Total Fecal Bile Acid Research Articles

Effect of Increased Bile Acid Synthesis or Fecal Excretion in Irritable Bowel Syndrome-Diarrhea

Approximately 25% of patients with irritable bowel syndrome-diarrhea (IBS-D) have increased total fecal bile acids (BA) and serum C4 (surrogate for BA synthesis). BA synthesis-related genes (KLB and FGFR4) are associated with colonic transit (CT) in IBS-D. Our aims were: (i) to compare phenotype and pathophysiology in IBS-D patients with increased or normal fecal excretion or synthesis of BA; and (ii) to explore association of variations in two candidate bile-acid synthesis genes (KLB and FGFR4) in these two subgroups of IBS-D. A total of 64 IBS-D patients underwent on one occasion: fasting serum C4 and FGF19, total fecal fat and BA excretion, CT, intestinal and colonic permeability, and candidate genotyping (rs17618244 (KLB), rs351855 (FGFR4)). Colonic sensation and tone were measured in 47 of the IBS-D patients. IBS-D subgroups were identified by fecal BA >2,337 mM per 48 h or by serum C4 >47.1 ng/ml. IBS-D patients with fecal BA >2,337 mM per 48 h (19/54) had significantly greater body mass index, fecal fat, percent chenodeoxycholic acid (CDCA) in feces, and intestinal permeability, and borderline increased CT (P=0.13). Those IBS-D patients with serum C4 >47.1 ng/ml (13/54) had increased total fecal BA excretion and borderline increased colonic permeability. Variants in genes involved in feedback regulation of BA synthesis (KLB, P=0.06 and FGFR4, P=0.09) were potentially associated with the subgroup with elevated serum C4. IBS-D with increased BA excretion or synthesis is associated with significant pathophysiological changes relative to patients with normal BA profile. BA diarrhea is identified more effectively with total fecal BA than with serum C4.

Genetic variation in GPBAR1 predisposes to quantitative changes in colonic transit and bile acid excretion.

The pathobiology of irritable bowel syndrome (IBS) is multifaceted. We aimed to identify candidate genes predisposing to quantitative traits in IBS. In 30 healthy volunteers, 30 IBS-constipation, and 64 IBS-diarrhea patients, we measured bowel symptoms, bile acid (BA) synthesis (serum 7α-hydroxy-4-cholesten-3-one and FGF19), fecal BA and fat, colonic transit (CT by scintigraphy), and intestinal permeability (IP by 2-sugar excretion). We assessed associations of candidate genes controlling BA metabolism (KLB rs17618244 and FGFR4 rs351855), BA receptor (GPBAR1 rs11554825), serotonin (5-HT) reuptake (SLC6A4 through rs4795541 which encodes for the 44-bp insert in 5HTTLPR), or immune activation (TNFSF15 rs4263839) with three primary quantitative traits of interest: colonic transit, BA synthesis, and fecal BA excretion. There were significant associations between fecal BA and CT at 48 h (r = 0.43; P < 0.001) and IP (r = 0.23; P = 0.015). GPBAR1 genotype was associated with CT48 (P = 0.003) and total fecal BA [P = 0.030, false detection rate (FDR) P = 0.033]. Faster CT48 observed with both CC and TT GPBAR1 genotypes was due to significant interaction with G allele of KLB, which increases BA synthesis and excretion. Other univariate associations (P < 0.05, without FDR correction) observed between GPBAR1 and symptom phenotype and gas sensation ratings support the role of GPBAR1 receptor. Associations between SLC6A4 and stool consistency, ease of passage, postprandial colonic tone, and total fecal BA excretion provide data in support of future hypothesis-testing studies. Genetic control of GPBAR1 receptor predisposing to pathobiological mechanisms in IBS provides evidence from humans in support of the importance of GPBAR1 to colonic motor and secretory functions demonstrated in animal studies.

