Suppressive Effects of Turmeric Extract on Muscle Atrophy in Dexamethasone-Treated Mice and Myotubes.

Sarcopenia is the decline in skeletal muscle mass, strength, and functions, which decreases the quality of life in elderly people. This study investigated the suppressive effect of turmeric (Curcuma longa) extract (TE) on muscle atrophy in dexamethasone (DEX)-treated mice and C2C12 myotubes. DEX treatment significantly decreased the muscle weight and significantly increased Fbxo32 and Murf1 expression in mice, and these changes were suppressed by the supplementation of an AIN-93 based diet with 2% TE. A similar pattern was observed in FBXO32 and MuRF1 protein expression. In C2C12 myotubes, DEX treatment significantly increased FBXO32 and MuRF1 gene and protein expression, and these increases were significantly suppressed by TE supplementation at a concentration of 200 µg/mL. Furthermore, one of the five TE fractions, which were separated by high-performance liquid chromatography had a similar effect with TE supplementation. The present study proposes the suppressive effect of turmeric on sarcopenia.

Laurel Attenuates Dexamethasone-Induced Skeletal Muscle Atrophy In Vitro and in a Rat Model.

Prevention of muscle atrophy contributes to improved quality of life and life expectancy. In this study, we investigated the effects of laurel, selected from 34 spices and herbs, on dexamethasone (DEX)-induced skeletal muscle atrophy and deciphered the underlying mechanisms. Co-treatment of C2C12 myotubes with laurel for 12 h inhibited the DEX-induced expression of intracellular ubiquitin ligases-muscle atrophy F-box (atrogin-1/MAFbx) and muscle RING finger 1 (MuRF1)-and reduction in myotube diameter. Male Wistar rats were supplemented with 2% laurel for 17 days, with DEX-induced skeletal muscle atrophy occurring in the last 3 days. Laurel supplementation inhibited the mRNA expression of MuRF1, regulated DNA damage and development 1 (Redd1), and forkhead box class O 1 (Foxo1) in the muscles of rats. Mechanistically, we evaluated the effects of laurel on the cellular proteolysis machinery-namely, the ubiquitin/proteasome system and autophagy-and the mTOR signaling pathway, which regulates protein synthesis. These data indicated that the amelioration of DEX-induced skeletal muscle atrophy induced by laurel, is mainly mediated by the transcriptional inhibition of downstream factors of the ubiquitin-proteasome system. Thus, laurel may be a potential food ingredient that prevents muscle atrophy.

iTRAQ-Based Quantitative Proteomics Reveals the Energy Metabolism Alterations Induced by Chlorogenic Acid in HepG2 Cells.

Epidemiological studies have suggested that coffee consumption is associated with a decrease in the risk of developing obesity and diabetes; however, the detailed mechanisms underlying these effects of coffee consumption remain poorly understood. In this study, we examined the effects of chlorogenic acid on energy metabolism in vitro. Hepatocellular carcinoma G2 (HepG2) cells were cultured in a medium containing chlorogenic acid. Chlorogenic acid increased the activity of mitochondrial enzymes, including citrate synthase, isocitrate dehydrogenase, and malate dehydrogenase (MDH), which are involved in the tricarboxylic acid (TCA) cycle. Proteome analysis using the isobaric tags for the relative and absolute quantitation (iTRAQ) method revealed the upregulation of proteins involved in the glycolytic system, electron transport system, and ATP synthesis in mitochondria. Therefore, we propose a notable mechanism whereby chlorogenic acid enhances energy metabolism, including the TCA cycle, glycolytic system, electron transport, and ATP synthesis. This mechanism provides important insights into understanding the beneficial effects of coffee consumption.

Ameliorating Effects of Coriander on Gastrocnemius Muscles Undergoing Precachexia in a Rat Model of Rheumatoid Arthritis: A Proteomics Analysis.

