Bile Acid Binding Properties Research Articles

Studies on the partial characterization of extracted glycosaminoglycans from fish waste and its potentiality in modulating obesity through in-vitro and in-vivo.

Glycosaminoglycans (GAGs) are bioactive polysaccharides or glycoconjugates found in the fish waste having significant health impacts. In the present study it has been attempted to extract GAGs from mackerel fish waste through chemical and enzymatic methods. Further, the extracted GAGs (e-GAGs) were analyzed for their composition (uronic acid, total sugar & sulfate), chemical characterization was carried out through techniques of scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) & Proton NMR. Further, probable major GAGs present was identified by enzymatic digestion. The biological potential of the extracted glycoconjugate was assessed further through in-vitro and in-vivo studies. In-vitro biological activity showed good lipase inhibition (IC50, 2.6mg/mL) and bile acid binding properties (dose-dependent). Lipid accumulation lowered in the e-GAGs differentiated 3T3L1 preadipocyte cells have also been observed. The high fat fed animal (in-vivo) study showed ameliorative effect via reducing blood sugar∼1.28↓, lipid profile↓, plasma insulin∼3.5↓, improved glucose tolerance, and homeostatic model assessment for insulin resistance (HOMA-IR, ∼3.0↓). Furthermore, elimination of bile acid (BA) due to GAG-BA binding properties resultant in removal of elevated fecal triglyceride and cholesterol suggesting its lipid lowering activity. Regulation of various proteins linked to carbohydrate and lipid metabolism including fatty acid synthase (FAS), low density lipoproteins receptor (LDL-R), 7α-hydroxylase, glucose transporter-4 (GLUT4) and Peroxisome proliferator- activated receptor gamma (PPAR-γ) were significant (p < 0.05) with e-GAGs treatment when compared to HFD group. Thus, the e-GAGs showed potential hypolipidemic activity through elimination of bile acid binding property together with regulating the specific protein related to obesity and its associated complications.

In vitro and in vivo evaluation of the bile acid-binding properties of dried persimmon and its non-extractable proanthocyanidin fraction

Dried persimmons contain abundant insoluble tannins comprised of non-extractable proanthocyanidins (NEPAs). To determine the beneficial function of NEPAs, we studied the bile acid-binding ability of NEPAs using in vitro and in vivo experiments. For the in vitro evaluation, 70% (v/v) acetone-insoluble solids (AIS) with different NEPA levels was prepared from persimmon fruits during drying. AIS with higher NEPA levels displayed stronger bile acid-binding activity, and the highest NEPA levels can be obtained from mostly-dried fruits. The in vivo bile acid-excreting effect of dried persimmon powder (DP) and AIS was verified by feeding experiments using C57BL/6J mice. The average bile acid-excretion was in order of low-fat group (1.07 µmol/day) < high-fat (HF) group (3.03 µmol/day) < HF + AIS group (4.44 µmol/day) < HF + DP group (6.74 µmol/day). These results suggest that the bile acid-excreting function of the fruit is related to the presence of NEPAs, which are constitutive ingredients of dried persimmon.

Physicochemical and Biological Properties of Polysaccharides from Dictyophora indusiata Prepared by Different Extraction Techniques.

In this study, different extraction techniques, including traditional hot water extraction (HWE), microwave-assisted extraction (MAE), pressurized assisted extraction (PAE), and ultrasonic-assisted extraction (UAE), were used to extract Dictyophora indusiata polysaccharides (DFPs), and their physicochemical and biological properties were compared. Results revealed that extraction yields of D. indusiata polysaccharides prepared by different extraction techniques ranged from 5.62% to 6.48%. D. indusiata polysaccharides prepared by different extraction techniques possessed similar chemical compositions and monosaccharide compositions, while exhibited different molecular weights (Mw), apparent viscosities, and molar ratios of constituent monosaccharides. In particularly, D. indusiata polysaccharides prepared by HWE (DFP-H) had the highest Mw and apparent viscosity among all DFPs, while D. indusiata polysaccharides extracted by UAE (DFP-U) possessed the lowest Mw and apparent viscosity. In addition, the in vitro antioxidant effects of D. indusiata polysaccharides prepared by PAE (DFP-P) and DFP-U were significantly higher than that of others. Indeed, both DFP-P and DFP-H exhibited much higher in vitro binding properties, including fat, cholesterol, and bile acid binding properties, and lipase inhibitory effects than that of D. indusiata polysaccharides prepared by MAE (DFP-M) and DFP-U. These findings suggest that the PAE technique has good potential for the preparation of D. indusiata polysaccharides with desirable bioactivities for the application in the functional food industry.

