scholarly journals Differentiation of Adsorptive and Viscous Effects of Dietary Fibres on Bile Acid Release by Means of In Vitro Digestion and Dialysis

2018 ◽  
Vol 19 (8) ◽  
pp. 2193 ◽  
Author(s):  
Susanne Naumann ◽  
Ute Schweiggert-Weisz ◽  
Stephanie Bader-Mittermaier ◽  
Dirk Haller ◽  
Peter Eisner
Keyword(s):  
Bile Acid ◽  
Bile Acids ◽  
Dry Matter ◽  
Taurocholic Acid ◽  
Viscous Effects ◽  
Dietary Fibres ◽  
High Fibre ◽  
Dialysis Method ◽  
Acid Release

To explain the cholesterol-reducing effects of dietary fibres, one of the major mechanisms proposed is the reduced reabsorption of bile acids in the ileum. The interaction of dietary fibres with bile acids is associated with their viscous or adsorptive effects. Since these fibre characteristics are difficult to investigate in vivo, suitable in vitro methodologies can contribute to understanding the mechanistic principles. We compared the commonly used centrifugal approach with a modified dialysis method using dietary fibre-rich materials from different sources (i.e., barley, citrus, lupin, and potato). Digestion was simulated in vitro with oral, gastric, and small intestinal digestion environments. The chyme was dialysed and released bile acids were analysed by high-performance liquid chromatography. The centrifugation method showed adsorptive effects only for cholestyramine (reference material) and a high-fibre barley product (1.4 µmol taurocholic acid/100 mg dry matter). Alternatively, the dialysis approach showed higher values of bile acid adsorption (2.3 µmol taurocholic acid/100 mg dry matter) for the high-fibre barley product. This indicated an underestimated adsorption when using the centrifugation method. The results also confirmed that the dialysis method can be used to understand the influence of viscosity on bile acid release. This may be due to entrapment of bile acids in the viscous chyme matrix. Further studies on fibre structure and mechanisms responsible for viscous effects are required to understand the formation of entangled networks responsible for the entrapment of the bile acids.

scholarly journals Retention of Primary Bile Acids by Lupin Cell Wall Polysaccharides Under In Vitro Digestion Conditions

Nutrients ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 2117 ◽  
Author(s):  
Naumann ◽  
Schweiggert-Weisz ◽  
Haller ◽  
Eisner
Keyword(s):  
Cell Wall ◽  
Bile Acid ◽  
Bile Acids ◽  
Molecular Interactions ◽  
Enterohepatic Circulation ◽  
In Vitro Digestion ◽  
Adsorptive Capacity ◽  
Cell Wall Polysaccharides ◽  
Dietary Fibres

Interference of dietary fibres with the enterohepatic circulation of bile acids is proposed as a mechanism for lowering cholesterol. We investigated how lupin hull and cotyledon dietary fibres interact with primary bile acids using an in vitro model under simulated upper gastrointestinal conditions. Cell wall polysaccharides were isolated and extracted to separate pectin-like, hemicellulosic, and lignocellulosic structures. Lupin hull consisted mainly of structural components rich in cellulose. The viscosity of the in vitro digesta of lupin hull was low, showing predominantly liquid-like viscoelastic properties. On the other hand, lupin cotyledon fibre retarded bile acid release due to increased viscosity of the in vitro digesta, which was linked with high contents of pectic polymers forming an entangled network. Molecular interactions with bile acids were not measured for the hull but for the cotyledon, as follows: A total of 1.29 µmol/100 mg DM of chenodesoxycholic acids were adsorbed. Molecular interactions of cholic and chenodesoxycholic acids were evident for lignin reference material but did not account for the adsorption of the lupin cotyledon. Furthermore, none of the isolated and fractionated cell wall materials showed a significant adsorptive capacity, thus disproving a major role of lupin cell wall polysaccharides in bile acid adsorption.

scholarly journals Mechanisms of Interactions between Bile Acids and Plant Compounds—A Review

