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Inhibiting starch hydrolysis into sugar could reduce postprandial blood glucose elevation and contribute to diabetes prevention. Here, both buckwheat and wheat albumin that inhibited mammalian α-amylase in vitro suppressed blood glucose level elevation after starch loading in vivo, but it had no effect after glucose loading. In contrast to the non-competitive inhibition of wheat α-amylase inhibitor, buckwheat albumin acted in a competitive manner. Although buckwheat α-amylase inhibitor was readily hydrolysed by digestive enzymes, the hydrolysate retained inhibitory activity. Together with its thermal stability, this suggests its potential use in functional foods that prevent diabetes.

Wheat allergy is a serious disease because it is difficult to be outgrown and sometimes induces anaphylaxis. Gliadin, a major allergen in wheat, deamideted by cation-exchange resins (DG) had low allergenicity not only in vitro but also in vivo. As the allergen-specific immunotherapy, a treatment for allergies, hold a risk of severe allergic reaction, the deamidated gliadin that has low allergenicity would provide an effective tool for treatment of wheat allergy. Thus, we examined if DG would induce oral tolerance using a mouse model of wheat allergy. Mice sensitized with untreated gliadin (UG) by intraperitoneal injection were orally administered with DG every other day for four weeks, and then UG was orally challenged to induce systemic anaphylaxis. Repeated oral administration of DG suppressed allergic reaction induced by UG challenge, and dramatically increased the number of regulatory T cells indicating deamidated gliadin induced oral tolerance.

Alcoholic beverages are enjoyed together with meals worldwide, but their excessive intake is associated with an increased risk of various diseases. We investigated whether S-allyl-L-cysteine sulfoxide (ACSO), a sulfuric odor precursor of garlic, suppresses elevation in plasma ethanol concentration by accelerating ethanol metabolism and preventing ethanol absorption from the gut in rats. ACSO and garlic extract with a high ACSO content (Garlic-H) suppressed elevation in concentrations of ethanol and acetaldehyde in plasma and promoted the activities of alcohol dehydrogenase and aldehyde dehydrogenase. However, ACSO and Garlic-H did not affect plasma acetate so much. Furthermore, we examined the change in plasma ethanol concentration by injecting ACSO or Garlic-H into the ligated stomach or jejunum together with ethanol solution. ACSO and Garlic-H suppressed the absorption of ethanol from the stomach and jejunum, but suppression in the jejunum was less than in the stomach. In conclusion, ACSO inhibits ethanol absorption and accelerates ethanol metabolism. A garlic odor precursor suppresses blood ethanol elevation.

凍結豚ロース肉を従来の4℃空気解凍して製造したロースハムと，あらかじめ調製した塩漬液に凍結状態で直接投入して解凍と同時に塩漬して製造したロースハムの品質と歩留りの比較を試みた．1． 解凍時間は凍結肉が少量の解凍では空気解凍と塩漬解凍に差は無く，凍結肉の量が増すと塩漬解凍時間は長時間を要した．2． ロースハムの水分含量は空気解凍法よりも塩漬解凍法の方が約5％高い値を示した．食塩含量は塩漬解凍法よりも空気解凍法の方が0.2％高い値を示した．3． 塩漬終了後通常の方法で製造したロースハムの製品歩留りは空気解凍法では87.9％であるのに対して塩漬解凍法では95.3％であり7.4％増加した．また，凍結ロース3本（12kg）を10日間塩漬・熟成させた後に製造したロースハムの製品歩留りは，空気解凍法では84.4％であり，塩漬解凍法では91.6％となり7.2％の増加が認められた．4． ロースハムの官能検査においては香り，色調，軟らかさ，塩味の4項目にはほとんど差が認められなかった．以上のことから塩漬解凍法で解凍し製造する方法が設備や経費の面からかなりの経済効果が期待できる．また，環境への負担が軽減されることが示唆された．

Inhibiting starch hydrolysis into sugar could reduce postprandial blood glucose elevation and contribute to diabetes prevention. Here, both buckwheat and wheat albumin that inhibited mammalian &alpha, amylase in vitro suppressed blood glucose level elevation after starch loading in vivo, but it had no effect after glucose loading. In contrast to the non-competitive inhibition of wheat &alpha, amylase inhibitor, buckwheat albumin acted in a competitive manner. Although buckwheat &alpha, amylase inhibitor was readily hydrolysed by digestive enzymes, the hydrolysate retained inhibitory activity. Together with its thermal stability, this suggests its potential use in functional foods that prevent diabetes.

