Shigeru Katayama - Academia.edu (original) (raw)

Papers by Shigeru Katayama

Molecules

This study investigated the antioxidant and antimicrobial activities of six Thai edible plant lea... more This study investigated the antioxidant and antimicrobial activities of six Thai edible plant leaf extracts, including Cashew (CN), Chamuang (CM), Monpu (MP), Thurianthet (TT), Kradon (KD) and Pakliang (PL), extracted using ethanol extraction (EE), microwave-assisted extraction (MAE), and ultrasonic-assisted extraction (UAE). The leaf extracts were characterized for percentage yield, total phenolic content (TPC), total flavonoid content (TFC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and-ferric reducing antioxidant power (FRAP) activity, and antimicrobial activity against spoilage. MAE produced the highest percentage yields, among which MAE-extracted MP exhibited the highest yield. Furthermore, the highest TPC and TFC were obtained for MAE, with MAE-extracted KD and CN showing the highest TPC and TFC, respectively, among the samples. The highest DPPH and FRAP values were seen in MAE-processed CN, KD, and MP extracts. The inhibition zone of pathogenic bacteria, minimum inhibitory concent...

Nutrients

Buckwheat is an important pseudo-cereal crop worldwide. This study investigated whether long-term... more Buckwheat is an important pseudo-cereal crop worldwide. This study investigated whether long-term administration of buckwheat can suppress age-related cognitive decline in senescence-accelerated mouse prone 8 (SAMP8) mice. For 26 weeks, 18-week-old male SAMP8 mice were fed a standard diet containing 5% (w/w) buckwheat, Tartary buckwheat, wheat, or rice flour. In the Barnes maze and passive avoidance tests, mice fed buckwheat whole flour (BWF) showed improved cognitive performance compared to those fed a control diet, while no improvement was noticed in case of the other diets. Analysis of the gut microbiota showed that BWF and buckwheat outer flour administration increased the abundance of Lactococcus and Ruminiclostridium, respectively, at the genus level. The expression levels of brain-derived neurotrophic factor (BDNF), postsynaptic Arc and PSD95, and the mature neuronal marker NeuN in the hippocampus were increased after BWF administration, which was induced by the activation of...

Antioxidants

Recently, peptidic antioxidants have attracted much attention due to their promising applications... more Recently, peptidic antioxidants have attracted much attention due to their promising applications in the production of valuable functional food and nutraceuticals with health-promoting properties [...]

The 24 kDa protein (Fag e 1) in buckwheat is considered to be one of its major allergens. The pur... more The 24 kDa protein (Fag e 1) in buckwheat is considered to be one of its major allergens. The purpose of this study is to investigate the immunomodulatory effects of hypoallergenic Fag e 1 prepared by glycation with polysaccharide on mucosal allergenic responses in mice. Mannan-type-polysaccharide such as galactomannan (GalM), konjac glucomannan (KGM), and yeast glucomannan (YGM) showed attenuation of IL-4 and IL-17 production and elevation of IL-10 in cultured Peyer’s patch (PP) cells. The conjugate of Fag e 1 with GalM, KGM, or YGM was prepared using naturally occurring Maillard-type glycosylation. Dietary administration with Fag e 1-YGM conjugate for 8 weeks induced a significant reduction in Fag e 1-specific IgE and IgG1 levels and elevation in IgA level in sera and PP cells. A decrease in IL-4 and IL-17 and increase in IL-10 in PP cells were observed in the group of Fag e 1-YGM conjugate. Differentiation ratio of regulatory T cells (Treg) and T follicular helper cells in PP inc...

Antioxidants, 2021

Legumes such as soybean, chickpea, lentil, cowpea, and mung bean, are valuable sources of protein... more Legumes such as soybean, chickpea, lentil, cowpea, and mung bean, are valuable sources of protein with a high amino acid score and can provide bioactive peptides. This manuscript presents a review on legume-derived peptides, focusing on in vitro and in vivo studies on the potential antioxidative activities of protein hydrolysates and their characterization, amino acid sequences, or purified/novel peptides. The health implications of legume-derived antioxidative peptides in reducing the risks of cancer and cardiovascular diseases are linked with their potent action against oxidation and inflammation. The molecular weight profiles and amino acid sequences of purified and characterized legume-derived antioxidant peptides are not well established. Therefore, further exploration of legume protein hydrolysates is necessary for assessing the potential applications of antioxidant-derived peptides in the functional food industry.

