Soy Protein Research(Japan)

35-1

Effect of Water-soluble Okara Fiber Used in School Lunch on Health Improvement in Children

Masayo KANEDA*1, Eiko MURAI2, Chieko TOYAMA3, Misako HIROTA4, Yasuko HARADA5 and Saori HIDAKA6

1Junior College of Kagawa Nutrition University, Tokyo 170-8481
2Marugame Municipal Ayauta Junior High School, Kagawa 761-2406
3Toki Municipal Hida Elementary School, Gifu 509-5115
4Moriyama Municipal Moriyama Elementary School, Shiga 524-0041
5Fukuroi Municipal Asabahigashi Elementary School, Shizuoka 437-1101
6Yasu Municipal Chuzu Elementary School, Shiga 520-2412

ABSTRACT
Fiber intake has decreased with decreasing intakes of cereals and vegetables in Japan. Effects of fiber on life-style related diseases such as cardio-vascular disease, diabetes mellitus, abnormal blood lipid concentration and obesity are known. For Japanese adult male and female, more than 19 and 17 g/day are recommended respectively, however, recent national nutrition survey shows the intake is only 16 and 14 g, respectively. According to the report of dietary survey of children by Japan Sport Council, intake of fiber was 12.3 g and 14.0 g in 3rd grade of elementary school and second grade in junior high school student, respectively on the days when school lunch was given. Recommended fiber intake by School Lunch Dietary Reference intake was 5 g for 3rd and 4th elementary school student and 6.5 g for Junior high school student, which did not meet the recommendation. To improve the problem, we tried to use Soluble OKARA Fiber (SOF) developed by Fuji Oil Company first in the world for making new menus together with taste evaluation by children. We found that SOF is effective to improve the taste of foods without extra works for cook. Furthermore, It helps to increase soybean and vegetables which are rich in fiber. In Study 1, we studied the effects of SOF on the mprovement of dietary pattern. In Study 2, the effects of continuous use of SOF on the health of children and also the attitude of gurdians.
Soy Protein Research, Japan 17 , 1-7, 2014.

Key words : Soluble OKARA Fiber, school lunch menu, fiber intake, dietary patternnutrition teacher
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35-2

Metabolic Systems Research Based on the Diversity of Gene Resource in Glycine Max

RYuji SAWADA*

RIKEN Center for Sustainable Resource Science, Yokohama 230-0045

ABSTRACT
Diverse plant metabolites are thought to be important for plant growth and physiology, and metabolome analysis has been useful in many research fields. Thus, we have established a practical metabolomics strategy: widely targeted metabolomics. We have already reported the metabolome quantitative locus (mQTL) analysis by linkage mapping strategy. Using the leguminous plants Lotus japonicus and Glycine max, we successfully identified the mQTLs. This linkage mapping is based on the significant differences in parent lines, which are the origin of recombinant inbred lines. Thus, linkage mapping is not suitable for large scale bioresources and diverse bioresources. Using high speed sequence methods, a huge number of single nucleotide polymorphisms (SNPs) have been reported in plant genomes. The genome-wide SNPs were also used for QTL analysis based on association mapping, and this was termed genome-wide association study (GWAS). In this study, we conducted metabolome analysis for 80 lines of the worldwide G. max core collection. Finally, we provide a matrix as follows: 175 metabolites accumulation data versus 240 samples (80 lines by 3 biological replicates). Using analysis of valiance (ANOVA) and principal component analysis (PCA), the metabolome data suggested no trend. Using the Pearson correlation coefficient (PCC > 0.9), we successfully elucidated the specific network groups: amino acid, flavonoid, nucleotide and sugar. These metabolite accumulation patterns in G. max lines will used for mQTL analysis based on the GWAS.
Soy Protein Research, Japan 17, 8-12, 2014.

Key words : metabolomics, linkage mapping, association mapping, Pearson correlation coefficient, multivariate analysis.

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35-3

Investigation of Enzymes for Biosynthesis of Triterpenoids (Lupeol and Betulinic acid) in Soybean

Mikio NAKAZONO*

Laboratory of Plant Genetics and Breeding, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601

ABSTRACT
Internal aeration is important for the adaption of plants to oxygen-deficient conditions. In soybean (Glycine max), secondary aerenchyma, which plays an important role in oxygen transport from shoot to roots, newly differentiates from the secondary meristem (phellogen), providing a porous secondary tissue in the hypocotyls or roots under flooded conditions. To identify genes involved in the secondary aerenchyma formation, we performed a microarray analysis using RNA extracted from laser microdissection-isolated secondary aerenchyma in hypocotyl. We found that triterpenoid biosynthesis-related genes such as Lupeol synthase (LUS) and Cytochrome P450 monooxygenase 716A (CYP716A) were up-regulated in the secondary aerenchyma, suggesting that some triterpenoids (i.e. lupeol and betulinic acid) are synthesized in the secondary aerenchyma. In the soybean genome, there are at least 2 LUS genes (GmLUS1 and GmLUS2) and at least 3 CYP716A genes (CYP716A37, CYP716A38 and CYP716A40). Among these, we confirmed that GmLUS1 and GmLUS2 have activities for lupeol biosynthesis and CYP716A38 and CYP716A40 have activities for betulinic acid biosynthesis. Moreover, quantitative RT-PCR and in situ RNA hybridization analyses showed that GmLUS1, CYP716A38 and CYP716A40 were highly expressed in the secondary aerenchyma. These results suggest that lupeol and betulinic acid are accumulated in the secondary aerenchyma in soybean hypocotyl.
Soy Protein Research, Japan 17, 13-17, 2014.

Key words : betulinic acid, hypocotyl, lupeol, secondary aerenchyma, triterpenoid
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35-4

Genetic Control of Saponin Components in Soybean Seeds Using Marker-Assisted Selection

Masao ISHIMOTO*1, Yoshitake TAKADA2, Yuya TAKAHASHI3 and Chigen TSUKAMOTO3

1National Institute of Agrobiological Sciences, Tsukuba 305-8602
2National Agricultural Research Organization Western Region Agricultural Research Center, Zentsuji 765-8508
3Faculty of Agriculture, Iwate University, Morioka 020-8550

ABSTRACT
Soybean is an excellent source of physiologically active metabolites in addition to high-quality proteins and fats. Triterpene saponins, soyasaponins, are major components of the secondary metabolites and exhibit wide structural diversity, and their chemical properties and pharmacological effects vary depending on the structure. Group A saponins are the primary cause of the bitter astringent aftertaste, while DDMP saponins and their derivatives are suspected to have human health benefits. The structural diversity dependent on the soybean genotypes is explained by different combinations of nine spontaneous alleles at four genetic loci, Sg-1, Sg-3, Sg-4, and Sg-5, which control the sugar chain moieties of soyasapogenol glycosides and the presence of soyasapogenol A. Therefore, they appear to control saponin components genetically and partly to improve soybean quality and functional properties. Soybean hypocotyls accumulate a high amount of diversified saponins, but the excision of hypocotyl for the saponin phenotype analysis disrupts seed germination. We therefore applied marker-assisted selection (MAS) to control saponin composition by the combination of the four loci. The molecular markers were selected or designed based on their positional information, and they were validated by the analysis of a population segregating the three loci, except Sg-4. We precisely screened target phenotypes according to the combination of marker genotypes, indicating that the positional information including molecular markers here enables an efficient breeding of new varieties that might accumulate profi table saponins with health benefits and improved taste for soy food processing.
Soy Protein Research, Japan 17, 18-24, 2014.

