Improvement of Defecation Habits of Primary School Children by Increase of Dietary Fiber Intakes in School Lunch.
Masayo KANEDA*1, Eiko MURAI2, Chieko TOYAMA3, Misako HIROTA4, Yasuko HARADA5 and Saori HIDAKA6
1Institute of Nutrition Sciences Kagawa Nutrition University, Tokyo 170-8481
2Marugame Municipal Ayauta Junior High School, Kagawa 761-2406
3Ena Municipal Ooidaini Elementary School, Gifu 509-5115
4Moriyama Municipal Moriyama Elementary School, Shiga 524-0041
5Iwata Municipal Iwataminami Elementary School, Shizuoka 437-1101
6Kusatu Municipal Shibukawa Elementary School, Shiga 520-2412
ABSTRACT
The low dietary fiber intake of school children is one of problems in dietary habits in Japan. The target of dietary fiber intake was not set until 2014 because it was thought to be hard to discuss the relationship between the incidence of life stylerelated disease and dietary fiber intakes for those under the age of 17. However, from the view point that the school years are an important life stage to establish dietary habits, the target for dietary fiber intake has been set for every two years from 6 years old to 17 years old in the dietary reference of intakes for Japanese (2015) (DRI 2015). At the primary and junior high school levels, dietary fiber intakes from school lunch have not reached the target set in DRI and nutrition teachers report that the dietary fiber is one of nutrients to be considered in making the menus for school lunch. We developed various menus with the addition of soluble okara fiber powder (SOF) and achieved adequate dietary fiber in the school lunch. We have made a manual about SOF use; how to and how much to add in cooking for school lunch and new users of SOF could easily introduce SOF into their school lunches. Our research revealed the possibility of expanding the use of SOF at schools nationwide and might contribute to suffi cient dietary fiber intakes by school children. In addition, our trial of the increase in dietary fiber in school lunch by addition of SOF led families to consume more vegetables and more dietary fiber at home through the experience of children with school lunch. However we could not clarify a direct relationship between the addition of SOF to school lunch and daily defecation habits or characteristics of intestinal flora; the patterns of intestinal flora were different in schools with different dietary fiber intakes, suggesting an increase of dietary fiber influenced the patterns of intestinal flora.
Soy Protein Research, Japan 18, 1-11, 2015.
Key words : soluble okara fiber, school lunch menu, fiber intake, defecation habits, nutrition teacher
Study of the Molecular Targets of Metabolic Improvement Caused by Soy Protein Intake
Ryuichiro SATO, Makoto SHIMIZU, Hiroyasu INOUE* and Rieko NAKATA*
Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657
*Department of Food Science and Nutrition, Nara Women's University, Nara 630-8506
ABSTRACT
C57BL/6 mice were fed a high-fat diet containing either casein or β-conglycinin for 9 weeks. Blood parameters were improved and increased weight gain was suppressed by β-conglycinin consumption, consistent with several previously published results. The wet weights of adipose tissues of mice fed the β-conglycinin diet were significantly lowered, reflecting the inhibition of body weight gain. Analyses of the expression of the genes related to heat generation in subcutaneous white adipose tissue (subWAT) reveal that ucp-1 gene expression was increased by β-conglycinin. In contrast, there were no major changes in brown adipose tissues. Moreover, increased FGF21 gene expression was observed in subWAT of mice fed the β-conglycinin diet. When FGF21-deficient mice were fed the same set of diets for 9 weeks, the mRNA levels of ucp-1 in subWAT were substantially low and kept constant even after β-conglycinin consumption. Taken together, the anti-obesity effect of β-conglycinin consumption might be partly accounted for by an increase in heat generation caused by increased ucp-1 expression in subWAT. It may also be concluded that FGF21 is involved in the up-regulation of ucp-1 gene expression. Further studies are needed to elucidate the mechanism by which FGF21 gene expression in subWAT is increased by β-conglycinin ingestion.
Soy Protein Research, Japan 18, 12-16, 2015.
Key words : β-conglycinin, FGF21, ucp-1
Development and Validation of Molecular Markers in Breeding for Seed Protein Components and Content in Soybean
Takashi SAYAMA1, Masakazu TAKAHASHI2, Kunihiko KOMATSU3 and Masao ISHIMOTO*1
1National Institute of Agrobiological Sciences, Tsukuba 305-8602
2Kyushu Okinawa Agricultural Research Center, National Agricultural Research Organization Koshi 861-1192
3Agriculture, Forestry and Fisheries Research Council, Ministry of Agriculture, Forestry and Fisheries, Tokyo 100-8950
ABSTRACT
Compositions and contents of seed proteins are significant targets in soybean breeding. Soybean seeds comprise~40% protein, mostly consisting of the globulins, β-conglycinin (7S globulin) and glycinin (11S globulin). 7S and 11S globulins comprise three subunits (α', α, and β) and five subunits (A1aB1b, A2B1a, A1bB2, A5A4B3 and A3B4), respectively, and the respective subunits are encoded by CG-α', CG-α and CG-β and gy1 , gy2 , gy3 , gy4 and gy5 , respectively. Spontaneous or induced mutants lacking these subunits were identified except for β subunit. In addition, Scg-1 that control the deficiency of all 7S globulin subunits was identified from a wild soybean accession. Soybean seeds also contain three lipoxygenases, L-1, L-2 and L-3, that cause an undesirable bean flavor. Mutants that lack one of three enzymes were identified from soybean germplasm. Thus, the compositions of these proteins can be controlled genetically. Therefore, we designed the molecular markers to select the mutants based on their gene structures or positional information, and they were validated by the analysis of a population segregating the mutant loci. We precisely screened target phenotypes according to the combination of marker genotypes, indicating the molecular markers developed here facilitate an efficient breeding for seed protein compositions. In order to control seed protein content, we conducted quantitative trait locus (QTL) analysis using three recombinant inbred line (RIL) populations, which derived from the crosses between the parents differing in protein contents, and detected several stable QTLs beyond planting year and field. Although these QTLs were dependent on the RILs, the pyramiding of these QTLs could enable the new varieties with a high protein or oil content.
Soy Protein Research, Japan 18, 17-27, 2015.
Key words : DNA marker, β-conglycinin, glycinin, lipoxygenase, marker-assisted selection, quantitative trait locus, recombinant inbred line
Omics for Metabolism Study for Soybean Seed Development
Yuji SAWADA*
*RIKEN Center for Sustainable Resource Science, Yokohama 230-0045
ABSTRACT
Dynamic metabolic changes have been estimated in soybean seed development and fungal inoculation. In this study, soybean accession "Fukuyutaka", which is number one production in Japan, was used for our omics approaches. Our goal is integrated omics approaches for elucidation of metabolic change and its regulation.
Generally, primary metabolites for plant physiology are known metabolites, which can purchase. In plant specific secondary metabolites, very limited standard metabolite can purchase. Thus, we need un-targeted metabolomics for detection of unknown structural metabolites. Using LC-QTOF-MS, molecular weight related ion (MS1) and its fragmented ions (MS2) were automatically detected for all detectable metabolites. The MS1 and MS2 information can search for MS and MS2 database. Using dry seed, seed development samples (day after seedling 1-8: DAS1-8) and fungal inoculated at DAS2, total 51 samples were applied for the un-targeted metabolomics. As the results, 472 metabolites candidate were detected as MS1 and MS2. The annotation rate based on the database search was more than 70%. The metabolic profiles were clearly shown the diverse and dynamic metabolic changes. In multivariate analysis, DAS3 was identified as a key point for the metabolic change. Key metabolic profi les in principal component 1 (PC1) of principal component analysis was significantly change based on the seed development. Key metabolic change in PC2 was significantly change based on the fungal inoculation. These metabolic changes also confirmed in widely targeted metabolomics based on the standard metabolites. To elucidate the co-accumulation of metabolites, we carried out correlation network analysis. We successfully found an isoflavone group, which was including genistin (genistein glycoside). In future study, gene expression profiles will be collected by using RNA sequence technology. The integrated omics approaches will give us overview of soybean metabolic changes in seed development and fungal inoculation.
