Wallace Yokoyama

Effect of Barley β-Glucan in Durum Wheat Pasta on Human Glycemic Response

ABSTRACT High-fiber, high-carbohydrate diets, including foods with low glycemic index, have been associated with prevention and treatment of diseases such as coronary heart disease and diabetes. β-glucan, a soluble, viscous polymer found in oat and barley endosperm cell wall, was incorporated into pasta test meals. Five fasted adult subjects were fed test meals of a barley and durum wheat blend pasta containing 100 g of available carbohydrate, 30 g of total dietary fiber (TDF) and 12 g of β-glucan, or an all durum wheat pasta containing the same amount of available carbohydrate, 5 g of TDF, and negligible β-glucan. The β-glucan and durum wheat pasta resulted in a lower glycemic response as measured by average total area and maximum increment of the blood glucose curves. Lower insulin response to the β-glucan and durum wheat pasta was also indicated by lower average area and increment characteristics of the insulin curves. Barley β-glucans may be an economical and palatable ingredient for processed food pr...

Butyric Acid from the Diet: Actions at the Level of Gene Expression

A number of components present in the diet, although nutritionally nonessential, have been discovered to have beneficial effects toward both general health and disease prevention/protection. One such nutrient, butyric acid, can be derived in large quantities from bacterial fementation of dietary fiber in the bowel and is also a component of bovine milk. In gut fermentation, the production of butyric acid defines its delivery point; thus, the synthesis and site of action of butyric acid are in close proximity and have frustrated the investigation of its activities in vivo. Recent research has, however, revealed a number of activities of butyric acid toward isolated cells. In particular, its ability to modify nuclear architecture and induce death by apoptosis in colon cancer cells is arousing great interest. Butyric acid changes the structure of chromatin through its effects on posttranslational modifications, key modifications being acetylation and phosphorylation of the nuclear histones. Butyric acid can also modify the differentiation state of cells, and in the case of cancerous colonic cells overcomes their resistance to normal programmed death. Thus, the activities of this fermentation product of dietary fiber may contribute substantially to the decreased incidence of bowel cancer that has been associated with fiber intake.

Effect of dietary catechin and vitamin E on aortic fatty streak accumulation in hypercholesterolemic hamsters

Male golden Syrian hamsters were fed for 16 weeks on a hypercholesterolemic diet containing, per kg, 150 g of lipids (90 g butterfat, 35 g vitamin E-stripped corn oil and 25 g fish oil), 2 g cholesterol and either 3 IU vitamin E (3 IU E), 3 IU vitamin E and 200 mg catechin hydrate (3 IU E-200 Cat) or 30 IU vitamin E (30 IU E). More fatty streaks, measured by Oil Red O staining, were deposited in aortas of hamsters fed 3 IU E than in those fed either 3 IU E-200 Cat or 30 IU E. Lipid staining increased with plasma low-density lipoprotein cholesterol (LDL-C) in all animals. At the same concentration of LDL-C, animals fed either 3 IU E-200 Cat or 30 IU E developed less fatty streaks than those fed 3 IU E. Plasma LDL-C and total cholesterol were highest in hamsters fed 3 IU E and LDL-C and total cholesterol in animals fed 3 IU-200 Cat were not different from those fed either 3 IU E or 30 IU E. This study showed the importance of circulating plasma LDL-C on atherogenesis and the inhibitory effect on this process of both dietary vitamin E and catechin.

Starch Molecular Mass and Size by Size-Exclusion Chromatography in DMSO-LiBr Coupled with Multiple Angle Laser Light Scattering

ABSTRACT The weight average molar mass (Mw) and root mean square radii of starches from waxy maize (Amioca), waxy rice flour, cassava, Hylon V, Hylon VII, and potato amylose were determined by size-exclusion chromatography (SEC) and multiple-angle laser light scattering (MALLS). Dimethylsulfoxide (DMSO) containing 50 mM LiBr was used to dissolve the starches and also served as the mobile phase. SEC with large particle size polystyrene divinylbenzene packing materials and MALLS instrumentation were evaluated for the ability to separate and determine molar mass (MM) of starch polymers, respectively. The determination of Mw by MALLS is necessary because the Mw of many cereal starches exceeds the available molecular standards by one or two orders of magnitude. The Mw depends on the method of calculation. The Mw (Berry method) of starch from waxy corn was 2.27 × 108 Da, waxy rice 8.9 × 107 Da, cassava 5.7 × 107 Da, Hylon V 2.7 × 107 Da, Hylon VII 4.8 × 106 Da, and potato amylose 1.9 × 105 Da. Recovery dropped ...

Cinnamon intake lowers fasting blood glucose: meta-analysis.

