DIETARY ERITADENINE-INDUCED ALTERATION OF MOLECULAR-SPECIES COMPOSITION OF PHOSPHOLIPIDS IN RATS

The effect of dietary eritadenine, a hypocholesterolemic compound foun d in the mushroom Lentinus edodes, on the fatty acid and molecular spe cies profiles of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) in the plasma and liver microsomes was investigated in relation to the hypocholesterolemic action of the compound in rats. Animals wer e fed the control or eritadenine-supplemented (50 mg/kg diet) diet for 14 d. Eritadenine supplementation significantly decreased the plasma concentrations of cholesterol and phospholipids, but not triglycerides . The PC/PE ratio of liver microsomes, but not plasma, was also marked ly decreased by eritadenine. Eritadenine supplementation was found to increase the proportion of 18:2n-6 and, inversely, to decrease the pro portion of 20:4n-6 and 22:5n-6 in plasma PC and liver microsomal PC an d PE, indicating that eritadenine depressed the metabolism of linoleic acid. The effect of eritadenine on the profile of n-3 fatty acids was dissimilar in PC and PE. These changes in fatty acid composition were selectively reflected in the molecular species composition of both PC and PE; the extent of increase in 16:0-18:2 molecular species or decr ease in 18:0-20:4 molecular species was apparently greater than that o f other molecular species containing 18:2 or 20:4 in the sn-2 position . These results suggest that, in addition to the decrease in liver mic rosomal PC/PE ratio, the alteration of plasma PC molecular species com position might also participate in the hypocholesterolemic action of e ritadenine.