2021/12/13 更新

写真a

ナカムラ トシユキ
中村 俊之
NAKAMURA Toshiyuki
所属
環境生命科学学域 助教
職名
助教
外部リンク

学位

  • 博士

研究キーワード

  • 食品機能

研究分野

  • ライフサイエンス / 食品科学

 

論文

  • White rice ethanol extract is qualitatively, but not quantitatively, equivalent to that of brown rice as an antioxidant source. 国際誌

    Hongyan Wu, Toshiyuki Nakamura, Yingnan Guo, Miho Hirooka, Gongliang Zhang, Shintaro Munemasa, Yoshiyuki Murata, Akiko Fujita, Yoshimasa Nakamura

    Bioscience, biotechnology, and biochemistry   85 ( 10 )   2161 - 2168   2021年9月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The purpose of this study is to compare the potentials to exhibit biologically active antioxidant actions between white rice (WR) and brown rice (BR) in in vitro assays and a cellular model. The Trolox equivalent (TE) per 1 mg ethanol extract of WR for the 1,1-diphenyl-2-picrylhydrazyl assay was slightly higher than that of BR, whereas the TE per 1 g whole WR was much lower than that for BR. This tendency was very comparable to those for the oxygen radical absorbance capacity and total polyphenol content. Both of the ethanol extracts also similarly suppressed the hydrogen peroxide-induced cytotoxicity and enhanced the gene expression of drug-metabolizing enzymes. Based on the α-tocopherol quantity, its contribution to the cytoprotective effect of the rice extracts is very limited. Taken together, the ethanol extract of WR might be a qualitatively, but not quantitatively, equivalent source of antioxidative phytochemicals to that of BR.

    DOI: 10.1093/bbb/zbab133

    PubMed

    researchmap

  • Modulation of frequency and height of cytosolic calcium spikes by plasma membrane anion channels in guard cells. 国際誌

    Md Tahjib-Ul-Arif, Shintaro Munemasa, Toshiyuki Nakamura, Yoshimasa Nakamura, Yoshiyuki Murata

    Bioscience, biotechnology, and biochemistry   85 ( 9 )   2003 - 2010   2021年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Cytosolic calcium ([Ca2+]cyt) elevation activates plasma membrane anion channels in guard cells, which is required for stomatal closure. However, involvement of the anion channels in the [Ca2+]cyt elevation remains unclear. We investigated the involvement using Arabidopsis thaliana anion channel mutants, slac1-4 slah3-3 and slac1-4 almt12-1. Extracellular calcium induced stomatal closure in the wild-type plants but not in the anion channel mutant plants whereas extracellular calcium induced [Ca2+]cyt elevation both in the wild-type guard cells and in the mutant guard cells. The peak height and the number of the [Ca2+]cyt spike were lower and larger in the slac1-4 slah3-3 than in the wild type and the height and the number in the slac1-4 almt12-1 were much lower and much larger than in the wild type. These results suggest that the anion channels are involved in the regulation of [Ca2+]cyt elevation in guard cells.

    DOI: 10.1093/bbb/zbab118

    PubMed

    researchmap

  • A multidrug resistance-associated protein inhibitor is a potential enhancer of the benzyl isothiocyanate-induced apoptosis induction in human colorectal cancer cells. 国際誌

    Qifu Yang, Toshiyuki Nakamura, Masayuki Seto, Miku Miyagawa, Wensi Xu, Beiwei Zhu, Shintaro Munemasa, Yoshiyuki Murata, Yoshimasa Nakamura

    Journal of biochemical and molecular toxicology   35 ( 7 )   e22791   2021年7月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The increasing drug efflux through the ATP-binding cassette (ABC) transporters is the most plausible mechanism that mediates resistance to the anticancer phytochemicals, such as benzyl isothiocyanate (BITC), as well as chemotherapy drugs. To identify a potential component to overcome this resistance by combinatory utilization, we focused on multidrug resistance-associated proteins (MRPs) pumping various drug metabolites with glutathione as well as the organic anions. The pharmacological treatment of an MRP inhibitor, MK571, significantly potentiated the BITC-induced antiproliferation, coincided with the enhanced accumulation of BITC and glutathione in human colorectal cancer HCT-116 cells. MK571 also enhanced the apoptosis induction as well as activation of the mitogen-activated protein kinases and caspase-3, whereas it did not affect their basal levels. These results suggested that, since MRPs might play a pivotal role in the BITC efflux, MK571 potentiates the BITC-induced antiproliferation in human colorectal cancer cells through inhibition of the glutathione-dependent BITC efflux.

    DOI: 10.1002/jbt.22791

    PubMed

    researchmap

  • predominant rice phytochemicals and their disease-preventive effects

    Hongyan WU, Toshiyuki NAKAMURA, Yoshimasa NAKAMURA

    Journal of Environmental Science for Sustainable Society   10 ( Supplement )   MR01_p1 - MR01_p4   2021年4月

     詳細を見る

    掲載種別:研究論文(学術雑誌)   出版者・発行元:Graduate School of Environmental Science, Okayama University  

    DOI: 10.3107/jesss.10.mr01

    researchmap

  • Neither glutamate nor alanine but arginine sensitizes BY-2 cells to arsenate.

    Nahar, M.N., Prodhan, M.Y., Mimata, Y., Yonezawa, A., Nakamura, T., Nakamura, Y., Munemasa, S., Murata, Y.

    Biosci. Biotechnol. Biochem.   2021年

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

  • Luteolin suppresses 5-hydroxytryptamine elevation in stimulated RBL-2H3 cells and experimental colitis mice

    Naoko Suga, Akira Murakami, Hideyuki Arimitsu, Toshiyuki Nakamura, Yoshimasa Nakamura, Yoji Kato

    Journal of Clinical Biochemistry and Nutrition   69 ( 1 )   20 - 27   2021年

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    Increased 5-hydroxytryptamine may be associated with the development and progression of inflammatory bowel disease. In this study, we examined the suppressive effect of flavonoids on the increased intra- and extracellular 5-hydroxytryptamine levels in rat mast RBL-2H3 cells, known to produce 5-hydroxytryptamine by the phorbol 12-myristate 13-acetate stimulation. Among the flavonoids examined, luteolin and quercetin significantly reduced the cellular 5-hydroxytryptamine concentration. Gene and protein expression analyses revealed that luteolin significantly suppressed cellular tryptophan hydroxylase 1 expression induced by phorbol 12-myristate 13-acetate stimulation. Mitogen-activated protein kinase/extracellular signal-regulated kinase signaling was also suppressed by luteolin, suggesting that this pathway is one of targets of 5-hydroxytryptamine modulation by luteolin. An in vivo experimental colitis model was prepared by administering 2.5% dextran sodium sulfate in drinking water to C57BL/6 mice for seven days. The ingestion of 0.1% dietary luteolin suppressed the increasing 5-hydroxytryptamine in the colorectal mucosa. In conclusion, luteolin possesses a suppressive effect on extensive 5-hydroxytryptamine formation in both experimental RBL-2H3 cells and colitis models.

    DOI: 10.3164/JCBN.20-192

    Scopus

    researchmap

  • Stomatal response to isothiocyanates in Arabidopsis thaliana. 国際誌

    Sonya Afrin, Eiji Okuma, Md Tahjib-Ul-Arif, Md Sarwar Jahan, Toshiyuki Nakamura, Yoshimasa Nakamura, Shintaro Munemasa, Yoshiyuki Murata

    Journal of experimental botany   71 ( 22 )   6921 - 6931   2020年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Allyl isothiocyanate (AITC) induces stomatal closure accompanied by reactive oxygen species (ROS) production and glutathione (GSH) depletion in Arabidopsis thaliana. In this study, stomatal responses to three other isothiocyanates (ITCs), benzyl isothiocyanate (BITC), sulforaphane (SFN), and phenethyl isothiocyanate (PEITC), were investigated in A. thaliana. All these ITCs significantly induced stomatal closure, where PEITC and BITC were most effective. The selected ITCs also induced ROS accumulation, cytosolic alkalization, and GSH depletion in guard cells. Moreover, all ITCs increased the frequency of cytosolic free calcium ([Ca2+]cyt) spikes (transient elevation), while PEITC and BITC showed the highest frequency. There was a strong positive correlation between the number of [Ca2+]cyt spikes per guard cell and the decrease in stomatal aperture. Both cytosolic alkalization and GSH content have a positive correlation with the decrease in stomatal aperture, but ROS production did not have a significant correlation with the decrease in stomatal apertures. These results indicate that the molecules with a functional ITC group induce stomatal closure that is accompanied by GSH depletion, cytosolic alkalization, [Ca2+]cyt spikes, and ROS production, and that the former three cellular events, rather than ROS production, are highly correlated with the decrease in stomatal aperture.

