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The impetus for this study is the limited amount of information on performance characteristics of food science-encompassing online bibliographic databases. Database usage is an important element in modern research because a comprehensive understanding of current knowledge is essential for effective, unbiased hypothesis formulation and testing. Six databases commonly recommended by academic libraries for information retrieval in the food sciences (Academic Search Premier [ASP], Agricultural Online Access [AGRICOLA], CAB Direct, Food Science and Technology Abstracts [FSTA], PubMed, and Web of Science [WoS]) were compared in a case study based on the research topic "in vitro bile acid binding properties of dietary lignin." A complex string of search terms was used for citation retrieval, and predetermined inclusion/exclusion criteria were used to determine the relevancy of retrieved articles. Searching WoS and CAB Direct returned the greatest number of relevant articles, followed closely by FSTA, PubMed, and AGRICOLA. FSTA and AGRICOLA returned the highest ratios of relevant-to-irrelevant articles, followed closely by CAB Direct. None of the databases, when used alone, recovered all of the relevant articles identified in the study; WoS indexed the highest percentage of relevant articles identified (WoS = 10; total = 19). WoS also had the highest number of relevant articles that were unique to any one database. The thoroughness of searching the complete group of databases was tested by comparison of retrieved citations with those found in relevant review articles, revealing the need for testing overall inclusivity. PRACTICAL APPLICATION: Comprehensive online information retrieval is the most efficient means of accessing current knowledge. Awareness of current knowledge is essential for effective, unbiased decision making in private sector and academic/government-based research endeavors. Thus, online database usage is an essential element of modern food science research. This paper provides tangible examples of the performance characteristics of online bibliographic databases commonly recommended for information retrieval in the food sciences. The paper is written so as to aid the reader in making decisions with respect to database usage for the recovery of topic-relevant peer-reviewed articles germane to their area of research.

This study evaluated the hypocholesterolemic effects and potential metabolism of single and combined administrations of capsaicinoids and Lactobacillus plantarum SWUN5815 in ovariectomized rats. Forty female Sprague-Dawley rats were divided into 5 treatment groups. One group was sham-operated (with 1 mL/100 g BW physiological saline), and the 4 other groups were double-ovariectomized: OVX-CON (with 1 mL/100 g BW physiological saline), OVX-CAP (with 1 mL/100 g BW physiological saline and fed with food containing 0.08 g/kg capsaicinoids), OVX-L. P. (with 1 mL 2 × 109 cfu/mL/100 g BW L. plantarum SWUN5815), and OVX-CAP + L. P. (with 1 mL 2 × 109 cfu/mL/100 g BW L. plantarum SWUN5815 and fed with food containing 0.08 g/kg capsaicinoids). Rats were sacrificed after 6 weeks of feeding. Results showed that the combination of capsaicinoids and L. plantarum significantly decreased the total cholesterol, triglyceride and low-density lipoprotein cholesterol of plasma, total cholesterol and lipid accumulation of liver in ovariectomized rats without affecting food intake. Bile acid contents in the fecal excrement and small intestines were significantly increased by the combination compared with the individual effects. However, the mRNA levels of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA R), farnesoid X receptor (FXR), ileum bile acid binding protein (IBABP), and apical sodium-dependent bile acids transporter (ASBT) significantly decreased. Liver X receptor also remarkably increased. Therefore, these genes potentially affect cholesterol metabolism by inhibiting cholesterol synthesis and promoting excretion of bile acid. The protective effects of the combination of capsaicinoids and L. plantarum SWUN5815 on the intestines were significant in ovariectomized rats.