Nutrients, 2019

The microbiota–gut–brain axis has attracted increasing attention in the last decade. Here, we inv... more The microbiota–gut–brain axis has attracted increasing attention in the last decade. Here, we investigated whether okara, a soybean by-product rich in dietary fiber, can attenuate cognitive impairment in senescence-accelerated mouse prone 8 (SAMP8) mice by altering gut microbial composition. Mice were fed either a standard diet, or a diet containing okara (7.5% or 15%, w/w) for 26 weeks. In the memory test, the 7.5% okara-fed mice showed a longer step-through latency and the 15% okara-fed mice had a short escape latency compared with control mice. The 15% okara-fed mice displayed decreased body weight, increased fecal weight, and altered cecal microbiota composition compared with the control group; however, there was no significant difference in the serum lactic acid and butyric acid levels among these mice groups. The 7.5% okara-fed mice had significantly higher NeuN intensity in the hippocampus compared with control mice. Furthermore, a decrease in inflammatory cytokine TNF-α and ...

Biochemical and Biophysical Research Communications, 2019

Intracellular cAMP activates Nampt promoter activity in 3T3-L1 cells. cAMP-induced C/EBPβ express... more Intracellular cAMP activates Nampt promoter activity in 3T3-L1 cells. cAMP-induced C/EBPβ expression stimulates Nampt promoter activity. C/EBPβ bound to promoter region of Nampt. NAMPT-mediated NAD synthesis is involved in adipogenesis of 3T3-L1 cells.

Nutrients, 2018

This study aimed to assess the suppressive effect of long-term diet supplementation with Lactobac... more This study aimed to assess the suppressive effect of long-term diet supplementation with Lactobacillus strains on cognitive decline in the senescence-accelerated mouse prone 8 (SAMP8) model. For 43 weeks, fourteen-week-old female SAMP8 mice were fed a standard diet containing 0.05% (w/w) Lactobacillus casei subsp. casei 327 (L. 327) or Lactobacillus paracasei K71 (L. K71) derived from rice grains and sake lees, respectively. SAMP8 mice that were fed a L. K71-supplemented diet had better cognitive performance compared with the control and L. 327 groups in the Barnes maze and passive avoidance tests. An ELISA analysis revealed that the levels of serotonin were elevated in the serum and brain tissue of L. K71-fed mice. The protein expression levels of brain-derived neurotrophic factor (BDNF), cAMP response element binding protein (CREB), and phosphorylated CREB were evaluated using western blot. Long-term administration of L. K71 resulted in increased protein expression of BDNF and CREB phosphorylation in the hippocampus. These results suggest that prolonged intake of a diet supplemented with a Lactobacillus strain derived from sake lees may prevent age-dependent cognitive decline by upregulating BDNF expression in the hippocampus.

Scientific Reports, 2018

Cyperenoic acid is a terpenoid isolated from the root of a medicinal plant Croton crassifolius wi... more Cyperenoic acid is a terpenoid isolated from the root of a medicinal plant Croton crassifolius with a wide range of biological activities. In this study, the effects of cyperenoic acid on osteoclast differentiation were investigated both in vitro and in vivo using receptor activator of nuclear factor-κB ligand (RANKL)-induced bone marrow-derived osteoclasts and senescence-accelerated mouse prone 6 (SAMP6). Cyperenoic acid significantly suppressed RANKL-induced osteoclast differentiation at the concentrations with no apparent cytotoxicity. The half maximum inhibitory concentration (IC50) for osteoclast differentiation was 36.69 μM ± 1.02. Cyperenoic acid treatment evidently reduced the expression of two key transcription factors in osteoclast differentiation, NFATc1 and c-Fos. Detailed signaling analysis revealed that cyperenoic acid did not affect MAPK pathways and canonical NF-κB pathway but impaired activation of p100/p52 in the non-canonical NF-κB pathway upon RANKL stimulation. ...

