摘要：
The green tea polyphenol epigallocatechin-3-gallate (EGCG) is widely consumed as a dietary supplement. Its potential properties include slowing aging and extending lifespan, although how exactly this is achieved remains unclear. Here, we report that EGCG promoted healthy lifespan in Caenorhabditis elegans when administered throughout or only at early-to-mid adulthood. Specifically, EGCG extended lifespan in an inverted U-shaped dose-response manner. The life-extending mechanism was stimulated by EGCG-induced production of reactive oxygen species (ROS). Additionally, EGCG triggered mitochondrial biogenesis to restore mitochondrial function. The EGCG-induced increase in lifespan depends on known energy sensors such as AMPK/AAK-2, as well as SIRT1/SIR-2.1 and FOXO/DAF-16. Interestingly, aging decreased the response to EGCG and progressively neutralized its beneficial effects on longevity. Collectively, our findings link EGCG to the process of mitohormesis and suggest an inducible, AMPK/SIRT1/FOXO-dependent redox signaling module that could be invoked in different contexts to extend healthy lifespan. Its effectiveness is higher in younger adults and declines with age.
摘要：
Fuzhuan brick tea (FBT) possesses various health-promoting functions. However, the available information regarding biological activity of polysaccharides from FBT (FBTPS) is still limited. In this work, the chemical property, cytotoxicity and antioxidant activity in vitro and in vivo of FBTPS were evaluated. It was found that FBTPSs were typical acidic heteropolysaccharides mainly composed of Man, Rha, GalA, Glc, Gal and Ara with little molar content of Rib and GIcA. FBTPS showed little toxicity to human hepatic epithelial (L-02) cell. FBTPS exhibited antioxidant activities, including limited scavenging activity on DPPH free radicals (ranged from 543 +/- 1.9 to 67.8 +/- 2.5%), noticeable scavenging activity on superoxide radicals (over 85%), superior scavenging activity on ABTS radicals (near 100%), and protective effect on H2O2-induced oxidative injury in rat pheochromocytoma line 12 (PC12) cell. Moreover, FBTPS showed significant amelioration of high-fat diet-induced oxidative injury in mice. The results suggest that FBTPS, as natural safe antioxidants, may have potential application in functional foods. (C) 2018 Elsevier B.V. All rights reserved.
摘要：
IntroductionMedicinal plants are gaining increasing attention worldwide due to their empirical therapeutic efficacy and being a huge natural compound pool for new drug discovery and development. The efficacy, safety and quality of medicinal plants are the main concerns, which are highly dependent on the comprehensive analysis of chemical components in the medicinal plants. With the advances in mass spectrometry (MS) techniques, comprehensive analysis and fast identification of complex phytochemical components have become feasible, and may meet the needs, for the analysis of medicinal plants. ObjectiveOur aim is to provide an overview on the latest developments in MS and its hyphenated technique and their applications for the comprehensive analysis of medicinal plants. MethodologyApplication of various MS and its hyphenated techniques for the analysis of medicinal plants, including but not limited to one-dimensional chromatography, multiple-dimensional chromatography coupled to MS, ambient ionisation MS, and mass spectral database, have been reviewed and compared in this work. ResultsRecent advancs in MS and its hyphenated techniques have made MS one of the most powerful tools for the analysis of complex extracts from medicinal plants due to its excellent separation and identification ability, high sensitivity and resolution, and wide detection dynamic range. ConclusionTo achieve high-throughput or multi-dimensional analysis of medicinal plants, the state-of-the-art MS and its hyphenated techniques have played, and will continue to play a great role in being the major platform for their further research in order to obtain insight into both their empirical therapeutic efficacy and quality control. The efficacy, safety and quality of medicinal plants are highly dependent on the comprehensive analysis of their chemical components; The latest developments in MS and its hyphenated technique and their applications for the comprehensive analysis of medicinal plants have been reviewed; To achieve high-throughput or multi-dimensional analysis of medicinal plants, MS and its hyphenated techniques have played, and will continue to play a great role.
关键词：
anion-exchange resin;Artemisia annua L.;artemisinin production waste;dihydroartemisinic acid;silica-gel chromatography
摘要：
In order to make full use of artemisinin production waste and thus to reduce the production cost of artemisinin, we developed an efficient and scalable method to isolate high-purity dihydroartemisinic acid from artemisinin production waste by combining anion-exchange resin with silica-gel column chromatography. The adsorption and desorption characteristics of dihydroartemisinic acid on 10 types of anion-exchange resin were investigated, and the results showed that the 717 anion-exchange resin exhibited the highest capacity of adsorption and desorption to dihydroartemisinic acid. Adsorption isotherms were established for the 717 anion-exchange resin and they fitted well with both Langmuir and Freundlich model. Dynamic adsorption and desorption properties of 717 anion-exchange resin were characterized to optimize the chromatographic conditions. Subsequently, the silica-gel column chromatography was performed and dihydroartemisinic acid with a purity of up to 98% (w/w) was obtained. Finally, the scale-up experiments validated the preparative separation of high-purity dihydroartemisinic acid from industrial waste developed in the present work. This work presented for the first time an isolation of dihydroartemisinic acid with a purity of 98% from Artemisia annua (A. annua) by-product, which adds more value to this crop and has the potential to lower the prices of anti-malarial drugs.
作者机构：
[Liu, Zhonghua; Cai, Shuxian] Hunan Agr Univ, Natl Res Ctr Engn Technol Utilizat Bot Funct Ingr, Changsha 410128, Hunan, Peoples R China.;[Liu, Xingfang] Chinese Acad Sci, Key Lab Semicond Mat Sci, Inst Semicond, Beijing 100083, Peoples R China.;[Huang, Jianan; Cai, Shuxian] Hunan Agr Univ, Key Lab, Minist Educ TEA Sci, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Liu, Zhonghua] H;[Liu, Xingfang] C;Hunan Agr Univ, Natl Res Ctr Engn Technol Utilizat Bot Funct Ingr, Changsha 410128, Hunan, Peoples R China.;Chinese Acad Sci, Key Lab Semicond Mat Sci, Inst Semicond, Beijing 100083, Peoples R China.
摘要：
Chemical vapour deposited graphene on Cu foil should be transferred to target dielectric substrate before being used in various applications. This route often involves preparation of a supporting material on graphene before the transfer process and removal of the material after graphene is transferred to a foreign substrate. Herein, we demonstrate a simple process combining graphene transfer and subsequent graphene-based sensor preparation in one route. By applying a thin flexible polyethylene (PE) film onto graphene and subsequently chemical etching Cu foil, this process enables the high-quality transfer of graphene on PE film. A flexible strain sensor prepared from the as-transferred graphene/PE film shows good detection sensitivity. Therefore, this process could greatly reduce the cost of transfer and device fabrication for mass production.