Dandelion (Taraxacum officinale) var. Garnet Stem was harvested from Texas and New Jersey for identification, quantification of phytochemicals, measurement of free radical scavenging activity, and bile acid binding capacity. The red midrib and petioles were extracted with methanol or ethanol and with or without water in combination with four different acids such as formic, hydrochloric, acetic, and citric acid. LC‐ESI‐HR‐QTOF‐MS was used to identify four anthocyanins including cyanidin‐3‐glucoside, cyanidin‐3‐(6‐malonyl)‐glucoside (A‐1), cyanidin‐3‐(6‐malonyl)‐glucoside (A‐2), and peonidin‐3‐(malonyl)‐glucoside for the 1st time. In New Jersey samples, vitamin C and β‐carotene were highest in the leaf blades versus whole leaf and petioles. Samples from Texas had highest amount of lutein, violaxanthin, and chlorophyll a and b in leaf blades versus whole leaf and petioles. Maximum DPPH free scavenging activity was found in MeOH: water: acid (80:19:1) and the combination of FA with EtOH: water: acid (80:19:1) demonstrated the higher level of total phenolic. Among six bile acids, sodium chenodeoxycholate was bound maximum in both Texas and New Jersey samples. This is the first report of anthocyanin identification from the midvein and petiole of Garnet Stem dandelion and results suggested that the phytochemicals and nutrients are highest in the leaf but may vary the amount depending on harvest location. Four anthocyanins in the red midrib and petioles of Garnet Stem could be a potential source for antioxidants and can be used as a source of natural food color.

The valorization of guava waste requires compositional and functional studies. We tested three byproducts of guava puree processing, namely refiner, siever, and decanter. We analyzed the chemical composition and quantified the prebiotic activity score and selected carbohydrates; we also determined the water holding (WHC), oil holding (OHC), cation exchange capacities, bile acid binding, and glucose dialysis retardation (GDR) of the solid fraction and the antioxidative and α‐amylase inhibitory capacities (AIC) of the ethanolic extract. Refiner contained 7.7% lipid, 7.08% protein and a relatively high phytate content; it had a high prebiotic activity score and possessed the highest binding capacity with deoxycholic acid. Siever contained high levels of low molecular weight carbohydrates and total tannin but relatively low crude fiber and cellulose contents. It had the highest binding with chenodeoxycholic acid (74.8%), and exhibited the highest 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging capacity. Decanter was rich in cellulose and had a high prebiotic activity score. The WHC and OHC values of decanter were within a narrow range and also exhibited the highest binding with cholic acid (86.6%), and the highest values of GDR and AIC. The refiner waste could be included in animal feed but requires further processing to reduce the high phytate levels. All three guava byproducts had the potential to be a source of antioxidant dietary fiber (DF), a finding that warrants further in vivostudy. To differing extents, the guava byproducts exhibited useful physicochemical binding properties and so possessed the potential for health‐promoting activity. These byproducts could also be upgraded to other marketable products so the manufacturers of processed guava might be able to develop their businesses sustainably by making better use of them.

The bile acid binding capacity of wheat bran with different particle sizes was determined. Unmilled wheat bran with an average particle size of 900 μm (WB-900), milled wheat bran at two particle sizes, 500 and 200 μm (WB-500 and WB-200), and all three bran samples washed with water (WWB-900, WWB-500, and WWB-200) were mixed with bile acids at pH 6.3 to determine their in vitro adsorption capacity. On a dry matter basis, the order of relative bile acid binding values was WB-900 ∼ WB-500 > WWB-900 > WB-200 > WWB-500 > WWB-200. Data suggests that the surface area as measured by the Brunauer–Emmett–Teller (BET) method and water holding capacity may significantly affect the bile acid binding capacity of wheat bran. As the BET surface area increased with decreasing particle size, the water holding capacity and bile acid binding decreased. Bile acid binding capacity of wheat bran appears to be linked to the ability of the samples to physically adsorb the bile acids. Bile acid binding capacity significantly decre...