583 GpBAR1 Genotype Predicts Bowel Function and Pathophysiology in Diarrhea-Predominant Irritable Bowel Syndrome

Background: Genetic predisposition in irritable bowel syndrome (IBS) is supported by prior association studies (Camilleri et al AJP 302:G1075-G1084, 2012). To date, no single genetic predisposition has been convincingly associated with symptoms and relevant quantitative traits in IBS. Aim: To identify candidate genes predisposing to symptoms, colonic transit, bile acid disturbances, and epithelial permeability in IBS.Methods:We assessed associations of variations in candidate genes controlling bile acid (BA) metabolism (KLB and FGFR4), BA receptor GPBAR1 (or TGR5), serotonin reuptake (5HTTLPR) or immune activation (TNFSF15) with bowel function, BA synthesis and total fecal BA, colonic transit (CT) and intestinal permeability (IP) in 30 healthy volunteers (HV), 30 patients with IBS-C (constipation) and 64 with IBS-D (diarrhea) (by Rome III criteria). Colonic tone and sensation were also measured by barostat in 48 IBS-D patients. Primary endpoints assessed in all participants were: fasting serum C4 (screen for hepatic BA synthesis rate), total fecal BA and fat excretion (per 48h on 100g fat diet), overall CT by scintigraphy (geometric center, GC) at 24h and 48h, intestinal and colonic permeability by urine mannitol excretion at 0-2h and 8-24h following 2-sugar ingestion test. Candidate genotype analysis of blood DNA was conducted using PCR-based methods: rs4795541 (5HTTLPR); rs351855 (FGFR4); rs17618244 (KLB); rs11554825 (GPBAR1); rs4263839 (TNFSF15). Bowel functions, C4, total and individual fecal BA, CT, colonic sensation, and IP were compared in IBS-C, IBS-D and HV. We used Spearman correlation to explore relationships of total fecal BA with CT and IP. The univariate associations of each genotype were assessed in the total set of participants by the KruskalWallis test (2 degrees of freedom general genetic model). Results: There were expected differences in IBS-C, IBS-D and HV groups in number of BMs, stool consistency and ease of passage, CT (GC48h), IP, fecal fat, serum FGF19 and C4, and total fecal BA (table). There were significant associations between total fecal BA and CT GC48 (r=0.43; p<0.001) and IP (r=0.23; p=0.015). There were significant (p<0.05) univariate associations between: a) GPBAR1 and symptom phenotype, gas sensation ratings, total fecal BA excretion, and CT GC48h. There were weaker associations of GPBAR1 variation with BM frequency and gas sensation threshold (both p<0.1); b) 5HTTLPR and stool consistency and ease of passage, postprandial colonic tone, and total fecal BA excretion; c) FGFR4 and IBS symptom phenotype, postprandial colonic tone, pain sensation threshold and serum FGF19 (p=0.06). Variations in TNFSF15 and KLB were not associated with any traits. Conclusion: Genetic control of 5HT reuptake and GPBAR1 receptor predisposes to symptoms and key pathophysiological mechanisms in IBS. Support: NIH DK92179

A simple and accurate HPLC method for fecal bile acid profile in healthy and cirrhotic subjects: validation by GC-MS and LC-MS

We have developed a simple and accurate HPLC method for measurement of fecal bile acids using phenacyl derivatives of unconjugated bile acids, and applied it to the measurement of fecal bile acids in cirrhotic patients. The HPLC method has the following steps: 1) lyophilization of the stool sample; 2) reconstitution in buffer and enzymatic deconjugation using cholylglycine hydrolase/sulfatase; 3) incubation with 0.1 N NaOH in 50% isopropanol at 60°C to hydrolyze esterified bile acids; 4) extraction of bile acids from particulate material using 0.1 N NaOH; 5) isolation of deconjugated bile acids by solid phase extraction; 6) formation of phenacyl esters by derivatization using phenacyl bromide; and 7) HPLC separation measuring eluted peaks at 254 nm. The method was validated by showing that results obtained by HPLC agreed with those obtained by LC-MS/MS and GC-MS. We then applied the method to measuring total fecal bile acid (concentration) and bile acid profile in samples from 38 patients with cirrhosis (17 early, 21 advanced) and 10 healthy subjects. Bile acid concentrations were significantly lower in patients with advanced cirrhosis, suggesting impaired bile acid synthesis.