Molecules, 2019

The proteolytic digest of milk casein, known as casein phosphopeptide (CPP-III), exhibits diverse... more The proteolytic digest of milk casein, known as casein phosphopeptide (CPP-III), exhibits diverse biological activities, including calcium absorption and antioxidant activities. We hypothesized that the additional phosphorylation of this peptide can enhance its immunomodulatory activity such as suppression of allergy-associated cytokine and antigen-specific immune response. This study was conducted to assess whether oral intake of additionally phosphorylated CPP-III (P-CPP) attenuates ovalbumin (OVA)-induced IgE-mediated allergic reactions because of the additional phosphate groups. Female BALB/c mice were intraperitoneally sensitized with OVA twice at intervals of 14 days and then orally fed native CPP-III (N-CPP), P-CPP, and dephosphorylated CPP-III (D-CPP) for 6 weeks. Next, the mice were orally challenged with 50 mg of OVA. Oral administration of P-CPP suppressed total and specific IgE levels in the serum. Mice fed P-CPP exhibited low levels of OVA-specific IgG1 and increased OV...

Nutrition Research and Practice, 2019

BACKGROUND/OBJECTIVES: Alzheimer's disease is a neurodegenerative disease that induces symptoms s... more BACKGROUND/OBJECTIVES: Alzheimer's disease is a neurodegenerative disease that induces symptoms such as a decrease in motor function and cognitive impairment. Increases in the aggregation and deposition of amyloid beta protein (Aβ) in the brain may be closely correlated with the development of Alzheimer's disease. In this study, the effects of an adzuki bean extract on the aggregation of Aβ were examined; moreover, the anti-Alzheimer's activity of the adzuki extract was examined. MATERIALS/METHODS: First, we undertook thioflavin T (ThT) fluorescence analysis and transmission electron microscopy (TEM) to evaluate the effect of an adzuki bean extract on Aβ42 aggregation. To evaluate the effects of the adzuki extract on the symptoms of Alzheimer's disease in vivo, Aβ42-overexpressing Drosophila were used. In these flies, overexpression of Aβ42 induced the formation of Aβ42 aggregates in the brain, decreased motor function, and resulted in cognitive impairment. RESULTS: Based on the results obtained by ThT fluorescence assays and TEM, the adzuki bean extract inhibited the formation of Aβ42 aggregates in a concentration-dependent manner. When Aβ42-overexpressing flies were fed regular medium containing adzuki extract, the Aβ42 level in the brain was significantly lower than that in the group fed regular medium only. Furthermore, suppression of the decrease in motor function, suppression of cognitive impairment, and improvement in lifespan were observed in Aβ42-overexpressing flies fed regular medium with adzuki extract. CONCLUSIONS: The results reveal the delaying effects of an adzuki bean extract on the progression of Alzheimer's disease and provide useful information for identifying novel prevention treatments for Alzheimer's disease.

Biochimica et biophysica acta, Dec 1, 2017

Theobromine, a methylxanthine derived from cacao beans, reportedly has various health-promoting p... more Theobromine, a methylxanthine derived from cacao beans, reportedly has various health-promoting properties but molecular mechanism by which effects of theobromine on adipocyte differentiation and adipogenesis remains unclear. In this study, we aimed to clarify the molecular mechanisms of the anti-adipogenic effect of theobromine in vitro and in vivo. ICR mice (4week-old) were administered with theobromine (0.1g/kg) for 7days. Theobromine administration attenuated gains in body and epididymal adipose tissue weights in mice and suppressed expression of adipogenic-associated genes in mouse adipose tissue. In 3T3-L1 preadipocytes, theobromine caused degradation of C/EBPβ protein by the ubiquitin-proteasome pathway. Pull down assay showed that theobromine selectively interacts with adenosine receptor A1 (AR1), and AR1 knockdown inhibited theobromine-induced C/EBPβ degradation. Theobromine increased sumoylation of C/EBPβ at Lys133. Expression of the small ubiquitin-like modifier (SUMO)-sp...