Inhibition of low-density lipoprotein oxidation, antioxidative and bile acid-binding capacities of hydrolyzed proteins from carbohydrase-treated oat bran.

This study investigated the valorization of oat bran and the use of its proteins to generate polypeptides with antioxidant and bile acid-binding properties. Ten protein hydrolysates were prepared by treating cellulase (CPI) or Viscozyme (VPI) protein isolates with five proteases. VPI-pepsin was the best peroxyl radical scavenger (497±6-μM Trolox equivalents [TE]/g) while VPI-Flavourzyme quenched hydroxyl radicals (28±0.6) and VPI-pepsin superoxide anion radicals (45.3±6.6%). Hydrolysates, except those produced with pepsin, dose-dependently chelated iron whereas VPI-Protamex had the best copper-chelating capacity (59.83±1.40%). These antioxidative capacities were important in preventing by 50% in vitro copper-induced oxidation of human low-density lipoprotein. Furthermore, due to their aromatic amino acid contents and hydrophobicity, the hydrolysates bound up to 46.3% the bile acids taurodeoxycholate and taurocholate. PRACTICAL APPLICATIONS: The presence of oxidants in foods can damage food molecules and decrease their quality. They are also known to increase the risk of developing chronic conditions like cardiovascular disease. Finding new antioxidant molecules are therefore useful in the management of chronic diseases. Data from this work showed that hydrolyzed oat bran proteins can be useful in stabilizing commercial oil as they reduced the oxidation of peanut oil. Additionally, the protein hydrolysates not only prevented the oxidation of linoleic, a common component of both vegetable oils and biological cell membranes, they also inhibited the oxidation of human LDL cholesterol and chelated bile acids. These hydrolysates can then be further explored as multifunctional ingredients for the development of stable functional food products with potential beneficial effects on the cardiovascular system.

Information Retrieval in Food Science Research II: Accounting for Relevance When Evaluating Database Performance.

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.

Bioassay Guided Isolation of Polysaccharide Rich Fraction from Myrmecodia Platytyrae and its Bile Acid Binder Property

Bioassay guided isolation was done on the Myrmecodia platytyrae (MyP) extracts in order to find the best extract that can bind with bile acid. The function of bile acid binder is to reduce the reabsorption of bile acid in the intestine so that it will cause the decrease of cholesterol in the blood circulation. The extraction process was started by using different organic solvent such as hexane, toluene, ethyl acetate, ethanol and water. All extracts were tested its bile acid binding properties and the extract gave out highest activity was selected to be fractionated. The result showed that water extract has highest bile acid binding property (75%). Then, fractionation process was performed in order to find the best fraction from water extract that have bile acid binding property. The sub-fractionation processes were continued and the process only focussed to the fraction that has highest bile acid binding property until a white powder with 97.02 % carbohydrate was obtained. The powder was subjected to FTIR and was found to have glycosidic bond as shown by bands at 1141 until 1018 cm-1 which is a character of polysaccharide. The polysaccharide rich fraction was hydrolysed and subjected to HPLC to identify its monosaccharide groups. The result showed the presence of glucose and fructose were found to be among the major monosaccharides. This result suggested that the polysaccharide from MyP water extract with high bile acid binding property was gluco-fructan.&#x0D;

Gelling and bile acid binding properties of gelatin-alginate gels with interpenetrating polymer networks by double cross-linking