Soy Protein Research, Japan 18, 28-34, 2015.
Key words : seed development, fungal inoculation, un-targeted metabolomics, multivariate analysis, RNA sequence.
Effect of Polymorphism of Nitrogen Fixation Related Gene on Soybean Yield
Akihiro SUZUKI*
Agrobiology & Agro-production Systems, Department of Environmental Sciences, Faculty of Agriculture, Saga University, Saga 840-8502
ABSTRACT
Many leguminous plants establish symbiotic relationship with nitrogen-fixing soil bacteria, called rhizobia. Symbiotic nitrogen fixation is regulated by many QTLs. Therefore Identification of localization of such QTLs is important for increase of legume grain yield. We carried out QTL analysis by use of Recombinant Inbred Lines (RILs) derived from the second generation prepared by cross of Gifu B129 and Miyakojima MG20 of model legume Lotus japonicus . As a result, we found that there is a loci which works positively on activity of nitrogen fixation on chromosome 4 of MG20. Interestingly, it is known that SEN1 gene also localizes near this position and sen1 mutant do not show nitrogen fixation activity. This shows that SEN1 gene is involving in nitrogen fixation. Moreover, SEN1 protein of B129 has one amino acid deletion compared with that of MG20. Based on these facts, there is a possibility that SEN1 gene is the cause of the QTL. Actually, nitrogen fi xation activity of sen1 mutant transformed by intact MG20 SEN1 gene was higher than that of B129 SEN1 . Then we found polymorphism in amino acid sequence of soybean SEN1 genes. Nitrogen fixation activity of L. japonicus sen1 mutant transformed by Enrei SEN1 gene was slightly higher than that of Peking type SEN1 gene. Effect of polymorphism of soybean SEN1 gene on the soybean yield was analyzed using 18 F2 soybean plants prepared from crossing with Bay (Peking type) and Enrei. Unfortunately, due to the difference of flowering time between Enrei and Bay, significant difference was not observed. For the test of soybean production, soybean plant which have Enrei type SEN1 gene in the Fukuyutaka background should be used.
Soy Protein Research, Japan 18, 35-40, 2015.
Key words : soybean, nitrogen fi xation, symbiosis, rhizobia, SEN1
Analysis of Attractant of Plant Parasitic Nematode
Shinichiro SAWA*
Graduate school of Science and Technology, Kumamoto University Kumamoto 860-8555
ABSTRACT
Because of the agricultural importance, the soybean cyst nematode Heterodera glycines that infect soybean (Glycine max ) and Meloidogyne incognita that infect many crops have emerged as good research models to understand the signaling, perception, and response events during plant-nematode interactions. The recent advances in our understanding of the cellular, physiological, and molecular basis of legume-nematode interactions are merging at the crossroads of plant-microbe interactions and plant developmental biology. Plant attraction of plant parasitic nematodes is thought to be a soluble chemical that is perceived by nematodes, and nematode can recognize where the plant is. In order to increase knowledge of molecular mechanisms underling of plant-animal interaction, analysis of plant attractant of plant parasitic nematode is one of the most impressive and smart theme. Furthermore, this theme can be applied to agriculture field. Here we have developed devices to evaluate the nematode guidance activity, and one guidance behavior was confi rmed when the nematode are packed in a small space in detail. Further, we could detect plant attractant activity from roots of some plant species. We could observe many nematodes can be attracted at the root tip of Maize and some other plants. The attraction was confi rmed by using PF127 gel, which is well known for nematode behavior evaluation gel. If we could identify the chemical structures of the attractant, we could develop new agricultural chemical that can utilize for the defense of the nematode damage.
Soy Protein Research, Japan 18, 41- 44, 2015.
Key words : nematode, Arabidopsis, attractant, chemical, M. incognita
Isolation of Natural Bioactive Compounds Against Plant Pathogenic Oomycete Phytophthora Sojae
Shigeru KITANI* and Takuya NIHIRA
International Center for Biotechnology, Osaka University, OSAKA 565-0871
ABSTRACT
Phytophthora sojae , belonging to oomycetes, is responsible for root- and stem-rot disease in soybean, and causes multibillion dollar losses in worldwide agriculture. Until now, considerable attention has been paid over the last two decades to the biological control of the plant pathogen. Although the use of synthetic chemicals has been effective to prevent the outbreak of the plant disease, it might provide negative effects on non-target organisms or the development of pest resistance, suggesting that there is a need to develop alternative control systems to replace or complement conventional pesticide usages, such as by finding new natural control agents. Here, we performed the screening of the endophytic actinomycetes that show anti-oomycete activity, and the purification and identification of antioomycete compounds from the culture broth. Ninety-two percent of the endophytic actinomycetes that had anti-yeast activities inhibited the growth of Phytophthora sojae P6497 by a dual culture agar assay, indicating that anti-yeast assay is a useful and rapid method to find biocontrol agents against P. sojae . From the crude extract of endophytic Streptomyces griseus HN46 showing an inhibitory activity toward P. sojae , actinophenol, which is known as an anti-fungal compound, was identified as a major metabolite, based on both the MS analysis and NMR analysis. Unfortunately, the bioassay demonstrated that actinophenol did not inhibit the mycelial growth of P. sojae . Our endophytic actinomycetes showing anti-P. sojae activity may contribute to the development of biocontrol agents against P. sojae .
Soy Protein Research, Japan 18, 45-49, 2015.
Key words : plant pathogenic oomycete, Phytophthora sojae , streptomycetes, Streptomyces , biocontrol agent.
Explanation on the Usage and Suitability of Emulsions Made Utilizing Emulsifying Properties of Soy Protein Isolate
Kazuko HIRAO*, Nobuko EGI, Saori MITSUBOSHI and Kyoko SAIO
Aikoku Gakuen Junior College, Tokyo 133-8585
ABSTRACT
By first emulsifying oil with a suspension of water and Proleena 800 (Fuji Oil Co., Ltd. - hereafter shortened to SPI800), and then adding vinegar and mixing, a smooth emulsion with high stability and no bean taste or smell was able to be obtained. Using Scheffé's simplex lattice design 10 emulsions were made with varying ratios of SPI800, oil, and vinegar and water. Based on these ratios the physical properties of the emulsions differed, with ratios containing high amounts of oil found to be favored. When flavoring the emulsion, adding sugar to the emulsion itself was found to obstruct firmness. However when sugar was mixed with SPI800 before emulsification an emulsion with a sweet taste and firmness was produced. By using the above method and adding vinegar, salt and other seasonings and spices a firm dipping sauce was made. Furthermore, by using the method of adding sugar before emulsification, the solubility of SPI800 improved and it was possible to lessen the amounts of water and oil required. By mixing this with soft flour, sugar and baking powder baked cakes were made. These cakes swelled favorably, had a soft texture and in sensory evaluation tests were found to have no significant bean taste.
Soy Protein Research, Japan 18, 50-57, 2015.
Key words : SPI, emulsion, viscosity, sensory evaluation, baked cakes, sugar
Analysis of Bitterness-Suppressing Mechanism by Fatty Acid and the its Application
Taro MASUDA*
Laboratory of Food Quality Design and Development, Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011
ABSTRACT
Iron is an essential transition metal for virtually all the living kingdoms. Soybean seed, which is one of the most major staple crops, contains a large amount of iron. Thus, it is expected as a candidate for sustainable food-derived iron source. It is suggested that the iron storage protein ferritin largely contributes to the net iron content in the seed of soybean. Previously, the author showed that ferritin is composed of two types of subunits, SFER1 and SFER2, in soybean dry seeds. In the present study, the author investigated the contribution of ferritin to the iron content of soy-derived processed foods, such as tofu. Ferritin was detected in many kinds of soy-derived foods except the fermented soy foods. Furthermore, ferritin purified from the tofu extract was folded properly and formed oligomer, similar to the structure of native soybean ferritin, indicating that soybean ferritin was stable during the heat treatment of food processing. Judging from the ferritin and iron recovery in the purifi cation process, most of the soluble iron was contained in ferritin oligomer. However, the iron contents of ferritin from tofu was approximately 1150 Fe atoms per molecule, while native ferritin oligomer, which was purified from dry seeds, contained 2590 atoms. These results suggested that ferritin oligomer was maintained stably and still contained large portion of iron in tofu, although partial denaturation induced iron release from ferritin shell during heat treatment.
