scholarly journals Pancreatic lipase/colipase-mediated triacylglycerol hydrolysis is required for cholesterol transport from lipid emulsions to intestinal cells

1999 ◽  
Vol 339 (3) ◽  
pp. 615-620 ◽  
Author(s):  
Simon C. YOUNG ◽  
David Y. HUI

This study tested the hypothesis that dietary cholesterol uptake by intestinal cells is dependent on the structure and composition of the lipid carriers in the extracellular milieu. In in vivo experiments with female C57BL/6 mice, cholesterol absorption from phospholipid/triacylglycerol emulsions was significantly reduced by administration of tetrahydrolipstatin, an inhibitor of pancreatic lipase. This inhibitor had no effect on the absorption of cholesterol from phospholipid vesicles. The importance of pancreatic-lipase-mediated triacylglycerol hydrolysis for cholesterol transport from emulsions to intestinal cells was confirmed by in vitro experiments with rat IEC-6 intestinal cells. Cellular uptake of cholesterol from emulsions with a phospholipid/triacylglycerol molar ratio of < 0.3 could be stimulated by pancreatic lipase/colipase hydrolysis of the core neutral lipids. However, pancreatic lipase/colipase was ineffective in hydrolysing triacylglycerols in emulsions with a phospholipid/triacylglycerol molar ratio of > 0.3. Phospholipase A2-mediated hydrolysis of the surface phospholipids was necessary prior to triacylglycerol hydrolysis in these phospholipid-rich emulsions and to the stimulation of cholesterol transport from these particles to IEC-6 cells. The data also revealed that minimal triacylglycerol hydrolysis was sufficient to significantly increase cholesterol transport from lipid emulsions to the intestinal cells. Thus the products of triacylglycerol hydrolysis, namely monoacylglycerol and non-esterified fatty acids, are key determinants in mediating cholesterol transport from lipid emulsions to intestinal cells. Taken together, these results support the hypothesis that remodelling of the surface and core components of lipid carriers is necessary prior to absorption of dietary cholesterol from the gastrointestinal tract.

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 119
Author(s):  
Jamal Lasri ◽  
Matti Haukka ◽  
Hessa H. Al-Rasheed ◽  
Nael Abutaha ◽  
Ayman El-Faham ◽  
...  

The square planar complex [Pd(PT)Cl(H2O)]*H2O (HPT: 6-(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazine-2,4(1H,3H)-dione) was obtained by the reaction of 2-methoxy-4,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazine (MBPT) pincer ligand with PdCl2 in a molar ratio (1:1) under thermal conditions and using acetone as a solvent. The reaction proceeded via C-N cleavage of one C-N moiety that connects the pyrazole and s-triazine combined with the hydrolysis of the O-CH3 group. The reaction of the chloride salt of its higher congener (PtCl2) gave [Pt(3,5-dimethyl-1H-pyrazole)2Cl2]. The crystal structure of [Pd(PT)Cl(H2O)]*H2O complex is stabilized by inter- and intra-molecular hydrogen bonding interactions. Hirshfeld analysis revealed that the H...H (34.6%), O...H (23.6%), and Cl...H (7.8%) interactions are the major contacts in the crystal. The charges at Pd, H2O, Cl and PT are changed to 0.4995, 0.2216, −0.4294 and −0.2917 instead of +2, 0, −1 and −1, respectively, using the MPW1PW91 method. [Pd(PT)Cl(H2O)]*H2O complex has almost equal activities against MDA-MB-231 and MCF-7 cell lines with IC50 of 38.3 µg/mL.


