Effects of oxidation on the hydrolysis by cholesterol esterase of sitosteryl esters as compared to a cholesteryl ester.
Phytosteryl esters (PE) are used as ingredients in functional food to decrease plasma concentration of low density lipoprotein-cholesterol (LDL-C). Effective impairment of cholesterol absorption by PE suggests that these esters are hydrolyzed by the pancreatic cholesterol esterase (CEase, EC 3.1.1.13) and the liberated sterol may interfere with cholesterol reducing its intestinal absorption. PE-enriched foods are marketed for cooking purposes, and temperature is one of the most important factors leading to the formation of oxidation products. Very little is known about the outcome of PE oxides during the digestive process. A new analytical method based on mass spectrometric detection directly after enzymatic reaction was developed to determine in vitro the activity of CEase on PE and their oxides present in functional food. Using this method, we identified a new inhibitor of CEase: sitosteryl 9,10-dihydroxystearate, which behaves as a non-competitive inhibitor of the hydrolysis of cholesteryl oleate and sitosteryl oleate.
Julien-David
Diane
D
IPHC, UMR 7178, Laboratoire de Chimie Analytique et Sciences de l'Aliment-Université de Strasbourg, Faculté de Pharmacie, 74 route de Rhin, 67640 Illkirch-Graffenstaden, France.
Ennahar
Saïd
S
Miesch
Michel
M
Geoffroy
Philippe
P
Raul
Francis
F
Aoude-Werner
Dalal
D
Lessinger
Jean-Marc
JM
Marchioni
Eric
E
D000818:Animals; D002788:Cholesterol Esters / Q000378:metabolism*; D004952:Esters / Q000737:chemistry*; D006868:Hydrolysis / Q000187:drug effects; D000960:Hypolipidemic Agents / Q000737:chemistry* / Q000378:metabolism*; D019301:Oleic Acid / Q000737:chemistry / Q000378:metabolism; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry / Q000378:metabolism; D012855:Sitosterols / Q000737:chemistry* / Q000378:metabolism*; D013228:Stearates / Q000737:chemistry / Q000494:pharmacology; D002787:Sterol Esterase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013552:Swine
D002788:Cholesterol Esters; D004952:Esters; D000960:Hypolipidemic Agents; D010087:Oxides; D012855:Sitosterols; D013228:Stearates; D019301:Oleic Acid; C025473:gamma-sitosterol; D002787:Sterol Esterase