ジャンボリーキ鱗片から得られた泡粉末と比較のために鱗片末およびクルクミンを用いてGaINにより誘発される急性肝障害およびEtOHによって惹起される慢性肝障害モデルラットに対する影響を調べた．また同時に，推定関与成分として生鱗片からサポニンの単離・同定を試みた．その結果，ジャンボリーキの泡粉末および鱗片末は，GaIN，およびEtOHのラットへの投与実験において急性肝障害時の機能低下を抑制すること，またアルコール吸収を抑制することにより慢性肝障害を予防することを明らかにした．そして，その関与成分として既知のステロイドサポニンである（25R）-spirost-5-ene-2α,3β-diol-3-O-｛O-β-D-glucopyranosyl-(1→2)-O-[β-D-xylopyranosyl-(1→3)]-O-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside｝，（C50H80O23，MW : 1048），カラタビオサイドAの存在を提示した．

Plasmin is an essential enzyme located in the pericellular microenvironment of liver cells during liver regeneration. Previously, we reported that liver regeneration ability was significantly increased in alpha2-antiplasmin gene knockout mice as compared to wild-type mice, but it was significantly decreased in plasminogen knockout mice, or Plg/alpha2-antiplasmin gene knockout mice. The present study aimed to demonstrate direct interaction between plasminogen and mouse hepatocytes in the process of liver regeneration. Using the isolated hepatocytes from mice we analyzed following subjects: binding capacity of plasminogen to hepatocytes, plasminogen activation in the presence of hepatocytes, and proliferation ability of hepatocytes cocultured with liver nonparenchymal cells. The isolated hepatocytes from plasminogen wild-type mice bound to immobilized plasminogen. The mouse hepatocytes enhanced plasminogen activation, and impaired the inhibitory effect of alpha2-antiplasmin. The proliferation ability of hepatocytes after liver injury was studied. In plasminogen wild-type and plasminogen knockout mice, the hepatocytes cocultured with nonparenchymal cells, which were obtained from mice without CCl4 injection, showed similar proliferation abilities. On the contrary, the proliferation ability of hepatocytes cocultured with nonparenchymal cells, which were obtained from CCl4-treated plasminogen knockout mice, was significantly impaired as compared to wild-type mice. These results indicate that the plasminogen-plasmin system on the surface of mouse hepatocytes plays an important role in liver regeneration.

A simple method for the isolation of the bioactive compound alliin from garlic, as well as a method for the synthesis of diastereomerically pure alliin and allo-alliin on a preparative laboratory scale, was developed. The absolute configuration of the sulfur atom in alliin and allo-alliin was assigned on the basis of enzyme reactivity, optical rotatory dispersion, and circular dichroism analyses. A comparison of the results from these analyses, in combination with an X-ray diffraction study on a protected allo-alliin derivative, revealed S and R configurations of the sulfur atoms in alliin and allo-alliin, respectively. In addition, the same (1)H NMR spectrum was observed for synthetic and natural alliin. The absolute configuration of natural alliin was assigned for the first time on the basis of the NMR spectrum and X-ray coordinates.

Phytate-removed and deamidated soybean β-conglycinin (PrDS) prepared by ion-exchange resins was supplemented to be 4% in the diet administered to ovariectomized rats to investigate its preventive effect on osteoporosis. The apparent calcium absorption rate decreased following ovariectomy and was not replenished by oral administration of phytate-removed soybean β-conglycinin (PrS) or casein. On the other hand, administration of PrDS restored the calcium absorption rate to the same level as the sham group. Markers of bone resorption, such as serum parathyroid hormone (PTH) and urinary deoxypyridinoline (DPD), increased, and the bone mineral density and breaking stress decreased following ovariectomy. However, PrDS supplementation suppressed the changes caused by the decrease in calcium absorption from the small intestine. Therefore, PrDS supplementation shows promise for the prevention of postmenopausal osteoporosis.