Membrane binding by cytosolic fatty acid binding proteins (FABP) appears to constitute a key step of intracellular lipid trafficking. We applied NMR spectroscopy to study the partitioning of a water-soluble bile acid binding protein (BABP), belonging to the FABP family, between its free and lipid-vesicle-bound states. As the lipid-bound protein was NMR-invisible, the signals of the free biomolecule were analyzed to obtain quantitative information on binding affinity and steady-state kinetics. The data indicated a reversible interaction of BABP with anionic vesicles occurring in a very slow exchange regime on the NMR time scale. The approximate binding epitope was demonstrated from results on BABP samples in which different positively charged lysine residues were mutated to neutral alanines. H/D exchange measurements indicated a higher exposure to solvent for the core amino acid residues in the liposome-bound state. Finally, the BABP-liposome interaction was also investigated for the first time through an MRI-chemical exchange saturation transfer experiment that has potential applications not only in the field of biology, but also in biomedicine, bioanalytical chemistry, and nanotechnology.

Little is known about the hypolipidemic activity of okra; therefore, we investigated the hypolipidemic activity of okra and its interaction with gene expression of several key components involved in lipid homeostasis. Male C57BL/6 mice were randomly divided into three groups and fed with hyperlipidemic diet or two hyperlipidemic diets supplemented with 1% or 2% okra powder for eight weeks. Results demonstrated that okra dose-dependently decreased serum and hepatic total cholesterol and triglyceride, and enhanced fecal excretion of bile acids. Gene expression analysis revealed that okra upregulated cholesterol 7α-hydroxylase (CYP7A1) expression, downregulated expression of sterol regulatory element-binding protein 1c (SREBP1c) and fatty acid synthase (FAS), with no effect on sterol regulatory element-binding protein 2 (SREBP2), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), low-density lipoprotein receptor (LDLR) and carnitine palmitoyltransferase-1A (CPT1A). It was suggested that hypolipidemic activity of okra was mediated most likely by upregulation of cholesterol degradation through CYP7A1 and by inhibition of lipogenesis through SREBP1c and FAS. Okra raw and fractionated polysaccharide showed strong bile acid binding capacity in vitro, which may contribute to the hypolipidemic activity observed. In conclusion, okra has potential application in the management of hyperlipidemia and its associated metabolic disorders.

The presence of a disulfide bridge in liver bile acid binding protein (L-BABP/S-S) allows for site-selective binding of two bile acids, glycochenodeoxycholic (GCDA) and glycocholic acid (GCA), differing only in the presence of a hydroxyl group. The protein form devoid of the disulfide bridge (L-BABP) binds both bile salts without discriminating ability. We investigate the determinants of the molecular recognition process in the formation of the heterotypic L-BABP/S-S complex with GCDA [corrected] and GCA [corrected] located in the superficial and inner protein sites, respectively. The comparison of the NMR spectroscopy structure of heterotypic holo L-BABP/S-S, the first reported for this protein family, with that of the homotypic L-BABP complex demonstrates that the introduction of a S-S link between adjacent strands changes the conformation of three key residues, which function as hot-spot mediators of molecular discrimination. The favoured χ(1) rotameric states (t, g(+) and g(-) for E99, Q100 and E109 residues, respectively) allow the onset of an extended intramolecular hydrogen-bond network and the consequent stabilisation of the side-chain orientation of a buried histidine, which is capable of anchoring a specific ligand.

Water-soluble β-glucan (BG) extracted from a high-BG oat line was treated with different amounts of lichenase (1→3)(1→4)-β-d-glucanase) enzyme to yield three different molecular weight (MW) BG extracts. Low (LMW-BG, 157,000), medium (MMW-BG, 277,000), and high (HMW-BG, 560,000) MW BG extracts were added to plain muffin formulations at a level of 0.52% (0.42% in the batter, 0.52% in the resultant muffins) to investigate the effect of MW of BG on textural and bile acid (BA) binding properties of the muffins. In addition, treatments were prepared containing LMW-BG, MMW-BG, and HMW-BG extracts in amounts providing equivalent batter firmness as determined on a texture analyzer. Resultant BG concentrations (and per serving amounts) of these muffins were 1.36% (0.81 g/60 g muffin), 1.05% (0.63 g/60 g muffin), and 0.52% (0.31 g/60 g muffin), respectively; thus, the LMW treatment complied with a U.S. Food and Drug Administration health claim requiring 0.75 g of BG per serving. The firmness, springiness, a...