Interpenetrating polymer network (IPN) is an effective method to improve functional properties of hydrogels by forming cross-linking networks. In this study, the gelatin-alginate gels formed by the combination of enzymatic and ionic cross-linking were called IPN gels. Meanwhile, the gels with the treatment of only transglutaminase (TG) or Ca2+ were named as G-semi-IPN and A-semi-IPN, respectively. The formation of semi-IPN and IPN was confirmed by studies on rheology, thermodynamics and micro-morphology. The results showed that the IPN gels had improved gelling properties and structural stability. The functional properties of different gelatin-alginate gels were also investigated. It was firstly found that the IPN gels could enhance mechanical properties, decrease swelling capacity and had better bile acid binding capacity. These results of gelatin-alginate gels provide references and novel prospects of IPN for the application in the field of food industry.

Modified soluble dietary fiber from black bean coats with its rheological and bile acid binding properties

Alkaline hydrogen peroxide (AHP) was investigated to enhance the content and functionality of soluble dietary fiber (SDF) extracted from black bean coats. Compared with the content of SDF of original black bean coats 7.8%, the content of SDF of modified black bean coats was 16.9% after treated by 15% H2O2 (v/v) at pH 11 and 1:18 (w/v) as liquid-to-solid ratio for 0.5 h. Monosaccharide composition confirmed that the ratio of galacturonic acid in modified SDF (M-SDF) was higher than that of original SDF (O-SDF), and M-SDF was also with smaller molecular weight (Mw) of 1.24 × 106 Da and lower ζ-potential of −42.3 mV. Other structural characters were determined by FT-IR and TEM. In the range of 2–6% (w/v), both O-SDF and M-SDF showed a shear thinning behavior. The latter showed stronger gelation ability at the presence of Ca2+ evaluated by dynamic oscillatory rheometry. Moreover, M-SDF exhibited good abilities of binding bile acids in vitro. It could be concluded that M-SDF had a great potential to be applied as a novel kind of functional ingredient or additive in food industry.

Sevelamer in a diabetologist's perspective: a phosphate-binding resin with glucose-lowering potential.

Sevelamer is a calcium-free and metal-free phosphate-binding oral drug used in the management of hyperphosphataemia in chronic kidney disease. Preclinical and clinical trials have shown glucose and lipid-lowering effects of sevelamer, thereby giving rise to a potential role of the drug in the treatment of patients with type 2 diabetes. These 'novel' effects are most probably derived from the bile acid-binding properties of sevelamer. The proposed potential is supported by the approval of the bile acid sequestrant colesevelam in the United States for the treatment of type 2 diabetes and hypercholesterolaemia. This article offers a brief review on the effects of sevelamer and a perspective on the potential mechanisms behind the glucose-lowering effect of the drug.

Cholesterol reducing and bile-acid binding properties of taioba (Xanthosoma sagittifolium) leaf in rats fed a high-fat diet

The consumption of vegetables has been correlated with reduced risk of chronic non-communicable diseases due to the high fiber content and bioactive compounds found in vegetables. The arrowleaf elephant ear (Xanthosoma sagittifolium), which is known in Brazil as taioba, is a common plant in tropical America. Although its leafy portion possesses a high nutritional value, it is not widely consumed and has not been well studied. This study assessed the effect of lyophilised taioba leaf (LTL) as a hypolipidemic and prebiotic agent. Thirty-two Wistar rats were assigned to four groups: group 1 was fed a high-fat diet containing 3.67% (w/w) cellulose (low cellulose — LCEL); group 2 received a high-fat diet supplemented with 10% (w/w) cellulose (CEL); group 3 received a high-fat diet supplemented with 10% (w/w) inulin (INU); and group 4 was fed a high-fat diet supplemented with 28.4% LTL (TAI) to provide 10% (w/w) taioba fiber. The groups were fed their respective diets for 4weeks. The addition of LTL to the diet resulted in reduced weight gain, reduced liver fat, and increased fecal mass and lipid, in addition to higher fecal short chain fatty acid and bile salt concentrations, compared to the LCEL group. Additionally, only the TAI group exhibited a lower serum cholesterol concentration and a higher body ash content (p<0.05) than the LCEL group. Both the high bile salt binding capacity and high fermentability of LTL suggest that this plant may have a protective effect against cardiovascular diseases and bowel cancer.