    DOI: 10.1093/jxb/eraa420

    PubMed

    researchmap

  • Exogenous proline enhances antioxidant enzyme activities but does not mitigate growth inhibition by selenate stress in tobacco BY-2 cells. 国際誌

    Mousumi Khatun, Daiki Matsushima, Mohammad Saidur Rhaman, Eiji Okuma, Toshiyuki Nakamura, Yoshimasa Nakamura, Shintaro Munemasa, Yoshiyuki Murata

    Bioscience, biotechnology, and biochemistry   84 ( 11 )   2281 - 2292   2020年11月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Selenium (Se) causes oxidative damage to plants. Proline is accumulated as a compatible solute in plants under stress conditions and mitigates stresses. Selenate at 250 µM increased cell death and inhibited the growth of tobacco BY-2 cells while exogenous proline at 10 mM did not mitigate the inhibition by selenate. Selenate increased accumulation of Se and ROS and activities of antioxidant enzymes but not lipid peroxidation in the BY-2 cells. Proline increased Se accumulation and antioxidant enzyme activities but not either ROS accumulation or lipid peroxidation in the selenate-stressed cells. Glutathione (GSH) rather than ascorbic acid (AsA) mitigated the growth inhibition although both reduced the accumulation of ROS induced by selenate. These results indicate that proline increases both antioxidant enzyme activities and Se accumulation, which overall fails to ameliorate the growth inhibition by selenate and that the growth inhibition is not accounted for only by ROS accumulation. Abbreviations: APX: ascorbate peroxidase; AsA: ascorbic acid; BY-2: Bright Yellow-2; CAT: catalase; DAI: days after inoculation; DW: dry weight; FW: fresh weight; GSH: glutathione; ROS: reactive oxygen species.

    DOI: 10.1080/09168451.2020.1799747

    PubMed

    researchmap

  • The Myrosinases TGG1 and TGG2 Function Redundantly in Reactive Carbonyl Species Signaling in Arabidopsis Guard Cells.

    Mohammad Saidur Rhaman, Toshiyuki Nakamura, Yoshimasa Nakamura, Shintaro Munemasa, Yoshiyuki Murata

    Plant & cell physiology   61 ( 5 )   967 - 977   2020年5月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Myrosinase (β-thioglucoside glucohydrolase, enzyme nomenclature, EC 3.2.1.147, TGG) is a highly abundant protein in Arabidopsis guard cells, of which TGG1 and TGG2 function redundantly in abscisic acid (ABA)- and methyl jasmonate-induced stomatal closure. Reactive carbonyl species (RCS) are α,β-unsaturated aldehydes and ketones, which function downstream of reactive oxygen species (ROS) production in the ABA signalling pathway in guard cells. Among the RCS, acrolein is the most highly reactive, which is significantly produced in ABA-treated guard cells. To clarify the ABA signal pathway downstream of ROS production, we investigated the responses of tgg mutants (tgg1-3, tgg2-1 and tgg1-3 tgg2-1) to acrolein. Acrolein induced stomatal closure and triggered cytosolic alkalization in wild type (WT), tgg1-3 single mutants and in tgg2-1 single mutants, but not in tgg1-3 tgg2-1 double mutants. Exogenous Ca2+ induced stomatal closure and cytosolic alkalization not only in WT but also in all of the mutants. Acrolein- and Ca2+-induced stomatal closures were inhibited by an intracellular acidifying agent, butyrate, a Ca2+ chelator, ethylene glycol tetraacetic acid (EGTA) and a Ca2+ channel blocker, LaCl3. Acrolein induced cytosolic free calcium concentration ([Ca2+]cyt) elevation in guard cells of WT plants but not in the tgg1-3 tgg2-1 double mutants. Exogenous Ca2+ elicited [Ca2+]cyt elevation in guard cells of WT and tgg1-3 tgg2-1. Our results suggest that TGG1 and TGG2 function redundantly, not between ROS production and RCS production, but downstream of RCS production in the ABA signal pathway in Arabidopsis guard cells.

    DOI: 10.1093/pcp/pcaa024

    PubMed

    researchmap

  • Synthesis and characterization of conductive flexible cellulose carbon nanohorn sheets for human tissue applications. 国際誌

    Karthik Paneer Selvam, Taichi Nagahata, Kosuke Kato, Mayuko Koreishi, Toshiyuki Nakamura, Yoshimasa Nakamura, Takeshi Nishikawa, Ayano Satoh, Yasuhiko Hayashi

    Biomaterials research   24   18 - 18   2020年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Background: Conductive sheets of cellulose and carbon nanomaterials and its human skin applications are an interesting research aspect as they have potential for applications for skin compatibility. Hence it is needed to explore the effects and shed light on these applications. Method: To fabricate wearable, portable, flexible, lightweight, inexpensive, and biocompatible composite materials, carbon nanohorns (CNHs) and hydroxyethylcellulose (HEC) were used as precursors to prepare CNH-HEC (Cnh-cel) composite sheets. Cnh-cel sheets were prepared with different loading concentrations of CNHs (10, 20 50,100 mg) in 200 mg cellulose. To fabricate the bio-compatible sheets, a pristine composite of CNHs and HEC was prepared without any pretreatment of the materials. Results: The obtained sheets possess a conductivity of 1.83 × 10- 10 S/m and bio-compatible with human skin. Analysis for skin-compatibility was performed for Cnh-cel sheets by h-CLAT in vitro skin sensitization tests to evaluate the activation of THP-1 cells. It was found that THP-1 cells were not activated by Cnh-cel; hence Cnh-cel is a safe biomaterial for human skin. It was also found that the composite allowed only a maximum loading of 100 mg to retain the consistent geometry of free-standing sheets of < 100 μm thickness. Since CNHs have a unique arrangement of aggregates (dahlia structure), the composite is homogeneous, as verified by transmission electron microscopy (TEM) and, scanning electron microscopy (SEM), and other functional properties investigated by Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), conductivity measurement, tensile strength measurement, and skin sensitization. Conclusion: It can be concluded that cellulose and CNHs sheets are conductive and compatible to human skin applications.

    DOI: 10.1186/s40824-020-00194-3

    PubMed

    researchmap

  • Characterization of benzyl isothiocyanate extracted from mashed green papaya by distillation. 査読

    Nakamura T, Murata Y, Nakamura Y

    Food chemistry   299   125118   2019年11月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    DOI: 10.1016/j.foodchem.2019.125118

    PubMed

    researchmap

  • Dynamics of the Cellular Metabolism of Leptosperin Found in Manuka Honey. 査読 国際誌

    Yoji Kato, Masaki Kawai, Shota Kawai, Yayako Okano, Natsumi Rokkaku, Akari Ishisaka, Kaeko Murota, Toshiyuki Nakamura, Yoshimasa Nakamura, Shinichi Ikushiro

    Journal of agricultural and food chemistry   67 ( 39 )   10853 - 10862   2019年10月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Leptosperin (methyl syringate β-d-gentiobioside) is abundantly found in manuka honey, which is widely used because of its antibacterial and possible anti-inflammatory activities. The aim of this study was to examine the molecular mechanism underlying the metabolism of leptosperin. Five phytochemicals (leptosperin, methyl syringate (MSYR), glucuronate conjugate of MSYR (MSYR-GA), sulfonate conjugate of MSYR (MSYR-S), and syringic acid (SYR)) were separately incubated with HepG2 and Caco-2 cells. After incubation, we found that the concentration of MSYR decreased, whereas the concentrations of SYR, MSYR-GA, and MSYR-S increased. By profiling with inhibitors and carboxylesterases (CES1, 2), we found that the conversion from MSYR to SYR was mediated by CES1. Lipopolysaccharide-stimulated RAW264.7 cells restored MSYR-GA to MSYR possibly by the secreted β-glucuronidase. All of the mice administered with leptosperin, MSYR, or manuka honey showed higher MSYR (13.84 ± 11.51, 14.29 ± 9.19, or 6.66 ± 2.30 nM) and SYR (1.85 ± 0.66, 6.01 ± 1.20, or 8.16 ± 3.10 nM) levels in the plasma compared with that of the vehicle controls (3.33 ± 1.45 (MSYR) and 1.85 ± 0.66 (SYR) nM). The findings of our study indicate that the unique metabolic pathways of these compounds may account for possible functionalities of manuka honey.

