Hawthorn extract inhibits human isolated neutrophil functions

Hawthorn extract is a popular herbal medicine given as adjunctive treatment for chronic heart failure. In contrast to the cardiac properties of hawthorn extract, its anti-inflammatory effect has been scarcely investigated. This study examines the effects of a dry extract of leaves and flowers of Crataegus laevigata on various functional outputs of human neutrophils in vitro. Incubation of human neutrophils obtained from peripheral blood of healthy donors with C laevigata extract (0.75-250 mu g/ml) inhibited N-formyl-Met-Leu-Phe (FMLP)-induced superoxide anion generation, elastase release and chemotactic migration with potency values of 43.6,21.9, and 31.6 mu g/ml, respectively. By contrast, serum-opsonized zymosan-induced phagocytosis was unaltered by plant extract. C laevigata extract (125 mu g/ml) reduced FMLP-induced leukotriene B(4) production and lipopolysaccharide-induced generation of tumour necrosis factor-alpha and interleukin-8. Extract inhibited FMLP-induced intracellular calcium signal with potency of 17.4 mu g/ml. Extract also markedly inhibited the extracellular calcium entry into calcium-depleted neutrophils, and the thapsigargin-induced intracellular calcium response. In conclusion, C laevigata extract inhibited various functional outputs of activated human neutrophils which may be relevant to the pathophysiology of cardiac failure. (C) 2008 Elsevier Ltd. All rights reserved.