Phospholipase A2-Mediated preparation of phosphatidylcholine containing ricinoleic acid and its anti-inflammatory effect on murine macrophage-like RAW264.7 cells

Ricinoleic acid (RA) is a type of fatty acid found in castor oil and has been known to have anti-inflammatory effects. Phospholipids are useful functional compounds in food/medical fields due to their amphiphilic property and biocompatibility. The purpose of this study was to prepare phospholipid (PL) containing RA and to evaluate the anti-inflammatory activity of a prepared PL in vitro. Lyso-phosphatidylcholine (LPC) from egg yolk was subjected to phospholipase A(2)-mediated esterification for the preparation of phosphatidylcholine containing RA at sn-2 position (2-RA-PC). The prepared 2-RA-PC was then evaluated for its anti-inflammatory activity against the murine macrophage-like cell line RAW264.7 stimulated by lipopolysaccharide. Using glycerol as solvent and formamide as water mimic, 2-RA-PC was successfully prepared. Upon optimizing the molar ratio (RA/LPC), the amount of glycerol, and the reaction time, a maximum yield of 57.5 mol% was obtained. Analysis of fatty acid compositions of substrate LPC, RA, and synthesized PC suggested almost all RA was incorporated into sn-2 position of LPC. Down regulation of mRNA expression of pro-inflammatory cytokines, interleukin 6 and 1 beta was higher for 2-RA-PC than for RA or Soy-PC, which suggests that the anti-inflammatory effects of RA were improved following phosphatidylation. Our data suggest that 2-RA-PC is a potential lipid for use as an anti-inflammatory compound.