Propagule Powder of Japanese Yam (Dioscorea Japonica) Reduces High-Fat Diet-Induced Metabolic Stress in Mice through the Regulation of Hepatic Gene Expression.

SCOPE: Japanese yam propagules are supposed to have high potential as a functional food. However, there are almost no studies examining their physiological function. This study aims to elucidate the physiological function of Japanese yam propagules that are heated, freeze-dried, and powdered. METHODS AND RESULTS: A high-fat diet with Japanese yam propagules is administered to mice for 4 weeks. High-fat loading induces a decline in respiratory quotient, and a high-fat diet with propagules reduces it more. This result suggests that propagules increase fat oxidation, indicating fat utilization. The hepatic transcriptome is analyzed using a DNA microarray. Some of the genes affected by high-fat loading are reversed by simultaneous ingestion of propagules. Such genes are mainly involved in the immune system and fat metabolism. High-fat loading induces hepatic inflammation, which is repressed by simultaneous ingestion of propagules. For lipid metabolism, propagules repress an increase in cholesterol biosynthesis and catabolism by high-fat loading. Regarding carbohydrate metabolism, propagules decrease glycolysis and glycogen synthesis and increase gluconeogenesis. Moreover, amino acids are converted into pyruvate and then used for gluconeogenesis. CONCLUSION: Propagules act to delay the occurrence of hepatic disease by suppressing carbohydrate and fat metabolism disorders in high-fat loaded mice.

Quantitative deviating effects of maple syrup extract supplementation on the hepatic gene expression of mice fed a high-fat diet.

SCOPE: Maple syrup contains various polyphenols and we investigated the effects of a polyphenol-rich maple syrup extract (MSXH) on the physiology of mice fed a high-fat diet (HFD). METHODS AND RESULTS: The mice fed a low-fat diet (LFD), an HFD, or an HFD supplemented with 0.02% (002MSXH) or 0.05% MSXH (005MSXH) for 4 weeks. Global gene expression analysis of the liver was performed, and the differentially expressed genes were classified into three expression patterns; pattern A (LFD < HFD > 002MSXH = 005MSXH, LFD > HFD < 002MSXH = 005MSXH), pattern B (LFD < HFD = 002MSXH > 005MSXH, LFD > HFD = 002MSXH < 005MSXH), and pattern C (LFD < HFD > 002MSXH < 005MSXH, LFD > HFD < 002MSXH > 005MSXH). Pattern A was enriched in glycolysis, fatty acid metabolism, and folate metabolism. Pattern B was enriched in tricarboxylic acid cycle while pattern C was enriched in gluconeogenesis, cholesterol metabolism, amino acid metabolism, and endoplasmic reticulum stress-related event. CONCLUSION: Our study suggested that the effects of MSXH ingestion showed (i) dose-dependent pattern involved in energy metabolisms and (ii) reversely pattern involved in stress responses.

Coordinated regulation of hepatic and adipose tissue transcriptomes by the oral administration of an amino acid mixture simulating the larval saliva of Vespa species.

BACKGROUND: VAAM is an amino acid mixture that simulates the composition of Vespa larval saliva. VAAM enhanced physical endurance of mice and have been used by athletes as a supplementary drink before exercise. However, there is no information on the effect of VAAM on the physiology of freely moving animals. The purpose of this study was to obtain information about the VAAM-dependent regulation of liver and adipose tissue transcriptomes. RESULTS: Mice were orally fed a VAAM solution, an amino acid mixture mimicking casein hydrolysate (CAAM) or water under ad libitum feeding conditions for 5 days. Comparisons of the hepatic transcriptome between VAAM-, CAAM-, and water-treated groups revealed a VAAM-specific regulation of the metabolic pathway, i.e., the down-regulation of glycolysis and fatty acid oxidation and the up-regulation of polyunsaturated fatty acid synthesis and glucogenic amino acid utilization. Similar transcriptomic analyses of white and brown adipose tissues (WAT and BAT, respectively) indicated the up-regulation of phospholipid synthesis in WAT and the negative regulation of cellular processes in BAT. Because the coordinated regulation of tissue transcriptomes implied the presence of upstream signaling common to these tissues, we conducted an Ingenuity Pathways Analysis. This analysis showed that estrogenic and glucagon signals were activated in the liver and WAT and that beta-adrenergic signaling was activated in all three tissues. CONCLUSIONS: We found that VAAM ingestion had an effect on multiple tissue transcriptomes of freely moving mice. Utilization of glycogenic amino acids may have been activated in the liver. Fatty acid conversion into phospholipid, not to triacylglycerol, may have been stimulated in adipocytes contrasting that a little effect was observed in BAT. Analysis of upstream factors revealed that multiple hormonal signals were activated in the liver, WAT, and BAT. Our data provide some clues to understanding the role of VAAM in metabolic regulation.

