Adipose Tissue Triacylglycerols of Rats Are Modulated Differently by Dietary Isomeric Octadecenoic Acids from Coriander Oil and High Oleic Sunflower Oil

Abstract

Earlier feeding studies of rats revealed that petroselinic acid [18:1(n-12)] from triacylglycerols of coriander (Coriandrum sativum) oil is extensively incorporated into the lipids of heart and liver and metabolized via β-oxidation and chain elongation. We report here the composition and stereospecific distribution of acyl moieties, particularly isomeric octadecenoyl moieties, in adipose tissue triacylglycerols of male weaned Wistar rats fed diets containing, in addition to 20 g corn oil/kg feed, 120 g coriander oil per kg feed at a level of 63 g 18:1(n-12) moieties/100 g acyl moieties of the oil for 10 wk. For comparison, a group of rats was fed a similar corn oil–containing isocaloric diet with large proportions of oleoyl moieties [18:1(n-9)] from high oleic sunflower oil [72 g 18:1(n-9)/100 g acyl moieties of the oil]. The composition of the triacylglycerols of epididymal, subcutaneous and perirenal adipose tissues was very similar for each feeding group, broadly reflecting the composition of the dietary oils. Feeding coriander oil, compared with high oleic sunflower oil, led to extensive incorporation of 18:1(n-12) into the triacylglycerols of the adipose tissues with a concomitant significantly and dramatically lower 18:1(n-9) concentration and, as a consequence, to the generation of triacylglycerol species containing 18:1(n-12) moieties. Petroselinoyl moieties from coriander oil were esterified predominantly at the sn-1,3 positions of the adipose tissue triacylglycerols; 18:1(n-9) moieties from high oleic sunflower oil were fairly evenly distributed between the sn-1,3 and sn-2 positions. We suggest that acyltransferases involved in the biosynthesis of adipose tissue triacylglycerols direct 18:1(n-12) moieties preferentially to sn-1,3-positions.