研究者業績

村上 明

ムラカミ アキラ  (Akira Murakami)

基本情報

所属
兵庫県立大学 環境人間学部 教授
学位
博士(農学)

研究者番号
10271412
ORCID ID
 https://orcid.org/0000-0002-5694-2828
J-GLOBAL ID
200901091245390193
researchmap会員ID
5000027763

外部リンク

詳細については以下を参照してください。
https://sftnetts.jimdo.com/myself/


論文

 299
  • Akari Ishisaka, Ryosuke Sugimoto, Haruka Marumo, Tomoki Doi, Kaede Hamada, Misa Fujimoto, Nao Fujiwara, Masao Yamasaki, Akira Murakami
    Mol Nutr Food Res 2023年8月  査読有り責任著者
  • Nao Fujiwara, Rie Mukai, Miyu Nishikawa, Shinichi Ikushiro, Akira Murakami, Akari Ishisaka
    Bioscience, Biotechnology, and Biochemistry 87(4) 442-447 2023年1月20日  査読有り
    ABSTRACT This is the first study that quantified quercetin (QUE) and its 16 metabolites in the breast milk of QUE-fed maternal mice, the plasma and urine of that, and neonatal mice. Interestingly, the QUE aglycone concentration in the milk was much higher than in the plasma of maternal mice, suggesting that QUE may exert biological activity in neonates.
  • Yoichi Sunagawa, Shogo Kawaguchi, Yusuke Miyazaki, Yasufumi Katanasaka, Masafumi Funamoto, Kana Shimizu, Satoshi Shimizu, Hidetoshi Hamabe-Horiike, Maki Komiyama, Kiyoshi Mori, Akira Murakami, Koji Hasegawa, Tatsuya Morimoto
    Phytomedicine 107 154457-154457 2022年10月  査読有り
    BACKGROUND: Auraptene derived from the peel of Citrus hassaku possesses anti-tumor, anti-inflammatory, and neuroprotective activities. Thus, it could be a valuable pharmacological alternative to treat some diseases. However, the therapeutic value of auraptene for heart failure (HF) is unknown. STUDY DESIGN/METHODS: In cultured cardiomyocytes from neonatal rats, the effect of auraptene on phenylephrine-induced hypertrophic responses and peroxisome proliferator-activated receptor-alpha (PPARα)-dependent gene transcriptions. To investigate whether auraptene prevents the development of heart failure after myocardial infarction (MI) in vivo, Sprague-Dawley rats with moderate MI (fractional shortening < 40%) were randomly assigned for treatment with low- or high-dose auraptene (5 or 50 mg/kg/day, respectively) or vehicle for 6 weeks. The effects of auraptene were evaluated by echocardiography, histological analysis, and the measurement of mRNA levels of hypertrophy, fibrosis, and PPARα-associated genes. RESULTS: In cultured cardiomyocytes, auraptene repressed phenylephrine-induced hypertrophic responses, such as increases in cell size and activities of atrial natriuretic factor and endothelin-1 promoters. Auraptene induced PPARα-dependent gene activation by enhancing cardiomyocyte peroxisome proliferator-responsive element reporter activity. The inhibition of PPARα abrogated the protective effect of auraptene on phenylephrine-induced hypertrophic responses. In rats with MI, auraptene significantly improved MI-induced systolic dysfunction and increased posterior wall thickness compared to the vehicle. Auraptene treatment also suppressed MI-induced increases in myocardial cell diameter, perivascular fibrosis, and expression of hypertrophy and fibrosis response markers at the mRNA level compared with vehicle treatment. MI-induced decreases in the expression of PPARα-dependent genes were improved by auraptene treatment. CONCLUSIONS: Auraptene has beneficial effects on MI-induced cardiac hypertrophy and left ventricular systolic dysfunction in rats, at least partly due to PPARα activation. Further clinical studies are required to evaluate the efficacy of auraptene in patients with HF.
  • Murakami, A.
    Current Opinion in Toxicology 30 2022年4月  査読有り招待有り筆頭著者最終著者責任著者
  • 村上 明
    日本調理科学会誌 55(1) 54-56 2022年2月  査読有り招待有り筆頭著者最終著者責任著者
  • Nurmila Sari, Yasufumi Katanasaka, Yuga Sugiyama, Yoichi Sunagawa, Yusuke Miyazaki, Masafumi Funamoto, Satoshi Shimizu, Kana Shimizu, Akira Murakami, Kiyoshi Mori, Hiromichi Wada, Koji Hasegawa, Tatsuya Morimoto
    Phytomedicine 92 153744-153744 2021年11月  査読有り
    BACKGROUND: Cardiac hypertrophy and fibrosis are hallmarks of cardiac remodeling and are involved functionally in the development of heart failure (HF). However, it is unknown whether Zerumbone (Zer) prevents left ventricular (LV) systolic dysfunction by inhibiting cardiac hypertrophy and fibrosis. PURPOSE: This study investigated the effect of Zer on cardiac hypertrophy and fibrosis in vitro and in vivo. STUDY DESIGN/METHODS: In primary cultured cardiac cells from neonatal rats, the effect of Zer on phenylephrine (PE)-induced hypertrophic responses and transforming growth factor beta (TGF-β)-induced fibrotic responses was observed. To determine whether Zer prevents the development of pressure overload-induced HF in vivo, a transverse aortic constriction (TAC) mouse model was utilized. Cardiac function was evaluated by echocardiography. The changes of cardiomyocyte surface area were observed using immunofluorescence staining and histological analysis (HE and WGA staining). Collagen synthesis and fibrosis formation were measured by scintillation counter and picrosirius staining, respectively. The total mRNA levels of genes associated with hypertrophy (ANF and BNP) and fibrosis (Postn and α-SMA) were measured by qRT-PCR. The protein expressions (Akt and α-SMA) were assessed by western blotting. RESULTS: Zer significantly suppressed PE-induced increase in cell size, mRNA levels of ANF and BNP, and Akt phosphorylation in cardiomyocytes. The TGF-β-induced increase in proline incorporation, mRNA levels of Postn and α-SMA, and protein expression of α-SMA were decreased by Zer in cultured cardiac fibroblasts. In the TAC male C57BL/6 mice, echocardiography results demonstrated that Zer improved cardiac function by increasing LV fractional shortening and reducing LV wall thickness compared with the vehicle group. ZER significantly reduced the level of phosphorylated Akt both in cultured cardiomyocytes treated with PE and in the hearts of TAC. Finally, Zer inhibited the pressure overload-induced cardiac hypertrophy and cardiac fibrosis. CONCLUSION: Zer ameliorates pressure overload-induced LV dysfunction, at least in part by suppressing both cardiac hypertrophy and fibrosis.