Background/aims: Liver regeneration after partial hepatectomy is thought to be regulated by various molecules including the components of the plasminogen activator (PA)-plasmin system. We have examined the role of fibrinolytic factors, i.e., tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA), and their substrate, plasminogen, in the proliferation of hepatocytes in primary culture. Methods: Hepatocyte and nonparenchymal liver cells were isolated from Wistar strain rat by a method perfusing the liver with collagenase. DNA synthesis was assessed by measuring the incorporation of [3H]-thymidine into cellular DNA fraction. tPA, uPA and type-1 plasminogen activator inhibitor (PAI-1) gene expressions were measured by Northern blotting. PA activity was measured by fibrin/agarose plate method. Results: Cellular density-dependent DNA synthesis was observed in the primary cultured hepatocytes; DNA synthesis was lower at high cell density (1.0×105 cells/cm2) than that at low cell density (0.2×105 cells/cm2). DNA synthesis in the hepatocytes cultured at a low cell density was increased by co-culture with nonparenchymal liver cells. Under these growth-stimulated culture conditions, tPA and uPA mRNAs were induced and up-regulated. On the contrary, the PAI-1 mRNA level was decreased under these conditions, and total PA activity was augmented accordingly. The synthetic plasmin inhibitor tranexamic acid, a competitive inhibitor for the plasmin molecule, and PASI-535, a plasmin active center-directed inhibitor, both suppressed hepatocyte proliferation in a dose-dependent fashion. Anti-plasmin antibody also suppressed hepatocyte proliferation. Conclusions: The up-regulation of PA activity for ensuring plasmin activity should be an important mechanism in the proliferation of hepatocytes.

Gliadin is the principal allergen of wheat-dependent exercise-induced anaphylaxis (WDEIA). The primary structure of IgE-binding epitopes in wheat gliadin includes tandem sequencing sites of glutamine residues. Therefore, deamidation would be an effective approach to reduce the allergenicity of wheat proteins. In our previous study, we deamidated wheat gliadin without causing peptide-bond hydrolysis or polymerization by use of carboxylated cation-exchange resins, and we found that the deamidated gliadin scarcely reacted with the sera of patients radioallergosorbent test (RAST)-positive to wheat. In this study, we examined the allergenicity of deamidated gliadin in a mouse model of wheat-gliadin allergy. Oral administration of deamidated gliadin to gliadin-sensitized mice suppressed enhancement in intestinal permeability, serum allergen level, serum allergen-specific IgE level, mast-cell-surface expression of FceRI, and serum and intestinal histamine levels. Our results indicate that gliadin deamidated with no peptide-bond hydrolysis by cation-exchange resins has low allergenicity even under in vivo conditions.

Acrolein (Acr) is a ubiquitous environmental contaminant; it also can be generated endogenously by lipid peroxidation. Acr contains a carbonyl group and an olefinic double bond; it can react with many cellular molecules including amino acids, proteins and nucleic acids. In this review article we focus on updating information regarding: (i) Acr-induced DNA damage and methods of detection, (ii) repair of Acr-DNA damage, (iii) mutagenicity of Acr-DNA adducts, (iv) sequence specificity and methylation effect on Acr-DNA adduct formation and (v) the role of Acr in human cancer. We have found that Acr can inhibit DNA repair and induces mutagenic Acr-dG adducts and that the binding spectrum of Acr in the p53 gene in normal human bronchial epithelial cells is similar to the p53 mutational spectrum in lung cancer. Since Acr-DNA adduct has been identified in human lung tissue and Acr causes bladder cancer in human and rat models, we conclude that Acr is a major lung and bladder carcinogen, and its carcinogenicity arises via induction of DNA damage and inhibition of DNA repair.

A novel simple method using liquid chromatography/time-of-flight mass spectrometry (LC/TOF-MS) and LC/UV was established for the quantification of saponins in an extract from green tea leaves. The amount of saponins in a fraction with high in vitro antihypercholesterolemic activity, Fr2-3, was determined to be 72%. An in vivo experiment showed that the addition of 0.5% Fr2-3 to a high-cholesterol diet suppressed the increase in serum cholesterol levels in rats. Fr2-3 induced a decrease in the liver cholesterol and triglyceride levels and an increase in the fecal excretion of cholesterol. These results indicate tea-leaf saponins to be the active components in Fr2-3 and that these saponins exhibited antihypercholesterolemic activity by inhibiting cholesterol absorption in the intestines.

Purpose of review Congestive heart failure is increasing in prevalence and represents a major public health problem. The syndrome of advanced heart failure often includes muscle wasting, commonly termed cardiac cachexia, which is a predictor of poor outcome. Mechanisms of cardiac cachexia are poorly understood, but there is recent evidence that increased angiotensin II, interacting with the insulin-like growth factor-1 system, plays an important role. Recent findings In animals, angiotensin II produces weight loss through a pressor-independent mechanism, accompanied by decreased levels of circulating and skeletal muscle insulin-like growth factor-1 and increased mRNA levels of the ubiquitin ligases atrogin-1 and Muscle RING finger-1 in skeletal muscle. Reduced insulin-like growth factor-1 action in muscle leads to increased proteolysis, through the ubiquitin-proteasome pathway, and increased apoptosis. These changes are blocked by muscle-specific expression of insulin-like growth factor-1, likely to be via the Akt/mTOR/p70S6K signaling pathway. Summary The link between insulin-like growth factor-1, the ubiquitin-proteasome pathway, and angiotensin II effects has widespread clinical implications for the understanding of mechanisms of catabolic conditions. Therapeutic interventions targeting cross-talk mechanisms between angiotensin II and insulin-like growth factor-1 effects could provide new approaches for the treatment of muscle wasting.