    DOI: 10.1021/acs.jafc.9b03894

    PubMed

    researchmap

  • Covalent Modification of Phosphatidylethanolamine by Benzyl Isothiocyanate and the Resultant Generation of Ethanolamine Adduct as Its Metabolite. 査読

    Nakamura T, Hirakawa M, Nakamura Y, Ishisaka A, Kitamoto N, Murakami A, Kato Y

    Chemical research in toxicology   32 ( 4 )   638 - 644   2019年4月

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    DOI: 10.1021/acs.chemrestox.8b00331

    PubMed

    researchmap

  • The golgin protein giantin regulates interconnections between Golgi stacks 査読

    Ayano Satoh, Mitsuko Hayashi-Nishino, Takuto Shakuno, Junko Masuda, Mayuko Koreishi, Runa Murakami, Yoshimasa Nakamura, Toshiyuki Nakamura, Naomi Abe-Kanoh, Yasuko Honjo, Joerg Malsam, Sidney Yu, Kunihiko Nishino

    Frontiers in Cell and Developmental Biology   7 ( AUG )   160   2019年

     詳細を見る

    掲載種別:研究論文(学術雑誌)  

    © 2019 Satoh, Hayashi-Nishino, Shakuno, Masuda, Koreishi, Murakami, Nakamura, Nakamura, Abe-Kanoh, Honjo, Malsam, Yu and Nishino. Golgins are a family of Golgi-localized long coiled-coil proteins. The major golgin function is thought to be the tethering of vesicles, membranes, and cytoskeletal elements to the Golgi. We previously showed that knockdown of one of the longest golgins, Giantin, altered the glycosylation patterns of cell surfaces and the kinetics of cargo transport, suggesting that Giantin maintains correct glycosylation through slowing down transport within the Golgi. Giantin knockdown also altered the sizes and numbers of mini Golgi stacks generated by microtubule de-polymerization, suggesting that it maintains the independence of individual Golgi stacks. Therefore, it is presumed that Golgi stacks lose their independence following Giantin knockdown, allowing easier and possibly increased transport among stacks and abnormal glycosylation. To gain structural insights into the independence of Golgi stacks, we herein performed electron tomography and 3D modeling of Golgi stacks in Giantin knockdown cells. Compared with control cells, Giantin-knockdown cells had fewer and smaller fenestrae within each cisterna. This was supported by data showing that the diffusion rate of Golgi membrane proteins is faster in Giantin-knockdown Golgi, indicating that Giantin knockdown structurally and functionally increases connectivity among Golgi cisternae and stacks. This increased connectivity suggests that contrary to the cis-golgin tether model, Giantin instead inhibits the tether and fusion of nearby Golgi cisternae and stacks, resulting in transport difficulties between stacks that may enable the correct glycosylation of proteins and lipids passing through the Golgi.

    DOI: 10.3389/fcell.2019.00160

    Scopus

    PubMed

    researchmap

  • Benzyl isothiocyanate ameliorates lipid accumulation in 3T3-L1 preadipocytes during adipocyte differentiation. 査読

    Liang Y, Sasaki I, Takeda Y, Zhu B, Munemasa S, Nakamura T, Murata Y, Nakamura Y

    Bioscience, biotechnology, and biochemistry   82 ( 12 )   2130 - 2139   2018年12月

  • Methyl-β-cyclodextrin potentiates the BITC-induced anti-cancer effect through modulation of the Akt phosphorylation in human colorectal cancer cells. 査読

    Yang Q, Miyagawa M, Liu X, Zhu B, Munemasa S, Nakamura T, Murata Y, Nakamura Y

    Bioscience, biotechnology, and biochemistry   82 ( 12 )   2158 - 2167   2018年12月

  • Lymphatic metabolites of quercetin after intestinal administration of quercetin-3-glucoside and its aglycone in rats 査読

    Toshiyuki Nakamura, Chinatsu Kinjo, Yoshimasa Nakamura, Yoji Kato, Miyu Nishikawa, Masahiro Hamada, Noriyuki Nakajima, Shinichi Ikushiro, Kaeko Murota

    ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS   645   126 - 136   2018年5月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE INC  

    Quercetin is a major flavonoid, present as its glycosidic forms in plant foods. In this study, quercetin-3-glucoside (Q3G) was administered intraduodenally to thoracic lymph-cannulated rats, and its lymphatic transport was investigated. The resulting lymphatic and plasma metabolites were identified with LC-MS/MS and compared with those after administration of quercetin aglycone.The total concentration of quercetin metabolites in the lymph was about four times lower than that in the plasma, and quercetin and its methylated form isorhamnetin were detected as their glucuronides, sulfates and diglucuronides both in the lymph and the plasma after Q3G and quercetin administrations. The lymph levels of the glucuronides after Q3G administration were lower than those after quercetin administration, whereas those in the plasma showed the opposite pattern. Both the lymph and plasma levels of the sulfates after Q3G administration were lower than those after quercetin administration. Some of the intestinal metabolites like quercetin monoglucuronides were transported directly into the lymph and the hepatic metabolites like the diglucuronides were eventually transferred from the plasma into the lymph.These results indicate that the absorbed Q3G is partly transported into the intestinal lymph as quercetin metabolites. Deglycosylation in the enterocyte is also suggested to affect the subsequent metabolic pathways.

    DOI: 10.1016/j.abb.2018.03.024

    Web of Science

    PubMed

    researchmap

  • Physiological relevance of covalent protein modification by dietary isothiocyanates 査読

    Toshiyuki Nakamura, Naomi AbeKanoh, Yoshimasa Nakamura

    Journal of Clinical Biochemistry and Nutrition   62 ( 1 )   11 - 19   2018年1月

     詳細を見る

    記述言語:英語   出版者・発行元:The Society for Free Radical Research Japan  

    Isothiocyanates (ITCs), naturally occurring in abundance in crucif erous vegetables, are the most wellstudied organosulfur com pounds having an electrophilic reactivity. ITCs have been accepted as major ingredients of these vegetables that afford their health promoting potentials. ITCs are able to modulate protein functions related to drugmetabolizing enzymes, transporters, kinases and phosphatases, etc. One of the most important questions about the molecular basis for the health promoting effects of ITCs is how they modulate cellular target proteins. Although the molec ular targets of ITCs remains to be validated, dietary modulation of the target proteins via covalent modification by ITCs should be one of the promising strategies for the protection of cells against oxidative and inflammatory damage. This review discusses the plausible target proteins of dietary ITCs with an emphasis on pos sible involvement of protein modification in their health promot ing effects. The fundamental knowledge of ITCs is also included with consideration of the chemistry, intracellular behavior, and metabolism.