Antidyslipidemic effects of a farnesoid X receptor antagonist in primates

AimsWe investigated antidyslipidemic effects of a farnesoid X receptor antagonist compound-T3 in non-human primates as a novel treatment approach for dyslipidemia. Main methodsCynomolgus monkeys were fed a high-fat diet over 3weeks. Drugs were administered to the monkeys for a week, and their plasma and fecal lipid parameters were measured. Key findingsCompound-T3 dose-dependently decreased the plasma non-high-density lipoprotein (non-HDL) cholesterol and apolipoprotein B levels in high-fat diet-fed cynomolgus monkeys. The plasma levels of 7α-hydroxy-4-cholesten-3-one, a marker of hepatic cholesterol 7α-hydroxylase activity, and total fecal bile acid levels increased, suggesting that the hypocholesterolemic effects would be dependent on the activation of cholesterol catabolism in the liver. Compound-T3 significantly increased the plasma levels of HDL cholesterol and apolipoprotein A-I. In this condition, the cholesterol absorption inhibitor ezetimibe significantly decreased the plasma non-HDL cholesterol levels and increased the fecal cholesterol levels without affecting plasma HDL cholesterol and triglyceride levels. Bile acid sequestrant cholestyramine tended to decrease plasma non-HDL cholesterol and increase fecal bile acid levels. The cholesteryl ester transfer protein inhibitor torcetrapib significantly increased plasma HDL cholesterol levels without affecting plasma non-HDL cholesterol and fecal cholesterol levels. SignificanceThe results of ezetimibe, cholestyramine, and torcetrapib treatments indicate that our high-fat diet fed monkey model would be a preferred animal model for studying non-statin type antidyslipidemic drugs. Compound-T3 significantly decreased non-HDL cholesterol levels and increased HDL cholesterol levels in the monkey model, suggesting that a farnesoid X receptor antagonist could be a therapeutic option in human dyslipidemia.

Depicting a novel regulatory Bcl2/SHP/lncRNA H19 network in bile acid homeostasis (605.12)

Objective: The aim of this study is to investigate a novel function of the anti‐apoptotic protein Bcl2 in bile acid (BA) homeostasis. Methods: Bcl2 was overexpressed using adenoviruses in male C57BL6 livers. After two weeks, BA homeostasis, liver morphology, fibrosis, and inflammation were analyzed. RNA‐seq and GC/MS were used to identify changes in gene expression and metabolites, respectively. Results: Hepatic overexpression of Bcl2 largely induced serum BA and FGF15 levels and decreased total BA pool size and fecal BA output. Severe hepatocyte necrosis, fibrosis, and Kupffer cell activation were observed, which was accompanied by a marked induction of long non‐coding RNA H19. RNA‐seq identified significant downregulation of genes in bile acid synthesis and transport, but upregulation of genes in collagen formation and inflammatory response by Bcl2. The increases in TCA cycle and lipid metabolites were the most drastic metabolomics changes. Using a series of cell based biochemistry and molecular biology approaches, we found that Bcl2 induced rapid nuclear receptor SHP protein degradation via activation of the caspase 8‐caspase 3 pathway. Furthermore, bile acid directly induced H19 expression in cultured primary hepatocytes that was independent of Bcl2 activation by bile acid. Importantly, Bcl2 and H19 were both dramatically increased in human cirrhotic livers and in mouse cholestatic liver fibrosis models. The dysregulation of the Bcl2/SHP/H19 network resulted in the disruption of bile acid homeostasis which contributed to the development of cholestatic liver fibrosis. Conclusions: Our results uncovered a unique metabolic regulatory network that integrated Bcl2 and SHP with lncRNA H19 to control BA homeostasis.Grant Funding Source: Supported by DK080440 (L.W).