The isolated rat hepatocytes inoculated onto the surface of positively charged culture dishes are anchored initially and then begin to migrate and aggregate gradually to form multicellular spheroids detached from the dish. We studied the roles of fibrinolytic factors in the spheroid formation. The fibrinolytic factors, tissue-type plasminogen activator (tPA), and urokinase-type plasminogen activator (uPA), were increased in the course of spheroid formation. Then, we introduced fibrinolytic inhibitors into the spheroid cultures to determine functions of fibrinolytic factors. Plasmin inhibitor inhibited markedly the spheroid formation. Interestingly, the anti-plasmin antibody showed different effect depending on the timing of its administration. In summary, we demonstrated for the first time that induction of PAs and ensuing plasmin generation on the cell surface play important roles in hepatocyte spheroid formation, and that plasmin is involved in the different processes such as cell migration and cell detachment in the formation of hepatocyte spheroid.

The liver produces a variety of proteins including plasminogen. Plasminogen is pro-enzyme that is converted into plasmin by plasminogen activator. Plasmin has a broad substrate spectrum and participates in several biological processes, such as fibrinolysis, tissue remodeling, cell migration, angiogenesis and embryogenesis. In the present study, the regulation of plasminogen expression in mouse hepatocytes was investigated in the primary culture system. Expression level of plasminogen mRNA in the culture at the low cell density condition (0.2 x 10(5) cells / cm(2)) was compared with that at the high cell density condition (1.0 x 10 (5) cells / cm(2)). In the low cell density culture, the expression level of plasminogen mRNA decreased by a time-dependent manner. However, mRNAs for albumin and alpha(2)-antiplasmin were not influenced by the low cell density culture. On the other hand, in the high cell density culture, plasminongen mRNA expressed constantly as well as albumin and alpha(2)-antiplasmin mRNAs. Thus, the decrease in plasminogen mRNA expression could specifically occur when the density of hepatocytes was low. The down-regulation of plasminogen mRNA in the low cell density culture is not observed in the presence of cycloheximide, suggesting that the de novo protein synthesis is required for the regulatory mechanism. These findings indicate that the expression of plasminogen mRNA from hepatocyte is dependent on the cell density and the stimulation by cell-cell contact may be an important factor for the constitutive expression of plasminogen gene in hepatocytes.

Liver regeneration after partial hepatectomy is thought to be regulated by various molecules including the components of the plasminogen activator (PA)-plasmin system [1]. This system has pleiotropic effects, being active in fibrin and ECM degradation, in growth factor activation, and in the integrin signaling in cell proliferation [2,3].

Background/Aims: The plasminogen activator (PA)–plasmin system is primarily involved in fibrinolysis, but is also in the patho/physiological events in which breakdown of extracellular matrices is evoked topically. In this present study, we examined the expression of fibrinolytic factors, tissue-type PA (t-PA) and Type 1 PA inhibitor (PAI-1), in acute liver injury. Methods: Acute liver injury was produced in rats by the intraperitoneal administration of carbon tetrachloride (CCl 4 ). Plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities were measured to verify the hepatocellular damage. t-PA and PAI-1 gene expressions were measured by Northern blotting, and the cell type(s) expressing these genes was identified by in situ hybridization. t-PA and PAI-1 levels were measured by enzyme-linked immunosorbent assay (ELISA). Results: A single intraperitoneal administration of CCl 4 caused severe acute parenchymatous liver injury. Both t-PA and PAI-1 gene expressions were induced by the acute liver injury, and plasma t-PA and PAI-1 concentrations were also increased. In situ hybridization studies demonstrated that the hepatocytes were the cells expressing t-PA and PAI-1 genes during the acute liver injury. t-PA was also augmented in the bile, whereas PAI-1 was decreased there. Conclusions: t-PA and PAI-1 gene expressions are induced in the hepatocytes of rats with acute liver injury. These fibrinolytic factors induced by liver injury may play important roles in liver regeneration.