    DOI: 10.3164/jcbn.17-91

    Scopus

    PubMed

    researchmap

  • Benzyl isothiocyanate ameliorates acetaldehyde-induced cytotoxicity by enhancing aldehyde dehydrogenase activity in murine hepatoma Hepa1c1c7 cells 査読

    Yujia Liu, Momoko Yamanaka, Naomi Abe-Kanoh, Xiaoyang Liu, Beiwei Zhu, Shintaro Munemasa, Toshiyuki Nakamura, Yoshiyuki Murata, Yoshimasa Nakamura

    FOOD AND CHEMICAL TOXICOLOGY   108 ( Pt A )   305 - 313   2017年10月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    In the present study, we assessed benzyl isothiocyanate (BITC), an organosulfur compound from cruciferous vegetables, as a potential inducer of aldehyde dehydrogenase (ALDH) activity using murine hepatoma Hepa1c1c7 cells. BITC was shown to enhance not only the total ALDH activity, but also the ALDH activity of the cytosolic/microsomal and mitochondrial fraction. BITC also significantly increased the gene and protein expression of ALDH1A1, ALDH2 and ALDH3A1 in a concentration-dependent manner. Simultaneously, the gene expression of phase 2 drug-metabolizing enzymes, such as NAD(P)H: quinone oxidoreductase 1 and heme oxygenase-1, was increased by the BITC treatment. Western blot experiments revealed that BITC not only up-regulated the Nrf2 protein expression, but also stimulated the nuclear translocation of Nrf2. Furthermore, silencing Nrf2 reduced the basal and BITC-enhanced levels of the total activity and gene expression of ALDHs. The pretreatment of BITC completely mitigated the acetaldehyde-induced cytotoxicity, which was impaired by silencing Nrf2. The present study demonstrated that BITC has been identified as a potential inducer of the total ALDH activity to prevent the acetaldehyde-induced cytotoxicity. (C) 2017 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.fct.2017.08.016

    Web of Science

    PubMed

    researchmap

  • Inhibition of phosphatidylinositide 3-kinase ameliorates antiproliferation by benzyl isothiocyanate in human colon cancer cells 査読

    Xiaoyang Liu, Chiaki Takano, Tomomi Shimizu, Shintaro Yokobe, Naomi Abe-Kanoh, Beiwei Zhu, Toshiyuki Nakamura, Shintaro Munemasa, Yoshiyuki Murata, Yoshimasa Nakamura

    BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS   491 ( 1 )   209 - 216   2017年9月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE  

    In the present study, we clarified the role of phosphatidylinositide 3-kinase (PI3K) in antiproliferation induced by benzyl isothiocyanate (BITC) in human colorectal cancer cells. BITC simultaneously activated the PI3K/Akt/forkhead box 0 (FoxO) pathway, whereas it significantly inhibited the proliferation in human colorectal cancer cells. Inhibitory experiments using a PI3K selective inhibitor, LY294002 or NVP-BEZ235, significantly enhanced the BITC-induced antiproliferation and apoptotic cell population with the attenuation of the BITC-induced activation of the PI3K/Akt/FoxO survival pathway. Furthermore, BITC enhanced the insulin-activated PI3K/Akt/FoxO pathway, possibly through its inhibition of the protein tyrosine phosphatase 1B enzymatic activity. Taken together, these results suggested that the PI3K/Akt/FoxO pathway negatively regulates the BITC-induced antiproliferation in human colorectal cancer cells. (C) 2017 Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.bbrc.2017.07.078

    Web of Science

    PubMed

    researchmap

  • (-)-Epigallocatechin-3-gallate inhibits human angiotensin-converting enzyme activity through an autoxidation-dependent mechanism 査読

    Zhe Liu, Sayaka Nakashima, Toshiyuki Nakamura, Shintaro Munemasa, Yoshiyuki Murata, Yoshimasa Nakamura

    JOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY   31 ( 9 )   2017年9月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY  

    We investigated the molecular mechanisms involved in the angiotensin-converting enzyme (ACE) inhibition by (-)-epigallocatechin-3-gallate (EGCg), a major tea catechin. EGCg inhibited both the ACE activity in the lysate of human colorectal cancer cells and human recombinant ACE (rh-ACE) in a dose-dependent manner. Co-incubation with zinc sulfate showed no influence on the rh-ACE inhibition by EGCg, whereas it completely counteracted the inhibitory effect of ethylenediaminetetraacetic acid, a chelating-type ACE inhibitor. Although hydrogen peroxide was produced by the autoxidation of EGCg, hydrogen peroxide itself had little effect on the ACE activity. Conversely, the co-incubation of EGCg with borate or ascorbic acid significantly diminished the EGCg inhibition. A redox-cycling staining experiment revealed that rh-ACE was covalently modified by EGCg. A Lineweaver-Burk plot analysis indicated that EGCg inhibited the ACE activity in a non-competitive manner. These results suggested that EGCg might allosterically inhibit the ACE activity through oxidative conversion into an electrophilic quinone.

    DOI: 10.1002/jbt.21932

    Web of Science

    PubMed

    researchmap

  • Oleuropein aglycone enhances UCP1 expression in brown adipose tissue in high-fat-diet-induced obese rats by activating β-adrenergic signaling. 査読

    Oi-Kano Y, Iwasaki Y, Nakamura T, Watanabe T, Goto T, Kawada T, Watanabe K, Iwai K

    The Journal of nutritional biochemistry   40   209 - 218   2017年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1016/j.jnutbio.2016.11.009

    Web of Science

    PubMed

    researchmap

  • Inhibition of phosphatidylinositide 3-kinase impairs the benzyl isothiocyanate-induced accumulation of autophagic molecules and Nrf2 in human colon cancer cells 査読

    Xiaoyang Liu, Naomi Abe-Kanoh, Yujia Liu, Beiwei Zhu, Shintaro Munemasa, Toshiyuki Nakamura, Yoshiyuki Murata, Yoshimasa Nakamura

    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY   81 ( 11 )   2212 - 2215   2017年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:TAYLOR & FRANCIS LTD  

    The regulating role of phosphatidylinositide 3-kinase (PI3K) in benzyl isothiocyanate (BITC)-induced Nrf2 activation, contributing to the inducible expression of cytoprotective genes, was investigated. BITC significantly enhanced the accumulation of Nrf2 as well as autophagic molecules in human colorectal cancer HCT-116 cells. Experiments using a PI3K-specific inhibitor suggested that PI3K plays the key role in the non-canonical Nrf2 activation by BITC.

    DOI: 10.1080/09168451.2017.1374830

    Web of Science

    PubMed

    researchmap

  • Chitosan signaling in guard cells requires endogenous salicylic acid 査読

    Md. Yeasin Prodhan, Mohammad Issak, Toshiyuki Nakamura, Shintaro Munemasa, Yoshimasa Nakamura, Yoshiyuki Murata

    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY   81 ( 8 )   1536 - 1541   2017年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:TAYLOR & FRANCIS LTD  

    An elicitor chitosan (CHT) induces stomatal closure but the mechanism remains to be clarified. A phytohormone salicylic acid (SA) is crucial for elicitor-induced defense signaling in plants. Here we investigated whether endogenous SA is required for CHT signaling in guard cells. In the SA-deficient nahG mutant, treatment of CHT did not induce either apoplastic reactive oxygen species (ROS) production or stomatal closure but co-treatment of CHT and SA induced both apoplastic ROS production and stomatal closure, indicating the involvement of endogenous SA in CHT-induced apoplastic ROS production and CHT-induced stomatal closure. Furthermore, CHT induced transient cytosolic free calcium concentration increments in the nahG mutant in the presence of exogenous SA but not in the absence of exogenous SA. These results provide evidence that endogenous SA is a crucial element in CHT-induced stomatal closure.

    DOI: 10.1080/09168451.2017.1332979

    Web of Science

    PubMed

    researchmap

  • Exogenous proline enhances the sensitivity of Tobacco BY-2 cells to arsenate 査読

    Mst Nur-E-Nazmun Nahar, Mohammad Muzahidul Islam, Md. Anamul Hoque, Anna Yonezawa, Md. Yeasin Prodhan, Toshiyuki Nakamura, Yoshimasa Nakamura, Shintaro Munemasa, Yoshiyuki Murata

    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY   81 ( 9 )   1726 - 1731   2017年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:TAYLOR & FRANCIS LTD  

    Arsenic causes physiological and structural disorders in plants. Proline is accumulated as a compatible solute in plants under various stress conditions and mitigates stresses. Here, we investigated the effects of exogenous proline on tobacco Bright Yellow-2 (BY-2) cultured cells under AsO4- stress. Arsenate did not inhibit BY-2 cell growth at 40 and 50 mu M but did it at 60 mu M. Proline at 0.5 to 10 mM did not affect the cell growth but delayed it at 20 mM. At 40 mu M AsO4-, neither 0.5 mM nor 1 mM proline affected the cell growth but 10 mM proline inhibited it. In the presence of AsO4-, 10 mM proline increased the number of Evans Blue-stained (dead) cells and decreased the number of total cells. Together, our results suggest that exogenous proline does not alleviate arsenate toxicity but enhances the sensitivity of BY-2 cells to arsenate.