  • Naoko Suga, Akira Murakami, Hideyuki Arimitsu, Toshiyuki Nakamura, Yoshimasa Nakamura, Yoji Kato
    Journal of Clinical Biochemistry and Nutrition 69(1) 20-27 2021年  査読有り
    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.
  • Naoko Suga, Akira Murakami, Hideyuki Arimitsu, Kazuya Shiogama, Sarasa Tanaka, Mikiko Ito, Yoji Kato
    Journal of Clinical Biochemistry and Nutrition 69(1) 61-67 2021年  査読有り
    Inflammatory bowel diseases, including Crohn’s disease and ulcerative colitis, are chronic inflammatory disorders associated with oxidative stress. The intestines produce 5-hydroxytryptamine that may negatively affect disease state under inflammatory conditions when overproduced. 5-Hydroxytryptamine is a substrate for myeloperoxidase and is converted into reactive tryptamine-4,5-dione. Here, an experimental colitis model was established through oral administration of 5% dextran sulfate sodium to ICR mice for 7 days. Furthermore, the formation of tryptamine-4,5-dione in the colorectal mucosa/submucosa and colorectal tissue was analyzed by chemical and immunochemical methodologies. First, free tryptamine-4,5-dione in the homogenate was chemically trapped by o-phenylenediamine and analyzed as the stable phenazine derivative. Tryptamine-4,5-dione localization as adducted proteins in the colorectal tissue was immunohistochemically confirmed, and as demonstrated by both methods, this resulted in the significant increase of tryptamine-4,5-dione in dextran sulfate sodium-challenged mice compared with control mice. Immunohistochemical staining confirmed tryptamine-4,5-dione-positive staining at the myeloperoxidase accumulation site in dextran sulfate sodium-challenged mice colorectal tissue. The tryptamine-4,5-dione locus in the mice was partly matched with that of a specific marker for myeloperoxidase, halogenated tyrosine. Overall, the results possibly indicate that tryptamine-4,5-dione is generated by neutrophil myeloperoxidase in inflammatory tissue and may contribute to the development of inflammatory bowel disease.
  • Suihara, S., Ishisaka, A., Murakami, A.
    Bioscience, Biotechnology and Biochemistry 85(2) 2021年  査読有り筆頭著者
  • Murakami, A.
    Current Pharmacology Reports 6(6) 2020年8月  査読有り筆頭著者責任著者
  • Toshiyuki Nakamura, Miho Hirakawa, Yoshimasa Nakamura, Akari Ishisaka, Noritoshi Kitamoto, Akira Murakami, Yoji Kato
    Chemical research in toxicology 32(4) 638-644 2019年4月15日  査読有り
    Benzyl isothiocyanate (BITC), a dietary isothiocyanate (ITC) derived from cruciferous vegetables, has anticancer properties. It is believed that the ITC moiety (-N═C═S) that reacts predominantly with thiol compounds plays a central role in triggering the activities resulting from these properties. Recent studies have demonstrated that ITCs also covalently modify amino moieties in a protein. In this study, we examined the chemical reaction between BITC and the aminophospholipid, phosphatidylethanolamine (PE), in the cell membrane or lipoprotein particle. To detect the BITC-modified PE, the bond between ethanolamine (EA) and phosphatidic acid in PE was cleaved using phospholipase D to form the BITC-EA adduct, which was then measured. BITC-EA was detected from the BITC-treated unilamellar liposome and low-density lipoprotein even with only a few micromoles of BITC treatment, suggesting that BITC might react with not only a thiol/amino group of a protein but also an amino moiety of an aminophospholipid. Moreover, after incorporating BITC-PE included in the liposomes into the cultured cells or after direct exposure of BITC to the cells, free BITC-EA was excreted and accumulated in the medium in a time-dependent manner. It indicates that an intracellular enzyme catalyzes the cleavage of BITC-PE to produce BITC-EA. Because the ITC-amine adduct is stable, the ITC-EA adduct could be a promising indicator of ITC exposure in vivo.
  • 江部 綾華, 砂川 陽一, 刀坂 泰史, 宮崎 雄輔, 船本 雅文, 清水 果奈, Nurmila Sari, 清水 聡史, 村上 明, 和田 啓道, 島津 章, 長谷川 浩二, 森本 達也
    日本栄養・食糧学会大会講演要旨集 73回 235-235 2019年4月  
  • Valentine, C., Ohnishi, K., Irie, K., Murakami, A.
    Journal of Clinical Biochemistry and Nutrition 65(2) 2019年  査読有り筆頭著者
  • 佐々木 華, 砂川 陽一, 鈴木 杏奈, 船本 雅文, 清水 果奈, 刀坂 泰史, 宮崎 雄輔, 清水 聡史, Nurmila Sari, 村上 明, 浅川 倫宏, 菅 敏幸, 和田 啓道, 島津 章, 長谷川 浩二, 森本 達也
    日本薬学会年会要旨集 138年会(3) 75-75 2018年3月  
  • Akira Murakami
    Journal of Clinical Biochemistry and Nutrition 62(2) 115-123 2018年3月1日  査読有り筆頭著者責任著者
    In a variety of experimental models, dietary phytochemicals have been demonstrated to exhibit pronounced and versatile bio-activities. Importantly, the possibility of such phytochemicals for human application has been supported in part by epidemiological surveys, which have demonstrated that frequent ingestion of vegetables and fruits containing abundant phytochemicals lowers the risk of onset of various diseases. However, the action mechanisms underlying those dietary phytochemical activities remain to be fully elucidated. For example, even though the anti-oxidant effects of natural polyphenols have long received widespread attention from food scientists, their roles in and contribution to those bioactivities remain controversial because of their poor bioavailability, resulting in extremely low concentrations in the bloodstream. Meanwhile, another important question is why phytochemicals have beneficial effects for animals, including humans, since they are biosynthesized by plants as compounds necessary for adaptation to environmental stress. In regard to that fundamental question, we recently reported novel and unique mechanisms of action of zerumbone, a sesquiterpene with anti-inflammatory and chemopreventive properties. This agent was found to partially exhibit bioactivity through its non-specific interactions with cellular proteins. More strikingly, a non-specific protein binding action of zerumbone was revealed to partially contribute to its anti-inflammatory functions via activation of heat shock factor 1. The present review article highlights and introduces our recent findings regarding the proteo-stress-mediated mechanisms of this phytochemical, along with the concept of hormesis.