Cinnamon, the dry bark and twig of Cinnamomum spp., is a rich botanical source of polyphenolics that has been used for centuries in Chinese medicine and has been shown to affect blood glucose and insulin signaling. Cinnamons effects on blood glucose have been the subject of many clinical and animal studies; however, the issue of cinnamon intakes effect on fasting blood glucose (FBG) in people with type 2 diabetes and/or prediabetes still remains unclear. A meta-analysis of clinical studies of the effect of cinnamon intake on people with type 2 diabetes and/or prediabetes that included three new clinical trials along with five trials used in previous meta-analyses was done to assess cinnamons effectiveness in lowering FBG. The eight clinical studies were identified using a literature search (Pub Med and Biosis through May 2010) of randomized, placebo-controlled trials reporting data on cinnamon and/or cinnamon extract and FBG. Comprehensive Meta-Analysis (Biostat Inc., Englewood, NJ, USA) was performed on the identified data for both cinnamon and cinnamon extract intake using a random-effects model that determined the standardized mean difference ([i.e., Change 1(control) - Change 2(cinnamon)] divided by the pooled SD of the post scores). Cinnamon intake, either as whole cinnamon or as cinnamon extract, results in a statistically significant lowering in FBG (-0.49±0.2 mmol/L; n=8, P=.025) and intake of cinnamon extract only also lowered FBG (-0.48 mmol/L±0.17; n=5, P=.008). Thus cinnamon extract and/or cinnamon improves FBG in people with type 2 diabetes or prediabetes.

Effect of dietary fats and barley fiber on total cholesterol and lipoprotein cholesterol distribution in plasma of hamsters

Abstract Dietary saturated fatty acids and cholesterol elevate blood lipids, promote hypercholesterolemia and lead to elevation of circulating very low density (VLDL) and low density lipoproteins (LDL). Dietary fiber is suggested to ameliorate hypercholesterolemia. This study was undertaken to determine if dietary fiber would alter the quantity and distribution of cholesterol among plasma lipoproteins in the well-described model of dietary fat-induced hypercholesterolemia, the golden Syrian hamster. Hamsters were fed a basal high fat diet with 2.5% safflower oil and 10% butterfat to which had been added either 2.5% olive oil or 2.5% fish oil. Fiber was provided as cellulose or beta-glucan-enriched barley fiber at 10% of the diet. In hamsters fed 10% butterfat, 2.5% olive oil and cellulose, plasma cholesterol content was 237 mg/100 mL, with 65% of the total plasma cholesterol distributed in high density lipoproteins (HDL) and 35% in LDL plus VLDL. In hamsters fed 10% butterfat and 2.5% fish oil and cellulose, total cholesterol was 297 mg/100 mL, and 32% of the cholesterol was associated with HDL and 68% with LDL plus VLDL. These data indicated a significant redistribution of cholesterol from the HDL to the LDL and VLDL in fish oil fed animals. Substitution of barley fiber for cellulose in diets tended to decrease plasma cholesterol, however, it did not significantly affect the distribution of cholesterol among the lipoprotein classes. Serum triglycerides were higher in plasma of hamsters fed fish oil, and fiber did not alter either total triglycerides or distribution of triglycerides among lipoprotein classes. This study suggested that cholesterol distribution in plasma of hamsters fed cholesterolemic diets is more responsive to dietary fat than fiber and is due to mechanisms additional to hepatic LDL-receptor binding activity.

Hypocholesterolemic Effects of Hydroxypropyl Methylcellulose Are Mediated by Altered Gene Expression in Hepatic Bile and Cholesterol Pathways of Male Hamsters

Hydroxypropyl methylcellulose (HPMC), a semisynthetic, nonfermentable soluble dietary fiber, is not absorbed by the body, but its presence in the intestinal lumen increases fecal fat, sterol, and bile acid excretions and decreases intestinal cholesterol absorption, all of which may indirectly affect hepatic lipid metabolism. We measured the expression of hepatic genes involved in cholesterol, bile acid, and fatty acid metabolism in hamsters fed diets containing 39% of energy as fat and 5% of weight as HPMC or microcrystalline cellulose (control) for 4 wk. HPMC-fed hamsters gained significantly less body weight than the control group but did not differ in food intake. They had significantly lower plasma triglyceride and total-, VLDL-, HDL-, and LDL-cholesterol concentrations and hepatic total lipid, total and free cholesterol and triglyceride concentrations than controls. Compared with controls, HPMC-fed hamsters had greater levels of mRNA for CYP7A1 (cytochrome P450 7A1; 8-fold of control; P < 0.05), CYP51 (lanosterol 14alpha-demethylase; 5.3-fold of control; P < 0.05), and HMG-CoAR (3-hydroxy-3-methylglutaryl CoA reductase; 1.8-fold of control; P < 0.05). The plasma total cholesterol concentrations from both the control and HPMC groups were inversely correlated with expression of hepatic CYP7A1 (r = -0.54; P < 0.05), CYP51 (r = -0.79; P < 0.005), and HMG-CoAR (r = -0.75; P < 0.005) genes. This suggests that HPMC supplementation affected both cholesterol and bile acid synthesis. Our data confirm that altered hepatic expression of lipid metabolism-related genes, possibly due to modulation of fecal bile acid excretion and intestinal cholesterol absorption, contributes to the lipid-lowering effects of HPMC.