Effects of Structural Modifications on Physicochemical and Bile Acid-Binding Properties of Psyllium

The effects of sulfation, hydroxypropylation, and succinylation on gelling, water uptake, swelling, and bile acid-binding capacities of psyllium were examined and compared at the same molar substitution degree. Sulfated, hydroxypropylated, and succinylated psyllium were prepared with substitution levels of 1.02, 0.88, and 0.79, respectively, and their structures were characterized using FT-IR, SEM, and ζ-potential determination. All three derivatization methods reduced the gelling and swelling capacities of psyllium and increased the water uptake and bile acid-binding capacities compared to the original psyllium. Interestingly, it was observed for the first time that introduction of a stronger negatively charged group into the molecule might more effectively enhance the bile acid-binding capacity of psyllium. On the other hand, the steric effect of the substitution groups seemed to be more critical in altering the gelling and swelling properties of psyllium.

Persimmon Fruit Tannin-Rich Fiber Reduces Cholesterol Levels in Humans

Bile acid-binding agents are known to lower blood cholesterol levels and have been clinically used for the treatment of hypercholesterolemia. We previously showed that tannin-rich fiber from young persimmon (Diospyros kaki) fruits had bile acid-binding properties. In this study, we performed a randomized, double-blind, placebo-controlled trial to investigate the hypocholesterolemic effects of tannin-rich fiber in humans. The subjects (n = 40, plasma total cholesterol levels 180–259 mg/dl) were divided into 3 groups and ingested cookie bars containing 0 g (placebo group, n = 14), 3 g (low-dose group, n = 13), or 5 g (high-dose group, n = 13) of tannin-rich fiber 3 times daily before meals for 12 weeks. Plasma total cholesterol levels decreased significantly in the low-dose (12 weeks, p < 0.005) and high-dose (6 weeks, p < 0.05; 12 weeks, p < 0.001) groups. In addition, plasma low-density lipoprotein cholesterol levels decreased significantly in the high-dose group (6 weeks, p < 0.05; 12 weeks, p < 0.001). These improvements were not accompanied by changes in plasma high-density lipoprotein cholesterol or plasma triglyceride levels. Our findings indicate that tannin-rich fiber from young persimmon fruits is a useful food material for treating hypercholesterolemia.

Preparation of succinylated derivatives of psyllium and their physicochemical and bile acid-binding properties

The succinyl psyllium derivatives were successfully prepared by reacting psyllium with succinic anhydride, 4-dimethylaminopyridine and tributylamine in N,N-dimethylformamide. Three succinyl psyllium derivatives with different degrees of substitution were prepared and denoted as S-Psy-L, S-Psy-M and S-Psy-H. FT-IR spectrum and 1H NMR of the succinylated psyllium showed that its monoester derivative, with succinyl groups, was formed successfully. The succinyl derivatives were also evaluated for their surface structure, gelling properties, water uptake capacities, swelling volumes, and bile acid-binding abilities in vitro. The results showed that succinylation significantly reduced the gelling properties and swelling ability of psyllium, as well as increased water uptake abilities and bile-acid binding capacities. The results of this study suggested that succinylation could be a potential approach for obtaining novel derivatives of psyllium with improved physicochemical and biological properties for application in functional foods or other consumer products.

Textural and Bile Acid‐Binding Properties of Muffins Impacted by Oat β‐Glucan with Different Molecular Weights

ABSTRACTWater‐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, and BA‐binding capacity of the muffins were unaffected by the MW of BG. However, when added at the maximum limit for equivalent batter firmness, the LMW treatment was more firm and less springy than the HMW treatment. Furthermore, BA‐binding capacities of LMW and MMW fractions tended to be greater than that of the HMW fraction when added at the maximum limit. These results add further evidence to the importance of fine‐tuning BG structure to provide maximum health benefits while maintaining high product quality.