Bacillus cereus Response to a Proanthocyanidin Trimer, a Transcriptional and Functional Analysis.

Proanthocyanidins are abundant in peanut skin, and in this study, the antibacterial effects of a peanut skin extract (PSE) against food-borne bacteria were investigated to find its minimum inhibitory concentration. Food-borne gram-positive bacteria, and in particular Bacillus cereus, was more sensitive to PSE. In particular, the inhibitory activity of epicatechin-(4ߠ→ 6)-epicatechin-(2ߠ→ O→7, 4ߠ→ 8)-catechin (EEC), a proanthocyanidin trimer from peanut skin, against B. cereus was stronger than that of procyanidin A1, a proanthocyanidin dimer. DNA microarray analysis of B. cereus treated with EEC was carried out, with a finding that 597 genes were significantly up-regulated. Analysis of the up-regulated genes suggested that EEC disrupted the normal condition of the cell membrane and wall of B. cereus and alter its usual nutritional metabolism. Moreover, treatment of B. cereus with EEC inhibited glucose uptake, suggesting that EEC affects the cell-surface adsorption.

Administration of a maple syrup extract to mitigate their hepatic inflammation induced by a high-fat diet: a transcriptome analysis.

Effects of the administration of maple syrup extract (MSX) on hepatic gene expression were investigated in mice fed a high-fat diet. Gene annotation enrichment analysis based on gene ontology revealed some changes in the expression of genes related to lipid metabolism and the immune response in MSX-fed mice. Detailed analysis of these data indicated that MSX ingestion mitigates hepatic inflammation.

Characterization of the quality of imbibed soybean at an early stage of pre-germination for the development of a new protein food item.

This was a pilot study carried out to develop a new protein food item from imbibed soybean before germination. It identified the significance of a short stage after imbibition and before germination, and that vitamin C production was activated in as little as 16 h from the start of imbibition, without any influence on the soy protein quality or sensory acceptability, while longer imbibition caused the imbibed soybean to activate its phytophysiological metabolism for germination. DNA microarray analysis indicated that the genes for carbohydrate metabolism were up-regulated prior to 16 h, and that the expression rates of genes responsible for environmental factors were down-regulated. Thereafter, the expression rates of the genes associated with lipid metabolism and secondary metabolite production were changed. This information should contribute to a better understanding of how to develop a new soy protein item in pre-germination before active physiological processes begin.

Influence of a short-term iron-deficient diet on hepatic gene expression profiles in rats.

Iron is an essential mineral for the body, and iron deficiency generally leads to anemia. However, because non-anemic iron deficiency can exist, we performed a comprehensive transcriptome analysis of the liver to define the effects of this condition on the body. Four-week-old male rats were fed a low-iron diet (approximately 3 ppm iron) for 3 days and compared with those fed a normal diet (48 ppm iron) by pair feeding as a control. The rats in the iron-deficient diet group developed a non-anemic iron-deficient state. DNA microarray analysis revealed that during this short time, this state conferred a variety of effects on nutrient metabolism in the liver. In comparison with long-term (17 days) iron-deficiency data from a previous study, some of the changed genes were found to be common to both short- and long-term iron deficiency models, some were specific to the short-term iron deficiency model, and the others were oppositely regulated between the two feeding terms. Taken together, these data suggest that although the blood hemoglobin level itself remains unchanged during non-anemic iron deficiency, a variety of metabolic processes involved in the maintenance of the energy balance are altered.

