Room Temperature Phosphorescence of 1-Bromo-4-(bromoacetyl) naphthalene Induced by Sodium Deoxycholate

Sodium deoxycholate (NaDOC) could induce 1-bromo-4-(bromoacetyl) naphthalene (BBAN) to emit strong room temperature phosphorescence (RTP). Measurements of phosphore- scence spectra, peak intensity and polarization were used to investigate the solubilization of BBAN as a function of NaDOC concentration.

Mixed nanomicelles loaded with thymopeptides-sodium deoxycholate/phospholipid improve drug absorption

AIM: To improve the absorption of thymopeptides(TH) by preparing sodium deoxycholate/phospholipid-mixed nanomicelles(SDC/PL-MMs). METHODS: TH-SDC/PL-MMs were prepared by a film dispersion method, and then evaluated using photon correlation spectroscopy(PCS), zeta potential measurement, as well as their physical stability after storage for several days. Furthermore, in situ intestinal single-pass perfusion experiments and pharmacodynamics in immunodeficient mice were performed to make a comparison with TH powders and the control drug in absorption properties. RESULTS: A narrow size distribution of nanomicelles, with a mean particle size of(149 ± 8.32) nm and a zeta potential of(-31.05 ± 2.52) mV, was obtained. The in situ intestine perfusion experiments demonstrated a significant advantage in absorption characteristics for TH compared to the other formulations, and oral administration of TH-SDC/PL-MMs potentiated an equivalent effect with i.h. TH in pharmacodynamic studies in immunodeficient mice. CONCLUSIONS: TH-SDC/PL-MMs prepared by a film dispersion method are able to improve the absorption of TH. SDC/PL-MMs might be a good approach for the more effective delivery of drugs like TH.

Effect of Enzymes in Buccal Mucous Membrane on Buccal Absorption of Insulin

To evaluate the effect of proteolytic enzymes on the absorption of insulin in the buccal mucosa, the trichloroacetic acid (TCA) method was used to estimate the degradation of insulin under different conditions in the buccal mucosal homogenates. In vivo experiments estimating the enhancement of hypoglycaemic effect by enzyme inhibitors were also conducted. The results showed that proteolytic enzymes in the buccal mucosa were less active than in the intestine. Bacitracin, aprotinin and sodium deoxycholate could inhibit the degradation of insulin in the buccal mucosal homogenates. The degradation of insulin in buccal mucosal homogenates of normal hamsters was smaller than that of diabetic hamsters. In vivo experiments of hypoglycaemia supported the in vitro results. When given buccally, bacitracin, aprotinin and sodium deoxycholate could increase the relative pharmacological bioavailability of insulin. When co-administered with aprotinin(0.1%), bacitracin(0.5%) and sodium deoxycholate(5%), the relative pharmacological bioavailabilities of insulin were 4.84%, 6.60% and 14.95% respectively. The in vitro and in vivo results suggest that proteolytic enzymes are present in the buccal mucosa, which limit absorption of insulin. Co-administration with some enzyme inhibitors can improve the bioavailability of insulin via buccal delivery and sodium deoxycholte is more efficient than some enzyme inhibitors used for improving buccal absorption.

Oxidative stress, antioxidants and intestinal calcium absorption

The disequilibrium between the production of reactive oxygen(ROS) and nitrogen(RNS) species and their elimination by protective mechanisms leads to oxidative stress. Mitochondria are the main source of ROS as by-products of electron transport chain. Most of the time the intestine responds adequately against the oxidative stress, but with aging or under conditions that exacerbate the ROS and/or RNS production, the defenses are not enough and contribute to developing intestinal pathologies. The endogenous antioxidant defense system in gut includes glutathione(GSH) and GSH-dependent enzymes as major components. When the ROS and/or RNS production is exacerbated, oxidative stress occurs and the intestinal Ca2+ absorption is inhibited. GSH depleting drugs such as DLbuthionine-S,R-sulfoximine, menadione and sodium deoxycholate inhibit the Ca2+ transport from lumen to blood by alteration in the protein expression and/or activity of molecules involved in the Ca2+ transcellular and paracellular pathways through mechanisms of oxidative stress, apoptosis and/or autophagy. Quercetin, melatonin, lithocholic and ursodeoxycholic acids block the effect of those drugs in experimental animals by their antioxidant, anti-apoptotic and/or anti-autophagic properties. Therefore, they may become drugs of choice for treatment of deteriorated intestinal Ca2+ absorption under oxidant conditions such as aging, diabetes, gut inflammation and other intestinal disorders.