Key words : DNA marker, marker-assisted selection, soyasaponin, aglycon, glycosyltransferase
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35-5

Molecular Genetic Study of Temperature Responsive γ-Tocopherol Methyltransferase Genes in Soybean Seeds

Tetsuya YAMADA*, Kohei MARUYAMA and Jun ABE

Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589

ABSTRACT
Tocopherol content and composition were examined in mature seeds obtained from six soybean varieties grown under different temperature conditions (low, middle, and high) during the seed filling. Three of six varieties increased the total tocopherol content in seeds filling under the high temperature condition. There was no significant difference in total tocopherol content in the other varieties. We focused on the content of α-tocopherol in seeds filling under the different temperature conditions, because α-tocopherol possesses the highest vitamin E activity in mammals. The content of α-tocopherol was significantly increased in seeds of all varieties grown under the high temperature condition, indicating that high temperature during seed filling enhanced the biosynthesis of α-tocopherol in soybean seeds. There was a varietal difference for the amount of increased α-tocopherol. The expression levels of γ-tocopherol methyltransferase (γ-TMT) and methyl-6-phytyl-1,4-benzoquinone methyltransferase (MPBQMT) genes, which were closely related to the biosynthesis of α-tocopherol, were evaluated in seeds filling under the different temperature conditions by quantitative RT-PCR analysis. The gene expression analysis revealed that the expression of γ-TMT2 among three γ-TMT genes was significantly increased in seeds of five varieties grown under the high temperature condition in comparison with those grown under other temperatures. On the other hand, there was no change for the expression of the MPBQMT gene in most varieties grown under the [?drop?] different temperature conditions. We concluded that the expression of the γ-TMT2 gene in response to temperature during seed filling was closely associated with the biosynthesis of α-tocopherol in soybean seeds grown under the different temperature conditions.
Soy Protein Research, Japan 17, 25-31, 2014.

Key words : Glycine max, tocopherol, seed filling, temperature, gene expression
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35-6

Swallowing Simulator Developed to Clarify Physical Features of Food Suitable for People with Swallowing Difficulties

Yukihiro MICHIWAKI*, Takahiro KIKUCHI and Mitsuhiro SONOMURA

Oral Surgery Division, Japanese Red Cross Musashino Hospital, Tokyo 180-8610

ABSTRACT
A parameter study using the swallowing simulator Swallow Vision® was performed to clarify food texture suitable for people with swallowing difficulties. Two types of numerical model were made from medical images: a 25-year-old healthy volunteer and a 78-year-old patient with a history of aspiration pneumonia. The two models were clearly different from each other in features and swallowing movement. The Newtonian liquid flow was analyzed using MPS method (Particleworks®) among the meshless numerical methods. The results provided new knowledge about shear rate changes over time and distinct differences between the two models. The swallowing simulator was considered useful in analyzing every affect involving swallowing difficulties from patients to food texture. Additional study is necessary to analyze the effects of non-Newtonian fluid and elastic food on swallowing difficulties.
Soy Protein Research, Japan 17, 32-36, 2014.

Key words : Swallowing difficulty, Swallowing Simulator, Food texture, Shear rate
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35-7

Search and Analysis of Taste-related Proteins from Soybean

Akiko IBUKA*, Ami MOMIE and Sachi SATO

Department of Material and Biological Chemistry, Faculty of Science, Yamagata University, Yamagata 990-8560

ABSTRACT
Miraculin is a taste-modifying protein that acts to convert sour stimuli to sweet perceptions. To date, several sweet proteins (thaumatin, monellin, mabinlin, pentadin, and brazzein) and two taste-modifying proteins (miraculin and neoculin) have been isolated and studied. Though most of them, including miraculin, are from tropical or semitropical plants, many miraculin-like proteins (MLPs) are known to exist in a wide range of agricultural plants, such as soybean, tobacco, and grape. In this study, a gene that encodes a miraculin-like protein from soybean (SoyMLP) was cloned. Its deduced amino acid sequence was 44% identical to that of miraculin. Subsequent construction of expression vectors resulted in the successful expression of recombinant SoyMLP both in Escherichia coli and Pichia pastoris. Recombinant SoyMLP secreted by P. pastoris was purified with cation-exchange liquid chromatography, and the purified protein was observed as a single band by Coomassie blue staining SDS-PAGE. The results of size-exclusion chromatography analysis indicated that SoyMLP existed as a monomer, while miraculin was reported to form a homodimer. Preliminary sensory tests showed that recombinant SoyMLP had no detectable taste-modifying activity. A cysteine residue was introduced to SoyMLP by site-directed mutagenesis, to construct dimeric SoyMLP with taste-modifying activity. But the result of size-exclusion chromatography indicated that the mutant SoyMLP (SoyMLP-Cin) still existed as monomer.
Soy Protein Research, Japan 17, 37-41, 2014.

Key words : miraculin, taste-mofidying activity, miraculin-like protein, trypsin inhibitor
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35-8

Improvement of Taste of Protein Hydrolyzate by Protease Using a Microbial Enzyme

Hideyuki SUZUKI* and Tomoki TAMURA

Laboratory of Applied Microbiology, Division of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Kyoto 606-8585

ABSTRACT
Commercially available glutaminase from Bacillus amyloliquefaciens was subjected to Western blot analysis. It reacted with anti-Escherichia coli GGT. We therefore invented a method to utilize it as a GGT. Hydrolyzate of soy protein (FUJIPRO F) was made using protease from B. licheniformis. The hydrolyzate was γ-glutamylated using glutaminase and L-glutamine. The bitterness of the hydrolyzate of soy protein was dramatically reduced and kokumi was enhanced by γ-glutamylation. The result showed that γ-glutamylation is a powerful method to improve the taste of protein hydrolyzate.
Soy Protein Research, Japan 17, 42-45, 2014.