Peanut-skin polyphenols, procyanidin A1 and epicatechin-(4 ß â†’ 6)-epicatechin-(2 ß â†’ O → 7, 4 ß â†’ 8)-catechin, exert cholesterol micelle-degrading activity in vitro.

We identified epicatechin-(4 ß â†’ 6)-epicatechin-(2 ß â†’ O → 7, 4 ß â†’ 8)-catechin (EEC) in the skin of the peanut (Arachis hypogaea L.). EEC (a trimer) showed more potent cholesterol micelle-degrading activity than procyanidin A1 (a dimer) did in vitro. The hypercholesterolemia suppressing effect of a peanut skin polyphenol on rats fed high-cholesterol diet in our preceding experiments might thus have been due primarily to a micelle degrading effect in the intestine.

Novel angiotensin I-converting enzyme inhibitory peptides found in a thermolysin-treated elastin with antihypertensive activity.

Angiotensin I-converting enzyme (ACE) inhibitory activity was generated from elastin and collagen by hydrolyzing with thermolysin. The IC50 value of 531.6 µg/mL for ACE inhibition by the elastin hydrolysate was five times less than 2885.1 µg/mL by the collagen hydrolysate. We confirmed the antihypertensive activity of the elastin hydrolysate in vivo by feeding spontaneously hypertensive rats (male) on a diet containing 1% of the elastin hydrolysate for 9 weeks. About 4 week later, the systolic blood pressure of the rats in the elastin hydrolysate group had become significantly lower than that of the control group. We identified novel ACE inhibitory peptides, VGHyp, VVPG and VYPGG, in the elastin hydrolysate by using a protein sequencer and quadrupole linear ion trap (QIT)-LC/MS/MS. VYPGG had the highest IC50 value of 244 µM against ACE and may have potential use as a functional food.

Serum cholesterol reduction by feeding a high-cholesterol diet containing a lower-molecular-weight polyphenol fraction from peanut skin.

Feeding a high-cholesterol diet with a water-soluble peanut skin polyphenol fraction to rats reduced their plasma cholesterol level, with an increase in fecal cholesterol excretion. The hypocholesterolemic effect was greater with the lower-molecular-weight rather than higher-molecular-weight polyphenol fraction. This effect was possibly due to some oligomeric polyphenols which reduced the solubility of dietary cholesterol in intestinal bile acid-emulsified micelles.

Ingested maple syrup evokes a possible liver-protecting effect-physiologic and genomic investigations with rats.

Rats fed a 20%-maple syrup diet (maple syrup group) for 11 d showed significantly lower values of the hepatic function markers than those fed a 20%-sugar mix syrup diet (control). The reason was suggested by a DNA microarray analysis which revealed that the expression of genes for the enzymes of ammonia formation were down-regulated in the liver of the maple syrup group.

Effects of peanut-skin procyanidin A1 on degranulation of RBL-2H3 cells.

Peanut skin contains large amounts of polyphenols having antiallergic effects. We found that a peanut-skin extract (PSE) inhibits the degranulation induced by antigen stimulation of rat basophilic leukemia (RBL-2H3) cells. A low-molecular-weight fraction from PSE, PSEL, also had inhibitory activity against allergic degranulation. A main polyphenol in PSEL was purified by gel chromatography and fractionated by YMC-gel ODS-AQ 120S50 column. Electrospray ionization mass spectrometry (ESI-MS) analysis of the purified polyphenol gave m/z 599 [M+Na]⁺. Based on the results of ¹H-NMR, ¹³C-NMR spectra, and optical rotation analysis, the polyphenol was identified as procyanidin A1. It inhibited the degranulation caused by antigen stimulation at the IC50 of 20.3 µM. Phorbol-12-myristate-13-acetate (PMA) and 2,5,-di(tert-butyl)-1,4-hydroquinone (DTBHQ)-induced processes of degranulation were also inhibited by procyanidin A1. These results indicate that peanut-skin procyanidin A1 inhibits degranulation downstream of protein kinase C activation or Ca²âº influx from an internal store in RBL-2H3 cells.