Glutathione depleting drugs, antioxidants and intestinal calcium absorption

Glutathione （GSH） is a tripeptide that constitutes one of the main intracellular reducing compounds. The normal content of GSH in the intestine is essential to optimize the intestinal Ca2＋ absorption. The use of GSH depleting drugs such as DL-buthionine-S,R-sulfoximine, menadione or vitamin K3, sodium deoxycholate or diets enriched in fructose, which induce several features of the metabolic syndrome, produce inhibition of the intestinal Ca2＋ ab-sorption. The GSH depleting drugs switch the redox state towards an oxidant condition provoking oxida-tive/nitrosative stress and inflammation, which lead to apoptosis and/or autophagy of the enterocytes. Either the transcellular Ca transport or the paracellular Ca route are altered by GSH depleting drugs. The gene and/or protein expression of transporters involved in the transcellular Ca2＋ pathway are decreased. The favonoids quercetin and naringin highly abrogate the inhibition of intestinal Ca2＋ absorption, not only by restoration of the GSH levels in the intestine but also by their anti-apoptotic properties. Ursodeoxycholic acid, melatonin and glutamine also block the inhibition of Ca2＋ transport caused by GSH depleting drugs. The use of any of these antioxidants to ameliorate the intestinal Ca2＋ absorption under oxidant conditions associated with different pathologies in humans requires more investigation with regards to the safety,pharmacokinetics and pharmacodynamics of them.

Optimization, characterization and in vitro/vivo evaluation of azilsartan nanocrystals

Azilsartan(AZL), a poorly soluble drug, was considered to be fit for nanocrystals to improve its solubility. Our study intended to prepare AZL nanocrystals by means of bead milling method. Eight stabilizers or their binary combination and the milling time were set to be variable factors to optimize AZL nanosuspension formulation, and six types of freezedrying supports were investigated to reduce the aggregation of particles during the solidification. AZL nanocrystals with or without sodium deoxycholate(NaDC) as combined stabilizer with Poloxamer 188(F68) were prepared owning mean particle sizes of about 300 nm and 460 nm. During the screening processes, the formulation containing NaDC showed a smaller particle size and better stability during lyophilization. The irregular shape and crystal form changing in AZL nanocrystals were discovered by various characterizations. And with physical mixture as reference, nanocrystals showed its improvement about in-vitro dissolution and in-vivo bioavailability. In conclusion, the nanocrystals of AZL could be prepared well in our study. Additionally, our results suggested that NaDC was an appreciated excipient on the nanocrystals platform, which can exhibit the abilities of size-reduction and stabilitymaintaining on freeze-drying.

