Helenalin attenuates alcohol-induced hepatic fibrosis by enhancing ethanol metabolism,inhibiting oxidative stress and suppressing HSC activation

A compound was isolated from Centipeda minima using bioassay-guided screening. The structure of this compound was elucidated based on its spectral data, and it was identified as helenalin. The hepatoprotective effect of helenalin was evaluated using a liver fibrosis model induced by intragastric administration with alcohol within 24 weeks in rats. The results revealed that helenalin significantly prevented alcohol-induced hepatic injury and fibrogenesis, as evidenced by the decrease in serum aminotransferase, the attenuation of histopathological changes, and the inhibition of the hepatic fibrosis indicators, such as hyaluronic acid, type III precollagen, laminin, hydroxyproline and collagen α type I. Mechanistically, studies showed that helenalin expedited ethanol metabolism by enhancing the alcohol and aldehyde dehydrogenase activities. Furthermore, helenalin alleviated lipid peroxidation, recruited the antioxidative defense system, inhibited CYP2E1 activity, and reduced the inflammatory mediators, including TGF-β₁, TNF-α, IL-6 and IL-1β and myeloperoxidase, via down-regulation of NF-κB. Helenalin significantly decreased collagen deposition by reducing the profibrotic cytokines like transforming growth factor-β, platelet-derived growth factor-β and connective tissue growth factor, and promoted extracellular matrix degradation by modulating the levels of tissue inhibitor of matrix metalloproteinase-1 and matrix metalloproteinase-9. In addition, helenalin inhibited HSC activation as evidenced by the down-regulation of α-SMA and TGF-β levels. In conclusion, helenalin had a significant protective effect on chronic ethanol-induced hepatic fibrosis and may be a major bioactive ingredient of C. minima.     

A further note on the activation energy of diffusion

Summary The activation energy of diffusion can be expressed in terms of thermodynamic quantities such as entropy and enthalpy of sorption. A substantial simplification to such a published expression is presented.     

Activation of stress-responsive mitogen-activated protein kinase pathways in hybrid poplar (Populus trichocarpa x Populus deltoides)

Plant mitogen-activated protein kinase (MAPK) cascades are important amplifying modules that can rapidly transduce stress signals into various appropriate intracellular responses. Several extracellular regulated kinase (ERK)-type MAPKs involved in plant defense signaling have been identified in herbaceous species, but no MAPK cascade has yet been characterized in a tree species. We examined the signal transduction events that lead to activation of defense mechanisms in poplar, a major forest species of economic and ecological importance which is becoming the model tree system for studying stress and adaptation responses. We show that, in poplar cell suspensions and leaf tissue, chitosan, a non-host-specific elicitor, and ozone, a strong oxidant and atmospheric pollutant, induce rapid and transient activation of at least two myelin basic protein (MBP) kinases with apparent molecular masses of 44 and 47 kD. The chitosan- and ozone-activated kinases have characteristics of MAPKs-they preferentially phosphorylate MBP, require tyrosine and threonine phosphorylation to be activated and are specifically recognized by anti-ERK and anti-pERK antibodies. Moreover, activation of these poplar MAPKs by chitosan or ozone is dependent on the production of reactive oxygen species; the influx of calcium ions via membrane channels; the activation of an upstream, membrane-localized component; and a cognate MAPK kinase (MAPKK). These data suggest that biotic and abiotic challenges activate MAPKs in poplar, as in herbaceous species, which then function as a convergence point for pathogen defense and oxidant stress signaling cascades.     