Key words : kokumi, protein hydrolyzate, umami, glutaminase, γ-glutamyltranspeptidase
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35-9

Analysis of Bitterness-Suppressing Mechanism by Fatty Acid and the its Application

Tomiko ASAKURA*

Taste Science, Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657

ABSTRACT
Soy-bean is an important lipid and protein source. Soy-bean is known to contain about 20% lipid and few free fatty acids. Free fatty acids were identified in a natural white cheese mold as bitterness-suppressing compounds. In this study the binding potential between oleic acid and the bitter compounds was estimated by isothermal titration calorimetry (ITC). These results suggest that oleic acid suppressed bitterness by interaction with the bitter compounds. We analyzed the bitterness-suppressing mechanism by fatty acid using ITC on bitter substance, mainly quinine. These results indicated that the structure of bitter compounds had two common parts, similarly that of fatty acids had another two common parts. The common part of bitter compounds showed that the first was a nitrogen atom and the second was an aromatic ring. The fatty acid's parts showed that the first was carboxylic acid and the second was an alkyl chain. We estimated that the first interaction between the nitrogen atom in the bitter compound and the carboxylic acid in the fatty acid, and the second interaction between the aromatic ring and the alkyl chain caused the changes in the conformation of the bitter compound and the bitter activity decreased. We expect that fatty acid can be used a food additive and also is produced in foods fermented by microorganisms, such as miso.
Soy Protein Research, Japan 17, 46-51, 2014.

Key words : quinine, fatty acid, oleic acid, bitter substance, bitter taste
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35-10

Effects of Dietary Proteins on Putrefactive Compound Production in the Intestine

Takashi KUDA*

Laboratory of Food Microbiology, Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Tokyo 108-8477

ABSTRACT
Edible brown algae and soy-beans are used as major food materials in Far East Asian countries, particularly in South Korea and Japan. Brown algae contain fermentable dietary fibers, alginic acid (uronic acid polymer) and laminaran (β-1,3-glucan), that are fermented into organic acids by intestinal bacteria. In our previous study, high concentrations of soy-protein in the diet induced the putrefactive compounds indole, H2 S and phenol. The inhibitory effects of laminaran and alginate on the formation of ammonia, indole compounds and phenol compounds, putrefactive and harmful compounds, induced from soy-protein by human fecal microflora, were examined in vitro. Laminaran was fermented to lactate about 4 mmol/L. Compared with a control culture without dietary fiber, alginate increased acetate and propionate. Although both of these polysaccharides inhibited formation of the putrefactive compounds, the inhibitory effect of laminaran was higher. Rats were fed a diet containing 20% (w/w) soy-protein and 2% (w/w) laminaran or alginate. Laminaran increased cecal lactic acid content about two times and lowered pH from 7.3 to 6.3. Laminaran suppressed about 50% of indole production in the cecum. Alginate also suppressed cecal indole and phenol. These results suggest that both the fermentation and physical properties of laminaran and alginate correlated with their inhibitory effects against accumulation of the putative risk markers for colon cancer.
Soy Protein Research, Japan 17, 52-57, 2014.

Key words : soy protein, intestinal putrefactive compounds, laminaran, alginate: brown algae
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35-11

High-Absorbable Soy Peptides Revealed by the Analysis of Substrate Multispecificity of a Human Peptide Transporter

Keisuke ITO*, Takayasu MOTOYAMA, Sayuri KITAGAWA, Ryuji KATO and Yasuaki KAWARASAKI

1Department of Food and Nutritional Sciences, University of Shizuoka, Shizuoka 422-8526
2Research & Development Division, Fujioil. Co., LTD., Tsukubamirai 300-2497

ABSTRACT
The peptide uptake system that involves members of the proton-coupled oligopeptide transporter (POT) family is conserved across all organisms. POTs can recognise as many as 8,400 types of di- and tripeptides. In this study, the substrate multi-specificity of human POT, hPEPT2, was elucidated by comprehensive analysis using a dipeptide library. Among the 337 dipeptides, the Ki values of 321 dipeptides for hPEPT2 were successfully determined. The dipeptide affinities toward hPEPT2 showed a wide distribution range from 0.0033 mM to 0.55 mM. Aromatic amino acids and branched-chain amino acids frequently appeared in the high-affinity dipeptides. In contrast, the low-affinity dipeptides had a high frequency of acidic amino acids. The substrate multispecificity of hPEPT2 was similar to that of yeast POT, Ptr2p. These results suggests that POT family transporters possess similar substrate multi-specificities that allow them to preferentially uptake peptides containing high-value amino acids that are difficult to biosynthesize. The substrate multispecitficity of human POT indicates that the dipeptides containing aromatic or branched-chain amino acids are high-absorbable soy peptides.
Soy Protein Research, Japan 17, 58-62, 2014.

Key words : peptidetr ansporter, hPEPT2, substrate multispecificity, soy peptides, Saccharomyces cerevisia
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35-12

Mechanism of Gene Regulation of Lipid Metabolism by Soy Isoflavone via Nuclear Receptors

Yasutomi KAMEI*

Laboratory of Molecular Nutrition Graduate School of Life and Environmental Sciences Kyoto Prefectural University, Kyoto 606-8522

ABSTRACT
Lifestyle-related diseases arise from a complex interaction between genetic and environmental factors. It has been suggested that epigenetics, such as DNA methylation, may be involved in the molecular basis for such interactions. Epidemiological and animal studies have suggested that metabolic diseases in adulthood may be acquired during fetal events, including maternal consumption of soy products. In the present study, we obtained the following data: 1) We characterized DNA methylation in primary cultures of mouse hepatocytes treated with a ligand of PPARα (a target of soy isoflavone). A genome-wide DNA methylation analysis identified hyper-and hypo-methylated genes in the presence of the PPARα ligand. 2) Expression of glycerol-3-phosphate acyltransferase 1 (GPAT1), which encodes a rate-limiting enzyme for de novo lipogenesis in the liver, was found to be regulated by DNA methylation of the GPAT1 promoter, which contains SREBP-responsive elements, during the neonatal period. 3) Maternal administration of soy isoflavone (daidzein) was performed during gestation and lactation by intraperitoneal injection. Pups after weaning were fed a high-fat diet to induce obesity. Maternal administration of daidzein markedly suppressed diet-induced obesity in their offspring. Detailed mechanisms are currently under investigation.
Soy Protein Research, Japan 17, 63-70, 2014.