Novel diet-related mouse model of colon cancer parallels human colon cancer

AIM:To investigate the close parallels between our novel diet-related mouse model of colon cancer and human colon cancer.METHODS:Twenty-two wild-type female mice(ages 6-8 wk)were fed the standard control diet(AIN-93G)and an additional 22 female mice(ages 6-8 wk)were fed the control diet supplemented with 0.2%deoxycho-lic acid[diet+deoxycholic acid(DOC)]for 10 mo.Tu-mors occurred in the colons of mice fed diet+DOC and showed progression to colon cancer[adenocarcinoma(AC)].This progression is through the stages of tubular adenoma(TA),TA with high grade dysplasia or ad-enoma with sessile serrated morphology,intramucosal AC,AC stage T1,and AC stage T2.The mouse tumors were compared to human tumors at the same stages by histopathological analysis.Sections of the small and large intestines of mice and humans were evaluated for glandular architecture,cellular and nuclear morphology including cellular orientation,cellular and nuclear atyp-ia,pleomorphism,mitotic activity,frequency of goblet cells,crypt architecture,ulceration,penetration of crypts through the muscularis mucosa and presence of malignant crypts in the muscularis propria.In addition,preserved colonic tissues from genetically similar male mice,obtained from a prior experiment,were analyzed by immunohistochemistry.The male mice had been fed the control diet or diet+DOC.Four molecular markers were evaluated:8-OH-dG,DNA repair protein ERCC1,autophagy protein beclin-1 and the nuclear location of beta-catenin in the stem cell region of crypts.Also,male mice fed diet+DOC plus 0.007%chlorogenic acid(diet+DOC+CGA)were evaluated for ERCC1,beclin-1 and nuclear location of beta-catenin.RESULTS:Humans with high levels of diet-relatedDOC in their colons are at a substantially increased riskof developing colon cancer.The mice fed diet+DOChad levels of DOC in their colons comparable to that ofhumans on a high fat diet.The 22 mice without addedDOC in their diet had no colonic tumors while 20 ofthe 22 mice(91%)fed diet+DOC developed colonictumors.Furthermore,the tumors in 10 of these mice(45%of mice)included an adenocarcinoma.All micewere free of cancers of the small intestine.Histopatho-logically,the colonic tumor types in the mice werevirtually identical to those in humans.In humans,char-acteristic aberrant changes in molecular markers can be detected both in field defects surrounding cancers(from which cancers arise)and within cancers.In thecolonic tissues of mice fed diet+DOC similar changesin biomarkers appeared to occur.Thus,8-OH-dG wasincreased,DNA repair protein ERCC1 was decreased,autophagy protein beclin-1 was increased and,in thestem cell region at the base of crypts there was sub-stantial nuclear localization of beta-catenin as well asincreased cytoplasmic beta-catenin.However,in micefed diet+DOC+CGA(with reduced frequency ofcancer)and evaluated for ERCC1,beclin-1,and beta-catenin in the stem cell region of crypts,mouse tissueshowed amelioration of the aberrancies,suggestingthat chlorogenic acid is protective at the molecular levelagainst colon cancer.This is the first diet-related modelof colon cancer that closely parallels human progressionto colon cancer,both at the histomorphological level aswell as in its molecular profile.CONCLUSION:The diet-related mouse model of coloncancer parallels progression to colon cancer in humans,and should be uniquely useful in model studies of pre-vention and therapeutics.

Bile salt induced solubilization of methylene blue: Study on methylene blue fluorescence properties and molecular mechanics calculation

Methylene blue(MB) is a hydrophobic drug molecule, having importance both as a staining reagent and pharmaceutical agent. MB is strongly fluorescent, with an emission peak at 686 nm(λ_(ex)665 nm). In the study,the possibility of MB as an extrinsic fluorophore to study the micellization behavior of bile salts(BSs) was carried out. Since BSs are drug delivery systems, the solubilization of hydrophobic MB drug molecule by BSs was achieved and the nature of association of MB with BS media, namely sodium cholate(Na C) and sodium deoxycholate(Na DC) was evaluated. Change in the photophysical properties of MB is monitored through fluorescence intensity and fluorescence anisotropy at emission peak, 686 nm of MB. Molecular mechanics calculations were carried out to evaluate the MB–BS association. The estimated heat of formation, ΔH_f values are –625.19 kcal/mol for MB–Na C and –757.48 kcal/mol for MB–Na DC. The photophysical study also revealed that MB reports the step-wise aggregation pattern of BSs media, as an extrinsic fluorescence probe.

Detection of Pathogenic Bacteria <i>Staphylococcus aureus</i>and <i>Salmonella</i>sp. from Raw Milk Samples of Different Cities of Pakistan

Food-borne diseases are the main public health problem throughout the world. Milk is important component of human diet including fats, proteins, vitamins and minerals. It is a best source of calcium and phosphorus. Different types of pathogenic bacteria like S. aureus and Salmonella enter in milk and then multiply, after multiplication they become active in causing diseases. These bacteria create serious problems for human health. This study aimed to isolate and identify pathogenic bacteria Staphylococcus aureus and Salmonella from raw milk samples of different cities of Pakistan. Primary screening of raw milk samples was done on the basis of morphological, cultural and biochemical techniques. The final identification was made using 16SrRNA sequence analysis. A total of 200 raw milk samples were collected from different cities of Pakistan. Selective medium xylose lysine deoxycholate agar (XLD) and Mannitol salt agar were used for the identification of Salmonella sp. and S. aureus. Staphylococcus aureus produced yellow colonies with yellow zones on Mannitol salt agar. Staphylococcus aureus exhibited gram-positive character with purple coloration and it was detected as cocci-shaped. Biochemically 91 (45%) samples enhibited Catalase, Coagulase, DNase, Urease, Citrate, fermentation tests positive and indole, oxidase and H2S tests negative with nonmotile character, indicating the presence of Staphylococcus aureus. Salmonella sp. was detected as gram negative rods with pink coloration on gram staining. Biochemically 87 (43%) samples revealed catalase, citrate, H2S and fermentation tests positive while oxidase, DNase, Indole and urease tests negative, indicating the presence of Salmonella sp. in these samples. Of the 200 samples tested, 43% were positive for Salmonella, while 45% samples were contaminated with S. aureus. The 16SrRNA sequence analysis confirmed the results of biochemical and cultural characterization by depicting 99% identity of samples with S. aureus and 98% identity with Salmonella spp. The occurrence of high percentage of these pathogenic bacteria in raw milk may be linked to its contamination at the time of collection, processing, strorage and distribution. This quantitative data could be utilized to better establish the appropriate levels of protection for raw milk, dairy products and processing technologies.

