Resveratrol targeting the Wnt signaling pathway: A focus on therapeutic activities

Wingless-type MMTV integration site (Wnt) signaling pathway is considered as an important pathway regulating a variety of biological processes such as tissue formation and homeostasis, cell proliferation, cell migration, cell differentiation, and embryogenesis. Impairment in the Wnt signaling pathway is associated with pathological conditions, particularly cancer. So, modulation of this pathway can be considered as a promising strategy and several drugs have been developed in line with this strategy. Resveratrol (Res) is a naturally occurring nutraceutical compound exclusively found in different fruits and nuts such as grape, peanut, and pistachio. This compound has favorable biological and therapeutic activities such as antioxidant, anti-inflammatory, antitumor, hepatoprotective, cardioprotective, and antidiabetic. At the present review, we demonstrate how Res modulates Wnt signaling pathway to exert its pharmacological effects.     

Tomato genetic resources and activities in Poland

The vegetables germplasm conservation programme in Poland was started in 1982, activities under this program resulted up to this date in building up a tomato germplasm collection of 782 accessions that are available for distribution to breeders and researchers in Poland and abroad. Between 1990 and 1999 we distributed 651 tomato seed samples to breeders and scientists in Poland, and 95 samples to users abroad. During 1990 – 1999 the 652 tomato accessions were evaluated for 43 traits of plants and fruits. Work is in progress to expand the collection and identify useful characteristics of the collected material, and to make use of them in breeding and other research works.     

A note on the activities of a solitary male baboon

This paper describes the behavior and activity patterns of a solitary adult male yellow baboon (Papio cynocephalus) living in the Amboseli National Park, Kenya. Social events surrounding the male's departure from his group, his contacts with other baboons while solitary, and events surrounding his return to the group are described in detail. The distribution of the male's time among several activity states, called histime budget, the average duration of these activities and the autocorrelation of activity states are analyzed and compared to the same measures of activity taken on group living males. The information presented indicates that a solitary male, even when injured, is not necessarily destined to die or to have a low reproductive potential.     

A note on the reduction of a risk of death

Abstract

Methods for assessing the gain of life expectancy by reducing the risks of death are examined. Depending on the method used, overestimation and underestimation of life expectancy may occur. Although the gain in life expectancy is not a linear function of the per cent reduction in mortality, a linear approximation may be used when the mortality rate is low. When the mortality rate is high, linear approximations tend to overestimate the years gained. A method using the parameter H⁽ⁱ⁾ developed by Keyfitz (1977) is adequate for low mortality rates such as with neoplasms. However, when mortality rates are high, as they are for cardiovascular‐renal diseases (CVD), Keyfitz's method tends to underestimate the gain in life expectancy. For CVD, Keyfitz's estimation is adequate below the 20 per cent reduction range. The magnitude of overestimation and underestimation are numerically evaluated based on the 1964 United States male mortality statistics.     

Superoxide scavenging by neelaredoxin: dismutation and reduction activities in anaerobes

A superfamily of mononuclear iron proteins, originally named desulfoferrodoxin and neelaredoxin, has been identified by in vivo and in vitro studies as scavengers of the superoxide anion radical. These proteins, whose genes are present in all the so-far known genomes from anaerobes and in the microaerophilic pathogen Treponema pallidum, show not only a considerable amino acid sequence identity but, most importantly, a common active iron site, Fe[His₄CysGlu], in the oxidized state which loses the glutamate ligand in the reduced form. The experimental evidence for the activity of these proteins as superoxide dismutases or as donor:superoxide oxidoreductases is discussed in this Commentary, giving particular emphasis to the neelaredoxin from the hyperthermophilic archaeon Archaeoglobus fulgidus.     

Chemical diversity and biological activities of the saponins isolated from Astragalus genus: focus on Astragaloside IV

Phytochemistry Reviews - Astragalus is a cosmopolitan genus characterised by a large number of species with an exceptional rate of diversification. Many of these species are used since ancient...     

Concluding remarks: symposium on Genetic Susceptibility to Environmental Toxicants

The symposium on "Genetic Susceptibility to Environmental Toxicants" provided a state-of-the-art forum on the role of genetic susceptibility involving exposures to occupational, dietary, and other environmental toxicants. While much of the work focused on single gene-environmental interactions, there was a clear understanding that multiple gene polymorphisms in a metabolic pathway would prove to be essential knowledge in better assessing health risks. A clear need to couple these advances with better measures of exposure was also appreciated, along with improved methods to conduct individual risk assessment procedures. The ethics of these new paradigms was also discussed.     