一束穿越历史的理性之光——解读姜春云主编专著《偿还生态欠债——人与自然和谐探索》

在关乎共同利益及未来面前，人类似乎正在摈弃政治、宗教、信仰等偏见，渐渐在趋向大同。本刊在去年9月号上。对美国前副总统戈尔写的《无法忽视的真相》进行了解读。那本书以无可辩驳的事实，客观地展示了全球性的生态危机，指出：人类自救只有十年期。超过了这个期限、许多危机便无法逆转。无独有偶。在去年9月。新华出版社出版了姜春云主编的专著《偿还生态欠债——人与自然和谐探索》。此书展示的是中国的生态危机。与戈尔不同的是。此书不只列举了现象和危害，更重要的是对生态危机的深层原因进行了尖锐剖析。并借鉴国内外众多专家学者最新研究的成果，对解决生态危机提出了应对之策。该书内容翔实丰富。数据准确权威，方法科学实用。结论严谨缜密。这是一束穿越历史的理性之光，让几十年来沉迷在巨大发展的我们，看到了自身的疏忽以及由此欠下的生态巨债，看到了这种疏忽背后的种种因果链条，看到了走出困境走向希望的唯一之路。作为前奏，本刊新年1月号已先刊发了姜春云同志为该书写的序言，本篇以解读的方式对全书的内容进行隆重推介。限于篇幅，所作的解读也只能蜻蜒点水。但作为一个推介者，本刊希望所有关注中国未来发展的人，能够挤时间坐下来读读原著，让这束穿越历史的理性之光也穿越你的心灵．引导你真切地洞察我们的过去．现在及将来。     

A model describing axial flow of liquids through conifer wood

Summary A mathematical model has been derived for the prediction of the resistance to viscous liquid flow generated by tracheid lumina and various parts of the bordered pit structure. The model also takes into account changes in pit geometry occurring as the pit membrane deflects when a pressure differential is applied across it. Methods for checking whether flow is truly viscous are presented.Data calculated for Pinus sylvestris suggest that the permeability of earlywood differs markedly from that of latewood; that in latewood the pit apertures contribute significantly to the total resistance to flow; and that kinetic energy corrections to the Poiseuille viscous flow equation may be of some importance at high flow rates.The authors wish to acknowledge the encouragement of Professors Matthews and Roche.     

Oestrogenicity and effect on hepatic metabolism of the aqueous extract of the leaf mixture of Aloe buettneri,Dicliptera verticillata,Hibiscus macranthus and Justicia insularis

The aqueous extract of the leaf mixtures of Aloe buettneri, Dicliptera verticillata, Hibiscus macranthus and Justicia insularis given by oral route to immature female rats, at doses of 13, 49 and 94 mg/kg per day for 15 days induced a significant increase in ovarian and uteri weight as well as serum and ovarian oestradiol. Moreover, a significant decrease in liver of aminopyrine N-demethylase activity was noticed in treated animals.     

蝴蝶兰组培快繁技术的研究进展

综述蝴蝶兰组培快繁的研究进展,包括原球茎的来源、培养基及外源激素的使用等方面的研究成果,并分析了原球茎途径和丛芽途径的优缺点。     

In vitro metabolism in Sprague-Dawley rat liver microsomes of forsythoside A in different compositions of Shuang-Huang-Lian

Shuang–Huang–Lian (SHL), a traditional Chinese formula containing Lonicerae japonicae flos (LJF), Scutellariae radix (SR) and Forsythiae fructus (FF), is commonly used to treat acute upper respiratory tract infection, acute bronchitis and light pneumonia. Forsythoside A is one of the main active ingredients in Forsythiae fructus, a key herb in SHL. In the present study, effects of different compositions in SHL on the in vitro metabolism in Sprague–Dawley rat liver microsomes of forsythoside A were investigated. The observations from Sprague–Dawley rat liver microsomes in the presence of β-NADPH or UDPGA that forsythoside A may be the substrates of CYP3A4, CYP2C9, CYP1A2, UGT1A6, UGT1A3, UGT1A1 and UGT1A9; Chlorogenic acid may be the substrates of CYP3A4, CYP2C9, CYP1A2, CYP2C19, UGT1A6, UGT1A3 and UGT1A1; Baicalin may be the substrates of CYP3A4, CYP2C19, CYP1A2, UGT1A9, UGT1A1 and UGT1A3; Baicalein may be the substrates of CYP3A4, CYP2E1 and UGT1A6. It was also found that the residue of forsythoside A in SHL, FF + LJF and FF + SR was greatly increased compared with that in FF in Sprague–Dawley rat liver microsomes in the presence of β-NADPH or UDPGA, which indicated that the metabolism of forsythoside A in SHL may be influenced by chlorogenic acid in LJF acting on the CYP3A4, CYP2C9, CYP1A2, UGT1A6, UGT1A3 and UGT1A1; baicalin in SR acting on the CYP3A4, CYP1A2, UGT1A9, UGT1A1 and UGT1A3; baicalein acting on the CYP3A4 and UGT1A6 respectively.     