Bile acid and sterol metabolism with combined HMG-CoA reductase and PCSK9 suppression

Proprotein convertase subtilisin-kexin-9 (PCSK9) inhibition markedly augments the LDL lowering action of statins. The combination is being evaluated for long-term effects on atherosclerotic disease outcomes. However, effects of combined treatment on hepatic cholesterol and bile acid metabolism have not yet been reported. To study this, PCSK9-Y119X mutant (knockout) and wild-type mice were treated with or without atorvastatin for 12 weeks. Atorvastatin progressively lowered plasma LDL in each group, but no differences in liver cholesterol, cholesterol ester, or total bile acid concentrations, or in plasma total bile acid levels were seen. In contrast, atorvastatin increased fecal total bile acids (≈ 2-fold, P < 0.01) and cholesterol concentrations (≈ 3-fold, P < 0.01) versus controls for both PCSK9-Y119X and wild-type mice. All 14 individual bile acids resolved by LC-MS, including primary, secondary, and conjugated species, reflected similar increases. Expression of key liver bile acid synthesis genes CYP7A1 and CYP8B1 were ≈ 2.5-fold higher with atorvastatin in both strains, but mRNA for liver bile acid export and reuptake transporters and conjugating enzymes were not unaffected. The data suggest that hepatocyte cholesterol and bile acid homeostasis is maintained with combined PCSK9 and HMG-CoA reductase inhibition through efficient liver enzymatic conversion of LDL-derived cholesterol into bile acids and excretion of both, with undisturbed enterohepatic recycling.

The hypocholesterolemic activity of Momordica charantia fruit is mediated by the altered cholesterol- and bile acid–regulating gene expression in rat liver

Although many studies have demonstrated the hypocholesterolemic activity of Momordica charantia, also called bitter gourd fruit (BGF), the relative hypocholesterolemic mechanism is not fully understood. In the present study, we hypothesized that BGF alters hepatic gene expression of cholesterol- and bile acid–regulating proteins to improve blood cholesterol profiles. To clarify the mechanism, we fed 7-week-old male Wistar rats a high-cholesterol (HC) diet containing 5% BGF for 4 weeks and determined the cholesterol levels in the serum, liver and feces, concentrations of the fecal total bile acid, and the expression level of cholesterol- and bile acid–regulating genes. The HC diet with BGF supplementation showed a significant serum hypocholesterolemic activity compared with the HC diet without BGF. BGF intake also significantly increased the levels of fecal total bile acid, suggesting that BGF inhibited the reabsorption of bile acids into the intestine. Hepatic messenger RNA (mRNA) levels of small heterodimer partner (SHP) and liver receptor homolog-1, which are both involved in cholesterol 7α-hydroxylase (CYP7A1) regulation, were significantly decreased and increased, respectively, by BGF intake. In addition, BGF tended to increase the hepatic CYP7A1 mRNA level. Taken together, these results suggest that BGF not only decreases the reabsorption of bile acids into the intestine but also increases the conversion of cholesterol to bile acids by CYP7A1 up-regulation through the down-regulation of the hepatic farnesoid X receptor/SHP pathway.

Tu2057 Assessment of Bowel Symptoms, Colonic Transit, and the Relationship to Fecal Bile Acid (BA) Excretion in Health and Irritable Bowel Syndrome (IBS)

Background: Idiopathic bile acid malabsorption (BAM) causes chronic diarrhea and BA deficiency may cause constipation. BA supplementation and an ileal BA transporter inhibitor, elobixibat, accelerate colonic transit (CT). Rectal infusion of BA (e.g. chenodeoxycholate) induces colonic propulsive motility. Up to 50% of patients with IBS-D have accelerated CT; 20% of patients with IBS-C have delayed CT. The relationship between fecal BA excretion, CT, and bowel symptoms in IBS is unclear and may be relevant to selecting optimal therapy. Aim: To assess stool frequency (number) and consistency (form) in relation to CT and fecal BA excretion in healthy participants and patients with IBS-C and IBS-D. Methods: In a prospective study of 92 participants (31 healthy, 30 IBS-C and 31 IBS-D by Rome III criteria), we measured total and individual fecal BA and fecal fat (on 100g fat diet), overall CT by validated scintigraphy (geometric center, GC at 24 and 48h) and stool characteristics by a 14 day bowel pattern diary including Bristol stool form scale. Univariate associations between endpoints were assessed using Spearman correlation (rs). Relationships between stool characteristics, CT and fecal BA excretion were assessed using response surface multiple regression models (which included BMI as a covariate and linear, quadratic and cross product terms for the CT and BA measurements). Results: 1. There were significant univariate associations (table showing rs) between stool number and stool form and total fecal BA (including % LCA, % CDCA, and % CA), fecal fat, and GC24 and 48. 2. The response surface model for stool number (figure left panel) with total fecal BA and CT (GC24 ) explained 29% of the variation (r=0.54, p,0.001); similarly, the model for stool form (figure middle panel) with fecal BA and CT (GC24) explained 20% of the variation (r=0.45, p=0.021). Using total secretory BA (CA+DCA+CDCA), the response surface model for stool form (figure right panel) explained 23% of the variation (r=0.49, p=0.006). In these models, the relative contribution of CT was consistently greater than that for BA, with the coefficients corresponding to CT being statistically significant (p,0.05), while those for BA were borderline (e.g. p=0.073 for the coefficient for secretory BA and stool form, and p=0.227 for stool number). Conclusion: Relative to fecal BA, colonic transit is the greater determinant of stool number and stool form; increased total and secretory fecal BA enhance the effects of colon transit on stool characteristics, but are not independently significant factors. Funding:NIHDK92179