  • 佐々木 華, 砂川 陽一, 小川原 慎太郎, 鈴木 杏奈, 櫻井 涼賀, 船本 雅文, 刀坂 泰史, 村上 明, 稲垣 暢也, 今泉 厚, 和田 啓道, 長谷川 浩二, 森本 達也
    日本抗加齢医学会総会プログラム・抄録集 17回 190-190 2017年6月  
  • 藪田 亜沙美, 砂川 陽一, 小川原 慎太郎, 鈴木 杏奈, 櫻井 涼賀, 船本 雅文, 刀坂 泰史, 村上 明, 稲垣 暢也, 今泉 厚, 和田 啓道, 長谷川 浩二, 森本 達也
    日本抗加齢医学会総会プログラム・抄録集 17回 190-190 2017年6月  
  • 佐々木 華, 砂川 陽一, 小川原 慎太郎, 鈴木 杏奈, 船本 雅文, 刀坂 泰史, 村上 明, 和田 啓道, 長谷川 浩二, 森本 達也
    日本薬学会年会要旨集 137年会(3) 73-73 2017年3月  
  • Naoko Suga, Akira Murakami, Yoshimasa Nakamura, Akari Ishisaka, Noritoshi Kitamoto, Mikiko Ito, Yoji Kato
    FREE RADICAL RESEARCH 51(5) 545-553 2017年  査読有り
    Serotonin (5-hydroxytryptamine) is a putative substrate for myeloperoxidase, which may convert it into the reactive quinone tryptamine-4,5-dione (TD). In this study, we found that the viability of human SH-SY5Y neuroblastoma cells treated with 25 mu M TD was increased to approximately 117%. On the other hand, the cell viability was significantly decreased by exposure to TD (150-200 mu M), with an increase in intracellular reactive oxygen species (ROS). Interestingly, pretreatment of SH-SY5Y cells with 100 mu M TD prevented cell death and suppressed intracellular ROS generation evoked by the addition of hydrogen peroxide (H2O2). Expression of the phase-II antioxidant enzyme NAD(P)H: quinone oxidoreductase 1 and haem oxygenase 1 were upregulated by TD at a concentration of 50-100 mu M. Nuclear factor erythroid 2-related factor 2 (Nrf2), the regulator of these enzyme, was translocated from the cytosol to the nucleus by 100 mu M TD. In summary, moderate concentrations of TD may increase the self-defence capacity of neuronal cells against oxidative stress.
  • Yoko Igarashi, Kohta Ohnishi, Kazuhiro Irie, Akira Murakami
    PLOS ONE 11(8) e0161282 2016年8月  査読有り責任著者
    Zerumbone is a sesquiterpene present in Zinger zerumbet. Many studies have demonstrated its marked anti-inflammatory and anti-carcinogenesis activities. Recently, we showed that zerumbone binds to numerous proteins with scant selectivity and induces the expression of heat shock proteins (HSPs) in hepatocytes. To dampen proteo-toxic stress, organisms have a stress-responsive molecular machinery, known as heat shock response. Heat shock factor 1 (HSF1) plays a key role in this protein quality control system by promoting activation of HSPs. In this study, we investigated whether zerumbone-induced HSF1 activation contributes to its anti-inflammatory functions in stimulated macrophages. Our findings showed that zerumbone increased cellular protein aggregates and promoted nuclear translocation of HSF1 for HSP expression. Interestingly, HSF1 down-regulation attenuated the suppressive effects of zerumbone on mRNA and protein expressions of pro-inflammatory genes, including inducible nitric oxide synthase and interlukin-1 beta. These results suggest that proteo-stress induced by zerumbone activates HSF1 for exhibiting its anti-inflammatory functions.
  • Sunagawa Yoichi, Ogawahara Shintaro, Funamoto Masafumi, Sakurai Ryoga, Hieda Kehima, Katanasaka Yasufumi, Asakawa Tomohiro, Kan Toshiyuki, Murakami Akira, Wada Hiromichi, Murakami Akira, Hasegawa Koji, Morimoto Tatsuya
    CIRCULATION 132 2015年11月10日  査読有り
  • Akira Murakami, Atsushi Nesumi, Mari Maeda-Yamamoto, Hidekazu Yamaguchi, Koji Yashima, Masahiro Miura, Tsuyoshi Nakano, Kazunori Nekoshima
    JOURNAL OF FOOD AND DRUG ANALYSIS 23(3) 407-416 2015年9月  査読有り筆頭著者責任著者
    Sunrouge is an anthocyanin-rich, new tea cultivar that contains similar levels of catechins as Yabukita, the most popular tea cultivar consumed in Japan. Interestingly, Sunrouge preparations have previously been shown to have more pronounced acetylcholinesterase inhibitory and anticolitis activities than those of Yabukita. In this study, we examined their effects on expressions of self-defensive molecules, including heat shock proteins (HSPs), which are molecular chaperones involved in homeostasis and longevity. Hot water extract from freeze-dried Sunrouge significantly upregulated messenger RNA (mRNA) expressions of HSP40, HSP70, and HSP32 (heme oxygenase-1), with grades greater than those shown by Yabukita. Oral administration of freeze-dried preparation of Sunrouge to male ICR mice at a dose of 1% in the basal diet for 1 month resulted in marked upregulations of several HSP mRNA expressions in mucosa from the gastrointestinal tract, especially the upper small intestine. Again, its efficacy was remarkably higher than that of Yabukita. Moreover, exposure of Caenorhabditis elegans to Sunrouge conferred thermoresistant phenotype, and also resulted in a significant life-span elongation. Taken together, our results suggest that Sunrouge is a unique and promising tea cultivar for regulating self-defense systems. Copyright (c) 2015, Food and Drug Administration, Taiwan. Published by Elsevier Taiwan LLC. All rights reserved.
