Lysophospholipids have been recognized as potent biologically active lipid mediators. However, attention has not been paid to the health benefits of dietary partial hydrolysate of phospholipids (PH‐PL), which is rich in docosahexaenoic acid (DHA)‐bound lysophospholipids. In this study, the effects of PH‐PL on serum and liver lipid profiles of rats upon administration of PH‐PL are demonstrated in comparison to those of fish oil (FO), which comprises eicosapentaenoic acid (EPA) and DHA‐bound triglyceride (TG). PH‐PL containing EPA and DHA was prepared via enzymatic modification of squid (Todarodes pacificus) meal that is rich in phospholipids. Male Wistar rats were fed a basal diet containing soybean oil alone (7%), FO, and PH‐PL. The FO and PH‐PL diets had similar EPA and DHA contents. After the rats had been fed their respective diets for 28 d, their serum and liver lipid contents, fecal lipid excretion, and hepatic gene expression level were measured. The results demonstrated that compared with the soybean oil diet alone, the PH‐PL diet decreased serum and liver TG contents partially because of the enhancement of liver acyl‐CoA oxidase activity and suppression of liver fatty acid synthase activity. In addition, compared with the soybean oil diet, the PH‐PL group exhibited lower serum cholesterol content at least in part because of the reduction of hepatic 3‐hydroxy‐3‐methylglutaryl‐CoA reductase mRNA expression level. We found that dietary administration of EPA and DHA containing PH‐PL has a hypolipidemic effect that may help prevent the development lifestyle‐related diseases.

Internal organs of discarded scallops are rich in omega-3 polyunsaturated fatty acids, but it is not used as a food ingredient due to the presence of toxic substances. Recently, our research team prepared high-quality scallop oil (SCO) from the internal organs of the Japanese giant scallop (Patinopecten yessoensis), in which cadmium and diarrhetic shellfish toxin are below regulated levels. In this study, SCO was prepared from the internal organs of scallops obtained from Mutsu and Uchiura bays in Japan, and was referred to as SCO-M (scallop oil from Mutsu bay) and SCO-U (scallop oil from Uchiura bay), respectively. Acute and subacute toxicity studies were performed to assess the safety of the prepared SCO. In acute toxicity study, mice were orally administered SCO-M and SCO-U at a single dose of 5,000 mg/kg body weight. In a 28-day repeated oral dose toxicity study, the mice were fed diets containing 1% and 5% SCO-M and SCO-U; and in a 13-week repeated oral dose toxicity study, the mice were fed 5% SCO-M and SCO-U. There were no toxicologically significant changes in clinical signs, hematology, blood chemistry, and organ weights at any dose during the experiment. Therefore, it was concluded that SCO-M and SCO-U are safe for use as food ingredients under the experimental conditions of this study.

IntroductionFish oil is rich in n-3 polyunsaturated fatty acids PUFA , such as eicosapentaenoic acid EPA and docosahexaenoic acid DHA . The intake of EPA and DHA has beneficial effects on human health, including anti-arrhythmic 1 , antiinflammatory 2 , and anti-hypertriglyceridemic 3 effects. In addition to EPA and DHA, fish oil is composed of uncommon n-3 PUFA such as 6,9,12,15-octadecatetraenoic acid C18:4n-3 and 4,7,10,13-hexadecatetraenoic acid C16:4n-3 4 , which are physiologically relevant. Previous studies reported that C18:4n-3 has inhibitory effects on platelet aggregation 5 and the metabolism of C18:4n-3 in cultured NIH-3T3 cells 6 , while C16:4n-3 and C18:4n-3 have been reported to inhibit the production of leukotriene B4, leukotriene C4, and 5-hydroxyeicosatetraenoic acid in mouse mast cells 7 . A trace amount of C16:4n-3 induced by platinum-based chemotherapy was resistant to antitumor activity in mice, and fish oil containing C16:4n-3 neutralized the antitumor activity of platinum-based chemotherapy in various mouse models 8 . Fish oils derived from sardine and herring contain approximately 1 to 3 of 6,9,12, 15-hexadecatetraenoic acid C16:4n-1, HDTA , an isomer of C16:4n-3 4 . HDTA is uniquely characterized by the pres-

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