Non-extractable Procyanidins and Lignin are Important Factors in the Bile Acid Binding and Radical Scavenging Properties of Cell Wall Material in some Fruits

The cell wall components and the food functions of alcohol-insoluble solids (AIS) of Chinese quince, quince, hawthorn, apple, pear and blueberry fruits were analyzed. Chinese quince contained characteristically high contents of cellulose, lignin, and non-extractable procyanidins (NEPCs). On the other hand, the quince AIS contained the highest proportion of NEPCs, the highest mean degree of polymerization (mDP), the strongest radical scavenging activity, and strong bile acid binding activity. In fruit AIS, the lignin and NEPC contents both showed positive correlations with the bile acid binding and radical scavenging activities. The value for mDP × NEPC content was a good index for the radical scavenging activity. The results suggest that highly polymerized NEPCs and lignin are important factors of cell wall components of fruits to having a high functionality, and Chinese quince and quince are interesting fruits from this view point.

Bile acid‐binding activity of young persimmon (Diospyros kaki) fruit and its hypolipidemic effect in mice

The hypolipidemic effects and bile acid-binding properties of young persimmon (Diospyros kaki) fruit were examined. In an animal experiment, male C57BL/6.Cr mice (n = 5) were fed an AIN-76-modified high fat diet supplemented with 2% or 5% (w/w) dried young persimmon fruit (YP) for 10 weeks. The intake of YP significantly enhanced fecal bile acid excretion and lowered the concentration of hepatic lipids and plasma cholesterol. Analysis of gene expression in liver tissue showed that 2% or 5% YP up-regulated the expression of the sterol regulatory element-binding protein-2 gene. In the 5% group, there were increased expressions of the genes for cholesterol 7alpha-hydroxylase and the low-density lipoprotein receptor. Next, the bile acid-binding ability of YP was analysed in vitro using cholic acid (CA). In 100-2000 microM CA solutions, 1% (w/v) YP adsorbed approximately 60% of CA, while dried mature persimmon fruit adsorbed approximately 20% of CA. The positive control, cholestyramine, adsorbed approximately 80% of CA in the 100-2000 microM CA solutions. A crude tannin extract from YP, which contained 54.7% condensed tannins, adsorbed approximately 78% of CA in the 2000 microM CA solutions. These results suggest that the ability of YP to bind bile acid contributes to its hypolipidemic effect in mice.

Sevelamer Hydrochloride (Renagel®), a Nonabsorbed Phosphate‐Binding Polymer, Does Not Interfere with Digoxin or Warfarin Pharmacokinetics

Sevelamer hydrochloride (Renagel) is a nonabsorbed phosphate-binding polymer marketed for the treatment of hyperphosphatemia in adult patients receiving hemodialysis. Sevelamer also exhibits bile acid-binding properties resulting in LDL cholesterol lowering. Potential drug interactions between digoxin and warfarin and sevelamer were studied. These two drugs were chosen because they are known to bind to the bile acid-binding polymers, cholestyramine and colestipol. Studies were single dose, crossover, with or without six 2.4 g doses of sevelamer. Plasma concentrations were determined using validated analytical methods. The pharmacokinetic profiles of digoxin and warfarin were not altered by the simultaneous and continued administration of sevelamer. Values for the ratio of ln[AUC(0-infinity)], ln[AUC(0-t)], and ln[Cmax] with and without sevelamer were close to 100%, and the 90% confidence intervals for these ratios were within the 80% to 125% range. It was concluded that sevelamer does not interfere with the absorption or excretion of digoxin or warfarin.