Hypocholesterolemic effect of capsaicinoids by increased bile acids excretion in ovariectomized rats

This study investigated the interaction of dietary capsaicinoids with the mRNA and protein expressions of key receptors and enzymes involved in cholesterol metabolism in ovariectomized (OVX) rats. Female Sprague-Dawley rats were subjected to sham operation or ovariectomy. The sham group and OVX control group were fed with high-cholesterol diets, whereas the treatment group (control diet containing 0.01% capsaicinoids) was fed with high-cholesterol plus 0.01% capsaicinoids diet for 21 days. Capsaicinoids significantly decreased the body weight gain, plasma total cholesterol, LDL cholesterol, and triacylglycerol without affecting the high-density lipoprotein cholesterol in the OVX rats. The change in plasma lipoprotein profile was accompanied by a greater excretion of total bile acid in feces and small intestinal contents. Western blot and real-time PCR analyses revealed that capsaicinoids significantly enhanced the expressions of hepatic cholesterol 7α-hydroxylase and transient receptor potential vanilloid type-1 but did not affect the expression of 3-hydroxy-3-methylglutaryl-CoA reductase in the OVX rats. Capsaicinoids have cholesterol-lowering effects in OVX rats. The hypocholesterolemic activity of capsaicinoids is caused by the stimulating conversion of cholesterol to bile acids by upregulation of cholesterol 7α-hydroxylase expression and the increase in fecal total bile acid excretion.

Role of plant stanol derivatives in the modulation of cholesterol metabolism and liver gene expression in mice

The present study was to evaluate the cholesterol-lowering effect of two novel plant stanol derivatives and its potential molecular mechanism in hyper-cholesterol mice induced by a high-cholesterol diet. Results showed that oral administration of plant stanyl hemisuccinate (2×, 5×) and plant stanyl sorbitol succinate (2×, 5×) effectively attenuated the serum total cholesterol and low density lipoprotein cholesterol levels, while had no effect on the serum triacylglycerol and high density lipoprotein cholesterol. And plant stanol derivatives decreased liver cholesterol concentration and increased faecal cholesterol output. Meanwhile, both plant stanyl hemisuccinate and plant stanyl sorbitol succinate could remarkably promote liver X receptor alpha (LXRα) expression, and increased cholesterol 7α-hydroxylase (CYP7A1) expression and faecal total bile acid output to varying degrees. These results suggested two novel plant stanol derivatives possessed hypocholesterolemic effect, and the cholesterol-lowering action of plant stanol derivatives may be through activating the potential LXRα-CYP7A1-bile acid excretion pathway.

