Fatty acid composition of microsomal phospholipids in rats fed different oils and antioxidant vitamins supplement 11This work was supported by FONDECYT, Proyecto 1960300, and the Universidad de Valparaı́so, Proyecto DIUV 02/95

Individual phospholipid classes from iberian pig meat as affected by diet

The main objectives of this study were to (1) determine the individual phospholipid (PL) classes content of fresh meat from Iberian pigs and their respective fatty acid and dimethylacetal composition and (2) assess the effect of different diets (acorn and grass vs oleic acid enriched concentrates) on these lipid species. First, it was found that phosphatidylcholine was the major PL, followed by phosphatidylethanolamine, phosphatidylserine, and phosphatidylinositol in decreasing order. Each PL class showed a different lipid profile. Second, the feeding regimen influenced the quantity and the fatty composition of the individual PL classes. Meat from pigs fattened with high oleic acid concentrates had higher amounts of most phospholipid classes and polyunsaturated fatty acids, which is an indication of lipid oxidation instability. Lastly, these differences in PL species and fatty acid composition could be used to differentiate meats from Iberian pigs with different feeding regimens.

Stereospecific analysis of phospholipid classes in skeletal muscle from rats fed different fat sources

The fatty acid (FA) and dimethylacetal profiles of the sn-1 and sn-2 positions of different phospholipid (PL) classes from skeletal muscle of rats as affected by dietary FA profiles were studied. Rats were fed either a control diet, an olive oil-enriched diet, or a sunflower oil-enriched diet. The FA composition of both positions of the studied PL classes was affected by diet to different extents. The FA composition of the sn-2 position of phosphatidylserine was the most influenced by diet, while phosphatidylinositol was less affected by dietary modification. The FA profile of phosphatidylcholine reflected consumed FA better than any other studied PL. Thus, olive oil rats showed higher oleic acid (C18:1 n-9) contents in both positions of phosphatidylcholine, and sunflower oil rats had higher proportions of arachidonic acid (C20:4 n-6) in the sn-1 position of this PL class. Dimethylacetals were scarcely affected by diet, and only the dimethylacetal composition of phosphatidylethanolamine showed significant modifications.

Effect of dietary oil intake on hepatic cytochrome P450 activity in the rat

The objective of the present study was to investigate whether or not different dietary oils, commonly used as drug vehicles, alter hepatic microsomal drug metabolism in the rat. Male adult Sprague-Dawley rats were administered 1 mL/kg/d of either corn, olive, sesame, or soybean oil via oral gavage for 7 days. An additional rat group was given an equal volume of water each day to serve as a control. We found that the hepatic cytochrome P450 (CYP) 3A2 protein level increased by 16% (p < 0.01) in rats given soybean oil compared with control rats. In contrast, CYP2C11 protein levels decreased by 32% (p < 0.01) in the corn oil group and by 31% (p < 0. 01) in rats given olive oil. The changes in the in vitro production of 6beta- and 2alpha-hydroxytestosterone, markers of CYP3A2 and 2C11 activities, respectively, were consistent with their protein levels, although not statistically different than controls. The results demonstrate that dietary oils may have differential effects on specific hepatic CYP isoforms and may add to the variability in metabolism when xenobiotics are administered using dietary oils as vehicles.