    DOI: 10.1080/09168451.2017.1340088

    Web of Science

    PubMed

    researchmap

  • 3,4-Dihydroxyphenylacetic acid is a potential aldehyde dehydrogenase inducer in murine hepatoma Hepa1c1c7 cells 査読

    Yujia Liu, Ayuki Kurita, Sayaka Nakashima, Beiwei Zhu, Shintaro Munemasa, Toshiyuki Nakamura, Yoshiyuki Murata, Yoshimasa Nakamura

    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY   81 ( 10 )   1978 - 1983   2017年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:TAYLOR & FRANCIS LTD  

    3,4-Dihydroxyphenylacetic acid (DOPAC) is one of the major colonic microflora-produced catabolites of quercetin glycosides, such as quercetin 4-glucoside derived from onion. Here, we investigated whether DOPAC modulates the aldehyde dehydrogenase (ALDH) activity and protects the cells from the acetaldehyde-induced cytotoxicity in vitro. DOPAC was shown to enhance not only the total ALDH activity, but also the gene expression of ALDH1A1, ALDH2 and ALDH3A1 in a concentration-dependent manner. DOPAC simultaneously stimulated the nuclear translocation of NFE2-related factor 2 and aryl hydrocarbon receptor. The pretreatment of DOPAC completely protected the cells from the acetaldehyde-induced cytotoxicity. The present study suggested that DOPAC acts as a potential ALDH inducer to prevent the alcohol-induced abnormal reaction.

    DOI: 10.1080/09168451.2017.1361809

    Web of Science

    PubMed

    researchmap

  • A novel tag-free probe for targeting molecules interacting with a flavonoid catabolite 査読

    Sayaka Nakashima, Zhe Liu, Yuya Yamaguchi, Shunya Saiki, Shintaro Munemasa, Toshiyuki Nakamura, Yoshiyuki Murata, Yoshimasa Nakamura

    Biochemistry and Biophysics Reports   7   240 - 245   2016年9月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Elsevier B.V.  

    3,4-Dihydroxyphenylacetic acid (DOPAC) is one of the colonic microflora-produced catabolites of quercetin 4'-glucoside (Q4'G). Although the interaction of DOPAC with cellular proteins might be involved in its biological activity, the actual proteins have not yet been identified. In this study, we developed a novel tag-free DOPAC probe to label the targeted proteins by the copper(I)-catalyzed azide alkyne cycloaddition (CuAAC) and verified its efficacy. Various labeled proteins were detected by the DOPAC probe with the azide labeled biotin and a horseradish peroxidase (HRP)-streptavidin complex. Furthermore, a pulldown assay identified Keap1 and aryl hydrocarbon receptor (AhR) as the target proteins for the phase 2 enzyme up-regulation.

    DOI: 10.1016/j.bbrep.2016.06.020

    Scopus

    PubMed

    researchmap

  • Activation of transient receptor potential ankyrin 1 by quercetin and its analogs 査読

    Toshiyuki Nakamura, Noriyuki Miyoshi, Takeshi Ishii, Miyu Nishikawa, Shinichi Ikushiro, Tatsuo Watanabe

    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY   80 ( 5 )   949 - 954   2016年5月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:TAYLOR & FRANCIS LTD  

    The agonistic activity of quercetin and its analogs towards the transient receptor potential ankyrin 1 (TRPA1) has been experimentally investigated. The human TRPA1 was expressed in HEK293T cells using a tetracycline-inducible system. The activation of TRPA1 was evaluated by a fluo-4 fluorescence assay based on calcium sensing. The results of a structure-activity relationship study led to the selection of six flavonoids, all of which activated the TRPA1 channel in a dose-dependent manner. Notably, the activation of TRPA1 by these flavonoid aglycones was completely inhibited by the co-treatment of the HEK293T cells with the TRPA1-specific antagonist, HC-030031. Several flavonoid glycosides and metabolites were also evaluated, but did not activate the TRPA1 except for methylated quercetin. On the other hand, TRPV1 (vanilloid receptor) did not respond to any of the flavonoids evaluated in this study. Therefore, these data suggest that the flavonoids would be promising ligands for the TRPA1.

    DOI: 10.1080/09168451.2015.1132148

    Web of Science

    PubMed

    researchmap

  • Galloylated catechins as potent inhibitors of angiotensin converting enzyme

    Zhe Liu, Toshiyuki Nakamura, Shintaro Munemasa, Yoshiyuki Murata, Yoshimasa Nakamura

    Food Science and Technology Research   22 ( 6 )   847 - 851   2016年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Japanese Society for Food Science and Technology  

    In the present study, we investigated the inhibitory effects of four tea catechins, including (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg) and (-)-epigallocatechin gallate (EGCg), on angiotensin converting enzyme (ACE) activity in vitro. Each catechin treatment significantly reduced the ACE activity with the order of potency being EGCg &gt
    ECg &gt
    EGC = EC. The addition of 1 mM borate significantly recovered the reduced ACE activities by tea catechins, suggesting that hydroxyl groups at the B-ring or at a galloyl moiety play an important role in the ACE-inhibitory mechanism. The covalent modification of ACE by tea catechins was also observed by a redox-cycling staining experiment. A Lineweaver-Burk plot indicated that EGC and ECg were noncompetitive inhibitors. The galloylated catechins might more potently inhibit ACE activity in an allosteric manner through the interaction of the galloyl moiety with the non-catalytic site of ACE.

    DOI: 10.3136/fstr.22.847

    Scopus

    researchmap

  • Location of α-tocopherol and α-tocotrienol to heterogeneous cell membranes and inhibition of production of peroxidized cholesterol in mouse fibroblasts 査読

    Toshiyuki Nakamura, Ayako Noma, Junji Terao

    Journal of the Korean Physical Society   3 ( 1 )   1 - 6   2014年9月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Korean Physical Society  

    Background: α-Tocopherol (α-T) and α-tocotrienol (α-T3) are well recognized as lipophilic antioxidants. Nevertheless, there is limited knowledge on their location in heterogeneous cell membranes. We first investigated the distribution of α-T and α-T3 to the cholesterol-rich microdomains (lipid rafts and caveolae) of heterogeneous cell membranes by incubating these antioxidants with cultured mouse fibroblasts.
    Findings: Levels of cellular uptake for α-T and α-T3 were adjusted to the same order, as that of the latter was much more efficient than that of the former in the cultured cells. After ultracentrifugation, α-T and α-T3 were partitioned to the microdomain fractions. When the distribution of α-T and α-T3 was further confirmed by using methyl-β-cyclodextrin (which removes cholesterol from membranes), α-T was suggested to be distributed to the microdomains (approx. 9% of the total uptake). The same treatment did not affect α-T3 content in the microdomain fractions, indicating that α-T3 is not located in these cholesterol-rich domains. However, α-T and α-T3 significantly inhibited the production of peroxidized cholesterol when cells were exposed to ultraviolet-A light.
    Conclusions: These results suggest that α-T and α-T3 can act as membranous antioxidants against photo-irradiated cholesterol peroxidation irrespective of their distribution to cholesterol-rich microdomains.

