<p><b>OBJECTIVE</b>To explore the
role of
mast cells in the pathogenesis of
ulcerative colitis in
rats with dampness and
heat syndrome, and observe the regulatory effect of
Huangqin decoction on the
mast cells.</p><p><b>
METHODS</b>
Rat models of dampness and
heat syndrome were established by
feeding with high-fat and-
sugar chow,
maintenance of a hot and humid
environment, and intrarectal
administration of 2,4,6-trinitro-
benzene-
sulfonic acid. The model
rats were then randomized into the model group (n=12),
Huangqin decoction group (n=13) and
mesalazine group (n=12). After a one-week
treatment, the inflammatory
cell infiltration was observed using HE
staining, and the number of
mast cells was determined using
toluidine blue staining.
Immunohistochemistry was used to detect the expression of
tryptase, and
serum IL-4 and
IL-6 levels were measured using
ELISA.</p><p><b>RESULTS</b>Compared with the normal control
rats (n=15), the
rats in the model group showed obvious inflammatory
cell infiltration at the lesion site with significantly increased
mast cells and
serum IL-6 level (P<0.05).
Huangqin and
mesalazine significantly lessened inflammatory
cell infiltration and decreased the
mast cell number and
serum IL-6 level after a one-week
treatment.</p><p><b>CONCLUSION</b>The intestinal mucosal immune
cells such as the
mast cells play an important
role in the pathogenesis of
ulcerative colitis associated with dampness and
heat syndrome.
Huangqin decoction can ameliorate the
inflammation, decrease
mast cell number and
tryptase release, and inhibit
IL-6 secretion for
treatment of
ulcerative colitis in
rats with dampness and
heat syndrome.</p>