  • Akira Murakami
    ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS 557 3-10 2014年9月  査読有り筆頭著者責任著者
    A large number of physiologically functional foods are comprised of plant polyphenols. Their antioxidative activities have been intensively studied for a long period and proposed to be one of the major mechanisms of action accounting for their health promotional and disease preventive effects. Green tea polyphenols (GTPs) are considered to possess marked anti-oxidative properties and versatile beneficial functions, including anti-inflammation and cancer prevention. On the other hand, some investigators, including us, have uncovered their toxicity at high doses presumably due to pro-oxidative properties. For instance, both experimental animal studies and epidemiological surveys have demonstrated that GTPs may cause hepatotoxicity. We also recently showed that diets containing high doses (0.5-1%) of a GTP deteriorated dextran sodium sulfate (DSS)-induced intestinal inflammation and carcinogenesis. In addition, colitis mode mice fed a 1% GTP exhibited symptoms of nephrotoxicity, as indicated by marked elevation of serum creatinine level. This diet also increased thiobarbituric acid-reactive substances, a reliable marker of oxidative damage, in both kidneys and livers even in normal mice, while the expression levels of antioxidant enzymes and heat shock proteins (HSPs) were diminished in colitis and normal mice. Intriguingly, GTPs at 0.01% and 0.1% showed hepato-protective activities, i.e., they significantly suppressed DSS-increased serum aspartate aminotransferase and alanine aminotransferase levels. Moreover, those diets remarkably restored DSS-down-regulated expressions of heme oxygenase-1 and HSP70 in livers and kidneys. Taken together, while low and medium doses of GTPs are beneficial in colitis model mice, unwanted side-effects occasionally emerge with high doses. This dose-dependent functionality and toxicity of GTPs are in accordance with the concept of hormesis, in which mild, but not severe, stress activates defense systems for adaptation and survival. (C) 2014 Elsevier Inc. All rights reserved.
  • Makoto Edagawa, Junya Kawauchi, Manabu Hirata, Hiroto Goshima, Makoto Inoue, Tatsuro Okamoto, Akira Murakami, Yoshihiko Maehara, Shigetaka Kitajima
    JOURNAL OF BIOLOGICAL CHEMISTRY 289(31) 21544-21561 2014年8月  査読有り
    Death receptor 5 (DR5) is a death domain-containing transmembrane receptor that triggers cell death upon binding to its ligand, TNF-related apoptosis-inducing ligand (TRAIL), and a combination of TRAIL and agents that increase the expression of DR5 is expected to be a novel anticancer therapy. In this report, we demonstrate that the stress response gene ATF3 is required for endoplasmic reticulum stress-mediated DR5 induction upon zerumbone (ZER) and celecoxib (CCB) in human p53-deficient colorectal cancer cells. Both agents activated PERK-eIF2 alpha kinases and induced the expression of activating transcription factor 4 (ATF4)-CCAAT enhancer-binding protein (C/EBP) homologous protein, which were remarkably suppressed by reactive oxygen species scavengers. In the absence of ATF3, the induction of DR5 mRNA and protein was abrogated significantly, and this was associated with reduced cell death by cotreatment of TRAIL with ZER or CCB. By contrast, exogenous expression of ATF3 caused a more rapid and elevated expression of DR5, resulting in enhanced sensitivity to apoptotic cell death by TRAIL/ZER or TRAIL/CCB. A reporter assay demonstrated that at least two ATF/cAMP response element motifs as well as C/EBP homologous protein motif at the proximal region of the human DR5 gene promoter were required for ZER-induced DR5 gene transcription. Taken together, our results provide novel insights into the role of ATF3 as an essential transcription factor for p53-independent DR5 induction upon both ZER and CCB treatment, and this may be a useful biomarker for TRAIL-based anticancer therapy.
  • Murakami, A.
    Cancer and Inflammation Mechanisms: Chemical, Biological, and Clinical Aspects 2014年  
  • Takashi Kitayama, Maki Nakahira, Kae Yamasaki, Hiromi Inoue, Chika Imada, Yuji Yonekura, Masataka Awata, Hikaru Takaya, Yasushi Kawai, Kohta Ohnishi, Akira Murakami
    TETRAHEDRON 69(47) 10152-10160 2013年11月  査読有り
    Zerumbone 1, having powerful latent reactivity and containing two conjugated double bonds and a double conjugated carbonyl group is the major component of the essential oil of wild ginger, Zingiber zerumbet Smith. The conjugation system plays an important role in the expression of biological activity. N-Bromosuccinimide (NBS) reaction of 1 gave high reactive intermediate 2 with an exo-methylene group, which was obtained from 1 quantitatively. Treatment of 2 with nucleophiles gave various zerumbonependant derivatives, including C-H, C-O, C-N, and C-C bond formation, maintaining the conjugation system through S(N)2'-type reaction. Almost all zerumbone-pendant derivatives showed a good value of IC50 against the suppressive effect of NO generation. Among them, amine derivative 5, binding with 2 mol of zerumbone, showed the strongest activity (IC50: 0.24 mu M). (C) 2013 Elsevier Ltd. All rights reserved.
  • Takashi Kitayama, Maki Nakahira, Kae Yamasaki, Hiromi Inoue, Chika Imada, Yuji Yonekura, Masataka Awata, Hikaru Takaya, Yasushi Kawai, Kohta Ohnishi, Akira Murakami
    TETRAHEDRON 69(47) 10152-10160 2013年11月  査読有り
    Zerumbone 1, having powerful latent reactivity and containing two conjugated double bonds and a double conjugated carbonyl group is the major component of the essential oil of wild ginger, Zingiber zerumbet Smith. The conjugation system plays an important role in the expression of biological activity. N-Bromosuccinimide (NBS) reaction of 1 gave high reactive intermediate 2 with an exo-methylene group, which was obtained from 1 quantitatively. Treatment of 2 with nucleophiles gave various zerumbonependant derivatives, including C-H, C-O, C-N, and C-C bond formation, maintaining the conjugation system through S(N)2'-type reaction. Almost all zerumbone-pendant derivatives showed a good value of IC50 against the suppressive effect of NO generation. Among them, amine derivative 5, binding with 2 mol of zerumbone, showed the strongest activity (IC50: 0.24 mu M). (C) 2013 Elsevier Ltd. All rights reserved.
