Antioxidant Activities and Phytochemical Study of Leaf Extracts from 18 Indigenous Tree Species in Taiwan

The objective of this study is to assess antioxidant activities of methanolic extracts from the leaves of 18 indigenous tree species in Taiwan. Results revealed that, among 18 species, Acer oliverianum exhibited the best free radical scavenging activities. The IC50 values were 5.8 and 11.8 μg/mL on DPPH radical and superoxide radical scavenging activities, respectively. In addition, A. oliverianum also exhibited the strongest ferrous ion chelating activity. Based on a bioactivity-guided isolation principle, the resulting methanolic crude extracts of A. oliverianum leaves were fractionated to yield soluble fractions of hexane, EtOAc, BuOH, and water. Of these, the EtOAc fraction had the best antioxidant activity. Furthermore, 8 specific phytochemicals were isolated and identified from the EtOAc fraction. Among them, 1,2,3,4,6-O-penta-galloyl-β-D-glucopyranose had the best free radical scavenging activity. These results demonstrate that methanolic extracts and their derived phytochemicals of A. oliverianum leaves have excellent antioxidant activities and thus they have great potential as sources for natural health products

大時代的文化研究 : 馬照跑，舞照跳? = Will horse racing and dancing go on in the Great Era of Cultural Studies?

研討會分為二部分。第一部分的主題是「大時代的文化研究：馬照跑，舞照跳？」，以MCSian的論文為引旨，透過對話去思考在當前處境如何尋找出路，由鄧芝珊主持，分別由廖可兒主講〈從聯合國氣候變化大會到黃背心運動–反思「環境 vs 發展與生計」的二元對立〉，馮羚主講〈從台灣電音三太子看傳統文化的傳承與挑戰〉，譚家浚主講〈賽馬作為統治殖民手段 - 由被統治者的接受與反抗所演變成的香港賽馬文化〉，並由李小良評論及與講者進行討論

Antioxidant Activities and Phytochemicals of Leaf Extracts from 10 Native Rhododendron

Rhododendron, one of the most famous ornamental plants in the world, is traditionally a medicinal plant. However, the potential bioactivities of native Rhododendron in Taiwan have not been completely studied. In this study, the results revealed that Rhododendron pseudochrysanthum exhibited the best antioxidant activities among 10 native Rhododendron species in Taiwan. Furthermore, based on a bioactivity-guided isolation principle, nine specific phytochemicals were isolated and identified as (2R,3S)-catechin (1), (2R,3R)-epicatechin (1′), (2R,3R)-dihydromyricetin 3-O-β-l-arabinopyranoside (2), (2S,3S)-taxifolin 3-O-β-l-arabinopyranoside (2′), (2R,3R)-taxifolin 3-O-β-l-arabinopyranoside (3), myricetin 3-O-β-d-glucopyranoside (3′), rutin (4), hyperoside (5), and quercitrin (6). Of these compounds, 2 and 3 were found to be major bioactive compounds, and their concentrations in the n-butanol (BuOH) fraction were determined to be 52.0 and 67.3 mg per gram, respectively. These results demonstrated that methanolic extracts of Rhododendron pseudochrysanthum leaves have excellent antioxidant activities and great potential as a source for natural health products

In vitro ruminal fermentation and cow-to-mouse fecal transplantations verify the inter-relationship of microbiome and metabolome biomarkers: potential to promote health in dairy cows

