Sodium azulene sulfonate is a water-soluble derivative of
azulene which is an antiinflammatory component of chamomile of the family of Asteraceae.
Sodium azulene sulfonate is clinically used as a therapeutic agent in the treatment of
pharyngitis as well as other inflammatory diseases such as
tonsillitis,
stomatitis and
conjunctivitis. There has been no documentation on the effect of
sodium azulene sulfonate on
pharyngitis in laboratory models, probably because of no availability of such models. We recently established a
pharyngitis model using
capsaicin application on pharyngeal mucosa in rats. The present study investigated the antipharyngitis activity of
sodium azulene sulfonate comparing with those of
ruthenium red (
vanilloid receptor antagonist, 8.5 and 85 mg/ml),
ascorbic acid (antioxidative compound, 100 microg/ml),
povidone iodine (gargle as
disinfectant, oxidative compound, 5 and 20 mg/ml) and
diclofenac sodium (
cyclooxygenase inhibitor, 0.1 and 1 mg/ml). As an antipharyngeal effect, the
capsaicin-induced plasma exudation in the pharyngeal mucosa of the rat was evaluated. The
capsaicin-induced plasma exudation in the pharyngeal mucosa was inhibited by
sodium azulene sulfonate (100 and 200 microg/ml) as well as
ruthenium red and
ascorbic acid, but not by
povidone iodine and
dicrofenac sodium;
povidone iodine rather promoted the plasma exudation. In conclusion, the antipharyngitis effect of
sodium azulene sulfonate was demonstrated for the first time in a laboratory model. Although the mechanism by which
sodium azulene sulfonate inhibited the
capsaicin-induced
pharyngitis is not yet unraveled, antioxidative effect, but not inhibitory effect on
cyclooxygenase pathway, might be involved.