Erucic acid and erucic acid anilide-induced oxidative burst in human polymorphonuclear leukocytes

Human polymorphonuclear leukocytes (PMNL) were exposed to erucic acid or erucic acid anilide to explore their effects on the production of reactive oxygen species (ROS) and the levels of free intracellular calcium. The compounds did not change the levels of intracellular calcium, but both dose-dependently induced respiratory burst in PMNL. Maximal production of ROS by erucic acid exceeded that induced by its anilide 13-fold. A protein kinase C inhibitor, Ro 31-8220, completely inhibited erucic acid and erucic acid anilide-induced production of ROS. Neither erucic acid nor erucic acid anilide modified FMLP-induced production of ROS. However, erucic acid (500 microM) amplified 5 nM PMA-induced ROS production 1.8-fold, but did not have this effect at a lower PMA concentration. On the contrary, erucic acid anilide inhibited PMA-induced oxidative burst, and shifted the peak ROS production induced by PMA to a later time-point. The present results show that aniline moiety modifies the effects of erucic acid on the activation of PMNL, and suggest that both erucic acid and erucic acid anilide may activate PMNL through a protein kinase C-dependent mechanism.