Hepatic oxidoreduction-related genes are upregulated by administration of hydrogen-saturated drinking water.

The effects of the administration of molecular hydrogen-saturated drinking water (hydrogen water) on hepatic gene expression were investigated in rats. Using DNA microarrays, 548 upregulated and 695 downregulated genes were detected in the liver after 4 weeks of administration of hydrogen water. Gene Ontology analysis revealed that genes for oxidoreduction-related proteins, including hydroxymethylglutaryl CoA reductase, were significantly enriched in the upregulated genes.

Dietary iron-deficient anemia induces a variety of metabolic changes and even apoptosis in rat liver: a DNA microarray study.

Anemia can be induced by dietary iron deficiency, as well as by hemorrhagia. It may also be associated with changes in lipid metabolism. However, no global analysis detailing the consequences of iron deficiency in the liver has yet been conducted. Since the liver is a metabolically important organ and also a major iron-storing organ, we performed a comprehensive transcriptome analysis to determine the effects of iron deficiency on hepatic gene expression. Four-week-old rats were fed an iron-deficient diet, approximately 3 ppm iron, ad libitum for 16 days. These rats were compared with similar rats pair-fed a control diet with a normal iron level, 48 ppm iron. The 16-day iron-deficient diet apparently induced anemia. On day 17, the rats were killed under anesthesia, and their livers were dissected for DNA microarray analysis. We identified 600 upregulated and 500 downregulated probe sets that characterized the iron-deficient diet group. In the upregulated probe sets, genes involved in cholesterol, amino acid, and glucose metabolism were significantly enriched, while genes related to lipid metabolism were significantly enriched in the downregulated probe sets. We also found that genes for caspases 3 and 12, which mediate endoplasmic reticulum (ER)-specific apoptosis, were upregulated in the iron-deficient group. Combined, these results suggest that iron deficiency exerts various influences, not only on nutrient metabolism but also on apoptosis, as a consequence of ER stress in the liver.

Hypocholesterolemic effect of peanut skin and its fractions: a case record of rats fed on a high-cholesterol diet.

Peanut skin (PS) is characterized by almost exclusively consisting of polyphenols and fiber. We fractionated PS into a water-soluble fraction (WSF) and water-insoluble fraction (WIF), and further fractionated WSF into a soluble dietary fiber fraction (DF) and dietary fiber-free, water-soluble fraction (DFF-WSF). Male Sprague-Dawley rats were fed on high-cholesterol diets supplemented with PS and its fractions. PS, WSF, and DFF-WSF decreased the serum lipid and cholesterol levels and increased those in feces. This effect was probably due to the polyphenols that inhibited intestinal cholesterol absorption.

Blood substrates and hormonal responses to increased egg white protein intake prior to a 12,000 m run in heat.

This study was undertaken to investigate the effects of isoenergetic and increased amounts of egg white protein one hour before a run on the changes in the post-exercise blood biochemistry and the rating of the perceived exertion (RPE). Twenty-four male distance runners were divided into four groups. Venous blood samples were collected at three time points: just before the experiment (Pre), just after a 12,000 m run (Post 0 h) and one hour after the run (Post 1 h). After the first blood sampling, each participant consumed one of the four isoenergetic supplements (86 kcal); 0 g, 5 g, 10 g, or 20 g of egg white protein. The blood glucose, free amino acid, and branched chain amino acid (BCAA) levels in the 0 g, 5 g, and 10 g protein groups were higher at Post 0 h than at Pre. The pre-exercise intake of the 20 g protein group showed the smallest changes in the blood biochemicals. The RPE scores were significantly higher at Post 0 h, and did not vary among the four protein groups. Accordingly, the pre-exercise carbohydrate intakes significantly altered the post-exercise blood biochemisty findings, but the pre-exercise protein intake did not. Furthermore, the changes in the RPE scores in our present study were not explained by changes in the serum free tryptophan or the BCAA levels, and an increased dietary intake of egg white protein might not prevent post-exercise increases in the RPE scores.

