Therapeutic Effects of Different Animal Bile Powders on Lipid Metabolism Disorders and Their Composition Analysis.

OBJECTIVE: To compare the therapeutic effect of different animal bile powders on lipid metabolism disorders induced by high-fat diet in rats, and analyze the bioactive components of each animal bile powder. METHODS: Sixty Sprague-Dawley rats were randomly divided into 6 groups (n=10): normal diet control group, high-fat diet model group, high-fat diet groups orally treated with bear, pig, cow and chicken bile powders, respectively. Serum biochemical markers from the abdominal aorta in each group were analyzed. Changes in the body weight and liver weight were recorded. Pathohistological changes in the livers were examined. High performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry was used to determine the composition of bioactive components in each animal bile powder. RESULTS: Treatment with different types of animal bile powders had different inhibitory effects on high-fat diet-induced increase of body weight and/or liver weight in rats, most notably in bear and pig bile powders (P<0.05). High-fat diet induced lipid metabolism disorder in rats, which could be reversed by treatment with all kinds of bile powders. Bear bile and chicken bile showed the most potent therapeutic effect against lipid metabolism disorder. Cow and bear bile effectively alleviated high-fat diet induced liver enlargement and discoloration, hepatocyte swelling, infiltration of inflammatory cells and formation of lipid vacuoles. Bioactive component analysis revealed that there were significant differences in the relative content of taurocholic acid, taurodeoxycholic acid and ursodeoxycholic acid among different types of animal bile. Interestingly, a unique component with molecular weight of 496.2738 Da, whose function has not yet been reported, was identified only in bear bile powder. CONCLUSIONS: Different animal bile powders had varying therapeutic effect against lipid metabolism disorders induced by high-fat diet, and bear bile powder demonstrated the most effective benefits. Bioactive compositions were different in different types of animal bile with a novel compound identified only in bear bile powder.

A combination of three plasma bile acids as a putative biomarker for schizophrenia.

The aim of the present study is to determine whether plasma bile acids (BAs) could be used as an auxiliary diagnostic biomarker to distinguish patients with schizophrenia from healthy controls. Seventeen different BAs were quantitatively measured in plasma of 12 healthy participants and 12 patients with schizophrenia. Then, the data were subjected to correlation and linear discriminant analysis (LDA). The concentrations of cholic acid (CA), taurochenodeoxycholic acid (TCDCA) and taurodeoxycholic acid (TDCA) were significantly decreased in plasma of the schizophrenia patients. Correlation analysis showed the concentrations of CA, TCDCA and TDCA were negatively correlated with schizophrenia. In addition, LDA demonstrated that combination of CA, TCDCA and TDCA with a classification formula could predict correctly classified cases and the accuracy of prediction was up to 95.83%. Combination of the three BAs may be useful to diagnose schizophrenia in plasma samples.

X-ray characterization of self-assembled long-chain phosphatidylcholine/bile salt/silica mesostructured films with nanoscale homogeneity.

A bile salt (sodium taurodeoxycholate, NaTDC) was used to prevent phase separation between silica and lipid in self-assembled long-chain diacyl phosphatidylcholine/SiO(2) films. Phase diagrams for NaTDC/didecanoyl phosphatidylcholine/SiO(2) and NaTDC/egg phosphatidylcholine/SiO(2) films were investigated through grazing-incidence small-angle X-ray scattering at a synchrotron source.

Single-step analysis of individual conjugated bile acids in human bile using 1H NMR spectroscopy.

1H and 13C NMR spectra of intact human bile were assigned using one-dimensional (1H and 13C) and two-dimensional (1H-1H and 1H-13C) experiments. Individual conjugated bile acids--glycocholic acid, glycodeoxycholic acid, glycochenodeoxycholic acid, taurocholic acid, taurodeoxycholic acid, and taurochenodeoxycholic acid--were identified. The bile acids were quantified accurately and individually in a single step by using distinct and characteristic amide signals. Making use of 13C NMR, the study also suggests a way to analyze unconjugated bile acids separately, if present. Chemical shift assignments and rapid single-step analysis of individual conjugated bile acids from intact bile presented herein may have immense utility in the study of bile acid metabolism and deeper understanding of hepatobiliary diseases.

Measurement of bile acid in serum and bile with arylamine-glass-bound 3alpha-hydroxysteroid dehydrogenase and diaphorase.

