Naturally appearing N-feruloylserotonin isomers suppress oxidative burst of human neutrophils at the protein kinase C level

N-feruloylserotonin (n-f-5ht) isomers,isolated from seeds of leuzea carthamoides (wild) dc,inhibited dose-dependent oxidative burst in human whole blood and isolated neutrophils in vitro,which were measured by luminol- and/or isoluminol-enhanced chemiluminescence in the following rank order of stimuli: pma > opz > calcium ionophore a23187. in isolated neutrophils that were stimulated with pma,n-f-5ht isomers were effective against extracellular and intracellular reactive oxygen species. liberation of atp,analysis of apoptosis,and recombinant caspase-3 activity revealed that n-f-5ht isomers,used in concentrations up to 100 μm,did not alter the viability and integrity of isolated neutrophils. western blot analysis documented that in concentrations of 10 and 100 μm,n-f-5ht isomers significantly decreased pma-induced phosphorylation of pkc α/β ii. the results suggest that n-f-5ht isomers are an effective,naturally occurring substance with a potent pharmacological effect on the oxidative burst of human neutrophils. it should be further investigated for its pharmacological activity against oxidative stress in ischemia-reperfusion,inflammation and other pathological conditions. copyright © 2011 by institute of pharmacology polish academy of sciences.