Summary Whole oat flour, N979-5-2-4 (N979), IA95111 (IA95), ‘Jim’ and ‘Paul’ with β-glucan concentration of 8.6%, 7.6%, 5.3%, and 5.9%, respectively, was made into extruded breakfast cereal (EBC). EBC β-glucan had greater peak molecular weight than corresponding whole oat flour. Both whole oat flour and EBC from N979 and IA95 had greater peak viscosity (PV), as measured using a Rapid ViscoAnalyser, than that from Jim or Paul. Bile acid binding of EBC, correlated with total β-glucan concentrations and PV, was either similar or greater than that of corresponding whole oat flour. Jim EBC had the least expansion ratio, lowest brown colour and cereal aroma but greatest tooth packing values. Paul and N979 EBC, although different from each other in a few sensory attributes, had similar acceptability as judged from a consumer test, suggesting that oats with elevated β-glucan concentrations can be successfully incorporated into EBC with minimal processing alterations.

The folding initiation mechanism of human bile acid-binding protein (BABP) has been examined by 19F NMR. Equilibrium unfolding studies of BABP labeled with fluorine at all eight of its phenylalanine residues showed that at least two sites experience changes in solvent exposure at high denaturant concentrations. Peak assignments were made by site-specific 4FPhe incorporation. The resonances for proteins specifically labeled at Phe17, Phe47, and Phe63 showed changes in chemical shift at denaturant concentrations at which the remaining five phenylalanine residues appear to be fully solvent-exposed. Phe17 is a helical residue that was not expected to participate in a folding initiation site. Phe47 and Phe63 form part of a hydrophobic core region that may be conserved as a site for folding initiation in the intracellular lipid-binding protein family.

Muffins containing different amounts and molecular weights (MW) of β-glucan were evaluated for the effect of β-glucan on the physical characteristics of the muffins and on in vitro bile acid binding and fermentation with human fecal flora. Wheat flour muffins were prepared with the addition of β-glucan extracts with high-, medium-, or low-MW. For oat flour muffins, the native oat flour contained high-MW β-glucan; the oat flours were treated to create medium- and low-MW β-glucan within the prepared muffin treatments. For each 60-g muffin, the amounts of β-glucan were 0.52, 0.57, and 0.59 g for high-, medium-, and low-MW β-glucan wheat flour muffins, and 2.38, 2.18, and 2.23 g for high-, medium-, and low-MW β-glucan oat flour muffins, respectively. The lower the MW of the β-glucan in muffins, the lower the height and volume of the muffins. The oat flour muffins were less firm and springy than the wheat flour muffins as measured on a texture analyzer; however, MW had no effect on muffin texture. The...

Health benefits of consuming whole grains are reduced risk of heart disease, stroke, and cancer. The U.S. Health and Human Services and USDA dietary guidelines recommend consumption of 6–10 oz of grain products daily and one-half of that amount should contain whole grains. Whole grains contain vitamins, minerals, fiber, and phytonutrients. Bile-acid-binding capacity has been related to cholesterol lowering potential of food fractions. Lowered recirculating bile acids results in utilization of cholesterol to synthesize bile acid and reduced fat absorption. Secondary bile acids have been associated with increased risk of cancer. Bile-acid-binding potential has been related to lowering the risk of heart disease and that of cancer. It has been reported that bile-acid-binding of wheat bran is not related to its total dietary fiber (TDF) content. Whole (W) grain as well as pearled (P) hard red winter wheat (Hrw), hard white winter wheat (Hww), and durum wheat (DU) cooked grains were evaluated for in vi...