Coriander is a commonly used vegetable, spice, and folk medicine, possessing both nutritional and medicinal properties. Up to two-thirds of patients with rheumatoid arthritis (RA) exhibit loss of body mass, predominately skeletal muscle mass, a process called rheumatoid cachexia, and this has major effects of the quality of life of patients. Owing to a lack of effective treatments, the initial stage of cachexia has been proposed as an important period for prevention and decreasing pathogenesis. In the current study, we found that cachexia-like molecular disorders and muscle weight loss were in progress in gastrocnemius muscle after only 5 days of RA induction in rats, although rheumatoid cachexia symptoms have been reported occurring approximately 45 days after RA induction. Oral administration of coriander slightly restored muscle loss. Moreover, iTRAQ-based quantitative proteomics revealed that coriander treatment could partially restore the molecular derangements induced by RA, including impaired carbon metabolism, deteriorated mitochondrial function (tricarboxylic acid cycle and oxidative phosphorylation), and myofiber-type alterations. Therefore, coriander could be a promising functional food and/or complementary therapy for patients with RA against cachexia.

Effects of Eggshell Membrane on Keratinocyte Differentiation and Skin Aging In Vitro and In Vivo.

Skin aging is one of the hallmarks of the aging process that causes physiological and morphological changes. Recently, several nutritional studies were conducted to delay or suppress the aging process. This study investigated whether nutritional supplementation of the eggshell membrane (ESM) has a beneficial effect on maintaining skin health and improving the skin aging process in vitro using neonatal normal human epidermal keratinocytes (NHEK-Neo) and in vivo using interleukin-10 knockout (IL-10 KO) mice. In NHEK-Neo cells, 1 mg/mL of enzymatically hydrolyzed ESM (eESM) upregulated the expression of keratinocyte differentiation markers, including keratin 1, filaggrin and involucrin, and changed the keratinocyte morphology. In IL-10 KO mice, oral supplementation of 8% powdered-ESM (pESM) upregulated the expression of growth factors, including transforming growth factor ß1, platelet-derived growth factor-ß and connective tissue growth factor, and suppressed skin thinning. Furthermore, voltage-gated calcium channel, transient receptor potential cation channel subfamily V members were upregulated by eESM treatment in NHEK-Neo cells and pESM supplementation in IL-10 KO mice. Collectively, these data suggest that ESM has an important role in improving skin health and aging, possibly via upregulating calcium signaling.

A Genome-Wide Association Study Identifies the Association between the 12q24 Locus and Black Tea Consumption in Japanese Populations.

Several genome-wide association studies (GWASs) have reported the association between genetic variants and the habitual consumption of foods and drinks; however, no association data are available regarding the consumption of black tea. The present study aimed to identify genetic variants associated with black tea consumption in 12,258 Japanese participants. Data on black tea consumption were collected by a self-administered questionnaire, and genotype data were obtained from a single nucleotide polymorphism array. In the discovery GWAS, two loci met suggestive significance (p < 1.0 × 10-6). Three genetic variants (rs2074356, rs144504271, and rs12231737) at 12q24 locus were also significantly associated with black tea consumption in the replication stage (p < 0.05) and during the meta-analysis (p < 5.0 × 10-8). The association of rs2074356 with black tea consumption was slightly attenuated by the additional adjustment for alcohol drinking frequency. In conclusion, genetic variants at the 12q24 locus were associated with black tea consumption in Japanese populations, and the association is at least partly mediated by alcohol drinking frequency.

GWAS of habitual coffee consumption reveals a sex difference in the genetic effect of the 12q24 locus in the Japanese population.

BACKGROUND: Studies on genetic effects of coffee consumption are scarce for Asian populations. We conducted a genome-wide association study (GWAS) of habitual coffee consumption in Japan using a self-reporting online survey. RESULTS: Candidate genetic loci associated with habitual coffee consumption were searched within a discovery cohort (N = 6,264) and confirmed in a replication cohort (N = 5,975). Two loci achieved genome-wide significance (P < 5 × 10- 8) in a meta-analysis of the discovery and replication cohorts: an Asian population-specific 12q24 (rs79105258; P = 9.5 × 10- 15), which harbors CUX2, and 7p21 (rs10252701; P = 1.0 × 10- 14), in the upstream region of the aryl hydrocarbon receptor (AHR) gene, involved in caffeine metabolism. Subgroup analysis revealed a stronger genetic effect of the 12q24 locus in males (P for interaction = 8.2 × 10- 5). Further, rs79105258 at the 12q24 locus exerted pleiotropic effects on body mass index (P = 3.5 × 10- 4) and serum triglyceride levels (P = 8.7 × 10- 3). CONCLUSIONS: Our results consolidate the association of habitual coffee consumption with the 12q24 and 7p21 loci. The different effects of the 12q24 locus between males and females are a novel finding that improves our understanding of genetic influences on habitual coffee consumption.

