ki: 130 μmea4 is a rpla2 inhibitor.rpla2, a calcium-dependent cytosolic phospholipase a2 (cpla2), was initially isolated and characterized from bovine and human red blood cells. with a molecular mass of 42 kda, cpla2 shows biochemical properties similar to cpla2 type iv.
it was found that ea4 was able to inhibit a ca(2+) ionophore-induced arachidonic acid release from both human and bovine red blood cells, demonstrating that this enzyme was responsible for the ca(2+)-dependent arachidonic acid release from mammalian red blood cells [1]. another study found that in mouse hepatoma hepa-1c1c7 cells, ea4 could cause a significant induction of the cyp1a1-mediated ethoxyresorufin o-deethylase activity time- and concentration-dependently, and such induction was accompanied by an increase of the cyp1a1 mrna transcription. morevoer, in human cells including mcf-7 (human breast adenocarcinoma cell line), hepg2 (human hepatocarcinoma), and hl-60 (human promyelocytic cell line), the expression of cyp1a1 mrna could be also induced by ea4 treatment. in addition, cyp1b1 mrna was increased by ea4 in mcf-7 cells [2].
1. shin, h.s.,chin, m.r.,kim, j.s., et al. purification and characterization of a cytosolic, 42-kda and ca2+-dependent phospholipase a2 from bovine red blood cells. the journal of biological chemisty 277, 21086-21094 (2002).2. chun, y.j.,lee, b.y.,yang, s.a., et al. induction of cytochrome p450 1a1 gene expression by a vitamin k3 analog in mouse hepatoma hepa-1c1c7 cells. molecules and cells 12, 190-196 (2001).
