Hen egg yolk lipid fractions with antiatherogenic properties

Three different types of hen egg yolk, cage‐free, organic and daily fresh, were tested for their antiatherogenic properties. Total lipids ( TL ) of all hen egg yolk samples were extracted by the method of B ligh and D yer and further separated into total polar lipids ( TPL ) and total neutral lipids ( TNL ) by counter current distribution chromatography. TPL and TNL were further separated by preparative thin‐layer chromatography ( TLC ). TL , TPL , TNL and the obtained polar and neutral lipid fractions after TLC separation were tested to determine whether they induce platelet activation or inhibit platelet activating factor ( PAF )‐induced platelet activation. All three hen egg yolk TL samples possessed strong inhibitory activity against PAF ‐induced platelet activation that was mainly attributed to TPL , especially to PL fraction 4. Cage‐free hen egg yolk exhibited the most potent anti‐ PAF activity in all lipid classes ( TL , TPL and TNL ). Thus hen egg yolk contains PAF inhibitors that reinforce their nutritional value in terms of protection against cardiovascular diseases, since PAF is a crucial inflammatory phospholipid mediator that is implicated in the mechanism of atherogenesis.