Soy Protein Research, Japan 18, 58-63, 2015.
Key words : ferritin, iron content, tofu, subunit, elementary analysis
Effect of Dietary Soybean β-conglycinin on Lipid and Carbohydrate Metabolism in Type 2 Diabetes Mellitus Models, GK Rats
Nao INOUE, Asuwa FUNAYAMA and Ikuo IKEDA*
Laboratory of Food and Biomolecular Science, Graduate School of Agricultural Science, Tohoku University, Sendai 981-8555
ABSTRACT
Effects of dietary soybean β-conglycinin on lipid and carbohydrate metabolism were studied in male GK rats of type 2 diabetes mellitus models. In exp. 1, male GK rats (5wks-old) were fed an AIN-93G diet containing casein or β-conglycinin for 5 weeks. After 3 weeks of the feeding period, although there was no significant difference in OGTT, serum glucose and insulin levels were significantly lower in the β-conglycinin group as compared with the casein group. As a result of energy metabolism measurement, carbohydrate consumption was higher in the β-conglycinin-fed rats than in the casein-fed rats. Serum triacylglycerol was significantly lower and serum adiponectin level was significantly higher in the β-conglycinin-fed rats than in the casein-fed rats. In exp. 2, male GK rats were fed an AIN-93G diet containing casein or β-conglycinin for a week. As in exp. 1, serum adiponectin level was significantly higher in the β-conglycinin-fed rats. Hepatic adiponectin level in the β-conglycinin group was significantly higher than that in the casein group, but those levels of muscle and WAT were the same between the two groups. In the protein expression of insulin signaling pathway, the phosphorylation of IRS-1 and Akt was higher in the liver of β-conglycinin-fed rats. These results suggest that β-conglycinin prevents the development of type 2 diabetes mellitus through the improvement of carbohydrate metabolism and insulin sensitivity in GK rats. Furthermore, these effects were partly attributable to the enhancement of adiponectin incorporation into liver, and the improvement of insulin signaling.
Soy Protein Research, Japan 18, 64-68, 2015.
Key words : β-conglycinin, GK rats, adiponectin, lipid metabolism, carbohydrate metabolism
Transcriptome Analysis of the Effect of Soy Protein Ingestion on White Adipose Tissue in Dietary Magnesium-deficient Rats
Tomoko ISHIJIMA*1, Shogo YONEMITSU1, Yuji NAKAI2, Keiko ABE1, 3 and Shinji OKADA1
1Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657
2Institute for Food Sciences, Hirosaki University, Aomori 038-0012
3Kanagawa Academy of Science and Technology, Kawasaki 210-0821
ABSTRACT
In rat white adipose tissue, the dietary protein sources, casein and soy protein isolate (SPI), differed from each other in terms of the effect of dietary Mg-deficiency. In detail, 4-week-old male Wistar rats were fed 2 formulas with different dietary Mg levels (0.05% or 0.02%) and 2 different protein sources (casein or SPI) for 4 weeks. As a result, epididymal white adipose tissue weights were no significantly differences among the 4 diet groups, but hierarchical clustering of DNA microarray data revealed that the effects of dietary SPI on gene expression profile alteration induced by Mg deficiency was smaller than that of casein. In dietary Mg deficiency, casein feeding significantly changed the expression of 288 genes, while SPI feeding changed that of 113 genes. Changes in expression of the genes related to energy utilization induced by Mg deficiency were similar in both protein sources, whereas thermogenesis related genes were different from each other.
Soy Protein Research, Japan 18, 69-73, 2015.
Key words : soy protein isolate, Mg deficiency, energy metabolism, DNA microarray, white adipose tissue
Soy Tri-Peptide FLV and Obesity-Related Adipose Anti-Inflammation
Yoshinori MINE*1 and Rina YU2
1Department of Food Science, University of Guelph, Guelph, ON, N1G 2W1 Canada
2Department of Food Science and Nutrition, University of Ulsan, Ulsan 680-749, South Korea
ABSTRACT
Adipose inflammation plays a crucial role in the development of obesity induced metabolic disorders such as insulin resistance and type 2 diabetes. Tumor necrosis factor-alpha (TNFα), which triggers inflammatory signaling cascades in adipocytes/ macrophages, is implicated in adipose inflammation and metabolic complications such as insulin resistance. Here we demonstrate that soy peptide, the β-conglycininderived tripeptide FLV, reduces adipose inflammation and insulin resistance in vitro . Soy peptide FLV significantly inhibited MCP-1-induced macrophage migration and downregulated expression of MCP-1 receptor CCR2 in a dosedependent manner. Soy peptide FLV also decreased release of inflammatory cytokines (TNFα, MCP-1, IL-6) from co-cultured macrophages/adipocytes, and the action was mediated by inactivation of inflammatory signaling molecules (JNK, IKK, IkBα). Moreover, soy peptide enhanced insulin responsiveness and increased glucose uptake in adipocytes. Furthermore, we for the first time found that adipocytes expressed peptide transporters (PepTs) PepT1 and PepT2, and the peptide transporter inhibitor disrupted the inhibitory action of soy peptide FLV on the inflammatory responses. These findings suggest that soy peptide, which is transported to adipocytes by PepT1/2, inhibits TNFα-induced inflammatory signaling, and protects insulin resistance in the cells. Soy peptide FLV may have a potential to prevent obesity-induced adipose inflammation and insulin resistance.
Soy Protein Research, Japan 18, 74-81, 2015.
Key words : obese, type 2 diabetes, soy peptides, adipose inflammation, insulin resistance,
Alanine-scanning Mutagenesis Reveals the Di- and Tripeptide Recognition Mechanism of Ptr2p, a Proton-coupled Oligopeptide Transporter
Keisuke ITO*, Takayasu MOTOYAMA, Masaji ISHIGURO and Yasuaki KAWARASAKI
School of Food and Nutritional Sciences, University of Shizuoka, Shizuoka 422-8526
ABSTRACT
Peptide uptake systems that involve members of the proton-coupled oligopeptide transporter (POT) family are conserved across all organisms. POTs can recognize as many as 8,400 types of di- and tripeptides. In this study, the contribution of amino acid residues to the recognition of di- and tripeptides was quantitatively and systematically analyzed by alanine-scanning mutagenesis of yeast Ptr2p. Y365 of Ptr2p was involved in the recognition of the R1 side-chain of dipeptides, whereas Y248 and I251 were responsible for the recognition of the R2 side-chain of dipeptides. On the other hand, Y365, S484, and F507 greatly contributed to the recognition of the R1 side-chain of tripeptides. The R2 side-chain of tripeptides was not involved in a specific interaction with the residues in Ptr2p. Y248, S484, and F507 contributed to the recognition of the R3 side-chain of tripeptides. The contribution of the interaction with the R2 (R3) side-chain of di- and tripeptides was greater than that with the R1 side-chain. On the basis of these results, an alternative recognition model for di- and tripeptides at a single substrate-binding site is suggested as a molecular basis of POT family proteins.
Soy Protein Research, Japan 18, 82-88, 2015.