A study was conducted to determine bioactivities of flaxseed (Linum usitatissimum L.; variety: Valour) proteins and their hydrolysates. Isolated flaxseed proteins were treated with Flavourzyme® at different levels of enzyme to substrate ratio (E/S) and hydrolysis time. The unhydrolysed proteins and hydrolysates were studied for angiotensin I-converting enzyme inhibiting (ACEI) activity, hydroxyl radical (OH·) scavenging activity and bile acid binding ability. Flavourzyme catalysed hydrolysis generated hydrolysates with a 11.94–70.62% degree of hydrolysis (DH). The hydrolysates (0.67 mg/ml) had strong ACEI activity (71.59–88.29%). The maximum ACEI activity containing hydrolysate exhibited an IC50 of 0.07 mg/ml (E/S: 1.5; Time: 12 h; DH: 11.94%). The OH· scavenging activity of the hydrolysates (0.5 mg/ml) was 12.48–22.08% with an IC50 of 1.56 mg/ml in the sample possessing maximum activity (E/S: 47.5; Time 0.7 h; DH: 24.63%). Both these activities were greater in hydrolysates with lower DH and higher peptide chain length (PCL) than those with higher DH and lower PCL. Hydrolysed flaxseed proteins (0.67 mg/ml) had no bile acid binding ability. The unhydrolysed proteins had no ACEI or OH· scavenging activity but demonstrated bile acid binding ability.

The in vitro binding of bile acids of milled wheat bran (MWB) and milled extruded wheat bran (MEB) at five specific mechanical energy (SME) levels of 120 (MEB-120), 177 (MEB-177), 234 (MEB-234), 291 (MEB-291), and 358 (MEB-358) Whr/kg on a fat-free dry weight basis was determined using a mixture of bile acids secreted in human bile at duodenal physiological pH 6.3. Relative to cholestyramine (bile acid binding, cholesterol lowering drug) in vitro bile acid binding capacity on dry matter, total dietary fiber (TDF), and insoluble dietary fiber (IDF) basis was for MWB: 21, 43, 45%; the range for MEB was 18–21%, 34–41%, and 36–43%, respectively. MWB resulted in significantly higher bile acid binding than that of MEB at 120, 234, and 291 Whr/kg on a dry matter, TDF, and IDF basis. These results demonstrate the relative health-promoting potential of MWB = MEB-177 = MEB-358 > MEB-120 = MEB-234 = MEB-291 as indicated by the bile acid binding on a dry matter basis. Data suggest that significant improvemen...

The in vitro binding of bile acids of extruded wheat bran (EWB) at five specific mechanical energy (SME) levels of 120 (EWB-120), 177 (EWB-177), 234 (EWB-234), 291 (EWB-291), and 358 (EWB-358) Wh/kg on a dry weight basis, was determined using a mixture of bile acids secreted in human bile at a duodenal physiological pH 6.3. Experiments were conducted using six treatments and two blank incubations to test unextruded and extruded wheat bran samples on an equal dry matter (DM) basis. Relative to cholestyramine (bile acid binding, cholesterol-lowering drug), in vitro bile acid binding ability of unextruded and extruded wheat bran treatments on an equal DM basis was 14–23%. The bile acid binding ability of the total dietary fiber (TDF) was 28–51% and insoluble dietary fiber (IDF) was 29–53%. Bile acid binding on DM, TDF, and IDF bases for EWB-177 was significantly (P ≤ 0.05) higher, and EWB-358 was significantly lower than UWB, EWB-120, EWB-234, and EWB-291. Bile acid binding for EWB-120 was significa...

