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Hiroshima-shi, Japan

Ohara M.,Hiroshima University | Ohyama Y.,Yasuda Womens University
Current Drug Metabolism

At present, dietary polyphenols are popular with consumers because regular consumption of polyphenol-rich foods is likely to be beneficial for human health. However, administrated polyphenols are extensively metabolized in the digestive tract or some other parts before reaching the target organs. Additionally, some of the polyphenols are photosensitive, easily oxidized and are in unfavorable forms. Therefore, a lot of work has been performed to ensure delivery of intact polyphenols to the target organs. We here summarize recent progress in polyphenol-delivery to individual organs, tissues, and cells, in regard to relatively new delivery systems. Polyphenol-delivery systems can be divided into three categories: (i) before delivery into the blood stream (skin, mouth, gastrointestine), (ii) in the blood stream (plasma), and (iii) after the blood stream (brain, spleen, bone marrow, kidney). Polyphenols before the delivery into blood stream must overcome several obstacles to avoid converting into inactive forms by commensal microorganisms, environmental pH, and some others. In the blood, plasma-polyphenol interactions and modifications are very effective for the bioavailability of polyphenols with numerous enzymes. Native forms of polyphenols, successfully out of the blood stream, further go through obstacles such as the blood brain barrier to reach target organs. Recent progress in delivering polyphenols is here discussed on 3 main delivery systems, nanoparticle, liposome, and microemulsion. Moreover, we also focused on delivery systems to intracellular organelles (cell surface, lysosome, mitochondria, nucleus), which are the final targets of polyphenols to perform their beneficial reactions. © 2014 Bentham Science Publishers. Source

Katsuno Y.,University of Tokyo | Ehata S.,University of Tokyo | Yashiro M.,Osaka City University | Yanagihara K.,Yasuda Womens University | And 2 more authors.
Journal of Pathology

Aldehyde dehydrogenase 1 (ALDH1) has been shown to serve as a marker for cancer-initiating cells (CICs), but little is known about the regulation of the CIC functions of ALDH1+ cancer cells. We isolated ALDH1+ cells from human diffuse-type gastric carcinoma cells and characterized these cells using an Aldefluor assay. ALDH1+ cells constituted 5-8% of the human diffuse-type gastric carcinoma cells, OCUM-2MLN and HSC-39; were more tumourigenic than ALDH1- cells; and were able to self-renew and generate heterogeneous cell populations. Using gene expression microarray analyses, we identified REG4 (regenerating islet-derived family, member 4) as one of the genes up-regulated in ALDH1+ cells, and thus as a novel marker for ALDH1+ tumour cells. Induced expression of REG4 enhanced the colony-forming ability of OCUM-2MLN cells, while knockdown of REG4 inhibited the tumourigenic potential of ALDH1+ cells. We further found that TGF-β signalling reduces the expression of ALDH1 and REG4, and the size of the ALDH1+ cell population. In human diffuse-type gastric carcinoma tissues, the expression of ALDH1 and REG4 correlated with each other, as assessed by immunohistochemistry, and ALDH1 expression correlated inversely with Smad3 phosphorylation as a measure of TGF-β signalling. These findings illustrate that, in diffuse-type gastric carcinoma, REG4 is up-regulated in ALDH1+ CICs, and that the increased tumourigenic ability of ALDH1+ cells depends on REG4. Moreover, TGF-β down-regulates ALDH1 and REG4 expression, which correlates with a reduction in CIC population size and tumourigenicity. Targeting REG4 in ALDH1+ CICs may provide a novel strategy in the treatment of diffuse-type gastric carcinoma. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Source

A synthetic method for novel 4-unsubstituted 2-phenyldihydropyrimidines having acyl and alkoxycarbonyl groups at the 5- and 6-positions was developed. The cyclization of 4-dimethylamino-1,3-diaza-1,3-butadiene having N-protecting groups (Boc, Cbz) with 1,2-disubstituted ethylenes, such as diethyl maleate, diethyl fumarate, (Z)-hex-3-ene-2,5-dione, (E)-1,4-diphenylbut-2-ene-1,4-dione, and unsymmetrical (E)-ethyl 4-oxo-4-phenylbut-2-enoate, following the elimination of a dimethylamino group proceeded smoothly, producing the corresponding dihydropyrimidines in good overall yield. The N-protecting group (Boc) could be easily removed to obtain N-unsubstituted dihydropyrimidines as a mixture of tautomers, and their tautomeric behavior was analyzed by 1H NMR spectroscopy. © 2013 Elsevier Ltd. All rights reserved. Source

Sada N.,Okayama University | Lee S.,Kawasaki Medical School | Katsu T.,Okayama University | Katsu T.,Yasuda Womens University | And 2 more authors.

Neuronal excitation is regulated by energy metabolism, and drug-resistant epilepsy can be suppressed by special diets. Here, we report that seizures and epileptiform activity are reduced by inhibition of the metabolic pathway via lactate dehydrogenase (LDH), a component of the astrocyte-neuron lactate shuttle. Inhibition of the enzyme LDH hyperpolarized neurons, which was reversed by the downstream metabolite pyruvate. LDH inhibition also suppressed seizures in vivo in a mouse model of epilepsy. We further found that stiripentol, a clinically used antiepileptic drug, is an LDH inhibitor. By modifying its chemical structure, we identified a previously unknown LDH inhibitor, which potently suppressed seizures in vivo. We conclude that LDH inhibitors are a promising new group of antiepileptic drugs. © 2015, American Association for the Advancement of Science. All rights reserved. Source

Tomioka H.,The University of Shimane | Tomioka H.,Yasuda Womens University
Current Pharmaceutical Design

Tuberculosis (TB) is one of the most important health concerns in the world, causing serious levels of morbidity and mortality, particularly in many developing countries. Unfortunately, the development of new anti-TB drugs with superior chemotherapeutic and prophylactic activity has been very slow. Thus, it is urgently necessary to develop novel kinds of antituberculosis drugs that exert their anti-Mycobacterium tuberculosis (MTB) activity through unique drug targets expressed by MTB organisms. At present, the drug targets of most current anti-TB drugs are primarily bacterial metabolic reactions and cell components that are indispensable to the growth and survival of MTB organisms in extracellular milieus, particularly in culture media. To develop novel and unique anti-TB drugs in the future, it is desirable to highlight the drug targets related to the bacterial ability to survive and replicate in host macrophages by escaping from a macrophage's bacterial killing mechanism during infection inside such phagocytes. For this purpose, it is reasonable to focus our research efforts on mycobacterial virulence factors that cross-talk and interfere with signaling pathways of host macrophages, because such virulence factors will provide intracellular milieus favorable to intramacrophage survival and growth of MTB. In this chapter, based on such a viewpoint and strategy, the present status of worldwide research on novel potential drug targets related to Toll-like receptor in the MTB pathogen will be described. © 2014 Bentham Science Publishers. Source

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