Key words : peptide transporter, Ptr2p, substrate multispecificity, dipeptides, tripeptides
In Vivo Physiological Action of a Soy Protein-Derived Multifunctional Peptide
Kousaku OHINATA*
Graduate School of Agriculture, Kyoto University, Uji 611-0011
ABSTRACT
We reported that Arg-Phe (RF), a vasorelaxing dipeptide, exhibits hypotensive and anorexigenic effects. In this study, we found that a vasorelaxing tripeptide Gln-Arg-Phe (QRF) is released by gastrointestinal protease-digestion of β-conglycinin, a major storage protein of soybean. Furthermore, we focused on pyroGlu-Arg-Phe (pERF), which was assumed to be converted by QRF, and detected in the digest. pERF exhibited vasorelaxing activity equally to RF. Both pERF- and RF-induced vasorelaxing activities were not blocked by inhibitors of nitric oxide synthase (NOS) and cyclooxygenase, which contribute to production of NO and prostaglandins already-known vasorelaxing factors. pERF also activated CCK-releaseing enteroendocrine cell STC-1. Intriguingly, pERF exhibit long-lasting hypotensive effect than RF in spontaneously hypertensive rats (SHR) after oral administration. pERF is the first pyroglutamyl peptide derived from soy protein with long-lasting hypotensive activity. The conversion to pERF was enhanced druing heat treatment.
Soy Protein Research, Japan 18, 89-92, 2015.
Key words : β-conglycinin, peptide, vasorelaxing activity, hypotensive activity, food intake regulation
Study on the Mechanisms of Improved Fermentation Ability of Yeast Cells Caused by Soy Peptides
Shingo IZAWA*
Department of Applied Biology, Graduate School of Scientifi c Technology, Kyoto Institute of Technology, Kyoto 606-8585
ABSTRACT
We have previously reported that cultivation in media containing soy peptides improves the growth and fermentation ability of Sacchaomyces cerevisiae. Compared with yeast cells cultured with casein peptone or bacto peptone, cells cultured with soy peptides showed the increase in the mRNA levels of genes involved in phospholipid synthesis. The ino4Δ and tgl3Δtgl4Δtgl5Δ mutants showed decreased growth rate in the soy peptide medium. Since they have deficiency in the transcriptional activation of genes involved in phospholipid synthesis and in the supply of fatty acids and diacylglycerol from triacylglycerol, it was considered that stagnation of phospholipid synthesis caused the delayed growth of these mutants in the soy peptide medium. Conversely, it is likely that the smooth supply of phospholipids is induced in the soy peptide medium and contributes the improved growth of yeast cells. Additionally, we found that soy peptides improve the efficiency of mutant construction, suggesting the soy peptide's utility for the breeding of brewer's yeast strains.
Soy Protein Research, Japan 18, 93-96, 2015.
Key words : soy peptides, yeast, phospholipids, spontaneous mutation
Study of the Mechanism for Yeast Transcription Activator Msn2-Regulated Amino Acid/Peptide Transporter Activity by Using Soy Peptides and Its Application
Hiroshi TAKAGI*, Noreen Suliani Binti MAT NANYAN and Daisuke WATANABE
Laboratory of Applied Stress Microbiology, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma 630-0192
ABSTRACT
We cultured the wild-type and the transcription activator Msn2-overexpressing strains of the yeast Saccharomyces cerevisiae in the medium containing soy peptides (SP) or a free amino acid mixture (FAA) with the same amino acid composition as SP as the nitrogen source and examined the cell growth. The growth stimulation effect by SP was observed in both strains, but the growth ratio of SP/FAA in the Msn2-overexpressing strain was higher than that of the wild-type strain due to the influence of the growth delay by FAA in the Msn2-overexpressing strain. Next, we cultured both strains in the medium containing 10% glucose as the carbon source and measured their fermentation abilities (carbon dioxide production). The fermentation ability was enhanced when SP was used in both strains. The effect of SP was more remarkable in the Msn2-overexpressing strain when the carbon dioxide production ratio of SPP/FA was compared. Furthermore, we analyzed the transcription level of the genes encoding typical peptide transporters (Ptr2, Opt1). Unexpectedly, the expression of these transporters was not induced by SP, but tended to be high in the FAA medium that causes growth delay. These results suggest that the effect of SP on growth and fermentation in the Msn2-overexpressing strain is unrelated to the induction of the peptide transporter genes, and raise the possibility that the activities of Ptr2 and Opt1 are increased through the unknown transporter(s) involved in the uptake of SP or indirect influence except the transcription.
Soy Protein Research, Japan 18, 97-101, 2015.
Key words : yeast, transcription activator Msn2, fermentation ability, amino acid/peptide transporter, soy peptides
Intake of Soy Protein-derived Peptides Efficiently Stimulates Central Catecholamine Synthesis and Turnover in Mouse Brain
Shigeki FURUYA1, 2, Kazuki MORIYASU1, Haruka IMAI1, Akane NAKAHATA1 and Takashi ICHINOSE1
1Laboratory of Functional Genomics and Metabolism, Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences
2Innovative-Bioarchitecture Center, Kyushu University, Fukuoka 812-8581
ABSTRACT
The aim of this study was to assess effect on the catecholamine metabolism produced by oral administration of a soy-peptide mixture Hinute-AM in the brain of C57BL/6 mice. Catecholamine analysis using a high performance liquid chromatography with electrochemical detector system demonstrated that forced oral administration of Hinute-AM increased noradrenaline metabolites 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG) and normetanephrine (NM) in the cerebral cortex and brainstem. Noradrenaline content was also significantly increased in the brainstem. A peptide mixture derived from collagens did not exhibit such action on noradrenaline and its metabolites. Enhanced noradrenaline metabolic turnover was also evident in these brain regions. These in vivo observations strongly suggest that intake of Hinute-AM leads to boost of central noradrenaline synthesis and transmission.
Soy Protein Research, Japan 18, 102-107, 2015.
Key words : soy peptide, catecholamine, noradrenaline, brain
The Role of Hippocampal Neurogenesis in the Prevention of Cognitive Impairment by Soy Isoflavones
Takahiro MORIYA*
Department of Cellular Signaling, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578
ABSTRACT
It was recently reported that the soy isoflavone have the preventive effects on the symptoms of Alzheimer model animal. On the other hand, the adult neurogenesis in the hippocampal dentate gyrus was found to be involved in the learning and memory. In this study, therefore, we tried to clarify whether the popular soy isoflavones, genistein and daidzein could affect the proliferation and the differentiation of the neural stem cells using the cultured neural stem cells and mouse models. The proliferation of the cultured neural stem cells was examined by WST-8 assay and BrdU immunohistochemistry, and the differentiation to the neurons, astrocytes and oligodendrocytes was evaluated using the immunohistochemistry for MAP2, GFAP and Rip, respectively. We found that the treatment with genistein suppressed EGF-induced cell growth of the cultured neural stem cells in a concentration-dependent manner. The treatment with daidzein, in contrary, facilitated EGF-induced cell growth of the cultured neural stem cells in a concentration-dependent manner. Both compounds failed to affect the proliferation in the absence of EGF. Daidzein moderately increased the proportion of neurons and oligodendrocytes, but not astorocytes, when treated in the differentiation-preferring medium including 1% FCS. Finally, we observed that the oral administration of daidzein increased the number of BrdU-labeled cells in the subgranular zone of hippocampal dentate gyrus of ICR mouse treated with and without Aβ1-42. These results suggest that daidzein has the facilitaing action on the hippocampal neurogenesis of mouse.
Soy Protein Research, Japan 18, 108-112, 2015.
Key words : neural stem cell, neurogenesis, hippocampus, soybean isoflavone, daidzein
Structure of Anti-cancer Compound which Inhibits the mRNA Maturation Process from Soyaflavone and Identification of its Intercellular Target Proteins
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 from soyaflavone fraction using the screening system which monitored the mRNA processing steps. Several flavonoids showed the inhibition of mRNA processing step. To examine the localization of mRNA when mRNA processing was inhibited by these flavonoids, co-immunostaining was performed with SC35, a speckle marker. mRNA was co-localized with SC35 when mRNA processing was inhibited by these flavonoids, suggesting that flavonoids inhibited the mRNA splicing. Then, to identify the intercellular target protein(s) of these flavonoids, flavonoid fixed beads and nuclear extract were used. The components of SF3a and SF3b, U2AF and SF1 were identified by mass-spec analysis. SF3a and SF3b are the components of U2 snRNP and U2AF recruits U2 snRNP to the 3' splice site. And SF1 is recruited to blanch site. These results indicates that flavonoid interacts with U2 snRNP and its associated factors. Together with the above result, flavonoids inhibit the mRNA splicing process.