    DOI: 10.1186/2193-1801-3-550

    Scopus

    researchmap

  • Plasma metabolites of dietary flavonoids after combination meal consumption with onion and tofu in humans 査読

    Toshiyuki Nakamura, Kaeko Murota, Shun Kumamoto, Kazuhiro Misumi, Noriko Bando, Shinichi Ikushiro, Nobuyuki Takahashi, Keiko Sekido, Yoji Kato, Junji Terao

    MOLECULAR NUTRITION & FOOD RESEARCH   58 ( 2 )   310 - 317   2014年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY  

    Scope: The effect of food combination on metabolic profile in postprandial plasma has hardly been reported. We investigated the absorption and metabolism of quercetin and soy isoflavones in humans after combination meal consumption.Methods and results: Five healthy volunteers ingested sauteed onion and tofu, and the plasma metabolites of quercetin and isoflavones were analyzed. Quercetin and genistein were incubated with human intestinal Caco-2 cells and human hepatoma HepG2 cells to further analyze the influence of simultaneous supply to the small intestine and the liver. Glucuronosyl conjugates of quercetin and methylated quercetin were the major plasma metabolites in the case of onion intake. Plasma metabolites with the single serving of tofu were both glucuronide and sulfate metabolites of isoflavones. Interestingly, quercetin sulfate was only detected after the combined intake of sauteed onion and tofu, accompanied with a decrease in sulfated isoflavones. Besides, quercetin was shown as the preferential substance for phase II enzymes over genistein in both Caco-2 and HepG2 cells.Conclusion: These results indicate that, when flavonoids and isoflavonoids were ingested together, the metabolic conversions in the small intestine and/or the liver could be altered, resulting in the variation of the postprandial profiles of the plasma metabolites.

    DOI: 10.1002/mnfr.201300234

    Web of Science

    PubMed

    researchmap

  • The human bitter taste receptor hTAS2R39 is the primary receptor for the bitterness of theaflavins 査読

    Toyomi Yamazaki, Miki Sagisaka, Riko Ikeda, Toshiyuki Nakamura, Noriko Matsuda, Takeshi Ishii, Tsutomu Nakayama, Tatsuo Watanabe

    Bioscience, Biotechnology and Biochemistry   78 ( 10 )   1753 - 1756   2014年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Japan Society for Bioscience Biotechnology and Agrochemistry  

    We purified several hundred mgs of four major theaflavins (theaflavin, theaflavin-3-O-gallate, theaflavin-3′-O-gallate, and theaflavin-3,3′-O-digallate). Among the 25 hTAS2Rs expressed in HEK293T cells, hTAS2R39 and hTAS2R14 were activated by theaflavins. Both hTAS2R39 and hTAS2R14 responded to theaflavin-3′-O-gallate. In addition, hTAS2R39 was activated by theaflavin and theaflavin-3,3′-O-gallate, but not by theaflavin-3-O-gallate. In contrast, hTAS2R14 responded to theaflavin-3-O-gallate.

    DOI: 10.1080/09168451.2014.930326

    Scopus

    PubMed

    researchmap

  • Immunomodulatory activity of enzymatically synthesized glycogen and its digested metabolite in a co-culture system consisting of differentiated Caco-2 cells and RAW264.7 macrophages 査読

    Michiko Yasuda, Takashi Furuyashiki, Toshiyuki Nakamura, Ryo Kakutani, Hiroki Takata, Hitoshi Ashida

    FOOD & FUNCTION   4 ( 9 )   1387 - 1393   2013年9月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ROYAL SOC CHEMISTRY  

    Previously, we developed enzymatically synthesized glycogen (ESG) from starch, and showed its immunomodulatory and dietary fiber-like activities. In this study, we investigated the metabolism of ESG and its immunomodulatory activity using differentiated Caco-2 cells as a model of the intestinal barrier. In a co-culture system consisting of differentiated Caco-2 cells and RAW264.7 macrophages, mRNA expression of IL-6, IL-8, IL-1 beta and BAFF cytokines was up-regulated in Caco-2 cells and IL-8 production in basolateral medium was induced after 24 h apical treatment with 5 mg ml(-1) of ESG. The mRNA level of iNOS was also up-regulated in RAW264.7 macrophages. After characterization of the binding of anti-glycogen monoclonal antibodies (IV58B6 and ESG1A9) to ESG and its digested metabolite resistant glycogen (RG), an enzyme-linked immunosorbent assay (ELISA) system was developed to quantify ESG and RG. Using this system, we investigated the metabolism of ESG in differentiated Caco-2 cells. When ESG (7000 kDa, 5 mg ml(-1)) was added to the apical side of Caco-2 monolayers, ESG disappeared and RG (about 3000 kDa, 3.5 mg ml(-1)) appeared in the apical solution during a 24 h incubation. Neither ESG nor RG was detected in the basolateral solution. In addition, both ESG and RG were bound to TLR2 in Caco-2 cells. In conclusion, we suggest that ESG is metabolized to a RG-like structure in the intestine, and this metabolite activates the immune system via stimulation of the intestinal epithelium, although neither ESG nor its metabolite could permeate the intestinal cells under our experimental conditions. These results provide evidence for the beneficial function of ESG as a food ingredient.

    DOI: 10.1039/c3fo60035a

    Web of Science

    PubMed

    researchmap

  • Plasma HDL Reduces Nonesterified Fatty Acid Hydroperoxides Originating from Oxidized LDL: a Mechanism for Its Antioxidant Ability 査読

    Mari Kotosai, Sachiko Shimada, Mai Kanda, Namiko Matsuda, Keiko Sekido, Yoshibumi Shimizu, Akira Tokumura, Toshiyuki Nakamura, Kaeko Murota, Yoshichika Kawai, Junji Terao

    LIPIDS   48 ( 6 )   569 - 578   2013年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY  

    The antioxidant property of plasma high-density lipoprotein (HDL) is thought to be involved in potential anti-atherogenic effects but the exact mechanism is not known. We aimed to reveal the contribution of HDL on the elimination of lipid hydroperoxides (LOOH) derived from oxidized low-density lipoprotein (LDL). Oxidized LDL prepared by copper ion-induced oxidation contained nonesterified fatty acid hydroperoxides (FFA-OOH) and lysophosphatidylcholine (lysoPtdCho), in addition to cholesteryl ester hydroperoxides (CE-OOH) and phosphatidylcholine hydroperoxides (PtdCho-OOH). A platelet-activating factor-acetylhydrolase (PAF-AH) inhibitor suppressed formation of FFA-OOH and lysoPtdCho in oxidized LDL. Among LOOH species, FFA-OOH was preferentially reduced by incubating oxidized LDL with HDL. HDL exhibited selective FFA-OOH reducing ability if it was mixed with a liposomal solution containing FFA-OOH, CE-OOH and PtdCho-OOH. Two-electron reduction of the hydroperoxy group to the hydroxy group was confirmed by the formation of 13-hydroxyoctadecadienoic acid from 13-hydroperoxyoctadecadienoic acid in HPLC analyses. This reducing effect was also found in apolipoprotein A-1 (apoA-1). FFA-OOH released from PtdCho-OOH due to PAF-AH activity in oxidized LDL undergo two-electron reduction by the reducing ability of apoA1 in HDL. This preferential reduction of FFA-OOH may participate in the mechanism of the antioxidant property of HDL.

    DOI: 10.1007/s11745-013-3779-1

    Web of Science

    PubMed

    researchmap

  • Non-selective distribution of isomeric cholesterol hydroperoxides to microdomains in cell membranes and activation of matrix metalloproteinase activity in a model of dermal cells 査読

    Toshiyuki Nakamura, Ayako Noma, Sachiko Shimada, Nanase Ishii, Noriko Bando, Yoshichika Kawai, Junji Terao

    Chemistry and Physics of Lipids   174   17 - 23   2013年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Elsevier Ireland Ltd  

    Cholesterol hydroperoxides (ChOOHs) are included as lipid peroxidation products in the skin exposed to ultraviolet (UV) light irradiation. They may exert physicochemical actions affecting biomembrane rigidity because cholesterol is one of the major components of cell membranes. We investigated the distribution of isomeric ChOOHs in heterogeneous cell membranes with different lipid profiles using mouse fibroblast NIH-3T3 cells as a model of the dermis. Before and after UVA irradiation in the presence of hematoporphyrin, cell membranes were partitioned to microdomains (lipid rafts and caveolae) containing a higher amount of cholesterol and non-microdomains (containing a lower amount of cholesterol) by ultracentrifugation. By a combination of diphenylpyrenylphosphine-thin-layer chromatography blotting analyses and gas chromatography-electron ionization-mass spectrometry/selected ion monitoring analyses, ChOOH isomers were determined as their trimethylsilyloxyl derivatives. Cholesterol 5α-, 7α- and 7β-hydroperoxide were found as isomeric ChOOHs before irradiation. The amounts of the three ChOOH isomers increased significantly after photoirradiation for 2 h. No difference was observed between microdomains and non-microdomains with regard to the ratio of the amounts of isomeric ChOOHs to that of cholesterol, suggesting that these ChOOH isomers were distributed equally in both parts depending on cholesterol content. When cells were treated with a purified mixture of ChOOH isomers, cell membranes incorporated ChOOHs into microdomains as well as non-microdomains evenly. Cellular matrix metalloproteinase-9 (MMP-9) activity was elevated by treatment with the purified mixture of ChOOH isomers. These results strongly suggest that ChOOHs accumulate in cell membranes irrespective of the heterogeneous microstructure and promote MMP activity if dermal cells are exposed to photodynamic actions. © 2013 Elsevier Ireland Ltd. All rights reserved.