  • Ohnishi, K., Irie, K., Murakami, A.
    Functional Foods in Health and Disease 3(10) 400-415 2013年10月  査読有り責任著者
  • 大西康太, 入江一浩, 村上明
    バイオサイエンスとインダストリー 71(5) 400-406 2013年9月  招待有り責任著者
  • Hirofumi Inoue, Mari Maeda-Yamamoto, Atsushi Nesumi, Takuji Tanaka, Akira Murakami
    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY 77(6) 1223-1228 2013年6月  査読有り責任著者
    Our previous study indicated that a diet containing a high dose (1%) of green tea polyphenols (GTPs) disrupted liver and kidney function via a reduction in antioxidant enzyme and heat shock protein (HSP) levels in both colitis and non-treated ICR mice. In the present study, we assessed the effects of 0.01%, 0.1%, and 1% dietary GTPs on liver and kidney physiological functioning in dextran sulfate sodium (DSS)-exposed and normal mice. GTPs at 0.01% and 0.1% significantly suppressed DSS-increased serum aspartate 2-oxoglutarate aminotransferase (AST) and alanine aminotransferase (ALT) levels. In contrast, GTPs at 1% increased kidney weight, serum creatinine levels, and thiobarbituric acid-reactive substances (TBARs) in both the kidney and the liver in normal mice, as compared with DSS-exposed mice. GTPs at 0.01% and 0.1% remarkably upregulated the expression of heme oxygenase-1 (HO-1) and heat shock protein 70 (HSP70) mRNA in the liver and kidney of mice exposed to DSS, whereas GTPs at 1% abolished it. Our results indicate that low and medium doses of GTPs have beneficial effects on DSS-induced hepatotoxicity and nephrotoxicity via upregulation of self-protective enzymes, while these effects disappeared at a high dose.
  • Bokyung Sung, Sahdeo Prasad, Vivek R. Yadav, Subash C. Gupta, Simone Reuter, Norio Yamamoto, Akira Murakami, Bharat B. Aggarwal
    PLoS ONE 8(5) e64118 2013年5月17日  査読有り
    Bone loss/resorption or osteoporosis is a disease that is accelerated with aging and age-associated chronic diseases such as cancer. Bone loss has been linked with human multiple myeloma, breast cancer, and prostate cancer and is usually treated with bisphosphonates, and recently approved denosumab, an antibody against receptor activator of NF-κB ligand (RANKL). Because of the numerous side effects of the currently available drugs, the search continues for safe and effective therapies for bone loss. RANKL, a member of the TNF superfamily, has emerged as a major mediator of bone loss via activation of osteoclastogenesis. We have identified cardamonin, a chalcone isolated from Alpinia katsumadai Hayata that can affect osteoclastogenesis through modulation of RANKL. We found that treatment of monocytes with cardamonin suppressed RANKL-induced NF-κB activation and this suppression correlated with inhibition of IκBα kinase and of phosphorylation and degradation of IκBα, an inhibitor of NF-κB. Furthermore, cardamonin also downregulated RANKL-induced phosphorylation of MAPK including ERK and p38 MAPK. Cardamonin suppressed the RANKL-induced differentiation of monocytes to osteoclasts in a dose-dependent and time-dependent manner. We also found that an inhibitor of NF-κB essential modulator (NEMO) blocked RANKL-induced osteoclastogenesis, indicating a direct link with NF-κB. Finally, osteoclastogenesis induced by human breast cancer cells or human multiple myeloma cells were completely suppressed by cardamonin. Collectively, our results indicate that cardamonin suppresses osteoclastogenesis induced by RANKL and tumor cells by suppressing activation of the NF-κB and MAPK pathway. © 2013 Sung et al.
  • Akira Murakami
    JOURNAL OF CLINICAL BIOCHEMISTRY AND NUTRITION 52(3) 215-227 2013年5月  査読有り筆頭著者責任著者
    There is compelling evidence showing that dietary phytochemicals have exhibited pronounced bioactivities in a number of experimental models. In addition, a variety of epidemiological surveys have demonstrated that frequent ingestion of vegetables and fruits, which contain abundant phytochemicals, lowers the risk of onset of some diseases. However, the action mechanisms by which dietary phytochemicals show bioactivity remain to be fully elucidated and a fundamental question is why this class of chemicals has great potential for regulating health. Meanwhile, maintenance and repair of biological proteins by molecular chaperones, such as heat shock proteins, and clearance of abnormal proteins by the ubiquitin-proteasome system and autophagy play central roles in health, some disease prevention, and longevity. Interestingly, several recent studies have revealed that phytochemicals, including curcumin (yellow pigment in turmeric), resveratrol (phytoalexin in grapes), quercetin (general flavonol in onions and others), and isothiocyanates (preferentially present in cruciferous vegetables, such as broccoli and cabbage), are remarkable regulators of protein quality control systems, suggesting that their physiological and biological functions are exerted, at least in part, through activation of such unique mechanisms. This review article highlights recent findings regarding the effects of representative phytochemicals on protein quality control systems and their possible molecular mechanisms.
  • Hiroaki Kamachi, Keisuke Tanaka, Ryo C. Yanagita, Akira Murakami, Kazuma Murakami, Harukuni Tokuda, Nobutaka Suzuki, Yu Nakagawa, Kazuhiro Irie
    BIOORGANIC & MEDICINAL CHEMISTRY 21(10) 2695-2702 2013年5月  査読有り
    We have recently developed a simplified analog of aplysiatoxin (aplog-1) as an activator of protein kinase C (PKC) with anti-proliferative activity like bryostain 1. To identify sites in aplog-1 that could be readily modified to optimize therapeutic performance and to develop a molecular probe for examining the analog's mode of action, substituent effects on the phenol ring were systematically examined. Whereas hydrophilic acetamido derivatives were less active than aplog-1 in inhibiting cancer cell growth and binding to PKCS, introduction of hydrophobic bromine and iodine atoms enhanced both biological activities. The anti-proliferative activity was found to correlate closely with molecular hydrophobicity, and maximal activity was observed at a log P value of 4.0-4.5. On the other hand, an induction test with Epstein-Barr virus early antigen demonstrated that these derivatives have less tumor-promoting activity in vitro than aplog-1 regardless of the hydrophobicity of their substituents. These results would facilitate rapid preparation of molecular probes to examine the mechanism of the unique biological activities of aplog-1. (C) 2013 Elsevier Ltd. All rights reserved.