Archives of biochemistry and biophysics, Jan 15, 2018

Adipose tissues in obese individuals are characterized by a state of chronic low-grade inflammati... more Adipose tissues in obese individuals are characterized by a state of chronic low-grade inflammation. Pre-adipocytes and adipocytes in this state secrete pro-inflammatory adipokines, such as interleukin 6 (IL-6), which induce insulin resistance and hyperglycemia. Theophylline (1,3-dimethylxanthine) exerts anti-inflammatory effects, but its effects on pro-inflammatory adipokine secretion by pre-adipocytes and adipocytes have not been examined. In this study, we found that theophylline decreased IL-6 secretion by 3T3-L1 pre-adipocytes and mouse-derived primary pre-adipocytes. The synthetic glucocorticoid dexamethasone (DEX) induced IL-6 expression in 3T3-L1 pre-adipocytes, and this effect was suppressed by theophylline at the mRNA level. Knockdown of CCAAT/enhancer binding protein (C/EBP) δ inhibited DEX-induced IL-6 expression, and theophylline suppressed C/EBPδ expression. Furthermore, theophylline suppressed transcriptional activity of the glucocorticoid receptor (GR) through suppre...

Protein science : a publication of the Protein Society, Oct 20, 2016

The mannitol transporter enzyme II(Mtl) of the bacterial phosphotransferase system is a multi-dom... more The mannitol transporter enzyme II(Mtl) of the bacterial phosphotransferase system is a multi-domain protein that catalyzes mannitol uptake and phosphorylation. Here we investigated the domain association between cytosolic A and B domains of enzyme II(Mtl) , which are natively connected in Escherichia coli, but separated in Thermoanaerobacter tengcongensis. NMR backbone assignment and residual dipolar couplings indicated that backbone folds were well conserved between the homologous domains. The equilibrium binding of separately expressed domains, however, exhibited ∼28-fold higher affinity compared to the natively linked ones. Phosphorylation of the active site loop significantly contributed to the binding by reducing conformational dynamics at the binding interface, and a few key mutations at the interface were critical to further stabilize the complex by hydrogen bonding and hydrophobic interactions. The affinity increase implicated that domain associations in cell could be maint...

$Research paper thumbnail of Improvement of surface functionalities, including allergenicity attenuation, of whole buckwheat protein fraction by maillard-type glycation with dextran$

Preventive nutrition and food science, 2014

The purpose of the current study was to determine the effects of the introduction of polysacchari... more The purpose of the current study was to determine the effects of the introduction of polysaccharide chains onto the molecular surface of buckwheat proteins on buckwheat protein surface functionality. The whole buckwheat protein fraction (WBP) was prepared using 50 mM phosphate buffer (pH 7.5) containing 0.5 M NaCl and covalently linked with 6 kDa, 17.5 kDa, 40 kDa, 70 kDa, or 200 kDa dextran by Maillard-type glycation through controlled dry-heating at 60°C and 79% relative humidity for two weeks. Conjugation with 40 kDa dextran improved the water solubility and emulsifying properties of WBP without causing a serious loss of available lysine; 84.9% of the free amino groups were conserved. In addition, we found that the introduction of dextran chains onto the molecular surfaces of WBP attenuated the antigenicity of WBP.

Journal of Agricultural and Food Chemistry, 2014

Food allergies are attributed to an imbalance in immune response to ubiquitous antigens. A previo... more Food allergies are attributed to an imbalance in immune response to ubiquitous antigens. A previous study demonstrated that mannose glycation (mannosylation) of ovalbumin decreased allergenicity in vivo. The proposed research targets mannosylation of various common allergens that may help prevent food allergy. Balb/c mice (n = 8) were sensitized toxin egg white, peanut, and whey and treated with mannosylated forms of the test antigens. Glucosylated peanut and cholera toxins were used as controls. Allergic status was assessed as clinical signs, serum histamine, mouse mast cell protease (MMCP), antibody activity, cytokines, and T regulatory cells (T-regs). Significant preventative effects were observed with mannosylated egg white treatment such as reduced clinical signs, histamine, MMCP, specific G, G1, and E antibody activities, and IL-4 and increased IL-10 and CD25(+) Foxp3(+) cells. Other groups did not differ significantly. It was concluded that mannosylated egg white provides a powerful tool to prevent allergic phenotypes with possible relevance to control human egg allergy.

