Compared with placebo , R10 and R40 significantly decreased the plasma levels of total sphingolipids including those of ceramide ( -33 % and -37 % ) , sphingomyelin ( -27 % and -31 % ) , monohexosylceramide ( -40 % and -47 % ) , dihexosylceramide ( -31 % and -34 % ) , and trihexosylceramide ( -29 % and -31 % ) , and GM3 gangliosides ( -29 % and -26 % ) , lysophosphatidylcholine ( -32 % and -37 % ) , alkylphosphatidylcholine ( -19 % and -19 % ) , phosphatidylcholine ( -17 % and -19 % ) , alkenylphosphatidylcholine ( plasmalogen ) ( -20 % and -22 % ) , alkylphosphatidylethanolamine ( -20 % , P = .008 and -24 % , P = .02 ) , alkenylphosphatidylethanolamine ( plasmalogen ) ( -24 % , P = .003 and -23 % , P = .007 ) , phosphatidylglycerol ( -24 % , P = .07 , -31 % , P = .046 ) , and phosphatidylinositol ( -34 % and -40 % ) .