Soy protein isoflavones differentially regulate liver X receptor isoforms to modulate lipid metabolism and cholesterol transport in the liver and intestine in mice

Liver X receptor (LXR)α regulates the genes involved in cholesterol, fatty acid and glucose metabolism. Soy protein (SP) consumption reduces the hepatic accumulation of cholesterol and triacylglycerol, and improves insulin sensitivity. However, it is not known whether these effects are mediated via LXRα. We therefore investigated whether the consumption of SP regulates metabolic changes in cholesterol metabolism and insulin sensitivity via LXRα. Wild-type (WT) and Lxrα(-/-) (Lxrα, also known as Nr1h3) mice were fed an SP diet with or without cholesterol for 28 days. The expression of LXRα target genes was measured in liver and intestine, as were hepatic lipid content and faecal bile acid concentration. Oral glucose and insulin tolerance tests were also performed. Hepatocytes were used to study the effect of isoflavones on LXR activity. The livers of WT and Lxrα(-/-) mice fed an SP high-cholesterol diet showed less steatosis than those fed casein. The SP diet increased the expression of the ATP-binding cassette (ABC) sub-family genes Abca1, Abcg5 and Abcg8 in the liver and intestine, as well as increasing total faecal bile acid excretion and insulin sensitivity in WT mice compared with mice fed a casein diet. However, these effects of SP were not observed in Lxrα(-/-) mice. The SP isoflavone, genistein, repressed the activation of LXRα target genes by T0901317, whereas it stimulated the activation of LXRβ target genes. The AMP-activated protein kinase inhibitor, compound C, had the opposite effects to those of genistein. Our results suggest that SP isoflavones stimulate the phosphorylation of LXRα or LXRβ, resulting in different biological effects for each LXR isoform.

Selection of potential probiotic lactobacilli for cholesterol-lowering properties and their effect on cholesterol metabolism in rats fed a high-lipid diet

The objectives of this study were to screen probiotic characteristics of lactobacilli isolated from traditionally homemade koumiss products in Xinjiang and Inner Mongolia of China, and to determine and compare the effect of the Lactobacillus strains in vivo on lipid metabolism in rats fed with a high-lipid diet. Three out of 68 strains of Lactobacillus isolated from the koumiss were screened for bile-salt resistance, acid tolerance, and different hypocholesterolemic properties. The cholesterol-lowering effects of the 3 screened strains were estimated in rats fed a high-lipid diet by determination of serum lipids, liver, and fecal cholesterol, fecal total bile acids, and short-chain fatty acids. After a 4-wk feeding period, in comparison with the control group, the groups LIP-1 and MG9-2 had a significant reduction in serum total cholesterol, triglyceride and low-density lipoprotein cholesterol, and significantly increased high-density lipoprotein, the group E7301 had similar effects on serum lipids, but the change was not significant. The groups LIP-1, MG9-2 and E7301 had a significant reduction in liver cholesterol content and an increase in fecal cholesterol content compared with the control group. Total bile acid excretion was significantly higher in rats fed MG9-2 than the other groups. Rats fed diets containing lactic acid bacteria strains had significantly higher propionic acid and butyric acid concentrations in the feces compared with the control. Results indicated that the 3 screened Lactobacillus strains were able to lower cholesterol in vitro, and reduce cholesterol effectively in vivo. The mechanisms behind the hypocholesterolemic effect of 3 strains are likely to be diverse and will need further investigation.

CETP Inhibitor Torcetrapib Promotes Reverse Cholesterol Transport in Obese Insulin‐Resistant CETP‐ApoB100 Transgenic Mice

Insulin resistance and type 2 diabetes are associated with low HDL-cholesterol (HDL-c) levels, which would impair reverse cholesterol transport (RCT). A promising therapeutic strategy is to raise HDL with cholesteryl ester transfer protein (CETP) inhibitors, but their effects on RCT remains to be demonstrated in vivo. We therefore evaluated the effects of CETP inhibitor torcetrapib in CETP-apolipoprotein (apo)B100 mice made obese and insulin resistant with a 60% high-fat diet. High-fat diet over 3 months increased body weight and homeostasis model of insulin resistance index by 30% and 846%, respectively (p < 0.01 for both vs. chow-fed mice). Total cholesterol (TC) increased by 46% and HDL-c/TC ratio decreased by 28% (both p < 0.05). Compared to vehicle, high-fat-fed mice treated with torcetrapib (30 mg/kg/day, 3 weeks) showed increased HDL-c levels and HDL-c/TC ratio by 41% and 37% (both p < 0.05). Torcetrapib increased in vitro macrophage cholesterol efflux by 22% and in vivo RCT through a 118% increase in (3) H-bile acids fecal excretion after (3) H-cholesterol labeled macrophage injection (p < 0.01 for both). Fecal total bile acids mass was also increased by 158% (p < 0.001). In conclusion, CETP inhibition by torcetrapib improves RCT in CETP-apoB100 mice. These results emphasize the potential of CETP inhibition to prevent cardiovascular diseases.

