米由来スフィンゴ糖脂質の新規機能性とその応用

摘要

Glycosphingolipids such as ceramide and glucosylceramide widely distribute in animals,plants,and microorganisms.These compounds are known to regulate skin moisture and protect internal tissue from external damage.Our group highly purified glucosylceramide from rice bran and identified the structure,a glucose coupled with 4,8-sphingadiene and 2-hydroxy arachidic acid.As an evaluation of skin whitening and protective effects of rice-derived glycosphingolipids,rice germ-derived glycosphingolipid(purity:95%)and its acid hydrolysate inhibited tyrosinase activity and melanin formation in mice melan-a cells in a range of 5 to 20 mu g/ml.Moisture-retaining effects of commercial products containing 3% glycosphingolipids derived from rice germ,devil's-tongue and wheat were compared in test tubes,and rice germ-derived glycosphingolipid showed highest moisture retaining effect.More over,purified glycosphingolipid(1 mu g/ml,purity:>95%)from rice germ inhibited antigen-induced degranulation in sensitized RBL-2H3 mast cells.Continuous ingestion of the diet containing the glycosphingolipid(0.15 to 0.5%)reduced number of scratching behavior in mice itching model induced by compound 48/80.On the other hand,continuous(8 weeks)ingestion of the diet containing glycosphingolipid(100 and 250 ppm,purity:>90%)reduced the number of aberant crypt foci and mucin depleted foci in colon cancer rat induced by azoxymethane.We followed these new findings and developed high concentration of glycosphingolipid powder(8 to 20%)and liquid(0.8 to3%).These products are applicable to functional foods and cosmetics for beauty and prevention of cancer.