Zeolite-Containing Mixture Supplementation Ameliorated Dextran Sodium Sulfate-Induced Colitis in Mice by Suppressing the Inflammatory Bowel Disease Pathway and Improving Apoptosis in Colon Mucosa.

Inflammatory bowel disease (IBD) is induced by multiple environmental factors, and there is still no known treatment capable of curing the disease completely. We propose a zeolite-containing mixture (Hydryeast®, HY)-a multi-component nutraceutical of which the main ingredients are Azumaceramics (mixture of zeolite and oyster shell burned under high temperature), citric acid, red rice yeast (monascus) and calcium stearate-as a nutraceutical intervention in IBD to ameliorate dextran sodium sulfate (DSS)-induced colitis. We show the mechanism through integrated omics using transcriptomics and proteomics. C57BL6 mice were given an AIN-93G basal diet or a 0.8% HY containing diet and sterilized tap water for 11 days. Colitis was then induced by 1.5% (w/v) DSS-containing water for 9 days. HY fed mice showed significantly improved disease activity index and colon length compared to DSS mice. Colonic mucosa microarray analysis plus RT-PCR results indicate HY supplementation may ameliorate inflammation by inhibiting the intestinal inflammatory pathway and suppress apoptosis by curbing the expression of genes like tumor protein 53 and epidermal growth factor receptor and by upregulating epithelial protection-related proteins such as epithelial cell adhesion molecule and tenascin C, thus maintaining mucosal immune homeostasis and epithelial integrity, mirroring the proteome analysis results. HY appears to have a suppressive effect on colitis.

Acerola (Malpighia emarginata DC.) Juice Intake Suppresses UVB-Induced Skin Pigmentation in SMP30/GNL Knockout Hairless Mice.

BACKGROUND/AIMS: Acerola (Malpighia emarginata DC.) is a fruit that is known to contain high amounts of ascorbic acid (AA) and various phytochemicals. We have previously reported that AA deficiency leads to ultraviolet B (UVB)-induced skin pigmentation in senescence marker protein 30 (SMP30)/gluconolactonase (GNL) knockout (KO) hairless mice. The present study was undertaken to investigate the effects of acerola juice (AJ) intake on the skin of UVB-irradiated SMP30/GNL KO mice. RESEARCH DESIGN/PRINCIPAL FINDINGS: Five-week old hairless mice were given drinking water containing physiologically sufficient AA (1.5 g/L) [AA (+)], no AA [AA (-)] or 1.67% acerola juice [AJ]. All mice were exposed to UVB irradiation for 6 weeks. UVB irradiation was performed three times per week. The dorsal skin color and stratum corneum water content were measured every weekly, and finally, the AA contents of the skin was determined. The skin AA and stratum corneum water content was similar between the AA (+) and AJ groups. The L* value of the AA (+) group was significantly decreased by UVB irradiation, whereas AJ intake suppressed the decrease in the L* value throughout the experiment. Moreover, in the AJ group, there was a significant decrease in the expression level of dopachrome tautomerase, an enzyme that is involved in melanin biosynthesis. CONCLUSION: These results indicate that AJ intake is effective in suppressing UVB-induced skin pigmentation by inhibiting melanogenesis-related genes.

Supplemental arginine above the requirement during suckling causes obesity and insulin resistance in rats.