Soy Protein Research, Japan 18, 113-117, 2015.
Key words : mRNA, flavonoid, speckle U2 snRNP
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. Epigenetics, such as DNA methylation, have been suggested to be involved in the molecular basis for such interactions. Epidemiological and animal studies indicated that metabolic diseases in adulthood may be acquired during fetal events, including maternal consumption of soy products. In the present study, we characterized DNA methylation in mice treated with a ligand of PPARα (a target of soy isoflavone). Using genome-wide DNA methylation analysis, we identified hyper- and hypo-methylated genes in the presence of the PPARα ligand. Analysis of mice deficient in the nuclear receptor peroxisome proliferatoractivated receptor α (PPARα) and maternal administration of a PPARα ligand during the gestation and lactation periods revealed that the DNA demethylation is PPARα dependent. Namely, we found that the ligand-activated PPARα-dependent DNA demethylation regulates the hepatic fatty acid β-oxidation genes during the neonatal period. We are currently studying the underlying mechanisms in detail. These studies will help identify the mechanism whereby maternal nutrition affects off spring early in life. The knowledge gained may enable support of proper DNA methylation status during infancy by appropriate modifi cation of the components of infant formula milk and intake of supplemental foods during pregnancy. The results of this study are expected to provide further insight into the molecular basis of metabolic diseases and lead to development of new preventative methods in the form of functional foods for the baby and mother.
Soy Protein Research, Japan 18, 118-122, 2015.
Key words : lipid metabolism, DNA methylation, obesity, isoflavone, PPAR
Effect of Soy Isoflavone on Insulin-like Growth Factor Expression in Fast Muscle
Masahiro OGAWA, Natsuha KAWATA and Ryoichi YAMAJI*
Division of Applied Life Sciences, Graduates School of Life and Environmental Sciences, Osaka Prefecture University, Sakai 599-8531
ABSTRACT
Skeletal muscle is a tissue composed of heterogeneous muscle fibers with different biochemical and contractile properties. Fast-twitch extensor digitorum longus (EDL) muscle is characterized with regard to contractile function. EDL is required for the abilities to stand up from a chair or to recover from a stumble to prevent a fall. Soy isoflavones such as daidzein have estrogenic activities and are called phytoestorgens. To investigate the beneficial effects of daidzein on fast-twitch muscle mass, ovariectomized (OVX) mice as a model of post-menopausal women were fed daidzein. The mass of EDL muscle was higher in daidzein-fed OVX mice than in control-fed OVX mice. Dietary daidzein increased the mRNA levels of total insulin-like growth factor 1 (IGF-1) and its two alternative splicing variants (IGF-1Ea and MGF) in EDL muscle. The serum levels of daidzein and S -equol in daidzeinfed OVX mice reached approximate 2μM and 0.5μM, respectively. In C2C12 myotubes, 1μM daidzein increased the mRNA levels of total IGF-1, IGF-1Ea and MGF, whereas 0.5μM S -equol had no effect on the expression of IGF-1. The serum of daidzein-fed OVX mice increased the mRNA levels of total IGF-1, IGF-1Ea and MGF in C2C12 myotubes. Likewise, the serum of daidzein-fed female rats increased IGF-1 mRNA level, and acetone-treated serum of daidzein-fed female rats had the same effect. These results suggest that dietary daidzein directly and indirectly increases IGF-1 expression in EDL muscle.
Soy Protein Research, Japan 18, 123-128, 2015.
Key words : isoflavone, daidzein, skeletal muscle, insulin-like growth factor 1, ovariectomy mice
Hippocampal Neurogenesis is Enhanced by the Soy Isoflavone Daidzein in Middle-Aged Female Mice
Jun YAMADA and Shozo JINNO*
Department of Anatomy and Neuroscience, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582
ABSTRACT
Throughout the life, production of new granule cells continues in the dentate gyrus of the hippocampus, which is called adult neurogenesis. Recent studies show that adult hippocampal neurogenesis contributes to various brain functions, such as learning, memory, and mood control, and also suggest that decline in new cell production during aging may be involved in age-related cognitive dysfunctions. Estrogens have well known effects on reproductive behaviors and associated brain regions. Interestingly, recent studies indicate that estrogens not only influence nonreproductive behaviors but also enhance adult neurogenesis. Soy isoflavones, such as daidzein and genistein, mimic physiological actions of estrogens. Here we thus examined the potential effects of daidzein on adult hippocampal neurogenesis in middle-aged (12-month-old) female mice using endogenous neurogenesis markers. The numerical densities (NDs) of primary progenitors were not affected by four weeks intraperitoneal administration of daidzein. The NDs of transit amplifying progenitors were increased by daidzein in the dorsal hippocampus (responsible for memory and learning) but not in the ventral hippocampus (responsible for emotion regulation). The NDs of neuronal progenitors and immature granule cells were increased by daidzein both in the dorsal and ventral hippocampus. We also found that the NDs of proliferating cells were higher in daidzein-treated mice than in saline controls. Furthermore, the dendritic length of immature granule cells were elongated by daidzein administration. These findings indicate that daidzein enhance proliferation and differentiation of progenitors and maturation of immature granule cells in a topographic manner, and also suggest that age-related brain dysfunctions may be reversed by daidzein via enhancement of adult neurogenesis.
Soy Protein Research, Japan 18, 129-137, 2015.
Key words : hippocampus, neurogenesis, aging, isoflavone, daidzein
Regulatory Effect of Soy Isoflavones on the Expression of Small Nucleolar RNA Expression and Its Functionality
Hirofumi TACHIBANA*, I-Chian LIN and Shuya YAMASHITA
Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581
ABSTRACT
Daidzein and genistein are polyphenolic isoflavones contained in soy, and daidzein is metabolized to equol by intestinal bacteria. The mechanisms of the physiological effects of isoflavones have been considered to be involved in estrogen receptors (ERs) in many instances, because of their avidity for ERs. On the other hands, some reports indicate the existence of ER-independent effects of isoflavones. We identified pap associated domain containing 5 (Papd5) as a responsive gene for ERindependent growth-inhibitory action of equol in cancer cells. Papd5, one of noncanonical poly(A) polymerase, has been reported to add adenyl-nucleotide residues to small nucleorar RNAs. In ER-negative human cervical HeLa cells, equol induced polyadenylation of small nucleolar RNAs (snoRNAs) in the Papd5-dependent manner, suggesting that equol induces snoRNA polyadenylation through activating Papd5. Overexpression of snoRNAs had small infl uence both on the growth of HeLa
cells and on the growth inhibitory effect of equol.
Soy Protein Research, Japan 18, 138-142, 2015.
