The Changes in Bioactive Compounds and Antioxidant Activity of Chia (Salvia hispanica L.) Herb under Storage and Different Drying Conditions: A Comparison with Other Species of Sage

Studies on herb chia (Salvia hispanica L.) are very limited. Therefore, the aim of this study was to assess how different drying methods and periods of storage affect the bioactive properties of the herb Salvia hispanica and to compare it with other species of sage (Salvia officinalis L. and Salvia sclarea L.). In fresh herbs, directly after drying (freeze-drying, natural drying, and drying at 30, 40, and 50 °C), and after storage (3, 6, and 12 months), the following analyses were performed: content of total carotenoids and total polyphenols, polyphenol profile (including 25 compounds), and antioxidant activity. Additionally, the basic chemical compositions of the herbs were analyzed. To the best of our knowledge, the content of total carotenoids and the quantitative polyphenol profile in Salvia hispanica and Salvia sclarea were evaluated for the first time. The obtained results showed that the barely investigated herb Salvia hispanica is rich in polyphenolic compounds and shows high antioxidant activity. In all the tested species, rosmarinic acid was the most abundant polyphenolic compound. The use of different drying methods allowed us to determine that freeze-drying was the most effective for preserving polyphenols and carotenoids. Long-term storage up to 12 months resulted in a gradual reduction in antioxidant activity and in the content of polyphenols and carotenoids.     

Unravelling the Anticancer Mechanisms of Traditional Herbal Medicines with Metabolomics

Metabolite profiling of cancer cells presents many opportunities for anticancer drug discovery. The Chinese, Indian, and African flora, in particular, offers a diverse source of anticancer therapeutics as documented in traditional folklores. In-depth scientific information relating to mechanisms of action, quality control, and safety profile will promote their extensive usage in cancer therapy. Metabolomics may be a more holistic strategy to gain valuable insights into the anticancer mechanisms of action of plants but this has remained largely unexplored. This review, therefore, presents the available metabolomics studies on the anticancer effects of herbal medicines commonly used in Africa and Asia. In addition, we present some scientifically understudied ‘candidate plants’ for cancer metabolomics studies and highlight the relevance of metabolomics in addressing other challenges facing the drug development of anticancer herbs. Finally, we discussed the challenges of using metabolomics to uncover the underlying mechanisms of potential anticancer herbs and the progress made in this regard.     

高效液相色谱法测定大黄酸的含量

建立了测定大黄酸含量的高效液相色谱方法。分析柱为Waters symmetry C18色谱柱(150 mm×4.6 mm,5μm),流动相为甲醇-水-冰乙酸(70∶30∶2,体积比),流速0.8 mL.min-1,检测波长为254 nm,回收率为99.4%~100.2%,用于原料(掌叶大黄)和产品(大黄酸)的质量控制,同一天对大黄酸标准溶液连续测定和每隔1 h进样一次测定(n=6)的相对标准偏差为0.6%~0.8%。经测定原料(掌叶大黄)中大黄酸的质量分数为0.58%,产品中大黄酸的质量分数为73.1%~90.4%。     

Momentum effect differs across stock performances: Chinese evidence

Prior empirical studies find positive and negative momentum effect across the global nations, but few focus on explaining the mixed results. In order to address this issue, we apply the quantile regression approach to analyze the momentum effect in the context of Chinese stock market in this paper. The evidence suggests that the momentum effect in Chinese stock is not stable across firms with different levels of performance. We find that negative momentum effect in the short and medium horizon （3 months and 9 months） increases with the quantile of stock returns. And the positive momentum effect is observed in the long horizon （12 months）, which also intensifies for the high performing stocks. According to our study, momentum effect needs to be examined on the basis of stock returns. OLS estimation, which gives an exclusive and biased result, provides misguiding intuitions for momentum effect across the global nations. Based on the empirical results of quantile regression, effective risk control strategies can also be inspired by adjusting the proportion of assets with past performances.     

Comparative pharmacokinetics study of five alkaloids in rat plasma and related compound–herb interactions mechanism after oral administration of Shuanghua Baihe tablets

Shuanghua Baihe tablet is a traditional Chinese patent medicine which showed special advantages in the treatment of recurrent aphthous stomatitis. Scientists have improved and implemented the LC-MS/MS method, which is specific and sensitive, for comparative pharmacokinetics study of five alkaloids, including palmatine, berberine, epiberberine, jatrorrhizine and coptisine in rat plasma after oral administration of Rhizoma Coptidis extract and Shuanghua Baihe tablets. The results showed that Shuanghua Baihe tablets could promote the absorption of these five alkaloids and improved their bioavailability compared with R. Coptidis extract. To further investigate the related mechanism, everted intestinal sac model in vitro was used to indicate that alteration of in vivo pharmacokinetics of five alkaloids could be attributed to, at least in part, the absorption changes by coadministration of other herbs. These discoveries served as a theoretical basis for clinical use of Shuanghua Baihe tables.     

平性药有效成分与药性相关性研究

本文精选了50味平性药及50味对照非平性药作为研究对象;从各味药的有效成分入手,利用其所含有的特定的骨架及官能团信息直观地进行了数字化表征;采用模式识别中的支持向量机方法进行了分类研究,挑选最优特征时,总正确率最高可以达到73%,表明了中药的有效成分与其药性之间确实存在一定的相关关系。并且通过对识别率的比较发现,平性药药性的不显著本质上可能是由于其本身所含有效成分更高的分子多样性。本文对探索平性药药性的物质基础具有一定的指导作用。     

基于网络的中医药信息系统的开发和研究

介绍了北京大学中医药网络信息系统的设计方向及实现步骤,对该系统的开发平台、体系结构以及实现系统的相关技术进行了具体的分析与论述.该系统包括中草药、中成药、中药有效成分、中药食疗以及中药方剂等五个专业的数据库和其它大量中医药相关信息,这些网络数据库和信息构成了完整的中医药网络信息系统.通过和其它药物设计方法的结合,该信息系统成为基于中医药药物设计和发现先导化合物的重要工具.     

基于分词的垃圾邮件过滤系统设计与分析

以字为单位处理中文邮件存在着很大困难,针对于此,笔者引进中文分词算法,设计并实现了基于分词的垃圾邮件过滤系统,并且阐述了与实现相关的3个关键算法:用于关键词匹配的多模式相似/精确匹配算法,用于中文邮件处理的中文分词算法,以及用于特征提取的N元特征提取算法.最后实验证明了该系统对中英文垃圾邮件过滤都有很高的性能.另外,文章第三部分还给出了基于分词的非垃圾邮件分类系统的设计与实现.