Nutrition in early life is important in determining susceptibility to adult obesity, and arginine may promote growth acceleration in infants. We hypothesized that maternal arginine supplementation may promote growth in their pups and contribute to obesity and alteration of the metabolic system in later life. Dams and pups of Wistar rats were given a normal diet (15% protein) as a control (CN) or a normal diet with 2% arginine (ARG). Altered profiles of free amino acids in breast milk were observed in that the concentrations of threonine and glycine were lower in the ARG dams compared with the CN dams. The offspring of the CN and ARG dams were further subdivided into normal-diet (CN-CN and ARG-CN) groups and a high fat-diet groups (CN-HF and ARG-HF). In response to the high fat-diet feeding, the visceral fat deposits were significantly increased in the ARG-HF group (although not compared with the CN-HF group); no difference was observed between the CN-CN and ARG-CN groups. The blood glucose and insulin levels after glucose loading were significantly higher in the ARG-HF group compared with the CN-HF group. The results suggest that the offspring of dams supplemented with arginine during lactation acquired increased susceptibility to a high-fat diet, resulting in visceral obesity and insulin resistance. The lower supply of threonine and glycine to pups may be one of the contributing causes to the programming of lifelong obesity risk in offspring. Our findings also indicated that maternal arginine supplementation during suckling causes obesity and insulin resistance in rats.

Beneficial effects of soluble dietary Jerusalem artichoke (Helianthus tuberosus) in the prevention of the onset of type 2 diabetes and non-alcoholic fatty liver disease in high-fructose diet-fed rats.

Jerusalem artichoke (JA) has the potential to attenuate lipid disturbances and insulin resistance (IR), but the underlying mechanisms are not well understood. In the present study, we elucidated the physiological responses and mechanisms of JA intervention with a comprehensive transcriptome analysis. Wistar rats were fed a control diet, a 60 % fructose-enriched diet (FRU), or a FRU with 10 % JA (n 6-7) for 4 weeks. An oral glucose tolerance test was carried out on day 21. Liver samples were collected for biochemical and global gene expression analyses (GeneChip® Rat Genome 230 2.0 Array, Affymetrix). Fructose feeding resulted in IR and hepatic TAG accumulation; dietary JA supplementation significantly improved these changes. Transcriptomic profiling revealed that the expression of malic enzyme 1 (Me1), associated with fatty acid synthesis; decorin (Dcn), related to fibrosis; and cytochrome P450, family 1, subfamily a, polypeptide 2 (Cyp1a2) and nicotinamide phosphoribosyltransferase (Nampt), associated with inflammation, was differentially altered by the FRU, whereas dietary JA supplementation significantly improved the expression of these genes. We established for the first time the molecular mechanisms driving the beneficial effects of JA in the prevention of type 2 diabetes and non-alcoholic fatty liver disease. We propose that 10 % JA supplementation may be beneficial for the prevention of the onset of these diseases.

Luteolin and quercetin affect the cholesterol absorption mediated by epithelial cholesterol transporter niemann-pick c1-like 1 in caco-2 cells and rats.

Niemann-Pick C1-Like 1 (NPC1L1) mediates cholesterol absorption, and ezetimibe is a potent NPC1L1 inhibitor applicable for medication of hypercholesterolemia. Epidemiological studies demonstrated that consumption of polyphenols correlates with a decreased risk for atherosclerosis due to their antioxidant effect. This activity can hardly be attributable to the antioxidant activity only, and we hypothesized that polyphenols inhibit intestinal transport of cholesterol. We elucidated the kinetic parameters of intestinal cholesterol absorption, screened several polyphenols for their ability to specifically inhibit intestinal cholesterol absorption, and determined the inhibitory effects of selected flavonoids in vitro and in vivo. The concentration-dependent uptake of cholesterol by Caco-2 cells obeyed a monophasic saturation process. This indicates the involvement of an active-passive transport, i.e., NPC1L1. Parameters of cholesterol uptake by Caco-2 cells were as follows: Jmax, Kt, and Kd were 6.89±2.96 19.03±11.58 µM, and 0.11±0.02 pmol/min/mg protein, respectively. Luteolin and quercetin inhibited cholesterol absorption by Caco-2 cells and human embryonic kidney 293T cells expressing NPC1L1. When preincubated Caco-2 cells with luteolin and quercetin before the assay, cholesterol uptake significantly decreased. The inhibitory effects of these flavonoids were maintained for up to 120 min. The level of inhibition and irreversible effects were similar to that of ezetimibe. Serum cholesterol levels significantly decreased more in rats fed both cholesterol and luteolin (or quercetin), than in those observed in the cholesterol feeding group. As quercetin induced a significant decrease in the levels of NPC1L1 mRNA in Caco-2 cells, the in vivo inhibitory effect may be due to the expression of NPC1L1. These results suggest that luteolin and quercetin reduce high blood cholesterol levels by specifically inhibiting intestinal cholesterol absorption mediated by NPC1L1.