Microrheology and Release Behaviors of Self-Assembled Steroid Hydrogels

A hydrogel is formed by the self-assembly of sodium deoxycholate (NaDC) in aqueous solution with sodium chloride at pH-7.0. The NaDC hydrogel made of the three-dimensional network of nanofibers shows pH-dependent swelling behaviors. Polystyrene particles with a diameter of 100 nm and doxorubicin hydrochloride (DOX) can be easily loaded into the NaDC hydrogel through swelling. By using the loaded polystyrene particles as a light scattering probe, we study the microrheology of the NaDC hydrogel, showing complex viscoelastic properties. The viscous component dominates at both low and high frequencies, while the elastic component dominates in the intermediate range. The cavity size of the nanofiber network can also be estimated to be ~180 nm. We show that the loaded DOX can be slowly released from the hydrogels into aqueous solution. The release profile of DOX is found to depend on the pH value of the solution.

A secondary bile acid from microbiota metabolism attenuates ileitis and bile acid reduction in subclinical necrotic enteritis in chickens

Background:Clostridium perfringens-induced chicken necrotic enteritis(NE)is responsible for substantial economic losses worldwide annually.Recently,as a result of antibiotic growth promoter prohibition,the prevalence of NE in chickens has reemerged.This study was aimed to reduce NE through titrating dietary deoxycholic acid(DCA)as an effective antimicrobial alternative.Materials and methods:Day-old broiler chicks were assigned to six groups and fed diets supplemented with 0(basal diet),0.8,1.0 and 1.5 g/kg(on top of basal diet)DCA.The birds were challenged with Eimeria maxima(20,000 oocysts/bird)at d 18 and C.perfringens(109 CFU/bird per day)at d 23,24,and 25 to induce NE.The birds were sacrificed at d 26 when ileal tissue and digesta were collected for analyzing histopathology,mRNA accumulation and C.perfringens colonization by real-time PCR,targeted metabolomics of bile acids,fluorescence in situ hybridization(FISH),or terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL)assay.Results:At the cellular level,birds infected with E.maxima and C.perfringens developed subclinical NE and showed shortening villi,crypt hyperplasia and immune cell infiltration in ileum.Dietary DCA alleviated the NE-induced ileal inflammation in a dose-dependent manner compared to NE control birds.Consistent with the increased histopathological scores,subclinical NE birds suffered body weight gain reduction compared to the uninfected birds,an effect attenuated with increased doses of dietary DCA.At the molecular level,the highest dose of DCA at 1.5 g/kg reduced C.perfringens luminal colonization compared to NE birds using PCR and FISH.Furthermore,the dietary DCA reduced subclinical NE-induced intestinal inflammatory gene expression and cell apoptosis using PCR and TUNEL assays.Upon further examining ileal bile acid pool through targeted metabolomics,subclinical NE reduced the total bile acid level in ileal digesta compared to uninfected birds.Notably,dietary DCA increased total bile acid and DCA levels in a dose-dependent manner compared to NE birds.Conclusion:These results indicate that DCA attenuates NE-induced intestinal inflammation and bile acid reduction and could be an effective antimicrobial alternative against the intestinal disease.