2020 ◽  
Vol 21 (18) ◽  
pp. 6495
Author(s):  
Susanne Naumann ◽  
Dirk Haller ◽  
Peter Eisner ◽  
Ute Schweiggert-Weisz
Keyword(s):  
Bile Acid ◽  
Bile Acids ◽  
Molecular Mechanisms ◽  
Hydrophobic Interactions ◽  
Future Research ◽  
Bile Acid Metabolism ◽  
Dietary Fibres ◽  
Research Activities ◽  
Plant Compounds

Plant compounds are described to interact with bile acids during small intestinal digestion. This review will summarise mechanisms of interaction between bile acids and plant compounds, challenges in in vivo and in vitro analyses, and possible consequences on health. The main mechanisms of interaction assume that increased viscosity during digestion results in reduced micellar mobility of bile acids, or that bile acids and plant compounds are associated or complexed at the molecular level. Increasing viscosity during digestion due to specific dietary fibres is considered a central reason for bile acid retention. Furthermore, hydrophobic interactions are proposed to contribute to bile acid retention in the small intestine. Although frequently hypothesised, no mechanism of permanent binding of bile acids by dietary fibres or indigestible protein fractions has yet been demonstrated. Otherwise, various polyphenolic structures were recently associated with reduced micellar solubility and modification of steroid and bile acid excretion but underlying molecular mechanisms of interaction are not yet fully understood. Therefore, future research activities need to consider the complex composition and cell-wall structures as influenced by processing when investigating bile acid interactions. Furthermore, influences of bile acid interactions on gut microbiota need to be addressed to clarify their role in bile acid metabolism.

scholarly journals Hepatitis D Virus Entry Inhibitors Based on Repurposing Intestinal Bile Acid Reabsorption Inhibitors

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 666
Author(s):  
Michael Kirstgen ◽  
Kira Alessandra Alicia Theresa Lowjaga ◽  
Simon Franz Müller ◽  
Nora Goldmann ◽  
Felix Lehmann ◽  
...  
Keyword(s):  
Bile Acid ◽  
Taurocholic Acid ◽  
Hek293 Cells ◽  
Acid Uptake ◽  
Hepatitis D ◽  
Entry Inhibitors ◽  
Ic50 Values ◽  
Bile Acid Transporter ◽  
Acid Transporter

Identification of Na+/taurocholate co-transporting polypeptide (NTCP) as high-affinity hepatic entry receptor for the Hepatitis B and D viruses (HBV/HDV) opened the field for target-based development of cell-entry inhibitors. However, most of the HBV/HDV entry inhibitors identified so far also interfere with the physiological bile acid transporter function of NTCP. The present study aimed to identify more virus-selective inhibitors of NTCP by screening of 87 propanolamine derivatives from the former development of intestinal bile acid reabsorption inhibitors (BARIs), which interact with the NTCP-homologous intestinal apical sodium-dependent bile acid transporter (ASBT). In NTCP-HEK293 cells, the ability of these compounds to block the HBV/HDV-derived preS1-peptide binding to NTCP (virus receptor function) as well as the taurocholic acid transport via NTCP (bile acid transporter function) were analyzed in parallel. Hits were subsequently validated by performing in vitro HDV infection experiments in NTCP-HepG2 cells. The most potent compounds S985852, A000295231, and S973509 showed in vitro anti-HDV activities with IC50 values of 15, 40, and 70 µM, respectively, while the taurocholic acid uptake inhibition occurred at much higher IC50 values of 24, 780, and 490 µM, respectively. In conclusion, repurposing of compounds from the BARI class as novel HBV/HDV entry inhibitors seems possible and even enables certain virus selectivity based on structure-activity relationships.

scholarly journals Evaluating Hepatobiliary Transport with 18F-Labeled Bile Acids: The Effect of Radiolabel Position and Bile Acid Structure on Radiosynthesis and In Vitro and In Vivo Performance

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Stef De Lombaerde ◽  
Ken Kersemans ◽  
Sara Neyt ◽  
Jeroen Verhoeven ◽  
Christian Vanhove ◽  
...  
Keyword(s):  
Bile Acid ◽  
Bile Acids ◽  
Membrane Vesicles ◽  
Hepatic Uptake ◽  
Hepatobiliary Transport ◽  
Bile Acid Transporters ◽  
Significant Difference ◽  
The Impact