Key words : ipid metabolism, DNA methylation, obesity, isoflavone, PPAR
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35-13

Protein Expression and Functional Regulatory Mechanism of a Neuroprotective Protein, "Neuroglobin"

Nozomu TAKAHASHI and Keisuke WAKASUGI*

Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo 153-8902

ABSTRACT
Mammalian neuroglobin (Ngb) protects neuronal cells under conditions of oxidative stress. The mechanism underlying this function is only partly understood. We previously showed that human Ngb acts as a guanine nucleotide dissociation inhibitor (GDI) for the α-subunits of heterotrimeric Gi/o proteins (Gαi/o) and inhibits reductions in cAMP concentration, leading to protection against cell death. It has been reported that 17β-estradiol induces upregulation of Ngb expression. In the present study, we checked the effect of the phytoestrogen daidzein, an isoflavone found in soybeans, on upregulation of Ngb expression and found that daidzein upregulates the level of Ngb protein expression as does 17β-estradiol. In order to investigate the more detailed neuroprotective mechanism of Ngb, we created human E60Q Ngb mutant and clarified that Glu60 of human Ngb is a crucial residue for its GDI and neuroprotective activities. Moreover, we invest igated structural and functional properties of human wild-type and E60Q Ngb proteins and demonstrated that the neuroprotective effect of human Ngb is due to its GDI activity and not due to its scavenging activity against reactive oxygen species.
Soy Protein Research, Japan 17, 71-75, 2014.

Key words : neuroglobin, estradiol, daidzein, oxidative stress, neuroprotection
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35-14

Isolation of an Anti-Cancer Compound that Inhibits the mRNA Maturation Process from Soyaflavone and Food Chemical Research

Seiji MASUDA*

Laboratory of Molecular Biology of Bioresponse, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502

ABSTRACT
The inhibitory activity of mRNA maturation process was observed in soya-flavone fraction using a screening system that monitored the mRNA processing steps. The purification of the active compound was attempted and is on-going. And the individual flavones that are potentially included in the soya-flavone fraction were screened. Several compounds showed the inhibitory effect. Their structures were highly analogous. This result suggests that an unidentified structure-activity relation is required to inhibit the mRNA maturation. The detailed analysis of the content of these flavonoids in the soya-flavone fraction and the establishment of efficient isolation methods of these flavonoids are necessary.
Soy Protein Research, Japan 17, 76-79, 2014.

Key words :
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35-15

Characterization of Skeletal Muscles in Daidzein-Fed Mice

Masahiro OGAWA and Ryoichi YAMAJI*

Laboratory of Nutrition Chemistry, Course of Biological Chemistry, Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka 599-8531

ABSTRACT
Skeletal muscle mass is different between males and females, although most studies are focused on the effects of functional food components on skeletal muscle mass without consideration of sex difference. Soy food is a rich source of isoflavones including genistein and daidzein, which exert weak estrogen-like activities through binding to two isoforms of the estrogen receptor (ER), ERα and ERβ. We previously reported that daidzein inhibits estrogen-increased USP19 expression by activating ERβ and consequently represses estrogen-decreased skeletal muscle mass in ovariectomized young female mice. However, it is unknown what the effects of daidzein on skeletal muscle mass in female and male mice under normal physiological conditions are. In this study, we evaluated the effects of daidzein on the quantity and quality of skeletal muscle under normal physiological conditions. Dietary daidzein increased soleus and gastrocnemius muscle masses and decreased USP19 expression levels in soleus and gastrocnemius muscles in female mice, but not in male mice. Furthermore, dietary daidzein increased the isometric force of the plantarflexor muscle only in female mice. When we assessed the effects of daidzein on the quantity and quality of skeletal muscle in castrated male mice, dietary daidzein had no influence on muscle mass, USP19 expression level, or the isometric force of muscle. Furthermore, daidzein promoted fusion of myoblasts and caused hypertrophy of myotubes during myogenesis of C2C12 cells. These results suggest that daidzein represses USP19 expression level and consequently increases the soleus and gastrocnemius muscle masses and the isometric force of muscle only in female mice under normal physiological conditions.
Soy Protein Research, Japan 17, 80-84, 2014.

Key words : isoflavone, daidzein, skeletal muscle, sex difference, ubiquitin-specific peptidase 19
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35-16

Study of Food Components with the Ability to Increase Human ZIP4 Expression to Improve Zinc Absorption

Taiho KAMBE*

Division of Integrated Life Science, Graduate School of Biostud ies, Kyoto University, Kyoto 606-8502

ABSTRACT
Zinc is an essential nutrient for human health. It plays critical roles in diverse biological responses as a structural, catalytic, and regulatory component within proteins. Recently, people with marginal zinc deficiency and suboptimal zinc status have been detected in both less developed and industrialized countries. Strategies for increasing zinc absorption are important to prevent marginal zinc deficiency, because the efficiency is estimated to be about 30% in normal conditions. In the intestinal epithelial cells, the zinc transporter ZIP4 (SLC39A4), which was identified as a responsible gene for the rare, autosomal recessive genetic disease acrodermatitis enteropathica, functions as an essential molecule for zinc absorption. Exogenous expression of ZIP4 results in zinc uptake into the cells, suggesting that food factor(s) increasing ZIP4 expression should be a potential enhancer of zinc absorption. In previous studies, we had found that several soybean extracts including soyaflavone HG and soyhealth SA have this effect. Here, we identified a type of soyasaponin from soyhealth SA as an important active component. Moreover, we investigated the molecular mechanism by which soyhealth SA increases ZIP4 expression. Furthermore, we screened soybean extract(s) with the ability to increase human ZIP4 expression using MDCK FLp-In™ T-Rex cells stably expressing human ZIP4, and found some extracts that have the effect. These results strongly suggest that soybean extracts may be potential enhancers of zinc absorption.
Soy Protein Research, Japan 17, 85-89, 2014.

Key words : zinc transporter, ZIP4, zinc absorption, soyhealth SA, soyasaponin, endocytosis
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35-17

The relationship between Serum Isoflavone Level and Brain Volume/Cognitive Function in Elderly Subjects

Ichiro TSUJI*1, Yasutake TOMATA1, Benjamin THYREAU2, Yasuyuki TAKI2,3, Takashi WATANABE1, Kemmyo SUGIYAMA1, Mana KOGURE1, Wan-Ting CHOU1, Kenji HONKURA1, Yu KAIHO1, Kaneyuki MATSUO1, Yumi SUGAWARA1, Toshimasa SONE1,4, Hideko TAKAHASHI1, Masako KAKIZAKI1 and Jun AIDA5

1Division of Epidemiology, Department of Public Health and Foren sic Medicine, Tohoku University Graduate School of Medicine, Sendai 980-8575
2Division of Medical Neuroimaging Analysis, Department of Community Medical Supports, Tohoku Medical Megabank Organization, Tohoku University, Sendai 980-8575
3Department of Nuclear Medicine and Radiology, Institute of Deve lopment, Aging and Cancer, Tohoku University, Sendai 980-8575
4Department of Rehabilitation, Faculty of Health Science, Tohoku Fukushi University, Sendai 980-8575
5Department of International and Community Oral Health, Tohoku University, Graduate School of Dentistry, Sendai 980-8575