  • Kohta Ohnishi, Shinya Ohkura, Erina Nakahata, Akari Ishisaka, Yoshichika Kawai, Junji Terao, Taiki Mori, Takeshi Ishii, Tsutomu Nakayama, Noriyuki Kioka, Shinya Matsumoto, Yasutaka Ikeda, Minoru Akiyama, Kazuhiro Irie, Akira Murakami
    PLOS ONE 8(3) e58641 2013年3月  査読有り責任著者
    Accumulated evidence shows that some phytochemicals provide beneficial effects for human health. Recently, a number of mechanistic studies have revealed that direct interactions between phytochemicals and functional proteins play significant roles in exhibiting their bioactivities. However, their binding selectivities to biological molecules are considered to be lower due to their small and simple structures. In this study, we found that zerumbone, a bioactive sesquiterpene, binds to numerous proteins with little selectivity. Similar to heat-denatured proteins, zerumbone-modified proteins were recognized by heat shock protein 90, a constitutive molecular chaperone, leading to heat shock factor 1-dependent heat shock protein induction in hepa1c1c7 mouse hepatoma cells. Furthermore, oral administration of this phytochemical up-regulated heat shock protein expressions in the livers of Sprague-Dawley rats. Interestingly, pretreatment with zerumbone conferred a thermoresistant phenotype to hepa1c1c7 cells as well as to the nematode Caenorhabditis elegans. It is also important to note that several phytochemicals with higher hydrophobicity or electrophilicity, including phenethyl isothiocyanate and curcumin, markedly induced heat shock proteins, whereas most of the tested nutrients did not. These results suggest that non-specific protein modifications by xenobiotic phytochemicals cause mild proteostress, thereby inducing heat shock response and leading to potentiation of protein quality control systems. We considered these bioactivities to be xenohormesis, an adaptation mechanism against xenobiotic chemical stresses. Heat shock response by phytochemicals may be a fundamental mechanism underlying their various bioactivities.
  • Kohta Ohnishi, Erina Nakahata, Kazuhiro Irie, Akira Murakami
    Biochemical and Biophysical Research Communications 430(2) 616-622 2013年1月11日  査読有り責任著者
    Zerumbone, a sesquiterpene present in Zingiber zerumbet Smith, has been implicated as a promising chemopreventive agent. Interestingly, a number of studies have revealed that its potent bioactivities are dependent on the electrophilic moiety of its α,β-unsaturated carbonyl group, while our recent findings showed its chemical potential for binding to cellular proteins through a Michael reaction. In the present study, modifications of proteins by zerumbone led to their insolubilization in vitro. In living cell models, zerumbone induced ubiquitination and aggregation of cellular proteins, which demonstrated its substantial proteo-toxicity. On the other hand, it was also revealed that zerumbone possesses potential for activating intracellular proteolysis mechanisms of the ubiquitin-proteasome system and autophagy. Furthermore, it up-regulated expressions of pro-autophagic genes including p62, which is known as a cargo receptor of aggrephagy, the selective autophagic process for protein aggregates. Pretreatment of Hepa1c1c7 cells with zerumbone conferred a phenotype resistant to cytotoxicity and protein modifications by 4-hydroxy-2-nonenal, an endogenous lipid peroxidation product, in a p62-dependent manner. Together, these results suggest that protein modifications by zerumbone cause mild proteo-stress, thereby activating intracellular proteolysis machineries to maintain protein homeostasis. We consider these effects on proteolysis mechanisms to be hormesis, which provides beneficial functions through mild biological stresses. © 2012 Elsevier Inc.
  • Murakami, A., Furukawa, I., Miyamoto, S., Tanaka, T., Ohigashi, H.
    BioFactors 39(2) 2013年  査読有り
  • Murakami, A.
    Tea in Health and Disease Prevention 2013年  
  • Murakami, A.
    Polyphenols in Human Health and Disease 2 2013年  
  • Yuki Ikeda, Ryoichi Yamaji, Kazuhiro Irie, Noriyuki Kioka, Akira Murakami
    ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS 528(2) 141-147 2012年12月  査読有り責任著者
    Cyclooxygenase (COX)-2 is an inducible inflammatory protein whose expression is partially regulated at the post-transcriptional level. We investigated whether glyceraldehyde-3-phosphate dehydrogenase (GAPDH) binds to the AU-rich element (ARE) of COX-2 mRNA for its degradation. Knockdown of GAPDH in hepa1c1c7 cells significantly enhanced COX-2 expressions. Recombinant GAPDH bound to the COX-2 ARE within the first 60 nucleotides of the 3'-UTR via the NAD(+) binding domain. Interestingly, a C151S GAPDH mutant retained binding activity. Confocal microscopy observation revealed that LPS exposure reduced the localization of GAPDH in nuclei. Our results indicate that GAPDH negatively regulates COX-2 by binding to its ARE. (C) 2012 Elsevier Inc. All rights reserved.
  • Anuradha Sehrawat, Julie A. Arlotti, Akira Murakami, Shivendra V. Singh
    BREAST CANCER RESEARCH AND TREATMENT 136(2) 429-441 2012年11月  査読有り
    The present study was undertaken to determine the anticancer efficacy of zerumbone (ZER), a sesquiterpene from subtropical ginger, against human breast cancer cells in vitro and in vivo. ZER treatment caused a dose-dependent decrease in viability of MCF-7 and MDA-MB-231 human breast cancer cells in association with G(2)/M phase cell cycle arrest and apoptosis induction. ZER-mediated cell cycle arrest was associated with downregulation of cyclin B1, cyclin-dependent kinase 1, Cdc25C, and Cdc25B. Even though ZER treatment caused stabilization of p53 and induction of PUMA, these proteins were dispensable for ZER-induced cell cycle arrest and/or apoptosis. Exposure of MDA-MB-231 and MCF-7 cells to ZER resulted in downregulation of Bcl-2 but its ectopic expression failed to confer protection against ZER-induced apoptosis. On the other hand, the SV40 immortalized mouse embryonic fibroblasts derived from Bax and Bak double knockout mice were significantly more resistant to ZER-induced apoptosis. ZER-treated MDA-MB-231 and MCF-7 cells exhibited a robust activation of both Bax and Bak. In vivo growth of orthotopic MDA-MB-231 xenografts was significantly retarded by ZER administration in association with apoptosis induction and suppression of cell proliferation (Ki-67 expression). These results indicate that ZER causes G(2)/M phase cell cycle arrest and Bax/Bak-mediated apoptosis in human breast cancer cells, and retards growth of MDA-MB-231 xenografts in vivo.
