Phytosterols, besides hypocholesterolemic effect, present anti-inflammatory properties. Little information is available about their efficacy in Inflammatory Bowel Disease (IBD). Therefore, we have evaluated the effect of a mixture of phytosterols on prevention/induction/remission in a murine experimental model of colitis. Phytosterols were administered x os before, during and after colitis induction with Dextran Sodium Sulfate (DSS) in mice. Disease Activity Index (DAI), colon length, histopathology score, 18F-FDG microPET, oxidative stress in the intestinal tissue (ileum and colon) and gallbladder ileum and colon spontaneous and carbachol (CCh) induced motility, plasma lipids and plasma, liver and biliary bile acids (BA) were evaluated. A similar longitudinal study was performed in a DSS colitis control group. Mice treated with DSS developed severe colitis as shown by DAI, colon length, histopathology score, 18F-FDG microPET, oxidative stress. Both spontaneous and induced ileal and colonic motility were severely disturbed. The same was observed with gallbladder. DSS colitis resulted in an increase in plasma cholesterol, and a modification of the BA pattern. Phytosterols feeding did not prevent colitis onset but significantly reduced the severity of the disease and improved clinical and histological remission. It had strong antioxidant effects, almost restored colon, ileal and gallbladder motility. Plasmatic levels of cholesterol were also reduced. DSS induced a modification in the BA pattern consistent with an increase in the intestinal BA deconjugating bacteria, prevented by phytosterols. Phytosterols seem a potential nutraceutical tool for gastrointestinal inflammatory diseases, combining metabolic systematic and local anti-inflammatory effects.

No abstract

No abstract

This study was aimed at investigating the cardiovascular effects of an Olea europea L. leaf extract (OEE), of a Hibiscus sabdariffa L. flower extract (HSE), and of their 13 : 2 w/w mixture in order to assess their cardiac and vascular activity. Both extracts were fully characterized in their bioactive compounds by HPLC-MS/MS analysis. The study was performed using primary vascular endothelial cells (HUVECs) to investigate the antioxidant and cytoprotective effect of the extracts and their mixture and isolated guinea-pig left and right atria and aorta to evaluate the inotropic and chronotropic activities and vasorelaxant properties. In cultured HUVECs, OEE and HSE reduced intracellular reactive oxygen species formation and improved cell viability, following oxidative stress in dose-dependent manner. OEE and HSE exerted negative inotropic and vasorelaxant effects without any chronotropic property. Interestingly, the mixture exerted higher cytoprotective effects and antioxidant activities. Moreover, the mixture exerted an inotropic effect similar to each single extract, while it revealed an intrinsic negative chronotropic activity different from the single extract; its relaxant activity was higher than that of each single extract. In conclusion OEE and HSE mixture has a good potential for pharmaceutical and nutraceutical application, thanks to the synergistic effects of the single phytochemicals.

SUMMARY Bile acid metabolism was investigated in 10 patients after cholecystectomy, 10 gallstone patients, and 10 control subjects. Diurnal variations of serum levels of cholic and chenodeoxycholic acid conjugates were not abolished by cholecystectomy. Cholic acid pool size was significantly reduced in cholecystectomised patients and the fractional turnover rate and the rate of intestinal degradation of bile acid showed a significant increase. In cholecystectomised patients fasting bile was supersaturated in cholesterol, though less than in gallstone patients, but, in both, feeding resulted in improvement of cholesterol solubility in bile. These data suggest that after cholecystectomy the small intestine alone acts as a pump in regulating the dynamics of the enterohepatic circulation of bile acids and that the improvement of cholesterol solubility in bile is due to a more rapid circulation of the bile acid pool in fasting cholecystectomised patients.

No abstract

We report on the relationship between the structure-pharmacokinetics, metabolism, and therapeutic activity of semisynthetic bile acid analogs, including 6a-ethyl-3a,7a-dihydroxy-5b-cholan-24-oic acid (a selective farnesoid X receptor [FXR] receptor agonist), 6a-ethyl-23(S)-methyl-3a,7a,12a-trihydroxy-5b-cholan-24-oic acid (a specific Takeda G protein-coupled receptor 5 [TGR5] receptor agonist), and 6a-ethyl-3a,7a-dihydroxy-24-nor-5b-cholan-23-sulfate (a dual FXR/TGR5 agonist). We measured the main physicochemical properties of these molecules, including ionization constants, water solubility, lipophilicity, detergency, and protein binding. Biliary secretion and metabolism and plasma and hepatic concentrations were evaluated by high-pressure liquid chromatography-electrospray-mass spectrometry/mass spectrometry in bile fistula rat and compared with natural analogs chenodeoxycholic, cholic acid, and taurochenodexycholic acid and intestinal bacteria metabolism was evaluated in terms of 7a-dehydroxylase substrate-specificity in anaerobic human stool culture. The semisynthetic derivatives detergency, measured in terms of their critical micellar concentration, was quite similar to the natural analogs. They were slightly more lipophilic than the corresponding natural analogs, evaluated by their 1-octanol water partition coefficient (log P), because of the ethyl group in 6 position, which makes these molecules very stable toward bacterial 7-dehydroxylation. The hepatic metabolism and biliary secretion were different: 6a-ethyl-3a,7a-dihydroxy-5b-cholan-24-oic acid, as chenodeoxycholic acid, was efficiently conjugated with taurine in the liver and, only in this form, promptly and efficiently secreted in bile. 6a-Ethyl-23(S)-methyl-3a,7a,12a-trihydroxy-5b-cholan-24-oic acid was poorly conjugated with taurine because of the steric hindrance of the methyl at C23(S) position metabolized to the C23(R) isomer and partly conjugated with taurine. Conversely, 6a-ethyl-3a,7a-dihydroxy-24-nor-5b-cholan-23-sulfate was secreted in bile unmodified and as 3-glucuronide. Therefore, minor structural modifications profoundly influence the metabolism and biodistribution in the target organs where these analogs exert therapeutic effects by interacting with FXR and/or TGR5 receptors.

Cholesterol gallstones are dissolved in man by chenodeoxycholic acid (CDCA) and ursodeoxycholic acid (UDCA). To test the comparative efficacy of these two cholelitholytic bile acids, 223 gallstones patients were randomly treated with either UDCA or CDCA at two different doses: 7 to 8 mg per kg per day and 14 to 15 mg per kg per day. Efficacy and factors influencing dissolution (dose, size of the stones, and time) were evaluated after 3, 6, and 12 months of treatment. UDCA was significantly more efficacious than was CDCA after 3 and 6 months of treatment, whereas after 12 months, no significant differences were observed. UDCA was equally effective at high and low doses, both on small and large stones. CDCA was significantly more effective at high doses and on small stones. Seventy-four per cent of the total dissolutions with UDCA and 42% with CDCA occurred within the first 6 months of treatment. Diarrhea and hypertransaminasemia occurred only in the CDCA-treated patients. We conclude that UDCA seems to be the bile acid of choice in dissolving cholesterol gallstones.