Increase of serum cholesterol levels by heat-moisture-treated high-amylose cornstarch in rats fed a high-cholesterol diet.

The effects of four cornstarches containing various contents of resistant starch on serum and liver cholesterol levels in rats fed a high-cholesterol diet were investigated. Male Sprague Dawley rats (aged 4 weeks) were divided into four groups (n = 7) and fed high-cholesterol diets containing 15% of cornstarch (CS), heat-moisture-treated CS (HCS), high-amylose CS (HA), or heat-moisture-treated HA (HHA) for 21 days. The results showed that the serum and hepatic level of total cholesterol, LDL-cholesterol, and triglyceride in rats of the HHA group and their arteriosclerosis index were significantly higher, suggesting that HHA increases the risk of arteriosclerosis under a high-cholesterol dietary condition. No significant between-group differences were noted in the levels of plasma mevalonic acid and hepatic HMG-CoA reductase mRNA, whereas fecal cholesterol excretion was significantly higher in the HHA group, indicating that the elevation of the serum and liver cholesterol levels was not due to the promotion of liver cholesterol synthesis and cholesterol absorption in the intestine.

Serum cholesterol-decreasing effect of heat-moisture-treated high-amylose cornstarch in cholesterol-loaded rats.

Rats were fed on a diet containing cholesterol (Chol) at a level corresponding to the standard Chol intake in humans, and the influence of heat-moisture-treated high-amylose cornstarch (HHA) on their serum Chol level was investigated. HHA decreased the serum level of Chol in rats fed on the diet containing 0.1% Chol, which corresponds to a Chol intake in humans of 800 mg/d, although the liver levels of Chol increased in these rats. HHA did not influence the fecal excretion of Chol/bile acids. It is possible that the decrease in serum Chol level in the rats fed on the high-Chol diet can be attributed to the promotion of Chol uptake in the liver.

Functional food science and food for specified health use policy in Japan: state of the art.

PURPOSE OF REVIEW: The science and policy of functional foods are a matter of global concern and this review provides up-to-date information about the Japanese 'food for specified health use' policy based on functional food science. RECENT FINDINGS: A great many studies on nonnutritive but physiologically functional food components have provided more precise evidence regarding the structure-function relationships that underlie the approval of food for specified health use products. SUMMARY: Functional foods, defined as those that have the potential to reduce the risk of lifestyle-related diseases and associated abnormal modalities, have garnered global interest since the 1980s when the systematic research had humble beginnings as a national project in Japan. In 1991, the project led to the launch of the national food for specified health use policy; 703 food for specified health use products with 11 categories of health claims have been approved up to the present (31 August 2007). The development of this policy has been supported basically by nutritional epidemiology, food chemistry and biochemistry, physiology and clinical medicine, and even the genomics on food and nutrition. This review also highlights the current academia-industry collaboration in Japan.

Molecular cloning and characterization of an alpha-amylase from Pichia burtonii 15-1.

An alpha-amylase secreted by Pichia burtonii 15-1 isolated from a traditional starter murcha of Nepal, named Pichia burtonii alpha-amylase (PBA), was studied. The gene was cloned and its nucleotide sequence was determined. PBA was deduced to consist of 494 amino acid residues. It shared certain degrees of amino acid sequence identity with other homologous proteins: 60% with Schwanniomyces occidentalis alpha-amylase, 58% with Saccharomycopsis sp. alpha-amylase, and 47% with Taka-amylase A from Aspergillus oryzae. A three-dimensional structural model of PBA generated using the known three-dimensional structure of Taka-amylase A as a template suggested high structural similarity between them. Kinetic analysis revealed that the K(m) values of PBA were lower than those of Taka-amylase A for the oligosaccharides. Although the k(cat) values of PBA were lower than those of Taka-amylase A for the oligosaccharide substrates, the k(cat)/K(m) values of PBA were higher.