ABSTRACT
BACKGROUND: Previous research reported that cognitive function and frontal lobe function are improved by consumption of soy isoflavones. However, the relationship between soy isoflavones and hippocampal atrophy, that is atrophy in a memory-related region, was unclear. The present study investigated the impact of isoflavones on brain volume and cognitive function among elderly people. METHODS: We conducted a comprehensive geriatric assessment of 112 community-dwelling Japanese individuals aged ≥ 65 years from 2012 through 2013. Serum isoflavones (genistein, daidzein, equol, glycitein) were measured by High-performance liquid chromatography/tandem mass spectrometry from frozen blood samples. Brain gray matter volumes were calculated by the voxel-based morphometry method from brain magnetic resonance image data. We used a cognitive function score (MMSE) as a secondary outcome. The regression analysis-adjusted sex and age was used. RESULTS: Mean age was 81.3 years and the proportion of men was 50.9%. The correlation between serum isoflavones and brain gray matter volumes of all regions including the hippocampus was not significant (p<0.05). A significant relationship was not found for the cognitive function score. CONCLUSIONS: A significant relationship was not found between serum isoflavones and brain volume/cognitive function.
Soy Protein Research, Japan 17, 90-94, 2014.

Key words : soflavone, brain volume, cognitive function, magnetic resonance image, elderly
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35-18

The Effect of Soy Protein Intake during Pregnancy and Lactation on the Metabolic Syndrome Onset Risk of the Offspring

Tsuyoshi TSUDUKI*

Laboratory of Food and Biomolecular Science, Graduate School of Agriculture, Tohoku University, Sendai 981-8555

ABSTRACT
The maternal nutritional status during pregnancy and lactation influences the risk of obesity in offspring, but the details of this phenomenon are unclear. In particular, there is little information on the influence on the offspring of the maternal food substance intake during pregnancy and lactation. Therefore, in this study, I examined the influence of soy protein intake in dams during pregnancy and lactation on the risk of obesity in offspring, using C57BL/6J mice. The mice were fed a control diet (CD) and soy protein diet (SPD) during pregnancy and lactation. Male offspring were weaned at 3 weeks old and fed a high-fat diet for 12 weeks to induce obesity. As a result, SPD intake in dams reduced both lipid accumulation in the white adipose tissue of offspring and adipocyte hypertrophy in offspring. The underlying mechanism may involve an increase in the activation of the lipid metabolism system via the activation of PPARγ in the white adipose tissue of offspring. In conclusion, our results show that soy protein intake during pregnancy and lactation inhibits development of diet-induced obesity in male off spring.
Soy Protein Research, Japan 17, 95-98, 2014.

Key words : pregnancy and lactation, high-fat diet, offspring, obesity, soy protein
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35-19

The Effect of Soy Protein β-conglycinin on Nonalcoholic Fatty Liver Disease and NASH

Tomomi YAMAZAKI*

Department of Nutritional Science, National Institute of Health and Nutrition, Tokyo 162-8636

ABSTRACT
The prevalence of obesity in Western societies has increased dramatically, due in large part to high-sucrose and high-fat diets. The consequences of obesity include the emerging epidemics of hepatic steatosis and nonalcoholic fatty liver disease (NAFLD). Fatty liver has been thought to be benign. However, it is a precursor of nonalcoholic steatohepatitis (NASH), which progresses to cirrhosis in up to 25% of patients. Soy protein is composed of the two major proteins, β-conglycinin and glycinin. β-Conglycinin is known to decrease plasma TG concentrations and is considered to have protective effects against fatty liver. Mice fed a high-fat diet, especially one with saturated fat-rich oil, develop fatty liver with an increase in PPARγ2 protein in the liver. The fatty liver induced by a high-fat diet is improved by the knockdown of liver PPARγ2. In our previous study, β-conglycinin could reduce PPARγ2 protein and prevent high-fat-diet-induced fatty liver in ddY mice. We analyzed the effects of soybean β-conglycinin on NAFLD induced by a high-fat diet in ddY mice. Mice with obesity induced by a high-fat diet for 8 weeks were fed a high-fat diet (60 en%), middle-fat diet (30 en%) or low-fat diet (10 en%) for 5 weeks. Either β-conglycinin or casein was given as dietary prot ein. β-Conglycinin supplementation did not improve NAFLD. A high-fat diet increase d PPARγ2 and target mRNA in the liver, but β-conglycinin did not reduce these increases.
Soy Protein Research, Japan 17, 99-102, 2014.

Key words : NAFLD, β-conglycinin, high-fat diet, PPARγ2

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35-20

Feeding Soy Protein Isolate and Soybean Peptide Has a Preventive Effect on Bedsore in Rat Skin

Yuichi OISHI*, Mari SHIMURA, Midori Zengyo and Yuka MORIOKA

Department of Nutritional Science and Food Safety, Faculty of Applied Bioscience, Tokyo University of Agriculture, Tokyo 156-8502

ABSTRACT
The preventive effects of soy protein isolate (SPI) or soybean peptide (SP) on bedsore were investigated in rat skin. Thirteen-week-old male HWY/Sic rats were fed on experimental diets and had a load of 300 g on the dorsal surface for 16 days. The 6 experimental groups (n=6) were a group feeding on 20% casein diet ad libitum (C), a group feeding on 14 g/day of 20% casein diet (CR), a group fe eding on 14 g/day of 18% casein diet containing 2% collagen peptide (COL), a group feeding on 14 g/ day of 20% SPI diet (SPI), a group feeding on 14 g/day of 20% SP diet (SP), and a group feeding on 14 g/day of 18% SP diet containing 2% collagen peptide (SP+COL). After 16 days, rats had a wound on the dorsal. The wound area of the C group was the smallest, whereas the area of the CR group was the largest. The area of the COL, SPI, and SP groups was smaller than that of the CR group. The level of type III tropocollagen and the mRNA level of Col3α1 in the periwound skin increased in the COL and SP groups relative to the levels in the CR group. The amounts of hyaluronan and the mRNA level of hyaluronan synthase 3 were larger in the periwound skin of the COL and SP groups than those in the periwound skin of the CR group. The increment of type III collagen and hyaluronan is highly relevant to wound-healing. Furthermore, the feeding on soybean peptide increases the amount of serum adiponectin, which has amplifying effects on collagen and hyaluronan synthesis. These results suggested that SP might have preventive effects on bedsore via the increase of type III tropocollagen, hyaluronan and serum adiponectin.
Soy Protein Research, Japan 17, 103-109, 2014.