A hypothesis about the interaction of tree dominance and stand production through stand development

The development of forests over time involves changes in rates of growth of trees and stands, and changes in the competition and dominance between trees plays a large role in the overall development of stands. A hypothesis proposes that changes in the growth of trees and stands result from regular changes in dominance and the efficiency of resource use by dominant and non-dominant trees. Dominance is low prior to canopy closure, and efficiency of resource use is high for all trees. Increasing dominance near canopy closure reduces the efficiency of resource use by non-dominant trees, lowering overall stand growth. Later in stand development, the efficiency of resource use also declines for the largest trees, reducing the level of dominance in the stand. The dominance part of this hypothesis was examined for 150 years of stand development in two mixed-species stands in the Coast Range of Oregon. A quantitative index of dominance was minimal prior to the peak in stand growth near age 25–30 years, and then increased sharply as stand productivity declined. Dominance then declined after age 100 years as the growth rate of the 300 largest trees/ha began to decline. The dominance portion of the hypothesis was supported, and further testing may be useful.     

我国经济林高新技术产业建设的思考

在对国内外经济林生产现状和发展趋势进行概述的基础上,对我国未来经济林生产总体框架提出设想。现全国有经济林经营面积2000万hm2,近200个不同树种和多种经营方式,预计至2000年面积可达2600～3000万hm2,年产值超1000亿元。提出经济林生产应用高新技术的突破口主要有以下几个方面：培育新的品种;经济林生态系统的建立和管理;经济林产品的贮藏保鲜;产品的深加工和综合利用。在发展战略上可分近期、中期和远期目标,逐步实现。     

Responding to the Kyoto Protocol through forestry: A comparison of opportunities for several countries in Europe

Climate change has become an important environmental policy issue. Numerous carbon sequestration policy initiatives, potential benefits of which in environmental, economic and social terms could be substantial, are directed toward both woodland expansion and using of wood as a substitute for fossil fuels. There is a great deal of uncertainty, however, on how to define sustainability of such policies in a broadly acceptable and efficient way; how to translate sustainability requirements into policy guidelines; how to overcome market limitations and where to place biomass production in the general context of land use where contemporary agricultural change will likely be influential. On the basis of several countries from Europe (the United Kingdom, the Netherlands, Slovakia, and Ukraine) this paper highlights social and economic problems of moderating carbon emissions through afforestation. It provides an indication of whether forestry can offer a socially acceptable and a low-cost opportunity for carbon uptake. The conclusion is that along with carbon sequestration potential, the level of land use integration and the stage of institutional development play important roles for effective implementation of climate policies. The necessity is then to link these policies with regional developments, and to back them up with adequate economic incentives, appropriate institutions and with public engagement in environmental decision-making.     

Gelam honey inhibits lipopolysaccharide-induced endotoxemia in rats through the induction of heme oxygenase-1 and the inhibition of cytokines, nitric oxide, and high-mobility group protein B1

Malaysian Gelam honey has anti-inflammatory and antibacterial properties, a high antioxidant capacity, and free radical-scavenging activity. Lipopolysaccharide (LPS) stimulates immune cells to sequentially release early pro- and anti-inflammatory cytokines and induces the synthesis of several related enzymes. The aim of this study was to investigate the effect of the intravenous injection of honey in rats with LPS-induced endotoxemia. The results showed that after 4h of treatment, honey reduced cytokine (tumor necrosis factor-α, interleukins 1β, and 10) and NO levels and increased heme oxygenase-1 levels. After 24h, a decrease in cytokines and NO and an increase in HO-1 were seen in all groups, whereas a reduction in HMGB1 occurred only in the honey-treated groups. These results support the further examination of honey as a natural compound for the treatment of a wide range of inflammatory diseases.     

从国内博士和硕士论文统计分析透视森林公园研究的发展

以中国期刊学位论文数据库为资料来源,检索2000年~2014年期间我国以森林公园为研究对象的博硕士论文共460篇,统计分析这些学位论文在数量增长、专业背景、研究内容、研究案例等方面的情况,在一定程度上揭示出目前国内森林公园研究的现状与特点,并就未来森林公园研究工作提出了展望。