  • Atsushi Nesumi, Akiko Ogino, Katsuyuki Yoshida, Fumiya Taniguchi, Mari Maeda Yamamoto, Junichi Tanaka, Akira Murakami
    JARQ-JAPAN AGRICULTURAL RESEARCH QUARTERLY 46(4) 321-328 2012年10月  査読有り
    'Sunrouge' is an anthocyanin-rich tea cultivar, which was selected from the population derived from the natural crossing of 'Cha Chuukanbohon Nou 6' (C. taliensis X C. sinensis). The anthocyanin content of 'Sunrouge' exceeded that of 'Cha Chuukanbohon Nou 6', which was bred as an anthocyanin-rich tea parental line. However the anthocyanin content of 'Cha Chuukanbohon Nou 6' depends on the plucking period, growth stage and the part of the new shoot. The emergence of the 'Sunrouge' crop is moderately early, as with the Japanese leading cultivar 'Yabukita' (C. sinensis var. sinensis). The 'Sunrouge' tree is of the medium type and has many branches in comparison to typical cultivars. In terms of resistance, it is slightly resistant to anthracnose (Discula theae-sinensis (I. Miyake) Moriwaki & Toy. Sato comb. nov.), highly resistant to gray blight (Pestalotiopsis longiseta (Spegazzini) Dai & Kobayashi) and has relatively low resistance to brown blight (Glomerella cingulata (Stoneman) Spaulding & Schrenk). The survival rate of 'Sunrouge' is lower than 'Yabukita' and the other control cultivars in the cutting propagation. We try to propagate using the photoautotrophic culture method and the propagation of 'Sunrouge' was incident-free. We anticipate its use as a functional food and the material of the natural pigment.
  • Mari Maeda-Yamamoto, Takeshi Saito, Atsushi Nesumi, Yoshiko Tokuda, Kaori Ema, Daiki Honma, Akiko Ogino, Manami Monobe, Akira Murakami, Akira Murakami, Hirofumi Tachibana
    JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 92(11) 2379-2386 2012年8月  査読有り
    BACKGROUND: The purpose of this study was to evaluate the effects of leaf order or crop season on anthocyanins and other chemicals in the anthocyanin-rich tea cultivar Sunrouge (Camellia sinensis x C. taliensis) by using high-performance liquid chromatography, and to study the effect of Sunrouge extract on acetylcholinesterase (AChE) activity in human neuroblastoma SK-N-SH cells. RESULTS: The total anthocyanin content was higher in the third (3.09 mg g-1) than in the second (2.24 mg g-1) or first crop season (1.79 mg g-1). The amount of anthocyanins contained in the stem was high (1.61 mg g-1). In the third crop season, the concentrations of delphinidin-3-O-beta-D-(6-(E)-p-coumaroyl)galactopyranoside (DCGa), cyanidin-3-O-beta-D-(6-(E)-p-coumaroyl)galactopyranoside, delphinidin-3-O-beta-D-galactopyranoside, delphinidin-3-O-beta-D-(6-O-(Z)-p-coumaroyl)galactopyranoside, cyanidin-3-O-beta-D-galactoside, and delphinidin-3-O-beta-D-glucoside were 1.57 mg g-1, 0.52 mg g-1, 0.40 mg g-1, 0.22 mg g-1, 0.14 mg g-1, and 0.11 mg g-1, respectively. DCGa accounted for about 50% of the anthocyanins present. The suppressive effect of Sunrouge water extract on AChE activity in human neuroblastoma SK-N-SH cells was the strongest among the three tea cultivars (Sunrouge, Yabukita and Benifuuki). CONCLUSION: These results suggested that Sunrouge might protect humans from humans from AChE-related diseases by suppressing AChE activity. To obtain sufficient amounts of anthocyanins, catechins and/or caffeine for a functional food material, Sunrouge from the third crop season should be used. Copyright (c) 2012 Society of Chemical Industry
  • Mari Maeda-Yamamoto, Takeshi Saito, Atsushi Nesumi, Yoshiko Tokuda, Kaori Ema, Daiki Honma, Akiko Ogino, Manami Monobe, Akira Murakami, Akira Murakami, Hirofumi Tachibana
    JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 92(11) 2379-2386 2012年8月  査読有り
    BACKGROUND: The purpose of this study was to evaluate the effects of leaf order or crop season on anthocyanins and other chemicals in the anthocyanin-rich tea cultivar Sunrouge (Camellia sinensis x C. taliensis) by using high-performance liquid chromatography, and to study the effect of Sunrouge extract on acetylcholinesterase (AChE) activity in human neuroblastoma SK-N-SH cells. RESULTS: The total anthocyanin content was higher in the third (3.09 mg g-1) than in the second (2.24 mg g-1) or first crop season (1.79 mg g-1). The amount of anthocyanins contained in the stem was high (1.61 mg g-1). In the third crop season, the concentrations of delphinidin-3-O-beta-D-(6-(E)-p-coumaroyl)galactopyranoside (DCGa), cyanidin-3-O-beta-D-(6-(E)-p-coumaroyl)galactopyranoside, delphinidin-3-O-beta-D-galactopyranoside, delphinidin-3-O-beta-D-(6-O-(Z)-p-coumaroyl)galactopyranoside, cyanidin-3-O-beta-D-galactoside, and delphinidin-3-O-beta-D-glucoside were 1.57 mg g-1, 0.52 mg g-1, 0.40 mg g-1, 0.22 mg g-1, 0.14 mg g-1, and 0.11 mg g-1, respectively. DCGa accounted for about 50% of the anthocyanins present. The suppressive effect of Sunrouge water extract on AChE activity in human neuroblastoma SK-N-SH cells was the strongest among the three tea cultivars (Sunrouge, Yabukita and Benifuuki). CONCLUSION: These results suggested that Sunrouge might protect humans from humans from AChE-related diseases by suppressing AChE activity. To obtain sufficient amounts of anthocyanins, catechins and/or caffeine for a functional food material, Sunrouge from the third crop season should be used. Copyright (c) 2012 Society of Chemical Industry
  • Hirotaka Sekiguchi, Fumiyo Takabayashi, Kazuhiro Irie, Akira Murakami
    JOURNAL OF MEDICINAL FOOD 15(7) 658-663 2012年7月  査読有り
    Helicobacter pylori is a major human pathogen that plays central roles in chronic gastritis and gastric cancer. Recently, we reported that auraptene suppressed H. pylori adhesion via expression of CD74, which has been identified as a new receptor for H. pylori urease. In this study, we attempted to clarify the effects of oral feeding of auraptene on H. pylori infection and resultant inflammatory responses in C57BL/6 mice and found that it remarkably attenuated H. pylori colonization and gastritis. Biochemical analyses revealed that auraptene inhibited H. pylori-induced expression and/or production of CD74, macrophage migration inhibitory factor, interleukin-1 beta, and tumor necrosis factor-alpha in gastric mucosa, together with serum macrophage inhibitory protein-2. It is notable that treatment with this coumarin during the pretreatment period was more effective than that during posttreatment. Our results suggest that auraptene is a promising phytochemical for reducing the risk of H. pylori-induced gastritis and carcinogenesis.