Introduction. An in vivo determination of bile acid hepatobiliary transport efficiency can be of use in liver disease and preclinical drug development. Given the increased interest in bile acid Positron Emission Tomography- (PET-) imaging, a further understanding of the impact of 18-fluorine substitution on bile acid handling in vitro and in vivo can be of significance. Methods. A number of bile acid analogues were conceived for nucleophilic substitution with [18F]fluoride: cholic acid analogues of which the 3-, 7-, or 12-OH function is substituted with a fluorine atom (3α-[18F]FCA; 7β-[18F]FCA; 12β-[18F]FCA); a glycocholic and chenodeoxycholic acid analogue, substituted on the 3-position (3β-[18F]FGCA and 3β-[18F]FCDCA, resp.). Uptake by the bile acid transporters NTCP and OATP1B1 was evaluated with competition assays in transfected CHO and HEK cell lines and efflux by BSEP in membrane vesicles. PET-scans with the tracers were performed in wild-type mice (n=3 per group): hepatobiliary transport was monitored and compared to a reference tracer, namely, 3β-[18F]FCA. Results. Compounds 3α-[18F]FCA, 3β-[18F]FGCA, and 3β-[18F]FCDCA were synthesized in moderate radiochemical yields (4–10% n.d.c.) and high radiochemical purity (>99%); 7β-[18F]FCA and 12β-[18F]FCA could not be synthesized and included further in this study. In vitro evaluation showed that 3α-FCA, 3β-FGCA, and 3β-FCDCA all had a low micromolar Ki-value for NTCP, OATP1B1, and BSEP. In vivo, 3α-[18F]FCA, 3β-[18F]FGCA, and 3β-[18F]FCDCA displayed hepatobiliary transport with varying efficiency. A slight yet significant difference in uptake and efflux rate was noticed between the 3α-[18F]FCA and 3β-[18F]FCA epimers. Conjugation of 3β-[18F]FCA with glycine had no significant effect in vivo. Compound 3β-[18F]FCDCA showed a significantly slower hepatic uptake and efflux towards gallbladder and intestines. Conclusion. A set of 18F labeled bile acids was synthesized that are substrates of the bile acid transporters in vitro and in vivo and can serve as PET-biomarkers for hepatobiliary transport of bile acids.

scholarly journals Downregulation of CTRP-3 by Weight Loss In Vivo and by Bile Acids and Incretins in Adipocytes In Vitro

2020 ◽  
Vol 21 (21) ◽  
pp. 8168
Author(s):  
Andreas Schmid ◽  
Jonas Gehl ◽  
Miriam Thomalla ◽  
Alexandra Hochberg ◽  
Anja Kreiß ◽  
...  
Keyword(s):  
Weight Loss ◽  
Bile Acid ◽  
Bile Acids ◽  
Serum Levels ◽  
Receptor Expression ◽  
Low Calorie Diet ◽  
Calorie Diet ◽  
Bile Acid Receptor

The adipokine CTRP-3 (C1q/TNF-related protein-3) exerts anti-inflammatory and anti-diabetic effects. Its regulation in obesity and during weight loss is unknown. Serum and adipose tissue (AT) samples were obtained from patients (n = 179) undergoing bariatric surgery (BS). Moreover, patients (n = 131) participating in a low-calorie diet (LCD) program were studied. CTRP 3 levels were quantified by ELISA and mRNA expression was analyzed in AT and in 3T3-L1 adipocytes treated with bile acids and incretins. There was a persistent downregulation of CTRP-3 serum levels during weight loss. CTRP-3 expression was higher in subcutaneous than in visceral AT and serum levels of CTRP-3 were positively related to AT expression levels. A rapid decrease of circulating CTRP-3 was observed immediately upon BS, suggesting weight loss-independent regulatory mechanisms. Adipocytes CTRP-3 expression was inhibited by primary bile acid species and GLP 1. Adipocyte-specific CTRP-3 deficiency increased bile acid receptor expression. Circulating CTRP-3 levels are downregulated during weight loss, with a considerable decline occurring immediately upon BS. Mechanisms dependent and independent of weight loss cause the post-surgical decline of CTRP-3. The data strongly argue for regulatory interrelations of CTRP-3 with bile acids and incretin system.