Ursodeoxycholic acid improves gastrointestinal motility defects in gallstone patients

AIM: To simultaneously evaluate the presence of defects in gallbladder and gastric emptying, as well as in intestinal transit in gallstone patients (GS) and the effect of chronic ursodeoxycholic acid (UDCA) administration on these parameters and on serum bile acids and clinical outcome in GS and controls (CTR). METHODS: After a standard liquid test meal, gallbla-dder and gastric emptying (by ultrasound), oroileal transit time (OITT) (by an immunoenzymatic technique) and serum bile acids (by HPLC) were evaluated before and after 3 mo of UDCA (12 mg/kg bw/d) or placebo administration in 10 symptomatic GS and 10 matched healthy CTR. RESULTS: OITT was longer in GS than in CTR (P < 0.0001); UDCA significantly reduced OITT in GS (P < 0.0001), but not in CTR. GS had longer gastric half-emptying time (t1/2) than CTR (P < 0.0044) at baseline; after UDCA, t1/2 significantly decreased (P < 0.006) in GS but not in CTR. Placebo administration had no effect on gastric emptying and intestinal transit in both GS and CTR. CONCLUSION: The gallstone patient has simultaneous multiple impairments of gallbladder and gastric emptying, as well as of intestinal transit. UDCA administration restores these defects in GS, without any effect in CTR. These results confirm the pathogenetic role of gastrointestinal motility in gallstone disease and suggest an additional mechanism of action for UDCA in reducing bile cholesterol supersaturation.

High level of deoxycholic acid in human bile does not promote cholesterol gallstone formation

AIM:To study whether patients with excess deoxycholic acid (DCA) differ from those with normal percentage of DCA with respect to biliary lipid composition and cholesterol saturation of gallbladder bile. METHODS:Bile was collected during operation through puncturing into the gallbladder from 122 cholesterol gallstone patients and 46 gallstone-free subjects undergoing cholecystectomy.Clinical data,biliary lipids,bile add composition, presence of crystals and nucleation time were analyzed. RESULTS:A subgroup of gallstone patients displayed a higher proportion of DCA in bile than gallstone free subjects. By choosing a cut-off level of the 90th percentile,a group of 13 gallstone patients with high DCA levels (mean 50 percent of total bile acids) and a large group of 109 patients with normal DCA levels (mean 21 percent of total bile acids) were obtained.The mean age of the patients with high DCA levels was higher than that of the group with normal levels (mean age:62 years vs45 years) and so was the mean BMI (28.3 vs.24.7).Plasma levels of cholesterol and triglycerides were slightly higher in the DCA excess groups compared with those in the normal DCA group.There was no difference in biliary lipid composition,cholesterol saturation,nucleation time or occurrence of cholesterol crystals in bile between patients with high and normal levels of DCA. CONCLUSION:Gallstone patients with excess DCA were of older age and had higher BMI than patients with normal DCA.The two groups of patients did not differ with respect to biliary lipid composition,cholesterol saturation,nucleation time or occurrence of cholesterol crystals.It is concluded that DCA in bile does not seem to contribute to gallstone formation in cholesterol gallstone patients.

Microwave assisted one-pot synthesis of novel molecular clefts with only one chiral arm based on deoxycholic acid

A rapid, safe, and efficient method for the synthesis of novel molecular clefts based on deoxycholic acid was reported. Seven new molecular clefts have been synthesized in good yields （89-98%）. This method proved to be extremely simple and highly efficient. The structures of these receptors were confirmed by 1H NMR, IR, MS spectra and elemental analysis. 2007 Zhi Gang Zhao. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Design and synthesis of novel tweezer anion receptors based on deoxycholic acid

A novel type of molecular tweezer receptors based on deoxycholic acid has been designed and synthesized and their binding properties were examined by UV-vis spectral titration. These molecular tweezers showed a high selectivity toward F^- over Cl^-, Br^-, I^-, AcO^-, H2PO4^-.

Design and Synthesis of Chiral Molecular Tweezers Based on Deoxycholic Acid

A series of new chiral molecular tweezers have been designed and synthesized by using deoxycholic acid as spacer and aromatic amines as arms. Instead of using toxic phosgene, the triphosgene was employed in synthesis of the molecular tweezers receptors. These chiral molecular tweezers showed good enantioselectivity for D-amino acid methyl esters.