Key words : bed sore, collagen, hyaluronan, soybean peptide

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35-21

Novel Hypocholesterolemic Oligopeptides Derived from Soybean

Satoshi NAGAOKA*

Faculty of Applied Biological Sciences, Gifu University, Gifu 501-1193

ABSTRACT
This experiment was designed to identify oligopeptides which have hypocholesterolemic activity from soybean β-conglycinin α'subunit. At first, in vitro screening related to the micellar solubility of cholesterol, we found that tryptic hydrolysates of soybean β-conglycinin α'subunit, ESEGSESQR, ESE EEEEDQDED or EEEEE derived from soybean β-conglycinin α'subunit exhibited a significant decrease in micellar solubility of cholesterol compared to control. Secondly, we evaluated the effects of ESEGSESQR, ESEEEEEDQDED or EEEEE on taurocholate binding capacity in vitro. Taurocholate binding capacity tended to increase with their peptides. In caco-2 cells, ESEGSESQR treatment significantly decreased an intracellular cholesterol level accompanying a significant increase in the intestinal cholesterol efflux to the apical side. Furthermore, we tried to clarify the molecular mechanism of the decrease in micellar solubility of cholesterol by VAWWMY (soystatin) by physicochemical studies. The micellar paticle size of taurocholate was almost 5 d. nm. VAWWMY containing taurocholate micellar particle size was 200 d. nm - 1,000 d. nm. We found for the first time that VAWWMY (plus charge) binds with taurocholate (minus charge) mediated by an electronic mole cular interaction accompanying the changes in the micellar particle size of taurocholate.
Soy Protein Research, Japan 17, 110-115, 2014.

Key words : β-conglycinin, VVFLASVS, soystatin, bile acid, micelle, peptide
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35-22

Effect of Peptides Derived from Soy Protein on Glucose Metabolism

Takafumi MIZUSHIGE*

Research Unit for Physiological Chemistry, Center for the Promotion of Interdisciplinary Education and Reserch, Kyoto University, Uji, Kyoto 611-0011

ABSTRACT
It has been reported that β-conglycinin, a soybean deposit protein, exhibits a glucose metabolism-improvement effect. We previously found that soymorphin, which is a β-conglycinin derived pentapeptide, exhibits a blood glucose lowering effect by activating insulin sensitivity after adiponectin secretion in KKAy mice, a model of type 2 diabetes mellitus. The soymorphin is released by the enzyme reaction of elastase and leucine aminopeptidase. In the current study, we found that pepsin-pancreatin digestion, mimicking gastrointestinal enzymatic conditions, of β-conglycinin lowered blood glucose after insulin administration. Thus, we must consider the possibility that novel β-conglycinin derived peptide with glucose metabolism improvement effect is released by the pepsin-pancreatin digestion of β-conglycinin. Moreover, we tried to identify the functional peptide candidate and to clarify the mechanism of the blood glucose lowering effect by injection of pepsin- pancreatin digest into mice.
Soy Protein Research, Japan 17, 116-119, 2014.

Key words : β-conglycinin, peptide, glucose metabolism, glucose uptake, C2C12
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35-23

Effects of Okara on Glucose Tolerance in Diabetic Rats

Masaya HOSOKAWA*, Michiko KATSUKAWA, Hiroshi TANAKA, Hitomi FUKUDA and Nobuko IRITANI

Faculty of Human Sciences, Tezukayamagakuin University, Sakai 590-0113

ABSTRACT
Okara, tofu residue, is rich in insoluble dietary fiber. Furthermore, considerable amounts of soy proteins are included in okara. Recently, isoflavone was reported to improve glucose tolerance, but the effects of okara on glucose tolerance remain to be elucidated. In the present study, we aimed to investigate the therapeutic effects of okara on glucose tolerance in Goto-Kakizaki (GK) rats, which are the animal model of type 2 diabetes mellitus in Japanese. Male GK rats (8-10 weeks old) were fed a 10% lard diet with or without 5% dry okara powder for 2 weeks. Body weight gain and food intake of the two groups of rats were not significant. In an oral glucose tolerance test, the increases of plasma glucose and insulin levels were suppressed by the okara diet. In epididymal adipose tissue, the mRNA expressions of PPARγ and adiponectin, which up-regulate insulin sensitivity, were increased by feeding the okara diet. These results suggest that okara may exert anti-diabetic effects through the PPARγ-mediated pathway in type 2 diabetes.
Soy Protein Research, Japan 17, 120-123, 2014.

Key words : okara, PPARγ, adiponectin, diabetes, GK rat
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35-24

Basic Analysis of Hatching Stimulants of Soybean Cyst Nematodes

Shinsaku ITO*

Faculty of Applied Bioscience, Tokyo University of Agriculture, Tokyo 156-8502

ABSTRACT
Soybean cyst nematode, which is one of the most harmful pathogens of soybean, parasitizes the roots of legumes. Hatching of soybean cyst nematode is initiated by recognition of a hatching factor produced by legumes. One of the hatching factors, glycinoeclepins (GEs), was identified in the roots of kidney beans as a hatching stimulant for soybean cyst nematode. However, the effects of GEs on legumes and their biosynthetic pathway(s) have not been determined. In this study, we performed RNA-sequence analysis using GEA-treated plants to identify the GEA-responsive genes. We identified 19 down-regulated and 51 up-regulated genes in GEA treated plants.
Soy Protein Research, Japan 17, 124-126, 2014.

Key words : soybean cyst nematode, glycinoeclepin, RNA-seq
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35-25

Characterization of the Quality of Imbibed Soybean at an Early Stage of Pre-Germination for the Development of a New Protein Food Item

Tomoko TAMURA*

Department of Nutrition and Food Safety, Faculty of Applied Bioscience, Tokyo University of Agriculture, Tokyo 156-8502

ABSTRACT
This is a pilot study to develop a new protein food item from imbibed soybean before germination. The present work noticed the significant of a short stage after imbibition and before germination and we found that vitamin C production was activated in as short as 16 h from the start of imbibition, without particular influence on the soy protein quality and sensory acceptability, while longer imbibition made the imbibed soybean activate its phytophysiological metabolism for germination. DNA microarray analysis followed by gene ontology statistics revealed that, prior to 16 h, (i) genes for carbohydrate metabolism giving rise to nutrients as the primary metabolism were up-regulated; (ii) genes response to water-, te mperature-, and light- stimulation which may not be related to soybean protein properties were down-regulated; and (iii) gene associated with lipid metabolism and secondary metabolite production were changed. This information will contribute to better understanding how to develop a new soy protein item in pregermination before active physiological processes begin.
Soy Protein Research, Japan 17, 127-134, 2014.