Interaction between bile acids and staphylococcal polysaccharide: inhibition of capsule formation in encapsulated mutant strains (taurine+, taurine−) of Staphylococcus aureus

1983 ◽  
Vol 29 (12) ◽  
pp. 1653-1660 ◽  
Author(s):  
Toshichika Ohtomo
Keyword(s):  
Staphylococcus Aureus ◽  
Bile Acid ◽  
Bile Acids ◽  
Cholic Acid ◽  
Taurocholic Acid ◽  
Polysaccharide Antigen ◽  
Capsule Formation ◽  
Mutant Strains ◽  
Bile Acid Derivatives ◽  
Capsular Material

In a previous paper, we showed that bile acid derivatives inhibit capsule formation as well as taurine biosynthesis in a taurine+ (Tau+) encapsulated strain of Staphylococcus aureus. In the present study, binding of [14C]cholic acid ([14C]CA) and [14C]taurocholic acid ([14C]TA) to the staphylococcal polysaccharide antigen (SPA) of the capsular fraction was examined. The bile acids were found to bind with SPA via taurine of the Tau+ cells. [14C]CA bound with the SPA fraction of the Tau+ strain within 10–30 min, whereas 60–120 min was required in the binding of [14C]TA. Various bile acids competed with cholic acid binding to Tau+ cells which was shown by the inhibition of binding with cholic acid or taurocholic acid but not with glycholic acid. Binding of bile acid derivatives to a Tau− encapsulated mutant or to capsular material from this mutant was not observed.

Bile Acid Synthesis in the Developing Sheep Liver

1973 ◽  
Vol 45 (3) ◽  
pp. 403-406
Author(s):  
R. A. Smallwood ◽  
P. Jablonski ◽  
J. McK. Watts
Keyword(s):  
Bile Acid ◽  
Bile Acids ◽  
Placental Transfer ◽  
Umbilical Vein ◽  
Acid Synthesis ◽  
Taurocholic Acid ◽  
Secondary Bile Acid ◽  
Radioactive Label ◽  
Sheep Liver ◽  
Conjugated Bile Acids

1. [14C]Cholesterol was administered intravenously via the umbilical vein to foetal sheep in the latter half of gestation, and the incorporation of radioactive label into foetal bile acids was assessed. 2. After 4 days, 0·5–2% of the radioactive label was found in foetal bile. Seventy to eighty per cent of the radioactive label in foetal bile was present as [14C]taurocholic acid and [14C]taurochenodeoxycholic acid. The remainder was [14C]cholesterol. No radioactive label was found in taurodeoxycholic acid, or in any of the glycine-conjugated bile acids. 3. It is concluded that the foetal sheep liver in the second half of gestation synthesizes taurocholic acid and taurochenodeoxycholic acid. However, the secondary bile acid taurodeoxycholic acid and the glycine-conjugated bile acids, present in foetal bile, have been acquired by placental transfer from the mother.

EFFECT OF ADRENALECTOMY ON BILE ACIDS IN RATS

1964 ◽  
Vol 46 (3) ◽  
pp. 405-408 ◽  
Author(s):  
Antti Telkkä ◽  
Toini Lahikainen ◽  
A. N. Kuusisto
Keyword(s):  
Bile Acid ◽  
Thin Layer ◽  
Bile Acids ◽  
Thin Layer Chromatography ◽  
Acid Concentration ◽  
Taurocholic Acid ◽  
Ductus Choledochus ◽  
Layer Chromatography

ABSTRACT The effect of adrenalectomy on taurocholic acid, the main bile acid of the rat, was studied. The bile was obtained by cannulation from the ductus choledochus. The concentration of taurocholic acid in the bile was determined using thin-layer chromatography. The taurocholic acid concentration in the bile of the adrenalectomized animals was significantly decreased, being about a half that of the control rats. The results are briefly discussed.

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