An integrated multi-omics study revealed metabolic alterations underlying the effects of coffee consumption.

Many epidemiological studies have indicated that coffee consumption may reduce the risks of developing obesity and diabetes, but the underlying mechanisms of these effects are poorly understood. Our previous study revealed the changes on gene expression profiles in the livers of C57BL/6J mice fed a high-fat diet containing three types of coffee (caffeinated, decaffeinated and green unroasted coffee), using DNA microarrays. The results revealed remarkable alterations in lipid metabolism-related molecules which may be involved in the anti-obesity effects of coffee. We conducted the present study to further elucidate the metabolic alterations underlying the effects of coffee consumption through comprehensive proteomic and metabolomic analyses. Proteomics revealed an up-regulation of isocitrate dehydrogenase (a key enzyme in the TCA cycle) and its related proteins, suggesting increased energy generation. The metabolomics showed an up-regulation of metabolites involved in the urea cycle, with which the transcriptome data were highly consistent, indicating accelerated energy expenditure. The TCA cycle and the urea cycle are likely be accelerated in a concerted manner, since they are directly connected by mutually providing each other's intermediates. The up-regulation of these pathways might result in a metabolic shift causing increased ATP turnover, which is related to the alterations of lipid metabolism. This mechanism may play an important part in the suppressive effects of coffee consumption on obesity, inflammation, and hepatosteatosis. This study newly revealed global metabolic alterations induced by coffee intake, providing significant insights into the association between coffee intake and the prevention of type 2 diabetes, utilizing the benefits of multi-omics analyses.

Adverse effects of excessive leucine intake depend on dietary protein intake: a transcriptomic analysis to identify useful biomarkers.

The present study was conducted to identify reliable gene biomarkers for the adverse effects of excessive leucine (Leu) in Sprague-Dawley rats by DNA microarray. It has long been known that the adverse effects of excessive amino acid intake depend on dietary protein levels. Male rats were divided into 12 groups (n=6) and fed for 1 wk a diet containing low (6%), moderate (12%) or high (40%) protein. Different levels of Leu (0, 2, 4, and 8%) were added to the diets. Consumption of diets containing more than 4% Leu in 6% protein resulted in growth retardation and reduced liver weight, whereas the administration of the same dose of Leu with 12% or 40% protein did not affect them. By a process of systematic data extraction, 6 candidate gene markers were identified. The liver gene expression data obtained from another experiment with 0, 2, 3, 4, and 8% Leu in a low-protein diet was used to examine the validity of these biomarker candidates with receiver operating characteristic (ROC) curve analysis. All of AUC values of the biomarker candidates were more than 0.700, suggesting the effectiveness of the marker candidates as the indices of Leu excess. The cut-off value for the ROC curve of the gene-marker panel, which was obtained by multiple regression analysis of gene markers, indicated that Leu levels higher than 3% have adverse effects. In conclusion, the gene-marker panel suggested that for male rats dietary Leu supplementation of 2% is the NOAEL dose in low-protein (6%) diets.

DNA microarray analysis identified molecular pathways mediating the effects of supplementation of branched-chain amino acids on CCl4-induced cirrhosis in rats.