  • Akiyama S, Nesumi A, Maeda-Yamamoto M, Uehara M, Murakami A
    Biofactors 38(3) 226-233 2012年5月16日  査読有り
    緑茶ポリフェノール(GTP)は過剰な投与量では、潰瘍性大腸炎モデルマウスの症状を悪化させるが、アントシアニンリッチなGPT投与では、マウスの生存率、大腸長、炎症性サイトカインおよび抗酸化酵素を改善させることを確認した。IF:3.088
  • Hirofumi Inoue, Mari Maeda-Yamamoto, Atsushi Nesumi, Akira Murakami
    NUTRITION RESEARCH 32(5) 357-364 2012年5月  査読有り
    Delphinidin-3-O-galactoside (D3G) is a water-soluble anthocyanin with antioxidant activity. (-)-Epigallocatechin-3-gallate (EGCG) is also known as a powerful antioxidant but concomitantly possesses a prooxidative property. We hypothesized that D3G is capable of protecting the EGCG-induced cytotoxicity and endoplasmic reticulum (ER) stress via inducing self-protective proteins and antioxidant enzymes. (-)-Epigallocatechin-3-gallate (200-500 mu M) dose dependently decreased the viability of hepa1c1c-7 mouse hepatocytes, whereas D3G (50-500 mu M) did not change it. Pretreatment with D3G significantly suppressed EGCG-induced cytotoxicity in a time-dependent manner (0, 6, and 24 hours). (-)-Epigallocatechin-3-gallate drastically decreased heme oxygenase-1 and heat shock protein 70 messenger RNA (mRNA) levels, whereas, pretreatment with D3G markedly attenuated their down-regulations. Delphinidin-3-O-galactoside remarkably decreased EGCG-induced ER stress responses such as C/EBP-homologus protein mRNA expression and X-box-binding protein-1 mRNA splicing. Taken together, our data suggest that D3G is capable of masking the EGCG-induced cytotoxicity and ER stress, presumably through up-regulation of antioxidant enzymes and heat shock proteins. (C) 2012 Elsevier Inc. All rights reserved.
  • Satoko Akiyama, Atsushi Nesumi, Mari Maeda-Yamamoto, Mariko Uehara, Akira Murakami
    BIOFACTORS 38(3) 226-233 2012年5月  査読有り
    Sunrouge, an anthocyanin-rich tea, has similar levels of catechins as Yabukita, the most popular green tea cultivar consumed in Japan. Green tea polyphenols (GTPs) have attracted interest due to their potent antioxidative activities combined with a lack of side effects in humans at normal consumption levels. However, we previously reported that high doses (0.5 and 1%) of dietary GTPs can result in deterioration of colitis and failed to prevent colon carcinogenesis in inflamed colons. In the present study, we determined the inhibitory effects of Sunrouge on colitis in dextran sodium sulfate (DSS)-treated and untreated control mice. Five-week-old female ICR mice were administered a single dose of Yabukita or Sunrouge (extracts in 1 mL distilled water) via a stomach tube for 3 weeks. After 1 week of treatment, the mice were divided into four groups (two Yabukita and two Sunrouge groups) and given drinking water with or without 3% DSS for 2 weeks, then they were euthanized. Those treated with DSS developed watery diarrhea and bloody stools, and showed body weight loss, spleen hypertrophy, and shortening of the colon, as well as deteriorations in survival rate, liver function, colon mucosal interleukin-1 beta level and expression of phase II detoxification enzyme mRNA. Sunrouge improved these DSS-induced symptoms, at least in part, whereas Yabukita showed either no effect or adverse effects in regard to some those parameters. It is suggested that the differences between Yabukita and Sunrouge on DSS-induced colitis might be due to the high levels of anthocyanins found in Sunrouge tea. (c) 2012 International Union of Biochemistry and Molecular Biology, Inc.
  • Sayo Ueno, Ryo C. Yanagita, Kazuma Murakami, Akira Murakami, Harukuni Tokuda, Nobutaka Suzuki, Takeshi Fujiwara, Kazuhiro Irie
    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY 76(5) 1041-1043 2012年5月  査読有り
    Six bryostatins were isolated from Japanese bryozoan by evaluating their binding to the C1B domain of protein kinase C delta (PKC delta). Structure-activity studies of bryostatins 4, 10, and 14 suggested that the ester group at C20 was not necessary for binding to and activating PKC delta. These bryostatins showed significant anti-tumor-promoting activity in induction tests with the Epstein-Barr virus early antigen.

MISC

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講演・口頭発表等

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担当経験のある科目(授業)

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