IntroductionThere are differences in the gut microbiome and metabolome when the host undergoes different physical or pathological conditions. However, the inter-relationship of microbiome and metabolome biomarkers to potentially promote the health of dairy cows needs to be studied. Further, the development of next-generation probiotics for dairy cattle health promotion has not been demonstrated.ObjectiveIn the present study, we identified the microbiome and metabolome biomarkers associated with healthy cows.MethodsWe analyzed the relationships of the ruminal microorganism profile and metabolites between healthy and mastitis lactating dairy cows. The roles of bacterial biomarker were further verified by in vitro fermentation and cow-to-mouse fecal microbiota transplantation (FMT).ResultsTwo species, Ruminococcus flavefaciens and Bifidobacterium longum subsp. longum, and six rumen metabolites were positively correlated with healthy cows by Spearman’s correlation analysis. Through in vitro ruminal fermentation, inoculating R. flavefaciens and B. longum subsp. longum showed the upregulation of the levels of putrescine, xanthurenic acid, and pyridoxal in the mastitis ruminal fluid, which confirmed the inter-relationships between these microbiota and metabolites associated with healthy cows. Further, we verified the role of R. flavefaciens and B. longum subsp. longum in promoting health by FMT. The administration of R. flavefaciens and B. longum subsp. longum reduced the death rate and recovered the bodyweight loss of germ-free mice caused by FMT mastitis feces.DiscussionWe provided evidence that the bacterial biomarkers alter downstream metabolites. This could indirectly indicate that the two bacterial biomarkers have the potential to be used as next-generation probiotics for dairy cattle, although it needs more evidence to support our hypothesis. Two species, R. flavefaciens and B. longum subsp. longum, with three metabolites, putrescine, xanthurenic acid, and pyridoxal, identified in the ruminal fluid, may point to a new health-promoting and disease-preventing approach for dairy cattle

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

Multi-messenger Observations of a Binary Neutron Star Merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ∼ 1.7 {{s}} with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of {40}-8+8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 {M}ȯ . An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ∼ 40 {{Mpc}}) less than 11 hours after the merger by the One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ∼10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ∼ 9 and ∼ 16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta.</p