Key words : soybean; imbibition; pregermination; DNA microarray
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35-26

Aerobic Stability of Mixed Feeds with Fermented Soybean By-product

Makoto KONDO*1, Masashi HARAZAKI1, Shuichi KARITA2 and Masakazu GOTO1

1Graduate School of Bioresources, Mie University, Tsu, 514-8507
2Graduate School of Regional Innovation Studies, Mie University, Tsu, 514-8507

ABSTRACT
The aim of this study is to reveal the effect of raw or ensiled okara on the aerobic stability of mixed feeds for dairy cattle. Three types of okara were prepared for this research; raw okara (RO), fermented okara without any additives (FO) and fermented okara with dried beet pulp (FO+BP) to decrease moisture level. Each types of okara was mixed with hay, grains and so on to make mixed feeds for dairy cattle. These mixed feeds were put into plastic bottles and they were incubated aerobically for 5 days at 30°C to determine their aerobic stability. As an indicator of deterioration, the temperature of the mixed feeds including RO and FO+BP increased around 1 day after incubation, while the FO treatment maintained ambient temperature for 3 days and then slowly increased, but did not show visual deterioration until day 5. During these 5 days, the amount of yeast in the mixed feed with RO and FO+BP rapidly increased within 1 day; in contrast, that in the FO slowly increased after 3 days. Only the mixed feed with FO decreased its pH and increased lactic and acetic acid content under aerobic conditions up to day 3. Even so, the level undissociated fatty acids in the FO treatment was still lower than the reported minimum inhibitory concentration for yeast growth in feed. It can be assumed that antifungal compounds other than short-chain fatty acids may be contained in fermented okara or newly produced under aerobic condition.
Soy Protein Research, Japan 17, 135-140, 2014.

Key words : fermented okara, dairy feed, aerobic stability, yeast
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35-27

Development of Shellac-Coated Enteric Tablets Containing Soybean Peptides

Seitaro KAMIYA* and Kenichiro NAKASHIMA

Division of Pharmaceutical Technology, Faculty of Pharmaceutica l Sciences Nagasaki International University, Nagasaki 859-3298

ABSTRACT
[Objective] Shellac has been considered as a potential enteric coating agent due to its alkaline dissolution properties. However, this has not been realized owing to the lack of dissolution in second fluids, as determined by disintegration tests. Thus, we investigated the possibility of using shellac as an enteric coating agent. [Method] Tablets containing soybean peptides were coated with a mixture of shellac and eggshell calcium suspended in ethanol by immersion. The coated tablets were then evaluated by various commonly used disintegration tests. [Results] No soybean peptides were released into either the first or the second fluid when the tablets were coated using shellac alone. When we coated the tablets using a combination of shellac and eggshell calcium, the soybean peptide release was inhibited with the first fluid, whereas 55% of the soybean peptides was released with the second fluid. [Discussion] Complete disintegration of a soybean peptide tablet coated with shellac alone within one hour with the second fluid was difficult. Elution improved when eggshell calcium was added to the coating, which may be attributed to the dissolution of the eggshell calcium by the first fluid, causing the release of soybean peptides through pores in the traces of the eggshell calcium coating.
Soy Protein Research, Japan 17, 141-144, 2014.

Key words : shellac, enteric coating tablets, soybean peptides, eggshell calcium
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35-28

The Evaluation of the effect of Soybean β-Conglycinin on Glucose Metabolism in Wistar Rats by Oral 13C-Glucose Administration

Nao INOUE*, Asuwa FUNAYAMA and Ikuo IKEDA

Laboratory of Food and Biomolecular Science, Graduate School of Agricultural Science, Tohoku University, Sendai, 981-8555

ABSTRACT
Previously, we suggested that β-conglycinin (β-CG) prevents the development of type 2 diabetes through the improvement of carbohydrate metabolism and insulin sensitivity in GK rats. However, though serum glucose and insulin levels were significantly lower in the β-CG group as compared with the casein group, there was no significant difference in OGTT. From these results, we hypothesized that OGTT caused stress in the experimental animals from continuous tail blood sampling. Therefore, we evaluated the effect of soybean β-CG on glucose metabolism in Wistar rats by oral 13C-glucose administration. Male GK rats were fed an AIN-93G diet containing casein or β-CG for 1wk. As the result of respir atory gas analysis after oral 13C-glucose administration, the peak of 13C/ 12C rate appeared faster in the β-CG-fed rats than in the casein-fed rats. The serum adiponectin level was significantly higher in the β-CG-fed rats, but there were no significant differences in serum glucose and insulin levels. Serum and hepatic triacylglycerol levels in the β-CG-fed rats were significantly lower. The feeding of β-CG suppressed the activities of enzymes related to fatty acid synthesis and enhan ced the activity of carnitine palmitoyltransferase in the liver compared to the feeding of casein. In this study, we showed that the measurement of energy metabolism by oral 13C-glucose administration was an effective alternative evaluation to OGTT. Furthermore, we clarified that soybean β-CG improved carbohydrate metabolism through the preferential glucose consumption and the enhancement of adipone ctin secretion.
Soy Protein Research, Japan 17, 145-149, 2014.

Key words : β-conglycinin, Wistar rats, 13C-glucose, glucose metabolism, energy metabolism
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35-29

Effects of Isoflavones Derived from Soy Beans on Muscle Atrophy

Katsuya HIRASAKA*1,2, Tasuku MAEDA2, Marie HARUNA2, Tomoki ABE2, Arisa OCHI2, Ayako OHNO-MAITA2, Shigetada TESHIMA-KONDO2, Shigeto TANIYAMA1, Katsuyasu TACHIBANA1 and Takeshi NIKAWA2

1Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Nagasaki 852-8521
2Department of Nutritional Physiology, Institute of Health Biosc iences, The University of Tokushima Graduate School, Tokushima 770-8503

ABSTRACT
Ubiquitin-proteasome-dependent proteolysis contributes to a progression of age-associated muscle atrophy (sarcopenia). Our previous report has shown that isoflavones derived from soy beans prevent the muscle-specific ubiquitin ligase MuRF1-mediated muscle atrophy through SIRT1 activation in C2C12 myotubes. In this study, we examined the effect of isoflavones derived from soy extracts in atrophied muscle of mice. The intake of soy isoflavone prevented reduction of muscle wet weight and myofiber size. The expression of SIRT1 in muscle of mice fed the soy isoflavone diet was slightly increased, compared with that of mice fed the normal diet. However, there were no significant differences between the normal and soy isoflavone diets in the expression of Atrogin-1 and MuRF1. Sarcopenia causes dysfunction of neuromuscular junction as well as a decrease in muscle strength and mass. Interestingly, soy isoflavone protected the expression of acetylcholine receptors impaired by denervation. These results suggest that isoflavones suppress age-related muscle atrophy through an improvement of neuromuscular junction.
Soy Protein Research, Japan 17, 150-155, 2014.

