Effects of dietary sea squirt (Halocynthia roretzi) on lipid metabolism in rats

The effect of dietary sea squirt ( Halocynthia roretzi) on lipid metabolism in rats was investigated. Rats were fed sea squirt muscle (Experiment 1); sea squirt muscle, defatted sea squirt muscle and its hexane extract (Experiment 2); and whole body sea squirt and its parts as muscle or viscera (Experiment 3). All of the diets contained the same levels of protein (20%) and lipid (7%). In experiment 1, serum total cholesterol (T-Ch), very-low-density lipoprotein plus low-density lipoprotein (VLDL+LDL)-Ch, triglyceride (TG), phospholipid (PL) and nonesterified fatty acid (NEFA) levels were reduced by 20% dietary sea squirt muscle ingestion; steroid excretions into feces were enhanced by the same diet. In experiment 2, serum T-Ch, (VLDL+LDL)-Ch, TG, PL and NEFA levels were significantly reduced and steroid excretions into feces were significantly enhanced by ingestion of the sea squirt muscle hexane extract. Ingestion of defatted sea squirt muscle also reduced these serum lipid levels, but not as much as did that of whole sea squirt muscle. In experiment 3, serum T-Ch and HDL-Ch levels were significantly elevated by the 10% sea squirt viscera ingestion.