The effect of dietary safflower phospholipid on steroids in gastrointestinal tract of rats fed a hypercholesterolemic diet.

The effect of dietary safflower phospholipid (Saf-PL) on the postprandial changes of steroids in the small intestinal and cecal contents was examined in rats fed a hypercholesterolemic diet. The triglyceride mixture (SP-Oil) containing a comparable amount of linoleic acid to Saf-PL was used as a reference fat source. Saf-PL suppressed the elevation of plasma cholesterol levels at all times after meal intake, when compared to SP-Oil. The reduction of plasma cholesterol in rats fed the Saf-PL diet was exclusively observed both in chylomicron plus very low density lipoprotein (VLDL) and low density lipoprotein (LDL) fractions. The rate of gastric emptying was not modified by the Saf-PL diet. The level of neutral steroids in the small intestinal contents was almost comparable in both groups, but in the cecal contents and feces it was significantly higher in rats fed the Saf-PL diet. On the other hand, the level of acidic steroids in the small intestinal contents tended to be higher in rats fed the Saf-PL diet than in those fed the SP-Oil diet, whereas in the cecal contents and feces it was comparable in the two diets. These results suggest that Saf-PL causes the accumulation of neutral steroids in the cecum due to the rapid transit through the small intestine.