台灣肖楠葉子抗腫瘤活性成分–Yatein及其作用機制

台灣肖楠（Calocedrus formosana Florn）為台灣珍貴的針葉樹種，且台灣肖楠葉子抽出成分已被證實具有細胞毒性、抗氧化及抗真菌等生物活性，實具有開發為天然抗癌製劑之潛力。因此，本論文將首次針對台灣肖楠葉子抽出成分及其活性化合物進行體內及體外抗腫瘤活性評估。所得結果發現，台灣肖楠葉子抽出成分中，以正己烷可溶部具有最佳細胞毒性。進一步以管柱層析方式將正己烷可溶部細分為10個次分離部，並針對各分離部進行細胞毒性評估後發現，各次分離部中以次分離部1及4具有較強的細胞毒性。 基於生物活性導向之分離策略，本研究續利用HPLC系統對次分離部1及4進行分離及純化。經HPLC分析後，由次分離部1中得到順式瓔柏酸（trans-Communic acid）及Isoabienol共2個化合物。而由次分離部4中則係得到松柏酸（Pinusolidic acid）及（-）-反式-3-（3,4-亞甲基二氧基芐基）-2-（3,4,5-三甲氧基芐基）丁內酯（Yatein）共2個化合物。各化合物經細胞毒性篩選後，發現以Yatein對A549及CL1-5細胞具有最強細胞毒殺效果，二者中又以對CL1-5細胞之效果較佳。由流式細胞儀分析結果顯示，Yatein可誘導A549及CL1-5細胞之細胞週期停滯於G2/M時期，同時亦可造成肺癌細胞株產生細胞凋亡現象。此外，經Yatein處理後之肺癌細胞株，其Cyclin B1及磷酸化Cdc 2等G2/M時期相關調節蛋白表現量會有明顯增加情形。然而，經Yatein處理後之A549及CL1-5細胞，其Cdc 2及Cdc 25c等調節蛋白之表現量並無明顯改變。而本論文之試驗結果亦發現，Yatein之抗肺癌作用機轉與上游之ATM/ATR及p53等調控路徑活化有密切的關連性。另一方面， Yatein可扮演微管去穩定劑之角色，進而干擾A549及CL1-5細胞之微管聚合動力學，此為Yatein誘導肺癌細胞株產生G2/M時期停滯可能原因之一。 此外，由體內試驗結果可以發現，將Yatein投予腫瘤異體移殖小鼠後，可有效降低腫瘤之體積以及重量，且對於小鼠體重及其日常攝食量則無明顯影響。基於上述結果，本論文證實Yatein在體外及體內模式中，具有良好的細胞毒性及抗腫瘤功效，顯示Yatein實具有進一步開發為抗非小細胞肺癌植物製劑之發展潛能。Calocedrus formosana Florin is a well-known softwood tree species in Taiwan. The leaves extract of C. formosana had been reported with excellent bioactivities such as cytotoxic, antioxidant and antifungi effects. According to these studies, the leaves extract of C. formosana may be a potential candidate for novel natural anticancer agent. In the present study, the anti-lung cancer efficacy of C. formosana leaves extract and its derived active phytocompounds, were evaluated using in vitro cell-based models and in vivo xenograft mice model for the first time. Among the crude extract and its derived fractions from leaves of C. formosana, the n-hexane fraction exhibited the best cytotoxicity potential. Following by column chromatography, 10 subfractions were obtained from the n-hexane fraction, and the cytotoxic effects of each subfraction were also determined in this study. The results revealed that the sunfractions 1 and 4 exhibited better cytotoxic potential than other subfractions. Based on the bioactivity-guided isolation principle, the subfractions 1 and 4 were then separated using HPLC system. After HPLC analyzed, trans-Communic acid and isoabienol were isolated from subfraction 1; pinusolidic acid and yatein were isolated from subfraction 4. Among these phytocompounds, yatein exhibited the best cytotoxicity in A549 and CL1-5 cells. In addition, the CL1-5 cells were more sensitive than A549 cells after yatein treatment. According to flow cytometry analysis, the result revealed that yatein induced G2/M arrest and apoptosis in these two lung cancer cell lines. Furthermore, the expression of G2/M arrest related regulatory proteins such as Cyclin B1 and p-Cdc 2 were increased after treatment with yatein in A549 and CL1-5 cells. However, the Cdc 2 and Cdc 25c expressions of A549 and CL1-5 cells were no significant difference between vehicle control group and yatein treatment group. The upstream pathways including ATM/ATR pathway and p53 pathway were also involved in the anti-ling cancer mechanism of yatein. In this study, we also found that yatein act as a microtubule destabilizer that interfered microtubule dynamic of A549 and CL1-5 cells, which is another possible reason for yatein induced significantly cell populations staying in G2/M arrest. On the other hand, the in vivo anti-lung cancer activity of yatein was also evaluated in this study using xenofraft mice model. The tumor size and weight in xenograft mice were decreased after yatein treatment. Accordingly, the daily diet intake and body weight of xenograft mice have no significant difference between the vehicle control group and the yatein treatment group. Based on these findings, it provides insight into the in vitro and in vivo anti-lung tumor efficacy of yatein, rendering this phytocompound a potential anticancer drug for NSCLC.目錄 i 表目次 iii 圖目次 v 摘要 1 Abstract 3 第一章 前言 5 第二章 文獻回顧 8 一、肖楠屬抽出成分及相關活性介紹 8 二、常見細胞死亡方式之介紹 15 三、天然物應用於抑制微管動態平衡之相關研究 27 四、木酚素細胞毒性相關研究然 31 第三章 材料與方法 34 一、試驗材料 34 二、台灣肖楠指標成分之定性與定量 34 三、體外細胞試驗 35 四、體內抗腫瘤活性試驗 42 五、統計分析 44 第四章 結果與討論 45 一、台灣肖楠葉子甲醇粗萃物及其各可溶部之細胞毒性評估 45 二、以生物活性為導向對正己烷可溶部進行初步篩選及分離 50 三、次分離部4對A549及CL1-5細胞細胞週期之影響 51 四、台灣肖楠葉子正己烷可溶部細胞毒性化合物之分離與鑑定 52 五、台灣肖楠葉子成分對人類肺癌細胞株之生長抑制效果 74 六、Yatein對肺癌細胞株細胞週期之影響 77 七、Yatein對肺癌細胞株產生細胞凋亡之影響 81 八、Yatein對肺癌細胞株細胞週期調控相關蛋白之影響 87 九、Yatein對肺癌細胞株細胞凋亡相關蛋白之影響 91 十、Yatein造成肺癌細胞DNA損壞並導致ATM/ATR路徑活化 94 十一、Yatein對肺癌細胞株微管聚合動力學之影響 101 十二、Yatein對肺癌細胞株產生ROS之影響 106 十三、Yatein與其他抗癌藥物之相互作用 109 十四、Yatein於A549細胞之異體移殖小鼠體內抗腫瘤功效 113 十五、Yatein抗非小細胞肺癌細胞生長之作用機轉 120 第五章 結論 122 參考文獻 12