全球多边惠益分享机制:遗传资源获取和惠益分享谈判的新焦点

全球多边惠益分享机制(The Global Multilateral Benefit-Sharing Mechanism,GMBSM)问题是遗传资源的获取和惠益分享谈判进程中的重要问题. 《名古屋议定书》通过后,各方就建立全球多边惠益分享机制的必要性和模式进行了磋商.作者梳理了GMBSM问题的由来和主要内容,分析了遗传资源提供国和使用国的立场.非洲集团虽支持建立该机制,但限于能力,无法有效主导议题;巴西等部分提供国未表支持,担忧GMBSM不利于国家行使主权;使用国代表为拖延议题进程,提出许多技术性难题.结果表明,GMBSM议题可能成为《名古屋议定书》缔约方会议焦点,甚至可能因此产生《生物多样性公约》新的补充议定书,但其进程将十分艰难.为了更好地参与该议题谈判,我们认为国内应从外交、法律和技术层面做好以下准备工作:(1)加强与各谈判方的交流和沟通,特别要注重对非洲集团的工作;(2)开展法律研究,评估GMBSM与《生物多样性公约》、《联合国海洋法公约》及《南极条约》等国际条约的一致性;(3)尽早开展一系列国内调研,为参与GMBSM问题的讨论和磋商提供支持.     

A note on the kinetics of enzyme action: A decomposition that highlights thermodynamic effects

Michaelis and Menten’s mechanism for enzymatic catalysis is remarkable both in its simplicity and its wide applicability. The extension for reversible processes, as done by Haldane, makes it even more relevant as most enzymes catalyze reactions that are reversible in nature and carry in vivo flux in both directions. Here, we decompose the reversible Michaelis–Menten equation into three terms, each with a clear physical meaning: catalytic capacity, substrate saturation and thermodynamic driving force. This decomposition facilitates a better understanding of enzyme kinetics and highlights the relationship between thermodynamics and kinetics, a relationship which is often neglected. We further demonstrate how our separable rate law can be understood from different points of view, shedding light on factors shaping enzyme catalysis.     

Anthocyanins: Structural characteristics that result in unique metabolic patterns and biological activities

Interest in anthocyanins has increased immensely during the past decade. From these studies, it is clear that anthocyanins have unique properties: Anthocyanins are absorbed intact and absorption can be saturated; acylation of anthocyanins lowers their apparent absorption; anthocyanidin diglycosides in the form of sambubioside or rutinoside impart increased stability to the anthocyanin molecule; and the quantities excreted in urine are less than 0.1% of intake. However, 60–90% of the anthocyanins may disappear from the gastrointestinal tract within 4 h after a meal. What happens to the bulk of the anthocyanins that disappear is not clear. Degradation accounts for a part of this disappearance, but differs for the various aglycones and may be modified further by the nature of the aglycone glycosylation, which further complicates our understanding of this process. Anthocyanins may play an important role in health promotion in terms of obesity prevention, cardiovascular health, anti-inflammatory and anti-cancer effects.     

Anthocyanins: structural characteristics that result in unique metabolic patterns and biological activities

Interest in anthocyanins has increased immensely during the past decade. From these studies, it is clear that anthocyanins have unique properties: Anthocyanins are absorbed intact and absorption can be saturated; acylation of anthocyanins lowers their apparent absorption; anthocyanidin diglycosides in the form of sambubioside or rutinoside impart increased stability to the anthocyanin molecule; and the quantities excreted in urine are less than 0.1% of intake. However, 60-90% of the anthocyanins may disappear from the gastrointestinal tract within 4 h after a meal. What happens to the bulk of the anthocyanins that disappear is not clear. Degradation accounts for a part of this disappearance, but differs for the various aglycones and may be modified further by the nature of the aglycone glycosylation, which further complicates our understanding of this process. Anthocyanins may play an important role in health promotion in terms of obesity prevention, cardiovascular health, anti-inflammatory and anti-cancer effects.     

A note on the estimation of microbial glycosidase activities by dinitrosalicylic acid reagent

 In the estimation of glycosidase activity by dinitrosalicylic acid (DNS) reagent, the stoichiometry of DNS reduction was reported to increase proportionately with the increase in the number of glycosidic linkages present in oligosaccharides liberated by the enzyme. The relationship between increases in DNS reduction and increases in the number of glycosidic bonds was found to be represented by a part of a rectangular hyperbola. The increase was optimum with disaccharide and insignificant when the degree of polymerization (DP) was ≥10. The difference did not arise as a result of the DNSA discriminating between mono- and oligosaccharide oxidation. The relationship stemmed from the acidity of the hydroxyl group adjacent to the reducing group, which repressed DNS reduction. The acidity is likely to decrease with an increase in oligosaccharide chain length. It is suggested that DNS reduction is actually optimum and uniform for all oligosaccharides of DP ≥ 10 and that it is minimum for monosaccharide. Thus the introduction of rectification factors in the estimation of glycosidase activities by the DNS method appears to be justified. Received: 18 January 1999 / Received revision: 7 December 1999 / Accepted: 19 December 1999