Key words : isoflavone, estrogen receptor, Papd5, small nucleolar RNA, polyadenylation
Effect of Soy Beans Peptide AM Intake on the Skeletal Muscle Development and Physical Fitness in Elderly Person
Shigeru YAMADA1, Hitomi FUJITA1, Rina MATSUYAMA1, Maiko MIWA1, Natsumi ABIKO1, Ayumi KATSURA1, Daisuke KUMAGAWA2, Yusuke TAKAHASHI3 and Motohiro MAEBUCHI4
1Department of Food & Health Sciences, Faculty of Human Life Sciences, Jissen Women's University, Tokyo 191-8510
2Japan Institute of Sports Sciences, Tokyo 115-0056
3Department of Sciences & Engineering, Chuo University, Tokyo 112-0003
4Health & Nutrition Research Department Basic Research Institute. R&D, Fujioil Co. LTD., Tsukubamirai 300-2497
ABSTRACT
In this experiment, we investigated the effects of soybean peptide AM intake on the development and the function of skeletal muscle in the elderly (average age 80). Subjects were grouped to observe the effect of soy peptides AM uptake. The study divided subjects into two groups, one with an intake of soybean peptide Hinute AM (Fuji Oil Co., Ltd.) (Peptide Group-9 subjects) and one with a placebo intake of lactose (Placebo Group-4 subjects). We used the MR system to confirm the development of skeletal muscles. Measured skeletal muscles were the abdominal rectus muscle, the outside abdominal muscle, a major hip throw quarter, quadrate muscle of loins, a spine stand quarter, glutei maximi and a femur quarter. As a result of measurement, the muscles that were increased by soybean peptide AM intake were the rectus abdominis muscle, psoas major muscle, gluteus maximus, and femoral muscle. A physical test was performed in accordance with the Ministry of Education, Culture, Sports, Science and Technology's sport and young people bureau's "Guidelines for a new fitness test" (1999). Measurement items were grip strength, sit-up, a long seat body anteflexion, and back strength. In addition, the Timed Up&Go Test, which the Japanese Physical Therapy Association recommends, was administered. From the results of the fitness test, the only item that was increased from soybean peptide intake was back strength. Accordingly, intake of soy peptide AM was found to have an impact on the development and function of skeletal muscle. Considering characteristics of individual skeletal muscle, in the future connection we would like to examine the effect of further soybean peptide AM intake.
Soy Protein Research, Japan 18, 143-152, 2015.
Key words : soy beans peptide AM, skeletal muscle, physical fitness, MRI
Basic Study About the Effect of Soy Isoflavon on the Oral Environment of Women in Menopause
Yuko KUSAKABE*
Food Function Division, National Food Research Institute, National Agriculture and Food Research Organization, Tsukuba 305-8642
ABSTRACT
Dry mouth is one of the many disorders that affect the quality of life, because it leads not only to higher incidence of caries but also changes in taste sensitivity. Dry mouth is a common symptom in menopausal women, and the administration of female hormones can be effective in improving symptoms. However, adverse defects of these hormones often lead to reluctance to in patient. Soy isoflavone is a potential alternative to hormonal therapy owing to their structural similarity to estrogen. Therefore, we compared the effects of female hormones, and soy isoflavones (genistain and fujiflavone), on the salivary system of ovariectomized mice. We evaluated their food and water consumption, saliva production, taste sensitivity, gene expression in the taste buds and salivary glands, and salivary protein production by comparing ovariectomized mice and sham-operated mice. The results show that the administration of female hormones and soy isoflavones restore the gene expression of submandibular gland protein C (Smgc), which is decreased by ovariectomy. This effect was correlated with theirestrogenic activity. Furthermore, similar results were obtained for Smgc protein levels. Therefore, the analysis of Smgc expression in salivary glands is a suitable indicator of the effects of female hormones and soy isoflavones on salivary glands.
Soy Protein Research, Japan 18, 153-158, 2015.
Key words : soy isoflavone, salivary gland, gene expression, female hormone, dry mouth
Effect of Soy Protein, Isoflavone Metabolite and Equol Administration on the Reduction of Cardiovascular Disease Risk in the Patients with Obesity and Metabolic Syndrome
Noriko Satoh-ASAHARA*, Masashi TANAKA, Hajime YAMAKAGE and Kazuya MURANAKA
Division of Diabetic Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Kyoto 612-8555
ABSTRACT
Epidemiologic studies indicate that soy intake has an important role in the prevention of age-related health problems, such as metabolic syndrome and stroke. From our survey of nutrition examination, we revealed that the positive correlation between the intake of the soy bean product and serum levels of adiponectin. Daidzein, the principal isoflavone contained in soy, is converted to S-equol by the intestinal bacteria. Not all individuals, however, can produce S -equol, which is considered the most biologically active metabolite. We studied the effects of a natural S-equol supplement on metabolic parameters associated with overweight or obesity and metabolic syndrome. The study was a randomized, double-blinded, placebo-controlled, crossover design with no washout period. All subjects were considered overweight or obese if they had a body mass index >25 kg/m2. Placebo or natural S-equol tablets containing 10 mg S -equol were orally ingested each day for 12 weeks. A total of 54 Japanese overweight or obese outpatients were enrolled. Equol non-producers comprised 67.9% of the overweight or obese subjects. The ratio of equol non-producers in this overweight or obese subject group was higher than the previously reported ratio of equol non-producers (approximately 50%) in the general population. Compared with the placebo group, intervention with natural S-equol led to a significant decrease in HbA1c, serum low-density lipoproteincholesterol (LDL-C) levels, and CAVI score. Furthermore, the effect was more prominent in the subgroup of female equol non-producers. Natural S-equol might have a role in glycemic control and in the prevention of cardiovascular disease by its effects to lower LDL-C levels and CAVI scores in overweight or obese individuals.
Soy Protein Research, Japan 18, 159-165, 2015.
Key words : cardiovascular disease, soy protein, isoflavone metabolite, equol, obesity, metabolic syndrome
Improvement in Zinc Nutrition in Infants and Elderly by Soybean Components
Taiho KAMBE*
Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502
ABSTRACT
Zinc is an essential nutrient for human health. Since zinc plays critical roles in a variety of biological processes, its deficiency results in various disorders, in particular, in infants and elderly. Thus, investigation of strategies for achieving enough zinc absorption is important to prevent zinc deficiency. The efficiency of zinc absorption in the small intestine from a diet is estimated to be about 30% and it is known to become much less in aging and in zinc supplementation. So, improvement of the efficiency is likely more promising than simple zinc supplementation. The zinc transporter ZIP4 functions as an essential molecule for zinc absorption in the intestinal epithelial cells. Thus, food factor(s) enhancing ZIP4 expression could be a potential enhancer of zinc absorption. We have found that soyasaponin has such activity using mouse Hepa cells, but failed to reveal its effect on human ZIP4 expression, because of lacks of cultivated human cell lines expressing endogenous ZIP4. Here, we showed the positive effect of soyasaponin on human ZIP4 expression using human pancreatic carcinoma AsPC1 cells. These results strongly suggest that soybean extracts are potential enhancers of zinc absorption. In this study, we also searched another soybeans components with the ability to enhance expression of another zinc transporter ZnT2, which functions as an essential route of zinc into breast milk. Since zinc is indispensable for healthy growth and developmental of infants, breast milk has considerably higher levels of
zinc to meet infant's requirements. The effective transport of large amounts of zinc into the breast milk by the use of food factor(s) could achieve good health in breastfed infants during lactation.
Soy Protein Research, Japan 18, 166-170, 2015.
Key words : ZIP4, zinc absorption, soyasaponin, ZnT2, breast milk
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 pests of soybean, parasitizes the roots of legumes. Hatching of soybean cyst nematode is initiated by recognition of hatching factor produced by legumes. One of the hatching factors, glycinoeclepins (GEs), has been identified in roots of kidney beans (Honkintoki and Benikintoki) as hatching stimulants of soybean cyst nematode. However, their biosynthetic pathway(s) has not been uncovered. In addition, there are no reports that detect GEs except for kidney beans. In this study, to analyze the hatching stimulants of soybean cyst nematodes, we performed hatching assay by using the ethyl acetate extract of root exudates, and found the possibility that the major hatching factors in legumes are different from known GEs except for kidney beans, Honkintoki.
Soy Protein Research, Japan 18, 171-174, 2015.
