinant microbial glycosyltransferase YjiC1. A preliminary screening test indicated YjiC1 exhibited robust capabilities for O-glycosylation of triterpenoids, based on LC/MS analysis. Among the products, two new compounds (2a and 3a), together with a known one (1a), were isolated and characterized. These products exhibited improved water solubility, and 3a showed moderate anti-HIV activities at 100 μM. This reaction provides a facile and efficient approach to synthesize the glucosides of triterpenoids.     

Two new saponins from the leaves of Panax notoginseng

Two new saponins, notoginsenosides Ng1 (1) and Ng2 (2), together with seven known compounds (3–9), were isolated from the leaves of Panax notoginseng. Their structures were elucidated by UV, IR, HRESIMS, and NMR experiments. Compounds 6 and 7 showed moderate cytotoxic activities against HCT-116, with IC₅₀ values of 4.98 and 0.64 μmol/L, respectively.     

Homoisoflavanones with estrogenic activity from the rhizomes of Polygonatum sibiricum

A new homoisoflavanone, (3R)-5-hydroxy-7-methoxyl-3-(2′-hydroxy-4′- methoxybenzyl)-chroman-4-one (1), together with six known analogs, were isolated from the rhizomes of Polygonatum sibiricum. Their structures were elucidated on the basis of extensive spectroscopic analysis. All compounds were tested for their estrogenic activity using the MCF-7 estrogenresponsive human breast cancer cell lines. At a dose of 0.1 μmol/L, compounds 1–7 exhibited significant proliferative effects on MCF-7 cells compared with E₂. The molecular docking study results indicated that the activity of compounds 3, 5, 6, and 7 may be the binding with ERR.     

Using previous trial results to inform hypothesis testing of new interventions

Results of industry-sponsored Phase III trials registered at clinicaltrials.gov include a rich amount of information on the efficacy of medical interventions. We propose that these results can be used to inform hypothesis testing of a new intervention through the Bayes principle. The posterior probability of positive efficacy offers an accessible interpretation of the uncertainty of efficacy and a convenient metric for global false-positive control.     

On evaluation of consistency in multi-regional clinical trials

In recent years, multi-regional clinical trials (MRCT) that conduct clinical trials simultaneously in Asian Pacific region, Europe, and the United States have become very popular for global pharmaceutical development. The main purpose of multi-regional clinical trials is to shorten the time for pharmaceutical development and regulatory submission, and approval around the world. In practice, however, clinical results observed from some regions (sub-population) may not be consistent with the results from other regions and/or all regions combined (entire population). The inconsistency observed may be due to ethnic differences in different regions, differences in medical practice, time points of assessment, or by random chance due to small sample size for the region. Some regional regulatory agencies require consistency evaluation between local country results and overall results. However, the challenge is there is no detailed guidance on the definition of ‘consistency’ and methodology to evaluate it. Therefore, the questions are: how to evaluate consistency and what statistical methods are appropriate to be used for consistency evaluation? In this article, several statistical tests for consistency (similarity) between clinical results observed from a specific sub-population and the entire population are proposed. These methods are compared through extensive simulation. As most published articles discussed consistency evaluation for superiority situations, we have discussed consistency evaluation for non-inferiority situation in this article through a simulated example concerning consistency in some countries. Recommendations of the statistical methods to be used for consistency evaluation are given. Other aspects that should be considered for consistency evaluation are also provided.