Lutein is a competitive inhibitor of cytosolic Ca2+-dependent phospholipase A(2)

초록

Objectives We have investigated the effect of lutein on phospholipase A(2) (PLA(2)) isozymes. Methods We measured arachidonic acid release in [H-3] arachidonic acid-labelled Raw 264.7 cells and PLA2 activity using 1-palmitoyl-2-[C-14] arachidonyl phosphatidylcholine ([C-14]AA-PC) and 10-pyrene phosphatidylcholine in vitro. Key findings Lutein suppressed the release of arachidonic acid and inhibited Raw 264.7 cell-derived cytosolic Ca2+-dependent PLA(2) (cPLA(2))-induced hydrolysis of [C-14]AA-PC in a dose- and time-dependent manner. In contrast, lutein did not affect secretory Ca2+-dependent PLA(2) (sPLA(2))-induced hydrolysis of [C-14] AA-PC. A Dixon plot showed that the inhibition by lutein on cPLA(2) appeared to be competitive with an inhibition constant, K-i, of 13.6 mu M. Conclusions We suggest that lutein acted as a competitive inhibitor of cPLA(2) but did not affect sPLA(2).

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