    DOI: 10.1016/j.chemphyslip.2013.05.004

    Scopus

    PubMed

    researchmap

  • Fermented Tea Improves Glucose Intolerance in Mice by Enhancing Translocation of Glucose Transporter 4 in Skeletal Muscle 査読

    Yoko Yamashita, Lihua Wang, Zhang Tinshun, Toshiyuki Nakamura, Hitoshi Ashida

    JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY   60 ( 45 )   11366 - 11371   2012年11月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER CHEMICAL SOC  

    The antihyperglycemic effects of tea are well documented. However; the effects of fermented tea on the translocation of glucose transporter 4 (GLUT4), the major glucose transporter for glucose uptake in the postprandial period, in skeletal muscle and the underlying molecular mechanisms are not fully understood. This study investigated the translocation of GLUT4 and its related signaling pathways in skeletal muscle of male ICR mice given fermented tea. Intake of oolong, black, or pu-erh tea for 7 days enhanced GLUT4 translocation to the plasma membrane of skeletal muscle. Each type of fermented tea stimulated the phosphorylation of phosphoinositide 3-kinase (PI3K), Akt/protein kinase B, and AMP-activated protein kinase (AMPK). Fermented tea also increased the protein expression of insulin receptor. These results strongly suggest that fermented tea activates both PI3K/Akt- and AMPK-dependent signaling pathways to induce GLUT4 translocation and increases the expression of insulin receptor to improve glucose intolerance.

    DOI: 10.1021/jf303597c

    Web of Science

    PubMed

    researchmap

  • Absorption and metabolism of 4-hydroxyderricin and xanthoangelol after oral administration of Angelica keiskei (Ashitaba) extract in mice 査読

    Toshiyuki Nakamura, Takahiro Tokushima, Kyuichi Kawabata, Norio Yamamoto, Masaaki Miyamoto, Hitoshi Ashida

    ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS   521 ( 1-2 )   71 - 76   2012年5月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE INC  

    To investigate the absorption and metabolism of 4-hydroxyderricin and xanthoangelol, we established an analytical method based on liquid chromatography-tandem mass spectrometry and measured these compounds, in the plasma, urine, feces, liver, kidney, spleen, muscle and white adipose tissues of mice orally administered with Ashitaba extract (50-500 mg/kg body weight). 4-Hydroxyderricin and xanthoangelol were quickly absorbed into the plasma, with time-to-maximum plasma concentrations of 2 and 0.5 h for 4-hydroxyderricin and xanthoangelol, respectively. Although these compounds have similar structures, the total plasma concentration of 4-hydroxyderricin and its metabolites was approximately 4-fold greater than that of xanthoangelol and its metabolites at 24 h. 4-Hydroxyderricin and xanthoangelol were mostly excreted in their aglycone forms and related metabolites (glucuronate and/or sulfate forms) in urine between 2 and 4 h after oral administration of Ashitaba extract. On the other hand, these compounds were only excreted in their aglycone forms in feces. When tissue distribution of 4-hydroxyderricin and xanthoangelol was estimated 2 h after administration of Ashitaba extract, both compounds were detected in all of the tissues assessed, mainly in their aglycone forms, except in the mesenteric adipose tissue. These results suggest that 4-hydroxyderricin and xanthoangelol are rapidly absorbed and distributed to various tissues. (C) 2012 Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.abb.2012.03.013

    Web of Science

    PubMed

    researchmap

  • Comparative analysis of carbohydrate-binding specificities of two anti-glycogen monoclonal antibodies using ELISA and surface plasmon resonance 査読

    Sachiko Nakamura-Tsuruta, Michiko Yasuda, Toshiyuki Nakamura, Eri Shinoda, Takashi Furuyashiki, Ryo Kakutani, Hiroki Takata, Yoji Kato, Hitoshi Ashida

    CARBOHYDRATE RESEARCH   350   49 - 54   2012年3月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCI LTD  

    For immunological experiments on glycogens, anti-glycogen antibodies are indispensable to capture, detect, and visualize sugar molecules. An anti-glycogen monoclonal antibody (IV58B6) and newly constructed antibody (ESG1A9mAb) have a common immunoglobulin type (IgM) and binding ability to glycogens, but overall possess different binding features. Therefore, they may prove useful for the construction of an advanced system of quantitative ELISA based on their molecular structures. For this purpose, detailed information on the carbohydrate-specificities of ESG1A9mAb and IV58B6 is first required, but their fine specificities for various types of glycogens have not been elucidated. To overcome this problem, we performed interaction analysis by ELISA of ESG1A9mAb and IV58B6 toward 15 glucose polymers, that is, 5 enzymatically-synthesized glycogens (ESGs), 6 natural source glycogens (NSGs), 3 enzymatically digested glycogens (EDGs), and soluble starch. To provide a more detailed analysis, we determined the association constants (K-a) of the two antibodies toward these glycogens by surface plasmon resonance. The results indicated that the carbohydrate-binding properties toward NSGs of ESG1A9mAb and IV58B6 were similar, but markedly differed for ESGs and EDGs. ESG1A9mAb showed significant affinity for all the ESGs and NSGs tested, whereas IV58B6 had only slight affinity for ESGs, although the affinities were increased when the ESGs were enzymatically digested. This information should be helpful for the design of both in vitro and in vivo immunological assays. (C) 2012 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.carres.2011.12.029

    Web of Science

    PubMed

    researchmap

  • Accumulation of orally administered quercetin in brain tissue and its antioxidative effects in rats 査読

    Akari Ishisaka, Satomi Ichikawa, Hiroyuki Sakakibara, Mariusz K. Piskula, Toshiyuki Nakamura, Yoji Kato, Mikiko Ito, Ken-ichi Miyamoto, Akira Tsuji, Yoshichika Kawai, Junji Terao

    FREE RADICAL BIOLOGY AND MEDICINE   51 ( 7 )   1329 - 1336   2011年10月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE INC  

    Quercetin is widely distributed in vegetables and herbs and has been suggested to act as a neuroprotective agent. Here, we demonstrate that quercetin can accumulate enough to exert biological activity in rat brain tissues. Homogenates of perfused rat brain without detectable hemoglobin contaminants were treated with beta-glucuronidase/sulfatase and the released quercetin and its methylated form were analyzed using high-performance liquid chromatography (HPLC) with three different detection methods. Both quercetin and the methylated form were detected in the brain of quercetin-administered rats using HPLC-UV and HPLC with electrochemical detection and were further identified using HPLC-tandem mass spectrometry. Oral administration of quercetin (50 mg/kg body wt) attenuated the increased oxidative stress in the hippocampus and striatum of rats exposed to chronic forced swimming. The possible transport of quercetin derivatives into the brain tissue was reproduced in vitro by using a rat brain capillary endothelial cell line, a model of the blood-brain barrier. These results show that quercetin could be a potent nutrient that can access the brain and protect it from disorders associated with oxidative stress. (C) 2011 Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.freeradbiomed.2011.06.017

    Web of Science

    PubMed

    researchmap

  • Possible Evidence of Contamination by Catechins in Deconjugation Enzymes from Helix pomatia and Abalone entrails 査読

    Toshiyuki Nakamura, Ryohei Tanaka, Hitoshi Ashida

    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY   75 ( 8 )   1506 - 1510   2011年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:TAYLOR & FRANCIS LTD  

    beta-Glucuronidase and sulfatase are the major deconjugating enzymes used in the cleavage of the glucuronate and sulfate moieties, respectively, from certain conjugated food factors including polyphenols. In the present study, we found that compounds having the same molecular weights as catechins were present in Helix pomatia- and/or Abalone entrails-derived beta-glucuronidase and sulfatase by liquid chromatography tandem mass spectrometry (LC-MS/MS) with multiple reaction monitoring methods. On the other hand, the same molecular weights as catechins were undetectable in Escherichia coli-derived beta-glucuronidase and Aerobacter aerogenes-derived sulfatase. By high performance liquid chromatography, enzyme-derived catechins were not detected because of approximately 1,000-fold lower sensitivity as compared to LC-MS/MS. These results suggest that the catechins in these enzymes might be attributed to the diets of the organisms as the enzyme sources.