3Alpha-hydroxysteroid dehydrogenase (3-HSD) from Pseudomonas testosteroni and diaphorase (lipoyl dehydrogenase) from Clostridium spp. have been immobilized individually onto arylamine glass beads through diazotization. A cost-effective enzymic colorimetric method for determination of bile acid in serum and bile employing a mixture of these immobilized enzymes was developed. The method is based on measurement of reduced nicotinamide adenine dinucleotide generated from bile acid in serum/bile by immobilized 3alpha-HSD with a color reagent consisting of nitro blue tetrazolium chloride salt, oxidized nicotinamide adenine dinucleotide, and immobilized lipoyl dehydrogenase in 0.065 M sodium phosphate buffer, pH 7.0. Analytical recovery of added bile acid (50 and 200 micromol/L) was 95.57 and 85.46% in serum and 97.6 and 91.6% in bile, respectively. Within- and between-batch coefficients of variation (CV) for bile acid determination were <1.2 and <0.2% in serum and >0.1 and <0.1% in bile, respectively. Good correlations for bile acid in serum (r1=0.92) and in bile (r2=0.97) were obtained by use of a standard chemical method and the present method. The mixture of immobilized 3alpha-HSD dehydrogenase and lipoyl dehydrogenase lost 50% of its initial activity after 6 months of regular use. The cost of bile acid determination in 100 serum and bile samples by the present method has been compared with that of the Sigma kit method.

Gallbladder dysfunction enhances physical density but not biochemical metastability of biliary vesicles.

The gallbladder role in cholesterol gallstone pathogenesis occurs through modulation of bile cholesterol metastability. The present study characterized the effects of concentrating bile on cholesterol crystallization through vesicle transformation, crystal habits, and potentiation of effector substances. Supersaturated model biles with total lipid concentrations of 12, 9, 6, and 3 g/dl were prepared with identical molar ratios (taurocholate-egg yolk phosphatidylcholine-cholesterol: 71:18:11). Bile metastability was assessed spectrophotometrically, and morphology of vesicle and crystal was sequentially scanned by video-enhanced differential contrast microscopy. The effects of replacing 30% of egg yolk phosphatidylcholine with soy bean phosphatidylcholine, 30% of taurocholate with taurodeoxycholate or tauroursodeoxycholate, and addition of concanavalin A-binding glycoprotein on each model bile were examined. By lowering total lipid concentration, cholesterol crystallization was retarded with less fusion and aggregation of vesicles. The effects of substances promoting cholesterol crystallization were enhanced with lesser bile. By replacing 30% of taurocholate with tauroursodeoxycholate, cholesterol crystallization was markedly inhibited in all concentrations, forming stable liquid-crystals. Impaired water absorption by the gallbladder may stabilize vesicles and inhibit rapid cholesterol crystallization, but the potential of cholesterol crystallization effector substances must be modified to alter bile cholesterol metastability.

Steroid metabolism along the gastrointestinal tract of the cannulated pig.

Steroid metabolism along the gastrointestinal tract of the cannulated pig was studied. Thi was achieved by fitting simple gut cannulas in the terminal ileum, caecum and mid-colon of three Landrace x large white boars, which enabled convenient collection of digesta and faecal samples at defined time points. Biochemical analyses showed that the neutral steroid profile of the pig is similar to that of man, dominated by cholesterol and its bacterial metabolite coprostanol. In contrast, pigs consuming a normal diet excrete appreciably lower quantities of neutral sterols in faeces. The major primary bile acids detected were the glycine and taurine amidates of hyocholic and chenodeoxycholic acids, which were rapidly converted to the free bile acids and subsequently dehydroxylated to hyodeoxycholic and lithocholic acids respectively, in the terminal ileum and caecum. Bacterial deconjugation and 7 alpha-dehyrdoxylation are virtually complete in the caecum with negligible further metabolism in the colon and faeces. On a wet weight basis the concentration of both neutral and acid steroids was shown to increase aborally. Inclusion of dietary fibre in the form of cellulose (Solka floc) and guar gum reduced steroid concentration considerably at all sites of the large intestine, which is consistent with their stool bulking effects. In conclusion, this study shows that intestinal steroid metabolism in the pig is similar to that in man despite slightly different bile acid profiles and, therefore, the multicannulated pig may serve as a useful model of man in chemoprevention studies of colorectal cancer.

Taurohyodeoxycholic acid protects against taurochenodeoxycholic acid-induced cholestasis in the rat.