Key words : soybean cyst nematode, glycinoeclepin, hatching assay
Development of a Novel Fermented Food Made with Germinated Soybean Flour and Rheological Properties during Dough Fermentation
Michiko TSUJI*
Department of Food Science and Nutrition, Faculty of Human Life and Environmental Sciences, Nagoya Women's University, Nagoya 467-8610
ABSTRACT
The rheological properties of bread made with germinated soybean flour were investigated. Specific volumes of the control bread dough (dry yeast) and mixed bread (dry yeast and Bacillus subtilis natto) decreased as fermentation time increased. The storage modulus (G'), loss modulus (G''), and loss tangent (tanδ) of the mixed bread dough were lower than those of the control bread dough. Both breads had the highest value of specific volume with 1 h of fermentation time. The hardness of each bread decreased gradually when fermented for 3 h and showed no changes after 3 h. The adhesiveness of the control bread dough decreased when fermented for 3 h; however, that of the mixed bread decreased rapidly when fermented for 1 h and showed no changes after 1 h. A sensory evaluation showed that the mixed bread with a fermentation time of 1 h had significantly higher texture acceptability than did the non-fermented control bread in terms of stickiness. With 2 h fermentation time, both breads had significantly lower acceptability of sweetness than did the non-fermented control bread. These results indicate that a softer germinated soybean flour bread could be developed by adding Bacillus subtilis natto.
Soy Protein Research, Japan 18, 175-181, 2015.
Key words : germinated soybean flour, gluten-free bread, rheological property, sensory evaluation
Soy Milk Intake Improves Stress Status in University Students
Mariko NAKAMOTO*1, 2 and Tohru SAKAI1
1Department of Public Health and Applied Nutrition, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima 770-8503
2Section of Longitudinal Study of Aging, National Institute for Longevity Science (NILS-LSA), National Center for Geriatrics and Gerontology, Obu 474-8511
ABSTRACT
Soy milk intake might be inversely associated with physical and mental stress, possibly because of its potential beneficial effects on improvement of inflammatory and oxidant stress. Clinical trials evaluated the effects on soy milk intake on stress status are limited in other ethnic people. The objective was to evaluate a shortterm effect of soy milk intake on change of stress status in young people. The study was conducted in 13 healthy young men and woman (aged 18-25 years old) in this cross-over trial (200 mL soy milk compared with water). We used salivary amylase measurements and score of psychological test, including the State Trait Anxiety Inventory and the Center for Epidemiologic Studies Depression Scale, for assessment of stress status. Difference between change on stress status during soy milk group and water group were analyzed by paired t -test. The change in salivary amylase concentration was different between soy milk and water groups significantly [The change from baseline 53.1±37.6 (kU/L) on water group vs 17.5± 13.6 (kU/L) on soy milk group, p =0.008]. There was no significant difference in the change of two mental stress variables between soy milk and water groups. Our results indicate that soy milk intake might be associated with a change in salivary amylase.
Soy Protein Research, Japan 18, 182-187, 2015.
Key words : soy milk; stress; salivary amylase; university students; a cross-over trial
Effect of a Soy Protein Isolate Preload on Postprandial Glycemic Control in Healthy Young Humans
Kashima H*1, Uemoto S1, Eguchi K1 , Endo (Yamaoka) M1, Miura A1 and Fukuba Y1
1Department of Exercise Science and Physiology, School of Health Sciences, Prefectural University of Hiroshima, Hiroshima 734-8558
ABSTRACT
Pre-meal consumption of whey protein improves the post-meal glycemic profile, whereas little information exists on the soy protein (SP). The aim of present study was to examine the effect of different amount of a soy protein isolate (SPI) consuming just before 75 g oral glucose tolerance test (OGTT) on glycemic control. Healthy eight young subjects consumed 400 mL liquid containing of SPI either 0 g (SP0), 20 g (SP20) or 40 g (SP40) in fasting morning. After 30 min from SPI consumption, the OGTT was performed to evaluate the individual glycemic control. Blood glucose (BG) and plasma insulin (PI) concentrations were measured at baseline (-30 min), and before (-10 min) and after 15, 30, 45, 60, 90 and 120 min after OGTT. The SP20 and SP40 significantly resulted in increased the PI secretion compared to SP0 following OGTT. The incremental area under the curves (iAUC) in PI was increased with SPI. The iAUC and peak response in BG were less for SP40 than SP20 and SP0, but not significantly between SP20 and SP0. We conclude that pre-meal consumption of SP40, but not SP20, improves glycemic control in young healthy subjects. Although the exaggerated insulin response to SPI should be mainly attributed to improvement of glycemic control, insulin independent mechanisms (e.g. delayed gastric emptying) might be also expected.
Soy Protein Research, Japan 18, 188-191, 2015.
Key words : dose response, insulin response, protein pre-load
The Effect of Soy Protein Isolate on Exercise -Induced Calpain Activation and Force Depression-
Keita KANZAKI*1, Daiki WATANABE2 and Masanobu WADA2
1Faculty of Health and Welfare Science, Okayama Prefectural University, Soja 719-1197
2Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashihiroshima 739-8521
ABSTRACT
In this study, we examined the effects of dietary soy protein isolate (SPI) on calpain activity and force output in rat skeletal muscle exposed to eccentric contractions (EC). Male Wistar rats were allowed free access to a 20% casein (control: CON) or SPI diet for 4 weeks. Following the feeding periods, the left anterior crural muscles were exposed to 200-repeated EC. The contralateral muscles were used as controls. Immediately after and 3 days following EC, extensor digitorum longus muscles were removed and used for force output measurements and biochemical analyses. In CON muscles, maximal calpain activity was unaltered immediately after EC, but elevated to 238% 3 days after EC, whereas in SPI muscles, it was not changed during 3 days of recovery. Immediately after EC, specific forces generated at 20 Hz were decreased to ~40% in both CON and SPI muscles. Following 3 days of recovery, the forces remained depressed in CON muscles, but recovered in SPI muscles. Functional impairment and degradation of sarcoplasmic reticulum Ca2+ release channel were observed in CON muscles, but not in SPI muscles 3 days after EC. These results suggest that dietary SPI may facilitate force recovery following EC by preventing calpain-mediated proteolysis of Ca2+ release channels.
Soy Protein Research, Japan 18, 192-197, 2015.
Key words : soy protein isolate, eccentric contraction, muscle damage, calpain, sarcoplasmic reticulum
Effects of Soy Protein Isolate on Neurogenesis and Mobility in the Intestine
Daisuke TORIGOE*
Laboratory of Laboratory Animal Science and Medicine, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818
ABSTRACT
Intake of isoflavone has been suggested to limit neurodegeneration and to exhibit neuropoietic effect in the central nerve system. However, there is almost no study on the effect of isoflavone on peripheral nerve system. In this study, we investigated the effects of Soy Protein Isolate (SPI) on neurogenesis and mobility of the intestine using Hirschsprung disease (HD) and hypoganglionosis (HG) model animals. First, we compared the ratio of aganglionosis between Hirschsprung disease model rat pups of which dams were fed a diet with/without SPI. We further examined the expression level of the neurogenesis markers in the intestine of 13.5 days post coitus rat. As a result, expression revel of Sox10 was significantly increased in the rat fed SPI feeding and the expression level of other two markers, PGP9.5 and Fgf13, were tended to be higher in SPI feeding group, however, SPI had no significant effect on neurogenesis of intestine. Next we investigated the effect on mobility of the intestine using HD model mice. The weight and number of feces tended to be lower in SPI feeding group. These results suggested that SPI have a potential to affect the neurogenesis and mobility of the intestine.
Soy Protein Research, Japan 18, 198-203, 2015.