Dietary glycine blunts liver injury after bile duct ligation in rats

AIM： To investigate the effects of （dietary） glycine against oxidant-induced injury caused by bile duct ligation （BDL）.METHODS： Either a diet containing 5% glycine or a standard diet was fed to male Sprague-Dawley （SD） rats. Three days later, BDL or sham-operation was performed. Rats were sacrificed 1 to 3 d after BDL. The influence of deoxycholic acid （DCA） in the presence or absence of glycine on liver cells was determined by measurement of calcium and chloride influx in cultivated Kupffer cells and lactate dehydrogenase （LDH） activity was determined in the supernatant of cultivated hepatocytes.RESULTS： Serum alanine transaminase levels increased to about 600 U/L 1 d alter BDL. However, enzyme release was blunted by about two third in rats receiving glycine. Release of the alkaline phosphatase and aspartate aminotransferase was also blocked significantly in the group fed glycine. Focal necrosis was observed 2 d after BDL. Glycine partially blocked the histopathological changes. Incubation of Kupffer cells with DCA led to increased intracellular calcium that could be blocked by incubation with glycine. However, systemic blockage of Kupffer cells with gadolinium chloride had no effects on transaminase release. Incubation of isolated hepatocytes with DCA led to a significant release of LDH after 4 h. This release was largely blocked when incubation with glycine was performed.CONCLUSION： These data indicate that glycine significantly decreased liver injury, most likely by a direct effect on hepatocytes. Kupffer cells do not appear to play an important role in the pathological changes caused by cholestasis.

Difference and clinical value of metabolites in plasma and feces of patients with alcohol-related liver cirrhosis

BACKGROUND Alterations in plasma and intestinal metabolites contribute to the pathogenesis and progression of alcohol-related liver cirrhosis(ALC).AIM To explore the common and different metabolites in the plasma and feces of patients with ALC and evaluate their clinical implications.METHODS According to the inclusion and exclusion criteria,27 patients with ALC and 24 healthy controls(HCs)were selected,and plasma and feces samples were collected.Liver function,blood routine,and other indicators were detected with automatic biochemical and blood routine analyzers.Liquid chromatography-mass spectrometry was used to detect the plasma and feces metabolites of the two groups and the metabolomics of plasma and feces.Also,the correlation between metabolites and clinical features was analyzed.RESULTS More than 300 common metabolites were identified in the plasma and feces of patients with ALC.Pathway analysis showed that these metabolites are enriched in bile acid and amino acid metabolic pathways.Compared to HCs,patients with ALC had a higher level of glycocholic acid(GCA)and taurocholic acid(TCA)in plasma and a lower level of deoxycholic acid(DCA)in the feces,while L-threonine,L-phenylalanine,and L-tyrosine increased simultaneously in plasma and feces.GCA,TCA,L-methionine,L-phenylalanine,and L-tyrosine in plasma were positively correlated with total bilirubin(TBil),prothrombin time(PT),and maddrey discriminant function score(MDF)and negatively correlated with cholinesterase(CHE)and albumin(ALB).The DCA in feces was negatively correlated with TBil,MDF,and PT and positively correlated with CHE and ALB.Moreover,we established a P/S BA ratio of plasma primary bile acid(GCA and TCA)to fecal secondary bile acid(DCA),which was relevant to TBil,PT,and MDF score.CONCLUSION The enrichment of GCA,TCA,L-phenylalanine,L-tyrosine,and L-methionine in the plasma of patients with ALC and the reduction of DCA in feces were related to the severity of ALC.These metabolites may be used as indicators to evaluate the progression of alcohol-related liver cirrhosis.

Design and synthesis of novel chiral molecular tweezers based on deoxycholic acid

A novel type of chiral molecular tweezers has been designed and synthesized by using deoxycholic acid as backbone and ethanoyl and the chiral unsymmetrical urea unit as arms. Their structures were characterized by 1H NMR, IR, MS spectra and elemental analysis. These molecular tweezers showed good binding ability for neutral molecules and chiral molecules.

Bile acids in serum and bile of patients with cholesterol gallstone

IM To analyze serum bile acids and biliary lipids of patients with cholesterol gallstone(CS) and explore the relationship between deoxycholic acid (DCA) and CS disease.METHODS Analysis of bile acids in serum was done with gaschromatography in two groups: CS group (n=151) and control group (n=256). Serum bile acids and biliary lipids were also studied in 90 matched samples..RESULTS The serum DCA was 0955μmol/L±0078μmol/L in CS group, which was more than that of control group (0696μmol/L±0047μmol/L), P<001. The ratio of DCA/chenodeoxycholic acids (CDCA) was 176±030 in CS group, about two times that in control group (092±014). The mole percent of DCA in bile was positively related to cholesterol saturation index (CSI) (P<001) and the mole percent of CDCA in bile negatively to CSI (P=001). There was correlation between the mole percent of DCA, CDCA and cholic acid in bile and in serum.CONCLUSION It is suggested that DCA is lithogenic and the increased amount of DCA or the ratio of DCA/CDCA in serum may be one of the features of cholesterol gallstone patients.