SCOPE: This study addresses the effects of branched-chain amino acids (BCAA) on global gene expression in liver and skeletal muscle and the molecular mechanisms underlying the improvement in liver cirrhosis using DNA microarray analysis combined with RNase protection assay. METHODS AND RESULTS: Male Wistar rats administered carbon tetrachloride (CCl(4) ) repeatedly for 19 weeks as a decompensated cirrhosis model were thereafter given BCAA-enriched diet (AL) or normal diet (LC) for 5 weeks. The control-diet rats without CCl(4) administration were used as a normal control group. Gene expression in AL was reversed by twofold greater than in LC in the microarray were selected to elucidate the improvements in nutritional and metabolic disorders. Downregulation of fatty acid translocase (FAT)/Cd36, glutamine synthetase, and pyruvate dehydrogenase kinase isoenzyme 4 is believed to promote lower uptake of fatty acids, lower ammonia incorporation, and higher uptake of glucose, and thus to provide an energy source without using BCAA. Ultimately, the catabolism of BCAA and skeletal muscle protein would be slowed, maintaining BCAA concentrations in blood. CONCLUSION: We established, for the first time, the regulatory gene pathways of processes involved in hepatic fibrosis and energy metabolism (hypoalbuminemia, hyperammonemia, and carbohydrate catabolism, and their relationships) under BCAA supplementation.

Omics and integrated omics for the promotion of food and nutrition science.

Transcriptomics, proteomics, and metabolomics are three major platforms of comprehensive omics analysis in the science of food and complementary medicine. Other omics disciplines, including those of epigenetics and microRNA, are matters of increasing concern. The increased use of the omics approach in food science owes much to the recent advancement of technology and bioinformatic methodologies. Moreover, many researchers now put the combination of multiple omics analysis (integrated omics) into practice to exhaustively understand the functionality of food components. However, data analysis of integrated omics requires huge amount of work and high skill of data handling. A database of nutritional omics data was constructed by the authors, which should help food scientists to analyze their own omics data more effectively. In addition, a novel tool for the easy visualization of omics data was developed by the authors' group. The tool enables one to overview the changes of multiple omics in the KEGG pathway. Research in traditional and complementary medicine will be further facilitated by promoting the integrated omics research of food functionality. Such integrated research will only be possible with the effective collaboration of scientists with different backgrounds.

A novel PCR method for quantification of buckwheat by using a unique internal standard material.

A novel quantitative and specific method for detection of buckwheat, a known food allergen, in diverse food materials was developed by using a unique internal standard to compensate for the variability in DNA extraction and amplification efficiencies. The method was based on a real-time PCR targeting the internal transcribed spacer region of Fagopyrum spp. and was designed to detect both cultivated and wild buckwheat, because wild buckwheat might be potentially allergenic. As the internal standard material, ground seeds of statice (Limonium sinuatum) were added to food samples prior to DNA extraction, and the amount of statice DNA measured by real-time PCR was used to standardize the buckwheat content. Statice, an ornamental plant, was chosen as the internal standard material because it was readily available and was inferred to be least likely to be commingled in foods. The specificity of the PCR system was tested against commonly used food materials of plant origin. Quantitative results expressed in buckwheat protein concentrations (mean +/- standard deviation) for various food samples prepared to contain 10 ppm (wt/wt) of buckwheat flour (corresponding to 1.2-microg/g [ppm] buckwheat protein) ranged from 0.7 +/- 0.2 (rice) to 0.9 +/- 0.4 (wheat) and for 100-ppm (wt/wt) samples (12-microg/g [ppm] buckwheat protein) from 7.7 +/- 1.0 (pepper) to 9.8 +/- 0.5 (wheat) microg/g (ppm). The method's accuracy, sensitivity, and specificity were considered sufficient for detection of buckwheat contamination at the level required for compliance with the Japanese Food Allergen Labeling Regulation.

PCR method for detecting trace amounts of buckwheat (Fagopyrum spp.) in food.

Buckwheat often causes severe allergic reactions, even when its ingestion level is extremely low. Therefore, buckwheat is listed in several countries as a common food allergen. In addition to common buckwheat and Tartarian buckwheat that are cultivated and consumed widely, wild buckwheat may be potentially allergenic. Food containing undeclared buckwheat poses a risk to patients with the buckwheat allergy. We describe in this report a PCR method to detect buckwheat DNA by using primers corresponding to the internal transcribed spacer region and the 5.8S rRNA gene. The method is buckwheat-specific and compatible with both cultivated and wild buckwheat of the Fagopyrum spp. Its sensitivity was sufficient to detect 1 ppm (w/w) of buckwheat DNA spiked in wheat DNA. This method should benefit food manufacturers, clinical doctors, and allergic patients by providing information on the presence of buckwheat contamination in food.