Key words : muscle atrophy, ubiquitin ligase, isoflavone
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35-30

Isoflavone Intake Improves Lacrimal Function

Takaaki INABA*

Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582

ABSTRACT
Isoflavone is one of the polyphenolic compounds abundantly contained in beans. Much evidence is available on isoflavone as a functional food factor, particularly for its prominent antioxidant activity among the various polyphenolic compounds. To clarify the efficacy of the antioxidant activity of isoflavone in dry eye disease, we conducted the following study. As a result of feeding an experimental diet with 0.1% of isoflavone to the decreased tear-production model mice, no changes in the body weight and food intake were observed; however, the decrease in tear volume was significantly suppressed. Elucidating the association between the ant ioxidant effects of isoflavone and tear secretion is crucial for preventing and/or treating dry eye disease, as it is assumed to be increasingly prevalent as a lifestyle disease.
Soy Protein Research, Japan 17, 156-158, 2014.

Key words : soflavone, dryeye, lacrimal gland, tear, oxidative stress
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35-31

Elucidation of Mechanisms Underlying Sex Differences in Alleviation Effects of Lung Cancer Risk by Soy Isoflavone

Satoshi ENDO*, Toshiyuki MATSUNAGA and Akira IKARI

Laboratory of Biochemistry, Department of Biopharmaceutical Sciences, Gifu Pharmaceutical University, Gifu 501-1196

ABSTRACT
A recent study at the Japan National Cancer Center showed that isoflavone intake was inversely associated with lung cancer risk in Japan. In this report, the inverse association was found in non-smoking males, but not in females. As mechanisms such as apoptotic induction and inhibition of angiogenesis by isoflavones cannot explain sex differences in the attenuating effect on lung cancer risk, we focused on differences in plasma concentrations of steroid hormones between males and females. The inhibitory effects of isoflavones and soybean components, soyaflavone HG, on the activity of 17β-hydroxysteroid dehydrogenase type 5 (17βHSD5) , which is involved in steroid hormone synthesis, were examined in this study. Among isoflavones, daidzein and genistein inhibited 17βHSD5. These two isoflavones and soyaflavone HG also inhibited androsterone metabolism dependent on 17βHSD5 in lung cancer A549 cells. Next, we tested 17βHSD5 inhibitory activity, of various flavonoids such as monohydroxyflavones, flavanone, D-(+)-catechin and calcones in order to develop flavonoid analogues which have more potent inhibitory activity, and found that 7-hydroxyfl avone had a potent inhibitory activity against 17βHSD5. Among 12 derivatives of 7-hydroxyflavone, pratol (7-hydroxy-4'-methoxyflavone) showed the most potent 17βHSD5 inhibitory activity. Molecular docking studies revealed that a hydrogen bond between 7-hydroxy group of pratol and the main chain of Asp224 and hydrophobic interaction of 4'-methoxy group with hydrophobic residues such as Phe306 and Pro318 might be involved in the binding of pratol with the enzyme. These results, it is suggested that we can contribute to the elucidation of mechanisms underlying the sex-differentially attenuating effect of soy isoflavones on lung cancer risk and to the development of novel inhibitors of 17βHSD5.
Soy Protein Research, Japan 17, 159-163, 2014.

Key words : lung cancer, steroid hormone, 17β-hydroxysteroid dehydrogenase type 5, isoflavone, structure-activity relationships
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35-32

Examination of the Function of the GPR120 in Perivascular Adipose Tissue and Anti-atherogenic Action by Isoflavone Ingestion

Takanori YAMAZAKI*1, Yasukatsu IZUMI2, Soichi SANO1, Takehiro YAMAGUCHI1 and Minoru YOSHIYAMA1

1Department of Cardiovascular Medicine, Osaka City University Graduate School of Medicine, Osaka 545-8585
2Department of Pharmacology, Osaka City University Graduate School of Medicine, Osaka 545-8585

ABSTRACT
Introduction: An anti-atherogenic action by isoflavone ingestion has been shown by some reports. However, the details of the mechanism are unknown. In this study, we investigated the relation of the anti-atherogenic action by isoflavone ingestion and adipokine of perivascular adipose tissue (PVAT), and the influence on circulation dynamics. Methods: Spontaneously hypertensive rats (seven weeks old, male) were divided into 3 groups: a vehicle group (V), a group treated with 40 mg/kg/day of daidzein (D), and a group treated with 20 mg/kg/day of genistein (G). Wister Kyoto rats were used as control, and each treatment agent was administered for two weeks. After treatment, we compared the effects of D and G in hemodynamics, cardiac function, atherogenic action and genetic analysis of PVAT. Results: Although no significant intergroup differences were noted in the mean blood pressure, heart rate, left ventricular weight, and the thickening of tunica media, echocardiographic study revealed that D treatment significantly attenuated hypertension-induced left ventricular diastolic dysfunction. Compared with the V group, mRNA expressions of adiponectin, G-protein coupled receptor 120, collagen-3, and transforming growth factor-β1 were of no significance in the PVAT of the D and G groups. On the other hand, compared with the control group, mRNA expressions of brain natriuretic protein were significantly elevated in the left ventricular tissue of the V and G groups. In contrast, D suppressed the expressions. Conclusions: Although the blood pressure of nine-week-old male spontaneously hypertensive rats was elevated, tunica media thickening did not cause. Daidzein may prevent hypertension-induced left ventricular diastolic dysfunction.
Soy Protein Research, Japan 17, 164-168, 2014.

Key words : daidzein, genistein, hypertension, left ventricular diastolic function
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35-33

Effects of Equol on Insulin Secretion by Pancreatic β-Cells

Hiroko HORIUCHI, Rie SHIRAI and Naoki HARADA*

Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, 599-8531

ABSTRACT
Insulin secretion steadily decreases in the development of non-obese type 2 diabetes mellitus (T2DM) in Asian patients. Insulin is secreted by pancreaticβ-cells in response to elevated glucose levels in the blood. Therefore, the improvement of insulin secretion not only by sustaining an adequate β-cell mass but also by inducing β-cells to secrete more insulin is crucial for the prevention of T2DM in Asians. In the present study, we investigated the effects of S-equol, which is produced from the soy isoflavone daidzein by intestinal microflora, on glucose-stimulated insulin secretion in pancreatic β-cells. S-Equol enhanced insulin secretion of isolated mouse islets under high, but not low, glucose conditions. R-Equol did not have this effect. S-Equol also increased insulin secretion of INS-1 rat β-cells in high glucose conditions, whereas 17β-estradiol did not. These results show that S-equol enantiospecifically enhances glucose-stimulated insulin secretion through a mechanism different from estrogen signaling. Thus, S-equol might be a potential agent for the prevention of T2DM.
Soy Protein Research, Japan 17, 169-173, 2014.

Key words : pancreatic β-cells; S -equol; glucose-stimulated insulin secretion; type 2 diabetes mellitus
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