Journal of the Korean Society for Applied Biological Chemistry, 2014

Chlorogenic acid (CGA) is a natural chemical ester composed of caffeic acid and (-)-quinic acid, ... more Chlorogenic acid (CGA) is a natural chemical ester composed of caffeic acid and (-)-quinic acid, and is further metabolized into active compounds in the living body. Here, we aimed to provide fundamental information on the antimicrobial action of CGA and related compounds against the Gram-negative bacterium Escherichia coli IFO 3301. Bacteriostatic effects were assessed by spectrophotometry, and bactericidal effects were determined by enumerating viable cells on MacConkey agar plates. CGA and related compounds exhibited specific antimicrobial activity and corresponding reduction in log survival ratio, in which ferulic, isoferulic, benzoic, and hydroxybenzoic acids exhibited obvious antimicrobial activity against E. coli. In a timekill assay, it was observed that bactericidal effects were associated with treatment time, temperature, and dose. A reduction in log survival ratio was observed at low pH as well as under thermal stress condition. Thus, we demonstrated that CGA and related compounds have not only bacteriostatic effects but also bactericidal effects. Keywords bactericidal effect • bacteriostatic effect • chlorogenic acid • polyphenol Materials and Methods Materials. Dimethyl sulfoxide, quinic acid, and ferulic acid were purchased from WAKO Pure Chemical Industries Ltd. (Japan). Luria broth (LB), and benzoic, hydroxybenzoic, caffeic, and hippuric acids were purchased from SIGMA-ALDRICH (Japan).

Beneficial Microbes, 2014

Kale, a cultivar of Brassica oleracea, has attracted a great deal of attention because of its hea... more Kale, a cultivar of Brassica oleracea, has attracted a great deal of attention because of its health-promoting effects, which are thought to be exerted through modulation of the intestinal microbiota. The present study was performed to investigate the effects of kale ingestion on the gastrointestinal microbial ecology of mice. 21 male C57BL/6J mice were divided into three groups and housed in a specific pathogen-free facility. The animals were fed either a control diet or experimental diets supplemented with different commercial kale products for 12 weeks. Contents of the caecum and colon of the mice were processed for the determination of active bacterial populations by a bacterial rRNA-based quantification method and short-chain fatty acids by HPLC. rRNAs of Bacteroides-Prevotella, the Clostridium coccoides-Eubacterium rectale group, and Clostridium leptum subgroup constituted the major fraction of microbiota regardless of the composition of the diet. The ratio of Firmicutes to Ba...

Journal of the Science of Food and Agriculture, 2007

BACKGROUND: Food protein‐derived peptides with antioxidant activity have great potential for use ... more BACKGROUND: Food protein‐derived peptides with antioxidant activity have great potential for use as natural antioxidants in food products. However, neither the structure–activity relationship nor the antioxidant mechanism of peptides is fully understood. Egg yolk phosvitin has been acknowledged to have strongly antioxidant protein owing to its highly phosphorylated form. In this study the antioxidant activities of tryptic digests of hen egg yolk phosvitin (PPPs), which were prepared by partial dephosphorylation and subsequent hydrolysis by trypsin, were compared with that of intact phosvitin.RESULTS: Compared with intact phosvitin, PPPs exhibited distinctly stronger capability of inhibiting lipid oxidation in a linoleic acid system and more efficient radical‐scavenging activity on 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) free radicals. However, the chelating capability of PPPs on iron(II) was weaker than that of intact phosvitin. The strong antioxidant activity of PPPs can be mainly att...

Food Chemistry, 2013

Apple polyphenol extract (AP) and procyanidin contained in AP were investigated for their immunom... more Apple polyphenol extract (AP) and procyanidin contained in AP were investigated for their immunomodulatory effects using THP-1-derived human dendritic cells (TDDCs). The expression levels of HLA-DR (MHC class II) and CD86 (costimulatory molecule) were measured as an indicator of antigen presentation in TDDCs. A significant decrease in HLA-DR expression was observed in the AP and fractionated procyanidin-treated cells in the presence of ovalbumin (OVA), but no effect on CD86 expression was observed. The uptake of OVA was not inhibited by AP treatment, and the gene expression of membrane-associated RING-CH ubiquitin E3 ligase, MARCH1, was up-regulated by AP treatment. It can therefore be presumed that AP suppresses HLA-DR expression via the ubiquitin-proteasome pathway. Furthermore, the upregulation of IL-12 and TNF-a was found in the procyanidin trimers-treated cells in the presence of OVA. These results suggest that apple polyphenols would be an effective factor for the development of immunomodulatory agents with suppressive effects of antigen presentation.