Haemanthus coccineus extracts (
HCE) have traditionally been used to treat a variety of diseases, like febrile colds or
asthma. Since new therapeutic options against inflammatory processes are still urgently needed, we aimed to pharmacologically characterise the anti-inflammatory potential of HCEin vitro and in vivo and to identify the underlying bioactive component(s). The action of
HCE on oedema formation and leucocyte infiltration were analysed in two murine models of
inflammation (dermal oedema induced by
arachidonic acid and
croton oil; kidney injury caused by unilateral
ureteral obstruction). The interaction of leucocytes with endothelial cells (ECs) as well as the activation parameters of these two cell types were analysed. Moreover, the nuclear factor κB (NFκB) pathway was investigated in detail in ECs. Using different fractions of
HCE, the bioactive principle was identified. In vivo,
HCE (450 mg/kg orally or 2 mg/kg intraperitoneally) inhibited oedema formation, leucocyte infiltration and
cytokine synthesis. In vitro,
HCE (100-300 ng/ml) blocked leucocyte-EC interaction as well as the activation of isolated leucocytes (
cytokine synthesis and proliferation) and of primary ECs (adhesion molecule expression).
HCE suppressed NFκB-dependent gene transcription in the endothelium, but did not interfere with the NFκB activation cascade (IκB degradation, p65 nuclear translocation and NFκB
DNA-binding activity). The
alkaloid narciclasine was elucidated as the bioactive compound responsible for the anti-inflammatory action of
HCE. Our study highlights
HCE and its main
alkaloid narciclasine as novel interesting approach for the treatment of
inflammation-related disorders.