OBJECTIVE: Antacids are used worldwide for the treatment of acid-related conditions such as heartburn and gastro-esophageal reflux disease. The present study investigated the in vitro acid neutralization and bile acid binding capacities of hydrotalcite compared with other antacids that are available in Germany and China. It has been reported that hydrotalcite is effective in the treatment of bile reflux gastritis because of its binding capacity to bile acids. METHODS: Hydrotalcite and other preparations of antacids were tested in a comparative in vitro study. The neutralization properties were determined with static and dynamic tests (preliminary antacid test, acid neutralization capacity (ANC) test, Rossett-Rice (RR) test) and the bile acid binding test with a standardized commercial test kit (Merckotest bile acids). RESULTS: In the static and dynamic tests hydrotalcite 500 mg and some other antacids, such as magaldrate, almasilate, algedrate Mg hydroxide, Ca/Mg carbonate and calcium carbonate, demonstrated favorable ANC reflected by rapid onset and long duration of action, and high buffering capacity. In the RR test, a hydrotalcite dose of 1000 mg was able to keep the pH level above 3 for 76.9 min. The bile acid binding capacity test yielded that hydrotalcite had the highest binding potential to taurodeoxycholic acid, a lipophilic bile acid associated with cell and mucosa toxicity. CONCLUSIONS: Hydrotalcite has a rapid onset of action, a high buffering capacity and a long duration of action. In particular, hydrotalcite binds cytotoxic bile acids. These pharmacochemical properties make hydrotalcite a most suitable antacid.

The in vitro bile acid binding by rice bran, oat bran, dehulled barley, and β-glucan enriched barley was determined using a mixture of bile acids at a duodenal physiological pH of 6.3. Six treatments and two blank incubations were conducted testing substrates on an equal protein basis. The relative in vitro bile acid binding of the cereal brans on an equal total dietary fiber (TDF) and insoluble dietary fiber (IDF) basis considering cholestyramine as 100% bound was rice bran 45 and 49%; oat bran 23 and 30%; dehulled barley 33 and 57%; and β-glucan enriched barley 20 and 40%, respectively. Bile acid bindings on equal protein basis for the respective cereals were 68, 26, 41, and 49%. Bile acid binding by rice bran may account to a great extent for its cholesterol-lowering properties, while bile acid binding by oat bran suggests that the primary mechanism of cholesterol lowering by oat bran is not due to the bile acid binding by its soluble fiber. Bile acid binding was not proportional to the solubl...

Bile acids are generated in vivo from cholesterol in the liver, and they undergo an enterohepatic circulation involving the small intestine, liver, and kidney. To understand the molecular mechanism of this transportation, it is essential to gain insight into the three-dimensional (3D) structures of proteins involved in the bile acid recycling in free and complexed form and to compare them with homologous members of this protein family. Here we report the solution structure of the human ileal lipid-binding protein (ILBP) in free form and in complex with cholyltaurine. Both structures are compared with a previously published structure of the porcine ILBP-cholylglycine complex and with related lipid-binding proteins. Protein structures were determined in solution by using two-dimensional (2D)- and 3D-homo and heteronuclear NMR techniques, leading to an almost complete resonance assignment and a significant number of distance constraints for distance geometry and restrained molecular dynamics simulations. The identification of several intermolecular distance constraints unambiguously determines the cholyltaurine-binding site. The bile acid is deeply buried within ILBP with its flexible side-chain situated close to the fatty acid portal as entry region into the inner ILBP core. This binding mode differs significantly from the orientation of cholylglycine in porcine ILBP. A detailed analysis using the GRID/CPCA strategy reveals differences in favorable interactions between protein-binding sites and potential ligands. This characterization will allow for the rational design of potential inhibitors for this relevant system.

Scope: The molecular mechanisms underlying the cholesterol-lowering properties of oats are only partly known. To study possible pathways involved, we investigated gene expressions in the liver and small intestine of mice fed oats. Method and results: Cholesterol and bile acids were analyzed in plasma and feces from LDL-receptor deficient (LDLr-/-) mice fed Western diet with wholegrain oats. A transcriptome analysis of mRNA from liver and jejunum was performed together with quantitative RT-PCR. Oat-fed mice had lower levels of plasma lipids and increased levels of bile acids and cholesterol in feces compared with controls. Two hundred thirty nine genes in jejunum and 25 genes in liver were differentially expressed (FDR corrected p < 0.05). The most affected biological process in jejunum was lipid biosynthesis and regulation. The apical sodium-dependent bile acid transporter (ASBT, Slc10a) and the intracellular bile acid binding protein (Fabp6) were both upregulated, whereas small heterodimer partner-1 (Shp-1) and apolipoprotein CII (Apoc2) were downregulated. Conclusions: Whole oats attenuated responses typically induced by high-fat diet. Increased expression of genes for intestinal bile acid uptake following oat consumption suggests retention in the gut lumen rather than decreased uptake capacity as cause for the increased bile acid excretion and the concomitant reduction of plasma cholesterol. (Less)