Key words : isoflavone, Hirschsprung disease, aganglionosis, hypoganglionosis, neurogenesis
Search for Antibacterial Peptides Released from Soy Proteins in Fermented Soymilk
Kensuke ARAKAWA*, Kanako FUKUDOME, Naoki TOYOKAWA, Yoko OMORI and Taku MIYAMOTO
Department of Animal Science, Division of Agricultural and Life Science, Graduate School of Environmental and Life Science, Okayama University, Okayama 700-8530
ABSTRACT
Some antibacterial peptides released from milk proteins by cell-envelope proteinases (CEPs) of lactic acid bacteria have been already reported, but not yet from soy proteins. In this study, we aimed to search antibacterial peptides in soymilk fermented by Lactobacillus helveticus with various CEPs. Among 8 tested strains (nonbacteriocin producers) of Lb . helveticus , AK1244 and AK1245 were selected with antibacterial activity against Listeria monocytogenes VTU206 in cell-free supernatant (CFS) of the fermented soymilk. The activity was shown only at pH 4.5 or under. An optimal temperature of cultivation of both strains to produce antibacterial substances was 37℃, not 25, 30 and 42℃. Strain AK1244 produced the antibacterial substances during the stationary phase, whereas strain AK1245 did during the exponential and stationary phases. The antibacterial activity of the AK1244- and the AK1245-CFS was stable for heating. The activity of 4x CFS was comparatively resistant to enzymatic treatments using catalase and some proteinases, but α-chymotrypsin decreased the activity; suggesting that the CFS would include antibacterial short peptides in addition to nonproteinaceous antibacterial components such as lactic acid. The AK1244- and the AK1245-CFS had antibacterial activity against Escherichia coli (1 strain), Enterococcus sp. bacteria (2 strains) and Lactococcus lactis subsp. lactis (2 strains) as well as Lis . monocytogenes VTU206; whereas not against the other tested 14 strains of lactic acid bacteria. To separate antibacterial peptides from the CFS including the other antibacterial substances such as lactic acid, strain AK1245 was incubated with 5% (w/v) soy proteins, not soymilk, without fermentation (without production of lactic acid). 4x CFS of the suspension was analysed using C18-RP-HPLC, and then an antibacterial fraction which would include the antibacterial peptides was separated; but the antibacterial peptides have not been purified yet.
Soy Protein Research, Japan 18, 204-212, 2015.
Key words : antibacterial peptide, fermented soymilk, soy protein, Lactobacillus helveticus , cell-envelope proteinase
Chrono-nutritional Study for Anti-obesity Effect of Isoflavone
Yu TAHARA*1, 2, Mari KUWAHARA2 and Shigenobu SHIBATA2
1Waseda Institute of Advanced Study
2Laboratory of Physiology and Pharmacology, School of Advanced Science and Engineering, Waseda University, Tokyo 162-8480
ABSTRACT
Chrono-nutritional research is important to enhance the function of functional foods by considering the timing of consumption, because circadian clock system regulates many physiological processes with daily variations. Quercetin is one of functional flavonoids, and has antioxidant, anti-inflammatory, and anti-obesity effects. Here we show that quercetin prevents absorption of fats at the morning time but not at the evening time. In addition, daily morning intake of quercetin reduced fasting blood glucose and obesity-induced hyperinsulinemia. These results indicate that quercetin should be taken in the morning to prevent obesity.
Soy Protein Research, Japan 18, 213-220, 2015.
Key words : circadian clock, liver, obesity, quercetin
Antiproliferative Activity of Genistein via Inhibition of Cyclooxygenases
Yuki KAWAKAMI* and Yoshitaka TAKAHASHI
Department of Nutritional Science, Faculty of Health and Welfare Science, Okayama Prefectural University, Soja 719-1197
ABSTRACT
Cyclooxygenase (COX) is a rate limiting enzyme for the production of prostaglandins (PGs) and thromboxane from arachidonic acid. The enzyme catalyzes both bisdioxygenation of arachidonic acid (cyclooxygenase activity) producing PGG2 and conversion of PGG2 to PGH2 (PG hydroperoxidase activity). There are two isoforms, COX-1 which is constitutively expressed and COX-2 which is inducible. COX-1 plays an essential role in platelet aggregation, whereas COX-2 is necessary for ovulation and implantation. Both isoforms function coordinately in carcinogenesis and inflammation. Nonsteroidal anti-inflammatory drugs contribute to a reduction in mortality from colorectal cancer in individuals. Isoflavones are major soybean flavonoids showing various pharmacological effects. We previously showed that isoflavones inhibited the enzyme activities of COX isoforms and genistein inhibited COX-1 and COX-2 with IC50 values of 28μM and 110μM, respectively. We investigated inhibitory effects of genistein on the proliferation rate of the human colon carcinoma COLO320DM cells overexpressing COX-1 or COX-2. Genistein suppressed the cell growth and the DNA synthesis rate in the COXexpressing cells.
Soy Protein Research, Japan 18, 221-225, 2015.
Key words : cyclooxygenase; genistein; antiproliferative activity
Effects of Isoflavones Derived from Soy Beans on Tumor-Bearing Muscle
Katsuya HIRASAKA*1, Shinobu SAITO1, Saki YAMAGUCHI1, Riho MIYAZAKI1, Marie HARUNA2, Satoshi TAKESHITA1, Shigeto TANIYAMA1, Takeshi NIKAWA3 and Katsuyasu TACHIBANA1
1Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Nagasaki 852-8521
2Department of Human Environmental Sciences, School of Human Environmental Sciences, Mukogawa Woman's University, Nishinomiya 663-8558
3Department of Nutritional Physiology, Institute of Medical Nutrition, Tokushima University Medical School, Tokushima 770-8503
ABSTRACT
Proinflammatory cytokines produced by tumor contribute to a progression of muscle wasting. We have previously reported that isoflavones, such as genistein and daidzein, prevent the tumor necrosis factor-α-induced muscle atrophy in C2C12 myotubes. In this study, we examined the effect of dietary flavonoids on the wasting of muscle caused by cachexia. LLC (1 x 106) cells were injected subcutaneously into the right thighs of C57BL/6 mice. Mice continued to receive normal and isoflavone diet containing 0.4% soyaflavone HG until the termination of the experiment. The wet weight and cross sectional area in hindlimb muscles were examined at 3 weeks after tumor-bearing. There were no significant differences between normal and isoflavone diet in the intake of food and body weight. The wet weight in skeletal muscle of tumor-bearing mice significantly decreased, compared with that of vehicle injected mice. The isoflavone diet prevented the reduction of muscle wet weight and myofiber size. Therefore, dietary isoflavones suppress muscle wasting in tumor-bearing mice.
Soy Protein Research, Japan 18, 226-230, 2015.
Key words : muscle wasting, ubiquitin ligase, isoflavone diet
Research of Soyasapogenol Regulating Macrophage Activation for Cancer Therapy
Yukio FUJIWARA*1, Yoshihiro KOMOHARA1, Koji OHNISHI1, Tsuyoshi IKEDA2 and Motohiro TAKEYA1
1Department of Cell Pathology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto 860-8556
2Department of Natural Medicine, Faculty of Pharmaceutical Sciences of Sojo University, Kumamoto 860-0082
ABSTRACT
Tumor-associated macrophages (TAMs) polarized to the M2 phenotype promote tumor cell proliferation and are associated with a poor prognosis in patients. We previously revealed that corosolic acid and oleanolic acid, triterpenoid compounds, inhibit the M2 polarization of human monocyte-derived macrophages (HMDM). In the present study, we found that a crude extract of soybeans and soyasapogenol A and B, triterpenoid compounds, contained in soybeans significantly inhibited the expression of CD163, one of the phenotype markers of M2 macrophages, as well as suppressed the secretion of IL-10, one of the anti-inflammatory cytokines preferentially produced by M2 macrophages, thus suggesting that soyasapogenol A and B suppresses the M2 polarization of macrophages. Soyasapogenol A and B also inhibited the proliferation of U373 human glioblastoma cells and SaOS2 human osteosarcoma cells, and the activation of signal transducer and activator of transcription-3 (STAT3) in both human macrophages and tumor cells. These results indicate that soyasapogenol A and B regulates the macrophages activation and suppresses tumor cell proliferation by inhibiting STAT3 activation. Furthermore, oral administration of soyasapogenol B significantly suppressed both subcutaneous tumor development and lung metastasis in a LM8 tumor-bearing mouse model. Therefore, soyasapogenols may represent candidate agents that can be used for the prevention and/or treatment of various malignant tumors.
Soy Protein Research, Japan 18, 231-239, 2015.
Key words : macrophage, pSTAT3, soyasapogenol, osteosarcoma, glioma