    DOI: 10.1271/bbb.110210

    Web of Science

    PubMed

    researchmap

  • alpha-Oligoglucosylation of a sugar moiety enhances the bioavailability of quercetin glucosides in humans 査読

    Kaeko Murota, Namiko Matsuda, Yasuaki Kashino, Yutaka Fujikura, Toshiyuki Nakamura, Yoji Kato, Ryosuke Shimizu, Syuji Okuyama, Hisashi Tanaka, Takatoshi Koda, Keiko Sekido, Junji Terao

    ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS   501 ( 1 )   91 - 97   2010年9月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE INC  

    Dietary intake of quercetin is suggested to be potentially beneficial for the prevention of various diseases. We examined the effect of alpha-oligoglucosylation of the sugar moiety of quercetin monoglucoside on its bioavailability in humans. Enzymatically modified isoquercitrin (EMIQ) was prepared by enzymatic deglycosylation and the subsequent of alpha-oligoglucosylation of quercetin 3-O-beta-rutinode (rutin). The plasma level of quercetin metabolites was instantly increased by oral intake of EMIQ and its absorption efficiency was significantly higher than that of isoquercitrin (quercetin 3-O-beta-glucoside; Q3G), and rutin. The Profile of plasma quercetin metabolites after EMIQ consumption did not differ from that after Q3G consumption. The apparent log P of EMIQ indicated that EMIQ is more hydrophilic than Q3G but less than quercetin 3,4'-O-beta-diglucoside. These data indicated that enzymatic alpha-oligoglucosylation to the sugar moiety is effective for enhancing the bioavailability of quercetin glucosides in humans. (C) 2010 Published by Elsevier Inc.

    DOI: 10.1016/j.abb.2010.06.036

    Web of Science

    PubMed

    researchmap

  • Immunochemical Detection of Food-Derived Isothiocyanate as a Lysine Conjugate 査読

    Toshiyuki Nakamura, Noritoshi Kitamoto, Toshihiko Osawa, Yoji Kato

    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY   74 ( 3 )   536 - 540   2010年3月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:TAYLOR & FRANCIS LTD  

    In a previous study we prepared monoclonal antibody against allyl isothiocyanate (AITC)-modified lysine (Lys), and found that AITC reacted with Lys under physiological conditions in vitro (T. Nakamura et al., Chem. Res. Toxicol., 22, 536-542 (2009)). In the present study, antibodies against benzyl isothiocyanate (ITC), 6-methylsulfinylhexyl ITC and phenethyl ITC modified protein were prepared, and the respective monoclonal antibodies, B6C9, 6MS3D10, and PE3A10 were obtained. These antibodies were applied to ITC detection in food using shredded Wasabia japonica (wasabi) and ground Carica papaya (papaya) seed by trapping ITC with biotin-labeled bovine serum albumin. ITC formation from the wasabi and papaya seed samples was confirmed using the antibodies in a dose-dependent manner. These antibodies might be applicable in identifying food-derived ITC.

    DOI: 10.1271/bbb.90728

    Web of Science

    PubMed

    researchmap

  • Covalent Modification of Lysine Residues by Allyl Isothiocyanate in Physiological Conditions: Plausible Transformation of Isothiocyanate from Thiol to Amine 査読

    Toshiyuki Nakamura, Yoshichika Kawai, Noritoshi Kitamoto, Toshihiko Osawa, Yoji Kato

    CHEMICAL RESEARCH IN TOXICOLOGY   22 ( 3 )   536 - 542   2009年3月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER CHEMICAL SOC  

    We investigated the reactivity of allyl isothiocyanate (AITC) with amino groups under physiological conditions. First, the chemical reaction of AITC with bovine serum albumin (BSA) was investigated. When BSA was incubated with AITC in a phosphate buffer (pH 7.4), the loss of Lys residues was observed. Second, the Lys residue N(alpha)-benzoyl-glycyl-L-lysine (BGK) was reacted with AITC in the buffer, and a novel peak was detected using high performance liquid chromatography (HPLC). The peak was purified and identified as AITC-modified BGK with a N(epsilon)-thiocarbamoyl linkage. However, a thiol residue is known to be a predominant target of an isothiocyanate (ITC). Although AITC may react with a thiol moiety in vivo, a thiocarbamoyl linkage between ITC and thiol is unstable, and an AITC molecule may be regenerated. To prove the plausible transformation of ITC from thiol to amine, synthetic AITC-conjugated N(alpha)-acetyl-L-cysteine (NAC) was incubated with BGK at 37 degrees C in physiological buffer, and the generation of AITC-Lys was analyzed. The loss of the AITC-NAC adduct corresponded to the formation of the AITC-BGK adduct. Furthermore, using a novel monoclonal antibody (A4C7mAb) specific for AITC-Lys, we found that the AITC-Lys residue was generated from the reaction between AITC-NAC and BSA. Although AITC preferentially reacts with thiol rather than with Lys, AITC can be liberated from thiols and can then react with amino groups. The ITC-Lys adduct may be a useful marker for ITC target molecules.

    DOI: 10.1021/tx8003906

    Web of Science

    PubMed

    researchmap

  • Quantification of Modified Tyrosines in Healthy and Diabetic Human Urine using Liquid Chromatography/Tandem Mass Spectrometry 査読

    Yoji Kato, Natsuko Dozaki, Toshiyuki Nakamura, Noritoshi Kitamoto, Akihiro Yoshida, Michitaka Naito, Masayasu Kitamura, Toshihiko Osawa

    JOURNAL OF CLINICAL BIOCHEMISTRY AND NUTRITION   44 ( 1 )   67 - 78   2009年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:JOURNAL CLINICAL BIOCHEMISTRY & NUTRITION  

    The quantification of urinary oxidized tyrosines, dityrosine (DiY), nitrotyrosine (NY), bromotyrosine (BrY), and dibromotyrosine (DiBrY), was accomplished by quadruple liquid chromatography-tandem mass spectrometry (LC/MS/MS). The sample was partially purified by solid phase extraction, and was then applied to the LC/MS/MS using multiple-reaction monitoring (MRM) methods. The analysis for the MY quantification was done first. The residual samples were further butylated with n-butanolt/HCI, and the other modified tyrosines were then quantified with isotopic dilution methods. MRM peaks of the modified tyrosines (DiY, NY, BrY, and DiBrY) from human urine were measured and the elution times coincided with the authentic and isotopic standards. The amounts of modified tyrosines in healthy human urine (n = 23) were 8.8 +/- 0.6 (DiY), 1.4 +/- 0.4 (NY), 3.8 +/- 0.3 (BrY), and 0.7 +/- 0.1 (DiBrY) mu mol/mol of creatinine, respectively. A comparison of the modified tyrosines with urinary 8-oxo-deoxyguanosine, pentosidine, and N-epsilon-(hexanoyl)lysine was also performed. Almost all products, except for NY, showed good correlations with each other. The amounts of the modified tyrosines (NY, BrY, and DiBrY) in the diabetic urine were higher than those in the urine from healthy people.

    DOI: 10.3164/jcbn.08-185

    Web of Science

    PubMed

    researchmap

▼全件表示

MISC

  • Difference in antioxidant capacity of rice extracts among rice categories and degree of milling and processing

    Hongyan Wu, Miho Hirooka, Toshiyuki Nakamura, Shintaro Munemasa, Yoshiyuki Murata, Yoshimasa Nakamura

    The 7th International Conference on Food Factors (ICoFF)proceedings   2019年12月