Effect of lignans isolated from Hernandia nymphaeifolia on reactive oxygen species generation and calcium mobilization in human neutrophils

Abstract

AbstractThe effect of five lignans isolated from Hernandia nymphaeifolia on the reactive oxygen species (ROS) generation (O2– and H2O2) and Ca2+ mobilization in human neutrophils was investigated. The five lignans were epi‐yangambin, epi‐magnolin, epi‐aschantin, deoxypodophyllotoxin, and yatein. All five lignans (25–200 μM) suppressed the ROS generation induced by 20 μM N‐formyl‐methionyl‐leucyl‐phenylalanine (fMLP) and 1 μM phorbol myristate acetate (PMA) without altering the ROS generation induced by 0.1 μM arachidonic acid. In Ca2+‐containing medium, the lignans (50–100 μM) inhibited 20 μM fMLP‐ and 0.1 μM arachidonic acid‐induced increases in the intracellular free Ca2+ levels ([Ca2+]i). In Ca2+‐free medium, the lignans (50–100 μM) inhibited 0.1 μM arachidonic acid‐induced [Ca2+]i increase without changing 20 μM fMLP‐induced [Ca2+]i increase. In Ca2+‐free medium, after depleting intracellular Ca2+ stores with fMLP and arachidonic acid, addition of 3 mM Ca2+ induced Ca2+ influx. However, the lignans inhibited fMLP‐ and arachidonic acid‐induced Ca2+ influx. Collectively, this study shows that the lignans alter ROS generation and Ca2+ signaling in human neutrophils in a multiple manner. Drug Dev. Res. 55:118–126, 2002. © 2002 Wiley‐Liss, Inc.