NIGELLA SATIVA L. has many effects including those on the gastrointestinal tract and trachea and is, therefore, used in the Mediteranean area and in India/Pakistan. Our aim was to investigate the effect of two main constituents,
nigellone and
thymoquinone, on trachea (
antispasmodic effect) and their influence on respiratory clearance. The effects on
Ba (2+)-,
carbachol- and
leukotriene-induced trachea contractions and the transport of the fluorescence
dye rhodamin B concerning ciliary action in the tracheal area were investigated using a microdialysis technique.
Nigellone and high concentrations of
thymoquinone had a concentration-dependent inhibitory effect on the trachea when being contracted by the depolarizing effect of
Ba (2+). The trachea contractions induced by
leukotriene-d (4) were inhibited by
nigellone and by
thymoquinone. The
cholinergic system (stimulation by
carbachol) was hardly involved. The rate of ciliary clearance (mucociliary transport) was slightly modified by a high
thymoquinone concentration (153.0 vs. 505.0 sec/12 mm distance, respectively), and was highly increased by
nigellone (217.5 vs. 505.0 sec/12 mm distance). In conclusion, this study provides evidence for an
antispasmodic effect and an increase in mucociliary clearance for
nigellone but not for
thymoquinone. Altogether the data indicate that
nigellone but not
thymoquinone may be useful in treatment of different
respiratory diseases.