We compared the vasorelaxant action of nine different bile acids and correlated their vasorelaxant activity with their individual indices for hydrophobicity or lipophilicity. Vasorelaxant activity correlated with the relative lipid solubility of bile acids with lipophilic bile acids exhibiting the greatest vasorelaxant activity with modest to no vasorelaxant activity exhibited by hydrophilic bile acids. We also investigated whether bile acid-induced vasorelaxation is mediated by antagonism of a prototypal contractile receptor, the alpha(1)-adrenoceptor, by stimulation of a bile acid surface membrane receptor, by the release of endothelium-derived relaxant factors, by promoting the generation of reactive oxygen species and increasing the extent of lipid peroxidation, or by modifying membrane fluidity. Lipophilic bile acids induce vasorelaxation possibly by antagonizing alpha(1)-adrenoceptors, a phenomenon that manifests itself as a lowering of the affinity of vascular alpha(1)-adrenoceptors. Bile acid-induced vasorelaxation was not dependent upon stimulation of a bile acid surface membrane receptor or the release of endothelium-derived relaxant factors. Lipophilic bile acids can also increase the extent of lipid peroxidation with a subtle reduction in the fluidity of rat vascular smooth muscle membranes not associated with loss of membrane cholesterol or phospholipid. We have concluded that lipophilic bile acids are non-selective vasorelaxants whose mechanism of action is a multifaceted process involving antagonism of contractile surface membrane receptors possibly effected by an increased extent of lipid peroxidation and/or membrane fluidity but occurs independent of the release of endothelial-derived relaxant factors or stimulation of a surface membrane bile acid binding site.

The in vitro bile acid binding by rice, oat, wheat, and corn brans was determined using a mixture of bile acids normally secreted in human bile at a physiological pH of 6.3. The objective of the study was to relate bile acid binding of cereal brans to health promoting properties. Three experiments were conducted testing substrates on an equal weight (dry matter) basis, an equal total dietary fiber (TDF) basis, and an equal TDF and equal fat basis. Each experiment was repeated to validate the results (for a total of six experiments). The relative in vitro bile acid binding of the cereal brans on an equal TDF basis considering cholestyramine as 100% bound was rice bran 51%, wheat bran 31%, oat bran 26%, and corn bran 5%. The data suggest that cholesterol lowering by rice bran appears to be related to bile acid binding. The primary mechanism of cholesterol lowering by oat bran may not be due to bile acid binding by soluble fiber. Bile acid binding did not appear to be proportional to the soluble fib...

Background: A 14 kDa protein is a major rat ileal cytosolic bile acid-binding protein (14 kDa I-BABP). This report describes the nor- mal and glucocorticoid-accelerated postnatal expression of 14 kDa I-BABP. Methods: 14 kDa I-BABP and its mRNA were detected by antiserum and antisense cRNA probe, respectively, in ileum and ovary from 7-, 14-, 21-, 28-, and 35-day-old rats. Results: A positive histochemical reaction with 14 kDa I-BABP antiserum was found in cytosol of ileal enterocytes and ovarian luteal cells at 21 and 35 days of age, respectively. Likewise, Northern blot analysis indicated that the cRNA probe hybridized to a single transcript of 500 bp in total cellular RNA prepared from the ileum of 21-day-old and ovary of 35-day-old rats. Corticosteroid treatment resulted in a histochemical reaction in ileum of 14-day-old animals as compared to the appearance of this reaction in 21- day-old control littermates. Similarly, Northern blot analysis detected the earlier appearance of mRNA levels in corticosteroid-treated animals (11 days vs. 17 days in control animals). Conclusions: 14 kDa I-BABP and its mRNA are normally expressed in rat ileum at 17 days of postnatal life. 14 kDa I-BABP is expressed considerably later in rat ovary. Corticosteroid treatment results in precocious expres- sion of ileal 14 kDa I-BABP.

