Isolation and Anti-Fatty Liver Activity of a Novel Cerebroside from the Sea Cucumber Acaudina molpadioides

Cerebrosides are a kind of important bioactive substance in sea cucumber. A novel cerebroside, AMC-2, was purified from the less-polar lipid fraction of the sea cucumber Acaudina molpadioides by repeated column chromatography. The major structure of AMC-2 was analyzed by gas chromatography-mass spectra. The amide-linked fatty acid unit was confirmed to be four saturated and monounsaturated alpha-hydroxy fatty acids, the long-chain base was dihydroxy sphingoid base with one double bond, and the glycosyl group was glucose. We also investigated the anti-fatty liver activity of AMC-2 in rats with fatty liver induced by orotic acid. AMC-2 significantly reduced hepatic triglyceride (TG) and total cholesterol (TC) levels at a diet supplement of 0.03% and 0.006%. The indexes of stearoyl-CoA desaturase (SCD) activity and mRNA expression were significantly decreased by AMC-2. This indicates that AMC-2 ameliorated nonalcoholic fatty liver disease (NAFLD) through suppression of SCD activity and impaired the biosynthesis of monounsaturated fatty acids in the livers of the rats.