SK&F 97426-A: A Novel Bile Acid Sequestrant with Higher Affinities and Slower Dissociation Rates for Bile Acids in vitro Than Cholestyramine

SK&F 97426-A is a novel bile acid sequestrant that is threefold more potent than cholestyramine at increasing bile acid excretion in the hamster. SK&F 97426-A is a quaternary alkylammonium polymethacrylate that was selected for comparison with cholestyramine in vivo because of its superior in vitro bile acid binding properties. Association, dissociation, affinity, and capacity experiments were performed under physiologically relevant conditions with the most abundant bile acids found in human bile. The bile acids came to equilibrium with SK&F 97426-A and cholestyramine within ∼30min and 6 min, respectively. SK&F 97426-A and cholestyramine had similar capacities for all the bile acids (between 2.5 and 4mmol/g) and both had similar, very high affinities and slow dissociation rates for the dihydroxy bile acids. However, SK&F 97426-A had much higher affinities for the trihydroxy bile acids glycocholic acid and taurocholic acid than did cholestyramine. Dissociation of glycocholic acid and taurocholic acid from SK&F 97426-A was also much slower (27 and 25%, respectively, dissociated after 60 min) than from cholestyramine (89 and 84%, respectively, dissociated after 60 min). The higher affinities and slower dissociation rates of the trihydroxy bile acids for and from SK&F 97426-A probably account for the increased potency of SK&F 97426-A over cholestyramine in vivo.

SK&F 97426-A a more potent bile acid sequestrant and hypocholesterolaemic agent than cholestyramine in the hamster

SK&F 97426-A is a novel bile acid sequestrant which was selected for comparison with cholestyramine in vivo because of its superior in vitro bile acid binding properties. The effects of the two sequestrants on faecal bile acid excretion, plasma total cholesterol, VLDL + LDL and HDL cholesterol and triglyceride concentrations and on liver enzymes involved in the synthesis and metabolism of cholesterol were investigated in normocholesterolaemic hamsters. Four studies were conducted to determine the relative potencies of the two resins using a range of doses of the sequestrants over treatment periods of up to 2 weeks. Curves fitted to the resulting data allowed common maximum responses and separate ED 50s to be calculated for each sequestrant. The maximum response of both sequestrants was to increase bile acid excretion by 352% and lower plasma total cholesterol by 37–58%. LDL + VLDL and HDL cholesterol were reduced by 56–75% and 25–41%, respectively. SK&F 97426-A was 3 times more potent than cholestyramine at increasing the excretion of bile acids in the faeces and 2.1–3.4-fold and 2.3–3.2-fold more potent at lowering total plasma cholesterol and LDL plus VLDL cholesterol, respectively. In some of the experiments SK&F 97426-A was also more potent than cholestyramine at lowering HDL cholesterol. Plasma triglycerides were also lowered by both sequestrants by up to 31 % after 1 week but the relative potency could not be determined. These HDL cholesterol and total triglyceride lowering effects of bile acid sequestrants in the hamster are known not to occur in people treated with cholestyramine. There were minimal differences between hamsters treated for 1 or 2 weeks in the relative potencies or ED 50s calculated for the total plasma cholesterol, LDL + VLDL and HDL cholesterol. Both sequestrants may have been slightly more efficacious on these parameters after 2 weeks of treatment. Liver weights were reduced by about 15% by both sequestrants at 2% (w/w) in the diet for 1 week. The activities of the liver HMG-CoA reductase and cholesterol 7a-hydroxylase were increased as expected, whilst the activity of the acyl-CoA:cholesterol acyltransferase was reduced by both sequestrants at this dose. SK&F 97426-A was, therefore, 2–3-fold more potent as a bile acid sequestrant and hypocholesterolaemic agent than cholestyramine when tested in the hamster.

Identification of soybean protein components that modulate the action of insulin in vitro.

We have reported that a 37-kDa protein from a soybean isolate shows an affinity for bile acids and modulates insulin action on fat decomposition in vitro [Makino et al., Agric. Biol. Chem., 52, 803 (1988)]. In this study, the major components of the protein were identified as the acidic A1a and A2 subunits of glycinin, via amino-terminal sequence analyses of purified proteins and examination of their effects on fat decomposition in rat adipose cells. The most hydrophobic region of the subunits was found to be responsible for the bile acid-binding ability, and the binding region probably does not contribute to the insulin-modulating activity. These bile acid-binding and insulin-modulating properties were also noted in a 40-kDa protein from pea seeds, probably acidic subunits of legumin, suggesting that these characteristics may be common to legume proteins.