Effects of dietary cholesterol on growth performance, feed intake and cholesterol metabolism in juvenile turbot ( Scophthalmus maximus L.) fed high plant protein diets

A 9-week growth trial was conducted to investigate the effects of dietary cholesterol supplementation on growth performance, feed intake and cholesterol metabolism of juvenile turbot ( Scophthalmus maximus L.) fed high plant protein diets. A fish meal diet (diet FM) with 58% FM was formulated, and this diet was used as control. The other four diets were formulated to contain 14.5% FM, 42.0% soybean meal (SBM), and 18.5% wheat gluten meal. The four diets were supplemented with 0.0%, 0.5%, 1.0% and 1.5% cholesterol, respectively, and were isonitrogenous and isolipidic to the diet FM. They were named as diet C-0.0%, C-0.5%, C-1.0% and C-1.5%, respectively. The final dietary cholesterol concentrations were 0.30%, 0.77%, 1.25%, and 1.78%, respectively. That in control diet was 0.63%. The results showed that weight gain rate (WGR) and feed efficiency rate in fish fed diet FM were significantly higher than those in fish fed other diets ( P < 0.05). Furthermore, compared with fish fed diet C-0.0%, fish fed diet C-1.0% significantly enhanced WGR, feed intake (FI) and cholesterol levels in plasma and liver. However, WGR and FI in fish fed diet C-1.5% were significantly lower than those in fish fed diet C-1.0% ( P < 0.05). Fish fed diet C-1.0% showed significantly higher whole-body lipid content than that of fish fed other diets ( P < 0.05). The total cholesterol (TC), free cholesterol (FC), cholesterol esters, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) contents in fish plasma, TC and cholesterol esters in fish liver, and TC in fish feces were significantly correlated with dietary cholesterol contents, and correlated coefficients were above 0.74. Fish fed diet C-0.0% showed the lowest fecal total bile acid and activity of cholesterol 7α hydroxylase among dietary treatments. These results suggested that 1.25% of dietary cholesterol is helpful for juvenile turbot fed high plant protein diets to get significantly better growth rate without negative effects.

Effects of Konjac Glucomannan on Putative Risk Factors for Colon Carcinogenesis in Rats Fed a High-Fat Diet

The aim of this study was to determine effects of konjac glucomannan (KGM) in a high fat corn oil diet on risk factors of colon carcinogenesis, that is, fecal β-glucuronidase, mucinase, and bile acids, and on preventive factors, that is, fecal microflora and cecal short-chain fatty acids (SCFAs). Sprague-Dawley rats (n = 8 animals per group) were fed a normal-fat fiber-free (5% corn oil, w/w) or high-fat (25% corn oil, w/w) diet containing no fiber, KGM (5%, w/w), or inulin (5%, w/w, as a prebiotic control) for 4 weeks. Results indicated that the high-fat fiber-free diet significantly elevated the fecal β-glucuronidase and mucinase activities and total bile acid concentration and decreased cecal SCFA contents, as compared with its normal-fat counterpart. The incorporation of KGM, as well as inulin, into the high-fat fiber-free diet beneficially reduced the fecal β-glucuronidase and mucinase activities and lithocholic acid (secondary bile acid) concentration. Although KGM elevated the daily fecal total bile acid excretion, the change was due to the primary, instead of the secondary, bile acids. In addition, KGM beneficially promoted the daily fecal excretion of bifidobacteria and lactobacilli and cecal SCFA contents, as compared with the high-fat fiber-free diet. Therefore, the present study suggests that KGM potentially attenuated the high fat-induced risk in colon carcinogenesis.