2000 ◽  
Vol 6 (6) ◽  
pp. 449-456 ◽  
Author(s):  
F.J. Sánchez-Muniz ◽  
R. Arroyo ◽  
J.M. Sánchez-Montero ◽  
C. Cuesta

Information on digestibility and absorption of oils and fats used for frying is under debate. To get knowledge on this, unused palm olein (9.27 ± 0.10% w/w polar content), used frying palm olein with a moderate degree of alteration (14.81 ± 0.90% w/w polar content) and highly altered used frying palm olein (26.36 ± 0.30% w/w polar content) and their respective nonpolar and polar fractions were studied. Samples were analyzed by high-performance size-exclusion chromatography before and after a 20-min in vitro incubation with pancreatic lipase. Formation of monoacylglycerols and free fatty acids reflected no relevant differences between unused and moderately altered oleins, whereas the most altered olein was hydrolyzed to a much lesser degree. The presence of oligomers (dimers and polymers of triacylglycerols) negatively affected the hydrolysis of triacylglycerol monomers in whole oleins. The hydrolysis of these monomers in the isolated nonpolar and polar fractions ranked between 60.2% and 78.5%. Oligomers were efficiently hydrolyzed by pancreatic lipase in whole un used and moderately altered oleins but not in the most altered one. Polymers from isolated polar fractions were poorly hydrolyzed or not hydrolyzed at all. These data suggest that whole oleins contained some compounds that increase susceptibility of oligomers to enzymatic hydrolysis and that such compounds were not present in the polar fraction.


2007 ◽  
Vol 17 (7) ◽  
pp. 1971-1978 ◽  
Author(s):  
Francesca Cateni ◽  
Paolo Bonivento ◽  
Giuseppe Procida ◽  
Marina Zacchigna ◽  
Giuditta Scialino ◽  
...  

1999 ◽  
Vol 277 (1) ◽  
pp. G120-G126 ◽  
Author(s):  
Vanessa Crespy ◽  
Christine Morand ◽  
Claudine Manach ◽  
Catherine Besson ◽  
Christian Demigne ◽  
...  

Rutin and quercetin absorption and metabolism were investigated in rats after in situ perfusion of jejunum plus ileum (15 nmol/min). In contrast to rutin, a high proportion of quercetin (two-thirds) disappeared during perfusion, reflecting extensive transfer into the intestinal wall. Net quercetin absorption was not complete (2.1 nmol/min), inasmuch as 52% were reexcreted in the lumen as conjugated derivatives (7.7 nmol/min). Enterohepatic recycling contribution of flavonoids was excluded by catheterization of the biliary duct before perfusion. After a 30-min perfusion period, 0.71 μM of quercetin equivalents were detected in plasma, reflecting a significant absorption from the small intestine. The differential hydrolysis of effluent samples by glucuronidase and/or sulfatase indicates that the conjugated forms released in the lumen were 1) glucuronidated derivatives of quercetin and of its methoxylated forms (64%) and 2) sulfated form of quercetin (36%). In vitro quercetin glucuronides synthetized using jejunal and ileal microsomal fractions were similar to those recovered in the effluent of perfusion. These data suggest that glucuronidation and sulfatation take place in intestinal cells, whereas no glucurono-sulfoconjugates could be detected in the effluent. The present work shows that a rapid quercetin absorption in the small intestine is very effective together with its active conjugation in intestinal cells.


2000 ◽  
Vol 130 (5) ◽  
pp. 1108-1114 ◽  
Author(s):  
Jean-Charles Martin ◽  
Jean-Louis Sébédio ◽  
Claude Caselli ◽  
Carole Pimont ◽  
Lucy Martine ◽  
...  

2013 ◽  
Vol 10 (3) ◽  
pp. 954-964
Author(s):  
Baghdad Science Journal

Mefenamic acid was esterified with starchwith[1:1] Molar ratio, as drug substituted with natural polymer, to prolongthe period of hydrolysis of drug polymer with other advantages. The new prodrug starch was characterized by FT-IR and UV-Visible and 1H-NMR spectroscopies. The physical properties were studied and controlled drug release was studied in different pH values at 37oC. The stability of drug was carried out by measuring the absorbance of mefenamic starch which hydrolyzed in HCl solution of pH 1.1 (artificial gastric fluid) and phosphate buffer of pH 7.4 (simulating intestinal fluid SIF) at 37oC for several days. The thermal analysis such as DSC was studied.


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