A study involving measurement and analysis of adsorption of common bile acids, namely cholic, deoxycholic, and lithocholic acids, on cereal type dietary fibers was conducted. The selected food fibers were oat fiber, rice fiber, barley fiber, corn bran, and wheat bran, which are all extensively used in processed foods. The adsorption data were measured at 37C and 25C, which correspond to approximate human body and room temperatures. Influence of particle size reduction, due to grinding, on a fiber's bile acid binding capacity was examined by using macro size (35-60 mesh) and micro size (100-300 mesh) fibers as adsorbents. The investigation also included the effects of medium pH and the chemical composition. The experimental data were correlated with the Langmuir and the Freundlich isotherms in order to utilize the data in future predictions and simulations. It was found that the particle size reduction, accompanied by surface area increase, has a significant influence on the adsorption capacity of the fiber. Macro size fibers adsorbed the same bile acid with the following trend: oat > barley > rice > wheat > corn; while micro size fibers followed a somewhat different trend: rice > barley > oat > wheat > corn. This was due to the surface area change after grinding, and a positive correlation between the surface area and the adsorption capacity was observed in each case. The adsorption was favored by acid pH surroundings, and it was positively correlated with the hydrophobicity of the bile acid. In all cases, the bile acids were adsorbed on the same fiber with the following trend: lithocholic acid > deoxycholic acid > cholic acid. Fibers adsorbed more bile acid at 25C than they did at 37C. However, the increase in the uptake capacities were not very signifiant.

Forty patients with familial hypercholesterolaemia (FH) were treated with 40 mg pravastatin once daily. Pravastatin decreased serum total and low density lipoprotein cholesterol (LDL) after 8 weeks of treatment by 28% and 33%, respectively, while high density lipoprotein cholesterol increased by 8% and triglycerides decreased by 14%. In 30 patients LDL cholesterol had not decreased below 5.0 mmol l-1 after 8 weeks of treatment, and in these patients resins were added to pravastatin, resulting in an additional decrease in total and LDL cholesterol of 8% and 12%, respectively. A control group of 22 FH patients was treated with placebo for 10 weeks, after which time resins were added, and they induced a decrease in total and LDL-cholesterol of 17% and 22%, respectively. Our results over a 24-week treatment period indicate that 40 mg pravastatin is more effective than 3 packets of resins in lowering LDL cholesterol, whereas the combination is most effective of all and can be used safely.

Bile acid (BA) hydrophobicity, evaluated by the octanol-water partition coefficient, decreases along the series deoxycholic acid - chenodeoxycholic acid - hyodeoxycholic acid - ursodeoxycholic acid - cholic acid (CA) - ursocholic acid (UCA). In vitro experiments carried out using dialysis techniques (to determine the maximum BA binding) and ultrafiltration of plasma pre-incubated with 0.1 mM BA (to assess the distribution of BA between the different lipoprotein fractions) showed that the maximum binding of BA to plasma and lipoproteins follows the same order of hydrophobicity. The fraction not bound to proteins, greater with the hydrophilic BA (UCA and CA), is distributed in the lipoprotein fractions and in particular in high density lipoproteins.

Fiber, when fed to animals or man, will generally cause increased excretion of bile acids. The level of bile acid excretion appears to be a function of the structure of the fiber. Fiber binds bile acids and bile salts in vitro. The extent of binding is characteristic for each type of fiber and each substrate. Bile acid binding may be one mechanism of the physiological action of fiber.