Clerodendron glandulosum Coleb., Verbenaceae, ameliorates high fat diet-induced alteration in lipid and cholesterol metabolism in rats

The present study was undertaken to evaluate the efficacy of freeze dried extract of Clerodendron glandulosum Coleb., Verbenaceae, leaves (FECG) on alteration in lipid and cholesterol metabolism in high fat diet fed hyperlipidemic rats. Plasma and hepatic lipid profiles, lipid and cholesterol metabolizing enzymes in target tissues and fecal total lipids and bile acid contents were evaluated in FECG treated normolipidemic and hyperlipidemic rats. These results were compared with synthetic hypolipidemic drug Lovastatin (LVS). Results indicate that FECG was able to positively regulate induced experimental hyperlipidemia by significant alteration in plasma and tissue lipid profiles. These results can be attributed to reduced absorption, effective elimination and augmented catabolism of lipids and cholesterol possibly due to high content of saponin and phytosterols in C. glandulosum. Use of C. glandulosum extract as a potential therapeutic agent against hypercholesterolemia and hypertriglyceridemia is indicated.

Dysregulation of Lipid and Cholesterol Metabolism in High Fat Diet Fed Hyperlipidemic Rats: Protective Effect of Sida rhomboidea. roxb Leaf Extract

The present study was undertaken to evaluate the efficacy of freeze dried extract of Sida rhomboidea. roxb leaves (FESR) on alteration in lipid and cholesterol metabolism in high fat diet induced hyperlipidemia in experimental rats. Plasma and hepatic lipid profiles, lipid and cholesterol metabolizing enzymes in target tissues and fecal total lipids and bile acid contents were evaluated in FESR treated normolipidemic and hyperlipidemic rats. These results were compared with synthetic hypolipidemic drug lovastatin (LVS). Results indicate that FESR was able to positively regulate induced experimental hyperlipidemia by significant alteration in plasma and tissue lipid profiles. These results can be attributed to reduced absorption, effective elimination and augmented catabolism of lipids and cholesterol possibly due to high content of saponin and phytosterols in S. Rhomboidea. roxb (SR). Use of SR extract as a potential therapeutic agent against hyperlipidemia is indicated.

매생이 추출물이 흰주의 간장조직과 분변 중의 콜레스테롤 함량에 미치는 영향

We investigated the effect of a green seaweed Capsosiphon fulvescens extract (CFE) on the serum, liver tissue, and fecal cholesterol levels in rats. Male Sprague-Dawley rats (four weeks old) were given on of three diets for four weeks: basal, high cholesterol, and CFE, The total serum and liver tissue cholesterol levels in the CFE group were significantly decreased compared to those in the cholesterol group. The CFE group showed increased amounts of feces, total fecal bile acid and dietary fiber as compared to basal and cholesterol group. Hematoxylin and eosin staining revealed fat droplets in the livers of the rats in the cholesterol group; however, a decreased number of droplets was observed in the rats fed the CFE diet. Our results suggest that CFE supplementation may improve lipid metabolism, by controling serum and liver tissue cholesterol levels, and by increasing the total amounts of bile acid, dietary fiber and cholesterol excretion in feces.

Investigation on the Lipid- and Cholesterol-Lowering Abilities of Biocellulose

The present study investigated and compared the physicochemical properties as well as the hypolipidemic and hypocholesterolemic effects between plant cellulose and biocellulose. Biocellulose had higher water-holding and cation-exchange capacities than plant cellulose ( approximately 2- and 6-fold, respectively). The results showed that the administration of plant cellulose and biocellulose to hamsters effectively ( P < 0.05) decreased the concentrations of serum triglyceride (by 13.9-55.5%), serum total cholesterol (by 17.4-27.9%), serum low-density lipoprotein cholesterol (by 41.9-47.9%), liver total lipids (by 6.4-10.3%), and liver cholesterol (by 11.8-16.3%). Feeding plant cellulose and biocellulose also enhanced the excretion of total lipids (144-182%), cholesterol (136-203%), and bile acids (259-479%) in feces. The efficacy of biocellulose in lowering serum lipids and cholesterol in hamsters was significantly higher than that of plant cellulose. These results suggested that biocellulose could be a promising low-calorie bulking ingredient for the development of novel fiber-rich functional foods of different forms such as powder, gelatinous, or shred forms.