Molecular Characterization of Barley β-Glucans by Size-Exclusion Chromatography with Multiple-Angle Laser Light Scattering and Other Detectors

ABSTRACT Molecular characteristics were determined for mixed-linkage (1→3) (1→4)-β-d-glucans (β-glucans) extracted from Azhul, Crystal, Waxbar, and Prowashonupana barleys. β-Glucans in extracts (with or without α-amylase, protease, hemicellulase, or xylanase treatment) were separated from other components by high-performance size-exclusion chromatography and detected with multiple-angle laser light scattering, refractive index, and fluorometry following postrefractive index treatment with Calcofluor. Pretreatment of barley with 70% ethanol (80°C, 4 hr) reduced β-glucanase activity by ~20%. Hot-alcohol treatment also reduced β-glucan extraction at 23 and 65°C by 42 and 14%, respectively. Molecular weights of β-glucans in the first water extract were generally higher than in succeeding water and alkali extracts. Weight average molecular weights ranged from 0.44 × 106 to 2.34 × 106 g/mol after α-amylase treatment to remove interfering starch. Interference due to pentosans was not demonstrated using enzyme tr...

Cellular Uptake of β-Carotene from Protein Stabilized Solid Lipid Nanoparticles Prepared by Homogenization–Evaporation Method

With a homogenization-evaporation method, β-carotene (BC) loaded nanoparticles were prepared with different ratios of food-grade sodium caseinate (SC), whey protein isolate (WPI), or soy protein isolate (SPI) to BC and evaluated for their physiochemical stability, in vitro cytotoxicity, and cellular uptake by Caco-2 cells. The particle diameters of the BC loaded nanoparticles with 0.75% SC or 1.0% WPI emulsifiers were 75 and 90 nm, respectively. Mean particle diameters of three BC loaded nanoparticle nanoemulsions increased less than 10% at 4 °C while they increased more at 25 °C (10-76%) during 30 days of storage. The oxidative stability of BC loaded nanoparticles encapsulated by proteins decreased in the following order: SC > WPI > SPI. The retention rates of BC in nanoparticles were 63.5%, 60.5%, and 41.8% for SC, WPI, and SPI, respectively, after 30 days of storage at 25 °C. The BCs chemical stability was improved by increasing the concentration of protein. Both the rate of particle growth and the total BC loss at 25 °C were larger than at 4 °C. The color of BC loaded nanoparticles decreased with increasing storage in the dark without oxygen, similar to the decrease in BC content of nanoparticles at 4 and 25 °C. Almost no cytotoxicity due to BC loaded nanoparticles cellular uptake was observed, especially when diluted 10 times or more. The uptake of BC was significantly improved through nanoparticle delivery systems by 2.6-, 3.4-, and 1.7-fold increase, respectively, for SC, WPI, and SPI, as compared to the free BC. The results of this study indicate that protein stabilized, BC loaded nanoparticles can improve stability and uptake of BC.

Hepatic Gene Expression Related to Lower Plasma Cholesterol in Hamsters Fed High-Fat Diets Supplemented with Blueberry Peels and Peel Extract

This study analyzed plasma lipid profiles, genes related to cholesterol and bile acid metabolism, and inflammation in liver as well as adipose tissue from Syrian Golden hamsters fed high-fat diets supplemented with blueberry (BB) pomace byproducts including 8% dried whole blueberry peels (BBPWHL), 2% dried extract of peels (BBPX; 95% ethanol extract), and 6% residue from extracted peel (BBPEXT) compared to a diet containing 5% (w/w) microcrystalline cellulose (control). All BB diets significantly lowered plasma very low density lipoprotein cholesterol and total cholesterol concentrations. Interestingly, BB diets increased fecal lipid excretion. Hepatic CYP7A1 expression was up-regulated by all BB diets, and the expression of CYP51 was up-regulated by BBPX and BBPEXT diets, suggesting that both bile acid and cholesterol synthesis were increased. No significant changes in adipocyte gene expression related to inflammatory markers were observed with any BB diet. These data suggest that hepatic modulation of bile acid and cholesterol synthesis primarily contributes to the cholesterol-lowering effect of BB pomace byproducts.