The prevention of the hepatotoxic effects produced by intravenous infusion of taurochenodeoxycholic acid (TCDCA) by coinfusion with taurohyodeoxycholic acid (THDCA) was evaluated in bile fistula rats; the hepatoprotective effects of the latter were also compared with those of tauroursodeoxycholic acid (TUDCA). Rats infused with TCDCA at a dose of 8 micromol/min/kg showed reduced bile flow and calcium secretion, as well as increased biliary release of alkaline phosphatase (AP) and lactate dehydrogenase (LDH). This was associated with a very low biliary secretion rate of TCDCA (approximately 1 micromol/min/kg). Simultaneous infusion of THDCA or TUDCA at the same dose preserved bile flow and almost totally abolished the pathological leakage of the two enzymes into bile. The effect was slightly more potent for THDCA. The maximum secretion rate of TCDCA increased to the highest value (8 micromol/min/kg) when coinfused with either of the two hepatoprotective bile acids (BA), which were efficiently and completely secreted in the bile, without metabolism. Calcium output was also restored and phospholipid (PL) secretion increased with respect to the control saline infusion. This increase was higher in the THDCA study. These data show that THDCA is highly effective in the prevention of hepatotoxicity induced by intravenous infusion of TCDCA by facilitating its biliary secretion and reducing its hepatic residence time; this was associated with selective stimulation of PL biliary secretion.

The role of calcium ions and bile salts on the pancreatic lipase-catalyzed hydrolysis of triglyceride emulsions stabilized with lecithin.

Lecithin-stabilized triglyceride emulsions are subject to hydrolysis by pancreatic lipase. The time profiles of these reactions are characterized by a lag-phase and a zero-order phase. Lag phases are more pronounced with long-chain triglycerides. Ca2+ is effective in reducing the lag-phase and activating lipase. Kinetic analysis of the reactions suggests that, like previous findings by others, taurodeoxycholate (TDC) micellar solutions combine with the lipase-colipase complex to form another catalytically active enzyme form. This enzyme form exhibits reduced activity in the absence of Ca2+. In the presence of Ca2+ the mixed micelle-lipase complex becomes more active and opens a new pathway for lipolysis. It is suggested that this enzyme form can bind more easily to interfaces with different physicochemical properties. Under these conditions, Ca2+ activates the lipolysis of short-, medium-, and long-chain triglycerides by a similar mechanism. Maximum activities were measured in the presence of approximately 6 mM TDC and 30 mM Ca2+. The experimental conditions approximate the physiological conditions in the gastrointestinal tract since all of the factors studied here have been reported to be necessary for in vivo lipolysis and/or absorption of triglycerides. A mechanistic model for lipolysis in the presence of Ca2+ and the bile salt TDC is proposed which accounts for most of the experimental observations in a quantitative manner.

A model for micellar aggregates of a bile salt: crystal structure of sodium taurodeoxycholate monohydrate.

Crystals of sodium taurodeoxycholate monohydrate, NaC26H44NO6S X H2O, are trigonal, space group P3(1), with a = 18.393(1), c = 7.097(1)A, V = 2079.3(5)A3, and Z = 3. The structure was solved by direct methods and Fourier techniques and refined by full-matrix least-squares calculations. The final R index is 0.051. The side chair of the anion displays an approximate folded-back conformation. The cyclopentane ring assumes an intermediate conformation between the half-chain and the beta-envelope. The sodium ion shows a distorted octahedral coordination with six oxygen atoms, giving rise to ion-ion and ion-dipole interactions. The molecules form helices, characterized by threefold screw axes, with a radius of about 16 A. The helices are packed in such a way as to be embedded in each other as cog-wheels. The helix found in this crystal structure will be used as a model and checked in the study of the micellar solutions of sodium taurodeoxycholate, following the same strategy satisfactorily employed in the case of sodium deoxycholate.

High performance liquid-chromatographic analysis of individual bile acids: free, glycine- and taurine-conjugated bile acids.

High performance liquid-chromatographic analyses of individual bile acids (cholic acid, chenodeoxycholic acid, deoxycholic acid, and lithocholic acid), free and conjugated with glycine and taurine, are described. The analyses of free and glycine-conjugated bile acids are based on esterification of carboxyl group of bile acids with O-(p-nitrobenzyl)-N, N'-diisopropylisourea (PNBDI). Moreover, ursodeoxycholic acid, hyocholic acid, hyodeoxycholic acid and 3beta-hydroxy-5-cholenoic acid also are able to analyse by this method. These bile acids in biological sample were extracted by an Amberlite XAD-2 column, and separated by DEAE-Sepharose CL-6B into free, glycine- and taurine-conjugated bile acids. After the separation, free and glycine-conjugated bile acids were esterified with PNBDI directly. Because taurine-conjugated bile acids are unable to be esterified with PNBDI, these bile acids were hydrolyzed by NaOH in order to make free bile acids, and then they were esterified. Because the p-nitrobenzyl ester of bile acids has characteristic ultraviolet absorption, these compounds were separated to individual bile acids by high performance liquid-chromatography, and detected by an UV-detector. An analysis of individual bile acids in human bile was demonstrated.